WO2009111303A1

WO2009111303A1 - Method for making an elastic laminate

Info

Publication number: WO2009111303A1
Application number: PCT/US2009/035456
Authority: WO
Inventors: Robert Ceusters
Original assignee: Avery Dennison Corporation
Priority date: 2008-02-29
Filing date: 2009-02-27
Publication date: 2009-09-11

Abstract

A method of activating a stretchable and/or scored laminate is described. The method utilizes, a rupture-inducing device (200) that comprises a wheel assembly (202) and an anvil assembly (204). The wheel assembly (202) comprises a shaft (210) and a plurality of wheels (212, 312) mounted for rotation therewith. The wheels (212, 312) are each dedicated for a corresponding area or region of the laminate or web to be activated. The anvil assembly (204) comprises a spindle (216) and a spool (218), one for each wheel (212, 312) mounted thereon. The spool (218) forms a wheel-receiving channel (220) and edge- restraining platforms (222).

Description

METHOD FOR MAKING AN ELASTIC LAMINATE

RELATED APPLICATIONS

[0001] This application claims priority upon US provisional application serial number 61/032,647 filed February 29, 2008. The entire disclosure of that provisional application is hereby incorporated by reference.

FIELD

[0002] Various methods for producing multilayer laminates are described. In particular, a method is disclosed for making an elastic laminate comprising an elastic layer and at least one fabric layer, e.g., a nonwoven layer, laminated thereto. Also disclosed is a rupture- inducing device used in the noted method.

BACKGROUND

[0003] An elastic laminate can be used in a variety of situations where elasticity is required or desired for one reason or another. For example, in the field of disposable absorbent articles, e.g., diapers, incontinence briefs, etc., an elastic laminate can be used as, or incorporated into, a side panel or a belt for attachment to a rear chassis portion. A fastening tape, for attaching a rear chassis portion to a front chassis portion, can also comprise a stretchable laminate. A stretchable laminate can be used to form the diaper/brief chassis itself, or portions/regions thereof, e.g., waist regions in a front or rear chassis portion, leg-opening regions in a crotch portion, etc. With these and other applications, it is often necessary or desirable to use a fabric layer, e.g., a nonwoven fabric layer, as the skin contact layer and/or the exposed layer.

[0004] Numerous methods and practices are known in the art for manufacturing stretchable laminates and elastic laminates. Although many of these methods are satisfactory, a need remains for an improved method, and in particular, a method that can be performed cost effectively in a high volume manufacturing environment.

SUMMARY

[0005] In one aspect, the present invention provides a method of activating a stretchable laminate. The method comprises a step of passing a scored laminate through a rupture- inducing device that integratively stretches an activation area of the laminate. [0006] In another aspect, the present invention provides a rupture-inducing device adapted for integratively stretching at least a portion of a stretchable laminate as described herein. The device comprises a wheel assembly and an anvil assembly, which preferably engage one another in a unique configuration such that a web or material laminate is selectively restrained and activated.

DRAWINGS

[0007] Figure 1 schematically illustrates a preferred embodiment method in accordance with the present invention, of activating a laminate web to form an elastic laminate. [0008] Figure 2 schematically shows an elastic laminate resulting from the elastic web of Figure 1.

[0009] Figure 3 schematically diagrams initial scores and ruptures induced by a preferred embodiment device in accordance with the present invention, and fabric segments resulting therefrom.

[0010] Figure 4 schematically depicts a portion of the preferred embodiment rupture- inducing device.

[0011] Figures 5A and 5B schematically illustrate various activation patterns of a web resulting from different rim geometries of a wheel used in the preferred embodiment rupture- inducing device.

[0012] Figures 6A and 6B each schematically depict a wheel with a certain preferred wheel rim geometry in accordance with the present invention.

[0013] Figures 7A, 7B, and 7C schematically illustrate a preferred embodiment wheel for use in the wheel assembly and rupture-inducing device.

DESCRIPTION

[0014] The present invention provides various methods for forming elastic laminates comprising one or more elastic layer(s) and at least one fabric layer that is laminated to the elastic layer(s). The present invention also provides various devices for use in these methods. In particular, a preferred device is a rupture-inducing device that utilizes (i) a particular wheel assembly having a certain geometrical configuration and (ii) a particular anvil assembly. The preferred rupture-inducing device can be used to activate all or a portion of a laminate web to form an elastic laminate. These and other aspects of the present invention are described in greater detail herein.

