Absorbent article and absorbent core forming channels when wet

Background of the Invention

Absorbent items for personal hygiene, such as disposable baby diapers, baby diaper pants and hygiene products for adults, are designed to absorb body secretions, in particular large amounts of urine. The hygiene articles concerned contain several layers having different functions, for example the top layer, the bottom layer and the absorbent body placed between them, as well as other layers.

Absorbent insert usually has the function of absorbing and retaining secretions for a longer period of time, allows minimizing re-wetting, so as to provide the user with a feeling of dryness and prevents soiling of clothing or bedding. Most absorbent hygiene articles on the market today contain absorbent material in the form of a mixture of comminuted pulp with superabsorbent polymers (SAP) in the form of particles, also called absorbent gelling materials (AGM): see for example, US patent 5,151,092 (Buell). Absorbent products with a pad consisting mainly of SAP polymers as absorbent material have also been proposed (so-called "pads without aerated fiber") (see for example. patents WO2008 / 155699 (Hundorf), WO95 / 11652 (Tanzer), WO2012 / 052172 (Van Malderen)). In addition, proposals were made for absorbent pads with slits or grooves that were typically intended to increase their ability to collect liquid or act as a folding guide. WO2009 / 047596 (Wright) discloses an absorbent article with an absorbent core with slits.

Patent US2004 / 220541 (Suzuki) discloses an absorbent pad with concave and convex parts on its surface and spontaneously

EP 2 813 201 showing a three-dimensional structure in which a concave-convex structure is formed. Patent US2007 / 244455 (Hansson) discloses an absorbent body in an absorbent article provided with at least two folding members extending substantially in a longitudinal direction in the perineum and sharing at least part of the perineum of the absorbent body in the middle and two side parts as seen in lateral direction. At least two tensile elastic crotch elements are arranged in the crotch portion of the article and are attached to the absorbent body and / or the inner or outer covering.

EP1,447,066A1 discloses diapers containing a pad with a high content of absorbent polymeric material that is immobilized when wet. In one embodiment, an absorbent core comprising two substrates surrounding the absorbent material immobilized by the thermoplastic material is disclosed. The cartridge contains areas of joints that are areas of direct contact between the thermoplastic material and the substrate material. These connection areas are essentially free of absorbent material. The connection areas are preferably round. GB2.283.689 discloses an absorbent article containing superabsorbent material disposed in a separate area.

It is also known to provide a sublayer, typically a nonwoven, between the top layer and the absorbent body. These sublayers are intended for rapid collection and / or distribution of liquid from the top layer into the cartridge. These sub-layers are sometimes referred to as "moisture wicking layer", "swelling layer" "collecting layer" or "spreading layer".

Products having only one such sublayer are known. A single sublayer is disclosed, for example, in WO94 / 23761 (Payne), which discloses a collecting layer comprising a hydrophilic fibrous material and a storage layer comprising a mixture of hydrophilic fibrous material and separate particles of gelling absorbent material. The collecting layer has a collection zone towards the front of the product with a relatively lower average density and a relatively lower average basis weight than the distribution zone towards the rear of the product. Another example of a sublayer having one layer can be found in publications US5.486.166 and US5.490.846 (Bishop).

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US2008 / 0312621 and US2008 / 0312622 (Hundorf) describe a disposable absorbent article comprising a base comprising a top layer and a bottom layer, essentially a cellulose-free absorbent core disposed between the top layer and the bottom layer and having a side facing the user oriented towards the user, when the product is worn and the opposite side facing the clothing, A "fluid storage system" containing chemically crosslinked cellulose fibers disposed between the liquid-permeable top layer and the side of the absorbent body facing the user. The fluid collection system may also include an upper collection layer made of latex bonded non-woven fabric.

Patent WO2012 / 170778 (Rosati et al., See also WO2012 / 170779,

WO2012 / 170781 and WO2012 / 1708008) contains a description of absorbent structures comprising a superabsorbent polymer, optionally cellulosic material, and at least one pair of substantially elongated channels. The insert cover can be glued between the channels to connect them. The channel connections can be solid so that their integrity is at least partly maintained in both dry and wet condition. As the liquid absorbs and swells, the absorbent structure takes on a three-dimensional shape and the channels become visible. The use of channels ensures better fit and / or fluid accumulation / transfer as well as better functioning when using the absorbent structure.

In a first aspect of the invention, the inventors have now discovered that the creation of three-dimensional channels in a wet absorbent body can help create three-dimensional grooves in a fibrous structure sandwiched between the top layer and the top side of the absorbent body. The fibrous structure may, for example, be a collection and / or distribution layer. Grooves in the fibrous layer may provide benefits in terms of fluid collection and distribution. In a second aspect, the invention relates to an absorbent core that can be used in an article of the present invention and which includes a cartridge sheath connection that opens gradually as the absorbent core swells to provide additional space for the swellable absorbent material.

Summary description of the invention

The invention relates to an absorbent article for personal hygiene as defined in the claims. The absorbent article has a longitudinal axis and comprises

EP 2 813 201 a liquid-permeable top layer, a liquid-impermeable bottom layer and an absorbent body between the top layer and the bottom layer. The absorbent body comprises a body of the body formed of materials selected from paper, tissue paper, foil, fabrics, nonwovens or laminates of any of these materials, surrounding the absorbent material and comprising a top side and a bottom side. The absorbent material contains a super absorbent polymer. The absorbent body comprises at least a pair of areas substantially free of absorbent material. The top side of the insert shell is attached to the underside of the insert shell through areas substantially free of absorbent material, such that when the absorbent material swells, the insert shell forms a pair of channels that can be used to distribute liquid secretions along the length of the channel. The absorbent article further comprises a fibrous layer between the absorbent body and the top layer, which is at least partially bonded to the top or bottom side of the sheath of the body in areas substantially free of absorbent material. The formation of channels in the absorbent body as the absorbent material swells creates corresponding grooves in the fibrous layer.

Brief description of the figures

Fig. 1 is a top view of an embodiment of the present invention in the form of a diaper before use with some layers removed;

Fig. 2 is a cross-sectional view of the embodiment of Fig. 1 at the crotch point (C);

Fig. 3 is a cross-sectional view of the embodiment of Fig. 1 at the crotch point (C) made at the same point as in Fig. 2, where the channels and the grooves have been formed by filling the diaper with liquid;

Fig. 4 is a top view of the absorbent body of Fig. 1 with a partially removed top layer;

Fig. 5 is a cross-sectional view of the insert of Fig. 4 at the crotch point; Fig. 6 shows a longitudinal section of the absorbent body of Fig. 4;

Fig. 7 is a simplified top view of an embodiment of the connection area between the cartridge cover and the fiber layer covering substantially all of the underneath surface of the fiber layer;

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Fig. 8 shows an alternative connection area comprising two longitudinally extending areas with an unbonded zone in the central region of the fiber layer;

Fig. 9 is an alternative view in which the fibrous layer is bonded to the sheath of the pad in an area substantially corresponding to areas substantially free of absorbent material;

Fig. 10 shows an alternative view in which the fibrous layer interface area is smaller than the fibrous layer;

Fig. 11 shows an alternative connection area in which the fibrous layer is bonded to the cartridge cover along transverse stripes;

Fig. 12 shows the embodiment as in Fig. 7 and further shows the possible application pattern for gluing the top layer to the underlying layer;

Fig. 13 shows the embodiment as in Fig. 8 and further shows the possible application pattern for gluing the top layer to the underlying layer;

Fig. 14 is a schematic cross-sectional view of an exemplary dry product having a collection layer in addition to the fibrous layer;

Fig. 15 shows a schematic cross-section corresponding to Fig. 14 when the product is wet and the channels have been formed in the insert and grooves in other layers of the absorbent article.

Fig. 16 is a schematic cross-section corresponding to the previous Figures 14-15, where the connections of the cartridge housing have delaminated.

Detailed description of the invention

Admission

As used herein, the term "absorbent article for personal hygiene" refers to disposable items such as baby diapers, baby diaper pants or products for adults suffering from urinary incontinence, sanitary napkins and the like that are placed on the user's body. or in its vicinity to absorb and retain various body secretions excreted by the body. Absorbent articles according to the present invention will be described in more detail in the following description and in the figures in the form of a diaper fastened with a tape. It should not be however

EP 2 813 201 treat nothing herein as limiting the scope of the claims, unless expressly stated otherwise.

The term "nonwoven" as used herein means a layer, web or mat produced with directionally or accidentally oriented fibers, welded by friction and / or cohesion and / or gluing, with the exception of paper and products that are woven, knitted, tufted, stapled and they have girdings or fibers, or are wet-felted regardless of whether they are stapled or not. The fibers may be of natural origin or man-made, and may be stapled or contain continuous filaments or fibers formed during manufacture. Commercially available fibers have a diameter ranging from below about 0.001 mm to above about 0.2 mm and come in several different forms: short fibers (known as chopped or crushed), continuous monofilaments (filaments or monofilaments), untwisted bundles of continuous filaments (pulled out) and twisted tufts of continuous filaments (yarn). Nonwovens can be formed using a variety of processes such as meltblowing, molding, solvent spinning, electrostatic spinning, carding and pneumatic stacking. The basis weight of the nonwovens is usually expressed in grams per square meter (g / m2² or gsm).

The term "connected", "bonded" or "attached" as used herein includes configurations in which an element is directly attached to another element by attaching the element directly to another element, and configurations in which an element is indirectly attached to another element by fastening this element to the element or intermediate elements, which in turn are attached to another element.

The terms "contain", "containing" and "contains" are open terms, each of which defines the presence of the following elements, e.g. component, but it does not exclude the presence of other functions, e.g. elements, steps, ingredients known in the art or disclosed herein. These verb-based "include" terms should be understood to include the narrower terms "consisting of" which exclude any element, stage or indefinite element and "consisting essentially of" which restricts the scope of the element to specific materials or stages and those which have no significant effect on the way the element works.

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No preferred or illustrative embodiments of the invention set out below limit the scope of the claims, unless expressly so stated. The words "typically", "normal", "preferably", etc. also specify elements that do not limit the scope of the claims, unless expressly so stated.

General description of the absorbent article

An exemplary absorbent article according to the invention in the form of a baby diaper 20 is shown in Figs. 1-3. Fig. 1 is a plan view of the exemplary diaper 20, in an unfolded state, with cut-out fragments of the structure for a clearer representation of the diaper structure 20. The diaper 20 has been shown for illustrative purposes only, since the invention can be used to produce a wide range of diapers or other articles lymph.

The absorbent article has a liquid-permeable cover layer

24, a liquid-impermeable backing layer 25 and an absorbent body 28 between the top layer 24 and the bottom layer 25 and the fibrous layer 54.

FIG. 1 also shows other typical components of a diaper fastened with a tape, such as a fastening system comprising pleats with glue 42 attached along the back edge of the product and cooperating with the fastening zone 44 at the front of the product, cuffs protecting the legs 34 and elastic sealing cuffs 32 connected to the base of the absorbent product, typically through top layer and / or bottom layer and substantially in plane with the diaper base. The absorbent article may also contain other typical elements that are not represented, such as a back elastic waist area, an front elastic waist area, a transverse protective cuff (transverse protective cuffs), a cosmetic emulsion, etc.

