MXPA99009709A - Method for making a stable web having enhanced extensibility in multiple directions - Google Patents

Abstract

The present invention provides a stable material having enhanced extensibility and a method for making the same. A tensioning force is applied to the neckable material to neck the material in a direction perpendicular to the first direction. The necked material is then subjected to mechanical stabilization to provide a stabilized extensible necked material. The stabilized extensible necked material is then passed between the peripheral surface of a cylinder which is driven in rotating motion and a device for pressing the stabilized extensible necked material against the peripheral surface of the cylinder. A retarding member retards the passage of the stabilized extensible necked material and directs the material away from the peripheral surface of the cylinder. The stabilized extensible necked material is easily extended in a direction parallel to the first direction and perpendicular to the first direction.

Description

METHOD FOR DEVELOPING A STABLE FRAME THAT HAS EXTENSION CAPACITY ACCREDITED IN MULTIPLE ADDRESSES FIELD OF THE INVENTION The present invention relates to stable materials having increased spreading capacity in multiple directions and a subsequent mechanical processing method to form them. High-extension materials, such as non-woven wefts and film wefts are particularly well suited for use in disposable absorbent articles such as diapers, incontinence briefs, training pants, feminine hygiene garments, and the like, since that these are capable of being used in parts of the article where of the high extension capacity can help in the adjustment of the articles to the body.

BACKGROUND OF THE INVENTION Non-woven wefts can be manufactured in products and product components in a way that is not expensive than products that can be seen as disposable after only use or for some uses. Representatives of these products include diapers, training pants, towels, garments, incontinence briefs, feminine hygiene garments and the like. The non-woven webs can be treated to provide the non-woven web with certain properties. For example, U.S. Patent No. 5,244,482 issued to Hassenboehler, Jr., et al. On September 14, 1993, discloses a method for treating a non-woven web wherein the non-woven web is heated to a high temperature and stretched to a non-woven web. uniaxial way to consolidate and stabilize the nonwoven web. These non-woven webs are noted for exhibiting an increased elasticity after processing. This increase in elasticity is recognized by knowing caused by the new "memory" infused by the heating of the nonwoven web. For applications where increased extensibility rather than elasticity is desired, this heating is therefore undesirable. Additionally, such stretching and hardening of the non-woven web that by heating even at elevated temperature often causes the brittleness of the fiber and the non-woven web exhibits increased brightness. For many applications involving contact with the skin, for example, such as in the diaper cover material, which attributes are contrary to similar properties. to the desired fabric of softness and non-plastic appearance (low gloss). Finally, the requirement to heat the nonwoven web to consolidate the weft adds to the complexity and cost of the process. U.S. Patent No. 4,981,747 issued to Morman on January 1, 1991 discloses a material "reversibly constricted". It is taught that the unstabilized tapered material must be maintained under high tension on a rewinding roll until such time that while the additional thermal hardening step is performed to stabilize the material. This material will again suffer from the deficits noted above with respect to the preferred skin contact applications, and will increase the elastic properties of the material rather than the extensible behavior of the material. U.S. Patent No. 5,226,992 issued to Morman on July 13, 1993, discloses a method for producing a composite elastic composite bonded material. A tensile force is applied to at least one material capable of tapering, such as a nonwoven web capable of tapering, to constrict or consolidate the material. Instead of heating the consolidated non-woven web, this patent teaches overlaying the consolidated, tensioned non-woven web on an elastic material and joining the consolidated, tensioned non-woven web to the elastic material while the consolidated, tensioned non-woven web is in an unstressed condition. Joining the consolidated, tensioned non-woven fabric to the elastic material while still in a stretched condition, the nonwoven web is restricted to its narrowed dimension. This method does not provide a means to produce a stabilized stretchable web without attaching the nonwoven web to an additional elastic layer. It is an object of the present invention to provide a stabilized extendable tapered non-woven web, capable of being wound into a stable roll material or in the affixed form for subsequent conversion or combination operations. It is also an object of the present invention to provide a stabilized stretchable non-woven web, capable of extension at very high speeds via mechanical tensioning means. It is also an object of the present invention to provide a post-processing method for producing a stretched, stabilized, stretched material. It is also an object of the present invention to provide a post-processing method for producing a stretched, stabilized constricted material, which does not require heating of the material capable of shaking at elevated temperatures, to increase the extensible properties instead of the elastic properties. and to substantially preserve the original properties of the non-woven web capable of narrowing. It is also another object of the present invention to provide a stabilized extensible material which can be easily spread in multiple directions. As used herein, the term "elastic" refers to any material which, when applying a torsional force, is capable of stretching, that is, capable of elongation, to at least about 60% (i.e. , at a stretched, twisted length, which is at least approximately 160% of its relaxed length without twisting), and which, will recover at least 55% of its elongation by releasing the stretching force, elongation. As used herein, the term "extensible" refers to any material which, when applying a torsional force, is capable of stretching, that is, capable of elongation, to at least 60% without suffering catastrophic failure (it is say, at a stretched, twisted length, which is at least about 160% of its relaxed length without twisting), but does not recover more than 55% of its elongation upon release of the stretching force, than elongation. As used herein, the term "highly extensible" refers to any material that, upon application of a torsional force, is capable of stretching, that is, capable of elongation, to at least about 100% without suffering catastrophic failure. (ie, at a stretched, twisted length, which is at least approximately 200% of its relaxed length without twisting), but does not recover more than 55% of its elongation upon release of the stretching force, elongation. As used herein, the term "stabilized" refers to material of the present invention that is capable of being stored in a stable condition in any common or conventional raster storage manner without the need for further heating or addition of or join with other frames to stabilize the material. This storage medium would include, for example, low voltage rollers or boxed material. We are used here, the term "nonwoven weft", refers to a weft that has a structure of individual fibers or threads which are placed internally, but I have not in any regular repeating way. The nonwoven webs have been, in the past, formed by the variety of processes such as, for example, melt blowing processes, stick spinning processes, and linked carded web processes.