[0015] In accordance with the present invention, an elastic laminate can be produced by a method wherein a scored laminate is passed through a rupture-inducing device. The rupture-inducing device preferably comprises a single wheel for each activation area in the laminate. The collection of wheel(s) and associated drive shaft(s) are referred to herein as a wheel assembly. The device's wheel assembly, in concert with its anvil assembly, accomplishes activation by integrative stretching. The equipment that performs this integrative activation, is easier to manufacture, assemble, inspect, and/or maintain as compared to, for example, incremental stretching equipment. The use of integrative stretching equipment in turn, enables a more cost effective process to be implemented. [0016] Figure 1 schematically illustrates a preferred method of activating a laminate web 108 to form an elastic laminate (or elastic laminate web) 1 10. The method uses a rupture- inducing device 200. The device 200 preferably includes a wheel assembly 202 and an anvil assembly 204.

[0017] Figure 2 schematically illustrates an elastic laminate 10 cut from the previously noted elastic laminate web 110. The elastic laminate 10 comprises an elastic layer 20, a first fabric layer 30, a second fabric layer 40, and adhesive layers 53/54. The first fabric layer 30 includes an activation area with scores 31 and ruptures 32, and the second fabric layer 40 includes an activation area with scores 41 and ruptures 42.

[0018] Figure 3 schematically diagrams the initial scores 31/41 , the ruptures 32/42 induced by the device 200, and resulting fabric segments 33/43 that diverge upon laminate elongation. All of these various aspects and details are described in greater detail as follows. Before describing the preferred embodiment rupture-inducing device, various aspects of the laminates 108/110 are detailed as follows.

Fabric Layers 30/40

[0019] As noted, the laminates 108/110 comprise one or more fabric layers. Referring to the accompanying figures, the fabric layers 30/40 can be nonwoven layers. The fabric layers can comprise, for example, polyolefins, such as polyethylene and/or its copolymers, or polypropylene and/or its copolymers, or mixtures of the aforementioned polyolefins, polyurethanes, polyester, polyether or polyamide. The nonwoven materials can comprise, for example, spunbonded webs, meltblown webs, air-laid layer webs, bonded carded webs, hydroentangled webs, wet-formed webs or any combination thereof. The nonwoven layers can have a weight of from about 10 gsm to about 100 gsmi and the layers 30/40 can vary in weight.

[0020] The layers 30/40 can be fabric monolayers that are a single layer of fabric rather than a laminate of a plurality of sublayers. For example, a monolayer structure wherein fibers or other filaments are fused or otherwise integrated into a single substrate layer can be employed. While monolayer constructions will be preferred in many situations, the layers 30/40 could alternatively have a multilayer construction, i.e., a compilation or lamination of layers wherein different layers are distinguishable and/or separable.

[0021] The fabric layers 30/40 can be inherently elastic fabric layers. A fabric is inherently elastic when it comprises mostly elastic fibers. Elastic fabric layers 30/40, e.g., elastic nonwoven layers can be significantly more expensive than inelastic fabric layers. But they can accommodate the elongation recovery of the elastic layer 20 without further manipulation, modification, or alteration. In the laminate-making method described in detail herein, the fabric layers 30/40 can be dispensed from rolls or other formats capable of continuous supply for immediate lamination to the intermediate elastic layer 20 without intermediate steps or equipment.

[0022] The fabric layers 30/40 can be elasticized fabric layers. The fabric layer 30 and/or the fabric layer 40 can each be made from an inelastic fabric, e.g., inelastic nonwoven fabric, that is manipulated to behave elastically by elasticizing steps. Preferably, the elasticizing steps include the preferred embodiment method utilizing the previously described rupture- inducing device. In addition or alternatively, the elasticizing steps can comprise heating the inelastic fabric in an oven and simultaneously drawing it in the machine direction (MD). This heating-drawing reorients most of the fabric's inelastic fibers in the MD. The elasticizing steps can be performed inline with film-formation steps and/or fabric-lamination steps. But off-line performance and providing the fabric layers in a format suitable for continuous supply may be best. In some cases, the cost and/or the inconvenience of elasticizing steps may be well worth the money saved by not using elastic fabrics. Additionally, elasticized fabrics are often better at insuring uniaxial elasticity, i.e., elastic behavior in the cross direction (CD) but not the machine direction (MD), than inherently elastic fabrics.

[0023] The fabric layer 30 and/or the fabric layer 40 can each be made from an inelastic fabric, e.g., an inelastic nonwoven fabric. In some cases, the fabric layer 30/40 will be inherently extendable although not elastic.

[0024] The fabric layer 30/40 can be permanently elongated to extend-contract in a pleat- like fashion during laminate elongation-recovery. Such permanent elongation can be accomplished by incremental stretching, e.g., ring-rolling, or region-specific stretching, and/or integrative stretching as described herein. Alternatively, an elastic layer 20 can be attached to fabric layer 30/40 in an elongated state. In either case, the effected fabric regions will usually take on a wavy, creased, or wrinkled geometry when the laminate 10, 110 is in a relaxed or recovered condition.

