DE9018126U1 - Elastic composite material that can be stretched in several directions - Google Patents

Description

Description

The present innovation concerns an elastic dressing material that can be stretched in at least two directions.

Synthetic nonwoven webs formed by nonwoven extrusion processes such as melt blowing and spunbonding can be made into products and product components at such low cost that the products can be considered disposable after only one or infrequent use. Examples of such products include diapers, wipes, garments, mattress pads and feminine hygiene products.

Problems in this area include providing an elastic material that is elastic and pliable, but still feels comfortable. One problem is providing an elastic material that does not feel plastic-like or rubbery. The properties of the elastic materials can be improved by forming a laminate of an elastic material with one or more non-elastic materials on the outer surface that provide better grip properties.

Nonwoven webs made of non-elastic polymers, such as

For example, polypropylene, are generally considered non-elastic. The lack of elasticity usually limits these nonwoven web materials to applications where elasticity is not required.

Composites of elastic and non-elastic materials were created by bonding non-elastic materials to elastic materials in this way.

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manufactured such that the entire composite material can be stretched or extended, usually in one direction, so that it can be used in clothing materials, pads, diapers and personal care products where elasticity may be desired.

In such a composite material, a non-elastic material is bonded to an elastic layer while the elastic layer is in a stretched state so that when the elastic layer is relaxed, the non-elastic material curls between the locations where it is bonded to the elastic layer. The resulting elastic composite material is stretchable to the extent that the non-elastic material curled between the bond locations allows the elastic layer to stretch. An example of this type of composite material is disclosed, for example, in U.S. Patent No. 4,720,415 to Vander Wielen et al., issued January 19, 1988.

In the composite of Vander Wielen et al., another elastic layer can be used instead of the non-elastic, shirrable material, so that the resulting composite can stretch in more than one direction. However, a composite formed from elastic layers alone would have the undesirable plastic-like or rubbery feel that was intended to be eliminated by making composites from elastic and non-elastic materials.

DEFINITIONS

The term "elastic" is used herein to describe any

Material that can be stretched by at least about 60 percent when a tension force is applied, i.e. is ductile (i.e. to a stretched, tensioned length of at least

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about 160 percent of its relaxed, unstretched length) and which has a recovery of at least 55 percent of its extension upon removal of the stretching, elongating force. A hypothetical example would be a one (1) inch sample of a material which is elongable to at least 1.60 inches and which recovers to a length of no more than 1.27 inches upon stretching to 1.60 inches and releasing the stress. Many elastic materials can be stretched much more than 60 percent (i.e., much more than 160 percent of their relaxed length), such as being stretched 100 percent or more, and many recover to substantially their initial relaxed length upon removal of the stretching force, for example, less than 105 percent of their initial relaxed length.

As used herein, the term "non-elastic" refers to any material that does not fall within the above definition of "elastic".

As used herein, the terms "recover" and "recovery" refer to the contraction of a stretched material upon termination of a tension force after stretching the material by applying the tension force. For example, if a material having a relaxed, unstretched length of one (1) inch is stretched by 50 percent by stretching to a length of one and one-half (1.5) inches, this means that the material has elongated by 50 percent (0.5 inches) and has a stretched length of 150 percent of its relaxed length. If this exemplary stretched material contracts, that is, recovers to a length of one and one-tenth (1.1) inches after the tension and stretch force is removed, the material would have recovered by 80 percent (0.4 inches) of its one-half (0.5) inch elongation. The recovery can be expressed as [(maximum stretch length - final sample length) / (maximum

¹ inch = 2.54 cm

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stretch length - initial sample length)] x 100.

As used herein, the term "nonwoven web" refers to a web having a structure of individual fibers or filaments laid but not in an identifiable, repeating manner. Nonwoven webs have been formed in the past by a variety of processes such as meltblowing processes, spunbonding processes and processes for making bonded carded nonwoven webs.

As used herein, the term "microfibers" refers to small diameter fibers having an average diameter of no greater than about 100 μm, for example, having an average diameter of about 0.5 μm to about 50 μm, and in particular, microfibers may have an average diameter of about 4 μm to about 40 μm.

As used herein, the term "meltblown fibers" refers to fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments in a high velocity gas (e.g., air) stream which attenuates the filaments of molten thermoplastic material to reduce their diameter even to a microfiber diameter. Thereafter, the meltblown fibers are conveyed by the high velocity gas stream and deposited on a collecting surface to form a web of randomly distributed meltblown fibers. Such a process is disclosed, for example, in U.S. Patent No. 3,849,241 to Butin, the disclosure of which is incorporated herein by reference.

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As used herein, the term

"spunbond fibers" means small diameter fibers formed by extruding a molten thermoplastic material as filaments from a plurality of fine, usually circular, capillaries of a spinneret, with the diameter of the extruded filaments then being rapidly reduced, for example, by eductive stretching or other well-known spunbonding mechanisms. The manufacture of spunbond nonwoven webs is shown in patents such as U.S. Patent No. 4,340,563 to Appel et al. and U.S. Patent No. 3,692,618 to Dorschner et al. The disclosures of both of these patents are incorporated herein by reference.

As used herein, the term "interfiber bond" refers to that bond created by entangling the individual fibers to form a coherent web structure without the use of thermal bonding. This entanglement of the fibers is inherent in meltblowing processes, but can be created or enhanced by processes such as hydraulic entangling or needling. Alternatively and/or additionally, a binder can be used to enhance the desired bond and maintain the coherent structure of a fibrous web. For example, powdered binders and chemical solvent bonding can be used.

As used herein, the term "layer" refers to a ply, which may be either a film or a nonwoven web.

As used herein, the term "dimension-reduced material" means any material that has been reduced in at least one dimension by the application of a tension force in

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a direction perpendicular to the desired direction of dimensional reduction. Methods that can be used for such contraction of a material include, for example, stretching processes.

As used herein, the term "dimension-reducible material" means any material that can be dimensionally reduced.

As used herein, the term "percent dimensional reduction" means the ratio determined by measuring the difference between the non-dimensionally reduced extent and the dimensionally reduced extent of the dimensionally reducible material and then dividing that difference by the non-dimensionally reduced extent of the dimensionally reducible material.

As used herein, the term "elastic composite material" refers to a multi-layered material capable of stretching and recovering in at least two directions and having at least one elastic layer joined to at least one reduced-dimensional material at at least three locations lying in a non-linear arrangement, the reduced-dimensional material being shirred between at least two of the locations where it is joined to the elastic layer. The elastic composite material of the present invention has stretching and recovering in at least one direction, for example, in the machine direction, to the extent that the wrinkles in the reduced-dimensional material allow the elastic material to stretch. The elastic composite material also has stretching and recovering in at least one other direction, for example, generally parallel to the

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1*5 :: :

shrinkage of the shrink-wrapped material (e.g., typically across the machine direction). The elastic composite material can be stretched in this direction to approximately the pre-shrinkage width of the shrink-wrapped material. The elastic composite material can recover to approximately its initial width (i.e., the shrink-wrapped width of the shrink-wrapped material) because recovery of the elastic layer causes recovery of the adherent shrink-wrapped material to its shrink-wrapped width.

As used herein, the term "elongation" or "percent elongation" means a ratio determined by measuring the difference between the stretched and unstretched length of an elastic material to a certain extent and dividing that difference by the unstretched length of the elastic material to the same extent.

As used herein, the term "superabsorbent" refers to absorbent materials capable of absorbing at least 5 grams of aqueous liquid per gram of absorbent material (e.g., more than 20 grams of distilled water per gram of absorbent material) while immersed in the liquid for 4 hours and retaining substantially all of the absorbed liquid under a compressive force of up to about 1.5 psi ² .

As used herein, the term "polymer" includes generally, but without limitation, homopolymers, copolymers, such as block, graft, random and alternating copolymers, terpolymers, etc., and blends and modifications thereof. Furthermore, unless specifically limited, the term "polymer" is intended to include all possible

² 1 psi = 0.069 bar

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geometric configurations of the material. These configurations include, without limitation, isotactic, syndiotactic and statistical symmetries.

