Method for making an apertured web

The present invention relates to a method for producing a web having holes. Specifically, this method can be used for producing films having three-dimensional pores having the minimum aspect ratio, non-woven fabrics, and laminates having those pores.

The perforated web is used in a wide range of industrial and consumer products. For example, perforated films or perforated non-woven fabrics are known for use in disposable absorbent articles such as disposable diapers and women's hygiene articles such as sanitary napkins. Such articles typically have a fluid permeable topsheet, a fluid permeable breathable backsheet, and an absorbent core disposed between the topsheet and the backsheet. The perforated film can be made to form a fluid permeable topsheet and / or a fluid permeable breathable backsheet.

U.S. Patent Application No. 2006/0087053, published April 27, 2006, discloses a method for perforating the precursor web by moving the web material through the grip of a counter-rotating meshing roller. The first roller has ridges and grooves extending around it, and the second roller is tapered from the base to the tip, which is joined to the second roller at the base. It has multiple teeth. The base of the tooth has a cross-sectional length dimension that is greater than the cross-sectional width dimension. As the teeth of one roller mesh with the grooves on the other roller, holes are formed in the precursor web material. This process provides an efficient and cost-effective means for forming holes in the web, but the size and shape of the holes are the shape and orientation of the teeth of the second roller, as well as the length of forming the film. Limited by the orientation of the chain molecules. For example, an extruded film has a molecular orientation in which most long chain molecules are oriented mechanically, which in the case of an extruded film is the path the film follows throughout the extrusion process. The cross-sectional length of the teeth on the second roller of the counter-rotating roller is also aligned in the mechanical direction. As a result, when forming holes in the extruded film, this process tends to produce slit-like holes. Slits are acceptable for some applications, but holes such as oval holes are usually preferred.

<p><patcit num="1"><text>U.S. Patent Application No. 2006/0087053</text></patcit></p>

<p> Therefore, there is a need for a process to create holes in the film or non-woven laminate that can overcome the effects of molecular orientation of the film and produce holes that look like elliptical holes rather than slits. Is.</p>

<p> A method of drilling holes in the web is disclosed, and the holes produced in the web are more like elliptical holes rather than slits. The resulting web exhibits improved fluid acquisition capacity, compression resistance, and aesthetics. The method comprises providing a precursor web material having mechanical and machine lateral orientations. This precursor web has a molecular orientation with respect to the mechanical direction and the mechanical lateral direction. Later, the web is moved through a pair of meshing members that form holes in the web. The pair of meshing members includes a first member having a ridge and a groove and a second member having a plurality of teeth tapered from the base and the tip. The tooth is joined to a second member at its base. The base of the tooth has a cross-sectional length dimension that is greater than the cross-sectional width dimension. The teeth are oriented such that the cross-sectional length dimension of the tooth is arranged at an angle greater than zero with respect to the predominant molecular orientation of the web. Holes are formed in the precursor web material as the teeth of the second member engage the grooves of the first member. The holes have an aspect ratio of less than 4.0, preferably less than 3.0.</p><p> In one embodiment, the pair of meshing members comprises a pair of counter-rotating meshing rollers. The pair of meshing rollers includes a first roller having ridges and grooves extending in the circumferential direction and a second roller having teeth that mesh with the grooves of the first roller. The tooth is tapered from the base to the tip and is joined to the second roller at its base, which has a cross-sectional length dimension greater than the cross-sectional width dimension. The web material is moved through the grip of a counter-rotating meshing roller and holes are formed in the precursor web material as the teeth of one roller mesh with the grooves of the other roller.</p><p> An alternative method is to provide a precursor web material with a predominant molecular orientation in the machine direction and to produce a plastically deformed web with a modified molecular orientation with molecules aligned in the machine lateral direction. It includes a step of plastically deforming the precursor web in the lateral direction of the machine. The plastically deformed web is moved through a grip formed between the counter-rotating meshing rollers to form a hole in itself. The teeth of one roller are oriented towards the machine.</p><p> This method also has more open areas in the selective location of the web by limiting the plastic deformation of the web to selective locations prior to moving the web material through the grips of the counter-rotating meshing rollers. It can also be used to make holes.</p>

<figref num="1">Schematic of the process of the present invention.</figref><figref num="2">The perspective view of the apparatus of this invention.</figref><figref num="3">The cross-sectional view of the part of the apparatus shown in FIG.</figref><figref num="4">Schematic of another embodiment of the process and apparatus of the present invention.</figref><figref num="5">The perspective view of the part of the apparatus shown in FIG. 2 or FIG.</figref><figref num="6">An enlarged perspective view of a portion of the device shown in FIG.</figref><figref num="7">FIG. 2 is a perspective view of an alternative configuration of teeth of the device shown in FIG.</figref><figref num="8">The perspective view of the part of the apparatus shown in FIG.</figref><figref num="9">Top view of the portion of the device shown in FIG.</figref><figref num="10">Top view of the part of the device shown in FIG.</figref><figref num="11">A photograph of a greatly enlarged portion of a web with holes formed by the process of the present invention.</figref><figref num="12">FIG. 12 is a cross-sectional view of the web with the holes formed in FIG.</figref><figref num="13">A photograph of a greatly enlarged portion of a web with holes formed by the process of the present invention.</figref><figref num="14">FIG. 4 is a cross-sectional view of the web with the holes in FIG.</figref><figref num="15a">A photomicrograph of a hole formed in Sample 1 of Example 1.</figref><figref num="15b">A photomicrograph of a hole formed in Sample 2 of Example 1.</figref><figref num="16a">A photomicrograph of a hole formed in sample 3 of Example 2.</figref><figref num="16b">A photomicrograph of a hole formed in sample 4 of Example 2.</figref><figref num="16c">A photomicrograph of a hole formed in sample 5 of Example 2.</figref><figref num="16d">A photomicrograph of a hole formed in Sample 6 of Example 2.</figref><figref num="16e">A photomicrograph of a hole formed in sample 7 of Example 2.</figref><figref num="17">The cross-sectional view of the part of the gradual extension device.</figref><figref num="18a">A photomicrograph of a hole formed in Sample 8 of Example 4.</figref><figref num="18b">A photomicrograph of a hole formed in sample 9 of Example 4.</figref><figref num="18c">A photomicrograph of a hole formed in sample 10 of Example 4.</figref><figref num="18d">A photomicrograph of a hole formed in sample 11 of Example 4.</figref><figref num="19a">A photomicrograph of a hole formed in sample 12 of Example 5.</figref><figref num="19b">A photomicrograph of a hole formed in sample 13 of Example 5.</figref><figref num="20A">Schematic of various alternative laminate web configurations.</figref><figref num="20B">Schematic of various alternative laminate web configurations.</figref><figref num="20C">Schematic of various alternative laminate web configurations.</figref>

Definition of terms: As used herein and in the claims, the term "contains" is inclusive or non-limiting and does not exclude additional elements, components, or method steps not listed.

"Machine direction" or "MD" is the direction parallel to the direction of movement of the web as it moves during the manufacturing process. Direction within ± 45 degrees of MD is considered mechanical direction.

"Machine lateral" or "CD" is the direction in a plane that is substantially perpendicular to the MD and is generally defined by the web. Direction within 45 degrees of the transverse direction is considered to be the transverse direction.

As used herein, the term "driving" means either process, in which the tensile strain created by the meshing teeth and grooves stretches or stretches the intermediate web area. Such processes have been found to be useful in the production of a large number of articles, including breathable films, stretchable composites, pored materials, and non-flat materials. In the case of non-woven webs, stretching can cause fiber reorientation, loss of basis weight, and / or controlled fiber breakdown within the intermediate web area. A common driving method is, for example, a process known in the art as ring rolling.

As used herein, the term "driving member" means a device that includes teeth and grooves to perform driving.

As used herein, the term "deformation zone" means an area in which the teeth and grooves of opposing drive members mesh to cause drive.

As used herein, the term "path length" means the length of the deformation zone formed by the meshing teeth and grooves of the opposing drive members.

As used herein, "engagement depth" means the degree to which the meshing teeth and grooves of opposing drive members extend into each other.