The absorbent article 20 comprises a front edge 10, a rear edge 12 and two side (longitudinal edges) 13, 14. The front edge 10 is the edge of the article intended to be placed towards the front side of the user after the article has been placed, and the rear edge 12 is the edge on the opposite side of the article. The absorbent article may be hypothetically divided by means of a longitudinal axis 80 extending from the front to the rear edge of the article and dividing the product into two substantially symmetrical halves relative to this axis, when the product is laid flat and viewed from above as shown in Fig. 1. Length

Product L can be measured along the longitudinal axis 80, from the front edge 10 to the rear edge 12. The product has a crotch point C defined herein as a point located on the longitudinal axis two fifths (2/5) L away from the front edge 10 of product 20. The width of the article, when used as diapers at the crotch point, may in particular be from mm to 300 mm, or from 80 mm to 250 mm. For products for adults suffering from incontinence, the width may be up to

450 mm.

The crotch area may be defined as the diaper area longitudinally centered at the crotch point C and extending toward the front and back of the absorbent article by a fifth of the length (L / 5) in each direction. The front area and back area can be defined as the remaining parts of the diaper positioned towards the front and rear edges of the article, respectively.

The cover layer 24, the bottom layer 25, the absorbent body 28 and other components of the article can be combined in various known configurations, in particular using gluing or hot stamping. Exemplary diaper configurations are generally described in patents US3.860.003, US5.221.274, US5.554.145, US5.569.234, US5.580.411 and US6.004.306. Preferably, the absorbent article is thin for the invention. The thickness at the crotch point C of the article may be, for example, from 3.0 mm to 12.0 mm, in particular from 4.0 mm to 10.0 mm, as measured in the absorbent article thickness test described herein.

An example absorbent body 28, shown in Fig. 4, includes the absorbent material and a liner surrounding the absorbent material. The cartridge housing may typically comprise two substrates 16 and 16 'on the top and bottom sides of the cartridge, respectively. The absorbent body further comprises one or more area (s) substantially free of absorbent material 26 surrounded by absorbent material (in the plane formed by the absorbent material). The top side of the insert shell is attached to the underside of the insert shell through one or more substantially free area (s) of absorbent material 26 by one or more connection (s) of the insert shell 27 so that when the absorbent material swells, the absorbent body forms one or more channel (s) 26 'in the area (s) 26 along the connection of the cartridge housing 27. These channels can be used to distribute liquid secretions along the length of the channel.

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The absorbent article further comprises a fibrous layer 54 between the cover layer and the absorbent body. The fibrous layer is at least partially bonded to the top side of the liner shell in area (s) 26 substantially free of absorbent material. The connection of the fibrous layer at the top side of the insert shell in the area (s) 26 substantially free of absorbent material causes the formation of one or more respective grooves 29 in the fibrous layer as schematically shown in Fig. 3 and Fig. 14-15. These and other product components will now be discussed in more detail.

Top layer 24

The cover layer 24 is a part of the absorbent article which is in direct contact with the user's skin. The top layer 24 can be combined with the bottom layer 25, the insert 28 and / or any other layers as is known in the art. Typically, the top layer 24 and the bottom layer 25 can be connected directly to each other on or near the periphery of the article and are connected indirectly to each other at other places by directly connecting them to one or more other elements of the article 20. The top layer may be attached to the underlying layer, which may be a fibrous layer 54 or other layer, such as collecting layer 52, by all conventional means, in particular by gluing, mechanical joining, hot joining or a combination thereof. The top layer may in particular be attached directly or indirectly to the fibrous layer 54 in the area where grooves of the fibrous layer are formed, as exemplified in Fig. 3 and 14. This can provide or support the formation of auxiliary grooves on the surface of the product.

Preferably, the top layer 24 is flexible, soft to the touch and does not cause irritation to the wearer's skin. In addition, at least part of the cover layer 24 is liquid permeable, allowing fluids to easily penetrate through its thickness. A preferred top layer can be made of a wide range of materials such as porous foams, crosslinked foams, perforated plastic nonwovens or woven or nonwovens made of natural fibers (e.g. wood or cotton fibers), synthetic or filamentary fibers (e.g. polyester fibers) or polypropylene or PE / PP biocomponent fibers or mixtures thereof), or a combination of natural and synthetic fibers. If the top layer contains fibers, fibers

EP 2 813 201 can be formed from a mass, carded, wet-laid, pneumo-thermally blown, hydrodynamically braided or processed in another way known in the art, in particular non-woven fabric formed from a PP mass. A preferred top layer comprising a long polypropylene mesh is manufactured by Veratec Inc., Division of International Paper Company, in Walpole, MA under the designation P-8.

Preferred molded foil surface layers are also disclosed in US Patent 3,929,135, US 4,324,246, US 4,342,314, US 4,463,045 and US 5,006.394. Other preferred cover layers may be made according to US Patents 4,609,518 and 4,629,643 to Curro et al. Such molded films are manufactured by Procter & Gamble Company, Cincinnati, Ohio as "DRI-WEAVE" and by Tredegar Corporation based in Richmond, Virginia as "CLIFF-T".

Each part of the cover layer 24 may be covered with an emulsion known in the art. Examples of suitable emulsions include those disclosed in US 5,607,760, US 5,609,587, US 5,635, US 5,643,588, US 5,968,025 and US 6,716,411. The top layer 24 may also contain or be treated with anti-bacterial agents, some examples of which are disclosed in International Patent Application WO 95/24173. In addition, the top layer 24, bottom layer 25, or any part of the top layer or bottom layer may be embossed and / or matte finished to provide a more fabric-like appearance.

The top layer 24 may include one or more openings to facilitate passage of bodily secretions such as urine and / or faeces (solid, semi-solid or liquid) through it. The size of at least the main opening may be important in achieving the desired result in terms of faecal retention. If the main hole is too small, droppings will not be able to pass through the hole, due to insufficient alignment of the droppings source with the position of the hole or due to fecal masses having a diameter larger than the hole. If the opening is too large, the surface of the skin will increase, which may be contaminated as a result of "wetting" the product. Typically, the total size of the opening on the surface of the diapers is between about 10 cm² and about 50 cm², in particular between about 15 cm² and 35 cm². Examples of a perforated cover layer are disclosed in US Patent 6,632,054 to BBA

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NONWOVENS SIMPSONVILLE. WO 2011/163582 also discloses a preferred colored top layer with a basis weight in the range from 12 to 18 gsm and having a plurality of connection points. The surface area of ​​each connection point is in the range of 2 mm² up to 5 mm², and the total area of ​​the connection points is in the range of 10 to 25% of the total surface area of ​​the top layer.

The basis weight of typical diaper top layers is in the range of from about 10 to about 28 gsm, in particular in the range between about 12 to about 18 gsm, but other weights are possible.

Bottom layer 25

The backsheet 25 is generally the part of the absorbent article 20 that forms the greater part of the outer surface of the user-worn article. The bottom layer is directed towards the underside of the absorbent body and protects against soiling with secretions absorbed and retained in the product, such as bedding and underwear. The bottom layer 25 is usually liquid-impermeable (e.g. urine). For example, the bottom layer may be or include a thin plastic film, such as a thermoplastic film with a thickness of from about 0.012 mm to about 0.051 mm. Exemplary backing films include those produced by the company

Tredegar Corporation, based in Richmond, Virginia, and sold under the trade name CPC2 film. Other preferred materials for the backsheet may include breathable materials that allow steam to escape from the diaper 20 while preventing bodily secretions from entering through the backsheet 25. Exemplary breathable materials may include materials such as fabrics, nonwovens, composite materials such as film coated nonwovens, microporous films, such as those manufactured by Mitsui Toatsu Co., Japan and offered under the designation ESPOIR NO, and by the Tredegar Corporation of Richmond, VA and sold under the designation EXAIRE and monolithic films, such as those produced by Clopay Corporation,

Cincinnati, OH under the name HYTREL blend P18-3097. Some breathable composite materials are described in more detail in PCT Application No. WO 95/16746 published June 22, 1995 on behalf of EI DuPont; US 5,938,648 to LaVon et al., US 4,681,793 to Linman et al.,

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US 5,865,823 to Curro; and US 5,571,096 to Dobrin et al., US 6,946,585B2 to London Brown.

The bottom layer 25 may be connected to the top layer 24, the absorbent body 28 or any other diaper element 20 by any suitable connecting element known in the art. Preferred connecting elements have been described above with respect to the elements connecting the cover layer 24 to other elements of the product 20. For example, bonding methods include a uniform, continuous adhesive layer, an adhesive layer of a particular pattern, or a system of separate lines, spirals, or dots of adhesive. Preferred joining methods include an open fiber network pattern as disclosed in US 4,573.986. Other preferred joining methods include several adhesive fiber lines that are swirled in a spiral pattern, as illustrated by the apparatus and methods described in US Patent 3,911,173, US 4,785,996; and US 4,842,666. Adhesives found to be satisfactory are produced by H. B. Fuller Company, St. Paul, Minnesota and marketed as HL-1620 and HL 1358-XZP. Alternatively, the connecting member may include thermal bonds, pressure bonds, ultrasonic bonds, dynamic mechanical connections or any other suitable connecting elements or combinations of these connecting elements known in the art.

Absorbent body 28

The absorbent body is typically a component of the article having the highest capacity. The absorbent core comprises a core covering, the absorbent material and, optionally, an adhesive surrounded by a core covering. The absorbent material comprises a super absorbent polymer (hereinafter referred to as "SAP"), in particular the absorbent material of the present invention may contain absorbent material with a high amount of super absorbent polymers surrounded by a sheath of the insert. The SAP content may be at least 40% and more (in particular at least 60%, or at least 80%) by weight of the absorbent material contained in the insert shell. The absorbent body may not contain aerated fiber material. The insert cover is not considered as absorbent material for purposes related to assessing the percentage of SAP material in the absorbent body.

By the term "absorbent material" is meant a material that exhibits some absorbency or some liquid retention properties, such as

EP 2 813 201 SAP material, cellulose fibers as well as synthetic fibers. Typically, the adhesives used in the production of absorbent pads do not exhibit any absorbent properties and are not considered absorbent material. The SAP content may be higher than 80%, for example at least 85%, at least 90%, at least 95%, and even up to and including 100% of the weight of the absorbent material contained in the liner. This provides a relatively thin insert compared to a traditional insert typically containing 40-60% SAP material and high cellulose fiber content. The absorbent material may in particular contain less than 10% by weight of natural or synthetic fibers or less than 5% by weight, even being substantially free of natural and / or synthetic fibers. The absorbent material may advantageously contain little or no fibers of aerated fibre (cellulosic) material, in particular the absorbent core may contain less than 15%, 10%, 5% of fibers of aerated fibre (cellulosic) material by weight of the absorbent core, and may even be substantially free of cellulose fibers.