As used herein, the term "consisting essentially of" does not exclude the presence of additional materials that do not significantly affect the desired properties of a particular composition or product. Exemplary materials of this type include, without limitation, pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, solvents, particulate materials, and materials added to improve the processability of the composition.

The innovation provides an elastic composite material according to independent claims 1 and 15, which is capable of stretching in at least two directions. Further advantageous features of the innovation emerge from the dependent claims, the description, the examples and drawings. The claims are to be understood as a first, non-limiting way of defining the innovation in general terms.

The present innovation creates elastic materials and in particular an elastic composite material containing at least one elastic layer.

The elastic composite material of the present innovation can be produced, for example, as follows:

Applying a clamping force to at least one dimensionally reducible material to reduce the dimension of the material;
35

Stretching an elastic layer;

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Connecting the stressed, dimensionally reduced material to the stretched elastic layer at at least three locations in a non-linear arrangement; and

Relaxing the stretched elastic layer so that the dimensionally reduced web is crimped between at least two of the locations.

The stressed, reduced-dimensional material may be bonded to the stretched elastic layer by overlaying the materials and applying heat and/or pressure to the overlaying materials. Alternatively, the layers may be bonded using other bonding methods and materials such as adhesives, pressure sensitive adhesives, ultrasonic welding, high energy electron beams and/or lasers.

The elastic layer used as a component of the elastic composite material may be a pressure-sensitive elastomeric adhesive layer. When the elastic layer is a nonwoven web of elastic fibers or pressure-sensitive elastomeric adhesive fibers, the fibers may be meltblown fibers. The meltblown fibers may include meltblown microfibers.

The reduced-size material used as a component of the elastic composite material is formed from a reducible material. The reducible material can be any material that can be reduced in size, including knitted fabrics, open weave fabrics and nonwoven webs. Reducible nonwoven webs include, for example,

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bonded carded webs, spunbonded webs, or meltblown fiber webs. The meltblown fibers may include meltblown microfibers. The size-reducible material may also comprise multiple layers, such as multiple spunbond layers and/or multiple meltblown layers. The size-reducible material may be comprised of polymers, such as polyolefins. Example polyolefins include polypropylene, polyethylene, polybutylene, ethylene copolymers, propylene copolymers, and butylene copolymers.

The reducible material can be reducible by applying a tension force in a direction perpendicular to the desired direction of reducibility. The reducible material is joined to a stretched elastic layer at at least three locations that are in a non-linear arrangement such that when the stretched elastic layer is relaxed, the reducible material is crimped between at least two of these locations.

The resulting elastic composite material exhibits stretch and recovery in at least one direction, such as the machine direction, to the extent that the wrinkles in the reduced-dimensional material permit stretching of the elastic material. The elastic composite material also exhibits stretch and recovery in at least one other direction, such as a direction generally parallel to the reduced-dimensional material. The reduced-dimensional material may be transverse to the machine direction, and the elastic composite material may be stretched in that direction, typically to about the initial width of the reduced-dimensional material. The

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The elastic composite material may recover to approximately its initial width (i.e., the reduced width of the reduced material) because recovery of the elastic layer causes recovery of the adherent reduced material to its reduced width.

Fig. 1 is a schematic representation of an exemplary process for forming an elastic composite material.

Fig. 2 is a top view of an exemplary reduced-dimensional material prior to stressing and dimension reduction.

Fig. 2A is a top view of an exemplary reduced-dimensional material.

Figure 2B is a top view of an exemplary elastic composite material while partially stretched.

Figure 3 is an illustration of an exemplary bonding pattern used to connect the components of an elastic composite material.

Referring to Figure 1 of the drawings, there is illustrated at 10 a method of forming an elastic composite material capable of stretching in at least two directions.

According to the present invention, a dimensionally reducible material 12 is unwound from a feed roller 14 and runs in the direction indicated by the arrows drawn therein, while the feed roller 14 rotates in the direction indicated by the arrows drawn therein.

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indicated by the arrow. The dimension-reducible material 12 runs through a roll gap 16 of a first S-roll arrangement 18, which is formed from the roll set 20 and 22.
5

The dimensionally reducible material 12 can be

known nonwoven extrusion processes, such as known meltblowing processes or known spunbonding processes, and passed directly through the nip 16 without first being stored on a feed roll.

An elastic layer 32 is unwound from a feed roll 34 and travels in the direction indicated by the arrow drawn thereon while the feed roll 34 rotates in the direction indicated by the arrows drawn thereon. The elastic layer travels through the nip 24 of a second S-roll assembly 26 formed by the set of rolls 28 and 30. The elastic layer 32 may be formed by extrusion processes such as melt blowing processes or film extrusion processes and passed directly through the nip 24 without first being supported on a feed roll.

The dimension-reducible material 12 runs through the roll gap 16 of the first S-roll arrangement 18 in an inverted S-path, as indicated by the direction of rotation arrows drawn on the roll sets 20 and 22. From the first S-roll arrangement 18, the dimension-reducible material 12 runs through the pressure roll gap 40, which is formed by the bonding rolls 42 and 44 of a bonding roll arrangement 46. At the same time, the elastic layer 32 runs through the roll gap 24 of the second S-roll arrangement 26 in an inverted S-path, as indicated by the direction of rotation arrows drawn on the roll sets 28 and 30. From the second

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■*

S-roll arrangement 26, the elastic layer 32 runs through the pressure roller gap 40, which is formed by the binding rollers 42 and 44 of a binding roller arrangement 46.

Since the linear peripheral speed of the rollers of the first S-roll arrangement 18 is regulated so that it is lower than the linear peripheral speed of the bonding rollers 42 and 44 of the bonding roller arrangement 46, the dimensionally reducible material 12 is held between the S-roll arrangement 18 and the pressure roller gap 40 of the

Λ*. Bonding roller assembly 46 is tensioned. In a similar manner, the peripheral linear speed of the rollers of the second S-roll assembly 26 is regulated to be less than the peripheral linear speed of the bonding rollers of the bonding roller assembly 46 so that the elastic layer 32 is tensioned between the second S-roll assembly 26 and the pressure roller nip 40 of the bonding roller assembly 46.

By adjusting the difference in the speed of the rollers, the reducible material 12 is tensioned to reduce the size to a desired extent and is maintained in such a tensioned, reducible state while the stretched elastic layer 32 is bonded to the reducible material 12 during passage through the bonding roller assembly 46 to form an elastic composite laminate 50 which is fed to a take-up roller 52 running at a peripheral linear speed approximately equal to or less than the peripheral linear speed of the bonding rollers 42 and 44. Alternatively, the elastic composite laminate 50 may be fed to a holding tank (not shown) where the stretched elastic layer 32 may contract and the reducible material 12 may curl.

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Other methods of tensioning the reduced-size material 12 may be used, such as stenters or other stretching arrangements that stretch the reducible material 12 in other directions, such as across the machine direction, and cause the reducible material 12 to be reduced in the vertical direction (e.g., in the machine direction).

Conventional drive means and other conventional devices which may be used in conjunction with the device of Fig. 1 are well known and are not shown in the schematic view of Fig. 1 for the sake of clarity.

When the bonding rolls 42 and 44 are heated bonding rolls that heat bond the reduced-size material 12 and the stretched elastic layer 32, it may be desirable to immediately direct the elastic composite material 50 after exiting the pressure nip 40 of the bonding roll assembly 46 to a holding vessel where the elastic composite material 50 is held in a relaxed, unstretched state long enough to cool the elastic layer sufficiently to prevent it from cooling in a tensioned state and thus losing all or part of its ability to contract from the stretched dimensions imparted to it during bonding. It has been found that elastic layers, particularly low basis weight elastic layers, can lose their ability to contract or return to their original unstretched dimensions if they are held under tension at or above their softening point for a significant period of time. A short recovery period in a relaxed, non-stretched state immediately after binding has proven to be beneficial

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proven to prevent contraction of the elastic layer with

low basis weight and a curling of the

dimensionally reduced material so that the

bound web has its elasticity in the direction and in the

dimensions that the dimensionally reduced material, the

is curled between the binding sites, allowing the elastic layer to stretch.