As used herein, the term "nonwoven web" has fibers that are usually randomly oriented, rather than in a repeating pattern such as in a woven or woven fabric. Does not refer to a web with individual fiber or thread structures. Nonwoven webs or fabrics are formed by a number of processes, such as melt blow processes, spunbonding processes, hydroentangled rings, and card web bonding processes that include carding thermal bonding. The basis weight of non-woven fabric is usually expressed in grams per square meter (gsm). The basis weight of the laminated web is the combined basis weight of the component layer and any other additional component. Fiber diameter is usually expressed in micrometers, but fiber size can also be expressed in denier, which is a unit of weight per unit length of fiber. The basis weight of the laminated web suitable for use in the present invention can be in the range of 6gsm to 400gsm, depending on the end use of the web. For example, when used as a hand towel, both the first and second webs can be non-woven webs having a basis weight of 18 gsm to 500 gsm.

The constituent fibers of the non-woven web can be polymeric fibers and can be monocomponent, bicomponent, and / or two constituent, non-circular (eg, capillary channel fibers), and 0.1-500 micrometers. Can have major cross-sectional dimensions in the range of (eg, diameter in the case of round fibers). The constituent fibers of the non-woven web are also such as chemistry (eg PE and PP), constituents (mono- and bis-), denier (microdenier and&gt; 20 denier), shape (ie, capillary and round), etc. It may be a mixture of different fiber types with different characteristics. The constituent fibers can range from about 0.1 denier to about 100 denier.

As used herein, a "spun bond fiber" extrudes a thermoplastic material melted from a plurality of fine, usually circular capillaries of a spinneret as filaments, and then rapidly reduces the diameter of the extruded filaments. Refers to fibers with a relatively small diameter formed by making them. Spunbond fibers are generally non-sticky when deposited on the collection surface. Spunbond fibers are generally continuous and have an average diameter (from at least 10 samples) greater than 7 micrometers, more specifically about 10-40 micrometers.

As used herein, the term "melt blowing" refers to a fused thermoplastic material passing through a plurality of fine, usually circular mold capillaries, usually heated and converging fast gas (eg, air). It refers to the process by which fibers are formed by extruding into a stream as molten yarn or filament and thinning the filament of the thermoplastic material melted by this gas stream to reduce its diameter, with a microdiameter. It may be the fiber diameter. The melt-blown fibers are then carried by a high-speed gas stream and deposited on the collection surface, often still sticky, forming a randomly dispersed web of melt-blown fibers. Melt blown fibers are microfibers that may or may not be continuous and have an average diameter of generally less than 10 micrometers.

As used herein, the term "polymer" generally includes homopolymers, copolymers (such as block, graft, random, and alternating copolymers), terpolymers, and mixtures and modifications thereof. Not limited to these. Furthermore, unless otherwise specified, the term "polymer" includes any possible geometrical composition of the material. Its configurations include, but are not limited to, isotactics, atactics, syndiotactics, and random symmetry.

As used herein, the term "monocomponent" fiber refers to a fiber formed from one or more extruders using only one polymer. This does not mean excluding fibers with a small amount of additives, although they are made from one polymer, due to coloration, antistatic properties, lubricity, hydrophilicity, etc. These additives, such as titanium dioxide for coloring, are generally present in an amount of less than about 5% by weight, more generally less than about 2% by weight.

As used herein, the term "bicomponent" fiber refers to a fiber formed from at least two different polymers that are extruded from separate extruders but spun together to form one fiber. Bicomponent fibers are also sometimes referred to as composite fibers or multicomponent fibers. The polymers are located in different areas that are located substantially consistently across the cross section of the bicomponent fiber and extend continuously along the length of the bicomponent fiber. The shape of such bicomponent fibers may be, for example, a sheath / core arrangement in which one polymer is surrounded by another polymer, or in a side-by-side arrangement, pie-type arrangement, or "sea-island-type" arrangement. There may be.

As used herein, the term "two-constituent fiber" refers to a fiber formed from at least two polymers that are extruded as a blend from the same extruder. The two constituent fibers do not have various polymer constituents arranged in different areas that are located relatively consistently across the cross-sectional area of the fiber, and the various polymers are usually continuous along the entire length of the fiber. Instead, they usually form fibers that start and end at random. Two-constituent fibers are also sometimes referred to as multi-component fibers.

As used herein, the term "non-round fiber" describes a fiber having a non-round cross section and includes "molded fiber" and "capillary channel fiber". Such fibers can be solid or hollow, they can be trilobal, delta-shaped, and may have capillary channels on the outer surface. The capillary channel can have a variety of cross-sectional shapes such as "U", "H", "C", and "V". One preferred capillary channel fiber is T-401, a so-called 4DG fiber available from Fiber Innovation Technologies (Johnson City, TN). The T-401 fiber is polyethylene terephthalate (PET polyester).

As used herein, the term "molecular orientation" describes the degree to which a polymer chain or crystal is located along a particular direction.

As used herein, the term "dominant molecular orientation" describes the degree to which most of the polymer chains are located along a particular direction.

As used herein, the term "plastic deformation" is the deformation that remains in the material after the load that causes the deformation has been removed. Plastic deformation is a permanent deformation that exceeds the elastic limit of the material.

For all numerical ranges disclosed herein, any maximum numerical limitation described throughout this specification shall express any numerical limitation smaller than that, such a small numerical limitation expressly herein. It should be understood to include as if it were. In addition, any minimum numerical limitation described throughout this specification includes any larger numerical limitation as if such a large numerical limitation was explicitly stated herein. Moreover, every numerical range described throughout this specification includes any narrower numerical range that falls within such a wider numerical range, as well as each individual number within that numerical range. Above all, the narrower numerical range and individual numerical values are all included as if they were explicitly described herein.

The present invention describes methods and devices used to make perforated webs. The web in which the pores are formed can be a film or a laminate in which the pores are formed, which includes a film and a non-woven fabric. The pores can include micropores and macropores, the former being substantially invisible to the naked eye of the observer from a distance of about 1 meter under normal indoor lighting, the latter being visible under such conditions. is there. Micropores and / or other embossing or non-smoothing processing can be formed prior to processing by the apparatus of the present invention. The perforated web can be disposable absorbent items such as bandages, wrapping materials, incontinence tools, diapers, sanitary napkins, panty liners, tampons, and hemorrhoid treatment pads, as well as, for example, floor cleaning sheets, body wipes, laundry sheets. Can be used for other consumer products such as. In addition, the web of the present invention can also be used as a perforated web for automotive, agricultural, electrical, or industrial applications.

A schematic diagram of one device of the present invention is shown in FIG. The precursor web 20 moves the forming apparatus 150 in the mechanical direction (MD), and the holes 6 are formed to generate the pore-formed web 1. The precursor web 20 is a feed roll 152 (or a plurality of feed rolls required in the case of a composite web laminate), or any other feed means known in the art, such as a festoon web. Can be supplied from. In one embodiment, the precursor web 20 can be supplied directly from a web making device such as a polymeric film extruder. After formation, the perforated web 1 can be wound onto a feed roll 160 for storage and further processing as a component of other products. Alternatively, the perforated web 1 may be sent directly to a further post-process, including conversion work for incorporation into a finished product such as a disposable absorbent product.

As shown in FIG. 1, the perforated web 1 can be formed from a generally flat two-dimensional precursor web 20 having a first surface 12 and a second surface 14. The precursor web 20 may be a polymer film or a laminate of a polymer film and a non-woven fabric web. The first surface 12 corresponds to the first side surface of the precursor web 20 and the first side surface of the perforated web 1. The second surface 14 corresponds to the second side surface of the precursor web 20 and the second side surface of the perforated web 1. In general, the term "side" is used herein in a general way to describe the two main surfaces of a generally two-dimensional web, such as film. Of course, in composite or laminated structures, the first surface 12 of the pored web 1 is the first side of one of the outermost layers or plies, and the second surface 14 is the most of the other. The second side of the outer layer or ply.