Cartridges containing relatively high SAP content with various cartridge designs have been proposed in the past, for example in the following publications: US 5.599.335 (Goldman), EP 1.447.066 (Busam), WO95 / 11652 (Tanzer), US2008 / 0312622A1 (Hundorf) , WO2012 / 052172 (Van Malderen) and WO2012 / 170778 (Rosati et al., See also WO2012 / 170779, WO2012 / 170781 and WO2012 / 1708008). The absorbent body may be thin, for example having a thickness not exceeding 5 mm, p. from 1 to 4 mm, as measured in the dry absorbent core thickness test disclosed herein.

The absorbent body 28 of the absorbent article of Fig. 1 shown separately in Fig. 4-6. The absorbent body and its description are provided by way of example only and do not limit the scope of the claims. The absorbent body typically comprises a front edge 280, a back edge 282 and two longitudinal edges 284, 286 connecting the front edge 280 to the rear edge 282. The absorbent body also has a substantially flat top side and a substantially flat bottom side formed by the cover of the body. The front edge 280 of the pad is the edge of the pad placed toward the front edge of the absorbent article. The cartridge may include a longitudinal axis 80 'corresponding substantially to the longitudinal axis of the product 80, viewed from above in a flat view as in Fig. 1. Typically, the absorbent material may be advantageously distributed

EP 2 813 201 in greater amount towards the front edge than towards the rear edge because more absorption is required from the front. Typically, the front and back edges of the cartridge are shorter than the longitudinal edges of the cartridge. The cover of the insert can be formed by two nonwoven materials 16, 16 'which can be at least partially welded along the edges of the absorbent body. The first non-woven fabric can substantially form the entire top side of the cartridge shell, and the second non-woven fabric can substantially form the entire bottom side (16 ') of the cartridge shell. The top side and first nonwoven fabric are represented by the same number 16 in the drawings, the underside of the second nonwoven fabric by number 16 '. The insert cover can be at least partially welded along the front edge, back edge and / or two side edges to improve the retention of the absorbent material during use.

The absorbent body of the present invention may further comprise at least one adhesive, in particular to assist in immobilizing the SAP in the absorbent body and / or to attach the underside of the body of the sheath to the face of the body of the sheath through one or more substantially free area (s) ) on absorbent material. The first type of adhesive that can be used is the so-called additional adhesive (not shown), which can be applied to the inner surface of the top side and / or bottom side of the cartridge cover. The additional adhesive can be any traditional adhesive used in this application, in particular hot melt adhesive. Exemplary adhesives are based on adhesive polymers such as SIS (styrene-isoprene block copolymer), SBS (styrene-butadiene block copolymer) or mPO (metallocene polyolefin). The adhesive may also contain a binder such as hydrogenated hydrocarbon resin as well as oil and antioxidant. Hydrogenated hydrocarbon resins are made from mixed aromatic / aliphatic resins, which are then selectively hydrogenated to obtain a wide range of materials with low color, high stability and wide compatibility. Examples of commercially available adhesives are known as HL1358LO and NW1286 (both from HB Fuller) as well as

DM 526 (from Henkel).

Additional adhesives can be applied to the upper side and / or the bottom side of the cartridge cover in an average amount from 2 gsm to 20 gsm, in particular from 4 gsm to 10 gsm. Additional glue can be applied evenly or discontinuously, in particular as a series of stripes arranged regularly and

Longitudinally oriented, for example a series of auxiliary adhesive strips about 1 mm wide spaced from 1 mm to 3 mm apart. The area for applying additional glue to the inner surface of the top and / or bottom of the cartridge cover corresponds to the entire deposition area

8 absorbent material. The additional adhesive may assist in forming the connection of the cartridge housing 27 if sufficient pressure is applied in the material free area 26 to fix both edges of the cartridge housing. An additional adhesive layer can be applied to the inner surface of the underside, the inner surface of the top side or both inner surfaces of the cartridge cover.

Super absorbent polymer (SAP)

The term "superabsorbent polymer" ("SAP") as used herein refers to absorbent material, which is a crosslinked polymeric material that is capable of absorbing 0.9% aqueous saline in an amount equivalent to at least 10 times its weight as measured by the centrifugal retention capacity (CRC) test (EDANA method WSP 241.2-05E). The value of CRC in the case of SAP used may in particular exceed 20 g / g or be over 24 g / g or be in the range from 20 to 50 g / g or from 20 to 40 g / g or from 24 to 30 g / g. SAPs useful in the present invention include various water-insoluble but water-swellable polymers capable of absorbing large amounts of liquid.

The super absorbent polymer may be in a finely divided form, so that it may exhibit the ability to flow in a dry state. Typical molecular absorbent polymeric materials are made of poly (methacrylic acid) polymers. However, it can also be used e.g. starch-based molecular absorbent polymer material, as well as polyacrylamide copolymer, ethylene maleic anhydride copolymer, cross-linked carboxymethylcellulose, poly (vinyl alcohol) copolymers, cross-linked poly (ethylene oxide) and starch grafted polyacrylonitrile copolymer. The super absorbent polymer may be polyacrylates and polyacrylic acid polymers that are internally and / or surface crosslinked. Preferred materials are described in PCT patent application WO07 / 047598 or for example in WO07 / 046052 or for example in WO2009 / 155265 and WO2009 / 155264. In some embodiments, preferred super absorbent polymer particles can be obtained by methods

EP 2 813 201 of production according to the prior art, which are described in more detail in WO2006 / 083584. The superabsorbent polymers are preferably internally crosslinked, i.e. polymerization is carried out in the presence of compounds containing at least two polymerization groups that can be copolymerized free radical into the polymer network. Useful cross-linking agents include, for example, ethylene glycol dimethacrylate, ethylene glycol diacrylate, allyl methacrylate, trimethylolpropane triacrylate, triallylamine, tetraallyloxyethane described in EP 530.438, di- and triacrylates described in EP 547.847, EP 559.476, EP63232 , WO03 / 104299,

WO03 / 104300, WO03 / 104301 and DE 103 31 450, mixed acrylates which, in addition to acrylate groups, contain additional ethylenically unsaturated groups described in publications DE 103 31 456 and DE 103 55 401, or mixtures of crosslinkers described for example in publications DE 195 43 368 , DE 196 46 484, WO90 / 15830 and WO02 / 32962, as well as the crosslinking agents described in WO2009 / 155265.

The super absorbent polymer particles may be crosslinked on the outer surface or postlinked. Useful post-crosslinking agents include compounds having at least two groups capable of forming covalent bonds with the carboxyl groups of polymers. Useful compounds include, for example, alkoxysilyl compounds, diamine, polyamines, polyamidoamines, di- or polyglycidyl compounds described in publications EP083.022, EP543.303 and EP937.736, polyhydric alcohols described in DE-C 33 14 019, cyclic carbonates described in DEA 40 20 780, 2-oxazolidone and its derivatives, such as N- (2-hydroxyethyl) -2-oxazolidone described in DE-A 198 07 502, bis- and poly-2-oxazolidones described in DE-A 198 07 992, 2-oxotetrahydro-1,3-oxazine and its derivatives described in DE-A 198 54 573, N-acyl-2-oxazolidones are described in DE-A 198 54 574, cyclic ureas described in publication DE-A 102 04 937, bicyclic amidoacetals described in DE-A 103 34 584, oxetanes and cyclic ureas described in EP1.199.327 and morpholine-2,3-dione and its derivatives described in WO03 / 031482.

SAPs may be formed from polyacrylic acid polymers / polyacrylate polymers, e.g. having a degree of neutralization of 60% to 90%, or about 75%, e.g. containing sodium counterions. Preferred SAP can also be obtained, for example, in inverse suspension polymerization as described

EP 2 813 201 in patents US 4,340,706 and US 5,849,816 or in dispersion polymerization in aerosol or other gas phases as described in patents US 2009/0192035, US 2009/0258994 and US 2010/0068520. In some embodiments, preferred SAP can be obtained by manufacturing methods of the prior art, which are described in more detail from page 12, line 23 to page 20, line 27 in WO2006 / 083584.

The absorbent body usually contains only one type of SAP, but the possibility of using a SAP blend is not excluded. The fluid permeability of a super absorbent polymer can be quantified using the Urine Permeability Measurement (UPM) value as measured in the test of European Patent Application EP 12174117.7. For example, the UPM value for SAP can be at least 10 x10^-7cm³.s / g or at least 30 x10^-7 cm³.s / g or at least 50 x10^-7 cm³.s / g or more, e.g. at least 80 or 100 x10^-7 cm³.s / g. The flow characteristics can also be adjusted by changing the amount and distribution of SAP used in the absorbent body.

For most absorbent products, liquid secretions usually occur in the front half of the article, especially in the diaper. The front half of the product (defined by the area between the front edge and the transverse line located halfway L from the front or rear edge) can therefore contain the majority of the absorbent capacity of the insert. Thus, at least 60% of the SAP material or at least 65%, 70%, 75% or 80% of the SAP material may be present in the front half of the absorbent product, with the remaining SAP material being positioned in the rear half of the absorbent product.

The total amount of SAP material present in the absorbent body may also vary depending on the intended use. For baby diapers, less SAP may be required than for baby diapers or incontinence adults. The amount of SAP in the cartridge may, for example, be in the range of 5 to 60 g, in particular 5 to 50 g. The average SAP basis weight in (or "at least one" if several are present) SAP polymer deposition area 8 may for example be at least 50, 100, 200, 300, 400, 500 or more g / m². In order to calculate this average basis weight, material free areas are determined 26

EP 2 813 201 present in the deposition area 8 of absorbent material based on the deposition area of ​​absorbent material.

Absorbent material 60

The absorbent material may be a continuous layer in the sheath of the pad, which can be obtained, for example, by applying a single, continuous layer of absorbent material. The absorbent material may also consist of individual pockets or strips of absorbent material surrounded by a sheath of the insert. A continuous layer of absorbent material, in particular SAP, can also be obtained by joining two absorbent layers with a discontinuous pattern of applying the absorbent material, whereby the resulting layer is substantially distributed in the deposition area of ​​the absorbent particulate polymeric material, as disclosed, for example, in US Patent Application 2008 / 0312622A1 (Hundorf). As exemplified in Fig. 4-6, the absorbent core 28 may thus comprise a first absorbent layer and a second absorbent layer, the first absorbent layer comprising a first substrate 16 and a first layer 61 of absorbent material, which may be 100% SAP and a second absorbent layer comprising a second substrate 16 'and a second layer 62 of absorbent material, which can also be 100% SAP. The first and second SAP layers can be applied as transverse stripes or "field areas" of the same width as the required area for the absorbent material to be deposited on a suitable substrate before joining. The strips may advantageously contain a different amount of absorbent material (SAP) to provide a profiled basis weight along the longitudinal axis of the insert 80 '. The first substrate 16 and the second substrate 16 'may form a cartridge housing.

