System, nozzle, and method for coating elastic strands.

(54) Title: SYSTEM, NOZZLE AND METHOD TO COVER ELASTIC THREADS.

(54) Title: SYSTEM, NOZZLE, AND METHOD FOR COATING ELASTIC STRANDS.

(57) Summary

A contact nozzle (2) for coating an elastic strand (12) with an adhesive (14). Air (18) is discharged into the adhesive (14) in contact with the strand (12), causing the adhesive (14) to spread over the entire periphery of the strand (12). The air (18) assists with the release of the adhesive (14) from the nozzle (2) and also cleans the nozzle (2) to prevent build-up of adhesive on the nozzle.

(57) Abstract

A contad nozzle (2) for coating an elastic strand (12) with an adhesive (14). Air (1 8) is discharged at the adhesive (14) in contad with the strand (12), causing the adhesive (14) to spread around the periphery of the strand (12). The air (18) assists with release of the adhesive (14) from the nozzle (2) and also cleans the nozzle (2) to discourage adhesive buildup on the nozzle (2).

<img file="MX352005B_D0001.tif" />

PATENT TITLE No. 352005

Holders): NORDSON CORPORATION

Address: Clemens Road, Westlake, Ohio, 44145-1119, USA

D nomination: SYSTEM, NOZZLE AND METHOD FOR COATING ELASTIC THREADS.

Classification: CIP: A61F13 / 15; B05B15 / 02; B05C5 / 02; D06B3 / 04; D06B11 / 00; D06B15 / 09

CPC: B05B15 / 02; B0 $ B15 / @ 268; B06C5 / 0241; B05C11 / 06; B05D1 / 02; B05D1 / 265;

B05D3 / 042; B29C65 / 525; B29o66 / 7294; D06B3 / 045; D06B15 / 09;

B29K2913 / 00; B29L2031 / 4878

Inventor (s): JOEL E. SAINE; CHARLES P .. &amp; WZER '-_and

APPLICATION 'r

Number; ^J

MX / a / 2013/011885 ,, · '- · 10. April 2012. . .

Country: PoLÜaY * t Number:

US. Q1 April W201'1 '61 / 474,129

Validity: Twenty years ¹ ' , ^;,

Expiration Date: April 10, 2032

Issue Date: November 7, 2017.

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The reference patent is granted based on the articles 1^or, 2 * section V, 6th section Ü, and 59 of the Industrial Property Law.

In accordance with article 23 of the Industrial Property Law, this patent has a validity of twenty years, non-extendable, counted from the date of filing of the international application and the maximum payment of the fee to maintain all rights.

Whoever subscribes to this title will have it^!®ois, Articles 6^or factions III and? » 2nd bis of the Industrial Property Law (Official Gazette of the Federation (b'OvF) 06/27/1991. amended on 02/88/1994. aS / 10 / ΊΛ 12/26/1997, 05/17/1999, 01/26/2004, 06/16/2005, 01/25/2006, 05/06/2009, 06/01/2010, 18/0 ^ 2010, 06/28/2010, 01/27/2012 and 09 / 04 / 2012X articles 1 ", 3^orfraction V subsection a), 4^or and 12th sections I and III of the Regulations of the Mexican Institute of Industrial Property (DOf WIÍIW »: amended, 07/01/2002, 07/15/2004, 07/28/2004 and 09/07/2007); items 1^or, 3^or, 4^or, 5^or fraction V part a). 16 sections 6 ^ ϋΙ'ν ,, ΪΟ ,, όβΙ Estetqfg, Orgpsfajjltaloabtato ^ exican of Industrial Property (DOF 12/27/1999, amended 10/10/2002, 07/29/2004; 154ί | © 2β04 &lt;Λ Agreement that delegates powers to the Directors

Deputy Generals, Coordinator, Divisional Directors ^ / htutarésede · Igs Oíicinaa ^^ officers, Divisional Deputy Directors, Departmental Coordinators and other subordinates of the Mexican Institute of 12/15/1999, reformed on 02/04/2000, 07/29/2004,

08/04/2004 and 09/13/2007). '~

This document is signed with an advanced electronic signature (FIEL), based on articles 7 BIS 2 of the Industrial Property Law; 3 of its Regulations, and 1 section III, 2 section V, 26 BIS and 26 TÉR of the Agreement establishing the guidelines for the use of the Payment and Electronic Services Portal (PASE) of the Mexican Institute of Industrial Property, in the procedures indicated.

THE DIVISIONAL DIRECTOR OF PATENTS

NAHANNY CANAL REYES

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Original string:

NAHANNY MARISOL CANAL REYES | 00001000000403252793 | Administration Service

Tax | 1695 || MX / 2017/89924 | MX / a / 2013/011885 | PCT patent title | 1220 | RRGO | Page (s)

1 | Ds4A88oykCUSn5BPhNVJs7L1Ow4 =

Digital stamp:

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Arenal No. 550 Floor 1 Pueblo Santa María Tepepan. Xochimilco, 16020. Mexico City.

55) 53340700 vAvw.gob.mx/impi

<img file="MX352005B_D0003.tif" />

&gt;5

SYSTEM, NOZZLE, AND COATING METHOD IWIFTIUFLIll

FIELD OF THE INVENTION

This invention generally relates to fluid dispensing systems, nozzles, and methods for applying adhesive to one or more strands of stretched elastic material.

BACKGROUND OF THE INVENTION

Liquid adhesive, such as temperature and / or pressure sensitive adhesive, is applied to one or more stretched strands of elastic material or a nonwoven substrate during the manufacture of disposable hygiene products such as diapers, adult incontinence products and feminine hygiene products to form different elastic structures that are part of the hygiene product. For example, in a diaper one or more stretched elastic strands are attached between the backsheet and the topsheet around the leg opening such that the diaper fits snugly around the baby's leg. This is commonly referred to as the leg elastic application. One or more stretched elastic strands are also attached to different areas of the diaper during the construction of the leg and waistband. Two measurements that are commonly used when evaluating the effectiveness of the Mexican institute

OF THE MCPIETY &amp;

bonding between the tissues are the stretched elastic strands and the substrates not resistance to creep and retraction force. Creep resistance is a measure of how well adhered elastic strands stay in position relative to nonwoven substrates. A high level of creep resistance is desired because creep will cause a strand to disengage from the nonwoven substrate and contract, thereby promoting the elasticity and sealing capabilities of the hygiene product. Retraction force is a measure of how far the attached elastic strand can be retracted when tension on the strand is released. A high level of retraction force is also desirable because a low level of retraction force renders the elasticity of the elastic strand and the hygiene product unsuitable for its intended purposes, including product comfort and sealability. . The adhesive is applied to one or more stretched elastic strands using a non-contact dispensing system or a contact dispensing system.

In the conventional non-contact dispensing system, the adhesive is dispensed as a continuous strand and moves in a controlled pattern when the strand is impacted with air. Different types of nozzles are used in conventional non-contact dispensing systems resulting in₃ IMPl ^

INSTITUTE MEXICANO DE LA MOriEDAO INDUSTRIAL different controlled patterns for the adhesive strand. The non-contact dispensing system using a spiral nozzle moves the adhesive strand back and forth in a helical or spiral pattern while in the air before contacting the stretched elastic strand. The helical or spiral pattern of the adhesive strand has a component in the direction of movement of the stretched elastic strand and another component transverse to the direction of motion of the stretched elastic strand. CF® Nozzles (also identified as Controlled Fiberization ™ Nozzles) and Sure Wrap® Nozzles, available from Nordson Corporation of Westlake, Ohio, are spiral nozzles that are used to form such a helical pattern with a strand of adhesive.

In other non-contact dispensing systems using a melt blow nozzle, the adhesive strand moves back and forth in an oscillating pattern such as a sinusoidal pattern or the like while airborne prior to contacting the stretched elastic strand. . The oscillating pattern of the adhesive strand is in a plane perpendicular to the movement of the stretched elastic strand.

In the non-contact dispensing system using melt blow nozzles or spiral nozzles, the adhesive strand must be carefully controlled to ensure that the adhesive strand is dispensed under reduced elasticity to ensure that the strand is ^^^ lae ^^^ dhe sivo sufficiently wraps around the elastic strand. In this regard, the plurality of air jets used to coil the adhesive strand in Controlled Fiberization ™ and Sure Wrap® nozzles are positioned and tilted with a high degree of precision to cause movement of the adhesive strand. . If one of the air holes delivered by the air jets becomes blocked by adhesive material or debris during operation, the pattern of that is generally disrupted or unbalanced, leading to an uncontrolled adhesive bead pattern. The uncontrolled adhesive strand pattern causes a deposition of unwanted adhesive on the strand or away from the strand as a whole. The adhesive strand in these non-contact dispensing systems must also exhibit a relatively high viscosity to be adequately controllable in flight. The Sure Wrap® nozzle operates using hot melt adhesives with viscosity in the range of 10,000 centipoise to 15,000 centipoise and the Controlled Fiberization ™ nozzle operates using hot melt adhesives with viscosity in the range of 4,000 centipoise to 15,000 centipoise.

ΙΜΡΚ

MEXICAN INSTITUTE

FROM PR.QWfDAS

INDUSTRIAL

Still another type of non-contact dispensing system uses an adhesive nozzle to extrude an adhesive bead onto a stretched elastic strand that rotates as it passes through the adhesive nozzle without the use of any process air in the adhesive bead. The stretched elastic strand is rotated about its axis and moved by means of a pressure roll assembly upstream of the adhesive nozzle. As a result, the continuous strand of adhesive is deposited in a generally spiral pattern along the length of the stretched elastic strand. However, these types of non-contact dispensing systems can be impractical because it is difficult to rotate or twist the elastic strand in a predictable manner at high production line speeds. Despite the above difficulties, non-contact dispensing systems are widely used because the resulting application of adhesive to stretched elastic strands results in a high level of both creep resistance and retraction force.

One type of contact dispensing system uses a slit coating nozzle that includes one or more slots configured to be filled with extruded adhesive. A stretched elastic strand moving through the slots will be surrounded with the extruded adhesive in the corresponding slot. Consequently, the elastic strand

<img file="MX352005B_D0004.tif" />

The stretch is coated as the grooves in the strand nozzle are pulled through the slit coating. Slit coating nozzles do not have the strand control difficulties discussed above because the adhesive does not discharge onto an airborne strand. Contact dispensing systems using these slit coating nozzles tend to have difficulty adequately coating the bottom surface of the stretched elastic strand. If the underside of a strand is not properly coated, there is poor bond between the elastic strand and a nonwoven substrate, resulting in a low level of creep resistance. In order to effectively coat the lower surface of the elastic strand, the flow rate of the adhesive within the groove is commonly increased to a substantial extent, resulting in a relatively thick coating of adhesive. This thick adhesive coating effectively bonds the elastic strand to the substrate and improves creep resistance, but because the strand is heavily coated, its ability to shrink is impaired and results in poor shrinkage strength. The amount of adhesive dispensed to form the thick coating also tends to drip undesirably from the strand, IMPI

INSTITUTE «XICANO

OF THE INDUSTRIAL PROPERTY elastic over other equipment, especially when the production line stops. However, a contact dispensing system that uses a slit coating nozzle to apply adhesive to stretched elastic strands is highly repeatable and consistent.

There is a need, therefore, for a pressure sensitive adhesive dispensing system, nozzle, and method that provides optimum adhesive coating characteristics on an elastic strand, including a high level of creep resistance and a high level of retraction force.