The dimensionally reducible material 12 may be a nonwoven material such as a spunbond web,

Mk can be meltblown web or bonded carded web.

When the dimensionally reducible material is a web of meltblown fibers, it may contain meltblown microfibers. The dimensionally reducible material 12 may be formed from fiber-forming polymers such as polyolefins. Exemplary polyolefins include one or more of polyethylene, polypropylene, polybutylene, poly(methylpentene), ethylene copolymers, propylene copolymers, and butylene copolymers. Suitable polypropylenes include, for example, polypropylene available from Himont Corporation under the trade designation PC-9 7 3, polypropylene available from Exxon Chemical Company under the trade designation Exxon 3445, and polypropylene available from Shell 5 Chemical Company under the trade designation DX 5AO 9.

In one embodiment of the present invention, the non-elastic, dimension-reducible material 12 is a multi-layer material comprising, for example, at least one layer of spunbond web bonded to at least one layer of meltblown web, bonded carded web, or other suitable material. For example, the dimension-reducible material 12 may be a multi-layer material comprising a first layer of spunbond polypropylene having a basis weight of

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·

about 0.2 to about 8 ounces per square yard (osy)3, a layer of meltblown polypropylene having a basis weight of about 0.2 to about 4 osy, and a second layer of spunbond polypropylene having a basis weight of about 0.2 to about 8 osy. Alternatively, the dimension-reducible material 12 may be a single layer of a material such as a spunbond web having a basis weight of about 0.2 to about 10 osy or a meltblown web having a basis weight of about 0.2 to about 8 osy.

The dimensionally reducible material 12 may also be a composite material consisting of a blend of two or more different fibers or a blend of fibers and particulate materials. Formation of such blends may be accomplished by adding fibers and/or particulate materials to the gas stream in which the meltblown fibers are conveyed so that intimate entanglement of the meltblown fibers with the other materials, such as pulp, staple fibers, and particulate materials such as hydrocolloid (hydrogel) particles, commonly referred to as superabsorbent materials, occurs prior to collecting the meltblown fibers on a collector to form a coherent web of randomly distributed meltblown fibers and other materials, as disclosed in U.S. Patent No. 4,100,324, the disclosure of which is incorporated herein by reference.

When the dimensionally reducible material 12 is a nonwoven web of fibers, the fibers should be bonded together by an interfiber bond to form a coherent web structure that can resist dimensionally reducibility. The interfiber bond may be formed by

1 ounce per square yard = 33.91 g/m ²

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Entanglement of the individual meltblown fibers. Fiber entanglement is inherent in the meltblowing process, but can be created or enhanced by processes such as hydraulic entanglement or needling. Alternatively and/or additionally, thermal bonding or a binder can be used to increase the desired coherence of the web structure.

The elastic layer 32 may be made of any material that can be manufactured in layer form.

jflk Generally, any suitable elastomeric fiber forming resins or blends containing the same can be used for the elastomeric fibers, threads, filaments and/or strands or the nonwoven webs of elastomeric fibers, threads, filaments and/or strands of the innovation, and any suitable elastomeric film forming resins or blends containing the same can be used for the elastomeric films of the innovation. Suitable elastic layers can have basis weights ranging from about 5 g/m ² (grams per square meter) to about 300 g/m ² , such as from about 5 g/m ² to about 150 g/m ² .

For example, the elastic layer 32 may be made from block copolymers of the general formula A-B-A', where A and A' are each a thermoplastic polymer end block containing a styrene portion such as a poly(vinylarene), and where B is an elastomeric polymer midblock such as a conjugated diene or a lower alkene polymer. For example, the elastic layer 32 may be formed from (polystyrene/poly(ethylenebutylene)/polystyrene) block copolymers available from Shell Chemical Company under the trademark KRATON G. Such a block copolymer may be, for example, KRATON™ G-1657.

Other exemplary elastomeric materials that may be used to form the elastic layer 32 include

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include elastomeric polyurethane materials such as those available under the trademark ESTANE from B.F. Goodrich & Co., elastomeric polyamide materials such as those available under the trademark PEBAX from the Rilsan Company, and elastomeric polyester materials such as those available under the trademark Hytrel from E. I. DuPont De Nemours & Company. The formation of elastic layers from elastic polyester materials is disclosed, for example, in U.S. Patent No. 4,741,949 to Morman et al., which is incorporated herein by reference. The elastic layer 32 may also be formed from elastic copolymers of ethylene and at least one vinyl monomer, such as vinyl acetates, unsaturated aliphatic monocarboxylic acids and esters of such monocarboxylic acids. The elastic copolymers and the formation of elastic layers from these elastic copolymers are disclosed, for example, in U.S. Patent No. 4,803,117.

Processing aids may be added to the elastomeric polymer. For example, a polyolefin may be blended with the elastomeric polymer (e.g., the A-B-A elastomeric block copolymer) to improve the processability of the composition. The polyolefin must be one that is extrudable in blended form with the elastomeric polymer when so blended and under a suitable combination of elevated pressure and elevated temperature conditions. Suitable polyolefin blend materials include, for example, polyethylene, polypropylene, and polybutene, including the ethylene copolymers, propylene copolymers, and butene copolymers. A particularly useful polyethylene can be obtained from the U.S.I. Chemical Company under the trade designation Petrothene NA 601 (also referred to herein as PE NA 601 or Polyethylene NA 601). Two or more polyolefins may be used. Extrudable blends of

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elastomeric polymers and polyolefins are disclosed, for example, in U.S. Patent No. 4,663,220 to Wisneski et al., which is incorporated herein by reference.

The elastic layer 32 may also be a pressure sensitive elastomeric adhesive layer. For example, the elastic material itself may be tacky, or alternatively, a compatible tackifying resin may be added to the extrudable elastomeric compositions described above to provide a

Mk elastomeric layer which can serve as a pressure sensitive adhesive, e.g., to bond the elastomeric layer to a tensioned, reversibly reduced-size non-elastic web. With respect to tackifying resins and tackified, extrudable elastomeric compositions, note the resins and compositions disclosed in U.S. Patent No. 4,787,699, which is incorporated herein by reference.

Any tackifying resin that is compatible with the elastomeric polymer and can withstand the high processing temperatures (e.g., extrusion temperatures) can be used. If the elastomeric polymer (e.g., the A-B-A elastomeric block copolymer) is blended with processing aids, such as polyolefins or extender oils, the tackifying resin should also be compatible with those processing aids. In general, hydrogenated hydrocarbon resins are preferred tackifying resins because of their better temperature stability. REGALREZ™ and ARKON™ P-series tackifying resins are examples of hydrogenated hydrocarbon resins. ZONATAK™ 501 lite is an example of a terpene hydrocarbon. REGALREZ™ hydrocarbon resins are available from Hercules Incorporated. ARKON™ resins

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P series are available from Arakawa Chemical (U.S.A.) Incorporated. Of course, the present innovation is not limited to the use of these three tackifying resins, and other tackifying resins that are compatible with the other ingredients of the composition and can withstand the high processing temperatures may be used.

For example, an elastomeric pressure sensitive adhesive may contain about 40 to about 80 percent by weight elastomeric polymer, about 5 to about 40 percent polyolefin, and about 5 to about 40 percent tackifying resin. For example, a particularly useful composition contained about 61 to about 65 percent by weight KRATON™ G-1657, about 17 to about 23 percent polyethylene NA 601, and about 15 to about 20 percent REGALREZ™ 1126.

