JPH0737703B2 - Nonwoven elastic web with gears - Google Patents

Description

Description: FIELD OF THE INVENTION The field of the invention includes composite non-woven elastic webs including non-woven elastic webs bonded to non-woven gathered webs and methods of forming such composite non-woven elastic webs. . The field of the invention also includes methods of forming elastic gathered nonwoven elastic webs by gathering by shrinking the nonwoven elastic web and then separating the gathered web from the nonwoven elastic web.

Background of the Invention Diapers and sanitary napkins (hereinafter simply referred to as napkins)
In the field of manufacturing, it is considered desirable to provide an outer cover on the napkin. Such outer covers are
(1) Elasticity over the entire surface (tight but comfortable wearing feeling), (2) Water repellency (holding fluid inside the napkin), (3) Breathability (of vapor through the napkin material) It is desirable that they can be replaced), (4) be soft (improve the feeling of wearing), and (5) be inexpensive.

Unfortunately, known composite non-woven materials currently on the market lack one or more of the above properties. further,
These composite elastic nonwoven materials have not been formed utilizing the novel and economical methods of this invention.

For example, the method of making a composite elastic sheet material disclosed in Wade, U.S. Pat. No. 2,957,512, joins a crepe or wrinkled flexible sheet material to, for example, an elastic meltblown material. Col. 5, page 39-48 of this U.S. Patent, a fibrous web of elastomeric material may be stretched and joined to a wrinkled web at spaced points or regions to relax the fibrous elastomeric web. It is described that the composite has a structure shown in FIG.

Another method of forming a composite elastic fabric is Pufahl's U.S. Pat.
No. 316,136. A preferred method of making this fabric utilizes an adhesive which is first applied to the elastic backing in a predetermined pattern and then stretched. While the elastic backing is in the stretched state, the overlay is placed on it and the overlay is pressed into engagement with the elastic backing for a time sufficient to ensure the two layers are adhered together. Then, after the applied adhesive dries, the tension applied to the elastic backing material is released, and the top cloth is gathered in the area drawn with the adhesive.

Example 56 of Evans U.S. Pat. No. 3,485,706 discloses making unidirectional elastic stretchable non-woven multi-ply patterned structures from an initial layered material. This construction consists of two polyester staple fiber webs with a spandex yarn web in between.
The webs are bonded together by utilizing jet water to entangle the fibers of one web with the fibers of an adjacent web. During the entanglement stage, the spandex yarn stretches by 200 percent.

Brown, U.S. Pat. No. 3,673,026, discloses a method of making a laminated fabric, and in particular, a method of making a non-woven laminated fabric with controlled bulk. In this way, non-woven materials such as
Separate webs of crepe tissue or bonded synthetic fibers are elastically stretched at different elongations and bonded and laminated together in these different stretched states. The bonded webs are then relaxed causing each web to contract to varying degrees, and then the webs are separated at the non-bonded areas to control the bulk of the laminate. In this U.S. patent, various stretchings include the practice of actually stretching only one web and maintaining the other web in a relaxed or near-near state.

Wideman, U.S. Pat. No. 3,687,797, discloses a method of making a resilient cellulosic cotton product obtained by laminating a low cellulosic cotton web to a pre-expanded polyurethane foam web. In this method, either web is coated with the adhesive in the desired pattern, and then the batting web is laminated to the pre-stretched polyurethane foam web. During this lamination step, the polyurethane foam web is maintained in tension. After laminating the two webs, the tension on the pre-stretched polyurethane foam web is released, causing shrinkage of the foam web.
The adhesive holds the wadding product and foam together and provides bulk in the areas between the bonded areas. The stress remaining in the product after shrinkage can be further relieved by wetting.

Wideman U.S. Pat. No. 3,842,832 is directed to disposable stretchable products such as bandages and methods of making the same. This product is manufactured by applying an adhesive on one side through a longitudinally stretched nonwoven material over a roller. At the same time, the polyurethane web is heated and longitudinally stretched before being bonded to the nonwoven material.
The second nonwoven material is then adhered to the other side of the polyurethane web to form a laminate of an inner stretched polyurethane core and an outer non-stretched nonwoven layer adhesively adhered to the core. Next, this laminated body is passed through a humidifier,
Relaxation is provided in the engagement between the nonwoven outer layer and the adhesive bonding the stretched polyurethane core layer thereto. This allows the stretched polyurethane layer to return to approximately its original length, causing the outer nonwoven layer to shrink or wrinkle and wrinkle.

Nedza U.S. Pat. No. 4,104,170 discloses a liquid filter having an improved stretch polypropylene element. The manufacture of polypropylene elements is accomplished by forming a nonwoven sublayer of continuous polypropylene fibers that are laminated and adhered in a random pattern. The upper layer of short polypropylene fibers is then attached to the lower layer, for example by melt-blasting the upper layer onto the lower stretched sheet.

A method of making an elastic fabric structure comprising fibers of a relatively elastic synthetic organic polymer and fibers of a relatively inelastic synthetic organic extensible polymer is disclosed in Sisson U.S. Pat. No. 4,209,563. This method is carried out in a state in which relatively elastic fibers and stretchable but relatively inelastic fibers are sufficiently dispersed and installed on the porous forming surface of the nonwoven web having random fiber intersections. Includes. Thereafter, at least some of the fiber intersections are bonded to form a cohesive adhesive fabric, which is stretched to stretch some of the fibers in at least one direction and then loosened to form a web of relatively elastic fibers. Performs bunching, forming a relatively inelastic fiber loop that can be expanded by contraction. Advancement of the fiber relative to the porosity forming surface is positively controlled and this positive control is contrasted with the use of airflow to convey the fiber at column 7, lines 19-33 of this US patent. Also, at column 9, line 44 et seq. Of this U.S. Patent, it is stated that embossing patterns and low head nip with smooth heads can be used to bond filaments to form a cohesive cloth.

U.S. Pat. No. 4,296,163 to Emi et al. (A) is a mesh structure composed of fibers of a synthetic elastomeric polymer, wherein the individual fibers are randomly interconnected in an irregular relationship and have a number of different sizes and shapes. A sheet-like mesh structure having a recovery rate after 10% elongation of at least 70% in two randomly chosen directions that are perpendicular to each other on its plane, (B ) A cohesive assembly with a matte, web or sheet fibrous structure of short or long fibers having a 10% elongation recovery of less than 50% in at least one randomly selected direction. A fibrous composite material having the same is disclosed. The U.S. patent states that the elastic composite material is suitable as an industrial material such as various apparel base materials, filter cloths, absorbent materials, and heat insulating materials.
The method of forming this composite is described at column 6, line 64 and beyond, which involves binderless bonding as described at column 9, lines 15-41.

Des Marais U.S. Pat. No. 4,323,534 discloses a method of extruding a thermoplastic composition for fibers having exceptional strength and good elasticity. In column 8 of this US patent, under the subtitle "Fiber-Forming", 79.13%
KRATON G-1652 with 19.78% stearic acid, 0.98
A meltblown operation of a compounded resin containing 0.1% titanium dioxide and 0.1% Irganox 1010 antioxidant is disclosed. It is also described that individual fibers were extruded from a meltblown mold.

Jones U.S. Pat. No. 4,355,452 discloses a panty with a built-in elastic system that minimizes gathers and provides a comfortable wearing feel, and a method of assembling the panty. It states that a material made of meltblown KRATON rubber is well suited for panty cloth material. Also disclosed is a method of making a meltblown KRATON fabric, shown schematically in Figure 8 of this U.S. Patent. Methods which appear to utilize KRATON G-1652 are discussed at column 4, line 67 et seq. Of this U.S. patent.

Wahlquist U.S. Pat. A small diameter discontinuous fiber is directly melt-blown in a mat shape on the adhesive web. Column 3 of this U.S. Patent, No. 35-
By forming the ultrafine fiber mat directly on the pre-bonded continuous filament web in the 40th row, a main bonding portion is generated between the ultrafine fiber and the continuous filament, and the ultrafine fiber mat is formed into a continuous filament. It is said to be attached to the web.

Likhyani U.S. Pat. No. 4,426,420 heat treats a hydraulically entangled spunlace fabric consisting of at least two types of staple fiber and an elastomeric fiber that behaves as a normal staple fiber until heat treated to provide the fabric with improved extensibility and elasticity. The method of giving is disclosed. The method involves drawing a fiber of the latent elastomer and relaxing it between the drawing and winding steps.

Romanek U.S. Pat. No. 4,446,189 includes at least one layer of non-woven textile fabric attached to the elastic layer by needle punching, wherein the non-woven textile fabric layer is permanently stretched when the elastic device is stretched within its elastic limits. Disclosed is a non-woven textile fabric laminate. When the elastic layer is relaxed and returned to its substantially unstretched state, the nonwoven fabric layer is simultaneously relaxed, thereby increasing the bulkiness. Further, it is described that the non-woven textile fabric laminate can be used to make a garment with increased freedom of movement.

The abstract of Japanese Document No. 47-43150 uniaxially stretches a sheet or film made of a mixture of (a) incompatible polymers, (b) superimposes this sheet or film with a layer of foamed polymer, ( Disclosed is a method for producing a highly tacky non-woven fabric by c) stretching the laminate at right angles to the stretching direction of the base layer, and (d) stretching in the stretching direction of the base layer. Preferred polymers are described as polyamides, linear polyesters and polyolefins. Preferably, the upper layer is polypropylene foam.

Shell Chemical C entitled "KRATON Thermoplastic Rubber"
The ompany booklet describes the thermoplastic KRATON material. This booklet is "SC: 198-83 printed in USA7 /
The code is "83 SM".

Although the various publications above may disclose products and methods having some of the features or method steps of the present invention, those methods provide the methods or products claimed herein. Is not disclosed or suggested.

Definitions The terms "elastic" and "elastomer" are capable of stretching to a stretch bias length of at least 125 percent (which is about 1 1/4 of the relaxed unbiased length) when a bias force is applied. Is used interchangeably to mean any material that recovers at least about 40 percent of its elongation when unraveled. A hypothetical example that would satisfy this definition for an elastomeric material is that it could extend to at least 1.25 inches and
There is a 1 inch material sample that recovers to a length of 1.15 inches or less when stretched to an inch and then relaxed. Many elastic materials are capable of stretching well above 25 percent of their relaxed length, and many will recover to about their original relaxed length when the stretching force is relaxed. This latter class of materials is generally preferred for the purposes of the present invention.

The term "recovery" as used herein means the contraction of a material when a bias force is applied to stretch the material and then the bias force is removed. For example, if a material having a relaxed non-biased length of 1 inch is stretched 50 percent by stretching to a length of 1.5 inches, the material will have a stretched length of 150 percent of its relaxed length. After removing the bias stretching force, this stretched material is 1.
When contracted, or recovered, to a length of 1 inch, the material has recovered 80 percent (0.4 inch) of its elongation.

As used herein, the terms "non-elastic" or "non-elastomeric" refer to "elastic" or "elastomer".
Means a material not included in the term.

As used herein, the term "meltblown ultrafine fibers" means an average diameter of no more than about 100 microns, preferably about
A small diameter fiber having an average diameter of from 0.5 microns to about 50 microns, more preferably from about 4 microns to about 40 microns, wherein molten thermoplastic material is passed through a plurality of fine, normally circular die capillaries to produce a high velocity gas (eg, air)
It refers to small diameter fibers made by extruding into a stream in the form of molten filaments or filaments and thinning the filaments of molten thermoplastic material by this high velocity gas stream to reduce the diameter to the above range. After this, the high velocity gas stream carries the meltblown ultrafine fibers to a collection surface where they adhere and form a randomly distributed web of meltblown ultrafine fibers. This process is described, for example, in the Butin U.S. Pat.
No. 3,849,241, the disclosure of which is incorporated herein by reference.