<img file="MX352005B_D0005.tif" />

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment of the invention, a contact nozzle is configured to contact coating at least one stretched elastic strand with an adhesive and then discharge pressurized air toward the adhesive over the strand. For example, a first strand moves in a machine direction and includes a periphery with a top surface. The contact nozzle includes a nozzle body having a first slot for receiving the first strand. The contact nozzle also includes a first adhesive passage that is formed in the nozzle body and terminates in a first adhesive hole that communicates with the first slot. The first adhesive hole is' ^ Sftp to be directed on the upper surface of the strand to deliver the adhesive in contact with the upper surface of the first strand. The contact nozzle also includes a first air passage positioned proximal to the first adhesive passage and terminating in a first air hole positioned downstream of the first adhesive hole in the machine direction. The first air hole is adapted to be directed towards the upper surface of the first strand and is adapted to discharge air into the adhesive in contact with the first strand, thus causing the adhesive to spread over the entire periphery of the first strand. strand.

The air discharged from the first orifice is a pressurized air flow. In addition to spreading the adhesive, this air flow also keeps the nozzle body free of adhesive build-up which would eventually char and adversely affect the operation of the contact nozzle. Pressurized airflow can be used with any type of nozzle and contact coating process to achieve these benefits. The combination of a contact coating process with the additional discharge into the adhesive on the strand conveniently provides an adhesive coated strand along substantially its entire periphery.

The process causes the thickness of the coating to vary along the length of the strand to maintain the elasticity of the strand. To this end, when the coated strand is bonded to one or more nonwoven substrates, such as in the construction of a diaper, the adhesive forms a bond between the substrates and the strand that exhibits desirable levels of creep resistance and strength. Shrinkage is believed to be the result of thickness irregularities in the adhesive coating. Furthermore, the first strand is coated with the adhesive around the entire periphery without a risk that an adhesive filament, such as in a non-contact dispensing process, will be uncontrolled when impacted with the process air. Such uncontrolled filament could lead to adhesive deposition at indeterminate or undesirable locations, including outside the elastic strand.

In an alternative or additional aspect, the first air passage is formed in the nozzle body. The nozzle body has a rear surface that intersects the first groove at an adhesive release edge. More specifically, the rear surface and the first groove define an interior angle between them at the adhesive release edge in an upstream direction from the

IMPIAS n Mexican institute

Λ INDUSTRIAL PROPERTY back surface, the interior angle being an acute angle. The one in the first hole is discharged along the back surface to assist with the release of adhesive from a nozzle body at an adhesive release edge. In this regard, the air discharged along the rear surface of the first air hole is adapted to impact the adhesive on the first strand at an acute angle relative to the machine direction.

In another alternative or additional aspect, the contact nozzle includes a mounting surface on the nozzle body that is adapted to be coupled to a module for supporting the nozzle body. The mounting surface includes an adhesive inlet configured to receive adhesive from the module. A longitudinal axis defined through the first adhesive hole in at least a portion of the first adhesive passage intersects the mounting surface at an acute angle. Discharge from the first hole impacts the adhesive on the strand at an acute angle. The acute angle can be in a range from about 50 degrees to about 80 degrees.

In another alternative or additional aspect, the nozzle also includes an air discharge control device operatively coupled to the first air passage. The

II Μ ιι IMPI ¹¹ MEXICAN IKSTnVTO

The industrially owned air discharge control device is operable to intermittently block the flow of air through the first air passage and the first air hole. In one example, the air discharge control device causes the air flow to be non-continuous. In another example, the air discharge control device causes the flow to be pulsed in a periodic manner. The air discharge control device, for example, can be a mechanical device or an air control solenoid valve that selectively blocks the flow of air through the first air passage.

In yet another alternative or additional aspect, the nozzle includes a second slot formed in the nozzle body and spaced from the first slot in a lateral direction transverse to the machine direction. The second slot is configured to receive a second strand that moves in the machine direction. The contact nozzle also includes a second adhesive passageway that is formed in the nozzle body and terminates in a second adhesive hole that communicates with the second slot. The second adhesive hole is adapted to be directed at an upper surface of the second strand to deliver the adhesive in contact with the upper surface of the second strand. The contact nozzle also includes a second

<img file="MX352005B_D0006.tif" />

air passage that ends in a second air hole positioned downstream of the second adhesive hole in the machine direction. The second step of is adapted to be directed towards the upper surface of the second strand and adapted to discharge air that the adhesive in contact with the second strand to cause the adhesive to spread over an entire periphery of the second strand. It will be understood that any embodiment of the nozzle can include more than two slots, air passages, and adhesive passages in other embodiments when more than two strands are coated. In this regard, any embodiment of the nozzle can include repeating structural elements that enable similar covering of any number of stretched elastic strands.

In another alternative or additional aspect, the nozzle includes another air passage positioned to the first air passage and also directed at the first strand. Therefore, in this embodiment two air passages can be regulated with respect to each other to cause the adhesive to spread around opposite sides of the periphery of the first strand. Additionally, two air passages per strand provide redundancy in the event that one of the air passages becomes blocked, as any air passage is operable to spread the adhesive around the first strand. By

<img file="MX352005B_D0007.tif" />

₁₃ IMPI

INSTITUTE ββΙΙΟΛΝΟ

FROM THE RKOrii * AL&gt;

INDUSTRIAL example, in the embodiment described above that includes the first and second air passages for the corresponding first and second elastic strands, the contact nozzle may also include a third air passage formed in the nozzle body and adapted to direct air into the first strand, and a fourth air passage formed in the nozzle body and adapted to direct air into the second strand. The two air passages per strand may be staggered along the machine direction such that the air from each of these air passages hits the first strand at different locations along the machine direction. Alternatively, these two air passages can be collinear or aligned with each other in a plane perpendicular to the machine direction such that the air from each of these air passages hits the first strand in approximately the same location along the way. along the machine direction.

In another alternative or additional aspect, the contact nozzle further includes an expansion chamber formed in the nozzle body and in communication with the first adhesive hole. The expansion chamber is sized to enable row swelling of the adhesive exiting the first adhesive hole. In these embodiments, the contact nozzle also includes a strand guide at the

<img file="MX352005B_D0008.tif" />

<img file="MX352005B_D0009.tif" />

nozzle body. The guide for positioning the first strand to strand is relative to — Ί'ί expansion chamber. As described in greater detail below, the expansion chamber or strand guide may be partially or fully defined by the first slot in certain embodiments consistent with the present invention. The strand guide may alternatively be separate from and coupled to the nozzle body in the embodiments.

In yet another alternative aspect, the first air passage is located in an air supply line. The air supply line may be coupled to the nozzle body in one embodiment, or in another embodiment, it may be separate from the nozzle body and positioned downstream of the nozzle body in the machine direction. Again, the contact nozzle in this aspect includes a rear surface of the nozzle body that intersects the first groove at an adhesive release edge, the rear surface and first groove define an acute angle at the adhesive release edge of such that the air in the air supply line impacts the adhesive at an acute angle from the machine direction. The acute angle can be in the range of about 50 degrees to about 80 degrees.

<img file="MX352005B_D0010.tif" />

₁₅ IMPI

INSTITUTE MEXICANO ¿ELAfWHEDAÍ)

INDUSTRIAL

In another embodiment of the invention, a contact nozzle for coating at least one elastic strand includes a nozzle body having an elongated first adhesive chamber to receive the first strand. The elongated first strand of adhesive includes a surface of the first chamber configured to face the strand. The contact nozzle also includes a first adhesive passage formed in the nozzle body and terminating in a first adhesive hole on the surface of the first chamber. The first adhesive hole is adapted to be directed to the upper surface and the first strand to deliver the adhesive in contact with the upper surface of the first strand. The contact nozzle also includes a first air passage positioned proximal to the first adhesive passage and terminating in a first air hole positioned downstream of the first adhesive hole in the machine direction. The first air hole is adapted to be directed toward the upper surface of the first strand and is adapted to discharge air into the adhesive in contact with the first strand, thereby causing the adhesive to spread over the entire periphery of the first strand. In addition to spreading the adhesive, this airflow also assists with the release of the adhesive from a nozzle body and keeps the nozzle body free of

<img file="MX352005B_D0011.tif" />

IMPI

6 ΐΝΠΓΤυτο wfwcano

FROM INDUSTRIAL FHOPIBILITY adhesive build-up which would eventually char and adversely affect the operation of the contact nozzle.

In one aspect, the contact nozzle further includes a strand guide that may be integral with or coupled with the nozzle body, the strand guide is adapted to position the first strand relative to the first elongated adhesive chamber. To this end, the nozzle body may include a rear surface such that the first elongated adhesive chamber extends between the strand guide and the rear surface. In one example, the strand guide is positioned relative to the first elongated adhesive chamber such that a gap between the surface of the first chamber and the top surface of the strand remains constant in thickness along the length of the strand. the first elongated adhesive chamber. In an alternate example, the strand guide is positioned relative to the first elongated adhesive chamber such that the gap is reduced in thickness along the length of the first elongated adhesive chamber. In each of these examples, the space defines an expansion chamber dimensioned to enable row swelling of the adhesive exiting the first adhesive hole.

This swelling of the row causes an initial extension of the

ΙΝ. · ΓΓΠ · υΤΟ MEXICAN

OF THE PROPERTY

INDUSTRIAL adhesive around the periphery of the strand as the strand moves through the first elongated adhesive chamber.

In yet another embodiment of the invention, a contact nozzle for coating at least one elastic strand includes a nozzle body having a front side, a rear side, and a first V-shaped notch for receiving the first strand. The first V-shaped notch extends between the front and rear sides of the nozzle body. The contact nozzle also includes a first adhesive passage formed in the nozzle body and terminating in a first adhesive hole that communicates with the V-shaped notch. The first adhesive hole is adapted to be directed to the surface. top of the first strand to deliver the adhesive contacting the top surface of the first strand. The contact nozzle also includes an expansion chamber formed in the nozzle body and communicating with the first adhesive hole. The expansion chamber is sized to enable row swelling of the adhesive exiting the first adhesive hole. The contact nozzle also includes a first air passage positioned close to the first adhesive passage and terminating in a first air hole positioned downstream of the first adhesive hole in the direction of the

DE LA fropeda: ζ INDUSTRIAL machine. The first air hole is adapted to be directed towards the upper surface of the first strand and is adapted to discharge air into the adhesive in contact with the first strand, thus causing the adhesive to spread over the entire periphery of the first strand. strand. In addition to spreading the adhesive, this air flow also assists with the release of the adhesive from the nozzle body and keeps the nozzle body free of adhesive build-up which would eventually char and adversely affect the operation of the contact nozzle.

In one aspect, the adhesive is mechanically separated around the periphery of the strand by means of the V-shaped notch. To this end, the V-shaped notch may include first and second converging surfaces connected at an upper edge and which define an angle between converging surfaces in the range of 60 degrees to 90 degrees. The V-shaped notch extends both upstream and downstream in the machine direction from the expansion chamber. Furthermore, the V-shaped notch defines a strand guide adapted to position the first strand with respect to the expansion chamber.

In another aspect, the contact nozzle includes alignment pins attached to the front side of the

MEXICAN INSTITUTE OF PROPERTY INDUSTRIAL nozzle and located upstream in the machine direction from the V-shaped notch. The alignment bolts are adapted to prevent the first strand from coming out of the V-shaped notch during adhesive application. .

In another embodiment of the invention, an adhesive dispensing system for coating at least one elastic strand moving in the direction of a machine with adhesive includes a module configured to receive a supply of adhesive. The adhesive dispensing system also includes a contact nozzle attached to the module. The contact nozzle includes a nozzle body with a first slot for receiving a first strand. The contact nozzle also includes a first adhesive passage formed in the nozzle body and terminating in a first adhesive hole that communicates with the first slot. The first adhesive hole is adapted to be directed to an upper surface of the first strand to deliver the adhesive in contact with the upper surface of the first strand. The adhesive dispensing system also includes a first air passage positioned proximal to the first adhesive passage and terminating in a first air hole positioned downstream from the first adhesive hole in the machine direction. The first hole of

j.