As used herein, the term "constricted material" refers to any material that has been restricted in at least one dimension by the application of a tension force in a direction that is perpendicular to the desired direction of the constriction. As used herein, the term "material capable of narrowing" refers to any material that can be constricted. As used herein, the term "constriction percent" refers to the ratio determined by measuring the difference between the non-constricted dimension and the stabilized constricted dimensions of the material capable of tapering in the direction of! narrowing, and then divide that difference by the dimension without narrowing of! material capable of narrowing, then multiplying it by 100. As used herein, the term "composite elastic material" refers to a material comprising an elastic member attached to a stabilized, stretched, stretched material. The elastic member may be attached to the stretched, stabilized constricted material at intermediate points or may be continuously attached thereto. The joint is achieved while the elastic member and the stretched, stabilized constricted material are in a juxtaposed configuration. The composite elastic material is elastic in a direction generally parallel to the direction of the constriction of the stretched, stabilized constricted material, and can be stretched in that direction to the point of rupture of the stabilized, stretched constricted material. A composite elastic material may include more than two layers. As used herein, the term "polymer" generally includes, but is not limited to, homopolymers, copolymers, such as, for example, block, graft, random, and alternating copolymers, terpolymers, etc., and mixtures and modifications thereof. In addition, unless specifically limited in another way, the term "polymer" must include all configurations of molecular geometry of the material. These configurations include, but are not limited to, isotactic, syndiotactic or random symmetries. As used herein, the term "surface path length" refers to a measurement along the topographic surface of the material in question in a specific direction.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention, there is provided here a method of producing a stabilized stretchable, non-woven web, comprising the steps of: providing a material capable of shaping; feed the material capable of narrowing in a first direction; applying a tension force to the material capable of tapering to constrict the material in a direction parallel to the first direction; subjecting the material capable of narrowing to mechanical stabilization to provide a material capable of stretching, stabilized; passing the stretchable, stabilizing material stabilized between a peripheral surface of a cylinder, which is driven in rotary motion and a device for pressing the extensible stabilizing material, stabilized, against the peripheral surface of the rotating cylinder; retarding the passage of extensible stabilized material, stabilized, by a delay member; and direct the material capable of stretching, stabilized, far away from the peripheral surface of the cylinder.

Preferably, the material is directed away from the peripheral surface of the cylinder by the delay member to a surface from which an acute angle is formed with the peripheral surface of the cylinder in the direction of rotation of the cylinder. The stretchable, stabilized narrowing material is easily spread on both in a direction parallel to the first direction and in a direction perpendicular to the first direction. A preferred method for mechanically stabilizing the constricted material comprises subjecting the constricted material to incremental stretching in a direction generally perpendicular to the direction of narrowing. The method may also comprise the additional step of winding the stretchable tapered material, stabilized, on an intake roller or affixing the stretched, stabilized, stretched material in the box. The method may also comprise the additional step of attaching the stabilized stretchable tapered material to an elastic member to form a composite elastic material. If the material is capable of stretching, it can be narrowed by stretching in a direction generally perpendicular to the desired direction of narrowing. The material capable of narrowing can be any material that can be narrowed sufficiently at room temperature. Suitable narrowing materials include loose and knitted woven fabrics, carded bonded nonwoven webs, spunbonded non-woven webs, or non-woven webs blown under melting. The narrowing material can also have multiple layers such as, for example, multiple spunbonded layers and / or multiple layers blown under melt or layers of films. The narrowing material can be made of polymers such as, for example, polyolefins. Exemplary polyolefins include polypropylene, polyethylene, ethylene copolymers, propylene copolymers, and mixtures thereof. The material capable of tapering may be a non-elastic material such as, for example, a non-elastic non-woven material.