The precursor web 20 can be a polymeric film web. In one embodiment, the precursor web 20 may be a polymeric web suitable for use as a topsheet for disposable absorbent products known in the art. The polymeric film web can be deformable. As used herein, a deformable material describes a material that substantially retains its newly formed morphology when stretched beyond its elastic limits. Such deformable materials may be chemically homogeneous or inhomogeneous, such as homopolymers and polymer blends, and structurally homogeneous, such as flat sheets or laminates. May be heterogeneous, or may be a combination of any of these materials. The process of the present invention is used in the formation of materials containing polymeric films. Such materials include single polymer films or laminates containing polymer films and other materials such as non-woven fabrics.

The deformable polymeric film web utilized in the process of the present invention is the transformation temperature at which changes in the molecular structure of the solid state of the material occur, such as changes in the crystalline structure or changes from the solid to the molten state. Can have a range. As a result, certain physical properties of the material change substantially in the above transformation temperature range. In thermoplastic semi-crystalline films, the transformation temperature range is the glass transition temperature range of the film, or above, where the polymer becomes rubbery and can be elastically or plastically deformed without breaking. It may be in the melting temperature range of the film, where the film is in a molten state and loses virtually all previous thermomechanical history.

Polymer film webs can include thermoplastic polymers with characteristic rheological properties that depend on the composition and temperature of the polymer. At temperatures below the glass transition temperature, such thermoplastic polymers can be fairly stiff, rigid and often brittle. At temperatures below the glass transition temperature, the molecule is in a tightly anchored position. At temperatures above the glass transition temperature but below the melting temperature range, the thermoplastic polymer exhibits viscoelasticity. In this temperature range, thermoplastic materials generally have some degree of crystallinity, are generally flexible, and are deformable to some extent under force. The deformability of such a thermoplastic substance is determined by the deformation rate, the amount of deformation (dimensional amount), the length of time for deformation, and the temperature. In one embodiment, the process of the present invention can be utilized to form a material containing a thermoplastic polymer, which is a particularly thermoplastic film within this viscous temperature range.

The polymeric film web can contain a certain amount of ductility. Ductility, as used herein, is the amount of permanent and irreparable plastic strain that occurs when a material is deformed before it breaks (ruptures, breaks, or separates). Ductility depends on the rate of strain applied to the material. The materials formed in the process of the present invention can have a minimum ductility of at least about 10%, or at least about 50%, or at least about 100%, or at least about 200%, or at least about 500%.

The polymeric film web utilized in the present invention can include materials that are usually extruded or cast as films such as polyolefins, nylons, polyesters and the like. Such films can be thermoplastic materials such as polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, and copolymers and blends containing a significant proportion of these materials. Such a film can be treated with a surface modifier to impart hydrophilic or hydrophobic properties, such as imparting a Lotus effect. The polymeric film web may be a single-layer or multi-layer flat film. As described below, the polymeric film web can be unsmoothed, embossed, or otherwise altered from a completely flat and planar configuration.

The physical properties of the polymer film, especially the elastic modulus, depend on the molecular orientation of the polymer defined above as the degree to which the polymer chains are located along a particular direction. The molecular orientation of the film can be determined by ASTM's D2732-03 method. The test method determines the degree of strain-free linear thermal shrinkage at a given sample temperature of a plastic film and sheet with a thickness of 0.76 mm (0.030 inch) or less. A film sample having a predominant molecular orientation shrinks mainly in the direction of the predominant molecular orientation, whereas the degree of shrinkage in the direction perpendicular to it is smaller.

The biaxially oriented polymeric film has a substantially random orientation with respect to MD and CD. "Substantially random molecular orientation" means that due to conditions during film processing, the amount of long chain molecules oriented to MD is not significantly higher than that in CD. In other words, the number of long-chain molecules in MD and the number of long-chain molecules in CD are about the same. As a result, films with random molecular orientations can exhibit similar properties such as modulus, MD, and CD. The blown film is an example of a biaxially oriented polymer film. In contrast, films with a predominant molecular orientation have more long chain molecules oriented in a particular direction. For example, an extruded film can have more long chain molecules oriented towards MD than CD. The cast film is an example of a film having a molecular orientation predominantly in MD. The molecular orientation of the polymeric film can be changed by heating and / or plastically deforming the film. For example, a film having a molecular orientation predominantly in MD can be strained to plastically deform into CD and change the orientation of the long-chain polymer to be a biaxial or CD-oriented polymer film.

The precursor web 20 may be a composite or laminate of two or more precursor webs, and may include, for example, a combination of a polymeric film and a non-woven fabric. Nonwoven webs or fabrics have been formed from many known processes such as air laying processes, melt blowing processes, spunbonding processes, water flow confounding processes, spunlacing processes, and card web bonding processes. You may also utilize multi-layer webs such as spunbond-melt blown-spanbond (SMS) webs and similar ones (eg SMMS, SSMS) made by a multi-beam spunbond process. Each component (ie, a spunbond or meltblown component) does not have to be the same polymer. Therefore, on the SMS web, the spunbond and meltblown layers do not have to contain the same polymer.

The constituent fibers of the non-woven web can be polymer fibers, monocomponents, bicomponents, and / or two constituent fibers, hollow fibers, non-rounded fibers (eg, molded (eg, three-leaf) fibers, or capillary tracts. Fibers) and major cross-sectional dimensions in the range of 0.1-500 micrometer in 1 micrometer increments (eg, round fiber diameter, elliptical fiber major axis, irregular longest linear dimension) ) Can have.

The precursor web 20 can be preheated by means known in the art, such as by radiant heating, forced air heating, convection heating, or by heating the entire oil-heated roller. Precursor web 20 may be pre-printed with signs, designs, logos, or other visible or invisible print patterns. For example, the design and color can be printed by means known in the art such as inkjet printing, gravure printing, flexographic printing, or offset printing to change the color of at least a portion of the precursor web 20. In addition to printing, the precursor web 20 may be treated with a coating such as a surfactant, lotion, adhesive or the like. Treatment of the precursor web 20 can be accomplished by means known in the art, such as spraying, slot coating, extrusion, or otherwise coating one or both surfaces.

As the feed roll 152 rotates in the direction indicated by the arrow in FIG. 1, the precursor web 20 rolls over or around any of the various idler rollers, tension control rollers, etc. (none of these shown). Means known in the art, including, move in the mechanical direction to the grip 116 formed from the pair of counter-rotating meshing rolls 102 and 104. The paired meshing rolls 102 and 104 act to form holes in the web 20 to form the holed web 1. The meshing rolls 102 and 104 are shown in more detail with reference to FIG.

With reference to FIG. 2, the portion of the molding apparatus 150 for making a hole in the hole-formed web 1 is shown in more detail. This portion of apparatus 150 is shown in FIG. 2 as forming apparatus 100, each comprising a pair of steel meshing rolls 102 and 104 rotating around axis A, axis A being parallel and coplanar. It is in. The molding apparatus 100 can be designed such that the precursor web 20 remains on the roll 104 over a constant rotation angle, as shown in detail with respect to FIG. It shows what happens in principle as it travels straight through the grip 116 on the forming apparatus 100 and exits as a perforated web 1. Thus, FIG. 2 shows the web 1 forming a hole that enters and exits straight into the grip 116, but before (with respect to precursor 20) or after (with respect to the precursor 20) the web 1 that formed the hole. With respect to), it is also possible to partially wrap the precursor web 20 or the perforated web 1 around either roll 102 or 104 over a predetermined rotation angle. For example, after exiting the grip 116, the web 1 having a hole formed over a predetermined rotation angle is guided to be wound around the roll 104, and the hole is stationary on the tooth 110 of the roll 104 as shown in FIG. It can be left "fitted".

The rollers 102 and 104 may be made of steel or aluminum. In one embodiment, the rollers can be made of stainless steel. In general, rollers 102 and 104 can be made of corrosion and wear resistant steel.