<img file="MX352005B_D0012.tif" />

Air is adapted to be directed towards the upper surface of the first strand and adapted to discharge air in the adhesive in contact with the first strand, causing the adhesive to spread over the entire periphery of the first strand. In addition to spreading the adhesive, this air flow also assists with the release of the adhesive from the nozzle body and keeps the nozzle body free of adhesive build-up which would eventually char and adversely affect the operation of the contact nozzle.

In one aspect, the first air passage is formed in the nozzle body. The nozzle body may include an expansion chamber that communicates with the first adhesive hole and is dimensioned to enable row swelling of the adhesive exiting the first adhesive hole. The contact nozzle may also include a strand guide that is integral with or coupled to the nozzle body for positioning the first strand with respect to the expansion chamber. In one embodiment, the first groove includes an elongated adhesive chamber adapted to receive the first strand. The elongated adhesive chamber extends from the strand guide to a rear surface of the nozzle body and includes a first chamber surface that includes the adhesive hole. The

<img file="MX352005B_D0013.tif" />

IMPI

INSTITUTE · MEXICANO 2 1 M LA puonEDAü

INDUSTRIAL first chamber surface is spaced from strand ^ ®paxa ^ = * »° ^ define a space that defines an expansion chamber sized to enable row swell of the adhesive as the adhesive moves through the elongated adhesive chamber . In another embodiment, the first slot includes a V-shaped notch that defines the strand guide that extends between the front and rear sides of the nozzle body. The V-shaped notch is defined by two converging surfaces that are connected at the upper edge that intersects the expansion chamber.

In yet another embodiment of the invention, a method of contact coating at least one elastic strand with an adhesive includes moving a first strand in a machine direction relative to a contact nozzle. The method also includes discharging the adhesive from the contact nozzle onto an upper surface of the first strand. The pressurized air is then discharged into the adhesive in the first strand, causing the adhesive to spread over the entire periphery of the strand. The pressurized air also assists with the release of adhesive from the contact nozzle and keeps the nozzle body free of adhesive build-up.

In a further alternative aspect, air is discharged from the air hole in the contact nozzle. The air

ΙΜΡϊ ^ ^{2 2 ΙΝ5Τ}^ Ι? ®

INDUSTRIAL also discharges at an acute angle to the machine direction measured between the direction of the air discharge and the first upstream strand of air in the machine direction. For example, the acute angle from the machine direction may range from about 50 degrees to about 80 degrees. Therefore, the air intersects the first strand at the acute angle. A smaller acute angle can be chosen to make the air flow more parallel to the movement of the strand, thereby enabling higher air pressures to be used such as during startup of the adhesive dispensing system.

In another alternative or additional aspect, multiple streams of air are discharged into the adhesive in the strand to cause the adhesive to spread around opposite sides of the periphery of the strand. The multiple streams of air can be staggered in the machine direction such that multiple streams of air hit the strand at different locations along the machine direction. Alternatively, the multiple streams of air are aligned in a plane perpendicular to the machine direction such that multiple streams of air strike the strand at approximately the same location along the machine direction.

IMPI

INSTITUTE MEXICANO iwjiiivi Μ, Αβκη *

In another alternative or additional aspect, the air - _, || 1 ~~ rw ~~~ —i - * ^ * ^ * · ^⁵*** Pressurized continuously discharges into the adhesive in contact with the first strand, causing substantially continuous spread of the adhesive around the first strand. Alternatively, pressurized air is discharged non-continuously into the adhesive in contact with the first strand, causing substantially non-continuous spread of the adhesive around the first strand. In one example, this non-continuous extension can be caused by periodic pulsation of pressurized air. Regardless of the air discharge method, the adhesive is spread around the periphery of the first strand such that the adhesive defines thickness irregularities along the length of the first strand.

In one aspect, the method includes moving the first strand through an elongated adhesive chamber in communication with the first adhesive hole and spreading the adhesive in contact with the upper surface of the first strand. The first strand can be moved through the elongated adhesive chamber so that it is generally parallel to a surface of the chamber including the first adhesive hole. Alternatively, the first strand can be moved through the elongated adhesive chamber to move closer to the chamber surface along the length

4 of the elongated adhesive chamber. In another aspect, ^ T ^ method includes moving the first strand through a V-shaped notch formed in the contact nozzle. The V-shaped notch mechanically moves the adhesive into the strand to spread the adhesive across the entire periphery of the strand.

The different characteristics of the modalities described above can be combined in any configuration as desired. For example, all embodiments of the nozzle are capable of coating more than one stretched elastic strand by duplicating the structural elements that are used to coat the first stretched elastic strand. Various additional features and advantages of the invention will become more apparent upon review of the following detailed description of illustrative embodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic side view of one embodiment of a contact nozzle for use with an adhesive dispensing system in accordance with the present invention.

Figure 2A is a schematic side view of another embodiment of an adhesive dispensing system in a nonwoven assembly process.

Figure 2B is a perspective view of the rear side of the nozzle of Figure 2A.

Figure 2C is a rear side view of the nozzle of Figure 2A, showing multiple air passages in dotted lines.

Figure 2D is a detailed view of the rear side of the nozzle of Figure 2A, showing the adhesive chamber and access slot.

Figure 3A is a side cross-sectional view of the nozzle of Figure 2B along line 3-3, illustrating the internal flow paths for adhesive and air.

Figure 3B is a detailed side cross-sectional view of the nozzle of Figure 3A, further illustrating the adhesive release edge of the nozzle body.

Figure 3C is a side cross-sectional view of the nozzle similar to Figure 3A, except that the strand is in an angled orientation relative to the nozzle body and the adhesive chamber.

Figure 3D is a detailed side cross-sectional view of the nozzle of Figure 3C, further illustrating the adhesive release edge of the body.

<img file="MX352005B_D0014.tif" />

<img file="MX352005B_D0015.tif" />

ΐΝΒΠΤσο MEXICAN NOZZLE INDUSTRIAL PROPERTY.

Figure 4 is a perspective cross-sectional view of the nozzle of Figure 2B along line 3-3, illustrating adhesive spreading over the strand.

Figure 5A is a rear side view of an alternate embodiment of a nozzle, showing multiple air passages in dotted lines.

Figure 5B is a rear side view of another alternate embodiment of a nozzle, showing multiple air passages in dotted lines.

Figure 6 is a partially exploded perspective view of another embodiment of a nozzle.

Figure 7 is a side cross-sectional view of the nozzle of Figure 6 along line 7-7, illustrating the flow paths for adhesive and air.

Figure 8A is a detailed side cross-sectional view of the air discharge control device of Figure 7 in a first position.

Figure 8B is a detailed side cross-sectional view of the air discharge control device of Figure 7 in a second position.

Figure 9 is a perspective cross-sectional view of the nozzle of Figure 6 along line 7-7, illustrating the spread of the adhesive over the

IMPI

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY

<img file="MX352005B_D0016.tif" />

strand with pulsed air.

Figure 10 is a schematic side view of another embodiment of an adhesive dispensing system in a nonwoven assembly process.

Figure 11 is a side cross-sectional view of the adhesive dispensing system of Figure 10, illustrating internal flow paths for adhesive and air.

Figure 12 is a schematic side view of yet another embodiment of an adhesive dispensing system in a nonwoven assembly process.

Figure 13 is a schematic side view of an alternate embodiment of an adhesive dispensing system in a nonwoven assembly process, the adhesive dispensing system includes a V-notch nozzle.

Figure 14A is a perspective view of the rear side of the V-notch nozzle of Figure 13.

Figure 14B is a rear side view of the V-notch nozzle of Figure 13, showing multiple air passages in dotted lines.

Figure 14C is a detailed view of the rear side of the V-notch nozzle of Figure 13, showing the adhesive being applied into one of the notches.

Figure 15A is a side, sectional view of the V-notch nozzle of Figure 14A along line 15-15, illustrating the internal flow paths for adhesive and air and one of the notches without adhesive or a strand located within the notch.

Figure 15B is a bottom view of the V-notch nozzle of Figure 15A, further illustrating the notch and adhesive hole in communication with the notch.

Figure 15C is a side cross-sectional view of the V-notch nozzle similar to Figure 15A, with adhesive material being applied to a strand within the notch.

Figure 15D is a detailed side cross-sectional view of the V-notch nozzle of Figure 15C, further illustrating the adhesive release edge of the V-notch nozzle.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 illustrates a contact nozzle 2 configured for use in an adhesive dispensing system in accordance with the present invention. Contact nozzle 2 receives a stretched elastic strand 12 and applies an adhesive 14 to elastic strand 12 by contacting elastic strand 12 as elastic strand 12 moves in the

<img file="MX352005B_D0017.tif" />

direction of a machine as indicated by arrow 16. The contact nozzle 2 is illustrated in this figure as a generalized contact nozzle 2, and it will be appreciated that a contact nozzle having any particular shape and configuration of in accordance with the principles of the present invention. The pressurized air (hereinafter "air") is then discharged into the adhesive 14 at the elastic strand 12 as shown by the date 18 downstream (with respect to the machine direction 16) from the application of the adhesive 14. Although the air flow is represented by a date 18 originating from the contact nozzle 2 in Figure 1, it will be understood that the air can be discharged from a separate air supply line or by some other method unrelated to the contact nozzle 2 in other embodiments within the scope of the present invention. The air flow further moves or spreads the adhesive 14 around the strand 12, thus resulting in different adhesive coating thicknesses along the length of the strand 12. The air flow also assists the adhesive in its release. contact nozzle 2 and keeps contact nozzle 2 free of adhesive build-up which would eventually char and adversely affect the operation of contact nozzle 2. Air is a pressurized air flow of such

<img file="MX352005B_D0018.tif" />

and the adhesive 14 in effect that could in the adhesive 14 form that the effects of air impacting the strand 12 are in addition to any having the air from the ambient environment as the elastic strand 12 can be in the machine direction 16. The combination of a contact coating process with the additional air discharge into adhesive 14 over strand 12 conveniently provides a strand 12 reliably coated with adhesive 14 along substantially its entire periphery. This process is believed to cause the thickness of the adhesive coating to vary along the length of strand 12 to maintain elasticity of strand 12. In this regard, adhesive 14 forms a coating with a plurality of thicker portions 84a, a plurality of thinner portions 84b, and preferably a plurality of empty locations 84c where there is no adhesive 14 on strand 12. When the coated strand is bonded to one or more nonwoven substrates, such as in diaper construction, the adhesive forms a bond between the substrates and the strand that exhibits desirable levels of creep resistance and shrinkage forces.

Figures 2A-15D illustrate various embodiments of the adhesive dispensing system 10, 310, 410, 510 according to the present invention including a module 15 ³¹ jNSTmiTOMWiCANo coupled with a contact nozzle 19, 110, 312,

Module 15 can be a Universal ™ module obtained from Nordson Corporation of Westlake, Ohio. The Universal ™ module is further described in US Patent Document

States No. 6,676,038 to Gressett Jr. et al. and Gresset Jr. et al., US Patent No. 7,559,487, the disclosures of which are incorporated by reference herein. In each of these exemplary embodiments and consistent with the generalized embodiment shown in Figure 1, the contact nozzle applies an adhesive to an elastic cord by dispensing adhesive from a hole and contact coating the strand with the adhesive adjacent to the hole. . After the adhesive has been engaged with the elastic strand, it is discharged into the adhesive on the strand. The operation of the mode is described in more detail below.