As used herein, the term "binderless bonded microfibrils" has a diameter not exceeding about 100 microns, preferably about 10 microns.
Small diameter fibers having a diameter of from micron to about 50 microns, more preferably from about 12 microns to about 30 microns, extruding a molten thermoplastic material into filaments through a plurality of thin, usually circular capillaries of a spinneret. ,
It refers to small diameter fibers made by rapidly reducing the diameter of extruded filaments, such as by draw drawing and other well known binderless bonding mechanisms. The production of bonded non-woven webs is Ap
No. 4,340,563 to pel, the disclosure of which is also incorporated herein by reference.

The term "nonwoven web" as used herein includes a web of any material formed without the use of a textile weaving process that provides a structure made of individual fibers interwoven in a identifiable and repeatable manner. . Specific examples of nonwoven webs include, but are not limited to, meltblown nonwoven webs, binderless bonded nonwoven webs, porous films,
There are microporous webs and staple fiber card webs. These nonwoven webs have an average basis weight of less than or equal to about 300 grams per square meter. Preferably, the nonwoven web has an average basis weight of about 5 grams to about 100 grams per square meter. More preferably, the nonwoven web has an average basis weight of about 10 grams to about 75 grams per square meter.

The expression “consisting essentially of” as used herein does not exclude the presence of additional materials that have a negligible effect on the elastomeric and other properties of a given composition. Such substances include pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, solid solvents, particles, substances added to enhance the processability of the composition.

As used herein, the term "styrene component" refers to Means a monomer unit represented by.

Unless otherwise defined or limited, the term "polymer" or "polymer resin" as used herein is not meant to be limiting in a broad sense, but a homopolymer,
Copolymers (eg, block, graft, random,
Alternating copolymers, terpolymers, etc.) and their blends and modifications. Further, unless otherwise specified, "polymer",
The term "polymeric resin" will include all possible geometrical molecular shapes of the material. These molecular shapes include, but are not limited to, isotactic, syndiotactic, random symmetries.

OBJECT OF THE INVENTION The general object of the present invention is to provide a new method of forming a composite nonwoven elastic web comprising a nonwoven elastic web and a fibrous nonwoven gathered web bonded thereto.

Another object of the present invention is a composite non-woven elastic web comprising a non-woven elastic web bonded to a fibrous non-woven gathered web, wherein the surface of the non-woven elastic web is directly fibrous in a gatherable state. A fibrous non-woven gathered web is gathered as a result of forming the non-woven gathered web and a non-woven elastic web is formed into a composite non-woven elastic web that is maintained in a stretch bias condition, and then the non-woven elastic web is formed. It is an object of the present invention to provide a novel method of relaxing a web from its stretch-biased state or length to a relaxed non-biased state or length.

Yet another object of the present invention includes a nonwoven elastic web bonded to a fibrous non-woven gathered web, the fibrous non-woven gathered web formed on the surface of the non-woven elastic web in a gatherable condition. At the same time providing a composite nonwoven elastic web bonded thereto.

Yet another object of the present invention is to provide a composite nonwoven elastic web formed by the method of the present invention.

Another object of the present invention is to provide a novel method of forming a gathered nonwoven web that is elastic only from non-elastic materials.

Yet another object of the present invention is a novel method of forming a gathered nonwoven elastic web that forms a nonwoven gatherable web directly on the surface of the nonwoven elastic web and stretch biases the nonwoven elastic web. Releasably connecting the gatherable web to the non-woven elastic web and then relaxing the non-woven elastic web from its stretched, biased or length to its relaxed, non-biased, or length. It is to provide a method that includes the steps of gathering a gatherable web and separating the gathered web from the elastic web to form an elastic gathered web.

Yet another object of the present invention is a novel method of forming a gathered non-woven elastic web for forming a gatherable web directly on a stretchable porous forming surface and stretching the forming surface. Keep the stretchable web separably bonded to the forming surface, shrink the forming surface to gather the gatherable web, and then separate the gathering web from the forming surface. Forming an elastic gathered web.

Yet another object of the present invention is to provide elastic gathered nonwoven elastic webs formed by the method of the present invention.

Further objects and broad scope of application of the invention will be apparent to those skilled in the art from the details set forth below. However, it should be understood by those skilled in the art that the detailed description of the presently preferred embodiments of the present invention is for illustrative purposes only, and that various changes and modifications may be made from the following detailed description within the spirit and scope of the invention. Would be obvious.

SUMMARY OF THE INVENTION The present invention is directed to a method of making a composite nonwoven elastic web comprising a nonwoven elastic web bonded to a fibrous nonwoven gathered web. In particular, the method of the present invention comprises a gathered non-woven fibrous web bonded to a non-woven elastic web in a relaxed, non-extended state wherein the non-woven elastic web relaxes from a stretch bias length to a relaxed non-biased non-stretch length. A fibrous nonwoven gathered web is then gathered to produce a composite nonwoven elastic web. An important feature of the method of the present invention is that the fibrous non-woven gatherable web is formed directly on the surface of the non-woven elastic web while the non-woven elastic web is maintained in a stretched bias condition.

The nonwoven elastic web can be formed, for example, by the meltblown method or any other method of forming a nonwoven elastic web. For example, the nonwoven elastic web may be a porous web of elastic film different from the meltblown fibrous nonwoven elastic web. The nonwoven elastic web thus formed has a conventional relaxed, non-stretched, non-biased length. The nonwoven elastic web is then stretched by stretching to the stretch bias length.

In the next step of the process, the fibrous non-woven gatherable web is woven, for example, either by a melt blown process or a binderless bonding process, or while maintaining the non-woven elastic web at its stretch bias length. It can be formed by any other method of forming a fibrous nonwoven gatherable web directly on the surface of a woven elastic web. During formation of the fibrous nonwoven gathered with possible web, the nonwoven elastic web at least 125 percent, that is maintained at least about extension length of 1 _^1/4 of the non-bias length and relaxation of the nonwoven elastomeric web. For example, the stretch-bias length of the nonwoven elastic web is maintained in a range of at least about 125 percent of the relaxed non-biased length of the nonwoven elastic web to about 700 percent or more of the relaxed-biased length of the nonwoven elastic web. Get

While the fibrous nonwoven gatherable web is bonded to the nonwoven elastic web, the nonwoven elastic web is maintained at an extended stretch bias length. This results in the formation of a composite nonwoven elastic web that includes a nonwoven elastic web bonded to a fibrous nonwoven gatherable web. Because the fibrous nonwoven gatherable web is formed directly on the surface of the nonwoven elastic web while the nonwoven elastic web is maintained at its extended bias length, at this stage of the method the nonwoven elastic web is Is in an extended stretch bias and the fibrous nonwoven gatherable web is gathered but not gathered.

In one embodiment of the invention, the bonding of the fibrous non-woven gatherable web to the non-woven elastic web is accomplished by thermal bonding which fuses the two webs together. Thermal bonding is from about 50 ° C. below the melting temperature of at least one material utilized to form at least one web to about the melting temperature of at least one material utilized to form at least one web. It can be carried out within a temperature range. At high process rates, thermal bonding can be performed above the melting temperature of one or more materials utilized to form the web. Also, thermal bonding may be performed under appropriate normal pressure conditions. If desired, conventional sonic bonding techniques can be used instead of thermal bonding.

In another embodiment of the present invention, the bonding of the fibrous non-woven gatherable web to the stretched non-woven elastic web during formation of the fibrous non-woven gatherable web on the surface of the elastic web. It is achieved only by interlocking the individual fibers of the gatherable web with the nonwoven elastic web. When the non-woven elastic web is a fibrous non-woven elastic web formed, for example, by meltblown, the entanglement of the fibrous non-woven gatherable web with the fibrous non-woven elastic web is Achieved by entanglement of the individual fibrous elastic webs of the attachable web with the individual fibers of the web. When the nonwoven elastic web is a porous film, the bonding of the fibrous nonwoven web to the film is accomplished by the entanglement of the individual fibers of the fibrous gatherable web into the holes of the film.

In yet another embodiment, the joining of the two webs together is also accomplished by making the nonwoven elastic web from a tacky elastic material.

In any of the method embodiments of the present invention, the bonding of the two webs to each other can be further enhanced by applying pressure to the two webs after forming the gatherable web on the surface of the elastic web. Also, in either embodiment, the bonding of the two webs can be further improved by applying an adhesive to the upper surface of the nonwoven elastic web prior to forming the fibrous nonwoven gatherable web.

After the two webs have been bonded together to form the composite elastic web, the composite nonwoven web is subjected to a biasing force to allow the composite elastic web to relax to its normal relaxed, non-biased length. Because the fibrous nonwoven gatherable web is bonded to the nonwoven elastic web while the nonwoven elastic web is stretched, the relaxation of the composite nonwoven elastic web causes the nonwoven elastic web to contract and gather. Is attached to.

After the non-woven elastic web is gathered by reducing the biasing force applied to the non-woven composite elastic web, the non-woven composite elastic web can be rolled into a roll for storage and shipping. The composite nonwoven elastic web can then be utilized to form a wide range of products, such as outer covers for diapers.

Alternatively, the gathered nonwoven web may be separated from the nonwoven elastic web after gathering by contraction of the nonwoven elastic web. In this embodiment, the gathered nonwoven web, alone, can be utilized with various other webs or film materials to form various products. Interestingly, the discrete gathered nonwoven web retains a considerable degree of gathered morphology and is elastic. The gathered nonwoven web may be formed such that the nonwoven elastic web can be gathered directly onto its surface while being stretched, as described above.

During formation of the nonwoven elastic web on the surface, the fibrous nonwoven gatherable web is separably bonded to the nonwoven elastic web while maintaining the nonwoven elastic web at its extended stretch bias length. As a result, a composite non-woven elastic web is formed that includes the non-woven elastic web and a fibrous non-woven gatherable web releasably bonded to the non-woven elastic web. At this stage of the method, the nonwoven elastic web is stretched to form the fibrous nonwoven gatherable web directly on the surface of the nonwoven elastic web while maintaining the nonwoven elastic web at its stretched bias length. The woven condition is biased and the fibrous nonwoven gatherable web is not gathered but is gatherable.

Fibrous Nonwoven Gatherable Web Separable Bonding to Stretched Nonwoven Elastic Web Allows Fibrous Nonwoven Gatherable to Surface of Nonwoven Elastic Web This is done by intertwining the individual fibers of the web with the nonwoven elastic web. The separable bond of the fibrous non-woven gatherable web to the fibrous non-woven elastic web, where the non-woven elastic web is a fibrous non-woven elastic web formed, for example, by meltblown, is fibrous gatherable This is done by interlocking individual fibers of the web with individual fibers of the fibrous non-woven elastic web. When the nonwoven elastic web is a porous film, the separable bonding of the fibrous nonwoven web to the nonwoven elastic web is accomplished by interlocking the individual fibers of the fibrous gatherable web with the pores of the porous film. Done.

After the separable bond of the two webs to each other to form a composite elastic web, a biasing force is removed from the composite nonwoven elastic web, causing the composite nonwoven elastic web to contract to its normal contracted, non-biased length. .. The fibrous nonwoven gatherable web is separably bonded to the nonwoven elastic web while the nonwoven elastic web is in the stretched state so that when the composite nonwoven elastic web contracts, the gatherable web becomes nonwoven. The shrinkage of the elastic web will cause gathers on its surface.

After gathering the fibrous nonwoven gatherable web by reducing the biasing force on the composite nonwoven elastic web, the gathered fibrous nonwoven web is separated from the nonwoven elastic web, The gathered web is wound into a roll for storage, for example. After separation of the fibrous nonwoven gathered web from the nonwoven elastic web, the nonwoven elastic web can be reused as a forming surface.