Fibrous thermoplastic adhesive 51

The absorbent body may also contain fibrous thermoplastic adhesive material 51, in particular microfiber adhesive, to further immobilize the absorbent material inside the body of the body. The fibrous thermoplastic adhesive material 51 can at least partially bond each layer of absorbent material 61, 62 with its respective substrate. The fibrous thermoplastic adhesive material 51 may be at least partially in contact with the absorbent material 61, 62 in the field areas and at least partly in contact with the substrate layer in the connection areas. This gives a substantially three-dimensional structure to the fibrous layer of thermoplastic adhesive material 51, which in itself is a substantially two-dimensional structure with a relatively

EP 2 813 201 of small thickness compared to the dimension in length and width. In this way, the fibrous thermoplastic adhesive material can provide recesses to cover the absorbent material in the field area, and thereby immobilizes this absorbent material, which can be 100% SAP.

The thermoplastic polymer typically has a molecular weight (Mw) above

000 and glass transition temperature (Tg) usually below room temperature or in the range -6 ° C> Tg <16 ° C. Typical polymer concentrations in the hot melt adhesive range from about 20 to about 40% by weight. Thermoplastic polymers may be insensitive to water. Examples of polymers are (styrene) block copolymers containing ABA tri-block structures, AB double-block structures and radial (AB) n block copolymer structures, in which A blocks are non-elastomeric polymer blocks, usually including polystyrene, and B blocks are unsaturated conjugated or (partly) dienes hydrogenated varieties of these. Block B is usually isoprene, butadiene, ethylene / butylene (hydrogenated butadiene), ethylene / propylene (hydrogenated isoprene) and mixtures thereof. Other preferred thermoplastic polymers that can be used are metallocene polyolefins, which are ethylene polymers made using single-active catalysts or metallocene catalysts. In this case, at least one comonomer can be polymerized with ethylene to form a copolymer, terpolymer or a higher order polymer. Amorphous polyolefins or amorphous polyalphaolefins (APAO), which are homopolymers, copolymers or terpolymers of alpha C2 to C8 olefins are also suitable for use.

For example, the adhesive resin may have a molecular weight below 5000 and Tg typically above room temperature, typical hot melt resin concentrations range from about 30 to about 60%, while the plasticizer has a low molecular weight typically below 1000 and Tg below room temperature, with typical concentrations from about 0 to about 15%.

The thermoplastic adhesive material used to form the fibrous layer may advantageously have elastomeric properties for the invention so that the layer formed by the fibers on the SAP layer is able to stretch as the SAP material swells. An example of an elastomeric hot melt adhesive contains thermoplastic elastomers such as ethylene vinyl acetate copolymers, polyurethanes, polyolefin blends of hard ingredients (most often crystalline polyolefin, e.g. polypropylene or polyethylene) with soft ingredients

EP 2 813 201 (such as ethylene propylene rubber); copolyesters such as a copolymer of polyethylene terephthalate with ethylene azelate; and thermoplastic elastomer block copolymers with thermoplastic end blocks and rubber center blocks designated as ABA block copolymers;

blends of structurally different homopolymers or copolymers, e.g., a blend of polyethylene or polystyrene with an ABA block copolymer; blends of a thermoplastic elastomer with a low molecular weight resin modifier, e.g., a blend of styrene-isoprene-styrene block copolymer with polystyrene; and the elastomeric hot melt pressure sensitive adhesives described herein. Elastomeric hot melt adhesives of this type are described in detail in US Patent 4,731,066 (Korpman).

The fibers of the thermoplastic adhesive material 51 may, for example, have an average thickness from about 1 to about 50 microns or from about 1 to about 35 microns and an average length from about 5 mm to about 50 mm or from about

5 mm to about 30 mm. In order to increase the adhesion of the thermoplastic adhesive material to the substrate or to any other layer, in particular to any other nonwoven layer, such layers may be pre-treated with an additional adhesive. The fibers adhere to each other to form a fibrous layer, which can also be referred to as a mesh.

In the case of an absorbent body, a loss of SAP of no more than about 70%, 60%, 50%, 40%, 30%, 20% or 10% according to the wet immobilization test in US 2010 / 0051166A1 can advantageously be achieved.

Absorption area 8

The deposition area 8 of the absorbent material may be defined by the periphery of the layer formed by the absorbent material 60 within the cover of the insert as seen from the top side of the absorbent insert. The deposition area of ​​the absorbent material 8 may have a substantially rectangular shape, for example as shown in Fig. 4, but it is also possible to use other shapes, such as "T", "Y", "hourglass" or "dog bone". The deposition area in particular, which may have a narrowing width in the direction of the medial or perineal region of the insert. As a result, the deposition area of ​​the absorbent material can have a relatively narrow width in the area of ​​the refill intended to be placed in the perineum region of the absorbent hygiene article. This may, for example, allow for a larger one

EP 2 813 201 comfort during use. The width (measured in the transverse direction) of the deposition area of ​​the absorbent material 8 can thus be equal to its narrowest area, which has a width of less than 100 mm, 90 mm, 80 mm, 70 mm, 60 mm or even less than about 50 mm. The narrowest width may furthermore be at least 5 mm, or at least 10 mm, be less than the width of the embedding area at its largest point in the front and / or rear regions of the embedding area 8.

The basis weight (amount deposited per unit area) of SAP material may also vary in the deposition area 8 to provide a contoured distribution of the absorbent material, in particular SAP material, in the longitudinal direction, transverse direction or in both directions of the insert. Accordingly, the basis weight of the absorbent material may vary along the longitudinal axis of the insert as well as along a transverse axis or any axis parallel to any of these axes. The basic SAP weight in an area with a relatively high basic weight can be, for example, at least 10%, 20%, 30%, 40% or 50% higher than in an area with a relatively low basic weight. In particular, the amount of SAP present in the deposition area of ​​the absorbent material in the longitudinal position at the crotch point C may be greater per unit of the deposited surface compared to another area of ​​deposition of the absorbent material 8.

The absorbent material can be deposited using known methods that can allow relatively precise deposition of SAP material at a relatively high speed. In particular, the SAP printing technology disclosed in, for example, patents may be used

US2006 / 24433 (Blessing), US2008 / 0312617 and US2010 / 0051166A1 (both for Hundorf et al.). This method uses a print roller to deposit SAP material on a substrate disposed on a support element mesh that may include a plurality of crossbars extending substantially parallel to each other and separated from each other to form channels extending between the multiple crossbars. This technology enables precise SAP deposition at high speed onto the substrate in particular to obtain one or more areas 26 substantially free of absorbent material surrounded by the absorbent material. Substantially free areas of absorbent material can for example be created by changing the grid and drum pattern

EP 2 813 201 receivers, whereby SAP is not applied in selected areas, as for example disclosed in US2012 / 0312491 (Jackels).

Cartridge cover 16, 16 '

The insert cover may be made of a single substrate wrapped around absorbent material or may preferably contain two (or more) substrates that are attached to each other. Typical fasteners are the so-called C cover and / or multi-layer cover. In the cover C, shown for example in Fig. 5, the longitudinal and / or transverse edges of one of the substrates are wrapped on the other substrate, forming flaps. These flaps are then attached to the outer surface of another substrate, typically by gluing.

The cartridge cover is formed by typical substrate materials used in the production of conventional cartridges, in particular paper, tissue paper, films, fabrics or nonwovens or laminates of any of these materials. In particular, the sheath of the insert may be formed by a nonwoven, for example carded nonwoven, mass formed nonwoven ("S") or melt blown nonwoven ("M") and laminates of any of these materials. For example, suitable materials are melt-spun polypropylene nonwovens, in particular nonwovens with a laminated SMS, SMMS or SSMMS structure and having a basis weight in the range from about 5 gsm to 15 gsm. Preferred materials are disclosed, e.g. in patents US 7,744,576, US 2011 / 0268932A1, US 2011 / 0319848A1 and US 2011 / 0250413A1. Nonwovens made of synthetic fibers such as PE, PET and in particular PP may be used.

If the insert cover includes a first substrate 16 and a second substrate 16 ', they may be made of the same type of material, they may be made of different materials, or one of the substrates may be treated differently than the other to provide different properties. Since the polymers used to make the nonwoven fabric are inherently hydrophobic, they can advantageously be coated with hydrophilic coatings when placed on the fluid receiving side. It is preferred that the top side of the cartridge cover, i.e. the side in the absorbent article placed closer to the user was more hydrophilic than the underside of the insert shell. A possible method of producing nonwovens with resistant hydrophilic coatings is to apply a hydrophilic monomer and free radical polymerization initiator to the nonwoven and to carry out UV-activated polymerization, resulting in

EP 2 813 201 results in a monomer chemically bonded to the surface of the nonwoven fabric. An alternative possible method of producing nonwovens with resistant hydrophilic coatings is coating the nonwoven with hydrophilic nanoparticles, e.g.

described in WO 02/064877.

In some embodiments, durable hydrophilic nonwovens are also useful. Surface tension can be used to measure how permanently a certain level of hydrophilicity is achieved. Liquid permeation can be used to measure the level of hydrophilicity. The first and / or second substrate may in particular exhibit a surface tension of at least

55, more preferably at least 60 or most preferably at least 65 mN / m or higher after wetting with the saline solution. The substrate may also have a liquid permeation time of less than 5 seconds for the fifth fluid stream. These values ​​can be measured using the test methods described in US 7,744.576B2 (Busam et al.): "Determination Of Surface Tension" and "Determination of Strike Through", respectively.

Hydrophilicity and wetting are typically determined by the angle of contact and the time the fluids penetrate, for example, through a nonwoven fabric. This is discussed in detail in the American Chemical Society's publication, Contact angle, wettability and adhesion, published by Robert F. Gould (copyright 1964). It can be concluded that a substrate with a smaller contact angle between water and the surface of the substrate is more hydrophilic than others.

Substrates may also be air-permeable. The coatings used herein may therefore contain micropores. The substrate may have, for example, air permeability of 40 or 50 to 300 or up to 200 m³/ (M²x min), according to the value determined according to the EDANA method 140-199 (125 Pa, 38.3 cm²). Optionally, the cartridge sheath material may exhibit lower air permeability, e.g., not air permeable, to facilitate absorption on a moving surface under the action of a vacuum.

If the insert cover is formed by two substrates 16, 16 ', four seals can typically be used to surround the absorbent material 60 with the insert cover. For example, the first substrate 16 may be placed on one side of the cartridge (top side as shown in the figures) and extend around the longitudinal edges of the cartridge to at least partially wrap the opposite

EP 2 813 201 the bottom side of the cartridge. The second substrate 16 'may typically be located between the wrapped flaps of the first substrate 16 and the absorbent material 60. The flaps of the first substrate 16 may be glued to the second substrate 16 'to provide a strong seal. The so-called C-shell design can provide benefits such as greater wet cracking resistance compared to a multi-layer seal. The front edge and the back edge of the insert shell can then also be sealed, for example, by gluing the first substrate and the second substrate together to ensure complete absorption of the absorbent material across the entire periphery of the insert. In the case of the front and rear edges of the insert, the first and second substrates can protrude and can be connected to each other in a direction substantially on one plane, forming in the case of these edges a so-called multilayer structure. In the so-called multilayer construction, the first and second substrates can also protrude outwards from all sides of the insert and can be sealed flat along all or part of the insert's rim, typically by gluing and / or hot / under pressure. Typically, neither the first nor the second substrate need to be formed so that they can be cut in the shape of a rectangle to facilitate production, but of course other shapes are possible.