The elastic layer 32 may also be a multi-layer material containing two or more individual coherent webs and/or films. Additionally, the elastic layer 32 may be a multi-layer material wherein one or more of the layers contain a mixture of elastic and non-elastic fibers or particulate materials. As an example of the latter type of elastic web, see U.S. Patent No. 4,209,563, which is incorporated herein by reference, wherein elastomeric and non-elastomeric fibers are entangled to form a single coherent web of randomly distributed fibers. Another example of such a composite elastic web would be that made by a technique disclosed in the previously cited U.S. Patent No. 4,741,949. The patent discloses a nonwoven elastic material containing a mixture of meltblown thermoplastic fibers and other materials. The fibers and other materials are combined in the gas stream in which the

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meltblown fibers such that intimate entanglement of the meltblown fibers with other materials, e.g., pulp, staple fibers, or particulate materials such as hydrocolloid (hydrogel) particles, commonly referred to as superabsorbents, occurs prior to collection of the fibers on a collection device to form a coherent web of randomly distributed fibers.

The bonding roll assembly 46 may be a patterned calender roll, such as a needle screen roll, arranged with a smooth backing roll. One or both of the calender roll and smooth backing roll may be heated, and the pressure between these two rolls may be adjusted by well known means to obtain the desired temperature, if necessary, and bonding pressure for bonding the tensioned, reduced-dimensional material 12 to the elastic layer 32 forming an elastic composite material 50.

Stressed reduced-dimensional materials may be bonded to the stressed elastic layer 32 at least three locations by any suitable means, for example, by thermal bonding or ultrasonic welding. The thermal and/or ultrasonic bonding techniques are believed to soften at least portions of at least one of the materials, typically the elastic layer, since the elastomeric materials used to form the elastic layer 32 have a lower softening point than the constituents of the reduced-dimensional material 12. The bond may be created by applying heat and/or pressure to the overlying stressed elastic layer 32 and the stressed reduced-dimensional material 12 by heating those portions (or the overlying layer) to at least the softening temperature of the material having the lowest softening temperature to

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to form a sufficiently strong and permanent bond between the resolidified softened parts of the elastic layer 32 and the dimensionally reduced material 12.

The stressed, reduced-dimensional materials should be bonded to the stressed elastic layer at at least three locations arranged so that when the stress force on the elastic layer is released, folds or wrinkles form in the reduced-dimensional material between at least two of the locations. In addition, the three locations should be arranged so that when the elastic composite material is stretched in a direction substantially parallel to the direction of dimension reduction (i.e., in a direction substantially perpendicular to the stress force applied to the reducible material during the dimension reduction process), the recovery of the elastic layer causes the reduced-dimensional material to recover to substantially its dimensionally reduced dimensions. The three or more locations should be in a non-linear arrangement, for example, to form a triangular or polygonal pattern of locations at which the reduced-dimensional material is bonded to the elastic layer.

With regard to thermal bonding, it is obvious to those skilled in the art that the temperature to which the materials or at least their bonding sites are heated for thermal bonding depends not only on the temperature of the heated roller(s) or other heat sources, but on the residence time of the materials on the heated surfaces, the basis weights of the materials and their specific heats and thermal conductivities. However, for a particular combination of materials and in view of the disclosure contained herein, the processing conditions required to achieve a

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required for satisfactory bonding can be easily determined.

Alternatively, the reduced-dimensional material 12 and the stressed elastic layer 32 may be joined using other bonding methods and materials, such as adhesives, pressure sensitive adhesives, solvent welding, hydraulic entanglement, high energy electron beams, and/or lasers.

Since the tensioned elastic layer 32 is connected to the dimensionally reduced material 12 and the dimensionally reduced material 12 can only be stretched in one direction (e.g.

To the extent that the reduced-dimensional material offers some resistance to puckering, the elastic layer is unable to fully recover to the unstretched dimension once bonded to the reduced-dimensional material. This requires that the length the elastic layer can stretch when bonded to the reduced-dimensional material be greater than the desired stretch of the elastic composite material in the direction in which the reduced-dimensional material cannot readily stretch (e.g., in the machine direction). If, for example, it is desired to produce an elastic composite material that can be stretched approximately 100 percent in the machine direction (i.e. to a length of approximately 200 percent of its initial relaxed length), a 100 cm length of elastic sheet can be stretched in the machine direction

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be stretched to a length of, for example, 220 cm (120 percent stretch) and bonded at at least three points (which are in a spaced non-linear arrangement) to a 220 cm length of reduced-dimensional material. The bonded elastic composite material is then relaxed and even if the elastic layer is able to recover to its original 100 cm length, the reduced-dimensional material bonded to it prevents complete recovery and the composite can relax to a length of, for example, 110 cm. Wrinkles and creases form in the reduced-dimensional material between at least two of the bonding points. The resulting 110 cm length of composite material is stretchable in the machine direction to a 220 cm length to obtain a composite material that can be stretched about 100 percent in the machine direction (i.e., can be stretched to a length that is about 200 percent of its original relaxed length). The initial length of the reduced-size material limits the achievable machine-direction elongation of the composite material in this hypothetical example because the reduced-size material acts as a "barrier" to prevent further or excessive stretching of the elastic layer in the machine direction under the action of elongation forces less than the ultimate tensile strength of the reduced-size shirred material.

The ratio between the original dimensions of the shrinkable material 12 and its dimensions after shrinking determines the approximate yield strengths of the elastic composite material in the direction of shrinking, typically transverse to the machine direction.

If it is desired to produce an elastic composite material which can be stretched in a direction generally parallel to the dimensional reduction of the

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For example, referring to Figs. 2, 2A and 2B, a width of a reducible material, shown schematically in Fig. 2 and not necessarily to scale, having a width "A" of, for example, 250 cm, is stretched to undergo dimension reduction to a narrower width "B" of about 100 cm, as shown in Fig. 2A. The clamping forces are shown as arrows C and C in Fig. 2A.

The tensioned, reduced-dimensional material is bonded to an elastic layer having approximately the same width "B" as the tensioned reduced-dimensional material and being stretchable in the cross-machine direction to at least approximately the same width "A" as the original dimension of the reduced-dimensional material prior to dimension reduction. The elastic layer may, for example, be approximately 100 cm wide and stretchable to a width of at least 250 cm. The stressed, reduced-size material shown in Figure 2A and the elastic layer (not shown) are superimposed and bonded at at least three spaced-apart locations in a non-linear arrangement while the elastic layer is maintained at a machine-direction elongation of about 120 percent (i.e., stretched about 220 percent of its original relaxed extent in the machine direction) since, as previously mentioned, the reduced-size material tends to prevent the elastic layer from fully contracting to its original machine-direction length.

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• * &igr; *

·

The bonded layers are relaxed, creating folds or wrinkles in the reduced-dimensional material between at least two of the bonding sites. The resulting elastic composite material, shown schematically and not necessarily to scale in Figure 2B, has a width "B" of about 100 cm and is stretchable to at least the original width "A" of 250 cm of the reduced-dimensional material with an elongation of about 150 percent (i.e., stretchable to about 250 percent of its original reduced-dimensional width "B"). The elastic composite material is capable of recovering to its original width "B" of about 100 cm because the recovery of the elastic layer to its original width "B" causes the adherent reduced-dimensional material to recover to its reduced-dimensional width "B". In addition, the elastic composite material is stretchable to approximately 100 percent in the machine direction, which is the extent to which the 0 wrinkles or folds in the reduced-size material allow the elastic layer to stretch in that direction. As can be seen from the example, the length that the elastic layer should be able to stretch across the machine direction before being bonded to the reduced-size material needs to be only as great as the length that the elastic composite material should stretch across the machine direction. However, as previously stated, the length that the elastic layer should stretch in the machine direction before being bonded to the reduced-size material should be greater than the length that the composite material should stretch in the machine direction.

The wrinkles in the reduced-dimensional material can allow the elastic composite material to stretch and recover in a direction in which

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·

In which the directions are not substantially parallel to the machine direction, for example in a direction deviating from the machine direction by about 45°. Likewise, the dimensional reduction of the dimensional reduced material may allow for stretching and recovery of the elastic composite material in a range of directions in which the directions are not substantially parallel to the direction of dimensional reduction, such as in a direction deviating from the direction of dimensional reduction by about 45°. Since the wrinkles in the dimensional reduced material and the direction of dimensional reduction can be aligned to allow for stretching and recovery in directions substantially perpendicular to each other, and since the wrinkles and the dimensional reduction allow for stretching and recovery in a range of directions, the elastic composite material may be capable of stretching and recovery in substantially all directions along the length and width of the material.