Upon separation from the non-woven elastic web, the fibrous non-woven gathered web remains in a gathered form, and when a stretch biasing force is applied in the gathered direction of the fibrous non-woven gatherable web, the gathered web becomes Grow to the extent permitted by the gathers. Importantly, when the stretch bias force is removed, the stretched fibrous nonwoven gathered web is substantially gathered in shape, contracting to length, which is the shape it will have after separation from the composite nonwoven elastic web. . That is, the fibrous nonwoven gathered web has elasticity. The fact that the gathered web retains the gathered morphology upon separation from the nonwoven elastic web is surprising. However, it is more surprising that the separated fibrous nonwoven gathered web has elasticity such that it recovers to at least about 40 percent of its elongation when stretched to its stretch length. That is, the separated fibrous nonwoven web has elasticity or elastomeric properties as defined herein. In fact, it has been found that the fibrous nonwoven gathered web is elastic even when it is made of a non-elastic material such as polypropylene.

Preferably, the fibrous nonwoven gatherable web comprises at least one meltblown fibrous nonwoven web. Other methods available for forming the fibrous nonwoven gatherable web include binderless bonding or any other method that can form the fibrous nonwoven gatherable web. The gathered fibrous nonwoven web may be formed entirely of one type of inelastic material or a blend of two or more inelastic materials. However, gathered non-woven webs have one or more types of inelastic materials and
A blend of one or more elastic materials or 1
It may be made of one or more types of elastic material.
Non-elastic materials forming the fibrous nonwoven gatherable web include non-elastic polyester materials, non-elastic polyolefin materials or one or more non-elastic polyester materials and one or more non-elastic polyolefin materials. There is a blend of. An example of a non-elastic polyester material is polyethylene terephthalate. An example of a non-elastic polyolefin is non-elastic polypropylene sold under the trade name PF301.

Alternatively, the nonwoven elastic web may be eliminated by forming the gathered nonwoven web in a gatherable condition directly on a stretchable surface, eg, a stretchable mesh screen.

In one particular embodiment of the method of the present invention, the tacky fibrous nonwoven elastic web is, for example, a tacky elastic material, such as an ABA 'block copolymer or such A.
Formed by meltblown ultrafine fibers of a blend of -BA 'block copolymer and poly (alpha-methylstyrene). Where A and A'are the end blocks of thermoplastic polystyrene, a polystyrene homolog, and B is the elastic polyisoprene midblock. In some embodiments, A may be an end block of the same thermoplastic polystyrene or polystyrene homolog as A '. The cohesive fibrous non-woven elastic web is then stretched to an extended stretch length, and the fibrous non-woven gatherable web is, for example, the cohesive fibrous non-woven elastic web while maintaining the stretch length. It is formed by meltblown or binderless bonding a fibrous nonwoven gatherable web directly to the surface of the web. As a result of the fact that the fibrous nonwoven elastic web is tacky, the fibrous nonwoven gatherable web is formed on the surface of the tacky fibrous nonwoven elastic web while being adhered thereto. In this example, a composite non-woven elastic web is formed having a non-gathered fibrous non-woven gatherable web adhered to a cohesive fibrous non-woven elastic web, the bonding of the two webs to each other being the fibrous non-woven. This is done by the adhesion that occurs during the formation of the fibrous nonwoven gatherable web to the surface of the elastic web.
Adhesion of the two webs to each other can be enhanced by applying pressure to the composite nonwoven elastic web by passing the composite nonwoven elastic web through the nip between the rollers. These rollers may be unheated after forming the composite nonwoven elastic web and prior to relaxing the cohesive fibrous nonwoven web. Adhesion can be further enhanced by applying an adhesive to the surface of the tacky fibrous nonwoven elastic web prior to forming the gatherable web.

The composite nonwoven elastic web is then relaxed to its normal relaxed, non-biased length. The fibrous non-woven gatherable web is bonded to the cohesive fibrous non-woven elastic web while keeping the cohesive fibrous non-woven elastic web in the stretched state so that the composite non-woven elastic web, and thus the cohesive fibrous non-woven web Relaxing the woven elastic web pulls the gatherable web onto the shrinking fibrous non-woven elastic web to gather it.

After the fibrous nonwoven gatherable web is gathered, the composite nonwoven elastic web may be wound into a roll for storage and shipping. A second fiber on the exposed side of the tacky fibrous non-woven elastic web prior to the gathering step to avoid adhesion of the tacky fibrous non-woven elastic web on the exposed side during winding of the composite non-woven elastic web. It is preferred to apply a non-woven gatherable web. Alternatively, either before or after gathering, the exposed sticky side of the tacky fibrous non-woven elastic web may be pasted with beef wrapping and stripped prior to utilizing the composite non-woven elastic web. afterwards,
The composite nonwoven elastic web can be utilized to form a wide range of products.

The present invention is also directed to a composite non-woven elastic web comprising a non-woven elastic web bonded to a gathered fibrous non-woven gatherable web, the composite non-woven elastic web performing the method of the present invention. Formed by any of the example methods. In particular, the composite nonwoven elastic web, in its relaxed and unstretched state, is a gathered fibrous nonwoven fabric as a result of relaxing the nonwoven elastic web from an extended stretch-biased length to a relaxed non-biased unstretched length. It consists of a non-woven elastic web bonded to a woven gathered web. Examples of elastomeric materials that can be used to form the fibrous nonwoven elastic web include polyester elastomeric materials, polyurethane elastomeric materials and polyamide elastomeric materials. Other elastomeric materials that can be used to form the fibrous nonwoven elastic web include (a) A-B-A 'block copolymers, where A and A'are thermoplastic polymer ends each containing a styrene component. Block, A may be the same thermoplastic polymer end block as A ', B is an elastomeric polymer midblock such as a conjugated diene or lower alkene), (b) one or more A type of polyolefin or poly (alpha-methylstyrene) and an A-B-A 'block copolymer (where A and A'are thermoplastic polymer end blocks each containing a styrene component, and A is A'. It may be the same thermoplastic polymer endblock as, for example, poly (vinylarene), and B is an elastomeric polymer such as a conjugated diene or lower alkene. There are formulations of the intermediate block is). The A and A'end blocks may be selected from the group containing polystyrene, polystyrene homologues, and the B midblock may be selected from the group containing polyisoprene, polybutadiene, poly (ethylene-butylene). When A and A'are selected from the group containing polystyrene or polystyrene homologues and B is poly (ethylene-butylene), the substances that can be blended with these block copolymers are ethylene, propylene, butene and other lower alkenes or Polymers containing copolymers of one or more of these materials. A
If A and A'are selected from the group containing polystyrene or polystyrene homologues and B is a polyisobrene midblock, the material which can be blended with this type of block copolymer is poly (alpha-methylstyrene).

Preferably, the gatherable web comprises at least one fibrous nonwoven web, which may be meltblown, binderless bonded, or otherwise capable of forming a fibrous nonwoven gatherable web. It includes non-elastic fibers that can be formed by any method. Preferred materials capable of forming a gatherable web include polyester materials, polyolefin materials, or blends of one or more types of polyester materials with one or more types of polyolefin materials. An example of a polyester material is polyethylene terephthalate. An example of a polyolefin material is polypropylene.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Like reference numerals represent similar structures in the drawings,
With particular reference to FIG. 1, meltblown ultrafine fibers 10 formed of a conventional meltblown mold 12 are collected on a porous collection screen 14 which is moving around rollers 18, 20 as indicated by arrow 16. It Melt blown ultrafine fibers 10
The material utilized to form the is an elastomeric material for reasons that will become apparent later. The porous collection screen 14 is driven by rotating rollers 18, 20,
These rollers are driven by a conventional drive device (not shown). Also, although not shown for simplicity, a conventional vacuum box is installed between the rollers 18, 20 under the lower surface of the upper portion of the screen 14. The vacuum box serves to hold the ultrafine fibers 10 on top of the screen 14. As the meltblown ultrafine fibers 10 are deposited on the moving collecting screen 14, they intertwine and agglomerate to form an agglomerated fibrous nonwoven elastic web 22.
The entangled and agglomerated fibrous nonwoven elastic web 22 is carried by the porous collection screen 14 to the nip, or gap 24, between the rotating roller 20 and the rotating nip roller 26. This nip, or gap 24, adjusts to ensure that the rollers 20, 26 engage the fibrous, non-woven elastic web 22 securely without adversely affecting it. roller
Porous collection screen moving at peripheral velocities of 20, 26
The rotation speeds of the rollers 20 and 26 are adjusted so as to be almost the same as the speed of 14. The melt-blown ultrafine fibers 10 are not sufficiently agglomerated when placed on the surface of the porous screen 14 and will be described below without adverse effects (eg, web separation and loss of integrity when subjected to stretching forces). If it is not possible to form a cohesive web 22 that is capable of performing the stretching and relaxation steps, for example to improve the mutual cohesion of the microfibrils 10, the roller 26 may, for example, be brought to some suitable elevated temperature (the desired degree of coagulation or The microfibrils 10 may be heat bonded to each other by maintaining the microfibrils 10) depending on the nature of the material used to form the microfibrils 10. Typical heat bonding temperature range is web
Ranging from about 50 ° C. below the melting temperature of at least one of the materials utilized to form 22 to at least one melting temperature of the materials utilized to form web 22. However, at higher throughputs, temperatures above the melting temperature of the material may be used. After passing through the nip 24, the nonwoven elastic web 22 advances into a second nip formed between the rotating roller 30 and the second rotating nip roller 32 by the action of the rollers 20, 26, i.e., the gap 28, where Pass through.
The rotation of the rollers 30 and 32 is adjusted so that the peripheral surface speed of the rollers 30 and 32 is higher than the peripheral surface speed of the rollers 20 and 26. The nip 28 between the two rollers 30, 32 is adjusted so that the rollers 30, 32 engage securely with the fibrous nonwoven elastic web 22 without adversely affecting it. Laura 2
As a result of increasing the peripheral speed of the rollers 30 and 32 as compared with the peripheral surface drive of 0 and 26, a longitudinal or machine direction (MD) bias force is applied to the fibrous non-woven elastic web 22 and stretches in this direction. The extension bias is extended to the length. The degree of stretch of the fibrous non-woven elastic web 22 occurring in the region 34 between the rollers 20, 26 and the rollers 30, 32 may be, for example, the roller 20,
It can be changed by changing the peripheral speeds of the rollers 30 and 32 with respect to the peripheral speed of 26. For example, Laura 3
If the peripheral velocity of 0,32 is twice that of the rollers 20,26, the fibrous nonwoven elastic web 22 is about twice the original relaxed, non-stretched, non-biased length, or about 200 percent. It will be stretched to the stretch length. In particular, the fibrous nonwoven elastic web 22 has at least about 15 of its relaxed, non-biased length.
It preferably extends from 0 percent to about 700 or more percent.

The fibrous nonwoven elastic web 22 includes rollers 20, 26 and rollers 30, 32.
After stretching due to the combined action of the webs 22, the web 22 moves to a second porous collection screen 36 which is moving as indicated by arrow 38 in FIG. This second porous collection screen 36
Moves around the roller 30 which rotates with the rotating roller 40 and is driven thereby. The rotating rollers 30, 40 are driven by a conventional driving device (not shown). This drive may be the same device that drives the rotating rollers 18,20. Roller, not shown for simplicity
An ordinary vacuum box is installed under the lower surface of the upper portion of the screen 36 between the points 30 and 40. This vacuum box helps hold the web 22 on top of the screen 36. The stretched fibrous non-woven elastic web 22 is rotated by the second porous collecting screen 36 into a rotating roller 40 and a third rotating nip roller.
It is carried to the nip formed between 44, ie the gap 42. The rotations of the rotating roller 40 and the nip roller 44 are adjusted so that the peripheral surface speeds of the two rollers 40 and 44 are substantially the same as the peripheral surface speeds of the rollers 30 and 32. The circumferential velocity of the rollers 40,44 is kept about the same as that of the rollers 30,32, and the nip 42 is adjusted to make the rollers 40,44 fibrous non-woven elastic web.
Due to the firm retention of the fiber 22, the stretched state of the fibrous nonwoven elastic web 22 is maintained while it is being carried by the second porous collection screen 36.