BRIEF DESCRIPTION OF THE DRAWINGS While the description concludes with the claims pointing out in a particular manner and claiming differently the subject matter, which is considered as formant of the present invention, it is believed that the invention will be better understood from the following description which it is taken in combination with the drawings that accompany it, the. which similar designations are employed to designate substantially identical elements, and in which: Figure 1 is a schematic illustration of an exemplary process for forming a tapered material of the present invention. Figure 2 is an enlarged perspective illustration of the stabilizer roller arrangement. Figure 3 is an enlarged, perspective illustration of the micrexing apparatus. .. - Figure 4 is a plan view of the material capable of shaping specimen before tightening and tapering. Figure 5 is a plan view of an exemplary tapered material. Figure 6 is a plan view of an exemplary composite elastic material while partially stretched. Figure 7 is a schematic illustration of another exemplary process for forming a tapered material of the present invention. Figure 8 is a plan view of a separate enhancement pattern which is not suitable for placing the constricted material.

Figure 9 is a plan view of an embossing pattern of the present invention that is suitable for positioning the constricted material. Figure 10 is a plan view of another emboss pattern of the present invention that is suitable for positioning the constricted material.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figure 1, there is illustrated schematically at 10 a process for forming a stretched, stabilized constricted material of the present invention. According to the present invention, a shrinkable material 22 is unwound from a supply roll 23 and travels in the direction indicated by the arrows associated therewith as the supply roll 23 rotates in the direction indicated by the arrows associated with it. The travel direction of the tapered material 22 is the address of the machine or first address. The constricted material 22 passes through a gripping space 25 of the S-roller arrangement 26 formed by the multiple rollers 28 and 30. The shrinkable material 22 can be formed by known non-woven extrusion processes, such such as, for example, known meltblown processes or known spunbond processes, and passed directly through the grip space 25 without first being stored on a supply roll. The narrow-able material 22 passes through the gripping space 25 of the roll arrangement arrangement at S 26 on the reverse S path as indicated by the arrows in the direction of rotation associated with the multiple rolls 28 and 30. A Starting from the arrangement of the S-roll 26, the narrow-able material 22 passes through the gripping space 32 formed by the incremental stretching rollers 34 and 36 of the mechanical stabilization arrangement 38. Because the peripheral linear velocity of the Rollers of the S-roll arrangement 26 is controlled to be less than the peripheral line speed of the rollers of the mechanical stabilization arrangement 38, the shrink-able material 22 is pressed between the S-roll arrangement 26 and the grip space 32 of the incremental stretching rollers 34 and 36 of the mechanical stabilization arrangement 38. By adjusting the difference in the speeds of the rollers, the material capable of narrowing 22 is tensed in such a way that it narrows a desired amount and is maintained in such a tight, tapered condition. The mechanical stabilization arrangement 38 provides a stabilized, non-woven web, which can be bonded to other materials. As the tapered material 22 is tensioned between the S-roll arrangement 26 and the grip space 32 the incremental stretching rolls 34 and 36, the tension is applied to the material capable of narrowing in a direction parallel to the first direction or parallel to the direction of the machine or DM. The tensioning of the tapered material 22 in a direction parallel to the first direction causes the material capable of narrowing narrowing in a direction perpendicular to the first direction or in a direction parallel to the direction DT or transverse direction of the machine. Before entering the gripping space 25 of the roller arrangement at S 26, the narrowing material 22 has a dimension 71 of the surface path length DT or transverse to the machine when it is tensioned between the roller arrangement at S 26. and the gripping space 32 of the incremental stretching rollers 34 and 36 of the mechanical stabilization arrangement 38, the shrinkable material 22 is tapered such that its new dimension Z 'of the surface path length DT is smaller than the Z dimension of the surface path length DT. The dimension Z 'of the surface path length DT is preferably less than about 75% of the dimension Z of the surface path length DT, more preferably less than about 50% of the dimension Z of the surface path length DT, and most preferably less than about 30% of the Z dimension of the surface path length DT. For example, the material 22 having a dimension Z of the surface path length DT of 10 inches, can be narrowed to have a dimension Z 'of the surface path length DT of 5 inches, which is 50% of the Z dimension of the DT path length of 10 inches. The method for determining the surface path length of the frame can be found - in the Test Methods section set forth in later parts of the present description. Other methods of tensioning the narrowing material 22 can be used such as, for example, drawing frames. The narrow-capable material 22 may be of stretch, elastic or non-elastic non-woven material. The shrinkable material 22 may be a spunbonded web, a meltblown web, or a webbed web. If the material capable of tapering is a web of blown fibers in the molten state, this may include blown microfibers in the molten state. The shrinkable material 22 can be made of fiber forming polymers such as, for example, polyolefins. Exemplary polyolefins include one or more of polypropylene, polyethylene, ethylene copolymers, propylene copolymers, and butene copolymers. In one embodiment of the present invention, the shrinkable material 22 may be a multilayer material having, for example, at least one layer of a spunbonded web attached to at least one layer of a blown web in the cast, a carded web by link or other suitable material. Alternatively, the narrowing material 22 can be a simple layer of material such as, for example, a spunbonded web, a meltblown web, or a webbed web. The material capable of shaping 22 may also be a composite material made of a mixture of two or more different fibers or a mixture of fibers and particles. These mixtures can be formed by adding fibers and / or particles to the gas stream in which the meltblown fibers are carried in such a way that intimate mixing of the meltblown fibers and other materials, for example, is entangled. wood pulp, staple fibers, and particles such as, for example, hydrocolloid particles (hydrogel) commonly referred to as superabsorbent materials, occur prior to collecting the meltblown fibers in a collection device to form a coherent web of the blown fibers in the molten state and other randomly dispersed materials. The non-woven web of fibers must be joined together to form a coherent weft structure which is capable of resisting the constriction. Suitable bonding techniques include, but are not limited to, chemical bonding, thermal bonding, such as dot calendering, hydroentanglement, and sewing. Figure 2 is an enlarged perspective illustration of a preferred embodiment of the mechanical stabilization arrangement 38 employing opposing pressure applicators having three-dimensional surfaces which at least to one degree are complementary to one another. The mechanical stabilization arrangement 38 shown in Fig. 2 comprises incremental stretching rollers 34 and 36. The narrowing material 22 passes through the gripping space 32 formed by incremental stretch rollers 34 on the 36 as the rollers incrementally stretch. They rotate in the direction