Figures 2A-4 further illustrate an embodiment of an adhesive dispensing system 10 that includes a contact nozzle 19 for coating a strand 12 with an adhesive 14. More particularly, the nozzle 19 coats one or more stretched elastic strands 12 with a hot melt adhesive 14 to form an elastic portion of a hygiene product such as a diaper or sanitary napkin. Nozzle 19 applies hot melt adhesive 14

MEXICAN INSTITUTE

D6 ΙΛ INDUSTRIAL PROPERTY on elastic strand 12 as elastic strand 12 moves in the machine direction through a slot (not shown in Figure 2A) as indicated by arrows 16. Nozzle 19 then discharges pressurized air in the hot melt adhesive 14 as shown by arrows 18 to cause the hot melt adhesive 14 to extend around a periphery 20 of the elastic strand 12. The nozzle 19 uses the hot melt adhesive 14 of a generally low viscosity because the air is discharged into the hot melt adhesive 14 only when the hot melt adhesive 14 is in contact with the strand 12. Since the hot melt adhesive 14 is not dispensed into the air as a filament and is impacted with the process air to move in a controlled pattern, there is no risk of uncontrolled filaments and high viscosity is not needed to maintain the integrity of the filament. Strand 12 then continues in the machine direction to the first and second tie spools 22a, 22b that engage the first and second nonwoven substrates 24a, 24b such as the top and bottom sheets of a typical diaper to strand 12 in a sandwich construction. The hot melt adhesive therefore bonds of nonwoven substrates 24a, 24b and strand 12 to form an elastic portion of a hygiene product.

Although Figure 2A illustrates

<img file="MX352005B_D0019.tif" />

INSTITUTE MEXICANO DE LA PROPERTY,. INDUSTRIAL the first and second nonwoven substrates 24a, 24b as the different sheets of material, the sandwich construction could alternatively be formed by means of a sheet of nonwoven material folded on itself around the strand 12 to form two layers of substrate. Also, the first tie spool 22a and the second tie spool 22b may be staggered or aligned in the machine direction.

It will be understood that the use of directional bolts such as top, bottom, front, rear, and side in the following description is for illustrative purposes only and does not limit the structure or methods to any such orientation. Furthermore, the shape and size of different components of the nozzle 19 described below can be modified according to the needs of the user without departing from the scope of the invention.

Nozzle 19 is shown in greater detail in Figures

2B to 3D. The nozzle 19 includes a nozzle body 30 that includes an upper body portion 32 and a lower body portion 34. The nozzle body 30 also includes an upper side 36, lower side 38, a front side 40 extending between the upper and lower sides 36, 38, and a rear side 42 extending between the upper and lower sides 36, 38. The upper side 36 defines a surface of

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--- INDUSTRIAL - assembly 36 configured to be in contact with the module

fifteen. The upper body portion 32 is generally longer along the machine direction than the lower body portion 34 from the front side 40 to the rear side 42, thus giving the nozzle 19 a conical appearance from the front. upper side 36 to lower side 38. Therefore, the upper body portion 32 defines the connecting portions 44 along the front side 40 and the rear side 42 to align the nozzle 19 with the module 15. The nozzle 19 is attached to the module 15 such that the upper side 36 (ie, the mounting surface) engages the module 15 as well understood in US Patent Nos. 6,676,038 and 7,559,487. In some embodiments, the nozzle body 30 can be of a different shape and size, including but not limited to being formed of stacked plates.

The nozzle 19 further includes an adhesive inlet 50 and an air inlet 52 positioned along the mounting surface on the upper side 36 of the nozzle body 30. The adhesive inlet 50 is surrounded by a seal groove 54 which receives a seal member 56 between nozzle 19 and module 15 previously described. Adhesive inlet 50 is fluidly coupled with a plurality of adhesive passages 58 formed in nozzle body 30

<img file="MX352005B_D0020.tif" />

IMPI

MEXICAN INSTITUTE

Dt THE INDUSTRIAL PROPERTY and which extend within the portion of the lower body.

of the nozzle body 30. Although three adhesive passages 58 are shown in Figure 2C, more or fewer adhesive passages may be coupled to the adhesive inlet 50 in other embodiments of the nozzle 19. Each adhesive passage 58 is spaced apart. adhesive passages 58 adjacent in a lateral direction transverse to the machine direction.

Each adhesive passage 58 delivers the adhesive 14 from the adhesive inlet 50 to an adhesive hole 60 which communicates with a respective slot 62 that is formed near the underside 38 of the nozzle body 30. The slot 62 of this embodiment includes an elongated adhesive chamber 62 as described in greater detail with reference to Figures 3A and 3B below.

In a similar manner, the air inlet 52 is fluidly coupled with a plurality of air passages 64 formed in the nozzle body 30 and extending into the lower body portion 34. Each air passage 64 is positioned proximal to and directly behind the respective adhesive passage 58 within the nozzle body 30. In this regard, each set of adhesive passages 58 and air passages 64 coats a strand 12 that passes through the nozzle 19. Furthermore, each set of adhesive passages 58 and air passages 64 in the illustrated embodiment includes

<img file="MX352005B_D0021.tif" />

IMPI iNsmvro MEXICANO DE LA PWOREDAD INDUSTRIAL only one passage of adhesive 58 and only one passage of air for the corresponding strand 12. As shown in Figures 3A and 3B, it will be understood that at least a lower portion of the adhesive passage 58 and a portion of the air passage 64 are manufactured to be generally parallel to each other, thus avoiding interference between the passages 58. , 64 inside nozzle body 30. Furthermore, it will be understood that the adhesive passage 58 may be machined to include a slight bend at a point between the adhesive inlet 50 and the adhesive hole 60 as shown in Figure 3A or it may be machined to follow a path of the adhesive. level between adhesive inlet 50 and adhesive hole 60 in other embodiments (eg, Figure 15A) without departing from the scope of the present invention. Each air passage 64 is spaced from adjacent air passages 64 in the lateral direction. Each air passage 64 delivers air from the air inlet 52 to an air hole 66 directed to the adhesive 14 in contact with the strand 12. More particularly, the air hole 66 is positioned adjacent a rear surface 68, which is part from the rear side 42 of the nozzle body 30. As such, air discharged from air passage 64 and air hole 66 is directed along rear surface 68 to act on adhesive 14 as strand 12 exits the

<img file="MX352005B_D0022.tif" />

IMPI

MEXICAN INSTITUTE

INDUSTRIAL PROPERTY adhesive chamber 62. As shown in Figures 2D and

3B, the air hole 66 is located on an intermediate surface 69 extending from the rear surface 68. The thicknesses 69a and 69b of the intermediate surface 69 on opposite sides of the air hole 66 are minimized to reduce any eddy currents. which tend to form adjacent oblique surfaces surrounding air hole 66. The eddy current reduction along the intermediate surface 69 makes the delivery of air to the strand 12 more laminar.

Nozzle 19 further includes one or more strand guides 70 positioned proximate nozzle body 30 to guide respective strands 12 into corresponding adhesive chambers 62. Strand guides that are used with spiral nozzles are further described in US Patent No. 7,647,885 to Grane et al. and United States Patent Publication No. 2010/0024997 to Sainé et al., Which is assigned to Nordson Corporation and the disclosures of which are incorporated herein by reference. In the illustrated embodiment, each strand guide 70 is coupled to the nozzle body 30 and includes a guide slot 72 in communication with the corresponding adhesive chamber 62. Guide groove 72 is tapered inward in the direction of the

<img file="MX352005B_D0023.tif" />

<img file="MX352005B_D0024.tif" />

MEXICAN IMPI mctITUTO ^w OF THE INDUSTRIAL MYOPIEPAUS is positioned to travel under air 66. Each machine in such a way that the strand 12 precisely in the adhesive chamber 62 stops the adhesive hole 60 and the strand guide hole 7 0 also defines a lateral width Wi as shown in Figure 2C. Therefore, adjacent sets of adhesive passages 58 and air passages 64 in nozzle body 30 are laterally spaced from one another by a distance above a minimum spacing defined by lateral width W_x of the strand guides 70. In this regard, the provision of only one air passage 64 and only one adhesive passage 58 per strand 12 refers to the less width in the nozzle body 30 than the lateral width Wi of the strand guides 70. For this reason at least, the minimum spacing between multiple strands 12 running through nozzle 19 is dependent on strand guides 70 rather than adhesive passage 58 and air passage 64.

In one example, each strand guide 70 is formed separately and inserted into a corresponding guide cavity 74 in the nozzle body 30 as shown in the figures. In this arrangement, the strand guides 70 are replaceable if the moving strand 12 wears out the guide groove 72. Additionally, the strand guides 70 in this arrangement are formed from stainless steel with a Titanium Nitride coating to resist friction wear. Nozzle 30 is machined from a while the body of

<img file="MX352005B_D0025.tif" />

different material such as aluminum or brass. The strand guides 70 may include only the guide groove 72 as shown or may be modified to include the guide groove 72 and the adhesive chamber 62 in another embodiment that is not illustrated. For this purpose, the strand guide 70 of the illustrated embodiment is formed separately and is located upstream of the adhesive chamber 62. In other embodiments, the strand guides 70 are integrally formed with the nozzle body 30. In this arrangement, the nozzle body 30 can be machined from steel and a Titanium Nitride coating can be used in the area of ​​the integral strand guide 70 to resist frictional wear. In yet another arrangement, strand guides 70 are coupled to nozzle body 30 or are coupled to another structure adjacent to nozzle body 30 such as a module carrying nozzle 19.

Figures 2D, 3A, and 3B further illustrate one of the elongated adhesive chambers 62 (eg, grooves 62) in greater detail. The adhesive chamber 62 includes a chamber surface 76 on the nozzle body 30, the chamber surface 76 which includes the adhesive hole 60 communicates with the adhesive passage 58. The nozzle body 30 further includes an access slot. 77 I know₄₀ IMPI ^what Mexican NnrruTO

D »INDUSTRIAL PROPERTY tends downward from adhesive chamber 62 to underside 38 as shown in Figure 2D. Access slot 77 communicates with adhesive chamber 62 and guide slot 72 in strand guide 70 such that strand 12 can be inserted upward through access slot 77 into guide slot 72 and the adhesive chamber 62 instead of being threaded through those elements. Adhesive chamber 62 is shown as a slot in Figures 3A and 3B, but it will be understood that adhesive chamber 62 can define different shapes and sizes in other embodiments, including being tapered. In embodiments with a tapered adhesive chamber 62, the taper is continuous or stepped. Furthermore, while adhesive chamber 62 and access slot 67 are milled into nozzle body 30 in the illustrated embodiment, alternative embodiments of nozzle 19 may include an adhesive chamber 62 that is formed by means of one or more More apparatus drilled through the nozzle body 30 along the machine direction. An access slot 77 can then be milled between the perforated apparatus and the underside 38 of the nozzle body 30. In one example, an adhesive chamber 62 that includes two perforated fixtures defines a cross-sectional shaped figure at 8, and the access slot 77 can be milled

<img file="MX352005B_D0026.tif" />

₄₁ IMPI¿g ^{4 4} MEXICAN INSTITUTE

OF THE Industrial MOPIETY Cm «within the intersection of the two perforated openings.

Thus, adhesive chamber 62 is in fluid communication with adhesive passage 58 through adhesive hole 60. Guide groove 72 of strand guide 70 positions strand 12 within adhesive chamber 62 to defining a space 78 between chamber surface 76 and an upper surface 80 of strand 12. Space 78 defines an expansion chamber that is dimensioned to allow initial expansion of adhesive 14 within adhesive chamber 62 above strand 12 due to spin swelling effects within adhesive chamber 62. At the In the exemplary embodiment shown, the gap 78 is dimensioned within the range of about 0.0127 cm (0.005 inches) to about 0.0381 cm (0.015 inches). As is well understood in the art, die swelling refers to the phenomenon of a torrent of material swelling in volume after being compressed in a mold or reduced passage (such as adhesive passage 58). Adhesive chamber 62 is substantially filled with adhesive 14 in space 78 such that adhesive 14 is applied to elastic strand 12 as strand 12 moves through adhesive chamber 62. Therefore, the adhesive chamber 62 is configured to promote initial expansion and extension.