EXAMPLES 1-5

The elastic composite materials of Examples 1-5 were prepared by bonding an elastic layer to at least one dimensionally reduced material.

Tables I ₇ 4, 7, 10, 12 and 13 show the grab tensile test data for control specimens and elastic reduced bonded composite specimens. The grab tensile tests were conducted on an Instron Model 1122 Universal Testing Instrument constant strain increment tester using 4 inch by 6 inch specimens. The jaw faces of the tester were 1 inch by 1 inch and the cross yoke speed was set at 12 inches per minute. The following mechanical properties were determined for each specimen:

Maximum load, maximum total energy absorbed and maximum strain.

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31 μ· · ; ,' &iacgr;.·♦

The specimens were also cycled in the Instron Model 1122 with Microcon II - 50 kg load cell and the results are presented in Tables 1 through 13. In this cycle test, the jaw faces of the tester were 3 inches wide and 1 inch high (i.e., in the test direction) and so the specimens were cut to a size of 3 inches by 7 inches (i.e., 7 inches in the test direction) and individually weighed in grams. A 4 inch gauge length was used. The recording and cross yoke speeds were set at 20 inches per minute and the unit was zeroed, run in and calibrated using the standard procedure. The maximum strain limit for the cycle length was set at a distance determined by calculating 56 percent of the "elongation at break" after the grab tensile test. The specimens were pulled to the specified cycle length four times in the test cycle and then broken on the fifth cycle. The test equipment was set up to measure the peak load in pounds-force and the peak energy absorbed in inches-pounds-force per square inch^ on each cycle. On the fifth cycle (break cycle), the peak elongation, peak load and peak energy absorbed were measured. The area used in the energy measurements (i.e., the surface area of the test material) is the gauge length (four inches) times the specimen width (3 inches), which is 12 square inches. The results of the grab tensile tests and cycle tests were standardized for the measured basis weight.

Peak Total Energy Absorbed (TEA), as used in the examples and accompanying tables, is defined as the total energy under a load versus yield (load versus strain) curve to the "peak" or maximum load. TEA is defined in units of work/(length) ² or (pound-force * inch)/(inch) ² .

⁴ inch-pounds per square inch = 2.54 cm &khgr; 4,445N per 6,452 cm ²

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These values were standardized by dividing by the basis weight of the sample in ounces per square yard (osy), resulting in units of [(lbsf * inch)/inch ² ]/osy.

The ultimate load, as used in the examples and accompanying tables, is defined as the maximum load or force that will occur when the specimen is stretched to a specified extension or until it breaks. The ultimate load is expressed in units of force (lbsf) standardized for the basis weight of the material, resulting in a number expressed in units of lbsf/(osy).

Elongation or ultimate strain has the same general definition as previously given in the Definitions section and can be more precisely defined for the examples and accompanying tables as the relative increase in length of a specimen during tensile testing at maximum load. Ultimate strain is expressed as a percentage, i.e.

[{increase in length) / (original length)] x 100.

The set after a stretching cycle, as used in the examples and the accompanying tables, is defined as a ratio of the increase in length of the specimen after one cycle divided by the maximum elongation during the cycle test. The set is expressed as a percentage, i.e. [(final specimen length - initial specimen length) / (maximum elongation during the cycle test - initial specimen length)] × 100. The set is related to recovery by the expression [set = 100 recovery] when recovery is expressed as a percentage.

In Tables 2, 3, 5, 6, 8, 9 and 11 (which show the results of the cycle test), the value given for the set in the row "Set" and in the

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column headed "Tear" is the ultimate strain value (i.e., ultimate strain to break) measured during the fifth (final) stretch cycle. In these tables, the cycle test results reported in the "Tear" column for the elastomeric layer are the values read from the Instron test equipment when the elastomeric layer was stretched to the ultimate strain (i.e., the strain at maximum load when the specimen was tested to break) measured during the fifth (final) stretch cycle for the elastic composite containing that particular elastomeric layer.

example 1 Dimensionally reducible spunbond material

A dimensionally reducible web of conventionally produced spunbond polypropylene having a basis weight of approximately 0.4 ounces per square yard (osy) was tested on an Instron Model 1122 Universal Testing Instrument. The tensile test results for the spunbond web prior to dimension reduction are presented in Table 1 under the heading "Spunbond Control No. 1."

5 The total energy absorbed in the machine direction is given in the column of Table 1 with the heading "MD TEA" (Machine Direction Total Energy Absorbed). The maximum load in the machine direction is given in the column with the heading "MD Maximum Load". The maximum elongation in the machine direction is given in the column with the heading "MD Maximum Elongation". The total energy absorbed across the machine direction is given in the column with the heading "CD TEA" (Cross-Machine Direction Total Energy Absorbed). The maximum load across the machine direction is given in the column with the heading "CD

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The direction of travel is indicated in the column with the heading "CD

Maximum load" The maximum elongation across the

The direction of travel is indicated in the column with the heading "CD

Maximum elongation" (cross-machine direction).

Elastic layer

A blend of about 63 wt.% KRATON G-1657, 20% polyethylene NA-601, and 17% REGALREZ 112 6 having a melt flow of about 15 grams per ten minutes when measured at 19O ⁰ C and under a 2160 gram load; an elongation of about 750%; a strain number at 100% of about 175 psi; and a strain number at 300% of about 225 psi was formed into an elastic sheet of meltblown fibers using conventional meltblowing equipment with a recessed die tip. A four row meltblowing die assembly was operated under the following conditions: die area temperature of about 503 to about 548 ⁰ F^; die polymer melt temperature of about 491 to about 532 ⁰ F^; Primary air temperature of about 544 to about 557 ⁰ F ⁷ ; die inlet/tip pressure of about 85 to about 140 psig; forming wire vacuum of about 2 inches of water; vertical forming distance of about 11 inches; forming wire speed of about 61 feet per minute^ and winder speed of about 6 7 feet per minute. An elastic sheet of meltblown fibers having a basis weight of about 7 0 grams per square meter ( ^gsm ) was formed. The sheet was tested on the Instron Model 1122 Universal Testing Instrument and the results are shown in Table 1 under the heading "Elastomeric Control No. 1" and in Table 2 under the heading "Elastomeric Control No. 1".

⁵ about 260 ⁰ C to about 286°C

⁶ about 250 ⁰ C to about 277°C

⁷ about 2 82 ⁰ C to about 291 ⁰ C

⁸ one foot per minute = 0.305 m per minute

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Data shown in Table 2 for the last test cycle

(i.e., "tear") reported on "Elastic Control No. 1" were measured at the elongation at break of the elastic composite (i.e., "NSBL No. 1") containing the "Elastic Layer Control No. 1". For example, the elongation at break for "NSBL No. 1" in Table 2 is reported in the "tear" column and "set" row as 78 percent elongation, so this represents the elongation at which the data for "Elastomer Control No. 1" was measured during the last test cycle and which is reported in the "laminate tear" column.

Elastic composite material

The reducible spunbond polypropylene material having a basis weight of 0.4 osy was unwound from a first feed roll at an unwind speed set at about 10 feet per minute. The feed roll unwind slipped so that the unwind speed was measured at about 19 feet per minute (about 10% below the bonding roll speed). The elastic layer of meltblown fibers described above having a basis weight of about 70 grams per square meter was unwound from a second feed roll at an unwind speed of about 10 feet per minute. The elastic layer had a thin plastic film on one surface so that it would only adhere to an adjacent layer of material.

Both the reducible polypropylene material and the elastic meltblown layer were fed to a bonding roll assembly consisting of a smooth backing roll and an anilox calender roll in which the surface of the bonding rolls moved at a speed of about 21 feet/minute. The difference between the unwinding speed of 10 feet/minute and the

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Bonding roll speed of approximately 21 feet/minute tensioned both the reducible material and the elastic layer, resulting in elongation of both materials.
5

Fig. 3 shows the anilox calender roll pattern, magnified approximately five times. The anilox roll bond pattern had about 300 pins or bond points per square inch, giving a bond area of about 15 percent. The lines connecting the pins or bond points are drawn lines that are not present in the calender roll embossed pattern. The bond rolls were maintained at a temperature of about 127 ⁰ F, and the pressure in the nip between the two bond rolls was about 355 pounds per linear inch (pli)9. The composite was relaxed immediately after bonding.