[0025] The fabric layer 30/40 can be provided with interruptions that extend only partially through the fabric thickness, e.g., 20%, 40%, 80%, 90%, etc., to provide the fabric with enough "give" to extend during laminate elongation. The partial interruptions can be in the form of scores, in the form of ruptures, or any other suitable form. The scored portions are formed by severing, e.g., cutting, slitting, scoring, etc., by means of a tool, e.g., rotary or stationary knife or blade, applying a force in the normal direction (ND) and are defined primarily by cleanly severed fibers. The ruptured portions are formed by rupturing, e.g., breaking, tearing, ripping, fracturing, etc., by applying a tension in the cross direction (CD) and are defined primarily by uneven and ruptured fibers. Various contemplated configurations and locations for the interruptions, scored portions, ruptures, and the like are described in greater detail with regard to additional embodiments of the present invention. [0026] The fabric layer 30/40 can be provided with interruptions that extend completely through the fabric thickness. In this case, the fabric layers 30/40 can be divided into separate fabric segments that diverge upon laminate elongation and converge upon laminate recovery. The interruptions can comprise complete cuts, a scored portion and a ruptured portion, or complete ruptures. The fabric layer 30/40 can have only a single region 31/41 , multiple regions, or its entirety mechanically altered.

[0027] For embodiments utilizing adjacent interruptions, they are preferably spaced a distance between about 1 mm and about 10 mm.

[0028] The fabric layer 30 and the fabric layer 40 can be supplied in a format suitable for continuous supply, e.g., a roll. In-line production of the fabric layer 30 and/or the fabric layer 40 is possible and contemplated. The fabric layers 30 and 40 can be the same fabric, and supplied from the same stock. If supplied from the same stock, a single roll can be split, inline or off-line, to provide the fabric layers 30/40.

[0029] The first fabric layer 30 may extend across the entire laminate width in the cross direction (CD). The second fabric layer 40 may extend across the entire laminate width in the cross direction (CD). It is also contemplated that the first fabric layer 30 may not extend across the entire laminate width in the cross direction (CD). Similarly, the second fabric layer 40 may extend across the entire laminate width in the cross direction (CD). Alternatively, the second fabric layer 40 may not extend across the entire laminate width in the cross direction (CD).

[0030] As will be understood, the present invention includes the use of a wide range of materials for the fabric layers. For forming laminates using the integrative stretching technique described herein, spun bond nonwoven fabric layers having weights of from about 20 g/m² to about 60 g/m² may be acceptable for many applications.

Intermediate Elastic Layer 20

[0031] As previously noted, the laminates 108/110 comprise one or more elastic layers, preferably disposed between the fabric layers. Referring to the accompanying figures, the intermediate layer 20 is preferably elastic.

[0032] The elastic layer 20 can comprise an elastomeric polymer and optionally comprise a nonelastomeric polymer. The elastic layer can comprise block copolymers (A-B or A-B-A block copolymers), such as styrene/isoprene, butadiene or ethylene-butylene/styrene (SIS, SBS or SEBS). Other useful elastomeric materials can include elastomeric polyurethanes, ethylene copolymers such as ethylene vinyl acetates, ethylene/propylene copolymer elastomers or diene copolymer elastomers, and/or blends of these elastomers with each other or with modifying non-elastomers.

[0033] The elastic layer 20 can comprise a vinyl arene-containing block copolymer, and be substantially free of a tackifying amount of a tackifier. The elastic layer can be a mixture including SBS and/or SEBS with or without an additive including one or more of polystyrene, poly-(alpha-methyl)styrene, an ethylene-vinyl acetate copolymer, an ethylene- methyl(meth)acrylate copolymer, an ethylene-ethyl(meth)acrylate copolymer, an ethylene- (meth)acrylic acid copolymer.

[0034] The elastic layer 20 can be formed from any suitable polyvinyl arene) and poly( conjugated diene) or poly(olefinic), for example, elastomeric (polystyrene/poly(ethylene- butylene)/polystyrene) (SEBS) block copolymers and/or

(polystyrene/poly(butadiene)/polystyrene) (SBS) block copolymers. Commercial examples of such elastomeric copolymers are, for example, those known as KRATON^® materials, such as, for example KRATON® G-1657, which are available from KRATON Polymers of Houston, Texas. KRATON® block copolymers are available in a variety of different formula numbers and grades. A compounded composition containing a suitable elastomeric copolymer is DRYFLEX^® 938115, available from VTC Elastoteknik AB of Amal, Sweden. DRYFLEX® 938115 is a proprietary blend of SEBS and other polymers.

Adhesive Sublayers 53, 54

[0035] Referring further to the accompanying figures, the stretchable laminate 108, elastic laminate 1 10, and/or the elastic laminate 10 resulting therefrom, can include one or more of an adhesive sublayer 53 and an adhesive sublayer 54.