The term "weld" should be understood in a broad sense. The seal does not have to run continuously along the entire periphery of the cartridge casing, but it can run discontinuously along part or all of it, such as formed by a series of seal points arranged in a line. Typically, the weld can be formed by gluing and / or thermal welding. The cartridge cover may also be formed by a single substrate that may surround the absorbent material as a package and be sealed along the front and rear edges of the cartridge and one longitudinal seal.

Area or areas 26 substantially free of absorbent material and channels 26 '

The absorbent body comprises at least a pair of areas 26 that are substantially free of absorbent material. The term "substantially free" means that in each of these areas the basis weight of the absorbent material is at least less than 25%, in particular less than 20% or 10%, of the average basis weight of the absorbent material in the remainder of the insert. In particular, absorbent material may not be present in these areas at all. Minimal quantities such as

Accidental contaminants with absorbent material that may occur during the manufacturing process are not treated as absorbent material. The areas 26 are preferably surrounded by absorbent material when viewed in the plane of the pad, which means that the areas 26 do not extend to any of the edges of the absorbent material deposition area.

The top side 16 of the cartridge housing is attached to the bottom side 16 'of the cartridge housing by means of the connections of the cartridge housing 27 through these areas 26 substantially free of absorbent material. As shown in Fig. 3, as the absorbent material swells, the cartridge sheath connection remains at least initially attached in areas substantially free of material 26. The absorbent material swells in the remainder of the pad after the liquid has been absorbed, whereby the pad shell forms one or more channels 26 'along areas 26 substantially free of absorbent material including the pad shell 27 connection. These 26 'channels are three-dimensional and can be used to distribute liquid secretions along their length to a wider area of ​​the cartridge. This can ensure faster liquid accumulation and better utilization of the absorbent capacity of the insert. As will be explained further below, the channels 26 'may also provide deformation to the fibrous layer 54 and provide grooves 29 in the fibrous layer 54. It is not excluded that the absorbent core may include other areas substantially free of absorbent material, but without the core of the pad being attached, but when wet these unconnected areas will not normally form a channel.

The top and bottom sides of the cartridge cover can be attached together continuously along areas 26 substantially free of absorbent material, but the connection of the cartridge cover 27 can also be discontinuous (intermittent), for example by means of a series of point connections. Typically, the adhesive can be used to attach the top side to the bottom of the cartridge sheath, but it is possible to connect by other known methods such as pressure bonding, ultrasonic bonding, hot bonding, or combinations thereof. The attachment of the top and bottom sides of the cartridge cover may be provided by one or more adhesive materials, in particular one or more layers of additional adhesive and / or one or more layers of fibrous adhesive material, if present in the cartridge as indicated above. These adhesives can therefore serve the dual function of immobilizing the absorbent material and fixing the top and bottom sides of the pad together.

EP 2 813 201

The following examples of the shape and size of areas 26 substantially free of absorbent material are not limiting. In general, the connection of the cartridge housing 27 may have the same outline, but slightly smaller size than the areas 26 due to the tolerance required in the production process. Areas substantially free of material 26 may be present in the perineal region of the article, in particular at least at the same longitudinal level as the crotch point C, as shown in Fig. 4 by means of two longitudinally extending regions substantially free of absorbent material 26. The absorbent body 28 may also comprise more than two areas substantially free of absorbent material, for example at least 3, or at least 4 or at least 5 or at least 6. The absorbent body may comprise one or more pairs of areas substantially free of absorbent material arranged symmetrically with respect to the longitudinal axis 80 '. Shorter areas free of absorbent material may also be present, for example in the posterior or anterior region of the inlay, as exemplified in the drawings in WO2012 / 170778.

Areas that are substantially free of absorbent material can extend substantially longitudinally, which typically means that each area extends more in the longitudinal direction than in the transverse direction and typically at least twice as much in the longitudinal direction as in the transverse direction (as measured according to axis). The areas 26 substantially free of absorbent material can be L 'projected onto the longitudinal axis 80 of the pad, which is at least 10% of the length L of the absorbent article. It may be advantageous if at least some or all of the areas 26 are not completely or substantially completely transversely oriented channels in the cartridge.

Areas substantially free of absorbent material can be completely oriented longitudinally and parallel to the longitudinal axis, but can also be curved. In particular, some or all of these areas, in particular areas present in the perineum region, may have a concave shape in the direction of the longitudinal axis 80 ', as exemplified in Fig. 4 for a pair of 26 'channels. The radius of curvature can usually be at least equal (and preferably at least 1.5 or at least 2.0 times greater than this average transverse dimension) to the average transverse dimension of the deposition area of ​​the absorbent layer 8; and which are also straight but inclined at an angle (e.g. from 5 °) to

EP 2 813 201

30 ° or, for example, up to 20 ° and even 10 ° in relation to a line parallel to the longitudinal axis. The radius of curvature may be constant in an area substantially free of absorbent material, or may vary in its length. This may also include areas free of absorbent material and inclined at an angle, provided that said angle between the two channel parts is at least 120 °, preferably at least 150 °; and in each of these cases, provided that the longitudinal dimension of the area is greater than the transverse dimension. These areas may also be branched, for example a central area substantially free of absorbent material may overlap the longitudinal axis in the perineum region which branches off towards the back and / or front of the article.

In some embodiments, there are no areas substantially free of absorbent material overlapping the longitudinal axis 80 of the cartridge. If they are present as one pair symmetrical about the longitudinal axis, the areas substantially free of absorbent material may be spaced apart along the entire longitudinal dimension. For example, the smallest distance may be at least 5 mm, at least 10 mm or at least 16 mm.

In addition, in order to reduce the risk of liquid leakage, areas substantially free of absorbent material may preferably not extend to any of the edges of the absorbent material deposition area 8 and are thus surrounded and fully contained in the absorbent material deposition area 8. Typically, the smallest distance between the area substantially free of absorbent material and the nearest edge of the deposition area of ​​the absorbent material is at least 5 mm.

Areas substantially free of absorbent material may have a width Wc along at least a portion of their length which is at least 2 mm or at least 3 mm or at least 4 mm, a maximum of for example 20 mm, or 16 mm or 12 mm. The width Wc of areas substantially free of absorbent material may be constant over the entire length or may vary in length.

The formation of the channels 26 'in the absorbent body may begin when the absorbent material absorbs liquid and swells. As the pad absorbs more liquid, the cavities inside the absorbent pad formed by the channels become deeper and more visible both visually and in touch. It is possible to create a sufficiently strong connection of the cover

EP 2 813 201 in combination with a relatively small amount of SAP so that the channels remain stable until the absorbent material is completely saturated. On the other hand, the connections of the insert shell may in some cases limit the swelling of the absorbent material when the insert is substantially loaded. In this way, the inventors have found that the connection of the cartridge housing 27 can also be implemented so that it opens in a controlled manner in the case of large amounts of liquid. The joints must be essentially intact at least during the first phase, when the absorbent material absorbs a moderate amount of liquid. In a second phase, the connection of the insert cover 27 in the channels may begin to open to provide more space for the swellable absorbent material while maintaining beneficial channel properties such as greater insert elasticity in the transverse direction and liquid retention. In the third phase, corresponding to a very high level of saturation of the absorbent body, more channel connections can be opened to provide even more space for the swelling absorbent material. The strength of the connection of the cartridge housing 27 in the channels can be controlled, for example, by varying the amount and type of glue used to attach the two sides of the cartridge housing, the pressure value used to form the cartridge housing connection and / or the distribution of absorbent material, as more absorbent material usually results in greater swelling. and puts more pressure on the connection. The expansion of the cartridge shell material can also play a significant role.

The resistance to delamination of the junction of the insert casing in the channels can be quantified using the immersion delamination test described below, which briefly consists of rapidly immersing the absorbent body in an excess of 0.9% by weight salt solution at 37 ° C and recording the quantity channels that have stratified. While this does not limit the scope of the first aspect of the invention, the behavior of the cartridge sheath connections may be as follows:

- less than one third of the initial length of the cartridge guard connection is delaminated after 10 minutes;

- one-third to two-thirds of the initial length of the cartridge sheath connection delaminates after 20 minutes;

- at least two-thirds of the initial length of the cartridge cover connection delaminates after 60 minutes.

EP 2 813 201

Fibrous layer 54 and grooves 29

The absorbent layer comprises a fibrous layer 54. The fibrous layer is between the cover layer 24 and the absorbent body 28 as shown in the figures. The absorbent article may also comprise a fibrous layer according to the invention between the bottom layer and the absorbent core and the top layer and the absorbent core. The fibrous layer 54 is at least partially bonded to the top or bottom side of the liner shell in areas substantially free of absorbent material. As will be discussed in more detail below, the formation of channels in the absorbent body as the absorbent material swells, thereby creates one or more corresponding grooves in the fibrous layer.

The fibrous layer can be of any type, such as non-woven fabric, or even loose fibers. The fiber layer may in particular be of the type known in the art for the collection layers and / or distribution layers. The fibrous layer is at least partially bonded to the top side 16 of the insert shell in areas 26 substantially free of absorbent material. The inventors have found that this connection allows the fibrous layer to follow the cavity formed by the channels 26 as the absorbent body absorbs liquid and swells. In this way, the formation of one or more channels 26 results in the formation of one or more respective grooves 29 in the fiber layer. The grooves 29 formed in the fibrous layer provide improved liquid handling properties, in particular these grooves are used to distribute fluid secretions along the length of the groove. The grooves 29 can usually have the same contour as the corresponding channels 26 '. The depth of the grooves typically depends on the type of fiber, thickness, basis weight of the fiber layer, and of course the amount of fluid absorbed by the absorbent body. A better and more flexible fiber layer can, for example, provide deeper grooves. The depth of the grooves can be substantially proportional to the depth of the channels so that it changes as the absorbent body swells.

Typically, the fibrous layer 54 does not contain SAP, as it may slow down the accumulation and spreading of liquid. The prior art discloses many types of fibrous layers that can be used as a collecting layer and / or a spreading layer, see for example WO2000 / 59430 (Daley), WO95 / 10996 (Richards), US 5,700.254 (McDowall), WO02 / 067809 (Graef).

EP 2 813 201

The fibrous layer can serve as a spreading layer that can disperse liquid secretions over a larger internal surface of the product, so the absorbent capacity of the insert can be used more efficiently. Typically, the distribution layers are made of nonwoven based on synthetic or cellulose fibers and have a relatively low density. The density of the distribution layer may vary depending on the product's packing, but typically it is in the range of 30 to 250 kg / cm³ (from 0.03 to 0.25 g / cm³), in particular from 50 to 150 kg / m³ (from 0.05 to 0.15 g / cm³) when measuring at a pressure of 2.07 kPa (0.30 psi). The spreading layer may also be a material having a water retention index of 25 to 60, preferably 30 to 45, measured by the method disclosed in US Patent 5,177,537. Typically, the average basis weight of the spreading layer may be from 30 to 400 g / m2², in particular from 100 to 300 g / m2².