The elastic composite material was tested on the Instron Model 1122 Universal Testing Instrument and the results are presented in Tables 1, 2 and 3 under the heading "NSBL No. 1".

Example 2

The reducible spunbond polypropylene material and the meltblown fiber elastic layer of Example 1 were bonded by the procedure of Example 1 except that the elastic layer was stretched slightly less and the spunbond material was stretched slightly more. The bonding roll speed was set at 21 feet per minute, the nip pressure was 355 pounds per linear inch, and the calender roll and backing roll temperatures were set at 127 ⁰ F. The elastic

⁹ 1 pound per linear inch = 0.4536 kg / 2.54 cm

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Layer was unwound from a feed roll at a speed of 14 feet per minute. The dimension-reducible spunbond polypropylene material was unwound from a feed roll. The unwind speed was set at a speed of about 14 feet per minute, but slippage occurred so that the unwind speed was measured at about 17 feet per minute, or about 20 percent below that of the bonding roll. The difference in speed provided a tension which caused the dimension-reducible material to be dimensionally reduced and the elastic material to be stretched before they were bonded by the bonding roll assembly.

The elastic composite material thus prepared was tested on the Instron Model 1122 Universal Testing Instrument and the results are shown in Tables 4, 5 and 6 under the heading "NSBL No. 2". Compared to the NSBL No. 1 material, the NSBL No. 2 material exhibits less elongation in the machine direction and greater elongation in the cross-machine direction.

Example 3

A sheet of the reducible spunbond polypropylene material having a basis weight of approximately 0.4 osy was prepared using conventional Lurgi spunbond process equipment. The grab tensile properties of the material were tested using an Instron Model 1122 Universal Testing Instrument and the results are shown in Table 7 under the heading "Spunbond Control No. 3".

A roll of this dimensionally reducible spunbonded polypropylene material with an initial

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* 5

width of about 32 inches was wound on a Camachine 10 rewinder manufactured by Cameron Machine Company, Brookland, New York. The take-up roll was operated at a speed of about 38 feet per minute, and the unwind roll was operated at a speed of about 35 feet per minute, reducing the material to a width of about 20 inches.

The roll of reducible spunbond polypropylene having a reduced width of about 20 inches was passed through the 22 Inch Face Pilot Coating Line manufactured by Black-Clawson Company, Fulton, New York. The unwind roll was operated at a speed of about 5 feet per minute and the take-up roll was operated at a speed of about 5 to about 8 feet per minute to further reduce the spunbond material to a final width of about 14 inches in dimension. The roll of reducible spunbond material was placed at the top of a three roll position unwinder. The roll of the elastic meltblown layer of Example 1 (i.e., the KRATON™ meltblown blend having a basis weight of 70 g/m ² ) was placed in the middle position. The bonding rolls ran at a speed of about 20 feet/minute and the unwind roll with the elastic layer ran at a speed of about 9 feet/minute. The unwind roll with the spunbond layer was set at a speed of about 11 feet/minute, but slippage occurred so that the unwind speed was measured at about 20 feet/minute, or about the same speed as the bonding rolls. However, sufficient tension was created to hold the reduced spunbond material in the reduced state.

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TO

The reduced spunbond material and the elastic meltblown layer were bonded using the heated bonding roll assembly of Example 1. The temperature of the calender roll and backing roll was set at 127 ⁰ F and the nip pressure was 355 pounds per linear inch.

The elastic, reduced-size bonded composite prepared in this manner was tested on the Instron Model 1122 Universal Testing Instrument and the results are shown in Tables 7, 8 and 9 under the heading "NSBL No. 3". Compared to the reduced-size spunbond control (Spunbond Control No. 3), all grab tensile test results for the elastic composite were lower, except for the machine direction and cross-machine direction elongation, which were significantly increased. Compared to the elastic meltblown layer (Elastomeric Control No. 1), the elastic composite exhibited approximately the same values during cycling testing but had a higher total absorbed energy and peak load at the break point of the elastic composite (Tables 8 and 9).

Example 4

An elastic reduced-size bonded composite material was prepared by bonding a layer of the reduced-size spunbond polypropylene material of Example 3 (Spunbond Control No. 3) to each side of the elastic meltblown layer of Example 1 (Elastomeric Control No. 1).

A first roll of the reduced-dimensional spunbond material was placed in the top position

·

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a three roll position unwinder. A second roll of 0.4 osy spunbond polypropylene having an initial width of about 32 inches was wound on a Camachine 10 rewinder manufactured by Cameron Machine Company, Brookland, New York. The take-up roll was operated at a speed of about 42 feet per minute and the unwind roll was operated at a speed of about 35 feet per minute, thereby reducing the material to a width of about 20 inches. The roll of spunbond polypropylene having a reduced width of about 20 inches was passed through the 22 Inch Face Pilot Coating Line manufactured by Black-Clawson Company, Fulton, New York. The unwind roll was operated at a speed of about 5 feet per minute and the takeup roll was operated at a speed of about 5 to about 8 feet per minute to further reduce the spunbond material to a final width of about 14 inches in dimension. The roll of reduced-dimension spunbond material was placed in the lowermost position of a three-roll position unwinder. A roll of the elastic meltblown material of Example 1 was placed in the middle position of the unwinder.

The reducible spunbond polypropylene materials and the elastic meltblown layer were bonded using the heated bonding roll assembly of Example 1. The unwind of the elastic layer was set at 12 feet per minute. The reducible spunbond polypropylene material was unwound from the feed rolls at a rate of about 21 feet per minute, creating sufficient tension to hold the reducible spunbond polypropylene in its reducible state. The

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Bonding roll speed was set at 23 feet per minute, nip pressure was 355 pounds per linear inch, and calender roll and backing roll temperature was set at 127 ⁰ F.
5

The elastic, reduced-size bonded composite material thus prepared was tested on the Instron Model 1122 Universal Testing Instrument. The grab tensile test results for the control materials and the elastic composite material are given in Tables 10 and 11 under the headings "Spunbond Control No. 3" and "Elastomeric Control No. 1" and "NSBL No. 4," respectively. The grab tensile test results for the elastic composite show less strength than the reduced-size spunbond control material, but greater strength than the elastomer. The cycle test data show that the composite material has a higher set than the elastomer, but a much higher total absorbed energy 0 and peak load during the final cycle in which it was stretched to break.

Comparison example 4

An elastic composite material was prepared in which a layer of the reduced-size spunbond polypropylene material of Example 4 was bonded to each side of the elastic meltblown layer of Example 4, except that the elastic layer was not stretched while being bonded to the reduced-size spunbond polypropylene.

The reduced-size spunbonded polypropylene material and the meltblown elastic

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Layers were bonded using the heated bonding roll assembly of Example 1. The bonding roll speed was set at 18 feet per minute, the nip pressure was 355 pounds per linear inch, and the temperature of the calender roll and backing roll was set at 127 ⁰ F. The unwinding of the elastic layer was set at 21 feet per minute so that there was no tension in the elastic web. The dimensionally reduced spunbonded

Polypropylene materials were unwound at about 19 feet per minute to create sufficient tension to hold the spunbond materials in the reduced-size condition. As a result, the reduced-size spunbond materials did not form any wrinkles or folds after being bonded to the elastic layer because the elastic layer was not held in a tensioned condition while the two layers were bonded.

The resulting elastic composite was tested on the Instron Model 1122 Universal Testing Instrument and the results are shown in Table 12 under the heading "Composite No. 4". Compared to NSBL No. 4, which was made with the same materials under the same process conditions, except that the elastic meltblown layer was stretched while bonding to the spunbond layers, the properties of Composite No. 4 did not change significantly, except that the cross-machine elongation was greater for Composite No. 4 and the machine elongation was greater for NSBL No. 4.