[0036] The adhesive sublayer 53 is situated between the first fabric layer 30 and the elastic layer 20. The adhesive sublayer 53 can extend completely or only partially across the laminate's width in the cross direction (CD).

[0037] The adhesive sublayer 54 is situated between the second fabric layer 40 and the elastic layer 20. The adhesive sublayer 54 can extend completely or only partially across the laminate's width in the cross direction (CD).

[0038] The adhesive sublayers 53/54 can comprise hot-melt adhesives, e.g., hot-melt rubber-based materials or acrylic-based materials, and/or non-hot-melt adhesives, such as pressure sensitive adhesives, polyurethane adhesives and structural adhesives. The adhesive can be solid or continuous in the bonding area, or it can be applied in intermittent adhesive patterns, e.g., stripes, spots, swirls, islands, grids, checkerboard, voids, random, semi-random, etc.

[0039] Although the present invention includes the use of a wide range of adhesives and in varying amounts, for certain applications and for forming many of the laminates described herein using an integrative stretching technique, adhesive application weights of typically less than 15 g/m² are suitable with about 10 g/m² being preferred. Excessive amounts of adhesive may lead to uneven activation.

Rupture-Inducing Device

[0040] Figure 4 schematically illustrates a portion of the preferred embodiment rupture- inducing device 200. The device 200 includes a wheel assembly 202 and an anvil assembly 204. The wheel assembly 202 comprises a rotatable shaft 210 and a plurality of wheels 212 mounted for rotation therewith. The wheel assembly 202 can include a common shaft 210, and a wheel 212 for each activation area of the web 108. Six areas are included in the illustrated embodiment in Figure 1. It will be understood that the present invention includes the use of a greater or lesser number of wheels. Each wheel 212 preferably includes an outwardly extending rim 214 that contacts a central portion of the corresponding activation area of the web when urged against the web. The anvil assembly 204 includes a spindle 216 and a series of spools 218, preferably one for each wheel 212, mounted thereon. Each spool 218 forms a wheel-receiving recess 220 and platforms 222 for restraining edges of the activation area. As an activation area of the web moves through the rupture-inducing device 200, and specifically, between the wheel assembly 202 and the anvil assembly 204, the wheel 212 stretches the web material out of the web's plane and into the recess 220. The two edge portions of the material are restrained between the wheel assembly 202 and the platforms 222 and the material's central section is preferably restrained between the wheel's rim 214 and the floor of the recess 220. Thus, there are preferably three restraint points provided by the device 200, with the material therebetween being stretched. [0041] Figures 5A and 5B schematically illustrate how Ihe geometry of the wheel's rim 214 can effect activation patterns. In Figure 5A, the rim 214 is relatively wide whereby a large central portion of the material is restrained, rather than stretched. In Figure 5B, a thinner rim 214 is used whereby less of the central material is restrained and more is stretched. It will be appreciated that the present invention includes any combination of these central portion and rim proportions.

[0042] Figures 6A and 6B each schematically depict cross sections of a wheel 210 with a preferred embodiment wheel rim geometry. The wheel rim 214 of the wheel 212 shown in Figure 6A can be used to produce the activation pattern shown in Figure 5A. And, the wheel rim 214 of the wheel 212 shown in Figure 6B can used to produce the activation pattern shown in Figure 5B.

[0043] Referring to Figure 4 again, the wheel assembly 202 generally comprises a shaft 210 and a wheel 212 mounted for rotation therewith. The wheel assembly 202 can comprise a plurality of wheels 212 mounted to the shaft 210 for rotation therewith. Typically, the wheel assembly 202 comprises a common shaft 210 to which the plurality of wheels 212 are mounted. The wheel assembly 202 preferably comprises a wheel 212 for each activation area of the laminate web 108. In a typical application, the wheel assembly 202 comprises six wheels 212. Each wheel 212 can include a rim 214 that contacts a central portion of the corresponding activation area. Preferably, the rim 214 extends radially outward from an interior portion of the wheel 212 proximate the shaft 210. The rim 214 defines a circumferential distal edge 214a and corresponding oppositely directed side faces 214b and 214c, as shown in Figure 4. The wheel 212 defines a generally circumferential outer face 212a. The rim side faces 214b and 214c extend between Ihe rim distal edge 214a and the wheel outer face 212a. For assemblies comprising one or more wheels 212 positioned along a shaft 210, the circumferential outer face of the shaft 210 may constitute the previously described wheel outer face 212a.