indicated by the arrows associated with them. The higher incremental stretching roller 34 comprises a plurality of corresponding teeth 40 and grooves 41 extending approximately the total circumference of the roller 34. The incremental stretching roller 36 below comprises a plurality of corresponding teeth 42 and grooves 43 which extend to approximately the total circumference of the roller 36. The teeth 40 on the roller 34 mesh internally with or engage the grooves 43 on the roller 36, while the teeth 42 on the roller 36 mesh internally with or engage with the grooves 41 or have roller 34 The teeth 40 and 42 on the rollers 34 and 36, respectively, extend in a direction substantially perpendicular to the direction of travel or first direction of the material capable of narrowing 22 or in a direction substantially parallel to the width of the material capable of narrowing. That is, the teeth 40 and 42 extend in a direction parallel to the direction tr ansverse! of the machine or direction DT. The incremental stretching rollers 34 and 36 will stretch the weft pattern in a direction generally perpendicular to the direction of shrinkage thereby stabilizing the constricted material 22 such that it remains in its narrowed condition after passing through the stretching rollers. Ncremental 34 and 36 and tension is released on the constricted material. By stabilizing the constricted material, the constricted material substantially maintains its narrowed dimension without returning to its precursor dimension. . .. After being stabilized by passing through the incremental stretching rollers 34 and 36, the stabilized constricted material 22 includes a plurality of stabilizing embossments 44. The stabilizing embossments 44 extend in a substantially linear direction parallel to each other through of the total width of the stabilized tapered material 22. The stabilizing bumps 44 are shown to be extending in a direction substantially parallel to the TD or transverse direction of the machine. As shown in FIG. 2, each stabilization enhancement extends through the stabilized tapered material 22 from one edge to the other edge. This is very important since this fixes the fibers across the total width of the weft thus stabilizing the weft. If the stabilizing embossments 44 do not extend fully through the material capable of tapering 22, the portion of the material capable of tapering that is not embossed would return to its broad precursor. For example, a separate pattern of enhancements, as shown in Figure 8, would not set or maintain the material effectively. The portions of material between the individual enhancements would not be maintained, and therefore, would allow the material to return to its precursor dimension. The incremental stretching rollers 34 and 36 can include any number of teeth and grooves to provide the desired stabilization in the nonwoven web. In addition, the teeth and the grooves may be non-linear, such as, for example, curved, sinusoidal, zig-zag, etc. In addition, the teeth and the grooves may extend in a different direction perpendicular to the direction of travel of the weft capable of narrowing. For example, the teeth and the grooves can extend to a null in relation to the direction DT, but preferably not parallel to the DM or direction of the machine, since this type of incremental stretch would tend to expand the width of the frame, in this way canceling the purpose of the operation of the narrowing. After passing through the incremental stretching rollers 34 and 36, the constricted, stabilized material 22 is fed to the apparatus 45. Figure 3 is an enlarged illustration of the apparatus 45. The apparatus 45 provides a treatment popularly known as " micrexing ". An apparatus for providing microload treatment similar to apparatus 45 is produced by the Micrex Corporation of Walpole, Massachusetts. The weft 22 of the constricted extensible material is passed between a peripheral surface 45 of the cylinder 47, which is driven in the rotational movement in a direction indicated by the arrows associated therewith and a device 48 which presses the stretched stretchable material, stabilized 22, against the peripheral surface 46 of the cylinder 47. A delay member 49 retards the passage of the stabilized constricted stretchable material 22. The delay member 49 has a surface 50 which forms an acute angle with the peripheral surface 46 of the cylinder 47 in a direction of rotation of the cylinder. The surface 50 directs the stabilized, stretched extensible material away from the peripheral surface of the cylinder 47. A more detailed description of the micromixing operation and apparatus is described in U.S. Patent No. 3,260,778 issued to Walton on July 12. of 1966; U.S. Patent No. 3,426,405 issued to Walton on February 11, 1969; and U.S. Patent No. 5,117,540 issued to Walton et al. on June 2, 1992. Each of these patents is incorporated herein by reference. Referring now to Figure 1, after the matter! able to narrow 22 passes through the micrexating apparatus 45, this is wound on a tensioning roller 52. The stabilization of the material capable of narrowing in its narrowed condition which allows it to be wound on a tensioner roller while in its narrowed condition and then later used for the desired end use. Once the narrowing material has been mechanically stabilized or maintained, it is suitable for handling in conventional high speed diaper conversion equipment without the need for special handling equipment. The stabilized constricted material is easily extended in a direction parallel to the direction of the constriction. That is, the stabilized constricted material is easily extended or elongated in the transverse direction of the machine or in a direction perpendicular to the first direction. The extension capacity in a direction perpendicular to the first direction is provided by the tightening and stabilizing steps. Additionally, the stabilized constricted material is easily extended in a direction parallel to the first direction. The extension capacity in the first direction is provided by the microuting operation. Accordingly, the stabilized microtable and tapered material is easily extended in two directions, that is, in a direction parallel to the first direction and in a direction perpendicular to the first direction. The stretched, stabilized extensible material is capable of elongation in a direction perpendicular to the first direction by applying a torsional force of at least about 60% without suffering catastrophic failure (ie, a torsional length, stretched, which is at least 160% of its relaxed length not twisted). Preferably, the stabilized, stretched extensible material is capable of elongation in a direction perpendicular to the first direction upon application of a torsion force of at least about 100% without suffering catastrophic failure, (i.e., at a stretched length , twisted which from at least approximately 200% of its relaxed length without twisting). Because the stretched, stabilized stretchable material is extensible and non-elastic, the stabilized stretched, stretchable material does not recover more than 55% of its elongation upon release of the stretching force, elongation, and preferably not more than 25%. % of its elongation when releasing the stretching force, elongation. The stabilized, stretched extensible material is preferably capable of elongating in a direction perpendicular to the first direction at least about 60% and more preferably at least about 100% more if suffering catastrophic failure when applying a relatively high torsional force. low. The stabilized, stretched extensible material is preferably capable of elongation in a direction perpendicular to the first direction to at least about 60% and more preferably to at least about 100% without suffering catastrophic failure upon application of a torsional force. less than about 300 grams, more preferably by applying a torque force of less than about 200 grams, and most preferably by applying a torque force of less than about 100 grams.