The roll 102 can include a plurality of ridges 106 and corresponding grooves 108 that can uninterruptedly surround and extend the entire perimeter of the roll 102. In some embodiments, in the perforated web 1, depending on what type of pattern is desired, the roll 102 may have some or all of the ridges 106 that are not continuous in the circumferential direction, with cracks or gaps. Can include a raised portion 106 that has been partially removed, for example by etching, milling, or other machining. The crevices or gaps may be arranged to form a pattern that includes a simple geometric pattern such as a circle or rhombus, but may also include a complex pattern such as a logo and trademark. In one embodiment, the roll 102 can have teeth similar to the teeth 110 of the roll 104, which will be described in detail later. In this way, it is possible to have three-dimensional holes having outwardly extending portions on both sides of the hole-formed web 1. In addition to the holes, various off-plane macro areas of the holes in Web 1 can be created, including macro patterns of embossed textures depicting logos and / or designs. In an alternative embodiment, the outer surface of the roll 102 may include a rubber-like brush or elastic material that allows the teeth on the connecting roll 104 to penetrate the grip formed between the two rolls. it can.

Alternatively, instead of roll 102, a brush conveyor as disclosed in US Pat. No. 5,802,682 issued to Jourde et al. On September 8, 1998 may be used. In this embodiment, the brush conveyors are arranged so as to bond with the teeth on the rolling 104 to be coupled so that the teeth penetrate the brush at the grip formed between the roll 104 and the brush conveyor. it can.

The roll 104 is similar to the roll 102, but has no ridges that can extend seamlessly over the entire circumference, and the roll 104 extends in a spaced relationship around at least a portion of the roll 104. It comprises a plurality of rows of ridges extending in the peripheral direction, modified to form a row of teeth 110 that are spaced apart in the peripheral direction. The individual rows of teeth 110 of the roll 104 are separated by the corresponding grooves 112. During operation, the rolls 102 and 104 mesh so that the raised portion 106 of the roll 102 extends into the groove 112 of the roll 104 and the teeth 110 of the roll 104 extend into the groove 108 of the roll 102. The bite is shown in great detail within the cross-sectional view of FIG. 7, which is discussed below. Rolls 102 and / or 104 can be heated by means known in the art, such as by incorporating a hot oil-filled roller or an electric heating roller. Alternatively, both or either of the rolls may be heated by surface convection or by surface radiation.

The teeth 110 can be joined to the rollers 104. "Joining" means that the teeth can be joined and attached by welding, compression fitting, or otherwise. However, "joining" also includes an integral attachment, as in the case of a tooth machined by removing excess material from the roller 104. The position where the tooth 110 is joined to the roller 104 is its base. At any cross-sectional position parallel to the base, each tooth can have a non-round cross-sectional area. In the peripheral direction, the cross-sectional length of the cross-section area (corresponding to the tooth length as shown below) is at least 2 of the width of the cross-section measured perpendicular to its length dimension at the center of the cross-section area. It is double. In an alternative embodiment, the tooth may comprise a cylindrical, rectangular, or other shape of pin that depends on the corresponding desired hole shape.

A cross section of the portion of the meshing rolls 102 and 104 including the raised portion 106 and the representative tooth 110 is shown in FIG. As shown, the tooth 110 is tooth height TH (note that TH can also be applied to the height of the ridge 106, in a preferred embodiment the height of the tooth and the height of the ridge are equal), and It has an interdental spacing (or ridge spacing) indicated by pitch P. As shown, the engagement depth (DOE) E is a measurement of the degree of engagement of the rolls 102 and 104, measured from the tip of the raised portion 106 to the tip of the tooth 110. The engagement depth E, tooth height TH, and pitch P can be varied as desired, depending on the properties of the precursor web 20 of the present invention and the desired characteristics of the perforated web 1. For example, in general, in order to increase the density of the volcanic structure 8 or hole 6 of the web 1, the pitch should be smaller and the tooth cross-sectional length TL and as described below. The tooth spacing TD should also be smaller.

It is also conceivable that the size, shape, orientation, and spacing of the teeth 110 may be varied along the periphery and width of the roll 104 to alter the properties and characteristics of the perforated web 1.

In addition, substances such as lotions, inks, surfactants, etc. are sprayed, coated, slot coated, extruded, or otherwise applied to the perforated web 1 before or after entering the grip 116. can do. Any process known in the art for the application of such processing can be utilized.

In one embodiment, the perforated web 1 can be formed by processing the precursor web 20 through an apparatus 200 as shown in FIG. The multi-roller array of device 200 is designed to provide a defined dwell time at which the perforated web 1 remains in contact with the toothed roller 104 over a defined angle of rotation. The angle of rotation can be optimized depending on the type of film, the temperature of the rollers, and the speed of movement of the web, but in general, the angle of winding depends, at least in part, on the relative size of the rollers to be bonded. It can be at least 10 degrees and up to about 270 degrees or more. As shown, as described for the roller 102 of the apparatus 150 in FIG. 1 above, the precursor 20 is around various guide rollers and tension members (not shown) and on the roll 102A to guide the roller 105. Can lead to the top. Roller 102A may be heated to aid in the formation of volcanic structures 8 and holes 6. In one embodiment, the roller 102 can be heated to about 93 ° C (200 ° F).

As shown in FIG. 4, the precursor web 20 enters the grip portion 116A formed by the mutual engagement of the meshing rollers 104 and 102A. The roller 104 of the device 200 can be a toothed roller as described above with respect to the device 150 of FIG. As the precursor web 20 passes through the grip 116A, the teeth 110 on the roller 104 press through the precursor web 20 in and / or through to form a volcanic structure 8 and a hole 6. .. The holed web 1 then maintains a fixed contact with the rotating roller 104 until it reaches the grip 116B formed by the mutual engagement of the roller 104 and the roller 102B. The roller 102B can have ridges and grooves as described for the roller 102 of device 150 of FIG. 1 above.

As it exits the grip 116B, the perforated web 1 is guided away from the roller 104 onto the roller 102B, crossing the various guide rollers 105 as needed, and then further process, transport, or industrial product. Taken up for placement for incorporation into. In one embodiment, the perforated web 1 is sent to the manufacturing process for a sanitary napkin and the perforated web 1 is fed to the process as a topsheet and other configurations such as backsheet webs. It is joined to the element, cut into the final shape, packaged and shipped to the retail channel. In another embodiment, the web is sent to the process of manufacturing the diaper product, and the perforated web 1 is fed to the process as a backsheet and joined with other components such as a topsheet.

If the perforated web 1 tends to stick to the teeth 110 when peeled off the roller 104, a variety of processing aids can be added as needed. For example, anti-stick treatments such as silicone or fluorocarbon can be added. Various lubricants, surfactants, or other processing aids can be added to the precursor web 20 or roller 104. Other ways to help remove the web from the rollers include air knives or brushing. In one embodiment, the roller 104 can have an internal chamber and means to bring positive air pressure onto the roller 102B at the point of web removal. In general, the control of movement from roller 104 to roller 102B is affected by web velocity, relative roller velocity (ie, the tangential velocity of roller 104 and roller 102B), web tension, and relative friction coefficient. Each of these parameters can be modified as known to those of skill in the art to ensure the desired movement of the perforated web 1 to roller 102B.

The benefit of having a device as shown in FIG. 4 is that the perforated web 1 is in contact with the teeth 110 of the roller 104 to extend the "nesting" time. In this way, the volcanic structure 8 and the hole 6 will have additional time to cure and are more likely to maintain their three-dimensional configuration after being removed from the roller 104. Without being bound by theory, by adjusting the temperature around the rollers 104, the temperatures of the rollers 102A, 104, and / or 102B, and the coefficient of friction of the rollers, this longer dwell time was utilized to form the holes in the web. It is believed that the line speed at which 1 can be processed can be increased to create a permanent three-dimensional volcanic structure 8. The temperatures of the rollers 102A, 104, and / or 102B may all be the same or may be different. For example, rollers 102A and 104 can be heated while keeping the rollers 102B below room temperature. In addition, the speeds of the various rollers may be maintained at the same speed, or different speeds may be established for each roller.

Care must be taken to consider thermal expansion when heating either the rollers of device 150 or 200 as described above. In one embodiment, the dimensions shown in FIG. 3 and the dimensions described herein are dimensions at operating temperature, and the ridges, grooves, and / or tooth dimensions take thermal expansion into account. Is machined.