<img file="MX352005B_D0027.tif" />

IMPI

MEXICAN INSTITUTE

Say THE INDUSTRIAL PROPERTY of adhesive 14 in this mode. Because- q¹,¹? ^{1 3} Elastic fiber 12 passes through adhesive chamber 62 at a higher rate at which adhesive 14 is supplied to adhesive chamber 62, strand 12 draws adhesive 14 from adhesive chamber 62 in a manner that ensures that the strand 12 is not covered with adhesive 14 and necessary or in excess. Additionally, the space 78 between the chamber surface 7 6 and the upper surface 80 of the strand 12 in combination with the effects of spin swelling causes the adhesive 14 to begin to spread around the periphery 20 of the strand 12 as the strand 12 passes through adhesive chamber 62 as indicated in dotted lines in Figure 3B.

As shown in Figure 2D, the rear surface 68 of the nozzle body 30 also intersects with a lower rear surface 81 at an elongated edge 82. The adhesive chamber 62 and access slot 77 terminate at the lower rear surface 81. Elongated edge 82 includes an adhesive release edge 82a where chamber surface 76 intersects rear surface 68. Chamber surface 76 and rear surface 68 define an interior angle a (Figure 3B) between surfaces 76 and 78 at adhesive release edge 82a. The interior angle a is an acute angle such that

IMPI ⁴ -³ MEXICAN INSTITUTE

OF INDUSTRIAL PROPERTY ^ a_ the adhesive release edge 82a promotes sharp release of adhesive 14 in strand 12 from nozzle body 30. The interior angle a is measured in an upstream direction along the direction of the machine from adhesive release edge 82a. For this purpose, the interior angle a is defined by the nozzle body 30 at the adhesive release edge 82a. In the illustrated embodiment, the acute angle from the machine direction can be in the range of about 50 degrees to about 80 degrees. As the acute angle a becomes smaller within this range (such as the relatively small acute angle a shown in Figure 3B), the air flow from the air hole 66 becomes more parallel to the movement of the strand. 12 along the machine direction, which enables higher pressures to be used for the air flow to spread the adhesive 14 without blowing the adhesive 14 out of the strand 12. Adhesive release edge 82a applies a cleaning or spreading effect to adhesive 14 without contacting strand 12. This spreading effect increases as strand 12 is positioned closer to adhesive release edge 82a.

The air protruded from the air hole 66 along the rear surface 68 as shown by the

<img file="MX352005B_D0028.tif" />

INDUSTRIAL PROPERTY release adhesive 14 from surface arrows 18 also assists with release from nozzle body 30 at adhesive edge 82a. The trailing air traveling 68 cuts the upper surface 80 of strand 12 at a non-perpendicular angle in such a way that it is believed that the formation of any eddy currents around the adhesive release edge 82a is prevented. More specifically, the air strikes the upper surface 80 of strand 12 at the acute angle a described above. Therefore, the adhesive 14 remains attached to the moving strand 12 downstream of the adhesive chamber 62 rather than accumulating in the nozzle body 30. As a result, the risk of the adhesive 14 is substantially reduced or eliminated. builds up in nozzle body 30 and blocks air hole 66.

In the illustrated embodiment, the width of strand 12 in a stretched condition is about 0.020 cm (0.008 inches) to 0.051 cm (0.02 inches). Adhesive hole 60 has a diameter of approximately 0.061 cm (0.024 inches) such that adhesive 14 applied to strand 12 begins to spread around the periphery 20 of strand 12 immediately upon application into adhesive chamber 62 . The air hole 66 has a diameter of approximately 0.051 cm (0.02 inches) at the ₄₅ IMPI ^ ⁴ INSTITUTE MEXICANO E? ^ W¡ £ ¡

OF THE PROPERTY vVwjZJ?

INDUSTRIAL mode illustrated. The air pressure discharged through air port 66 is set such that air port 66 discharges approximately 4.25 to 14.16 liters of air per minute (0.15 to 0.50 cubic feet of air per minute). When only one air hole 66 is used to discharge the process air in each strand 12, the overall use of the process air and the corresponding infrastructure needed to provide the process air is reduced.

In another arrangement shown in Figures 3C and 3D, nozzle body 30 has moved downward relative to strand 12 such that strand 12 angles upward on either side of guide slot 72 and passes through the adhesive chamber 62 at an angle relative to the chamber surface 76. For this purpose, the strand 12 is moved within the adhesive chamber 62 to be closer to the chamber surface 76 at the exit of the adhesive chamber 62 than to the guide groove 72. In this orientation, the space 78a between chamber surface 76 and upper surface 80 of strand 12 are further reduced along the length of adhesive chamber 62 such that an exit gap 78b at the outlet of adhesive chamber 62 is further reduced from space 78a. This reduced exit gap 78b increases the amount of time that

<img file="MX352005B_D0029.tif" />

adhesive 14 is located in adhesive chamber 62, thereby causing increased spread of adhesive 14 around the periphery 20 of strand 12 within adhesive chamber 62 due to spin swelling effects. Again, gap 78a is dimensioned within the range of about 0.0127 cm to about 0.0381 cm (0.005 inches to 0.015 inches).

The adhesive release edge 82a also applies a greater spreading effect on the adhesive 14 as a result of the reduced exit gap 78b at the exit of the adhesive chamber 62. Therefore, the adhesive 14 is forced to spread around the periphery 20 of strand 12 before strand 12 exits adhesive chamber 62 and nozzle body 30. It will be understood that reducing the gap 78a along the length of the adhesive chamber 62 can be achieved in other ways while keeping the strand 12 generally horizontal, including but not limited to tapering the adhesive chamber 62.

The operation of nozzle 19 is shown in Figures 3A-3D and 4. Adhesive passage 58 delivers adhesive 14 through adhesive hole 60 to fill adhesive chamber 62. Adhesive 14 is applied to the upper surface 80 of strand 12 in the embodiment illustrated. Strand 12 then draws adhesive 14 through chamber τ

IMPI, _ MEXICAN INSTITUTE

7 CE ΙΑ PROPERTY 7

IND'JETC'AL of adhesive 62 until strand 12 emerges_e_ from the_ _._ side__________nRear _____ 42 of the nozzle body 30. On this rear side 42, a portion of the adhesive 14 is released from the nozzle body 30 by virtue of the air moving along the rear surface 68 and the adhesive release edge 82a. .

With the release of the nozzle body 30, the adhesive 14 in contact with the strand is struck by additional air discharged from the air hole 66 towards the elastic strand 12. The air causes the adhesive 14, which only partially extends around of the periphery 20 of the strand 12, extends further around the periphery 20 of the strand 12 in order to coat the strand 12 with the adhesive 14. Air discharged from air hole 66 does not blow adhesive 14 out of strand 12 because adhesive 14 is applied to strand 12 and begins to form an adhesive bond with strand 12 before being struck with air. . Additionally, adhesive 14 covers substantially the entire periphery 20 of strand 12 as discussed below rather than wrapping a filament randomly around portions of periphery 20.

Adhesive 14 forms a coating on strand 12 that appears continuous to the naked eye, but it is believed that this coating is not fully continuous throughout

IMPI

8 INSTITUTE MEXICANC

DELA INDUSTRIAL PROPERTY ^ ¿ΖϊϋΞ- ^ · length of strand 12. As described above, adhesive 14 is extruded from adhesive hole 60 into adhesive chamber 62. Stretched elastic strand 12 is received in chamber of adhesive 62 as strand 12 moves in the machine direction. Consequently, adhesive 14 contacts moving strand 12 and rapidly accelerates to be released from nozzle 19 at adhesive release edge 82a. The rapid acceleration of the adhesive causes the adhesive 14 to be applied to the strand 12 in a semi-stable state, such that the amount of adhesive 14 varies along the length of the strand 12. It is believed, more particularly, that adhesive 14 forms localized masses separated by thinner sections that can preferably break apart as adhesive 14 is accelerated by elastic strand 12. As a result, adhesive 14 forms a coating with a plurality of thicker portions 84a, a plurality of thinner portions 84b, and preferably a plurality of void portions 84c where there is no adhesive 14 on the strand 12. The localized masses of adhesive 14 are configured to become discrete points of attachment when elastic strand 12 is secured to one or both of the nonwoven substrates 24a, 24b. Next, the adhesive 14 is hit with air from the air hole 66, which causes the

.M0TICANO INSTITUTE

DI LA HIOPIBOAp INDUSTRIAL extension of adhesive 14 that tends to further spread adhesive 14 in localized masses.

As a result of these operational arms, the resulting coating that forms on strand 12 is believed to include thickness irregularities along the length of strand 12. In this regard, Figures 3B and 3D schematically illustrate that adhesive 14 forms a coating with a plurality of thicker portions 84a, a plurality of thinner portions 84b, and preferably a plurality of void portions 84c where there is no adhesive 14 on the strand 12. These portions 84a, 84b, 84c are shown as an artist's representation and it will be appreciated that the actual appearance and layout of these portions 84a, 84b, 84c may vary in actual use depending on operating parameters such as air pressure. The continuous, visually repeatable appearance of adhesive 14 in strand 12 is desirable in hygiene products, but thickness irregularities in the coating are believed to be formed by adhesive 14 conveniently results in thicker portions 84a that function as dots. discrete bonding units formed along the length of strand 12 when adhered to one or more of substrates 24a, 24b, as described in detail above. More specifically, when it joins between two

<img file="MX352005B_D0030.tif" />

nonwoven substrates 24a, 24b, the heb rw n taj3 ± .j_r. A coated 12 is coated with sufficient adhesive to exhibit a high level of creep resistance and, by virtue of the discrete point of bond effect, also exhibits a high level of retraction force.

In the exemplary coating operation described above in connection with the nozzle 19, the hot melt adhesive 14 that is used to coat the elastic strand 12 has a viscosity in the range of about 3,000 to about 12,000 centipoise and possibly more depending on different operating parameters such as air pressure. The lower viscosity of adhesive 14 leads to improved bonding to a nonwoven substrate and improved penetration into the nonwoven substrate 24a, 24b. Furthermore, the nozzle 19 of the present invention can operate with a wide range of viscosities due to this wide range of potential adhesive viscosity. The lower viscosity of hot melt adhesive 14 also allows adhesive 14 to be applied at a higher temperature to strand 12 and also reduces the overall consumption of adhesive material to coat strand 12. For example, the amount of hot melt adhesive hot 14 applied to strand 12 are in the range of about 25 mg / meter to about 120 mg / meter. &lt;4 ·· higher application temperatures lead to bonding to nonwoven substrate

<img file="MX352005B_D0031.tif" />

form better unions of

24, even with less consumption of adhesive 14. Consequently, nozzle 19 significantly reduces assembly costs of hygiene products by reducing the amount of adhesive 14 and process air consumed and operating with lower adhesive viscosity.

In some alternative embodiments, nozzle 19 includes an adhesive passage 58, multiple air passages 64, and multiple air holes 66 for each strand 12. As shown in Figures 5A and 5B, nozzle 19 includes a first passage of air 64a and a first air hole 66a directed toward one side of strand 12, and nozzle 19 also includes a second air passage 64b and second air hole 66b directed toward the opposite side of strand 12. In an alternative shown in Figure 5A, the first air passage 64a is staggered in the machine direction from the second air passage 64b such that the air flow from each air passage 64a, 64b hits the adhesive 14 on strand 12 in sequence. In another alternative shown in Figure 5B, the first and second air passages 64a, 64b are aligned collinear and within a plane oriented perpendicular to the machine direction such that the air flow from each air passage 64a, 64b hits adhesive 14 on strand 12 at approximately the

<img file="MX352005B_D0032.tif" />

IMPI _cn Mexican wrrruTO

2 OF THE PROPERTY

INDUSTRIAL same location. It will be understood that the number and orientation of the air passages 64 and air holes 66 may be modified in other embodiments without departing from the scope of the invention. Furthermore, it will be understood that each air passage 64a, 64b continues to discharge air at an acute angle to the machine direction to possibly prevent eddy current formation. The first and second air passages 64a, 64b provide redundancy in the event that one of the air passages 64a, 64b becomes blocked, as each air passage 64a, 64b is capable of spreading the adhesive 14 around the strand 12. However, the provision of two or more air passages 64 can result in improved adhesive spread.