Example 5

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The reducible spunbond polypropylene material and the skewblown fiber elastic layer of Example 1 (i.e., Spunbond Control No. 1 and Elastomeric Control No. 1) were bonded by the procedure of Example 1. The bonding roll speed was set at 21 feet per minute, the nip pressure was 355 pounds per linear inch, and the temperature of the calender roll and backing roll was set at 127 ^° F. The elastic layer was unwound from a feed roll at a speed of 14 feet per minute. The reducible spunbond polypropylene material was unwound from a feed roll. The unwind speed was set at a speed of about 14 feet per minute, but slippage occurred so that the unwind speed measured about 17 feet per minute, or about 20 percent slower than the bonding roll. The speed difference created a stress that caused a dimensional reduction of the reducible material and an elongation of the elastic material prior to their bonding by the bonding roller assembly.

w The elastic material produced in this way

Composite material was tested on the Instron Model 1122 Universal Testing Instrument and the results are presented in Table 13 under the heading "NSBL No. 5".

Comparison example 5

The dimension-reducing spunbond

Polypropylene material and the elastic layer of meltblown fibers used in Example 5 (i.e., Spunbond Control No. 1 and Elastomeric Control No. 1) were prepared according to the procedure of Example 5

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bonded, except that the elastomer unwind was set at the same speed as the bonding rolls so that the elastomer was not stretched while being bonded to the reduced size spunbond material. The bonding roll speed was set at 21 feet per minute, the nip pressure was 355 pounds per linear inch, and the temperature of the calender roll and backing roll were set at 127 ⁰ F. The elastic layer was unwound from a feed roll at a speed of 21 feet per minute. The reduced size spunbond polypropylene material was unwound from a feed roll. The unwind speed of the feed roll for the spunbond material was set at a speed of about 14 feet per minute, but slippage occurred so that the unwind speed was measured at about 17 feet per minute, or about 20 percent slower than the bonding roll.

The composite material thus prepared was tested on the Instron Model 1122 Universal Testing Instrument and the results are shown in Table 13 under the heading "Composite No. 5." Compared to the NSBL No. 5 material, the composite No. 5 material had similar values for peak load and total energy absorbed, higher values for cross-machine stretch and lower values for machine-direction stretch.

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TABEL

Spunbond Control No.1

Elastomer Control No.1

NSBL No.1

MD TEA MD Maximum load MD Maximum elongation CD TEA CD Maximum load CD Maximum elongation

0.88 ± 0.26 15.9 ± 3.8 37 ± 5

0.90 ± 0.36 12.7 ± 2.8 51 ± 8

1.12 ± 0.34 1.54 ± 0.17

427 ± 93 0.83 ± 0.03 1.22 ± 0.05

407 ± 17

0.31 ± 0.07 2.87 ± 0.35 135 ± 0.30 ± 0.08 3.12 ± 0.48 85 ±

TABEL

CYCLE

Tear

Elastomer Control No. 1, cross-machine cycle test at 50% CD

strain 0.025 + 0.020 ± 0.020 ± 0.019 + 0.052 Höchst TEA 0.001 0.002 0.001 0.001 0.003 0.303 ± 0.287 ± 0.282 ± 0.278 ± 0.405 Maximum load 0.013 0.014 0.013 0.013 0.018 7.6 ± 0. 6 8.2 ± 0. 6 ■ 8.9 +0 8.9 ± 0 Deformation

rest

CYCLE 1 2_ 3 4_ Tear

NSBL No. 1 , cycle test across the machine direction to 48% CD elongation

Maximum TEA 0.15 ± 0.08 0.07 + 0.03 0.06 ± 0.06 ± 0.02 0.353 ±

0.03 0.123

Maximum load 2.5 ± 1.0 2.21 ± 1.0 2.10 ± 0.9 2.0 ± 0.9 3.8 ± 0.7

Deformation 11 ±4 13 ±4 18 ±2 18 ±2 78 ±18 rest

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TABLE 3

CYCLE

Tear

Elastomer Control Mr. 1 , Cycle Test in the Machine Direction to 75% MD Elongation Maximum TEA 0.10 ± 0.07 ± 0.002 0.064 ± 0.062 ± 0.197 ±

0.003 0.002 0.002 0.00S

Maximum load 0.616 ± 0.02 0.57 ± 0.02 0.56 ± 0.02 0.55 ± 0.02 0.763 ± 0.02 Deformation 7 ±0.7 8 ±0 8.7 +0.4 9.2 ±0 rest

CYCLE 112 1 Tearing

NSBL No. 1 , cycle test in the running direction to 76% MD elongation

Maximum TEA 0.065 ± 0.046 ± 0.044 ± 0.043 ± 4.56 +

0.008 0.005 0.005 0.005 0.08

Maximum load 0.538 ± 0.20 0.50 ± 0.18 0.48 ± 0.18 0.47 ± 0.17 3.7 ± 0.5

Deformation 5 ±1 6 ±1 7 ±1 9 ±1 130+8 rest

TABLE 4

MD TEA MD Maximum load MD Maximum elongation CD TEA CD Maximum load CD Maximum elongation

NSBL No. 1
0.31 ± 0.07
2.87 ± 0.35

135 ± 14
0.30 ± 0.08
3.12 ± 0.48
85 ± 12

NSBL No. 2 0.39 (only one reading)

3.8 ± 0.6 94 ± 5 0.37 ± 0.07

3.0 + 0.3 151 ± 20

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TABLE 5

CYCLE III Tear

Elastomer Control No. 1 , Cycle test across the machine direction to 90% CD elongation

Maximum TEA 0.08 ± 0.01 0.06 ± 0.006 0.054 ± 0.05 ± 0.005 0.21 ± 0.01

0.005

Maximum load 0.46 ± 0.04 0.43 + 0.03 0.42 ± 0.03 0.41 ± 0.03 0.63 ± 0.04 Deformation 7 ±1 9 ±1 9 ±1 9 ±1 rest

CYCLE 1 2 3 4. Tearing

NSBL Mr. 2 , cycle test across the machine direction to 90% CD elongation

Maximum TEA 0.097 ± 0.01 0.052 ± 0.05 ± 0.046 ± 0.74 ±

0.007 0.006 0.006 0.15

Maximum load 0.78 + 0.27 0.69 ± 0.66 ± 0.25 0.64 ± 3.59 ±

0.25 0.23 0.36

Deformation 9 ±2 11 ±2 12 ±2 16 ±3 177 ± 18 rest

TABLE 6

CYCLE 1 2 3 £ Snatch

Elastomer Control No. 1 , cycle test in the machine direction to 60% MD elongation

Maximum TEA 0.07 ± 0.002 0.05 ± 0.05 ± 0.001 0.045 + 0.103 ±

0.002 0.002 0.002

Maximum load 0.55 + 0.01 0.52 ± 0.01 0.50 ± 0.01 0.50 ± 0.01 0.652 ± 0.01

Deformation 7 ±0 8 ±0 9 +1 9 ±1 rest

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CYCLE 1 2_ 2 1 Tear

MSBL Mr. 2 , cycle test in the running direction to 63% MD elongation

Maximum TEA 0.177 ± 0.05 0.104 ± 0.10 ± 0.02 0.09 ± 0.01 0.49 ± 0.1

0.02

Maximum load 3.55 ± 0.6 3.2 ± 0.5 3.1 ± 0.4 3.0 ± 0.4 5.5 ± 0.7

Deformation 9 ±2 11 ±3 11 ±3 14 ±4 88 ±4 rest

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TABEL

Spunbond Control No.3

Elastomer Control No.1

NSBL No.3

MD TEA MD Maximum load MD Maximum elongation CD TEA CD Maximum load CD Maximum elongation