FIG. 5 shows a portion of an embodiment of a roller 104 having a plurality of teeth 110 that is useful for making a perforated web 1. FIG. 6 is an enlarged view of the tooth 110 shown in FIG. As shown in FIG. 6, each tooth 110 has a base 111, a tooth tip 112, a leading edge LE, and a trailing edge TE. The tooth tip 112 is generally pointed, bluntly pointed, or otherwise shaped to stretch and / or puncture the precursor web 20. The teeth 110 can have a generally flat blade-like shape. That is, the tooth 110 can have an elongated cross-sectional shape that is generally non-circular, with one side extended, as opposed to a round pin-like shape that has a generally circular cross section. For example, at its base 111, the cross section of the tooth 110 is at least two, or at least about three, or at least about five, or at least about seven, or at least about 10, or more TL / TW. It may have a tooth length TL and a tooth width TW exhibiting a tooth aspect ratio AR. In one embodiment, the cross-sectional dimension aspect ratio AR remains substantially constant with respect to tooth height.

In one embodiment of the roller 104, the tooth 110 has a uniform cross-sectional length dimension TL of about 1.25 mm, which is approximately measured from the front edge LE to the trailing edge TE at the base 111 of the tooth 110, and at the base It may have a tooth cross-sectional width TW of about 0.3 mm, measured approximately perpendicular to the peripheral length dimension. The teeth can be evenly spaced from each other in the circumferential direction at a distance TD of about 1.5 mm. To create a web 1 from the precursor web 20 with soft fibrous three-dimensional pores having a basis weight in the range of about 5 gsm to about 200 gsm, the teeth 110 of the roll 104 are about 0.5 mm to about 3 mm. Length TL in the range of about 0.3 mm to about 1 mm, tooth width TW of about 0.3 mm to about 1 mm, interval TD of about 0.5 mm to about 3 mm, tooth height TH in the range of about 0.5 mm to about 10 mm, and about 1 mm (0.040 inch) to 2.54 It can have a pitch P of mm (0.100 inches). The engagement depth E can be from about 0.5 mm to about 5 mm (up to near tooth height TH).

Naturally, the engagement depth E, pitch P, tooth height TH, spacing TD, and tooth cross-sectional length TL are the desired size, spacing, and area density of the holes 6 (per unit area of the web 1 forming the holes). Each of them may be changed independently of each other in order to achieve (the number of holes 6). For example, to make pore-formed films and non-woven fabrics suitable for use in sanitary napkins and other absorbent articles, the cross-sectional length TL of the teeth at the base is from about 2.032 mm to about 3.81 mm. The tooth width TW can be in the range of about 0.508 mm to about 1.27 mm, the tooth spacing TD can be in the range of about 1.0 mm to about 1.94 mm, and the pitch P can be in the range of about 1.106 mm. It can be in the range of about 2.54 mm, and the tooth height TH can be from about 2.032 mm to about 6.858 mm. The engagement depth E can be from about 0.5 mm to about 5 mm. The radius of curvature R of the tooth tip 112 can be 0.001 mm to about 0.009 mm. Without being bound by theory, the tooth length TL at the base can range from about 0.254 mm to about 12.7 mm and the tooth width TW can range from about 0.254 mm to about 5.08 mm. , The tooth spacing TD can be in the range of about 0.0 mm to about 25.4 mm (or more), the pitch P can be in the range of about 1.106 mm to about 7.62 mm, and the tooth height TH can be in the range of 0.254 mm to about 0.254 mm. It is believed that it can be in the range of 18 mm and the depth of engagement E can be in the range of 0.254 mm to about 6.35 mm. For each of the disclosed ranges, it is disclosed herein that the dimensions can be changed in increments of 0.001 mm within the range of minimum to maximum dimensions, and this disclosure is in the range limits and in between. It is disclosed herein that the dimensions are taught in 0.001 mm increments (excluding the radius of curvature R disclosed as the increments vary in 0.0001 mm increments).

It is believed that it is possible to use other dimensions in the methods and devices of the present invention without being bound by theory and consistent with the currently pending tool design. For example, the tooth length TL at the base can range from about 0.254 mm to about 12.7 mm and can include 4.42 mm, 4.572 mm, and about 5.56 mm, and the tooth width TW from about 0.254 mm. It can be in the range of about 5.08 mm, can include 1.78 mm, the tooth spacing TD can be in the range of about 0.0 mm to about 25.4 mm, can include 2.032 mm, and the pitch P can be about 1.106 mm. The tooth height TH can be in the range of 0.254 mm to about 18 mm, can include 5.08 mm, and the engagement depth E can be in the range of 0.254 mm to about 6.35 mm. Can be. The radius of curvature can range from about 0.00 mm to about 6.35 mm. For each of the disclosed ranges, it is disclosed herein that the dimensions can be changed in increments of 0.001 mm within the range of minimum to maximum dimensions, and this disclosure is in the range limits and in between. It is disclosed herein that the dimensions are taught in 0.001 mm increments (excluding the radius of curvature R disclosed as the increments vary in 0.0001 mm increments).

In one embodiment, LEs and TEs can be described as shark tooth-like shapes as a whole cone or, to create the volcanic structure 8 and / or hole 6 of the perforated web 1. It must be formed in a tapered shape toward the cone-shaped points. As shown in FIG. 10, an overall pointed pyramidal shark tooth profile can have six sides 114, each side being triangular as a whole. The vertices of the two sides form the leading edge LE and the vertices of the two sides form the trailing edge TE of the tooth 110. The apex of the tip or trailing edge may be relatively sharp or machined to have a round radius of curvature. The radius of curvature of the tip of the tooth can be 0.013 cm (0.005 inch).

Holes may be made using other tooth shapes. For example, as shown in FIG. 7, the overall pyramidal shape shown in FIG. 5 may be truncated to remove the sharpness of the tip 112. The incision can be made at a predetermined distance from the base 111 so that a generally flat area 120 is created at the distal end of the tooth 110. The generally flat region 120 can have a surface shape corresponding to the cross-sectional shape of the tooth 110. Therefore, the generally flat region 120 may be elongated, i.e., it may have an aspect ratio AR corresponding to a length dimension greater than the width dimension and an aspect ratio of the teeth 110. In one embodiment, the flat region 120 can generally transition to the side 114 with sharp vertices, or the transition can result in a radius of curvature, resulting in a smooth, round, flat tooth tip. ..

In another embodiment, as shown in FIG. 8, the tooth 110 can have at least one edge extending approximately perpendicular to the surface of the roller 104. As shown in the partial perspective view of the roller 104 in FIG. 8, for example, a tooth resembling a shark fin faces an angled leading edge LE and a tooth tip 112 towards the tooth tip 112. It can have a trailing edge TL that extends approximately vertically from the base 111. In another embodiment, the teeth 110 can have the same shape, but the anterior and posterior edges are reversed, so the generally vertical edge is the anterior edge.

FIG. 9 is a top view of the portion of the roller 104 shown in FIG. The embodiments shown in the figure show various dimensions and include the angles formed by the side surfaces 114 forming the leading and trailing edges. Similarly, FIG. 10 shows the details of the tooth shown in FIG. 8 and shows typical dimensions. In general, the dimensions in the figure are currently considered to be useful in making 3D molded films useful as topsheets for disposable absorbent articles, but all dimensions are the desired pore density of the precursor web 20. It may be changed as needed depending on the spacing, size, and web type.

Without being bound by theory, having a relatively sharp tip on the tooth 110 allows the tooth 110 to "cleanly", i.e. locally and clearly, puncture the precursor web 20. The resulting perforated web 1 can be described primarily as "perforated" rather than predominantly "embossed". In one embodiment, the puncture of the precursor web 20 is a clean puncture that hardly deforms the web 20, so that the resulting web is effectively a two-dimensional perforated web.