For example, the spreading layer may contain at least 50% by weight of crosslinked cellulosic fibers. Cross-linked cellulose fibers may be folded, twisted or spirally wound, or may be a combination thereof, including folded, twisted and spiral wound. This type of material has been used in the past in disposable diapers as part of a collection system, for example disclosed in the patent

US 2008/0312622 A1 (Hundorf). Cross-linked cellulose fibers provide greater flexibility and, as a consequence, greater resistance of the first absorbent layer to compression in the product packaging or in conditions of use, e.g. under the influence of the child's weight. This allows for a cartridge with greater empty space, liquid permeability and absorption, and thus less leakage and greater dryness.

Examples of chemically crosslinked cellulosic fibers preferred for use in the spreading layer are disclosed in US 5,549.791, US 5,117,537, WO9534329 or US2007 / 118087. Examples of crosslinkers include polycarboxylic acids, such as citric acid and / or polyacrylic acids, such as copolymers of acrylic acid and maleic acid. For example, cross-linked cellulose fibers may contain between about 0.5 mole% and about 10.0 mole% cross-linking C2 -C9 multicarboxylic acid, calculated on the basis of the molar content of cellulose glucose units bound to said fibers by means of intra-fiber cross-linking bonds

EP 2 813 201 ester. The cross-linking C2-C9 polycarboxylic acid can be selected from the group consisting of:

- C2-C9 aliphatic and alicyclic polycarboxylic acids characterized by at least three carboxyl groups per molecule; and

- aliphatic and alicyclic C2 -C9 polycarboxylic acids characterized by two carboxyl groups per molecule and a double carbon bond located in the alpha, beta unit of one or both carboxyl groups, where one of the carboxyl groups of said cross-linking C2-C9 polycarboxylic acid is separated from the other group with two or three carbon atoms. In particular, the fibers may contain between about 1.5 mole% and about 6.0 mole% cross-linking agent calculated on the basis of cellulose glucose units and be bonded to each other by intra-fiber ester cross-linking. The cross-linking agent can be selected from the group consisting of citric acid, 1, 2, 3, 4 butanetetracarboxylic acid and 1, 2, 3 propanetricarboxylic acid, in particular citric acid.

Cross-linked polyacrylic acid can also be selected from polyacrylic acid homopolymers, acrylic acid copolymers and mixtures thereof. The fibers may contain these crosslinkers in an amount ranging between 1.0% and 10.0% by weight, preferably between 3% and 7% by weight calculated on the basis of dry fiber weight, and be bonded together by means of intra-fiber ester bonds crosslinking. The crosslinking agent may be a polyacrylic acid polymer with a molecular weight in the range from 500 to 40,000 and preferably from 1,000 to 20,000. The crosslinking polymer polyacrylic acid may be a copolymer of acrylic acid and maleic acid, in particular in which the weight ratio of acrylic acid to maleic acid is in the range from 10: 1 to 1: 1, preferably from 5: 1 to 1.5: 1. The effective amount of citric acid can then be mixed with said crosslinking polymer acrylic acid.

The distribution layer containing the cross-linked cellulose fibers may contain other fibers, but this layer may preferably contain at least 50%, or 60%, or 70%, or 80%, or 90% or even 100% by weight of the layer consisting of cross-linked cellulose fibers ( including cross-linking agents). Examples of such a mixed layer of crosslinked fibers

The cellulosic fibers may contain about 70% by weight chemically crosslinked cellulose fibers, about 10% by weight polyester (PET) fibers and about 20% by weight unprocessed fiber. In another example, the crosslinked cellulose fiber layer may contain about 70% by weight chemically crosslinked cellulose fibers, about 20% by weight lyocell fibers and about 10% by weight PET fibers. In another example, this layer may contain about 68% by weight chemically crosslinked cellulosic fibers, about 16% by weight unprocessed pulp and about 16% by weight PET fibers. In another example, the crosslinked cellulose fiber layer may contain from about 90-100% by weight of chemically crosslinked cellulose fibers.

The fibrous layer can also serve as a collecting layer, the task of which can be to quickly accumulate liquid from the top layer to provide the user with a good level of dryness. Such a collecting layer is typically placed directly under the top layer. The absorbent article may also include a spreading layer 52 in addition to the fibrous layer 54, as shown for example in Figures 12-13. A spreading layer 52, if present, can be at least partially distributed over the fibrous layer 54.

The collecting layer can usually be formed or contain a nonwoven material, e.g. an SMS or SMMS material, consisting of a mass formed layer, a melt blown layer and an additional mass formed layer or alternatively a carded chemically bonded nonwoven material. In particular, the nonwoven material can be combined with latex. Exemplary upper collecting layers 52 are disclosed in US 7,786,341. Carded, resin-bonded nonwovens can be used, in particular when the fibers used are in the form of solid round or round fibers and hollow PET staple fibers (50/50 or 40/60 blend of 6 or 9 fibers in denier). An example of a binder is styrene butadiene / latex. The advantage of nonwovens is the possibility of their production outside the processing line and their storage and use as a roll of material.

Further useful nonwovens are described in US 6,645,569, US 6,863,693 (both for Cramer), US 7,122,621 (Rohrbaugh), and patent applications US2003 / 148684 for Cramer et al. and US2005 / 008839 (both for Cramer).

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Such a collecting layer 52 can be stabilized with a latex binder, e.g. a styrene-butadiene latex binder (SB latex). Methods for making such latexes are known, for example, from European Patent No. 149 880 (Kwok) and US Patent 2003/0105190 (Diehl et al.). In some embodiments, the binder may be present in the collection layer 52 in an amount greater than 12%, about 14% or about 16% by weight. SB latex is offered under the trade name GENFLO ™ 3160 (OMNOVA Solutions Inc .; Akron, Ohio, USA).

In addition to the first collecting layer described above, an additional collecting layer can be used. For example, a layer of tissue paper can be placed between the first acquisition layer and the distribution layer. Tissue paper may have better capillary distribution properties compared to the collecting layer discussed above. The size of the paper and the first acquisition layer may be the same or different, for example, the paper layer may protrude more backwards of the absorbent article than the first acquisition layer. An example of a hydrophyte paper is a wet strength paper of 22.5 gsm, made of cellulose fibers and manufactured by Havix.

The fibrous layer 54 is joined to the top side 16 of the cartridge sheath

The fibrous layer 54 can be bonded to the top side of the cartridge shell by any conventional joining means, in particular glue bonding, but other joining means such as calendering, pressure bonding, melt bonding and pressure can also be used. The adhesive can be applied to the outer surface of the top side of the cartridge sheath or to the underside of the fibrous layer or to both surfaces, depending on the ease of application to the surface before joining the two layers. The adhesive may be applied to an area at least equal to the entire underside of the fibrous layer. The adhesive can also be applied to a smaller area than the underside of the fibrous layer.

The adhesive may be applied, for example, by means of a gap coating in the product production direction ("machine direction" or "MD"), typically parallel to the longitudinal direction of the product, but may also be applied using various techniques such as adhesive spraying or adhesive printing. For cost reasons, it may be advantageous not to apply the adhesive as a continuous layer in the application area, but in a discontinuous manner, e.g. using continuous or intermittent strips or

The gaps are separated by a gap, so that the actual adhesive coverage area is a fraction of the application area, typically from about 10 to about 50%.

Figures 7-11 illustrate various possibilities for applying adhesive between the cartridge cover and the fibrous layer. In these figures, only the adhesive application area 66 is shown, but of course another glue such as adhesive 68 between the top layer and the fibrous layer may be present, as exemplified in Figs. 12 and 13.

As exemplified in Fig. 7, the adhesive application area 66 between the fiber layer and the cartridge sheath can cover substantially the entire area of ​​the fiber layer 54. Typically, due to the limitation of high-speed production, a margin of several mm (e.g. about 5 mm) along the longitudinal sides of the fibrous layer may remain without glue (as shown in Fig. 8). As indicated above, the adhesive coverage area may generally be less than 100% of the application area. For example, the adhesive can be applied in a gap coating process using a series of parallel continuous gaps separated by a gap. The adhesive joints may have the same width or different widths and may be spaced at regular intervals or not. For example, the adhesive joints may have a width in the range from 0.5 mm to 3 mm and a gap between the joints in the range from approximately 1 mm to 5 mm. In one example, the glue joints joining the cartridge cover to the fibrous layer have a dimension of 1 mm and gaps 2 mm.

The cover layer 24 may also be attached directly or indirectly to the fibrous layer 54 in the area (s) corresponding to the area (s) 26 substantially free of absorbent material, where the channel (s) 26 'are formed, for example by gluing or by any means other means such as melting and pressing joining, calendering or joining under pressure or any combination thereof. The top layer can thus more easily follow the shape of the channels 26 'and the grooves 29 because they are formed when the absorbent material swells and auxiliary grooves 29' are formed on the surface of the product. The cover layer 24 may be directly attached to the fibrous layer, or indirectly if an additional layer is present between the cover layer and the absorbent body, e.g. a spreading layer 52 as further discussed and illustrated in Fig. 14. The fastening region 68 of the top layer to the fibrous layer 54 or other underlying layer 52 may extend along the entire length of the fibrous layer. This can be achieved, for example, by applying adhesive along the entire length of the top layer, as shown in Fig. 12.

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In this way, the top layer can be attached to the fibrous layer and in addition to the rest of the base of the absorbent article, e.g. absorbent body and bottom layer. The attachment area 68 may be formed by an adhesive, for example applied by means of a gap coating. The slots may typically extend in the longitudinal direction (MD) to facilitate production, but it is not excluded that they may also be applied in the transverse direction. The width of the attachment area 68 may be at least sufficient to cover or apply in (viewed from above) areas 26 substantially free of absorbent material. The amount of coverage, width and dimensions of the gaps, as indicated above for the adhesives connecting the fibrous layer with the insert cover, can also be used for the adhesive joints joining the top layer with the layer underneath (e.g. with fibrous layer 54 or spreading layer 52, if present).

FIG. 8 shows an alternative connection area between the sheath of the refill and the fibrous layer, the fibrous layer being bonded to the sheath of the refill in two longitudinally extending regions 66, 66 'separated by an unconnected zone in the central area of ​​the fibrous layer. The areas of the cartridge shell free of material 26 are in the areas of adhesive application 66, 66 '. Similarly, as for example shown in Fig. 13, the top layer can be attached directly or indirectly to the fibrous layer in two attachment areas 68, 68 'including areas free of absorbent material 26 and separated by an unattached zone.

FIG. 9 shows an alternative in which the fibrous layer is bonded only to the top side of the cartridge shell in areas substantially free of absorbent material 26 of the cartridge. This can be achieved with glue using a gap coating, but other techniques are considered possible, for example adhesive printing, which can be more adapted if the shape of the area substantially free of absorbent material 26 is curved. US Patent 8,186,296 discloses one example of adhesive printing technology. As indicated above and generally, the adhesive coverage area may be part of the application area, e.g. from 10% to 50%, but as in Fig. 9, if the adhesive application area is relatively limited, more coverage can be used up to 100% of the application area.