Another embodiment of a contact nozzle 110 is illustrated in Figures 6-9. The nozzle 110 of this embodiment includes substantially all of the elements previously described with reference to the embodiment of Figures 2A-4, and these elements are repeated in Figures 6-9 with the same reference numerals as the previous embodiment. These elements and the convenient operation of the nozzle 110 are not repeated in detail, as the following discussion focuses on the differences in this embodiment.

As shown in Figures 6 and 7, the nozzle 110 of this embodiment further includes a pressure control device.

INSTITUTE :

FROM THE PKOFtEOAD WWSTRY The air discharge 190 operatively coupled to the air passage 64 in the nozzle body 30. The air discharge control device 190 intermittently blocks pressurized air discharged from the air port 66. More particularly, the control device Air discharge valve 190 of the illustrated embodiment includes an elongated rotatable member 192 positioned in a side opening 194 through nozzle body 30. Rotating member 192 intermittently blocks air flow through air passage 64. For this purpose, rotating member 192 includes a plurality of flaps 196 that rotate to intermittently block air flow through air passage 64. As shown in Figure 7 by means of arrows 198, rotating member 192 rotates fins 196 in air passage 64 to effectively divide a continuous air flow at air inlet 52 into pulses of air flow. at air hole 66. Consequently, second coating nozzle 110 is operable to discharge pulses of air at device 14 at elastic strand 12. It will be understood that rotary member 192 could be removed from side opening 194 to allow continuous air flow through air passage 64 in other operations. Alternatively, the air discharge control device 190 includes a control solenoid valve that

MEXICAN INSTITUTE Λ

4 OF THE PROPERTY*

INDUSTRIAL selectively blocks the flow of air through the air case 64 to form a continuous flow or a pulsed flow of air.

Rotating member 192 includes side ends 200 engaged with end brackets 202 inserted into opposite sides of side opening 194. End brackets 202 are held in position by locking bolts 204 inserted through the ends. vertical openings 206 in nozzle body 30. More specifically, the locking bolts 204 engage the reduced diameter portions 208 of the end brackets 202 to prevent movement of the end brackets 202 and rotary member 192 in the lateral direction out of the side opening 194. It will be understood that rotary member 192 alternatively includes flow passages intermittently communicating with air passage 64 rather than fins 196 in some embodiments. Furthermore, in other embodiments, the rotatable sino member 92 is replaced by alternate structure operable to control the flow of air through the air passage 64.

Figures 8A and 8B further illustrate the operation of rotating member 192 of the illustrated embodiment. Side opening 194 divides air passage 64 into a portion of overpass 64x leading to air inlet 52 and a „IMPI

5 MEXICAN INSTITUTE

OE INDUSTRIAL PROPERTY underpass portion 64y leading to air hole 66. Each of fins 196 defines an outer surface or region 222 that rotates intermittently in engagement with a wall portion 224 of side opening 194 extending between the upper and lower pass portions 64x, 64y. In the position shown in Figure 8A, region 222 of one of the fins 196 engages the wall portion 224 to effectively block the passage of air from the upper passage portion 64x to the lower passage portion. 64y. When the rotating member 192 is moved to the position shown in Figure 8B, none of the regions 222 of the fins 196 engage the wall portion 224 such that air can flow from the upper passage portion 64x to the 64y underpass portion. Therefore, as the rotating member 192 rotates, the air flow through the air passage 64 and the air port 66 is pulsed.

Rotating member 192 is automatically driven by air flow pressure or is driven separately, such as by means of an external motor (not shown). Therefore, the frequency and length of the air pulses is controlled by any desired setting. For example, the number and shape of fins 196 can be modified on rotating member 192 to modify the pulsed pattern of the

<img file="MX352005B_D0033.tif" />

FROM THE 'NOUSTM PROPERTY to air flow. Air discharge control device 190 is operable to produce any type of pulsed air discharge to meet user requirements. The air flow pulse can be between any pair or more of flow rates, one of which can be zero such as when fins 196 completely block air flow through air passage 64. When the air discharge is pulsed at regular intervals by the discharge control device 190, the adhesive 14 spreads at regular intervals as shown in Figure 9. In this regard, strand 12 includes first portions 212 downstream of nozzle 110 where adhesive 14 extends completely around the periphery 20 of strand 12 and second portions 214 extend completely around the periphery 20 of strand 12 and second portions 214 downstream of nozzle 110 where adhesive 14 remains only partially extended around the periphery 20 of strand 12. In such an operation, the thicker amounts of adhesive 14 remaining on the upper surface 80 of strand 12 in second portions 214 form a discrete point-of-bond effect when strand 12 engages nonwoven substrate 24 on the spool of bond 22. This inconspicuous bonding effect is also enhanced by any thickness irregularity ₅₇ IMPI ^ ^J 'MEXICAN INSTITUTE

OWNERSHIP O? ™ ®®⁶»INDUSTRIAL - · coating of adhesive 14 along the length of strand 12 previously described with reference to the previous embodiment in Figures 2A-4. Also described above, this discrete point of attachment effect is desirable because the elastic strand 12 when attached between two nonwoven substrates 24a, 24b exhibits a high level of retraction force as well as a high level of creep resistance. Although the second portions 214 of strand 12 are shown at particular spacing in Figures 6-9, it will be appreciated that the spacing between these second portions 214 can be increased or decreased in other embodiments. It will also be understood that while the acute angle a is shown as a larger angle in this embodiment than in the embodiment shown in Figures 2A-4, the acute angle ex still remains within the desired range of about 50 degrees to about 80 degrees for the reasons described in detail above.

As in the previously described embodiment, nozzle 110 significantly reduces hygiene product assembly costs by reducing the amount of adhesive 14 consumed and operating with lower adhesive viscosity. Therefore, the nozzle 110 enables more reliable and economical coating of the elastic strands 12.

<img file="MX352005B_D0034.tif" />

An alternative embodiment of an adhesive dispensing system 310 for use in a hygiene product assembly process is shown in Figures 10 and 11. The adhesive dispensing system 310 includes a contact nozzle 312 which includes many of the same elements as the nozzles 19, 110 previously described. For this purpose, the same elements of the preferred embodiments are listed with the same reference numerals in this embodiment. The nozzle 312 again includes an adhesive passageway 58 and an adhesive hole 60 adapted to direct adhesive 14 to fill an adhesive chamber 62 (eg, a slot 62) and be dispensed onto an elastic strand 12 moving in the adhesive chamber 62. The nozzle 312 of this embodiment does not include air passages or air holes formed in the nozzle 312.

Instead, the adhesive dispensing system 310 further includes an air supply line 314. The air supply line 314 includes an air passage (not shown) and terminates in an air hole 316 directed to the upper surface. 80 of strand 12. Therefore, air supply line 314 and air port 316 operate to discharge pressurized air into strand 12, causing adhesive 14 to spread into strand 12 as previously described in other embodiments. As shown in the

IMPI

Mexican Institute of Industrial Property

Figure 11, the air supply line 314 is coupled to a slot 318 in the nozzle 312 such that the air supply line 314 is positioned close to the nozzle 312. In other embodiments, the air supply line 314 it is held close to nozzle 312 by other known mounting devices and methods such as by module 15. In the embodiment of Figures 10 and 11, air hole 316 discharges air along a rear surface 68 of nozzle 312 to aid in the release of adhesive 14 from nozzle 312 at an adhesive release edge 82a.

Consequently, the adhesive dispensing system 310 of this embodiment operates similarly to the nozzles 19, 110 previously described. More specifically, the adhesive dispensing system 310 spreads the adhesive 14 on the elastic strand 12 in a substantially continuous or pulsed manner. Adhesive dispensing system 310 can conveniently coat strand 12 with adhesive 14 with low consumption of adhesive 14 and low adhesive viscosity, if desired. Adhesive dispensing system 310 is positioned to coat strand 12 before strand 12 travels to previously described bond spools 22a, 22b downstream of air supply line 314 to engage one or more non-substrates.

<img file="MX352005B_D0035.tif" />

IMPI

INSTITUTE MEXICANO Di LA MONEDAD INDUSTRIA!

fabrics 24a, 24b to the coated strand 12. Therefore, the adhesive dispensing system 310 improves the hygiene product assembly process.

Still another alternative embodiment of an adhesive dispensing system 410 for use in a hygiene product assembly process is shown in Figure 12. Similar to the previously described adhesive dispensing system 310, this embodiment of the adhesive dispensing system 410 includes a contact nozzle

412 and an air supply line 414 positioned downstream but close to the nozzle 412 in the machine direction. More particularly, air supply line 414 is positioned to be spaced from nozzle 412 such that adhesive 14 partially extends around the periphery 20 of strand 12 before being impacted by pressurized air from the supply line. air 414. In all other respects, adhesive dispensing system 410 operates in the same manner as nozzles 19, 110, and system 310. Previously described. Therefore, the adhesive dispensing system 410 is positioned to coat the elastic strand 12 before the strand 12 travels to the previously described bond spools 22a, 22b downstream of the air supply line 414 to couple one or plus non-woven substrates 24a,

<img file="MX352005B_D0036.tif" />

IMPI

MEXICAN INSTITUTE

D £ INDUSTRIAL PROPERTY

24b to coated strand 12. For all the same reasons described in detail above, the adhesive dispensing system 410 improves the hygiene product assembly process.

An alternative embodiment of an adhesive dispensing system 510 for use in a hygiene product assembly process is shown in Figures 13-15D. The adhesive dispensing system 510 includes a contact nozzle 512 that has a different configuration than nozzles 19, 110, 312, 412 previously described. For example, the contact nozzle 512 of this embodiment does not include an elongated adhesive chamber or separate strand guide as previously shown in the other embodiments.

These differences are highlighted in more detail below.

With particular reference to Figure 13, the nozzle 512 is coating one or more stretched elastic strands 12 with a hot melt adhesive 14 to form an elastic portion of a hygiene product such as a diaper or sanitary napkin. Nozzle 512 applies hot melt adhesive 14 onto elastic strand 12 as elastic strand 12 moves in the machine direction as indicated by arrows 16 in Figure 13. The nozzle 512 then discharges the pressurized air into the hot melt adhesive 14 as shown by laws 18 to cause

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INDUSTRIAL that the hot melt adhesive 14 extends around a periphery 20 of the elastic strand 12. The elastic strand 12 then continues in the machine direction to the first and second tie spools 22a, 22b that engage the first and second nonwoven substrates 24a, 24b such as the top and bottom sheets of a typical diaper to the elastic strand 12 in a sandwich construction. In this regard, the basic operation of the adhesive dispensing system 510 is similar to the general operation of the previously described embodiments.

Nozzle 512 is shown in greater detail in Figures 14A through 15D. The nozzle 512 is a V-notch nozzle 512 that includes a nozzle body 514 having an upper body portion 516 and a lower body portion 518. The nozzle body 514 also includes an upper side 520, a lower side 522 , a front side 524 that extends between the upper and lower sides 520, 522, and a rear side 526 that extends between the upper and lower sides 520, 522. The upper side 520 defines a mounting surface 520 configured to be in contact with the module 15 when the nozzle 512 is coupled to the module 15. The upper body portion 516 is generally longer along the machine direction than the lower body portion 518 from front side 524

<img file="MX352005B_D0037.tif" />

to the rear side 526, thereby giving the nozzle 512 a conical appearance from the upper side 520 to the lower side 522. Therefore, the upper body portion 516 defines the connection portions 528 along the front side. 524 and rear side 526 to align nozzle 512 with module 15. Nozzle 512 is attached to module 15 such that upper side 520 engages module 15 as well understood in US Patent Nos. 6,676,038 and 7,559,487. In some embodiments, the nozzle body 514 can be of a different shape and size, including but not limited to being formed of stacked plates.