[0044] The rupture-inducing device 200 preferably comprises an anvil assembly 204. The anvil assembly 204 preferably comprises a spindle 216 and a spool 218 mounted thereon. The anvil assembly 204 can comprise a spool 218 for each wheel 212 on the wheel assembly 202. Each spool 218 may form a wheel-receiving recess 220. And, each spool 218 generally forms platforms 222 for restraining edges of the activation area. Preferably, the platforms 222 extend radially outward from an interior portion of the spool 218 proximate the spindle 216. Each platform 222 defines a circumferential distal edge 222a and a corresponding side face 222b as shown in Figure 4. For a pair of platforms 222 as shown in Figure 4, preferably the side faces 222b are directed toward one another. The spool 218 defines a generally circumferential outer face 218a extending between the side faces 222b of the projections 222. The region defined by the side faces 222b and the outer face 218a of the spool 218 is the noted wheel receiving recess 220.

[0045] In accordance with the present invention, various preferred relationships between aspects of the wheel assembly 202 and the anvil assembly 204 have been identified. As explained, during operation of the rupture-inducing device, the wheel(s) 212 rotate about a corresponding shaft such as shaft 210. The spool 218 rotates about the spindle 216 or an equivalent component. Preferably, the circumferential outer edges of the platforms 222, i.e. the distal edges 222a, contact, engage, or nearly so, corresponding regions along the wheel 212, i.e. regions of the outer face 212a. And, the wheel 212 defines an outwardly projecting rim 214 which is sized and configured to extend into the wheel receiving recess 220 defined by the spool 218 and specifically, between the inner side faces 222b of the platforms 222. Preferably, the rim distal edge 214a, contacts, engages, or nearly so, a corresponding region along the floor of the wheel receiving recess 220, i.e. a region of the circumferential outer face 218a of the spool 218. [0046] Although it is preferred for certain applications that the rim distal edge 214a contacts or engages the floor of the wheel receiving recess 220, the present application includes embodiments in which the wheel assembly 202 and the anvil assembly 204 are configured such that the rim distal edge 214a does not contact the circumferential outer face 218a of the spool 218. Before describing these various preferred relationships, it is instructive to define the height of the rim 214 and the depth of the recess 220. The rim height as referenced herein is the distance between the rim distal edge 214a and the wheel outer face 212a as measured along a line perpendicular to the axis of rotation of the wheel 212 and/or the shaft 210. The wheel receiving recess depth is the distance between the projection distal edge 222a and the spool outer face 218a, also as measured along a line perpendicular to the axis of rotation of the spool 218 and/or the spindle 216. [0047] Preferably, and in accordance with the embodiments of the present invention in which the rim distal edge 214a does not contact the floor of the recess 220, the rim height is at least 10% and up to about 95% of the wheel receiving recess depth. It will be understood that the greater this percentage, the greater the extent of stretching that will occur of a material when introduced to the wheel assembly 202 of a rupture-inducing device. Similarly, the less this percentage, the less the extent of stretching that will occur. [0048] The width of the rim distal edge 214a also affects the extent of stretching of a material. The width of the rim distal edge 214a is the linear distance measured along that edge, generally in a direction parallel with the axis of the wheel 212. As previously explained with regard to Figures 5A and 5B, greater stretching occurs by use of a relatively wide distal edge 214a (for rims of equal rim height).

[0049] Preferably, and in accordance with the present invention, the width of the rim distal edge is at least 10% and up to about 80% of the width of the wheel receiving recess. The width of the wheel receiving recess is generally the distance between the inner side faces 222b of the platforms 222 taken along a line generally parallel with the axis of rotation of the spool 218 and/or the spindle 216, and measured proximate the distal edges 222a of the platforms 222.

[0050] Figures 7A - 7C illustrate a preferred embodiment wheel 312 in accordance with the present invention. The preferred embodiment wheel 312 can be used in association with the wheel assembly and rupture-inducing device described herein. The wheel 312 defines oppositely directed side faces 312b and 312c, which are preferably parallel with one another. The wheel 312 also defines a circumferential rim 314 extending about its perimeter. The rim includes a distal edge 314a and side faces 314b and 314c. The wheel 312 also defines a centrally aligned bore 318 extending through the thickness of the wheel and between side faces 312b and 312c. The wheel 312 may also define one or more apertures 316 spaced about the bore 318 for receiving fasteners or other members. Preferably, the wheel 312 defines four apertures spaced equidistant from one another about the bore 318. [0051] The wheel 312 features a unique rim configuration, which is schematically depicted in Figure 7c. As previously described, the rim 314 of the wheel 312 defines a rim side face 314b and a rim side face 314c. Preferably, these rim side faces extend from the wheel side faces 312b and 312c toward the rim distal edge 314a, such that the rim side faces are oriented at particular angles with respect to one another. Thus, at a region proximate the wheel side faces 312b and 312c, the rim side faces 314b and 314c are oriented at an angle A with respect to one another. And, at a region proximate the rim distal edge 314a, the rim side faces 314b and 314c are oriented at an angle B with respect to one another. Preferably, the angles and corresponding orientations of the rim side faces 314b and 314c are selected such that angle A is greater than angle B. Furthermore, it is preferred that the regions along the rim side faces 314b and 314c at which the side faces are oriented at angles A and B gradually transition to one another, to thereby define a relatively smooth interface region.