The stretched, stabilized extensible material is also capable of elongating in a parallel direction upon the occurrence of the application of a torsional force of at least about 20% without suffering catastrophic failure (i.e., at a stretched, twisted length, which is at least 120% of its relaxed length without twisting). Preferably, the stretched, stabilized stretchable material is capable of elongating in a direction parallel to the first direction during application of a torsional force to at least about 30% without suffering catastrophic failure (i.e., at a stretched, twisted length). , which is at least 130% of its relaxed length, without twisting). The stabilized, stretched extensible material is preferably capable of elongation in a direction parallel to the first direction to at least about 20% and more preferably to at least about 30% or without suffering catastrophic failure upon application of a relatively low torsional force. . The stabilized, stretched extensible material is preferably capable of elongation in a direction parallel to the first direction to at least about 20% and more preferably to at least about 30% or without suffering catastrophic failure upon application of a lesser torsional force. about 100 grams, more preferably from applying a torque force of less than about 200 grams, and most preferably by applying a torque force of less than about 300 grams. Because the stabilized extensible material is capable of elongating in both parallel and perpendicular directions to the first direction without suffering catastrophic failure during the application of low torsional forces, the stabilized, stretched extensible material is particularly well suited for use in absorbent articles. disposable such as diapers, incontinence briefs, feminine hygiene garments, training pants, and the like, since these are capable of being used in parts of the article where the high extension capa in multiple directions can assist in the adjustment of the article to the body. Conventional drive means and other conventional devices which can be used in combination with the apparatus of Figure 1 are well known and, for purposes of clarity, have not been illustrated in the schematic view of Figure 1. Figure 9 is a Plan view of another pattern of enhancements suitable to stabilize the material capable of narrowing. The pattern includes a plurality of linear enhancements 210 extending continuously across the total width of the weft 205 in a direction generally parallel to the transverse direction of the machine. AND! The pattern also includes a plurality of linear embossments 212 extending continuously across the total width of the weft 205 to a corro angle with respect to the transverse direction of the machine and at an angle of the embossments 210. The weft 205 also includes a plurality of linear embossments 214 extend continuously across the total width of the weft 105 at an angle with respect to the transverse direction of the machine and at an angle with respect to the embossments 210 and 212. Embossments 212 and 214 may extend at any angle to each other and with respect to the embossments 210. FIG. 10 is a plan view of another embossing pattern for stabilizing the material capable of tapering. The pattern includes a plurality of linear embossments 222 extending continuously across the total width of the weft 220 at a corrorate angle to the transverse direction of the machine. The frame 220 also includes a plurality of linear embossments 224 extending continuously through the total width of the weft 220 at an angle to the transverse direction of the machine and at an angle to the embossments 222. The embossments 222 and 224 are preferably aligned perpendicular to one another. However, other angles can also be employed between the linear enhancements 222 and 224.