Referring to Figure 14A, the nozzle 512 further includes an adhesive inlet 530 and an air inlet 532 positioned along the mounting surface on the upper side 520 of the nozzle body 514. The adhesive inlet 530 is surrounded through a seal groove 534 that receives a seal member 536 between the nozzle 512 and the module 15 previously described. The adhesive inlet 530 is fluidly coupled with a plurality of adhesive passages 538 formed in the nozzle body 514 and extending into the lower body portion 518 of the nozzle body 514. Although two adhesive passages 538 are shown in Figure 14B, more or less adhesive steps

<img file="MX352005B_D0038.tif" />

IMPI

MEXICAN INSTITUTE

OF INDUSTRIAL PROPERTY

538 they may be coupled to the adhesive inlet 530 in other embodiments of the nozzle 512. Each adhesive pass

538 it is spaced from adjacent adhesive passages 538 in a lateral direction transverse to the machine direction.

Each adhesive passage 538 delivers the adhesive 14 from the adhesive inlet 530 to an adhesive hole 540 which communicates with a respective slot in the form of a V-shaped notch 542 (hereinafter V-notch 542) that is it forms near the underside 522 of the nozzle body 514. V-notch 542 inherently operates as a strand guide for nozzle 512 and replaces the strand guide and elongated adhesive chamber of the previous embodiments, although a separate expansion chamber is described in greater detail below. These and other features of the notch between 542 are described in greater detail with reference to Figures 14C, 15A, and 15B below.

In a similar manner, the air inlet 532 is fluidly coupled with a plurality of air passages 544 formed in the nozzle body 514 and extending into the lower body portion 518. Each air passage 544 is positioned proximal to and directly behind the respective adhesive passage 538 within the nozzle body 514. In this regard, each set of an adhesive passage 538 and an air passage 544 coats a strand 12 that passes into

WfflUTO MfcCANO I HEARD LA MOHEDA U

WrxTruAi through nozzle 512. As shown in Figure 15A, it will be understood that at least a lower portion of adhesive passage 538 and air passage 544 are manufactured to be generally parallel to each other, thereby avoiding interference. between passages 538, 544 within nozzle body 514. Each air passage 544 delivers air from air inlet 532 to an air hole 546 directed to adhesive 14 in contact with strand 12. More particularly, hole 546 is positioned adjacent to a rear surface 548, which is part of the rear side

526 of nozzle body 514. As such, air discharged from air passage 544 and air hole 546 is directed along rear surface 548 to act on adhesive 14 as strand 12 exits the V-notch 542.

As shown more clearly in Figures 14C and 15D, the air hole 546 is formed in an intermediate surface 550 extending from the rear surface 548. The thicknesses 550a and 550b of the intermediate surface 550 are on opposite sides of the air hole. Air 546 are minimized to reduce any eddy currents that tend to form adjacent oblique surfaces surrounding air hole 546. The reduction in eddy current along the intermediate surface 550 makes the delivery of air to the strand 12 more laminar.

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Referring to Figures 14B and 14C, the V-notches (eg, grooves 542) of the nozzle body 514 are shown in greater detail. In this regard, each V-notch 542 is defined by two elongated converging surfaces 552a , 552b extending from an access slot 554 defined in the lower side 522 of the nozzle body 514 to an upper edge 556 where the converging surfaces 552a, 552b intersect. Each of the converging surfaces 552a, 552b is generally flat such that the V-notch 542 defines a notch angle β between the converging surfaces 552a, 552b. The notch angle β is illustrated in this exemplary embodiment as being about 90 degrees, although it will be understood that the notch angle β may alternatively range from about 60 degrees to about 90 degrees in other embodiments consistent with the present invention. Access slot 554 communicates with V-notch 542 such that an elastic strand 12 can be inserted upwardly from the bottom of nozzle body 514 into position within V-notch 542. More specifically, elastic strand 12 moves from access slot 554 in engagement with both converging surfaces 552a, 552b adjacent top edge 556. Top edge 556 is preferably formed to be sharp between converging surfaces 552a, 552b, but it will be understood that top edge 556 can define a radius of curvature of up to 0.0254 cm (0.01 inch) without departing from the scope of the invention. As a result of the convergence of the surfaces 552a, 552b and the acute sizing of the upper edge 556, the V-notch 542 defines a strand guide and no additional strand guide element is necessary to accurately position the elastic strand 12 adjacent to the upper edge 556 when elastic strand 12 is positioned within V-notch 542.

Although no additional strand guide element is necessary with the nozzle body 514 to position the elastic strand 12 within the V-notch 542, the nozzle 512 also includes a series of alignment pins 558 that extend downward from the side. front 524 of the nozzle body 514. The alignment pins 558 are therefore located a small distance upstream of the V-notches 542 in the machine direction as previously described. More specifically, each V-notch 542 includes an entry end 560 (Figure ISA) attached in opposite lateral directions by all of the alignment pins 558. When a spring strand 12 moves up through the access slot 554, elastic strand is IMPI

MEXICAN INSTITUTE

OF THE PROPERTY OüAt -— Ι- '' η _or „_ _ Η _ .___. _ „„. „„ .___&gt; ___ ENDUSTRIAL is therefore positioned between these two alignment bolts 558. The alignment bolts 55S function to prevent skipping or unintentional movement of an elastic strand 12 from one V-notch 542 to another V-notch 542 . For example, an elastic strand 12 may include a knot tied between the free ends of two supply spools of elastic strand 12 in order to enable continuous sliding of elastic strand 12 through nozzle 512. When said knot encounters the leading end 560 of the V-notch 542, the larger size of the knot may cause the elastic strand 12 to temporarily jump away from the upper edge 556 of the V-notch 542 into the access slot 554. This jump away from the V-notch 542 may be large enough to move the strand 12 under the access slot 554, which would hypothetically lead to reinserting the strand 12 into an access slot 554 and V-notch 542 different adjacent areas. However, alignment bolts 558 prevent such jumping into an adjacent access slot 554 and V-notch 542 when such an event occurs. Although the alignment pins 558 define a generally cylindrical shape in the illustrated embodiment to reduce any potential frictional contact with the elastic strands 12, it will be understood that they can be used in other

MEXICAN INSTITUTE

OF INDUSTRIAL PROPERTY modalities 558 alignment bolts with different shape and size ^ ño ^. It will also be understood that the alignment pins 558 can be used to keep each elastic strand 12 aligned with the respective V-notch 542 when a conventional lift bar (not shown) is used to temporarily lift each of the elastic strands 12 out of the V-notches 542, such as during interventions in the operation of the nozzle 512.

Additional features of V-notch 542 and nozzle body 514 are shown in Figures 15A and 15B, in which elastic strand 12 and adhesive 14 are not shown to reveal additional elements. For this purpose, the V-notch 542 extends from the inlet end 560 located on the front side 524 of the nozzle body 514 adjacent to the alignment pins 558 to an outlet end 562 located on the rear side 526 of the nozzle body. nozzle 514. As described in greater detail below, the intersection of the V-notch 542 with this rear side 526 and the corresponding air flow on the rear side 526 promote release of the adhesive material from the nozzle 512. Adjacent to the inlet end 560 , the converging surfaces 552a, 552b include the beveled opening portions 564 that enlarge the size of the opening in the V-notch 542, thereby reducing a

<img file="MX352005B_D0039.tif" />

probability that the elastic strand 12, passing a sharp edge of the nozzle body 514. More than halfway along the length of the V-notch 542 (eg, at a location closer to the trailing end 562 than from inlet end 560), V-notch 542 is in fluid communication with passage of adhesive 538 through adhesive hole 540. As shown more clearly in the bottom view of Figure 15B, an expansion chamber 566 is formed by using a ball nose bur to expand the size of the intersection between the V-notch 542 and the adhesive hole 540. . Expansion web 566 includes a rounded profile and extends a small distance above upper edge 566 of V-notch 542 such that adhesive hole 540 defines a substantially flat outlet for adhesive material to flow into. expansion chamber 566. As a result of the spin swelling effects within the larger diameter expansion chamber 566, the adhesive 14 will initially expand within the expansion chamber 566 and discharge from the expansion chamber 566 in contact with the elastic strand 12. and into the V-notch 542. The addition of the expansion chamber 566 enables the use of a smaller diameter 540 adhesive hole, such as 0.0508 cm (0.020 inch) in the exemplary embodiment, which reduces the likelihood of the adhesive material dripping out of the adhesive hole 540 between dispense cycles. In one example, when a ball nose bur is used to form expansion chamber 566, adhesive hole 540 may define a diameter of approximately 0.0508 cm (0.020 inches) while expansion chamber 566 defines a diameter of about 0.635 cm (0.025 inches) to about 0.889 cm (0.035 inches). It will be understood that the expansion chamber 566 may be formed by means of another known method of cutting, drilling, and machining such as festoon cuts in the converging surfaces 552a, 552b in other embodiments to modify the shape or size of the expansion chamber. expansion 566 without departing from the scope of the present invention. It will also be appreciated that the diameter of adhesive hole 540 can be modified to adjust the speed or flow of adhesive 14 exiting expansion chamber 566 and extending around elastic strand 12 in other embodiments consistent with the present invention.

Referring to Figures 15C and 15D, elastic strand 12 and adhesive 14 are shown during operation of nozzle 512. As briefly described above, adhesive 14 is discharged from adhesive passage 538 through adhesive hole. 540 and at

<img file="MX352005B_D0040.tif" />

inside the upper expansion chamber 556 of the V-notch 542.

566 adjacent to edge

The expansion chamber

566 it is substantially filled with adhesive 14 such that adhesive 14 flows out of expansion chamber 566 and into contact with elastic strand 12 past expansion chamber 566. More specifically, adhesive 14 is applied to an upper surface 80 of elastic strand 12 in expansion chamber 566, and strand 12 effectively splits at least a portion of adhesive 14 that flows out of expansion chamber 566 to forcing adhesive 14 to move along converging surfaces 552a, 552b of V-notch 542 and begin to spread around strand 12. The exemplary sharp sizing of top edge 556 described in detail above ensures that strand 12 remains generally centered with respect to expansion chamber 566, thereby ensuring splitting and spreading of the adhesive 14 it includes out of expansion chamber 566. Because elastic strand 12 passes expansion chamber 566 at a higher rate than adhesive 14 is delivered to expansion chamber 566, strand 12 effectively draws adhesive 14 out of expansion chamber 566 at a rate. semi-stable state and the adhesive 14 has no opportunity to dislodge the elastic strand 12. Immediately after leaving the

IMPI

INSTITUTE MEXICANO expansion chamber 566, the adhesive 14 along the upper surface 80 of the elastic strand 12 moves mechanically as the adhesive 14 is pressed between the converging surfaces 552a, 552b of the V-notch 542 downstream of the expansion chamber. expansion 566. This mechanical movement causes the adhesive 14 to spread or wipe around the periphery 20 of the strand 12 (see, for example, Figure 14C) as the strand 12 moves toward the exit end 562 of the V-notch 542. The The amount of spreading or initial cleaning of the adhesive 14 around the periphery 20 can be adjusted by adjusting the notch angle β within the desired range of about 60 degrees to about 90 degrees. Consequently, when the elastic strand 12 reaches the exit end 562 of the V-notch 542, the adhesive 14 is already beginning to spread and move around the periphery 20 of the strand 12.