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Fig. 10 shows an alternative connection area in which the smaller area 66 of the fibrous layer is bonded to the sheath of the insert. In particular, part of the area (s) substantially free of material 26 may not be associated with the fibrous layer. However, it may be advantageous for at least 50% of the area 26 to be in the area of ​​application of binders, in particular glue.

Fig. 11 shows an alternative pattern of the connection area 66 between the cartridge housing and the fiber layer. In this example, the adhesive (or any other binding agent) may be applied in several joint areas 66 separated in a longitudinal direction by a number of adhesive-free areas. A portion of the area substantially free of material 26 may be outside the adhesive application area 66, however it may be advantageous that at least 50% of the area 26 be in the application area 66.

Typically, and as shown in the Figures, the top side of the absorbent body has a larger area than the fibrous layer. It is not excluded, however, that the fibrous layer may have a larger area than the cartridge cover, in which case the connection area may be as large or smaller than the area of ​​the top side of the cartridge cover.

Additional layer 52

The absorbent article may comprise a further layer (s) between the fibrous layer 54 and the top layer 24, e.g., a collection layer 52 and / or between the fibrous layer and the liner. FIG. 14 is a simplified cross-sectional view of an absorbent article further comprising an additional layer 52 between the top layer 24 and the fibrous layer 54. In Fig. 14 adhesive layers are depicted as having two application areas, but other application patterns are possible. The adhesive application area may be formed by gap coating or other adhesive application means and may have a coverage area that is only a fraction of the application areas. The additional layer 52, which may be a spreading layer, can also be adhesively bonded to the top layer and the fibrous layer in the area corresponding to the area (s)

26 essentially free of absorbent material. The absorbent article comprises adhesive 66 between the absorbent core 28 and the fibrous layer 54. The adhesive 66 attaches the outer surface of the top side of the sheath of the pad to the underside of the fibrous layer in areas 26 substantially free of absorbent material. The adhesive 67 may attach a fibrous layer 54 to an additional layer 52 i

Similarly, adhesive 68 may attach an additional layer 52 to the top layer 24.

It may be advantageous to ensure that all layers between the top side of the cartridge cover and the top layer are at least partially bonded in an area (areas) of the cartridge that is substantially free of material

26. The advantages of this design are shown in Fig. 15, in which the product of Fig. 14 wet. The absorbent material absorbed the liquid and swelled to a moderate amount, so that the sheath of the insert 27 is still present. The channels 26 'formed by the sheath of the refill and the swollen absorbent material cause the formation of corresponding grooves 29 in the fibrous layer 54, as well as in other layers that have been indirectly bonded to the sheath of the refill, in this case an additional layer 52 (e.g. collecting layer) and top layer 24. The top layer can thus be bonded (by means of glue 68 or other binding agent) to the layer directly underneath, which can be a spreading layer 52 and the layer underneath with the fiber layer 54 by means of glue 67 or any other binding agent. The adhesives that can be used between different layers can be any conventional adhesives, e.g. hot melt adhesives applied by means of a gap coating, as spheres or by using other application options such as adhesive printing (e.g.

disclosed in US 8,186,296).

Depending on the amount of absorbent material contained in the absorbent body, the absorbent body may swell to a certain volume and then reach saturation in a state similar to that shown in Fig. 15, wherein the combination of cartridge housing 27 and channels 26 'remain present. The absorbent body may also contain more absorbent materials such that they swell to a larger volume, which may cause the connection of the body of the body 27 to be at least open in a part of the channel (s). This is shown in Fig. 16, wherein the connection of the cartridge housing 27 has been opened. When the connection of the cartridge cover 27 is opened, the channels 26 'and the grooves 29 may become less visible or disappear completely in the open area.

Fastening system 42, 44

The absorbent article may include a fastening system. The fastening system can be used to provide transverse stress on the perimeter of the absorbent article to keep the absorbent article on the user's body, which is

EP 2 813 201 typical for diapers fastened with a tape. The attachment system is not necessarily intended for training pants, because the waist area is already attached to these products. The fastening system typically includes a fastener such as tabs with ribbons, hook and loop fasteners, lockable fasteners such as tabs with grooves, buckles, buttons, latches and / or zwitterion fasteners, although other known fasteners are generally accepted. Normally there is a fastening zone in the front waist area to allow the fastener to be detachably fastened. Some exemplary surface fastening systems are disclosed in US 3,848,594, US 4,662,875, US 4,846,815, US 4,894,060, US 4,946,527, US 5,151,092 and US 5,221,274 to Buell. An example of a locking attachment system is disclosed in US Patent 6,432,098. The fastening system may also provide means for utilizing the product as disclosed in US Patent 4,963,140 to Robertson et al.

The fastening system may also include primary and secondary fastening systems as disclosed in US Patent 4,699,622 to minimize sliding of overlapping elements or better alignment as disclosed in US Patent 5,242,436, US 5,499,978, US 5.507.736 and US 5.591 .152.

Leg cuffs 34

The absorbent article may include a pair of leg cuffs and / or sealing cuffs 32. US Patent 3,860.003 describes a disposable diaper that provides removable leg openings with a side flap and one or more elastic elements to provide a flexible leg cuff (sealing cuff). In US Patent 4,808,178 and US 4,909,803 to Aziz et al. disposable diapers with "vertical" elasticized wings (leg cuffs) that improve leg support are described. US Patent 4,695,278 and US 4,795,454 to Lawson and Dragoo respectively describe disposable diapers with double cuffs, including sealing cuffs and leg cuffs. Balm can be applied to all or part of the leg cuff and / or sealing cuffs.

Leg protection cuffs 32 may be formed from a piece of material, typically a nonwoven fabric, which is partially bonded to the rest of the article, so that some of the material, leg protection cuffs, may be partially raised and separated from the plane defined by the cover layer when the article is unfolded

EP 2 813 201 flat as shown e.g. in Fig. 1. Leg protection cuffs can provide better retention of fluid and other body secretions at approximately the user's torso and legs. Leg protection cuffs at least partially protrude between the front edge and back edge of the diaper on opposite sides of the longitudinal axis and are at least present in the longitudinal position of the crotch point (C). Leg protection cuffs are limited by the proximal edge 64 connected to the rest of the article, typically the top layer and / or bottom layer, and the free end edge 66 that is intended to contact and form a seal with the user's skin. The leg protection cuffs are connected at the proximal edge 64 to the product base by means of a connection 65, which can for example be made by gluing, melting and pressure joining or a combination of known joining methods. The connection 65 on the proximal edge 64 may be continuous or discontinuous. The side of the connection 65 closest to the raised leg protector section 32 limits the proximal edge 64 of the vertical leg protector section.

Leg cuffs 32 can be integrated into the top or back layer or more typically formed from a separate material connected to the rest of the article. Typically, the leg protection cuff material may extend over the entire length of the diapers, but is "pinned" to the top layer towards the front edge and back edge of the article, so that in these parts the leg protection cuff material forms one surface with the top layer. Each leg cuff 34 may include one, two or more elastic elastic members 35 near the free end edge 66 to provide a better seal.

In addition to the leg protection cuffs 34, the article may include sealing cuffs 32 connected to the base of the absorbent article, in particular the top layer and / or the bottom layer, and may be positioned outside of the leg protection cuffs. Sealing cuffs can provide better sealing around the user's thighs. Typically, each sealing cuff includes one or more elastic elastic elements or an elastic element included in the base of the diaper, for example between the top layer and the bottom layer in the area of ​​the leg openings.

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Front and rear wings 46, 40

The absorbent article may include front wings 46 and rear wings 40 as is known in the art. The wings may form an integral part of the base, for example they may be formed of a top layer and / or a bottom layer as a side insert. Alternatively, as shown in Fig. 1 may be separate elements attached by means of gluing and / or hot stamping or pressure joining. Preferably, the rear wings 40 are stretchable, which facilitates the attachment of tabs 42 on the attachment zone 40 and maintenance of the diapers fastened with tape around the wearer's belt. Rear wings

40 they can also be elastic or stretchable to provide a more comfortable and contoured fit by properly preadapting the absorbent article to the wearer and maintaining such a fit throughout the entire wearing time, long after the absorbent article is loaded with body secretions, since the elastic wings allow expansion and contraction sides of the absorbent article.

Elastic waist

The absorbent article may also include at least one elastic waist (not shown) that helps in providing a better fit and protection. The elastic waistband is generally intended for elastic expansion and contraction for dynamic adjustment to the user's waistline. The elastic waistband preferably extends at least longitudinally outward from at least one waist edge of the absorbent body 28 and substantially forms at least part of the end edge of the absorbent article. Disposable diapers can be constructed in such a way that they have two elastic elements at the waist, one located in the front waist area and the other located in the back waist area. The elastic waist element can be constructed in a variety of ways including those described in patents US 4,515,595, US 4,710.189, US 5,151,092 and US 5,221,274.

Relationships between layers

Typically, adjacent layers and elements will be joined together using traditional joining methods, such as an adhesive layer by coating or gap spraying on all or part of the surface of a layer or by thermal bonding or pressure bonding or a combination of these methods. For the sake of clarity and readability, this connection has not been presented on

In the figures (except for the connection between the raised leg component 65 and the top layer 24), it should be considered that the connection between the product layers is present, unless expressly excluded. Adhesives are usually used to improve the adhesion of various layers, for example between the back layer and the liner cover. The adhesive may be any standard hot melt adhesive known in the art.

In the presence of an additional layer / collection layer 52, it may be advantageous if the collection layer is larger or at least as large as the fiber layer / distribution layer 54 in longitudinal and / or transverse dimensions. In this way, a spreading layer 54 can be deposited on the collecting layer. This simplifies handling, in particular if the collecting layer is made of a non-woven fabric which can be unrolled from a roll of raw material. The distribution layer may also be deposited directly on the upper surface of the cover of the absorbent body or other layer of the article. In addition, the collecting layer 52 larger than the spreading layer allows direct adhesion of the collecting layer to the storage cartridge (on larger surfaces). This can ensure a higher level of panel integrity and better fluid flow.

The absorbent body and in particular its absorbent material deposition area 8 may preferably be at least equal in size and length and preferably at least partially larger and / or longer than the fibrous layer. The reason for this is that the absorbent material in the insert can usually more effectively retain fluid and provide dryness benefits over a larger surface than the fibrous layer. The absorbent article may be provided with a rectangular layer of material

SAP and non-rectangular (formed) fibrous layer. The absorbent article may also be provided with a rectangular (unformed) fibrous layer and a rectangular layer of SAP material.

Product manufacturing method

Absorbent articles according to the present invention may be produced by any conventional method known in the art. In particular, the articles can be made by hand or produced on an industrial scale at high speed.