The pattern of enhancement of Figures 9 and 10 is provided by feeding the constricted material through a grip space formed by a pair of pattern compression rolls. Each roller comprises a series of raised surfaces, similar to the teeth 40 and 42 on the rollers 34 and 36, respectively. The raised surfaces on each of the rollers are complementary and couple to one another and compress the narrowed material providing the pattern of enhancements shown in Figures 9 and 10. The compression provided by the pattern compression rollers keeps the individual fibers stabilize the plot in its narrowed condition. Alternatively, the pattern compression rolls may comprise a pattern roll having a pattern of raised surfaces and an anvil roll having a smooth surface. The raised surfaces on the pattern roll compresses the constricted material against the anvil roll to provide the pattern of enhancements shown in Figures 9 and 10. The stretched, stabilized extensible material can subsequently be attached to an elastic member to form a material elastic composite. Preferably, the stabilized stretchable constricted material is joined with an elastic member while the elastic member is in a substantially unstressed condition. Matter! stretchable, stabilized, and elastic member may be attached to each other either intermittently or substantially continuously along at least a portion of their coextensive surfaces, while the elastic member is in, either, a tensioned or unstressed condition The stretched, stabilized extensible material can be attached to an elastic member after it has been removed from a roller, such as the tension roller 50, or can be attached to an elastic member after it has been immediately subjected to the microlocking operation. The elastic member can be made from any suitable elastic material. Generally, any of the resins that form suitable elastomeric fibers or mixtures containing the same, can be used for the non-woven webs of elastomeric fibers and any of the resins that form elastomeric film or mixtures containing the same can be used for the films elastomeric of the invention. For example, the elastic member may be an elastomeric film made from block copolymer having the general formula ABA 'wherein A and A' are each a thermoplastic polymer end block containing a styrenic portion such as poly (vinyl) arene) and where B is the middle part of the block of the elastomeric polymer such as a conjugated diene or a lower alkene polymer. Other elastomeric films are exemplary that can be used to form the elastic sheet include elastomeric polyurethane materials such as, for example, those available under the trademark TIN from B.F. Goodrich & Company, polyamide elastomeric materials such as, for example, those available under the * PEBAX trademark of Rilsan Company, and polyester elastomeric materials such as, for example, those available under the trade designation Hytrel of E.l. DuPont De Nemours & Company A polyolefin can also be mixed with the elastomeric polymer to improve the processability of the composition. The polyolefin must be one that; when mixed and subjected to an appropriate combination of high pressure and high temperature conditions, it is extrudable, in the mixed form, with the elastomeric polymer. Useful blend polyolefin materials include, for example, polyethylene, polypropylene and polybutene, including ethylene copolymers, polypropylene copolymers, and butene copolymers. The elastic member may also be a sheet of elastomeric pressure sensitive adhesive. For example, the elastic material itself can be tacky or, alternatively, a compatible tackifying modifier resin can be added to the extrudable elastomeric compositions described above to provide an elastomeric sheet that can act as a pressure sensitive adhesive, for example, to join the elastomeric sheet to a non-elastic, tapered, stretched web. The elastic sheet may also be a multilayer material which may include two or more individual coherent plies or films. Additionally, the elastomeric sheet can include a multilayer material in which one or more of the layers contain a mixture of elastic and non-elastic fibers or particles. Other elastomeric materials suitable for use as the elastic member include "living" synthetic or natural rubber including thermo shrinkable elastomeric films, elastomeric formed canvases, elastomeric foams, or the like. In an especially preferred embodiment, the elastic member comprises an elastomeric canvas available from Conwed Plastics. The ratio between the original dimensions of the material capable of tapering 22 to its dimensions after tensioning or narrowing determines the approximate limits of stretching of the composite elastic material. Because the material capable of being stretched is capable of stretching and returning to its narrowed dimension in directions such as, for example, the machine direction or the transverse direction of the machine, the composite elastic material will be able to stretch in generally the same direction as the material capable of narrowing 22. For example, with reference to Figures 4, 5 and 6, if it is desired to prepare a composite elastic material capable of stretching to an elongation of 150% in multiple directions (ie both parallel as perpendicular to the first direction), a width of the material capable of narrowing shown schematically and not necessarily to scale in Figure 4 having an "X" width such as, for example, 250 cm, is tensioned in such a way that to a "Y" width of approximately 100 cm. The tapered nonwoven web shown in Figure 5 is mechanically stabilized to provide a stretchable, stabilized tapered material. The material is now capable of elongating in a direction parallel to the direction of the constriction, that is, in a direction perpendicular to the first direction during the application of relatively low forces. The stabilized, stretched extensible material is then micrilled to provide a material that is capable of elongation in a direction perpendicular to the direction of the constriction, ie, in a direction parallel to the first direction, upon application of relatively low forces. The stabilized, stretched extensible material is then bonded to a 100 cm square elastic member which is at least capable of stretching to a dimension of 250 cm x 250 cm. The resulting composite elastic material shown schematically and not necessarily to scale in Figure 6 has a "Y" width of approximately 100 cm and is capable of stretching in a direction perpendicular to the first direction to at least the original "X" width of 250 cm of the material capable of narrowing for an elongation of approximately 150%. The material is also capable of stretching in a direction parallel to the first direction to at least the original 250 cm length of the material capable of narrowing for an elongation of approximately 150%. As can be seen from this example, the elastic limit of the elastic member needs only to be as large as the desired minimum elastic limit of! Composite elastic material. Referring now to Figure 7, there is schematically illustrated another process 100 for forming a narrowing material of the present invention. A material capable of tightening 122 is unwound from a supply roll 123 and travels in the direction indicated by the arrows associated therewith as the supply roll 123 rotates in the direction indicated by the arrows associated therewith. The narrow-capable material 122 passes through the gripping space 125 of the S-roll arrangement 126 formed by the multiple rollers 128 and 130. The narrow-able material 122 can be formed by known non-woven extrusion processes., such as, for example, known meltblown processes or known spunbond processes, and passed directly through the gripping space 125 without first being stored on a supply roll. From the pattern-increasing arrangement in the transverse direction of the machine 107, the non-woven fabric capable of tapering 102 passes through the gripping space 125 of the S-roll arrangement 126 formed by the multiple rollers 128 and 130 .