While the stretched fibrous nonwoven elastic web 22 is being carried by the second porous collection screen 36, meltblown microfibers 46 formed of a conventional meltblown mold 48 are placed on top of the stretched nonwoven elastic web 22. Directly meltblown to form a cohesive fibrous nonwoven gatherable web 50 located on top of a stretched fibrous nonwoven elastic web 22. Note that the distance between the meltblown mold 48 die tip and the elastic web 22 as well as the speed at which the elastic web 22 passes under the meltblown mold 48 die tip is adjusted. Depending on the material or blend of materials forming the elastic web 22, the hot air present in the mold tip could cause the elastic web to fail if these adjustments were not made correctly.
This is because it was found that 22 would be melted. As meltblown microfibers 46 are collected on the upper surface of the fibrous nonwoven elastic web 22, the meltblown microfibers entangle with each other to form an agglomerated fibrous nonwoven gatherable web 50. Meltblown painter
Depending on the distance between the 48 die tips and the stretched fibrous nonwoven elastic web 22, the meltblown microfibers 46 may also mechanically entangle with the fibers of the elastic web 22. Broadly speaking, as the distance between the meltblown mold 48 die tip and the upper surface of the stretched fibrous nonwoven elastic web 22 increases, the rate at which the fibers of web 50 and the fibers of web 22 mechanically entangle are reduced. . To ensure mechanical entanglement of web 50 fibers and web 22 fibers, the distance between the meltblown mold 48 die tip and the top surface of web 22 should be no greater than about 25 inches. Preferably, this distance should be in the range of about 6 inches to about 16 inches. Some adhesion of the fibers of the gatherable web 50 to the fibers of the elastic web 22, depending on the material utilized to form the webs 22, 50 and the distance between the die tip of the meltblown mold 48 and the top surface of the web 22. Can also occur. Suitable materials for use in forming the fibrous nonwoven elastic web 22 are preferably fibrous nonwoven gatherable webs 50.
Select after selecting the material to be used for forming. In particular, the material selected to form the fibrous non-woven gatherable web 50 is a web 50 that can be gathered by the shrink force of the fibrous non-woven elastic web 22.
Must be the material forming the. Since the shrinking force of the web 22 depends on the material chosen to form it,
The material chosen for forming the web 22 must be chosen so that the gathering power of the web 22 can gather the web 50. Examples of materials used to form the webs 22, 50 are described below.

Depending on the desired properties of the final product, the materials used to form the fibers that make up the webs 22,50, and the process steps / conditions used therein, the two cohesive webs 22,50 can be joined together in various ways. . For example, when forming the fibrous non-woven gatherable web 50 on the stretched surface of the fibrous non-woven elastic web 22 if one desires that the two webs 22, 50 be relatively weakly bonded to each other. Two webs 22, only by interlocking the individual meltblown fibers of the fibrous nonwoven gatherable web 50 with the individual meltblown fibers of the fibrous nonwoven elastic web 22;
The 50 may be linked together. In this embodiment, the two webs 22, 50 can be separated from each other when a relatively small force is applied, for example a picking or rubbing force applied by a human finger. If it is desired to bond the two cohesive webs 22,50 to each other more strongly, the bonding of the fibrous non-woven gatherable web 50 to the fibrous non-woven elastic web 22 heat bonds the two webs 22,50 to each other. By doing so, the fibrous nonwoven elastic web 22 may be maintained while maintaining its stretched length. This thermal bonding can be done, for example, by rolling the web 22, 50
This can be achieved by placing the rollers 40, 44 between the two 40, 44 so as to apply the appropriate heat bonding temperature and pressure to the two webs 22, 50. For example, a fibrous nonwoven elastic web 22
Bonding the fibrous nonwoven gatherable web 50 to the web 22, 50 from the melting point of at least one of the materials used to form the web 22, 50 to the rollers 40, 44 from about 50 ° C. This may be done by heat bonding the two webs 22, 50 together while maintaining a temperature range up to the melting temperature of at least one of the materials used to form them. However, at high treat rates, the short exposure of the two webs 22, 50 to high temperatures results in
Thermal bonding may be performed at a temperature above the melting point of one or both of the materials used to form the webs 22,50.
By adjusting the nip 42, pressure heat bonding of the two webs 22, 50 to each other may be performed with normal and suitable bonding pressure. Other methods of heat bonding the two webs 22, 50 to each other may be used. For example, thermal bonding devices 40, 44 may be replaced by conventional sonic bonding devices (not shown).
It should be noted here that the mutual coupling of the two webs 22, 50 can be improved somewhat by simply passing the webs 22, 50 through the nip 42. This is because the two webs 22,50 are subject to pressure when passed through the nip, increasing the entanglement of the individual fibers of the two webs 22,50.

After the fibrous nonwoven elastic web 22 is bonded to the fibrous nonwoven gatherable web 50 (either separably or non-separably depending on the desired end product) to form the composite nonwoven elastic web 52. , Loosen the biasing force applied to the fibrous nonwoven elastic web 22. This is a nip, or gap, formed by a pair of rotating nip rollers 56, 58, for example, a composite nonwoven elastic web 52, which includes both the fibrous nonwoven elastic web 22 and the fibrous nonwoven gatherable web 50.
This is done by passing through 54. The nip 54 is adjusted so that the rollers 56, 58 engage the composite nonwoven elastic web 52 securely without adversely affecting it. The rotation of the nip rollers 56, 58 is adjusted so that the peripheral velocity of the nip rollers 56, 58 causes the composite nonwoven elastic web 52 to relax and its elasticity causes it to contract to a relaxed, non-biased length. Relaxation of the composite nonwoven elastic web 52 to its relaxed, non-biased length, contraction causes the fibrous nonwoven gatherable web 50 bonded to the fibrous nonwoven elastic web 22 to move together, i.e.,
Gathering is performed on the top surface of the shrinking and shrinking fibrous nonwoven elastic web 22.

After the composite nonwoven elastic web 52 is relaxed and contracted, the composite nonwoven elastic web 52 is wound onto a supply roller 60 for storage and transportation. The composite nonwoven elastic web 52 can then be utilized to make an outer cover material for a variety of products, such as diapers and other garments.

Alternatively, if the gathered nonwoven web 50 is intended to be separated from the nonwoven elastic web 22, in this embodiment the fibrous nonwoven gathered web 50 is nipped 62 between two rotating nip rollers 64, 66. And the nonwoven elastic web 22 is separated from each other by passing the nonwoven web 22 through the nip 68 between the two rotating nip rollers 70, 72. Adjust the nips 62, 68 so that the rollers 64, 66 are
And the rollers 70, 72 engaging without adversely affecting it
To engage the web 22 without adversely affecting it. After separation of the two webs 22,50, these webs 22,50 are wound onto storage rolls 74,76, respectively. At this point, care must be taken when winding the fibrous nonwoven gathered web 50 so that it is not gathered and stored under high tension or bias. If web 50
It is possible that web 50 will lose its ability to retain its gather if it is stored in a tensioned non-gathered roll. When the gathers on the web 50 are gone, the elasticity of the web 50 is gone. Therefore, in order to keep the gathered state of the web during storage, the rotation of the storage roll 76 can be adjusted to
The peripheral speed of the roller is approximately equal to the peripheral speed of the rollers 64, 66,
Alternatively, it should be slightly larger than that.

Upon separation from the nonwoven elastic web 22, the gathered fibrous nonwoven web 50 has a creped or gathered appearance. Thus, when an extension force is applied in the machine direction (ie, at a direction substantially perpendicular to the gather line), the web 50 will, to the extent that the gather allows, for example, the web 50.
Stretches to a substantially flat configuration different from the gathered configuration, and, surprisingly, when the stretching force on the gathers is removed, the gathered web 50 has the elasticity defined herein. Even when the web 50 was made of a non-elastic material, such as polypropylene sold under the tradename PF301 by Himont Corporation, the gathered web 50 was elastic.

The fibrous nonwoven elastic web 22 portion of the composite nonwoven elastic web 52 may be formed of any elastomeric material capable of forming it. Examples of elastomeric materials that can be used to form the fibrous nonwoven elastic web 22 include, for example, EI
DuPont DeNemours & Co. under the tradename Hytrel polyester elastomer material, for example BFGoodrich & Co. under the tradename Estane polyurethane elastomeric material, for example Rilsan Company under the tradename Pebax. There are polyamide elastomer materials available on the market. Other elastomeric materials used to form the fibrous nonwoven elastic web 22 include (a) elastomeric A-B-A 'block copolymers, where A and A'each contain a styrene component. A plastic polymer end block, where A is A '
The same thermoplastic polymer end block as described above, for example, poly (vinyl allene) may be used, and B is an elastomer polymer mid block such as a conjugated diene or a lower alkene) or (b ) One or more polyolefins or poly (alpha-methyl styrene) and elastomeric AB-A 'block copolymer end blocks, where A and A'are each a thermoplastic polymer end block containing a styrene component. And A may be the same thermoplastic polymer endblock as A ′,
For example, it may be poly (vinyl allene) or B
Is an elastomeric polymer midblock such as a conjugated diene or lower alkene). A,
The A'material may be selected from the group of materials containing polystyrene or polystyrene homologues, and the B material may be selected from the group of materials containing polyisoprene, polybutadiene, poly (ethylene-butylene). This general type of material is described by Des Marais in U.S. Patent No. 4,323,534.
U.S. Pat. No. 4,355,425 to Jones, supra, in the Shell booklet. A commercially available elastomeric ABA 'block copolymer having a saturated or nearly saturated poly (ethylene-butylene) midblock "B" is represented by the following chemical formula:

Here, x, y and n are positive integers. The polystyrene end blocks A and A'are represented by the following chemical formulas.

Here, n is a positive integer which may be the same or different for A and A ′. Sometimes referred to as S-EB-S block copolymer, Shell Ch under the trade name KRATON G
As commercially available from emical Company, KRATON
There are G 1650, KRATON G 1652, and KRATON GX 1657. Other elastomeric resins that can be utilized are ABA 'block copolymers (where A, A'are polystyrene end blocks and "B" are polybutadiene midblocks of the formula:

CH ₂ -CH = CH-CH _{2 n} where n is a positive integer. This material is sometimes S-B
-S block copolymer, called Shell Chemical Compa
from ny under the trade name KRATON D, for example, KRATON D 110
1, KRATON D 1102 and KRATON D 1116 are commercially available. Another SBS block copolymer is Phillips Petro
It can be obtained from leum Company under the trade name Solprene 418. As another elastomer resin, AB-
There are A'block copolymers, where A and A'are polystyrene end blocks as described above, B is a polyisoprene midblock, which midblock is represented by the following chemical formula:

Here, n is a positive integer. These block copolymers are sometimes referred to as SIS block copolymers and are referred to as Shell Ch
Product name KRATON D from emical Company, eg KRATON
D 1107, KRATON D 1111, KRATON D 1112, KRATON D 11
It is commercially available under 17.

A summary of the typical properties of the above KRATON D and KRATON G resins at 74 ° F is shown in Tables I and II below.

1 ASTM Method D412-Tensile Test, Jaw Separation Speed,
Representative properties determined for films cast from 10 in./min. 2 toluene solution 3 Net polymer concentration, 25% w 4 net polymer concentration, measured on cast stretched film cast from 20% w 5 toluene solution Properties determined by extrapolation for zero component of the result 6 Ratio of the sum of the molecular weights of the end blocks (A + A ′) to the amount of separation of the B middle block. For example, for KRATON G-1650, the molecular weight of the end block (A + A ') is 28 percent of the molecular weight of the ABA' block copolymer.

S-EB-S KRATON in pure form, ie net form
Melt blown molding of G block copolymers has been found to be difficult at temperatures of at least about 550 ° F. to about 625 ° F. except at throughputs of less than about 0.14 grams per mold capillary per minute. . To avoid such temperature and low throughput conditions, it has been found that blending one material with some of the different types of KRATON G materials results in a satisfactory meltblown moldable material. For example, blends of certain polyolefin materials with S-EB-S block copolymers have become meltblown moldable materials. In particular, the polyolefin KRAT
When blending with the ON GS-EB-S block copolymer, as the polyolefin, ethylene, propylene,
Butene and other low alkene copolymers or polymers containing blends of one or more of these materials are preferred. A particularly preferred polyolefin for blending with the KRATON GS-EB-S block copolymer is polyethylene, a preferred polyethylene being the trade name Petro thene Na60.
USI at 1 (also called PE Na601 or Na601 here)
It can be obtained from the Chemicals Company.