Film with holes Molded film web 1 with two typical three-dimensional holes formed is shown in the micrographs of FIGS. 11-14. FIG. 11 shows a portion of web 1 with three-dimensional holes made from a generally flat polyethylene film precursor web 20 having a basis weight of about 25 grams per square meter. The hole 6 shown in FIG. 11 extends to permanently deform the precursor web 20 to form a plurality of separate isolated volcanic structures 8 extending outward from the first side surface 12. It was formed by the action of teeth 110 on a heated roll 104 with precursor web 20 that was pushed through. Webs as shown in FIGS. 12-15 can be made by processing through grips 116 of rolls 102 and 104 heated to about 93 ° C (200 ° F). In general, the line speed and sufficient heating of the device 100 depends on the size of the teeth 110, the winding angle of either roll, and / or the type and basis weight of the precursor web 20, all of which are relevant. It may be changed as necessary by means well known in the technical field.

As shown in the cross section of FIG. 12, the hole 6 allows the first side surface 12 and the second side surface 14 of the web 1 forming the hole through the volcanic structure 8 to fluidly pass through. The volcanic structure 8 has a continuous side wall 9 of the deformed film with a significant orientation in the Z direction and can be relatively rigid so that it can resist compression in the Z direction in use. The non-deformed portion of the web 1 forming the holes in FIGS. 12 and 13 can be fluid impermeable.

The number of holes 6 per unit area of the formed web 1 or the area density of the holes 6 can be varied from 1 hole 6 per square centimeter to a maximum of 60 holes 6 per square centimeter. Good. Depending on the end application, there may be at least 10 or at least 20 holes 6 per square centimeter. In general, the area density does not have to be uniform over the entire area of the perforated web 1, but the holes 6 have a predetermined shape, such as lines, strips, bands, circles, etc. It can only be present within certain areas of the perforated web 1, such as within areas with. In one embodiment, if the perforated web 1 is used, for example, as a topsheet for a sanitary napkin, the perforations 6 may be present only in the area corresponding to the central part of the pad where fluid infiltration occurs.

Therefore, as can be understood in the context of the molding apparatus 100, the holes 6 of the pore-formed web 1 are made by mechanically deforming the precursor web 20, which can be described as generally flat and two-dimensional. .. "Flat" and "two-dimensional" means that the web is flat compared to the web 1, which forms a hole with three-dimensionality in the Z direction that is clearly out of plane given by the formation of the volcanic structure 8. It simply means that there is. "Plane" and "two-dimensional" do not imply any particular flatness, smoothness, or dimensionality. Thus, the soft fibrous non-woven web can be flat in its as-made condition. As the precursor web 20 passes through the grip 116, the teeth 110 of the roll 104 enter the groove 108 of the roll 102 and at the same time push the material out of the plane of the precursor web 20 to create a permanent volcanic structure 8 and a hole. Form 6. In essence, the tooth 110 "pushes" or "punctures" the precursor web 20. When the tip of the tooth 110 pushes through the precursor web 20, the web material can be pushed out of the plane of the precursor web 20 by the tooth 110 and can be stretched and / or plastically deformed in the Z direction, resulting in It results in the formation of permanent volcanic structures 8 and holes 6. The ductility of the precursor web and other material properties such as glass transition temperature and crystallinity determine how well the pore-formed web 1 retains a relatively permanent three-dimensional deformation.

FIGS. 13 and 14 show another embodiment of web 1 with three-dimensional pores, where the precursor web 20 is not a flat film but a film pre-smoothed by microsteps 2. There is. The step 2 can be a protrusion, emboss, a hole, or the like. In the illustrated embodiment, the step 2 is also a volcanic micropore formed by the hydroforming process. A suitable hydroforming process is the first phase of the polyphase hydroforming process disclosed in US Pat. No. 4,609,518 issued to Curro et al. On September 2, 1986. The web-based hydroforming screen shown in Figures 14 and 15 is a "100 mesh" screen, which was obtained from Tredegar Film Products (Terre Haute, Indiana). The holes 6 were formed by the teeth 110 of the roll 104 in device 100.

As shown in the cross section of FIG. 14, in one embodiment, the holes 6 formed by the teeth 110 of the roll 104 extend away from the first side surface 12, while the micros formed by hydroforming. The hole-like step 2 extends away from the second side surface 14. Also, the step 2 can be a non-perforated protrusion, fine fibers, or embossing that provides a texture that provides a soft feel. Flexibility is beneficial when Web 1 is used as a topsheet in disposable absorbent articles, and the methods disclosed herein for forming volcanic structures 8 and holes 6 are particularly fire. When the chevron structure 8 and the hole 6 are made in the production line of disposable absorbent goods, it is effective in preserving the step 2 of the fine texture. In this way, a flexible and adaptable topsheet for disposable absorbent articles is realized when the web 1 having a hole in which the second side surface 14 has a step 2 is used as the surface of the article facing the body. be able to.

The holes 6 of the film embodiments shown in FIGS. 11-14 are made on an apparatus as shown in FIG. 2, where in FIG. 2, the apparatus 100 is a single patterned roll, eg, a roll. Arranged to have 104, and one unpatterned grooved roll 102. However, in certain embodiments, it is also preferred to form the grip 116 by using two patterned rolls with the same or different patterns in the same or different corresponding areas of each roll. is there. Such a device, along with holes 6 protruding from both sides of the perforated web 1, a web with macro textures, such as steps, micropores, or micropatterns embossed within the perforated web 1. Can be made. Similarly, it may be desirable to have multiple devices 100 to rework the web 1 with holes formed to have additional structures 8 and / or holes 6. For example, a higher areal density of the volcanic structure 8 on the perforated web 1 can be achieved by processing the precursor web 20 through two or more devices 100.

It is also conceivable that the size, shape, orientation, and spacing of the teeth 110 may be varied along the periphery and width of the roll 104 to alter the properties and characteristics of the perforated web 1. The number, spacing, and size of the holes 6 are varied by varying the shape, number, spacing, and size of the teeth 110 and, if necessary, making dimensional changes corresponding to rolls 104 and / or rolls 102. be able to. This change formed many different holes for many purposes, along with possible changes in the precursor web 20 and changes in the machining process, such as line speed, roll temperature, and other post-working changes. Allows you to create web 1.

The size of the holes produced by the process described herein is related to the size and shape of the corresponding tooth 110 as well as other previously mentioned process parameters, but the actual shape of the hole is the precursor web 20. It was found to be related to the orientation of the teeth 110 on the roll 104 relative to the molecular orientation of the long chain molecules forming. In other words, the aspect ratio of teeth placed at an angle to the molecular orientation of the film is relatively smaller than the aspect ratio of the elongated holes formed by the teeth aligned parallel to the molecular orientation of the film. It was found to form an elliptical hole with (L / W). In fact, teeth aligned perpendicular to the molecular orientation of the film form elliptical holes with an aspect ratio (L / W) close to 1.0, and teeth aligned parallel to the molecular orientation of the film It has been found that pores with an aspect ratio greater than 5.0 can be formed.

Although not bound by theory, when a tooth punctures a film web, it cuts or breaks long-chain molecules, causing them to separate. When the tooth is heated, stress relaxation or melting can occur, causing the contraction of long-chain molecules while returning it to the equilibrium point. As a result, MD-oriented teeth affect fewer long-chain molecules and result in slits when piercing the MD-oriented film, and CD-oriented teeth have more long chains in the MD-oriented film. Since it affects the molecule, it is thought to result in larger and rounder pores. Therefore, the formation of oval holes with the minimum aspect ratio is such that the relative angle between the tooth orientation and the molecular orientation of the film exceeds 0 °, preferably the relative angle between the tooth orientation and the molecular orientation of the film. It has been found that this can be achieved by altering the orientation of the teeth and / or the molecular orientation of the film so that it ranges from about 30 ° to about 90 °. More preferably, the relative angle is about 90 °.

For example, the teeth 110 on the roll 104 of the molding apparatus 100 shown in FIG. 2 are oriented so that the cross-sectional length TL of the teeth is aligned with the MD. Such MD-aligned teeth can create slits or elongated holes in the film that have a molecular orientation predominantly in MD. In comparison, in the case of the tooth 110, which is oriented so that the cross-sectional length TL of the tooth is aligned with the CD, the tooth will produce elliptical holes in the film with a molecular orientation predominant in MD. Therefore, tooth orientation on the roll can be configured to create holes in an MD oriented film with a minimum aspect ratio, preferably less than about 4.0 aspect ratio.