As shown in Figure 15D (and also Figure 14C), the rear surface 548 of the nozzle body 514 also intersects a lower rear surface 570 at an elongated edge 572. The trailing end 562 of the V-notch 542 intersects this lower rear surface 570 such that upper edge 556 intersects elongated edge 572 at an adhesive release edge 572a. The upper edge 556 and the

ΙΜΡΙ®3 τ / Ι INTOTUTO MEXICANO / 4 OF THE PROPERTY

INDUSTRIAL --- back surface 548 defines an interior angle a at the adhesive release edge 572a. The interior angle a is an acute angle such that the adhesive release edge 572a promotes the acute release of the adhesive 14 on the strand 12 from the nozzle body 514. The interior angle a is measured in an upstream direction along the along the machine direction from the adhesive release edge 572a. For this purpose, the interior angle a is defined by the nozzle body 514 at the adhesive release edge 572a. In the illustrated embodiment, the acute angle from the machine direction can be in the range of about 50 degrees to about 80 degrees. As the acute angle a becomes smaller within this range, the airflow from air hole 546 becomes more parallel to the movement of strand 12 along the machine direction, which enables use higher air pressures than the air flow to spread the adhesive 14 further without blowing the adhesive 14 out of the strand 12. The adhesive release edge 572a therefore applies a similar cleaning or spreading effect on the adhesive 14, the converging surfaces 552a, 552b of the V-notch 542. Similarly, the acute angle a is also defined between the surface mounting on the upper side

520 nozzle body 514 and a longitudinal axis 574

5

<img file="MX352005B_D0041.tif" />

defined through air hole 546 and dTtavé^,S "^,tle! "Crl · minus a portion of air passage 544, as shown in

Figure 15A.

Air discharged from air hole 546 along rear surface 548 as shown by arrows 18 is also one with release of adhesive 14 from nozzle body 514 at adhesive release edge 572a. Air traveling along back surface 548 strikes upper surface 80 of strand 12 at a non-perpendicular angle in such a way that it is believed to prevent the formation of any eddy currents around adhesive release edge 572a . More specifically, the air strikes the upper surface 80 of strand 12 at the acute angle a described above. Thus, the adhesive 14 remains attached to the moving strand 12 downstream of the adhesive release edge 572a rather than accumulating on the nozzle body 514. As a result, the risk of the adhesive is substantially reduced or eliminated. 14 builds up in nozzle body 514, char, and block air hole 546. Air discharged from air hole 546 also continues to spread adhesive 14 around the periphery 20 of strand 12 to thereby form thicknesses of adhesive 14 that vary along the length of the strand.

<img file="MX352005B_D0042.tif" />

<img file="MX352005B_D0043.tif" />

6 &gt; STnw_0MEXlCAN0OF INDUSTRIAL PROPERTY

12, as described in greater detail below.

With the release of the nozzle body 514, the adhesive 14 in contact with the strand 12 is struck by additional air discharged from the air hole 546 towards the elastic strand 12. The air causes the adhesive 14, which extends only partially around the periphery 20 of the strand 12, extends further around the periphery 20 of the strand 12 in order to coat the strand 12 with the adhesive 14. The mechanical movement of the adhesive with converging surfaces 552a, 552b immediately prior to this air impact is believed to further enhance the spreading effects caused by air. Air discharged from air hole 546 does not blow adhesive 14 out of strand 12 because adhesive 14 is applied to strand 12 and begins to form an adhesive bond with strand 12 within V-notch 542 before being hit with the air. As a result, adhesive 14 covers substantially the entire periphery 20 of strand 12 as explained above.

Adhesive 14 forms a coating on strand 12 that appears continuous to the naked eye, but this coating is not believed to be fully continuous along the length of strand 12. As previously described, adhesive 14 is extruded from the adhesive hole 540 al

INSTITUTE MEXICANO DE LA INDUSTRIAL PROPERTY inside expansion chamber 566 and then onto 1st strand 12. Consequently, adhesive 14 makes contact with strand 12 in motion and rapidly accelerates, causing adhesive 14 to be applied to the strand 12 in a semi-stable state such that the amount of adhesive 14 varies along the length of strand 12. More particularly, the adhesive 14 is believed to form localized masses of thicker obsessions separated by thinner sections as the adhesive 14 is accelerated by the elastic strand 12. These localized masses of adhesive 14 are configured to become discrete points of attachment when the bond is secured. elastic strand 12 to nonwoven substrates. Next, the adhesive 14 is blown with air from the air hole 546, which causes the spread of the adhesive 14 which tends to further spread the adhesive 14 into localized masses.

As a result of these operational steps, the resulting coating formed on strand 12 is believed to include thickness irregularities along the length of strand 12. In this regard, Figures 15C and 15D schematically illustrate that adhesive 14 forms a coating with a plurality of thicker portions 84a, a plurality of thinner portions 84b, and preferably a plurality of empty portions 84c where

<img file="MX352005B_D0044.tif" />

ΙΜΡΪ ^

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL there is no adhesive 14 on strand 12. These portions 84a,

84b, 84c are shown as an artist's representation and it will be appreciated that the actual appearance and layout of these portions 84a, 84b, 84c may vary in actual use depending on operating parameters such as air pressure. The continuous, visually repeatable appearance of adhesive 14 on strand 12 is desirable in hygiene products, but coating irregularities believed to be formed by adhesive 14 conveniently result in thicker portions 84a that function as discrete dots of bonds formed along the length of strand 12 when adhered to one or more of substrates 24a, 24b, as described in detail above. More specifically, when bonded between two nonwoven substrates 24a, 24b, the coated elastic strand 12 is coated with sufficient adhesive 14 to exhibit a high level of creep resistance and, by virtue of the discrete point bond effect, also exhibits a high level of retraction force.

Consequently, the adhesive dispensing system 510 of this embodiment operates in a general manner similar to the nozzles 19, 110, 312, 412 previously described. More specifically, the adhesive dispensing system 510 applies the adhesive 14 by coating of

<img file="MX352005B_D0045.tif" />

9

IMPI

INSTITUTE MEXICANO Di LA PROPIEDAD INDUSTRIAL contact of adhesive 14 on elastic strand 12 movement and then spreads adhesive 14 using air flow after adhesive 14 is in contact with strand 12. Adhesive dispensing system 510 can coat conveniently a strand 12 with adhesive 14 with low consumption of adhesive 14 and low adhesive viscosity, if desired. It will be understood that the adhesive dispensing system 510 of this embodiment is operable to coat stretched elastic strands 12 that move faster and more closely spaced than with conventional non-contact nozzle designs because the adhesive 14 is placed in direct contact. with strands 12 and because pressurized airflow does not require significant spacing to avoid airflow interference from one strand 12 to another strand 12. Therefore, the 510 adhesive dispensing system improves the hygiene product assembly process.

The present invention also includes a method of contact coating a stretched elastic strand with an adhesive, wherein the strand includes a periphery with an upper surface. The method includes moving the strand in the machine direction with respect to a contact nozzle, discharging the adhesive from the contact nozzle onto the upper surface of the strand as

<img file="MX352005B_D0046.tif" />

IMPI

RO πηπτυτο Mexican ^or OS THE CURRENCY

INDUSTRIAL strand is moving, and discharging pressurized air into the adhesive over the moving strand. The air causes the adhesive to spread around the periphery of the strand to thereby coat the strand with the adhesive. The air also assists with the release of adhesive from the contact tip and cleanses the contact tip of accumulated adhesive that would eventually char and adversely affect the operation of the contact tip. Thus, the strand coating method enables coating of a strand without the need to produce a spiral pattern or other pattern with process air impacting a dispensed adhesive strand during flight.

The discharge of the air is controlled to have different air flow characteristics depending on the type of coating desired on the strand. In one example, air is continuously discharged into the adhesive in contact with the strand as the strand moves to cause generally continuous spread of the adhesive around the strand. In another example, air is discharged in a non-continuous manner such as periodic pulses on the adhesive in contact with the strand as the strand moves to cause a non-continuous (eg, pulsed) spread of the adhesive around the strand. strand. The air is discharged at an acute angle to the direction of the machine,

<img file="MX352005B_D0047.tif" />

measured between the direction of the air discharge and the elastic strand upstream of the air. This acute angle can also be measured between a longitudinal axis through an adhesive hole and a mounting surface of the contact nozzle, the mounting surface configured for is coupled to a module and including an adhesive inlet to receive the sticker from the module. In the illustrated embodiment, the acute angle from the machine direction can be in the range of about 50 degrees to about 80 degrees, which is believed to prevent the formation of any eddy currents in the air that could cause the adhesive will blow off the strand.

In an alternative, multiple streams of air are discharged into the adhesive on the strand to cause the adhesive to spread around opposite sides of the periphery of the strand. The multiple streams of air are staggered in the machine direction such that the multiple streams of air hit the strand at different locations along the machine direction. Alternatively, the multiple streams of air are nested in a plane perpendicular to the machine direction such that the multiple streams of air strike the strand in approximately the same location along the way.

<img file="MX352005B_D0048.tif" />

along the machine direction. It will be understood that each of the multiple streams of air in those modes continues to be discharged at an acute angle to the direction of the machine.

In some embodiments, moving the strand includes moving the strand through a strand guide and through an elongated adhesive chamber. In those embodiments, dispensing the adhesive onto the top surface of the strand further includes filling the adhesive chamber of the contact nozzle with the adhesive as the strand moves through the adhesive chamber. The strand is positioned within the adhesive chamber to reinforce the initial spread of adhesive around the periphery of the strand within the adhesive chamber. Furthermore, the movement of the strand draws the adhesive out of the adhesive chamber. The strand is moving at a speed greater than the speed at which the adhesive enters the adhesive chamber such that a minimal amount of adhesive is applied to the strand. In some arrangements, the strand is angled relative to the adhesive chamber or the adhesive chamber is tapered such that the adhesive sits in the adhesive chamber for a longer period of time, thereby causing increased spreading of adhesive around the strand. In these arrangements, the strand effectively moves laterally

INSTITUTE MEXICO DE LAFRCTKOAD imwruAi into the adhesive chamber as the strand travels along the length of the adhesive chamber, which will further promote increased adhesive spread around the strand. In other embodiments, the adhesive is dispensed onto the upper surface of the strand from an adhesive hole in communication with a V-notch through which the strand moves. In these embodiments, the surfaces defining the V-groove mechanically move the adhesive and spread the adhesive around the periphery of the strand. As a result of adhesive spreading both within the adhesive chamber or V-notch and caused by air flow directed at an acute angle to the elastic strand (eg, angled by about 50 degrees to about 80 degrees) Outside of the adhesive chamber or V-notch, the adhesive coating on the strand is believed to include random thickness irregularities that function as discrete points of bond that form along the length of the strand.

In one example, the method of coating a strand is used during the assembly process for a hygiene product. In those embodiments, the method further includes bonding the stretched elastic strand between two layers of nonwoven substrates after the hot melt adhesive has spread around the periphery of the strand for 't ^ —ιι »μ i int

<img file="MX352005B_D0049.tif" />

form at least a portion of the hygienic product. Depending on the needs of the user, the hot melt adhesive is spread using air flow in a continuous manner or in a pulsed manner. The method therefore conveniently coats a strand with adhesive with low adhesive consumption and low adhesive viscosity. As a result, the method of the present invention improves the hygiene product assembly process.

In another example, the method of coating one strand is used to coat multiple stretched elastic strands simultaneously. To this end, the contact nozzle may include published patterning that enables the discharge of adhesive and pressurized air over each of the plurality of strands. The coated elastic strands can then be used to assemble one or more hygiene products. It will be understood that the method according to any of the modalities described above can be used to coat multiple strands.

While the present invention has been illustrated by description of specific embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or limit in any way the scope of the claims appended to said detail. The different features that are discussed in₈₅ IMPI

INSTITUTE MEXICANO Oí LA PROPIEDAD industrial ------ this document can be used alone or in any r «se.w.sr» »» · ** · ιιβββββ · »- combination. Additional advantages and modifications will readily appear to those of skill in the art. For example, the slots shown in the nozzle bodies of the different embodiments can be modified in shape, size, and configuration without departing from the scope of the present invention. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and methods, and illustrative examples that are shown and described. Accordingly, deviations from such details can be made without departing from the scope or spirit of the general inventive concept.

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INDUSTRIAL = 1 ---^r