According to information from USI Chemicals Company, Na601 is a low molecular weight, low density polyethylene for use in the field of hot melt adhesives, coatings. USIChemic
The als Company also says Na601 has the following nominal values: That is, (1) when measured according to ASTM D3236, the Fluckfield viscosity cp is 150.
8500 ° C., 3300 at 190 ° C., (2) a density of 0.903 grams / cubic centimeter when measured according to ASTM D1505, and (3) an equivalent melt index of 2000 grams / 10 minutes when measured according to ASTM D1238. Yes, (4) a ring and ball softening point of 102 ° C as measured according to ASTM E28, and (5) a tensile strength of 850 lbs / in 2 as measured according to ASTM D638, (6) A
When measured according to STM D638, the elongation is 90 percent, the (7) -34 ° C. rigidity T _F is 45,000, and the (8) 7
The penetration hardness at 7 ° F is 3.6.

Na601 has a number average molecular weight (Mn) of about 4600, a weight average molecular weight of about 22400 (Mw), and a Z average molecular weight of about 83300 (Mz).
Are considered to have. The polydispersity (Mw / Mn) of Na601 is about 4.87.

Here, Mn is calculated by the following formula.

Mw is calculated by the following formula.

Mz is calculated by the following formula.

Where MW = various molecular weights of individual molecules in the sample,
n = number of molecules in a given sample with a given molecular weight of MW.

It has been found that when the blend is meltblown after blending the polyolefin with the S-I-S, S-B-S block copolymer, the formulation is unsatisfactory. However, a good material that can be blended with the S-I-S block copolymer is poly (alpha-methylstyrene), a preferred poly (alpha-methylstyrene) is available from Amoco under the tradename 18-210.

Preferably, the fibrous nonwoven gatherable web 50 portion of the composite nonwoven elastic web 52 formed by the method of the present invention can be formed from any gatherable material capable of forming it. For example, the fibrous nonwoven gatherable web 50 may be a blend of non-elastic and elastic materials, one or more non-elastic materials, or one or more elastic materials and two or more elastic materials. It can be formed from blends of more types of inelastic materials. Preferably, the fibrous non-woven gatherable web 50
Is formed from a non-elastic gatherable material that is fiber-forming meltblown moldable or binderless bondable. Examples of fiber forming materials that may be used to form the fibrous nonwoven gatherable web include polyester materials, polyolefin materials, one or more types of polyester materials and one or more types of polyester materials. There are blends of polyolefin materials. An example of a polyester fiber forming material is polyethylene terephthalate. An example of a fiber forming polyolefin material is polypropylene. A preferred polypropylene material is available from Himont Company under the trade name PC973, PF301.

Himont PC-973 polypropylene's typical Himont characteristics are: a density of about 0.900 grams / cubic centimeter measured according to ATEM D792 and a melt flow rate of Condition L of 35 grams / 10 minutes measured according to ATEM D1238. , A
A tensile strength of about 4300 pounds per square inch (psi) measured according to TEM D638, a flexural modulus of about 182000 measured according to ASTM D790, B, and a measurement according to ASTM D785A.
It has an R scale of 93 and a Rockwell hardness. PC-97
It is believed that 3 has a number average molecular weight (Mn) of about 40100, a weight average molecular weight of about 172000, and a Z average molecular weight of about 674000. The polydispersity (Mw / Mn) of PC-973 is about 4.29.

If it is desired to separate the fibrous non-woven gatherable web 50 from the non-woven elastic web 22 after gathering, the fibrous non-woven gatherable web 50 will be gathered during separation from the non-woven elastic web 22. It is preferable to be able to substantially return to. In most embodiments, the web 22
The FG 50 has a gathered state (e.g., morphology) upon separation from the tongue in the gathering direction (i.e., machine Direction) is currently considered to be somewhat longer. In other words, the web 50
Will extend somewhat in the gathering direction after separation from the web 22. Accordingly, the gathered relaxed non-biased length of the separated web 50 will be somewhat greater than or equal to the gathered relaxed non-biased length of the same amount of web 50 as it was bonded to the elastic web 22.

In one particular embodiment of the present invention, composite nonwoven elastic web 52 comprises fibrous nonwoven elastic web 22 bonded to fibrous nonwoven gatherable web 50. The composite nonwoven elastic web 52 of this embodiment is the composite nonwoven elastic web 52 of the above-described embodiment.
Differs from: That is, the bonding of the two webs 22, 50 of the composite nonwoven elastic web 52 is accomplished without the application of heat and / or pressure during the bonding step, yet the fibrous nonwoven gatherable web 50 is nonwoven elastic. The fibers of web 50 are web 22 while being formed on web 22.
It is stronger than the bond obtained by entanglement with the fibers of. In this particular embodiment, the fibrous non-woven elastic web 22 is made of a tacky elastomeric material and thus the fibrous non-woven elastic web 22 is tacky during formation. The tacky fibrous nonwoven elastic web 22 is formed by melt blown molding onto the porous collection screen 14. Alternatively, a tacky nonwoven elastic porous film (not shown) may be used in place of the tacky fibrous nonwoven elastic web 22. Then the adhesive fibrous non-woven elastic web 22
A roller 20, 26 and at least about 1 ^1/4 of the total work by relaxing the unbiased length of the roller 30 and _32, i.e., brought into stretched to stretch a length of at least about 150 percent. In particular, it is preferred that the tacky fibrous nonwoven elastic web 22 be stretched to a length of from about 150 percent to about 700 percent of its relaxed, non-biased length.

After stretching the tacky fibrous nonwoven elastic web 22, the nip between the rotating roller 40 and the rotating nip roller 44, i.e.,
This fibrous nonwoven elastic web 22 is carried by the second porous collecting screen 36 to the gap 42. A fibrous nonwoven gatherable web 50 is formed directly on top of the tacky fibrous nonwoven elastic web 22 while the web 22 is being carried by the second porous collection screen 36. To do this,
Either a conventional meltblown molding method or a binderless bonding method, or any other conventional method available for forming fibrous nonwoven gatherable webs 50, such as forming a card web. It may be a conventional carding device. Similar to the previously described embodiment, when the fibrous nonwoven gatherable web 50 is formed on the surface of the web 22, the tacky fibrous nonwoven elastic web 22 causes the peripheral speed of the rollers 30, 32 to be reduced. Against Laura
The extension bias length is maintained by adjusting the peripheral velocity of 40 and 44 appropriately. Due to the fact that the nonwoven elastic web 22 is tacky during its formation, during the formation of the fibrous nonwoven gatherable web 50 onto the upper surface of the nonwoven elastic web 22, the two webs 20, 50 interact with each other. Adhesion improves the bonding (compared to bonding the web only by entanglement). As a result, the fibrous nonwoven gatherable web 50 is simultaneously formed and bonded to the SB22. Although any tacky elastomeric material can be used to form the tacky fibrous nonwoven elastic web 22 of this embodiment, the preferred tacky elastomeric material is Elastomer A.
There are -BA 'block copolymers. Where A and A'are each thermoplastic polystyrene end blocks and B is a polyisoprene midblock. This type of triblock copolymer material is sometimes referred to as a S-I-S block copolymer and has a trade name of KRATON D, such as KRAT.
ON D1107, KRATON D1111, KRATON D1112, KRATON D1117
Commercially available from Shell Chemical Company. Alternatively, a blend of S-I-S block copolymer and poly (alpha-methylstyrene) can be utilized.

The material that can be utilized to form the fibrous nonwoven elastic web 50 of this embodiment can be any of the materials described above for the fibrous nonwoven gatherable web 50. That is, the fibrous nonwoven gatherable web can be formed of any gatherable material that can be formed into the fibrous nonwoven gatherable web 50. For example, the fibrous nonwoven gatherable web 50 may be a blend of non-elastic and elastic materials, one or more non-elastic materials, or one or more elastic materials and two or more elastic materials. It can be formed from blends of the above types of inelastic materials. Preferably, the fibrous nonwoven gatherable web 50 is made of a meltblown moldable or binderless bondable non-elastic gatherable material for forming fibers. However, the fibrous non-woven gatherable web 50 may be adhered to the face of the SB 22 with a card web, or by any other method available to form the non-woven fibrous gatherable web 50 on the face of the web 22. Can be formed. Examples of fiber forming materials that can be used to form the fibrous nonwoven gatherable web 50 include polyester materials, polyolefin materials or one or more polyester materials and one or more polyolefin materials. There are formulations. An example of the polyester fiber forming material is polyethylene terephthalate. An example of a fiber forming polyolefin material is polypropylene. A preferred polypropylene material is commercially available from Himont Company under the trade name PC973, PF301.

In some situations, during formation of web 22, 50, web 22,
It may be desirable to include one or both of the 50 with one or more loose particles of solid material. For example, it may be desirable to include one or more types of fibers or other particles such as cotton fibers, wood pulp fibers, polyester fibers in one or both webs 22, 50 during formation. This can be done utilizing conventional sub-molding equipment with either meltblown molding equipment or binderless bonding equipment 12 or 48 or both. Such sub-molding equipment is well known to those skilled in the art and is described in Anderson U.S. Pat.
The device disclosed in the publication shows a general structure.

After forming the fibrous non-woven gatherable web 50 on the upper surface of the tacky fibrous non-woven elastic web 22 and at the same time bonding,
The composite nonwoven elastic web 52 is passed through rollers 40,44. These rollers do not require heating for the reasons mentioned above,
Alternatively, no additional pressure need be applied to the composite nonwoven elastic web 52. Thereafter, the stretching bias force applied to the tacky nonwoven elastic web 22 is reduced to relax the composite nonwoven elastic web 52. Because the fibrous nonwoven gatherable web 50 is bonded to the tacky fibrous nonwoven elastic web 22 while the viscous nonwoven elastic web 22 is in the stretched state, the composite nonwoven elastic web 52 relaxes and contracts. The fibrous nonwoven gatherable web 50 is then shrunk together and gathered into a soft cot or mat web 50 bonded to the face of the elastic web 22.

Example I Polystyrene A, A'end block and poly (ethylene-butylene) "B" midblock (trade name KRATON GX165.
A obtained from Shell Chemical Company in 7)
A preformed fibrous nonwoven elastic web formed by melt blown a blend of 60 weight percent of B-A 'block copolymer and 40 weight percent of polyethylene (trade name PE Na601, obtained from USIC Chemical Company). Was prepared in a winding form.

Meltblown molding of fibrous nonwoven elastic webs was accomplished by extruding the material blend through a meltblown mold having 30 extrusion capillaries per linear inch of mold tip. Each capillary had a diameter of about 0.0145 inch and a length of about 0.113 inch. The formulation was extruded through the capillaries at a rate of about 0.52 grams per minute per capillary at a temperature of about 595 ° F. The pressure at which the formulation was extruded was 73 pounds per square inch gauge at the capillary. The mold tip morphology was adjusted to be recessed approximately 0.090 inches inward from the plane containing the outer surface of the air plate which forms the molding air gaps on both sides of the capillary.
The air plate was adjusted so that a total of two molding air gaps, one on each side of the extrusion capillary, formed an air gap of about 0.067 inches. Molding air to meltblown the compound at a temperature of about 600 ° F and about 4 pounds /
The air gap was supplied at a pressure of a square inch gauge. The meltblown fiber thus formed is almost
It was sprayed onto the forming screen at 15 inches.