<p> (Example 1) The sample was prepared by passing a 100-mesh film with micropores through a molding device with a pitch of 0.13 cm (0.050 inch). In Sample 1, the teeth were oriented to MD. In Sample 2, the teeth were oriented to CD. Both films were processed at a temperature of 75 ° C. and a line speed of 15 m / min (50 ft / min). Figure 15a of Sample 1 shows the pores created by the teeth oriented in MD, and Figure 15b of Sample 2 was provided by the teeth oriented in CD. As shown, the hole length remains the same, but the width increases, which reduces the aspect ratio.</p><p><tables num="1"><img file="JP2012517536A_D0001.tif" /></tables></p><p> (Example 2) Holes were formed in the sample by orienting the film sample with respect to the teeth so that the effect of tooth orientation on the molecular orientation of the film could be assessed. A 0.13 cm (0.050 inch) pitch meshing plate was used on the high speed research press described in US Pat. Nos. 7,024,939 and 7,062,983 to form holes in a 100 mesh film sample. The sample was cut into rectangular test pieces (50 mm x 200 mm). Five different samples were prepared and cut at different angles with respect to the mechanical orientation of the film. In sample 3, the sample is cut in line with the mechanical orientation of the film, so it is designated as having an orientation angle of 0 °. Sample 7 is cut with the length dimension of the sample aligned with the transverse direction of the film, thus it is designated as having an orientation angle of 90 °. Other samples were cut at 30 °, 45 °, and 60 ° with respect to the mechanical orientation of the film. In the test, the length dimension of the sample was aligned with the cross-sectional length dimension of the teeth on the meshing plate. In this way, the effect on pore quality was determined by varying the angle between the cross-sectional length dimension of the tooth and the predominant molecular orientation (MD) of the film. The temperature of both tool plates was set to 100 ° C, and the conditions were set to a roll diameter of 205.84 mm, a web speed of 7.0 m / s (stay time 69 msec), and an engagement depth of 2.39 mm. The length and width of the 10 holes were measured and averaged to calculate the aspect ratio. The results shown in the table below show that the aspect ratio of the sample in which the holes were formed by the teeth oriented at an angle to the mechanical direction of the film was such that the teeth and the mechanical direction of the film were aligned in the same direction. It has been demonstrated to have a low aspect ratio. FIGS. 16a to 16e are photomicrographs of the holes formed in the samples 3 to 7, respectively.</p><p><tables num="2"><img file="JP2012517536A_D0002.tif" /></tables></p><p> Alternatively, the molecular orientation may be modified by plastically deforming the film before pores are formed in the film to optimize the relative angle between the tooth orientation and the molecular orientation of the film. For example, the molecular orientation of an MD-oriented film can be changed to CD by plastically deforming the web, resulting in a higher proportion of long chain molecules arranged on the CD. Preferably, the MD-oriented film can be plastically deformed so that the dominant molecular orientation is changed from MD to CD. The modified web can then pass through the grip formed by the MD-oriented teeth that result in an elliptical hole with a reduced aspect ratio.</p><p> To correct the molecular orientation of the precursor web, the web is stretched or prestrained to plastically deform the web before passing through the molding apparatus 100 shown in FIG. In one embodiment, the web can be plastically deformed by incremental stretching to stretch the precursor web. As used herein, the term "gradual stretching" is also referred to as ring rolling, in which the web is supported at tightly spaced positions and then the web is supported between these tightly separated positions. It is a process in which the unsettled section is extended. This can be achieved by passing the web through a grip formed between a pair of meshing corrugated rolls having axes of rotation perpendicular to the direction of movement of the web. Increasing stretch rolls designed for mechanical and transverse stretching are described in US Pat. No. 4,223,059.</p><p> FIG. 17 shows the interlocking of the teeth 252 and the grooves 254 of the respective opposing drive rolls in the grips that progressively extend the web 234 of the material between the teeth 252 and the grooves 254 of the respective opposing drive rolls. It is an enlarged fragmentary cross-sectional view showing the combination. As shown, a portion of the web 234, which may be a non-woven web, is accepted between the interengaging teeth and grooves. Due to the mutual engagement of the teeth and the grooves, laterally spaced portions of the web 234 are pushed into the opposing grooves 254 by the teeth 252. While passing between the drive rolls, the force of the teeth 252 pushing the web 234 into the opposing grooves 254 acts mechanically or laterally depending on the orientation of the teeth and grooves on the rolls. Tensile stress is applied within the web 234. Tensile stresses can stretch or stretch the intermediate web area 258, which exists between the tips of adjacent teeth 252 and across the space between them, in the mechanical or lateral direction, which is the intermediate web area 258. In each of these, the result can be obtained as a local reduction in web thickness. For non-woven webs, stretching can cause fiber reorientation, loss of basis weight, and controlled fiber breakdown within the intermediate web area 258.</p><p> The portion of the web 234 that exists between adjacent teeth is locally stretched, but the portion of the web that is in contact with the tip of the tooth may not undergo the same degree of expansion. Due to the frictional force present between the surface of the round outer end of the tooth 252 and the adjacent area 260 of the web 234 in contact with the tooth surface at the outer end of the tooth, on the tooth surface of the outer end of the tooth. The sliding motion of these parts of the relative web surface is minimal. As a result, in some cases, the properties of the web 234 in the area of the web in contact with the surface of the tooth tip change only slightly compared to the changes in the web properties that occur in the intermediate web area 258.</p><p> Some materials, including polypropylene, polyethylene, and polyester, cannot withstand the high-speed strain associated with gradual stretching in commercial production. Such materials can be incrementally stretched at low speed strains according to the process equipment described in US Patent Publication No. 2008/0224351 A1. The published patents provide methods and devices that use drive members to incrementally stretch the web at relatively low strain rates. The drive member includes a drive belt and a single drive member, with multiple teeth and grooves in which the drive belt and the single drive member complement and engage with each other at a certain engagement depth in the deformation zone. Including. The engagement depth can be increased linearly over the deformation zone. In a typical embodiment, the deformation zone is at least a portion of the deformation zone so that the web inserted between the drive belt and a single drive member is progressively stretched at a low strain rate within the deformation zone. It can be controlled to increase linearly over.</p><p> Another type of stretching device useful in the present invention is the tenter. Tenters have been used for lateral stretching in the film stretching process. The tenter device has a grip or clipper that grips the film along the opposite edges of the film. Stretching is caused by the opening of the opposite edge grip or clipper with respect to longitudinal movement. Such devices are described in US Pat. No. 3,816,584.</p><p> Other methods for plastically deforming the web include hydroforming and vacuum forming.</p><p> After stretching, the web continues mechanically towards the grip 116 with the pair of counter-rotating meshing rolls 102 and 104. The pair of meshing rolls 102 and 104 act to form holes in the web 1. The meshing rolls 102 and 104 are shown in more detail with reference to FIG.</p><p> (Example 3) Film samples are shrink tested according to the method of ASTM D2732-03. A square sample (each piece 10 cm (4 inches)) was cut from a 100 mesh film, impregnated with 100 ° C glycerol for 30 seconds, then removed and resized. Five samples were tested for each material and the results were averaged. Without pre-strain, the 100-mesh film sample exhibited mechanical shrinkage, but not in the transverse direction, indicating that the material had a predominant mechanical orientation. The film was prestrained by incrementally stretching the web in the transverse direction. After incremental stretching, the 100 mesh sample exhibited additional transverse contraction, indicating that molecular orientation was also introduced in the transverse direction. The data in Table 1 demonstrate that the magnitude of contraction (and thus molecular orientation) of the transverse method increases with the engagement depth adopted during ring rolling.</p><p><tables num="3"><img file="JP2012517536A_D0003.tif" /></tables></p><p> (Example 4) To illustrate the effect of web pre-strain on the holes, a 100-mesh film was ring-rolled prior to drilling. A 0.13 cm (0.050 inch) pitch meshing roll was used online at a speed of 396 m / min (1300 ft / min) to form holes in 100 mesh film. The data shown below illustrates that ring-rolling the film before drilling results in a decrease in the aspect ratio of the holes, an increase in the size of the holes, and an increase in the air permeability of the film. Figures 18a-18d are photomicrographs of the pores formed in Samples 8-11, respectively.