[0052] The wheel 312 includes a wide array of geometries and rim configurations. Generally, for the integrative stretching techniques described herein, the angle A can range from about 60° to about 25°, more preferable from about 50° to about 35°, more preferably from about 45° to about 42°, and most preferably about 44°. It will be understood that the present invention includes rim configurations using A angles greater than 60°, and less than 25°. The angle B can range from about 50° to about 15°, preferably from about 40° to about 25°, more preferably from about 34° to about 31 °, and most preferably about 32.5°. [0053] The wheel 312 can be formed from a wide range of materials, such as metals, polymeric materials, various composite materials and the like. Aluminum is a representative preferred material. Various surface coatings can be applied to select outer regions of the wheel as desired. Examples of such coatings include, but are not limited to, high friction coatings, anti-stick coatings, low friction coatings, protective wear-resistant coatings, and coatings exhibiting combinations of these properties.

[0054] Thus, by appropriate selection of the rim height, wheel receiving recess depth, the width of the rim distal edge, and/or the width of the wheel receiving recess, particular regions of a web can be activated and activated to certain extents.

Methods

[0055] The present invention provides various preferred methods for selectively activating a stretchable laminate as described herein. In one embodiment, the present invention provides a method of activating a stretchable laminate 108. The method comprises a step of scoring a laminate 108 or portions thereof. The method also comprises a step of passing the scored laminate 108 through a rupture-inducing device 200 that integratively stretches an activation area of the laminate. The rupture-inducing device 200 preferably utilizes a plurality of restraining points and most preferably has three restraining points, and stretches the material therebetween. The rupture-inducing device 200 preferably comprises a wheel assembly 202 which is rotated during the activating step(s). The rotating wheel assembly 202 preferably engages a rotating anvil assembly 204.

Scoring

[0056] Preferably, a stretchable laminate 108 utilizes one or more fabric layers, such as fabric layers 30/40 that exhibit one or more scores, or scored regions or portions. [0057] The scored portions are preferably formed by severing, e.g., cutting, slitting, scoring, etc., by means of a tool, e.g., rotary or stationary knife or blade, applying a force in the normal direction (ND) and are defined primarily by cleanly severed fibers. Various contemplated configurations and locations for the scored portions and the like are included in the present invention.

[0058] Concerning the scores or scored regions, the scores may extend at least 10% through the thickness of the fabric layer 30/40. In other embodiments, the scores may extend at least 20% through the thickness of the fabric layer 30/40. In other versions, the scores may extend at least 30% through the thickness of the fabric layer 30/40. In other embodiments, the scores may extend at least 40% through the thickness of the fabric layer 30/40. In still other embodiments, the scores may extend at least 50% through the thickness of the fabric layer 30/40. And, in other embodiments, the scores may extend at least 60% through the thickness of the fabric layer 30/40. Furthermore, in other embodiments, the scores may extend at least 70% through the thickness of the fabric layer 30/40. And, in other embodiments, the scores may extend at least 80% through the thickness of the fabric layer 30/40.

[0059] The scores may have substantially the same height across the fabric layer 30/40. In other embodiments, the scores have differing heights across the fabric layer 30/40. Again, the preferred embodiments include a wide range of variations.

[0060] It is generally preferred to score at least one, and most preferably both, of the fabric layers. For elastic laminates exhibiting one or more regions of equal stretching, it is preferred to score the fabric in those regions in an equal manner, e.g. score the fabric layers in equally sized regions, symmetrically located from one another, and form scores of equal size and using an equal or equivalent scoring pattern. An example of a scored pattern is one formed in a fabric layer that defines a collection of 2 mm lines or cuts, symmetrically arranged within the pattern region. Integrative Stretching

[0061] After one or more layers or regions of the stretchable laminate 108 are scored, the laminate is integratively stretched. Preferably, this is performed by using the rupture-inducing device 200 described herein. However, the present invention includes the use of other devices and/or assemblies. The term "integrative stretching" as used herein refers to an operation in which a selected region(s) of one or more layers of a stretchable material or laminate, is selectively stretched, elongated, or otherwise expanded in one or more directions; while another region(s) is not subjected to the selective stretching operation. Preferably, the other region(s) not subjected to the selective stretching operation are retained or otherwise held between engaging faces of a device or assembly performing the selective stretching. Most preferably, the selective stretching of one or more region(s) and the retention of one or more other region(s), are performed concurrently. As previously noted, integrative stretching of the stretchable laminate 108 can be performed by the rupture- inducing device 200 described herein.