The fibrous non-woven elastic web thus formed is unwound and stretched by applying a tensioning force, that is, a biasing force in the machine direction (MD) to keep the fibrous non-woven elastic web at its stretched length A fibrous nonwoven gatherable web was formed by melt blown polypropylene (trade name PC973, marketed by Himont Company) into ultrafine fibers on the top surface of an elastic web.

Meltblown molding of fibrous nonwoven gatherable webs was accomplished by extruding polypropylene through a meltblown mold having 30 extrusion capillaries per linear inch of mold tip. Each capillary had a diameter of about 0.0145 inch and a length of about 0.113 inch. Polypropylene is about 590 ° F at a rate of about 0.38 grams per minute per capillary
Extruded through a capillary at a temperature of. The extrusion pressure applied to the polypropylene was 29 pounds per square inch gauge at the capillary. The mold tip morphology was adjusted so that it was positioned substantially flush with the plane containing the outer surface of the air plate forming the molding air gaps on both sides of the capillary. The air plate was adjusted so that a total of two molding gaps, one on each side of the extrusion capillary, created an air gap of about 0.015 inch. Molding air for melt blown polypropylene is about
The air gap was fed at a temperature of 600 ° F. and a pressure of about 4 pounds per square inch gauge. The melt-blown polypropylene microfibers thus formed are almost
A diameter meltblown was formed on top of a fibrous nonwoven elastic web located at inches. Due to these processing conditions, the viscosity of polypropylene was about 20 poise, forming very small diameter polypropylene microfibrils in the face of the fibrous nonwoven elastic web.

The stretch bias force was then reduced, the fibrous nonwoven elastic web was contracted, and the meltblown molded polypropylene web was gathered in the machine direction. The composite nonwoven elastic web thus formed has apparently interlayer bondability resulting from the interlocking of the individual fibers of these webs because the two webs are not adhesively or heat bonded. It was

A sample of the fibrous nonwoven elastic web itself and a sample of the composite nonwoven elastic web were stretched in an Instron Tensile Tester Model 1122 to obtain 100 percent of each sample, ie, twice the elongation of the unstretched length, and then the sample. Was returned to the non-stretched state. This procedure was repeated 3 times, after which each sample was extended to break. Each sample is 2 inches wide,
It was 5 inches long and the initial jaw separation on the tester was set to 1 inch. The sample was placed vertically in the tester and stretched at a rate of 5 inches per minute. Machine direction data was obtained from a sample having a machine direction length of 5 inches and a lateral width of 2 inches. Transverse measurements were obtained from samples having a length of 5 inches in the cross direction and a width of 2 inches in the machine direction. The data obtained for the fibrous nonwoven elastic webs are shown in Table III below, and the data obtained for the composite nonwoven elastic webs are shown in Table IV below.

Tables III and IV show the total absorbed energy (inches-pounds), the peak (maximum) load (pounds) produced at each iteration,
Each peak (maximum) elongation (inches) is disclosed when the sample is stretched and when the sample is stretched to break in each iteration of the 100 percent stretch procedure. As can be seen, the total energy required to stretch a 100 percent sample in the machine direction at peak load is about the same for fibrous and composite nonwoven elastic webs.
This is believed to be because the meltblown polypropylene web is gathered in the machine direction and requires less energy to stretch in the machine direction. Upon elongation at break, the peak load for the composite nonwoven elastic web increased by more than 70 percent. This indicates that the melt blown polypropylene web imparts strength to the strength of the composite nonwoven elastic web.

In the transverse direction (TD) (melt gather blown polypropylene ungathered), the peak load for the initial strength of the composite nonwoven elastic web is more than 60 percent greater than the peak load for the fibrous nonwoven elastic web. This indicates that the melt blown polypropylene web contributes to the strength of the composite nonwoven elastic web even at low elongations. Furthermore, it is shown that the peak total absorbed energy for the composite nonwoven elastic web was increased by 50 percent over that of the fibrous nonwoven elastic web at the first stretch. In the subsequent stretching phase this value actually decreases. This indicates that upon initial stretching, the meltblown molded polypropylene web was severely broken or torn and no longer contributes to the total energy of the composite nonwoven elastic web.

Here, it was observed that the "breathability" of the composite nonwoven elastic web was still better than the "breathability" of the fibrous nonwoven staged web. Furthermore, due to the thin web of melt blown polypropylene ultrafine fibers applied to the surface of the fibrous nonwoven elastic web, the water repellency of polypropylene further enhances its water repellency. In addition, melt blown molding
By applying a thin web of melt blown microfibers to the surface of the FB, the rubbery feel of the non-woven elastic web was changed to a soft and desirable feel.

Example II Polystyrene A, A'end block and poly (ethylene-butylene) "B" midblock (trade name KRATON GX165
A obtained from Shell Chemical Company in 7)
A preformed fibrous nonwoven elastic web formed by melt blown a blend of 60 weight percent of B-A 'block copolymer and 40 weight percent of polyethylene (trade name PE Na601, obtained from USIC Chemical Company). Was prepared in a winding form.

Meltblown molding of fibrous nonwoven elastic webs was accomplished by extruding the material blend through a meltblown mold having 30 extrusion capillaries per linear inch of mold tip. Each capillary had a diameter of about 0.0145 inch and a length of about 0.113 inch. The formulation was extruded through the capillaries at a rate of about 0.50 grams per minute per capillary at a temperature of about 570 ° F. The pressure at which the formulation was extruded was 144 pounds per square inch gauge at the capillary. However, it is currently believed that this measurement was inaccurate due to failure of the pressure probe. The mold tip morphology was adjusted to be recessed about 0.110 inch inward from the plane containing the outer surface of the air plate forming the molding air gaps on both sides of the capillary. The air plate was adjusted so that a total of two molding air gaps, one on each side of the extrusion capillary, formed an air gap of about 0.110 inch. Molding air for meltblown molding the formulation was supplied to the air gap at a temperature of about 614 ° F and a pressure of about 4 pounds per square inch gauge. Meltblown fibers were formed into a forming screen that was believed to have been approximately 16 inches from the die tip. This distance was not measured accurately.

The fibrous non-woven elastic web thus formed is unwound and stretched by applying a tensioning force, that is, a biasing force in the machine direction (MD) to keep the fibrous non-woven elastic web at its stretched length A fibrous nonwoven gatherable web was formed by melt blown polypropylene (trade name PF301, marketed by Himont Company) into ultrafine fibers on the top surface of an elastic web.

Meltblown molding of fibrous nonwoven gatherable webs was accomplished by extruding polypropylene through a meltblown mold having 30 extrusion capillaries per linear inch of mold tip. Each capillary had a diameter of about 0.0145 inch and a length of about 0.113 inch. Polypropylene is about 590 ° F at a rate of about 0.75 grams per minute per capillary
Extruded through a capillary at a temperature of. The extrusion pressure applied to the polypropylene was 186 pounds per square inch gauge at the capillary. The mold tip morphology was adjusted to position about 0.010 inch above the plane containing the outer surface of the air plate forming the molding air gaps on both sides of the capillary. Adjust the air plate, one on each side of the extrusion capillary for a total of 2
The two molded air gaps formed an air gap of about 0.018 inch. Molding air for melt blown polypropylene was supplied to the air gap at a temperature of about 600 ° F. and a pressure of about 2 pounds per square inch gauge. The distance between the mold tip and the surface of the fibrous nonwoven elastic web forming the gatherable polypropylene web was about 10 inches. Due to these processing conditions, the viscosity of the polypropylene was about 124 poise, forming larger diameter polypropylene microfibrils on the face of the fibrous nonwoven elastic web.

The stretch bias force was then reduced, the fibrous nonwoven elastic web was contracted, and the meltblown polypropylene web was gathered in the machine direction. The composite nonwoven elastic web thus formed has apparently interlayer bondability resulting from the interlocking of the individual fibers of these webs because the two webs are not adhesively or heat bonded. It was

A sample of the fibrous nonwoven elastic web itself and a sample of the composite nonwoven elastic web were stretched in an Instron Tensile Tester Model 1122 to obtain 100 percent of each sample, ie, twice the elongation of the unstretched length, and then the sample. Was returned to the non-stretched state. This procedure was repeated 3 times, after which each sample was extended to break. Each sample is 2 inches wide,
It was 5 inches long and the initial jaw separation on the tester was set to 1 inch. The sample was placed vertically in the tester and stretched at a rate of 5 inches per minute. Machine direction data was obtained from a sample having a machine direction length of 5 inches and a lateral width of 2 inches. Transverse measurements were obtained from samples having a length of 5 inches in the cross direction and a width of 2 inches in the machine direction. The data obtained for the composite nonwoven elastic web formed in Example II is shown in Table V below.

This Table V shows that when the composite nonwoven elastic web is stretched to break in the machine direction, the machine direction energy or load required for 100% elongation is low, the total absorbed energy increases about 7 times, and the peak This indicates that the load has increased about three times. In the transverse direction, where the meltblown body is not gathered, the initial 100% elongation absorbs about 3.5 times the total absorbed energy up to break, and any subsequent 100% stretching effects will be about 40 to 5%. Absorbed twice the energy. Moreover, the peak load for the first stretch in the transverse direction was about 40 percent higher than the peak load for any subsequent stretch in the same transverse direction.

By the constant value, the peak TEA was 2.376, the peak load was 1.232, and the peak elongation was 5,609. These values are considered incorrect because they are too far from the values obtained in the other two measurements.

Unless stated otherwise, it is understood that the data listed in Tables III, IV, and V are averages obtained from five measurements for each machine direction identification and three measurements for each lateral measurement. I want to be done.

The basis weight of the meltblown molded fibrous nonwoven elastic web used in Example I was 67.3 grams / square basis and the meltblown molded gathered load polypropylene formed on the surface of the fibrous nonwoven elastic web of Example I. The basis weight of the web was 12.2 grams / square meter. The degree of relaxation or shrinkage of the composite nonwoven elastic web of Example I was about 54 percent. The degree of relaxation of the composite nonwoven elastic web was determined by taking a sample of the composite nonwoven elastic web with a relaxed length of about 4.0 inches in the machine direction and stretching the sample in the machine direction until it resisted elongation by the gathered polypropylene web. It was decided by stretching. That is, until the polypropylene web is gathered. At this point, the 4.0 inch sample stretched approximately 8.75 inches in the machine direction.

The fibrous nonwoven elastic web used in Example II had a basis weight of about
66.2 grams / square meter, and the basis weight of the fibrous nonwoven gatherable web meltblown on the surface of the elastic web in Example II was about 21.4 grams / square meter. The degree of relaxation or shrinkage of the composite nonwoven elastic web of Example II was about 42 percent. This degree of relaxation was formed by taking a sample of a composite non-woven elastic web having a relaxation length of about 12 inches in the machine direction and stretching the sample in the machine direction until resistance to elongation by the gathered polypropylene web. . That is, it is stretched until the polypropylene web is gathered. At this point, the 12-inch sample is about
It has grown to 20.7 inches.

Observation of the relaxed and contracted composite nonwoven elastic web revealed the following. That is, the meltblown polypropylene web has a creped, gathered appearance, and the lines of the crepe or gather are the fibrous non-woven elastic web. It was approximately transverse to the direction in which the web was stretched (ie transverse to the machine direction). Interestingly, the fibrous non-woven elastic web of the shrunken composite non-woven elastic web possesses a crepe or gather line that is approximately parallel to the direction of stretch of the fibrous non-woven elastic web during melt blown polypropylene molding. (Ie, the crepe or gather lines of the fibrous nonwoven elastic web are approximately parallel to the machine direction). Thus, a composite nonwoven elastic web of two webs includes a web having alternate lines of gathers or crepes that cross each other at approximately right angles. The occurrence of gather or crepe lines in a fibrous nonwoven gatherable polypropylene web may be predicted from the gather of that web in the machine direction. However, the formation of gathered or crepe lines in the fibrous non-woven elastic web, and in particular the occurrence of gathered or creped lines in the non-woven elastic web at approximately right angles to the gather or crepe lines of the polypropylene fibrous non-woven gatherable web, is predicted. Was not done.