</p><p><tables num="4"><img file="JP2012517536A_D0004.tif" /></tables></p><p> (Example 5) Holes were formed in the flat film with and without pre-straining on the film. A 0.13 cm (0.050 inch) pitch meshing plate was used on a high speed research press to form holes in a flat film sample (TS3 Flat film obtained from Tredegar Film Products in Terre Haute, Indiana). The pore forming plate temperature was set to 100 ° C and the coupling ring roll plate temperature was set to 22 ° C. The process conditions were set to a web speed of 3.125 m / s with an engagement depth of 2.6 mm. The resulting film (Sample 12) had holes with an aspect ratio of 20, which looked like slits and were slightly open. Another sample of the same film was manually stretched 50% in the transverse direction before drilling under the same conditions on a high speed research press. The resulting film (Sample 13) had perforated pores with an aspect ratio of 3.4. Figures 19a and 19b are photomicrographs of the pores formed in Samples 12 and 13, respectively.</p><p><tables num="5"><img file="JP2012517536A_D0005.tif" /></tables></p><p> Pre-strained zones to form webs with strained and unstrained regions and then holes in the precursor web, different in strained and unstrained regions It can provide a pore size. The strained and unstrained regions can be continuous or discontinuous and can be done for both MD and CD.</p><p> (Example 6) Prior to perforation, a 100 mesh film was incrementally stretched in the zones to form perforated zones, each zone having a different pore size. A sample of 100 mesh film was passed through a ring roll with a pitch of 0.10 cm (0.040 inch) and a width of 7.6 cm (3 inch) so that only the central part was acted upon. The engagement depth of the ring roll was 0.11 cm (0.045 inch). A molding device with a pitch of 0.13 cm (0.050 inch) was then used at an engagement depth of 0.11 cm (0.045 inch) and a line speed of 396 m / min (1300 ft / min) to form holes in the film. The temperature of the toothed roll was 94 ° C and the temperature of the binding roll was 99 ° C. The resulting pore-forming film had a median strip with large pores and a lateral strip with smaller pores.</p><p> Laminate The perforated web 1 is disclosed in an exemplary embodiment as a monolayer web made from a monolayer precursor web 20, but is not necessarily the case. For example, precursor web 20 which is a laminate or complex having two or more layers or plies may be used. In general, the above description of the perforated web 1 includes the recognition that the web 1 formed from a laminated precursor whose side wall 9 contains one or more precursor web materials can be composed of a volcanic structure 8. For example, if one of the materials of the composite precursor web has very low extensibility, the teeth 110 can be punctured generally cleanly and therefore do not contribute to the side wall 9 of the volcanic structure. Thus, a 3D web made from a complex or laminate precursor web 20 can include a volcanic side wall 9 in the hole 6 containing less material than all precursor web materials.</p><p> 20A-20C show a schematic diagram of the various configurations of the two-layer complex web 1 having the first surface 12 and the second surface 14, with the volcanic structure 8 extending from the second surface 12. ing. In general, each of the two precursor webs designated as 20A and 20B can be either a polymeric film or a non-woven web and is processed together in a layered relationship by a device 150 or 200 as described above. Will be done. Depending on their respective properties, such as ductility and ductility, one of the precursor webs 20A or 20B can extend to form a three-dimensional volcanic structure 8 as shown in FIGS. 19A and 19C. Can result. The other of the precursor webs 20A or 20B can simply be punctured to form a two-dimensional hole and thus virtually no three-dimensional structure. However, as shown in FIG. 19B, both the precursor webs 20A or 20B may extend out of plane to form a three-dimensional volcanic structure 8.</p><p> A multi-layered pore-formed web 1 made from a composite laminate precursor web 20 can have significant advantages over a single-layer pore-formed web 1. For example, the holes 6 from the multi-layered pores using the two precursor webs 20A and 20B are fibers in a "nested" relationship that "locks" the two precursor webs together (nonwoven web). (In the case of) or stretched film (in the case of film web) can be included. One advantage of this locking configuration is that nesting allows the formation of laminated webs with or without the need for inter-layer adhesives or additional thermal bonding, but adhesion. Agents or thermal bonds may be present. In other embodiments, the multilayer web can be selected so that the fibers of the non-woven web layer have greater extensibility than the adjacent film layer. In such a web, the pores 6 can be created by pushing the fibers out of the non-woven fabric layer and passing them through the upper film layer with little or no material contributing to the side walls 9 of the volcanic structure 8.</p><p> In a multi-layered pored web 1, each precursor web can have different material properties, thereby providing beneficial properties to the pored web 1. For example, a perforated web 1 with two (or more) precursor webs (eg, first and second precursor webs 20A and 20B) is useful for use as a topsheet for disposable absorbent articles. Can have various fluid handling characteristics. For good fluid handling in disposable absorbent articles, for example, the second precursor web 20B is an upper film layer (ie, the surface that comes into contact with the body when used as a topsheet for disposable absorbent articles). Can be formed and can be composed of a relatively hydrophobic polymer. The first precursor web 20A can be a non-woven fibrous web, a lower layer composed of relatively hydrophilic fibers (ie, topsheet and absorbent core when used in disposable absorbent articles). (Placed between and) can be formed. The fluid deposited on the upper, relatively hydrophobic layer can be quickly delivered to the lower, relatively hydrophilic layer. Depending on the use of the disposable absorbent article, the relative hydrophobicity of those layers may be reversed or modified in other ways. In general, in order to optimize the fluid handling properties of the perforated web 1, the material properties of the various layers of the perforated web 1 can be modified or modified by means known in the art. is there.</p><p> The distinct benefit of the device 150 or 200 as described above for forming a perforated web for use in disposable absorbent articles is that in the existing process for making such articles, the device 150 or It is the ability to adapt and position 200 as a unit operation. For example, the perforated web 1 may be a topsheet of an absorbent article such as a sanitary napkin. Perhaps by installing the molding equipment 150 along with the supply of topsheet material on the production line for making sanitary napkins, rather than making a web with holes formed offline at a geographically remote location. The formed web 1 can be produced online. Doing so brings some distinct advantages. First, having a molding device 150 that drills holes in the topsheet directly on the sanitary napkin production line can be costly if made by conventional processes such as vacuum forming or hydroforming. Eliminate the need to purchase a perforated web. Second, the formation of holes on the sanitary napkin production line minimizes the amount of compression and flattening that the three-dimensional volcanic region is exposed to. For example, when a molded film web with three-dimensional holes is produced and shipped in rolls, a significant amount of compression and compression set of the holes in the molded film occurs. Such compression adversely affects the behavior of the web as a fluid permeable topsheet. Third, by configuring the toothed roll 104 so that the toothed region is produced in a predetermined pattern, the perforated portion of the perforated topsheet can be formed in a predetermined pattern. For example, topsheets can be made online if the holes are located only in the middle of the sanitary napkin. Similarly, the perforated region can be perforated so that it is aligned with other visible components, including channels, markings, color signals, and the like.</p><p> The dimensions and values disclosed herein should not be understood as being strictly limited to the exact numbers listed. Rather, unless otherwise specified, each of these dimensions is intended to mean both the listed values and the functionally equivalent range around those values. For example, the dimensions disclosed as "40 mm" are intended to mean "about 40 mm".</p><p> Unless expressly excluded or limited, all documents cited herein, including any patents or patent applications that are cross-referenced or related, are all contained by reference. Incorporated into the specification. Citation of any document is that it is prior art to the invention disclosed or claimed in the present application, or that it is any such invention alone or in combination with any other reference. Is not permitted to teach, imply, or disclose. Furthermore, as long as the meaning or definition of a term in this document conflicts with the meaning or definition of the same term in the document incorporated by reference, the meaning or definition given to that term in this document shall prevail.</p><p> Although certain embodiments of the invention have been exemplified and described, it will be apparent to those skilled in the art that various other modifications and modifications can be made without departing from the spirit and scope of the invention. Therefore, all such changes and modifications within the scope of the present invention shall be treated in the appended claims.</p>