[0062] Specifically, integrative stretching is performed using the preferred embodiment rupture-inducing device 200 as follows. One or both of the wheel assembly 202 and the anvil assembly 204 are rotated. It is contemplated that a powered rotary drive may be applied to both, or to only one assembly, whereby the other assembly then passively rotates. As will be appreciated, since certain regions of the assemblies contact, engage, or substantially contact/engage one another, the rotation direction of each assembly is opposite from the other.

[0063] After the wheel and anvil assemblies are rotating at their desired operating speeds, a stretchable laminate 108, or rather a laminate web providing such, is introduced in the interface region between the two rotating assemblies. Upon contact between the laminate 108 and one or both of the wheel and anvil assemblies 202 and 204, the laminate is drawn into the device 200. Specifically, the laminate 108 is contacted by the circumferential distal edges 222a of the projections 222 of the spool 218 and corresponding regions along the circumferential outer face 212a of the wheel 212. For the device configuration depicted in Figure 4, two regions of such contact occur. These two regions of contact serve to restrain the laminate while a portion of the laminate between these two regions is subjected to a stretching, elongation, or deformation operation. This stretching operation is achieved by placement of a distal edge 214a of the rotating rim 214 against the portion of the laminate, and then application of a force at that portion in contact with the distal edge 214a as the laminate travels with the rotating rim 214 into the wheel receiving recess 220 defined by the spool 218. The region of contact between the rim distal edge 214a and the laminate is a third point of contact between the laminate and the device 200. As noted, for certain applications, it may be preferred that the rim height be such that the rim distal edge 214a contact or otherwise engage the outer face 218a of the spool 218. In these applications, the laminate is engaged and thus retained between the rim 214 and the floor of the recess 220. The collection and result of these operations is referred to herein as integrative stretching. [0064] Thus, by appropriate selection of (i) the rim height, (ii) the wheel receiving recess depth, (iii) the width of the rim distal edge 214a, and (iv) the width of the wheel receiving recess, a wide array of different stretching configurations can be achieved by use of the preferred embodiment rupture-inducing device 200. It is also recognized that different stretching and/or activation configurations can be achieved by appropriate selection of only one, two, or three of these parameters (i) - (iv). The present invention includes selection of one, two, three, or four of these parameters in combination with other parameters to selectively stretch and/or activate desired regions of a laminate.

[0065] The preferred embodiment methods described herein can be performed using equipment from a wide array of sources and suppliers. Production speeds of from 20 m/min. and more typically, 50 m/min. to 500 m/min. are contemplated with even higher speeds possible.

[0066] The various techniques described herein can produce elastic laminates having a wide range of characteristics. Depending upon the characteristics of the elastic film and the activation depth, elongations of the laminate can be achieved in the range of 0 to up to 30 mm or more. The combination of activation depth, width of the film, film composition, the scoring width, and scoring design will result in particular degrees of elongation and resulting differences in thickness of the laminate.

[0067] During integrative stretching, the extent of stretching of the laminate assembly can be expressed in terms of a percentage based upon a dimension of the laminate prior to stretching. For many applications, the extent of stretching is from 100% to 200% or more, with 150% being typical. It will be understood that the present invention includes stretching to significantly greater extents.

[0068] Although the laminate webs 108/110, the laminate 10, the rupture inducing device 200, associated components or elements, and/or corresponding methods/steps have been shown and described with respect to certain embodiments, it will be understood that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In regard to the various functions performed by the above described elements, e.g., components, assemblies, systems, devices, compositions, etc., the terms including a reference to a "means" used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element, i.e., that is functionally equivalent, even though not structurally equivalent to the disclosed structure which performs the function. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application. If incorporated-by- reference subject matter is inconsistent with subject matter expressly set forth in the written specification and drawings of this disclosure, the latter governs to the extent necessary to eliminate indefiniteness and/or clarity-lacking issues.

[0069] Many other benefits will no doubt become apparent from future application and development of this technology.

[0070] All patents, published patent applications, and articles referenced herein are incorporated by reference in their entirety.

[0071] Any and all aspects of any of the structures, products, and processes described herein can be combined with one or more aspects of any of the other structures, products, and processes described herein.

[0072] As described hereinabove, the present invention solves many problems associated with previous type laminates, garments, methods and associated systems.

However, it will be appreciated that various changes in the details, materials and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art without departing from the principle and scope of the invention, as expressed in the appended claims.

Claims

1. A method of activating a stretchable laminate, said method comprising a step of passing a scored laminate (108) through a rupture-inducing device (200) that integratively stretches an activation area of the laminate.