Approximately 5-7 / 8 inch length in the machine direction (MD) and approximately 4
A portion of the composite nonwoven elastic web having a -transverse dimension (TD) of -1/2 inch was cut out to separate the gathered fibrous nonwoven meltblown polypropylene web from the fibrous nonwoven elastic web. Upon this separation, the gathered fibrous non-woven meltblown polypropylene web has a relaxed machine direction dimension of about 7 inches and about 4-1 /
The lateral dimension of 2 inches was maintained. Importantly, this gathered fibrous non-woven meltblown polypropylene web retained substantially its creped or gathered morphology in the machine direction. In addition, the separate gathered fibrous non-woven meltblown polypropylene web can be stretched in the machine direction by applying a tensioning and biasing force in the machine direction, and when the tensioning biasing force is removed, the relaxation is almost complete. Unbiased, tensionless gather dimensions (7 inch x
Return to 4-1 / 2 inches). That is, it contracted. For example, machine direction (M
When a 7 "x 4-1 / 2" sample of a gathered fibrous non-woven meltblown polypropylene web is stretched in D), this sample is measured to be about 9-1 / 2.
It was found to have a machine direction (MD) length of inches and a transverse (TD) dimension of approximately 4-1 / 2 inches. When the bias force was removed from the sample, the sample returned within just a minute to a machine direction (MD) dimension of just over 7 inches, a transverse (TD) dimension of about 4-1 / 2 inches. When the elongation procedure was repeated, the sample took a machine direction (MD) dimension of about 9-1 / 2 inches and a transverse direction (TD) dimension of about 4-1 / 2 inches. Two
Excluding the second stretch, the polypropylene web had a machine direction (MD) dimension of about 7-1 / 2 inches and a transverse direction (TD) dimension of about 4-1 / 2 inches in less than a minute. This result was unexpected as it was believed that PF301 polypropylene was not elastic.

The method of the present invention and the products formed by this method can vary. For example, two or more fibrous non-woven gathered webs 50 could be stacked one on top of the other to thicken the fibrous non-woven gathered webs 50. Further, one fibrous non-woven gathered web 50 is separable or bonded to both sides of the fibrous non-woven elastic web 22 in the manner described above for the following three web sequences: fibrous non-woven gathered web. A composite non-woven elastic web could be formed having a / fibrous non-woven elastic web / fibrous non-woven gathered web.

A three web sequence of a fibrous non-woven elastic web sandwiched between two fibrous non-woven gathered webs is particularly desirable when the fibrous non-woven elastic web 22 is made of a tacky elastomer material as described above. This is because sandwiching the sticky elastic web 22 with two webs prevents the sticky web 22 from sticking to other parts of the web 52 when the web 52 is wound for storage. The 3 web material could be formed by the method shown schematically in FIG. In this method, a two-layer composite nonwoven elastic web 52 is a roller.
It is the same as the method schematically shown in FIG. 1 until exiting 40 and 42. Thereafter, the composite web 52 passes through the nip 78 between the rotating roller 80 and the rotating nip roller 82 without proceeding to the nip 54 between the rollers 56 and 58. The composite web 52 is then conveyed by the third porous collecting screen 84 to the nip 86 between the rotating nip roller 88 and the rotating roller 74. Porous collection screen
68 is driven by moving around rollers 80, 84 in the direction shown by arrow 92 in FIG. By adjusting the rotation of the rollers 80, 82, 88, 90, the peripheral speed of the rollers 80, 82, 88, 90 can be adjusted by the roller 40,
The same as the peripheral speed of 44. As such, the fibrous nonwoven elastic web 22 is maintained in the stretch bias length as it is carried by the porous collection screen 84.

While the composite nonwoven elastic web 52 is being carried by the porous collection screen 84, a conventional meltblown mold 94 (which may utilize a conventional binderless bond or carding equipment if desired) is woven. A second fibrous nonwoven gathered web 96 is formed on the opposite side of the stretched fibrous non-woven elastic web 22 by melt blown ultrafine fibers 98 directly onto the stretched upper surface of the elastic web 22. The materials that can be used to form the second gatherable web 96 can include any of the materials described above that can be used to form the first fibrous nonwoven gathered web 50. Particulate matter may be included in the web 96 as described above in connection with the webs 22,50. Then the second
Essentially non-woven fibrous web 96 roller 4
It may be heat bonded to the fibrous nonwoven elastic web 22 by the action of rollers 88, 90 equivalent to 0,44. The thermal bonding of the second fibrous nonwoven gathered web 96 to the fibrous nonwoven elastic web 22 is related to the thermal bonding of the first fibrous nonwoven gathered web 50 to the fibrous nonwoven elastic web 22. It can be carried out within the same temperature range and the same pressure range as described above.
If desired, conventional sonic bonding techniques (not shown) may be used in place of the thermal bonding step. Alternatively, if the fibrous non-woven elastic web 22 is tacky, then thermal bonding of the fibrous non-woven gathered web 96 to the fibrous non-woven elastic web is not required, as previously described. This is because the second fibrous non-woven gathered web 96 will be formed on the surface of the fibrous non-woven elastic web 22 and will be bonded thereto at the same time.

In another embodiment, if the fibrous non-woven gathered web 96 is to be separated from the elastic web 22 at a later stage, the second fibrous non-woven gathered web 96 will remove it. The fibers of web 96 may be inseparably bonded to the surface of fibrous nonwoven elastic web 22 by interlocking the fibers of web 96 with the fibers of web 22 during formation on the surface of woven elastic web 22. In this embodiment, the fibrous nonwoven gathered web 96 is formed and bonded to the fibrous nonwoven elastic web 22 at the same time.

In any of these embodiments, the bonding of webs 50, 96 to web 22 can be improved by applying an adhesive to the surface of elastic web 22 prior to forming webs 50, 96 on the stretched surface of web 22. . Application of the adhesive to the surface of the web 22 can be easily done as usual by the nip rollers 32, 82. For example, the adhesive may be commonly applied to the surfaces of the rollers 32, 82 and the rollers 32, 82 transfer the adhesive to the surface of the web 22 as the web 22 passes through the nips 28, 78. Alternatively, the adhesive may be applied to the surface of the web 22 in spot form.

After bonding the fibrous non-woven gathered web 96 to the elastic web 22, a three-web composite non-woven in the nip 102 between the two rotating nip rollers 104, 106 to loosen the biasing force applied to the web 22. Thread the elastic web 100. The rotation of the rollers 104, 106 is adjusted to relax the composite web 100 at the peripheral velocity of the rollers 104, 106. This composite web 100
, Due to its elasticity, contracts to its relaxed, non-biased length. Relaxation and contraction of web 100 to a non-biased length causes both fibrous non-woven gathered webs 50, 96 to gather due to relaxation and contraction of fibrous non-woven elastic web 22. Finally, the composite web 100 can be wound and stored, as shown at 108. The tacky elastic web 22 is sandwiched between the webs 50 and 96 to allow the composite web to be stored during storage.
The tacky elastic web 22 does not adhere to the other parts of 100. This material can be used to form a variety of products, such as diaper products.

It should be appreciated that the two-web composite web 100 described above in connection with the tacky elastic web 22 may also be formed without the tacky material forming the web 22. in this case,
The web 96 must be entangled with fibers on the web 22, and other bonding methods such as heat bonding, sonic bonding, etc. must be utilized.

In another aspect of the invention, the machine direction (MD) as shown
Rather than gathering one or more gatherable webs 50, 96 in the transverse direction (TD). If you want to gather the webs 50 and / or 96 laterally, stretch the elastic web 22 laterally,
Utilizes an additional device for contraction. For example,
FIG. 4 illustrates another embodiment of the present invention that avoids the requirement of forming the gathered nonwoven elastic web 50 of the embodiment of FIG. 1 on the stretched surface of the nonwoven elastic web 22. In the embodiment of FIG. 4, the gathered nonwoven elastic web 50 is formed directly on the surface of the porous forming screen 110, which itself is stretchable in the machine direction as indicated by arrow 112. For example, this stretchable porous collection screen 11
0 can be made from a continuous web of nonwoven elastic web 22. Alternatively, the stretchable porous collection screen 110 may be made of a wire mesh screen 114 generally shown in FIG. The wire mesh screen 114 is formed by a plurality of substantially parallel springs 116 that are coiled in the machine direction and unfold, which springs 116 are laterally separated from each other by a plurality of thin, generally parallel wires 118 extending in the transverse direction (TD). It is connected. The transverse wires 118 are placed in close proximity to each other such that when the mesh screen 114 is in the unbiased, contracted configuration, the transverse wires 118 contact each other. When a tensioning or biasing force is applied in the machine direction, the coil spring 116 expands, or stretches, in the machine direction and the thin transverse wires 118 separate from each other to form the porous collection surface 110. This biased and expanded configuration is shown in FIG.

Alternatively, the wire mesh screen 114 may be formed by a plurality of substantially parallel springs coiled laterally and unrolled, the springs being connected to each other in the machine direction by a plurality of thin parallel wires extending in the machine direction (MD). ing. This configuration is shown in FIG. 5, which allows the web 96 to be gathered in a transverse direction other than the machine direction as shown. If it is desired to gather web 96 laterally, an additional conventional device for stretching screen 114 laterally (not shown) is used in place of the device shown for stretching screen 114 in the machine direction.

As can be seen with reference to FIG. 4, movement of the retractable porous collecting screen 110 in the machine direction 112 is accomplished by being driven by rollers 120,122. These rollers are driven by a conventional drive mechanism (not shown). Although not shown for simplicity, the rollers 120, 122
Below the lower surface of the upper part of the screen 110 between them is a conventional vacuum box. Vacuum box screen
Helps hold web 22 on top of 110. The stretchable porous collecting screen 110 passes through a nip 124 between a pair of rotating nip rollers 126,128. The nip 124 is adjusted to ensure that the rollers 126, 128 securely engage the stretchable porous collecting screen 110 without adversely affecting it. The rotations of the rollers 126 and 128 are adjusted so that the peripheral surface speeds of the rollers 126 and 128 are substantially the same as the peripheral surface speeds of the rollers 120 and 122. Telescopic porous collection screen 110
Is a nip 130 between another pair of rotating nip rollers 132, 134.
By adjusting this nip 130, the rollers 132, 134 engage securely with the porous collecting screen 110 without adversely affecting it. Rollers 132, 134
Adjust the rotation of the roller to adjust the peripheral speed of the rollers 132 and 134.
Increase the peripheral speed of 120 and 122. Rollers 132,134
As a result of the peripheral speed of the roller 120, 122 being higher than the peripheral speed of the rollers 120, 122, a longitudinal or machine direction bias stretching force is applied to the retractable porous collecting screen 110 such that the screen 110 is longitudinal in region 136. Stretch bias extends to length. The extent of stretching of the porous collection screen 110 that occurs in the area 136 between the rollers 126, 128 and between the rollers 132, 134 varies, for example, by changing the peripheral speed of the rollers 132, 134 relative to the peripheral speed of the rollers 126, 128. Can be changed by For example, if the peripheral velocity of rollers 132,134 is about twice the peripheral velocity of rollers 126,128, the expandable porous collection screen 110 is approximately twice its contracted, non-biased length, or about. It will extend to a stretch bias length of 200 percent. Stretchable porous collection screen 110 preferably extends in region 136 to a length of at least about 125 percent of its contracted, non-biased, unstretched length. In particular, screen 110 is preferably stretched in region 136 to a stretch length of at least about 150 percent of its contracted, non-biased, non-stretched length. More preferably, the porous collection screen 110 may extend from at least about 150 percent to about 700 percent or more of the unstretched, non-biased length.