The narrowing material 122 passes through the gripping space 125 of the S-roll arrangement 126 in an inverse S-path as indicated by the rotation direction arrows associated with the multiple rolls 128 and 130. of the roll arrangement at S 126, the narrowing material 122 passes through the gripping space 145 formed by the pressure roller arrangement 140 composed of the pressure rollers 142 and 144. Because the peripheral linear speed of the Roller arrangement rollers at S 126 is controlled to be less than the peripheral line speed of the rollers of the pressure roller arrangement 140, the narrow capable material 122 is tensioned between the roller arrangement at S 126 and the gripping space of the arrangement of the pressure roller 140. By adjusting the difference in the speeds of the rollers, the material capable of tightening 122 is tensioned in such a way that it narrows a desired amount and is maintained nest in such a tense, narrowed condition. From the arrangement of the pressure roller 140 the narrowing material 122 passes through the gripping space 151 formed by the mechanical stabilization arrangement 152 composed of the incremental drawing rollers 153 and 154. Because the linear speed is controlled peripheral of the roller of the pressure roller arrangement 140 to be less than or equal to the peripheral linear speed of the rollers of the mechanical stabilization arrangement 152, the material is maintained in its tensioned and / or tapered condition between the roller arrangement of pressure 140 and the mechanical stabilization arrangement 152. From the mechanical stabilization arrangement 152 the material capable of being narrowed is fed to the micrexating apparatus 160. The micrincing apparatus includes the cylinder 162, a device 164 for pressing the material 122 against the surface of the cylinder 162 and a delay member 166, which retards the passage of the material 122 and then directs the mat away from the peripheral surface of the cylinder. After leaving the micrexating apparatus 160, the stabilized constricted material 122 is wound on a tension roller 170. Conventional driving means and other conventional devices which can be used in combination with the apparatus of FIG. 7 are well known and, for purposes of clarity, they have not been illustrated in the schematic view of Figure 7.