2. A method as set forth in claim 1 , wherein the rupture-inducing device (200) provides three restraining points and stretches the scored laminate therebetween.

3. A method as set forth in claim 1 , wherein the rupture-inducing device (200) comprises a wheel assembly (202) which is rotated during activating of the laminate.

4. A method as set forth in claim 3, wherein the wheel assembly (202) comprises a shaft (210) and a wheel (212, 312) mounted for rotation therewith.

5. A method as set forth in claim 4, wherein the wheel assembly (202) comprises a plurality of wheels (212, 312) mounted to the shaft (210) for rotation therewith.

6. A method as set forth in claim 5, wherein the wheel assembly (202) comprises a common shaft (210) to which the plurality of wheels (212, 312) are mounted.

7. A method as set forth in claim 5, wherein the wheel assembly (202) comprises a wheel (212, 312) for each activation area of the laminate web (108).

8. A method as set forth in claim 3, wherein the wheel assembly (202) comprises six wheels (212, 312).

9. A method as set forth in claim 4, wherein each wheel (212, 312) includes a rim (214) that contacts a central portion of the corresponding activation area of the laminate.

10. A method as set forth in claim 1 , wherein the rupture-inducing device (200) comprises an anvil assembly (204)

1 1. A method as set forth in claim 10, wherein the anvil assembly (204) comprises a spindle (216) and a spool (218) mounted thereon.

12. A method as set forth in claim 10, wherein the anvil assembly (204) comprises a spool (218) for each wheel (212) on the wheel assembly (202).

13. A method as set forth in claim 11 , wherein each spool (218) defines a wheel- receiving recess (220).

14. A method as set forth in claim 11 , wherein each spool (218) includes platforms (222) for restraining edges of the activation area.

15. A rupture-inducing device (200) adapted for integratively stretching a region of a stretchabie laminate (108) as set forth in the method of claim 1 , the device comprising: a wheel assembly (202); and an anvil assembly (204).

16. A rupture-inducing device (200) as set forth in claim 15 wherein the wheel assembly (202) comprises: a rotatable shaft (210); and one or more wheels (212, 312) mounted on the shaft (210) and rotatable therewith.

17. A rupture-inducing device (200) as set forth in claim 16 wherein each wheel (212, 312) includes a rim (214, 314) extending radially outward from an interior portion of the wheel (212).

18. A rupture-inducing device (200) as set forth in claim 17 wherein the anvil assembly (204) comprises a spindle (216) and a spool (218) mounted on the spindle (216), the spool (218) defining a wheel-receiving recess (220).

19. A rupture-inducing device (200) as set forth in claim 18 wherein the wheel assembly (202) and the anvil assembly (204) are positioned adjacent each other such that the rim (214, 314) of the wheel (212, 312) at least partially extends into the wheel receiving recess (220).

20. A rupture-inducing device (200) as set forth in claim 17 wherein the rim (214, 314) defines a distal edge (214a, 314a) that contacts a portion of the laminate (108) during integrative stretching.

21. A rupture-inducing device (200) as set forth in claim 16, wherein the wheel (312) defines a centrally aligned bore (318), a rim distal edge (314a), a first wheel side face (312b) and a first rim side face (314b) extending between the bore (318) and the distal edge (314a) and a second wheel side face (312c) and a second rim side face (314c) extending between the bore (318) and the distal edge (314a), wherein (i) the first rim side face (314b) and the second rim side face (314c) are oriented at an angle A from one another at a region proximate the wheel side faces (312b) and (312c), and (ii) the first rim side face (314b) and the second rim side face (314c) are oriented at an angle B from one another at a region proximate the distal edge (314a), wherein angle A is greater than angle B.

22. A rupture-inducing device (200) as set forth in claim 21 , wherein angle A is an angle in the range from 60° to 25°.

23. A rupture-inducing device (200) as set forth in claim 22, wherein angle A is an angle in the range from 50° to 35°.

24. A rupture-inducing device (200) as set forth in claim 23, wherein angle A is an angle in the range from 45° to 42°.

25. A rupture-inducing device (200) as set forth in claim 24, wherein angle A is 44°.

26. A rupture-inducing device (200) as set forth in claim 21 , wherein angle B is an angle in the range from 50° to 15°.

27. A rupture-inducing device (200) as set forth in claim 26, wherein angle B is an angle in the range from 40° to 25°.

28. A rupture-inducing device (200) as set forth in claim 27, wherein angle B is an angle in the range from 34° to 31 °.

29. A rupture-inducing device (200) as set forth in claim 28, wherein angle B is 32.5°.

30. A rupture-inducing device (200) as set forth in claim 21 , wherein angle A is an angle in the range from 45° to 42°, and angle B is an angle in the range from 34° to 31°.