0.57 ± 0.18 13.8 ± 1.5 31 ±5

0.69 + 0.13 12.4 ± 2.3 42 +3

1.12 ± 0.34 1.54 ± 0.17

427 ± 93 0.83 + 0.03 1.22 ± 0.05

407 + 17

0.23 ± 0.001 2.66 ± 0.23

141 ± 0.38 ± 0.01 2.6 ± 0.2

176 ±

TABEL

CYCLE 1 2 3_ &iacgr; Tear

NSBL No. 3 , cycle test across the machine direction to 114% CD elongation

Maximum TEA 0.131 ± 0.066 ± 0.061 ± 0.058 ± 0.51

0.02 0.004 0.003 0.003 0.17

Maximum load 0.90 ± 0.79 ± 0.75 ± 0.72 ± 3.16

0.24 0.20 0.19 0.18 0.74

Deformation 11 ±1 13 ±2 14 ±2 16 ±2 172 rest

±

CYCLE

Tear

Elastomer Control No. 1 , Cycle Test Cross-Direction to 114% CD

strain

Maximum TEA 0.14 ± 0.002 0.09 ± 0.001 0.09 ± 0.08 ± 0.20 ± 0.002

0.001 0.001

Maximum load 0.57 ± 0.005 0.53 ± 0.003 0.52 ± 0.51 ± 0.68 ± 0.01

0.005 0.004

Deformation 8 ±0 9 ±0.5 10 ± 0.5 10 ±0.5 rest

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so

TABLE 9

CYCLE LiIl Tear

MSBL No. 3 , cycle test in the running direction to 97% MD elongation

Maximum TEA 0.083 ± 0.059 + 0.057 ± 0.056 ± 0.493 ±

0.008 0.005 0.005 0.004 0.14

Maximum load 0.76 ± 0.34 0.67 ± 0.29 0.67 ± 0.30 0.65 ± 0.28 4.73 ±

0.40

Deformation 4.4 ± 1.1 5.2 ± 1.1 6.0 ± 1.2 9.0 ± 2.3 137 ± 7 residual

CYCLE

Tear

Elastomer Control No. 1 , cycle test in the running direction to 97% MD

strain

Maximum TEA 0.15 ± 0.01 0.10 ± 0.005 0.09 ± 0.004 0.089 ± 0.184 ± 0.01

0.004

Maximum load 0.7 ± 0.03 0.65 ± 0.03 0.63 ± 0.03 0.62 ± 0.03 0.786 ± 0.03

Deformation 7±0 8±0 9±0 9 ±0 rest

TABLE 10

Spider-Found Control No.3

Elastomer Control No. 1

NSBL No. 4 Control No. 4

MD TEA MD maximum load MD maximum elongation CD TEA CD maximum load CD maximum elongation

0.57 ± 0.18 13.8 ± 1.5 31 ± 5

0.69 ± 0.13 12.4 ± 2.3 42 ±3

1.12 ± 0.34 1.54 + 0.17

427 + 93 0.83 ± 0.03 1.22 ± 0.05

407 ± 17

0.38 ± 0.07

4.2 ± 0.6

130 ± 11

0.52 ± 0.09

3.6 + 0.5

160 ± 11

TABLE 11

CYCLE 112 1 Tearing

NSBL No. 4 , cycle test across the machine direction to 90% CD elongation

Maximum TEA 0.17 ± 0.03 0.0 65 ±0.06 ±0.05 ± 0.72 ±

0.007 0.005 0.005 0.21

Maximum load 1.67 ± 0.30 1.43 ± 1.33 ± 0.23 1.28 ± 0.24 4.62 ±

0.26 0.84

Deformation 18 ±3 20 ±3 21 ±3 24 ±3 151 ±14 rest

CYCLE

Tear

Elastomer Control No. 1 , Cycle Test Cross-Direction to 90% CD

strain

Maximum TEA 0.086 ± 0.06 ± 0.004 0.0S ± 0.003 0.055 ± 0.161 ± 0.01

0.005 0.003

Maximum load 0.478 ± 0.02 0.45 ± 0.02 0.43 ± 0.02 0.42 ± 0.02 0.598 ± 0.03

Deformation 7.5 ±0.3 8 ±0.3 9.6 ± 0.3 9.8 ±0 rest

TABLE 12

MD TEA MD Maximum load MD Maximum elongation CD TEA CD Maximum load CD Maximum elongation

Composite No. 4

0.33 ± 0.06

5.8 ± 0.5 48 ±4

0.6 ± 0.1

3.1 ± 0.5
229 ± 12

NSBL No. 4

0.38 ± 0.07 4.2 ± 0.6

130 ± 11

0.5 ± 0.1 3.6 ± 0.5

160 ± 11

► «·

&bull; <

TABLE 13

Grab tensile test:

MD TEA MD Maximum load MD Elongation CD TEA CD Maximum load CD Elongation

Composite No. 5 0.35 ± 0.05 4.57 ± 0.21 50 ±5 0.54 ± 0.15 2.45 ± 0.31

217 ± 23

NSBL No. 5 0.39 (only one test) 3.8 + 0.6 ±5 0.37 ± 0.07 3.0 ± 0.3 ± 20

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RELATED APPLICATIONS

This application is one in a group of commonly assigned patent applications filed on the same date. The group includes the present application and application USSN 07/451,281 in the name of Michael T. Morman entitled "Multi-Direction Stretch Composite Elastic Material Including a Reversibly Necked Material". The subject matter of that application is incorporated herein by reference.

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Claims (15)

Protection claims 1. An elastic composite material capable of stretching in at least two directions, comprising: at least one elastic layer; and at least one reduced-dimensional material bonded to the elastic layer at at least three locations arranged in a non-linear arrangement, the reduced-dimensional material being crimped between at least two of these locations. 2. The material of claim 1, wherein the elastic layer comprises an elastomeric polymer selected from the group consisting of elastic polyesters, elastic polyurethanes, elastic polyamides, elastic copolymers of ethylene and at least one vinyl monomer, and elastic A-B-A' block copolymers, wherein A and A' are the same or different thermoplastic polymers and wherein B is an elastomeric polymer block. 3. The material of claim 1 or 2, wherein the elastic layer is an elastic web of meltblown fibers. 4. Material according to one of the preceding claims, wherein the elastic layer is a pressure sensitive elastomeric adhesive layer. 5. The material of claim 4, wherein the pressure sensitive elastomeric adhesive layer is formed from a blend of an elastomeric polymer and a tackifying resin. M:\TEXT\GBM\535GDEEE.DOC 6. The material of claim 5, wherein the mixture further contains a processing aid. 7. The material of claim 4, wherein the pressure sensitive elastomeric adhesive layer is a pressure sensitive elastomeric adhesive web of meltblown fibers. 8. Material according to one of claims 2 to 7, wherein the elastomeric polymer is mixed with a processing aid. 9. The material of any one of claims 3 to 8, wherein the web of meltblown fibers contains microfibers. 10. Material according to one of the preceding claims, wherein the dimensionally reduced material is a material selected from the group consisting of fabrics, open weave fabrics, nonwovens and/or composite materials comprising a mixture of fibers and one or more other materials selected from the group consisting of cellulose, staple fibers, particulate materials and superabsorbent materials. 11. The material of claim 10, wherein the nonwoven material is a web selected from the group consisting of a bonded carded fiber web, a spunbond fiber web, a meltblown fiber web, and a multilayer material containing at least one of the webs. M:\TEXT\GBM\535ODEEE.DOC 12. Material according to claim 10 or 11, wherein the fibers comprise a polymer selected from the group consisting of polyolefins, polyesters and polyamides. 13. The material of claim 12, wherein the polyolefin is selected from the group consisting of one or more of polyethylene, polypropylene, polybutylene, ethylene copolymers, propylene copolymers, and butylene copolymers. 14. The material of any one of claims 11 to 13, wherein the web of meltblown fibers contains microfibers. 15. Elastic composite material, in particular according to one of the preceding claims, which is stretchable in at least two directions, comprising: at least one elastic layer of meltblown fibers; and at least one dimensionally reduced nonwoven web of polypropylene fibers bonded to the elastic layer at at least three locations located in a non-linear arrangement, the dimensionally reduced web being crimped between at least two of these locations. MATEXT\GBM\5350DEEE.DOC