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Experimental settings

The values ​​presented in this document are measured by the methods below, unless otherwise specified. All measurements shall be made at a temperature of 21 ° C ± 2 ° C and a relative humidity of 50% ± 20%, unless otherwise stated. Unless otherwise specified, the description refers to the dry product. All samples should be stored under these conditions for at least 24 hours for alignment prior to testing, unless otherwise specified. All measurements should be repeated on at least 4 samples and the average value should be indicated, unless otherwise specified.

Centrifugal retention capacity (CRC)

In the CRC test, the liquid absorbed by the super absorbent polymer particles is measured for free swelling in conditions of excessive amount of liquid. CRC measurements are made according to the EDANA method WSP 241.2-05.

Dry absorbent core thickness test

This test can be used to measure the thickness of the absorbent body (before use, i.e. without liquid loading) in a standard manner.

Equipment: Mitutoyo manual caliper with resolution

0.01 mm - or equivalent.

Contact foot: Flat round foot with a diameter of 17.0 mm (± 0.2 mm). A round weight (e.g. a weight with a gap to facilitate application around the shaft of the instrument) can be attached to the foot to achieve the target weight. The total weight of the presser foot and added weight (including shaft) was selected to ensure that a pressure of

2.07 kPa (0.30 psi).

The caliper is mounted in such a way that the lower surface of the contact foot is in a horizontal plane, whereby the lower surface of the contact foot contacts the central part of the flat horizontal upper surface of the base plate approximately 20 x 25 cm. The caliper display is set to zero when the contact foot rests on the base plate.

Ruler: Calibrated metal ruler with graduations in mm.

Stopwatch: Accuracy level 1 second

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Sample preparation: The cartridge is conditioned for at least 24 hours as described above.

Measuring procedure: The insert is laid flat, while the underside, i.e. the side to be placed towards the top layer in the finished product, faces downwards. The measuring point (e.g. point C of the crotch corresponding to this point in the finished product) is carefully plotted on the top side of the cartridge, taking care not to squeeze or distort the cartridge.

The contact foot of the caliper is raised, while the insert is laid flat on the caliper base plate when the upper side of the insert is raised up, so after lowering the central part of the foot is at the marked measuring point.

The presser foot is gently lowered onto the product and released (make sure that the calibration value is "0" before starting the measurement). The thickness value is read to the nearest 0.01 mm, 10 seconds after releasing the foot.

The procedure is repeated for each measuring point. If there is a bend at the measuring point, the measurement is carried out at the closest point to that point, but without bends. Ten products are measured for a given product, the average thickness is calculated and reported to the nearest tenth of a mm.

Absorbent article thickness test

The thickness test of an absorbent article can be carried out as in the case of a dry absorbent core thickness test with the difference that the thickness of the finished absorbent article is measured instead of the thickness of the core. The measuring point can be the point of intersection of the longitudinal axis (80) and the transverse axis (90) of the absorbent article. If absorbent products are folded and / or packaged, the products to be measured should be spread out and / or removed from the center of the packaging. If the package contains more than 4 products, no two outermost products located on both sides of the package are used during the tests. If the packaging contains more than 4 but less than 14 products, more than one product packaging is required to perform the tests. If the packaging contains 14 or more products, only one product packaging is required for testing.

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If the package contains 4 or fewer products, all measurements from the packaging from multiple packages must be used for measurements. Thickness readings should be made 24 ± 1 hours after removing the product from the packaging, unfolding it and conditioning. The physical handling of the product must be minimal and limited only to the necessary sample preparation.

All flexible elements of the product that prevent the product from laying flat under the caliper foot should be cut off or removed. These may include leg cuffs or waist straps. If necessary, panties should be opened and cut along the side seams. To straighten bends / wrinkles, apply appropriate tension. Be careful not to touch and / or squeeze the measuring area.

Channel delamination test in immersion

The test is carried out on an absorbent body to determine the behavior of the connection of the body of the body in the event of an excess of saline as a function of time. The test is preferably carried out on an insulated absorbent body before it is incorporated into the finished product. The absorbent body can also be separated from the finished absorbent body. In this case, if necessary, you can use a spray freezer to facilitate removal of the absorbent body. Be careful to avoid damaging the cartridge, e.g. tears in the layers covering the insert. All cuffs, fastening elements, top layer, bottom layer or absorbent layers above and / or below the absorbent body are removed.

The areas of the cartridge sheath connection 27, which typically follow the approximate area (s) substantially free (free) of absorbent material, are marked on the body facing surface of the cartridge sheath by a permanent marker and the curvilinear length of these areas is measured. If the connections are broken, the full length is marked partly on the joints. The absorbent body is placed in a preferred container with a flat bottom, with the surface from the body side facing up. The container is large enough for the cartridge to lie completely flat and is about 6 cm deep. The container with the absorbent core is placed in an incubator or other preferred chamber with temperature control at 37 ± 0.5 ° C and allowed to reach thermal equilibrium. Sodium chloride solution

At a concentration of 0.90% by weight is prepared by dissolving the appropriate amount of pure sodium chloride in distilled water, the solution is heated to 37 ° C. The heated solution is quickly added to the container to a depth of about 4 cm, and after the liquid is added, the timer starts. After adding the liquid, the container is immediately covered with an adhesive film (e.g. Saran Wrap^®) to prevent excessive evaporation from the container, and the system is kept at 37 ± 0.5 ° C.

The absorbent body is observed through the adhesive film without interfering with the system every 5 minutes and the extent of delamination of all channels is recorded over time. The extent of delamination is the total length of any part or parts of the channel or channels where the top side of the cartridge housing is no longer attached to the bottom side of the cartridge housing in the channel area. Fractional delaminated length means the total length of delaminated channel divided by the total initial channel length before fluid addition. Percentage length of delaminated channel means the fractional length of delaminated channel multiplied by 100.

Experimental part

Absorbent body example 1:

The absorbent core tested in this example was similar to the one shown in Fig. 4. The pad contained SAP as the absorbent material, without cellulose fibers. The cartridge cover contained two substrates forming the top and bottom of the cartridge, an upper substrate forming a C-shaped cover along the longitudinal edges of the cartridge and flat front and back edges of the cartridge. The cartridge contained two curved areas free of absorbent material.

These areas were symmetrical about the longitudinal axis 80 'and had a projected length of about 227 mm, a width of about 8 mm and the shortest distance from each other 20 mm. The cartridge cover was further attached to it over substantially the entire length of the areas 26.

The absorbent body contained a total of 13.5 g SAP (e.g. Nippon Shokubai,

CA L598) applied in the deposition area 360 mm long and 110 mm wide (rectangular profile). SAP was positioned so that its basis weight was higher in the crotch area than in the front area and lower towards the posterior area. Transverse SAP profiling ("cross machine direction" or "CD" was not performed, except of course in the area

EP 2 813 201 channels that were free of absorbent material). The absorbent body was formed using SAP printing technology as disclosed in US2010 / 0051166A1, which connects two nonwoven substrates that support the SAP layer. The channels were created using a suitable printing drum determining the shape of the channels, further information on the creation of channels can be found in European Patent Application No. EP12174117.7 using SAP printing technology.

An additional adhesive (e.g. Fuller, HL 1358LO F ZP) was applied to the upper substrate 16 before applying the SAP layer and was applied to the crevices 41 with a width of 1 mm at a distance of 1 mm between the cracks along the entire length of the cartridge cover (390 mm) ) in a total amount of 0.128 g.

Each SAP layer had an adhesive with flexible microfibers (Fuller 1151) applied to its top to immobilize the SAP layer on the substrate. 0.211 g and 0.168 g of microfiber adhesive (from HB Fuller) were applied to the upper and lower SAP layers, respectively, the application area was 110 mm wide and 390 mm long on each SAP layer.

The insert shell was 390 mm long with two end flaps free of absorbent material 15 mm long at the rear and front edges of the absorbent body. The front and rear end seals were joined using adhesive gaps, the adhesive gaps were 30 mm long from the front end seal and 20 mm from the rear end seal. The composite width of the insert cover was 120 mm.

The upper substrate 16 was of 10 gsm, SMMS non-woven fabric, and the lower substrate 16 'was of 10 gsm, SMMS nonwoven. The upper substrate was cut to a length of 390 mm and a cutting width of 165 mm. The lower substrate had a cutting length of 390 mm and a cutting width of 130 mm. The upper substrate was C-wrapped around the lower substrate at the lateral edges of the insert, and the lateral edges of the lower layer were slightly formed upwards at the edge of the absorbent material of the insert, so that the overall width of the folded insert shell was about 120 mm. The C shield was durable due to the use of a folding adhesive applied between the substrates at 20 gsm, applied as a gap with a gap width of 4 mm and a length of 390 mm on each side of the cartridge.

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The two substrates were additionally connected together by channels. The bond was created by applying pressure and an additional adhesive with microfibers.

Example of the invention 2

The cartridge tested in this example was similar to Example 1, 5 with the difference that an additional adhesive NW1286 F ZP was used, e.g. HB Fuller.

Test results

For each absorbent core described above, two samples (X and Y) were tested according to the immersion channel dissection test to determine the percentage of connection of the sheath of the insert that will stratify as a function of time (in 5 m intervals). The opening size is presented as follows:

A - less than a third of the initial length of the cartridge sheath connection has delaminated;

B - from one third to two thirds of the initial length of the cartridge sheath connection has delaminated;

C - at least two-thirds of the initial length of the cartridge cover connection has delaminated.

<td>A sample</td><td colspan="2">1</td><td colspan="2">2</td>

<td>Sample Time (min) and</td><td>X1</td><td>Y1</td><td>X2</td><td>Y2</td>

<td>5</td><td>AND</td><td>AND</td><td>AND</td><td>AND</td>

<td>10</td><td>AND</td><td>AND</td><td>AND</td><td>AND</td>

<td>15</td><td>AND</td><td>AND</td><td>AND</td><td>B</td>

<td>20</td><td>AND</td><td>AND</td><td>B</td><td>B</td>

<td>25</td><td>AND</td><td>B</td><td>B</td><td>C</td>

<td>thirty</td><td>B</td><td>B</td><td>C</td><td>C</td>

<td>35</td><td>B</td><td>B</td><td>C</td><td>C</td>

<td>40</td><td>B</td><td>B</td><td>C</td><td>C</td>

<td>45</td><td>C</td><td>C</td><td>C</td><td>C</td>

<td>50</td><td>C</td><td>C</td><td>C</td><td>C</td>

<td>55</td><td>C</td><td>C</td><td>C</td><td>C</td>

<td>60</td><td>C</td><td>C</td><td>C</td><td>C</td>

As can be seen, the use of different adhesives provides a combination of a cartridge sheath that delaminates more slowly or quickly. Typically, increasing the amount of glue and / or using a stronger glue will provide

EP 2 813 201 stronger connections of the cartridge cover. Each of the absorbent bodies shown can be used in the absorbent body of the present invention.

Various

The dimensions and sizes disclosed herein should not be taken as strictly limited to the numerical values ​​cited herein. However, unless otherwise stated, each such dimension is intended to mean both a quoted value and a functionally equivalent range around such a value. For example, the dimension "40 mm" is intended to mean "about 40 mm".

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