Test Methods The measurements of the surface path length of the non-woven web will be determined by analyzing the non-woven webs by means of microscopic image analysis methods. The sample to be measured is cut and separated from the nonwoven web. A tensionless sample length of 1.25 cm will be "measurement mark" perpendicular to the "measured edge", while it is attached to the weft, and then cut out exactly and removed from the weft. The measurement samples are then mounted on the long edge of a microscope glass slide. The "measured edge" will be slightly extended (approximately 1 mm) out from the edge of the slide. A thin layer of pressure sensitive adhesive is applied to the edge facing the glass to provide a suitable sample support means. For a sample that has deep roughness, it may be necessary to gently extend the sample (without imposing significant force) to facilitate contact and fixation of the sample to the edge of the slide. This allows the identification of the improved edge during the image analysis and avoids the possible edge portions with "wrinkle" that requires additional interpretation analysis. The images of each sample are to be obtained as views of the "measured edge" taken with the "edge edge" of the support slide using suitable microscopic measuring means of sufficient quality and amplification. The data is obtained using the following equipment: Video unit Keyence VH-6100 (20X lens), with video image impressions made with a Sony Video Mavigraph printer unit. Video impressions are scanned images with a Hewlett Packard ScanJet IIP scanner. The image analysis is on a Macintosh HCi computer that uses the NIH MAC image software version 1.45. Using this equipment, a calibration image initially taken from a grid scale length of 0.500"with increment marks of 0.005" will be used for setting the calibration of the computer image analysis program. All the samples that are measured are then video images and video image impressions. Next, all video impressions are images scanned at 100 dpi (256 level on the gray scale) in a suitable Mac image file format. Finally, each image file (including the calibration file) is analyzed using the Mac Image 1.45 computer program. All samples are measured with the selected hands-free line measurement tool. The samples are measured on both lateral edges and the lengths are recorded. Thin samples only require a lateral edge to be measured. Thick samples are measured on both lateral edges. The traces of length measurement are going to be made along the total measured length of a cut sample. In some cases multiple images (partially overlapping) may be required to cover the total cut sample. In these cases, select the common characteristic aspects for both overlap images and use them as "marks" to allow the readings of the image length to join but not overlap. The final determination of the surface path length is obtained by averaging the lengths of five (5) measured samples of Vz separated from each region. Each "surface path length" of the measured sample is to be the average of both surface path lengths of the lateral edge. Although the test method described above is useful for many of the frames of the present invention, it is recognized that the test method has to be modified to accommodate some frames. Although certain particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, it is intended to protect in the appended claims all changes and modifications that are within the scope of the present invention. "" '

Claims (10)

1. A method of producing a stabilized, stretched extensible material, characterized by the steps of: providing a material capable of shaking; feed the material capable of narrowing in a first direction; applying a tension force to the material capable of tapering to constrict the material in a direction perpendicular to the first direction; subjecting the material capable of narrowing to mechanical stabilization to provide a material capable of stretching, stabilized; passing the stretch-able material, stabilized between a peripheral surface of a cylinder, which is driven in rotary motion and a device for pressing the stretchable, stabilizing, stabilized material against the peripheral surface of the cylinder; retarding the passage of extensible stabilized material, stabilized, by a delay member; and direct the material capable of stretching, stabilized, far from the peripheral surface of the cylinder.

2. The method according to claim 1, wherein step d) comprises subjecting the constricted material to incremental stretching.

3. The method according to claim 2, wherein the incremental stretching comprises feeding the constricted material through a gripping space formed by a pair of incremental stretching rollers.

The method according to claim 3, wherein each incremental stretching roller comprises a plurality of teeth and a plurality of grooves.

5. The method according to claim 1, wherein the mechanical stabilization comprises feeding the constricted material through a grip space formed by a pair of patterned compression rolls.

The method according to claim 5, wherein the standard compression rolls provide continuous stabilizing compression enhancement throughout the entire material.

The method according to any one of the preceding claims, wherein the material capable of tapering is a web selected from the group consisting of a web of webbed fibers, a web of spunbonded fibers, a web of blown fibers molten state, and a multi-layered material that includes at least one of said frames.

8. The method according to claim 1, further comprising the additional step of: (f) attaching the stabilized, stretched extensible material to an elastic member. The method according to claim 1, wherein the stabilized, stretched extensible material is directed away from the peripheral surface of the cylinder by the delay member. The method according to claim 9, wherein said delay member has a surface that forms an acute angle with the peripheral surface of the cylinder in the direction of rotation of the cylinder.