Meltblown microfibers 140 formed by a conventional meltblown mold 140 are meltblown onto the stretched surface of the porous collection screen 110 while the stretchable porous collection screen 110 is in the stretched configuration in region 136. . When the meltblown microfibers 138 are deposited on the stretched porous collection screen 110, they become entangled and agglomerated to form an agglomerated fibrous nonwoven gathered web.
Forming 96. The entangled and agglomerated fibrous nonwoven gathered web 96 is passed through a nip 130 by a porous collection screen 110 to a rotating roller 120 and a rotating nip roller 144.
To the nip 142 formed between the two. Adjust the peripheral speed of the rotating nip roller 144 and adjust it to the rotating roller 12
0 and the peripheral speeds of the rollers 122, 126 and 128 are almost the same.
Since the circumferential velocity of the rollers 144, 120 is about the same as the circumferential velocity of the rollers 122, 126, 128, the stretching force is removed from the stretched porous collecting screen 110, causing the screen 110 to contract and, due to its shrinkability. The contraction is non-biased length. Shrinkage and shrinkage of the porous collection screen 110 to a non-biased length causes the fibrous nonwoven gathered web 96 to shrink together and gather on its upper surface. Therefore,
This gathered action works with paired rollers 132, 134, 120, 1
It occurs in region 146 between 44.

After loosening and contracting the porous collection screen 110, the fibrous nonwoven gathered web 96 may be wound onto a supply roller 148 for storage and shipping. For the reasons previously mentioned, the rotational speed of the feed roller 148 must be controlled to store the gathered fibrous nonwoven elastic web 96 in a substantially untensioned state. This is roller 14
Adjust the rotation speed of 8 to adjust the peripheral speed of roller 148 to that of roller 12.
This is achieved by making the peripheral velocity of 0,144 almost the same, or slightly larger.

When a three-layer composite web is formed as shown in FIG. 3,
It may be desirable to separate the two outer gathered nonwoven webs from the elastic nonwoven web. in this case,
Nip 150 and web 96 between two nip rollers 152, 154 rotating fibrous non-woven gathered web 50.
Nip 15 between two nip rollers 158, 160 rotating
Fibrous nonwoven gathered web by threading through 5
0, 96 are separated from the fibrous nonwoven elastic web 22. The webs 50, 96 are then wound onto their respective storage rolls 162, 164 for later use. For the reasons previously mentioned, care should be taken when winding the fibrous non-woven gathered webs 50, 96 to ensure that the webs 50, 96 are stored on rolls 162, 164 in a tensionless or nearly tension-free condition. There must be. This rotates the rolls 162 and 164,
The surface speed of 162 is equal to or slightly greater than the surface speed of rolls 152, 154,
This can be done by making the peripheral speed of the roller 164 equal to or slightly higher than the peripheral speed of the rollers 158, 160. After separation of the webs 50, 96, the fibrous non-woven elastic web 22 passes through a nip 166 between two rotating nip rollers 168, 170 and is wound onto a storage roller 172.

Although the particular embodiment discussed herein describes fibrous non-woven gathered webs 50, 96 as formed using conventional meltblown molds and meltblown processes, they are instead used for conventional binderless bonding. Mold and binderless bonding methods are available and the scope of the invention is to form binderless bonding molds and methods or meltblown molds and methods 48, 94 to form non-woven gatherable webs. It is intended to include materials formed by any of the devices and methods of. When utilizing the binderless bonding type and method, the bonding of the gatherable web 50 to the fibrous nonwoven elastic web 22 is as described above.
Inner web bonding (when tacky elastomeric material is used to form web 22), thermal or sonic bonding, or by applying adhesive to the surface of web 22 prior to forming webs 50, 96. I have to.
These bonding methods must be utilized with binderless bonded gatherable webs. this is,
The binder-free fibers of the gatherable web are not easily entangled with the fibers of web 22. 1
If you want to bond one or more webs 50, 96 to web 22 by thermal bonding (webs 50, 96 are formed by binderless bonding, melt blown molding, or otherwise), thermal bonding Care must be taken to relax and contract the web 22 to a substantially tension-free, non-biased condition as early as possible after performing the steps. This is believed to be because if the nonwoven elastic web 22 is maintained above the softening point for a long time, it will lose elasticity. The loss of elasticity causes the cold elastic web 22 to "solidify" in the stretched state.

It should be understood that changes and modifications of the present invention can be made without departing from the scope of the invention. Moreover, the scope of the present invention is not limited to the specific embodiments disclosed herein,
It is also to be understood that it is limited only by reading the claims in light of the above description.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing one mode for carrying out the method of one embodiment of the present invention. FIG. 2 is a schematic view for explaining a mode for carrying out the method of another embodiment of the present invention. FIG. 3 is a schematic diagram illustrating the manner in which the method of an embodiment of the present invention for separating a gathered web from an elastic web is performed. FIG. 4 is a schematic diagram illustrating another embodiment for carrying out the method of another embodiment of the present invention for separating a gathered web from an elastic web. FIG. 5 is a top view showing a stretchable forming screen usable as a forming screen in the method shown in FIG. 4 in a non-biased contracted state. FIG. 6 is a top view of the stretchable screen of FIG. 5 in biased stretched configuration. FIG. 7 is a schematic diagram showing an embodiment for carrying out the method of another embodiment of the present invention for separating two gathered webs from an elastic web. In the drawing, 10 ... Meltblown ultrafine fibers, 12 ...
… Meltblown type, 14 …… Porous collection screen, 1
8, 20 ... Roller, 22 ... Fibrous non-woven elastic web, 26 ...
… Nip rollers, 30 …… Rollers, 32 …… Nip rollers,
36 …… Second porous collection screen, 40 …… Roller, 44…
… Nip rollers, 46 …… Melt blown microfibers, 48
...... Melt blown mold, 50 …… Fibrous non-woven gathered web, 52 …… Composite non-woven elastic web, 56,58 …… Nip roll, 60 …… Supply roller, 64,66 …… Nip roller, 70,72… … Nip rollers, 74, 76… Storage roll

Claims (23)

[Claims] 1. A method of making a composite non-woven fibrous web comprising a non-woven elastic web bonded to a fibrous non-woven gather web, the steps comprising providing a non-woven elastic web and the non-woven elastic web. Stretching the fibrous non-woven gatherable web so that it is in direct contact with the surface of the stretched non-woven elastic web, and stretching the fibrous non-woven gatherable web. Bonding to an elastic web to form a composite non-woven elastic web, and loosening the composite non-woven elastic web to gather the fibrous non-woven gatherable web. 2. The method of claim 1, wherein the step of providing the nonwoven elastic web comprises the step of forming a fibrous nonwoven elastic web of meltblown ultrafine fibers. how to. 3. The method of claim 1 wherein the step of providing the nonwoven elastic web comprises the step of providing a porous elastic web. 4. The method of claim 2 wherein the fibrous nonwoven elastic web comprises at least about 125 percent of the relaxed length of the fibrous nonwoven elastic web to about the relaxed length of the nonwoven elastic web. A method characterized by stretching up to 700 percent. 5. The method of claim 1, wherein forming the fibrous nonwoven gatherable web comprises forming a meltblown ultrafine fibrous nonwoven gatherable web. A method of including. 6. The method of claim 1 wherein the step of forming said fibrous nonwoven gatherable web is a binder-free bonded microfine fibrous nonwoven gatherable web. A method comprising forming a. 7. The method of claim 1, wherein forming the fibrous nonwoven gatherable web comprises forming a card web. 8. The method of claim 1, wherein the step of bonding the fibrous nonwoven gatherable web to the nonwoven elastic web is performed by thermal bonding. 9. The method of claim 8 wherein the step of heat bonding the fibrous nonwoven gatherable web to the nonwoven elastic web comprises the steps of: A method comprising thermal bonding within a temperature range from about 50 ° C. below the melting temperature to about the melting temperature of the material utilized to form either web. 10. A method of making a composite non-woven elastic web comprising a non-woven elastic web bonded to a fibrous non-woven gathered web, the method comprising: providing a tacky non-woven elastic web; Stretching the nonwoven elastic web and forming the fibrous nonwoven gatherable web so that it is in direct contact with the surface of the stretched nonwoven elastic web;
Forming the fibrous non-woven gatherable web on the surface of the stretched fibrous non-woven elastic web by bonding the fibrous non-woven gatherable web to the surface of the stretched non-woven elastic web. Adhering these two types of webs together during bonding to form a composite non-woven elastic web by bonding the cohesive non-woven elastic web to a fibrous non-woven gatherable web; Loosening to gather the fibrous non-woven gatherable web. 11. The method of claim 10, wherein providing the tacky nonwoven elastic web comprises forming a meltblown microfiber fibrous nonwoven elastic web. How to characterize. 12. The method of claim 11 wherein the step of forming the fibrous nonwoven gatherable web comprises a binderless bonded microfibril on the surface of the fibrous nonwoven elastic web. Forming a fibrous non-woven gatherable web of. 13. A method of making a composite non-woven elastic web comprising a non-woven elastic web bonded to a fibrous non-woven gathered web, the method comprising: providing a tacky non-woven elastic web; Stretching the nonwoven elastic web and forming the fibrous nonwoven gatherable web so that it is in direct contact with the surface of the stretched nonwoven elastic web;
Forming the fibrous non-woven gatherable web on the surface of the stretched non-woven elastic web by bonding the fibrous non-woven gatherable web to the surface of the stretched non-woven elastic web. Intertwining the individual fibers of the non-woven gatherable web with the non-woven elastic web to bond the tacky non-woven elastic web to the fibrous non-woven gatherable web to form a composite non-woven elastic web. And relaxing the cohesive composite non-woven elastic web to gather the fibrous non-woven gatherable web. 14. The method of claim 13, wherein the step of providing the nonwoven elastic web comprises the step of forming a fibrous nonwoven elastic web of meltblown ultrafine fibers. how to. 15. The method of claim 14 wherein said bonds are individual fibers of a fibrous non-woven gatherable web to individual fibers of a fibrous non-woven elastic web of meltblown microfibrils. A method characterized by being performed only by interlocking. 16. The method of claim 13 wherein the step of providing the nonwoven elastic web comprises the step of providing a porous nonwoven elastic film. 17. The method of claim 16 wherein said bonding is accomplished only by entanglement of individual fibers of the fibrous nonwoven gatherable web with holes in the porous nonwoven elastic film. How to characterize. 18. A method of making an elastic gathered nonwoven web, the method comprising the steps of providing a stretchable forming surface and allowing the fibrous nonwoven gather to be in direct contact with the stretched forming surface. Forming a web into a stretched forming surface to releasably bond the fibrous non-woven gatherable web; shrinking the forming surface to gather the fibrous non-woven gatherable web; Separating the gathered fibrous non-woven gatherable web from the surface. 19. The method of claim 18 wherein the fibrous nonwoven elastic web is stretched by at least about 125 percent to about 700 percent. 20. The method of claim 18, wherein forming the fibrous non-woven gatherable web comprises forming a melt-blown ultrafine fibrous non-woven gatherable web. A method of including. 21. The method of claim 18, wherein the step of forming the fibrous non-woven gatherable web comprises a binder-free bonded ultra-fine fibrous non-woven gatherable web. A method comprising forming. 22. A method of making a gathered fibrous non-woven web having elasticity, the step of providing a non-woven elastic web forming surface capable of being stretched from a relaxed length to an extended length. Stretching the non-woven elastic web forming surface to the stretch length, and forming a fibrous non-woven gatherable web so as to directly contact the non-woven elastic web forming surface to form the non-woven elastic web forming surface. A fibrous non-woven gatherable web is releasably bonded to the surface thereof while maintaining the stretched length, and a fibrous non-woven gathered surface is formed on the non-woven elastic web to effect this releasable bond. Fibrous Non-woven Gatherable step of entwining individual fibers of web with individual fibers of fibrous non-woven elastic web forming surface and shrinking non-woven elastic web forming surface Wherein the to cover not the steps of attaching a gather the fibrous nonwoven gathered with possible web, and separating the fibrous nonwoven gathered with possible web with gathered from nonwoven elastic web forming surface. 23. The method of claim 22 wherein the step of providing the nonwoven elastic web forming surface comprises the step of forming a meltblown microfiber nonwoven elastic web. how to.