MXPA97009297A - Non-woven laminates elastomeric pla - Google Patents

Abstract

The present invention relates to a laminated material having stretchability and recovery, breathability and barrier properties, comprising: a non-woven elastomeric fabric having at least one textile fabric discontinuously joined to each side thereof with an adhesive, wherein the laminate is free of an elastomeric film, said elastomeric fabric is essentially flat when said laminate is not stretched, and the elastomeric non-woven fabric provides recovery to the laminate

Description

NON-WOVEN LAMINATES EASTOMERICOS PLANOS This application is a continuation in part of the pending application series No. 08 / 191,825 entitled "Flat Laminations of Textiles and Non Woven Elastomeric Fabrics", which was filed in the United States Patent and Trademark Office on March 3, February 1994 and which was a continuation of the now abandoned Application No. 07 / 502,098, entitled "Flat Laminations of Textiles and Non-Woven Elastic Fabrics, which was filed with the United States Patent and Trademark Office on March 30, 1990.

BACKGROUND OF THE INVENTION The present invention relates to a laminate having a stretch and recovery, a method for making such a laminate and articles made therefrom. More particularly, the present invention is directed to a laminate material of (1) a first fabric of, for example, a woven, screen or canvas material, for example a textile material together with (2) a second fabric of an elastomeric material non-woven and (3) a third fabric of, for example, a woven, screen or canvas material, for example a textile material to provide a laminate with stretch and recovery; a method for making such a laminate and articles made therefrom.

Various textile materials, such as fabrics and woven materials, can stretch, but have a relatively poor recovery, that is, they do not recover to their original size and shape after stretching. Since there is not much retraction force in recovery, these fabrics tend to lose their original size and shape.

It has been desired to provide a textile material which is not only stretchable, but also has recovery characteristics. It is also desirable to achieve such material which is stretchable and has recovery characteristics, as well as having other properties such as breathability, resistance to perforation, etc., which allow the material to be used to make garments, products for the infection control and personal care products. It is also desired to provide such a material having stretching and recovery characteristics, wherein in the unstretched state the material is not picked up, that is, it has no folded parts, for example the material is flat.

Therefore, there is still a need to provide a textile material having good stretch and recovery characteristics, but still providing a flat surface, and having desirable properties such as breathability, opacity, puncture resistance, etc.

Therefore, it is an object of the present invention to provide a textile material, having a woven, woven or canvas fabric and having stretching and recovery characteristics in all directions, limited, of course, by the inherent stretch limits of the material starting textile, whose textile material is flat, and a method for making such textile material.

It is a further object of the present invention to provide a textile material having a woven or woven fabric, and having characteristics of stretch and recovery, but without the need to include elastomeric yarn in the woven or woven structure, and without the need of elastomeric films.

It is yet another additional object of the invention to provide a textile material having a woven or woven fabric, and with good barrier properties including a resistance to perforation, insulation, filtration, opacity and liquid repellency.

It is a further object of the present invention to provide a general wardrobe, including a woven, woven or canvas fabric having stretch and recovery characteristics, which has thermal insulation properties, and a barrier to dirt, and has opacity and whose costume item has breathability.

SYNTHESIS OF THE INVENTION The above objects are achieved by the present invention which is constituted by a laminate of (1) a first fabric of a woven, woven or canvas material, (2) a second fabric of non-woven elastomeric material and (3) a third fabric made of a woven, woven or canvas material joined together in adhesive form. The fabrics when the. The non-woven elastomeric fabric is in an unstretched state, they are flat (that is, the first fabric is not folded and is not gathered). The laminated material has stretchability and recovery, breathability and barrier properties. The laminate is free of an elastomeric film and the non-woven elastomeric fabric provides recovery to the laminate. The nonwoven elastomeric fabric is preferably a melt blown elastomeric fiber fabric. These laminates are very suitable for the products for the control of the infection, the products for the personal care and for the garments.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates schematically a first embodiment of the formation of a laminate of three fabrics according to the present invention.

DEFINITIONS As used herein, the term "nonwoven fabric or fabric" means a fabric having a structure of individual fibers or threads which have been interlaced but not in an identifiable manner such as a woven fabric. Non-woven fabrics or fabrics have been formed from many processes such as, for example, meltblowing processes, spinning processes, and carded and bonded tissue processes.

The basis weight of non-woven fabrics is usually expressed in ounces of material per square yard (osy) or grams per square meter (gsm) and useful fiber diameters are usually expressed in microns (note that to convert ounces per square yard to grams per square meter multiply ounces per square yard by 33.91).

As used herein, the term "microfibers" means fibers of small diameter having an average diameter of no more than about 75 microns, for example, having an average diameter of from about 0.5 microns to about 50 microns, or more particularly, The microfibers can have an average diameter of from about 2 microns to about 40 microns. Another frequently used expression of fiber diameter is denier, which is defined by grams per 9,000 meters of a fiber. For example, the diameter of a given polypropylene fiber can be denier by squareing and multiplying the result by 0.00629, therefore, a polypropylene fiber of 15 microns has a denier of about 1.42 (152 x 0.00629 = 1.415).

As used herein the term "spunbonded fibers" refers to the small diameter fibers which are formed by extruding the melted thermoplastic material as filaments of a plurality of usually circular and thin capillary vessels of a spinner with the diameter of the extruded filaments then being rapidly reduced as indicated, for example, in U.S. Patent Nos. 4,340,563 issued to Appel et al., and U.S. Patent No. 3,692,618 issued to Dorschner et al. , U.S. Patent No. 3,802,817 issued to Matsuki et al., U.S. Patent Nos. 3,338,992 and 3,341,394 issued to Kinney, U.S. Patent No. 3,502,763 issued to Hartman, U.S. Pat. the United States of America number 3,502,538 granted to Levy, and the patent of the United States of America number 3,542,615 granted to Dobo and others. Spunbond fibers are generally non-sticky when they are deposited on a collecting surface. Spunbonded fibers are generally continuous and have diameters larger than 7 microns, more particularly, between about 10 and 20 microns.

As used herein, the term "meltblown fibers" means fibers formed by extruding a melted thermoplastic material through a plurality of capillaries, usually circular and thin as melted threads or filaments into gas currents at high temperatures. Converging velocities (for example air) which attenuate the filaments of the melted thermoplastic material to reduce its diameter, which can be to a microfiber diameter. Then, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a fabric of meltblown fibers randomly discharged. Such a process is described, for example, in United States Patent No. 3,849,241 issued to Butin, and incorporated herein by reference. The fibers formed by meltblowing are microfibers which may be continuous or discontinuous, are generally smaller than 10 microns in diameter, and are generally sticky when deposited on a collecting surface.

As used herein the term "polymer" generally includes but is not limited to homopolymers, copolymers, such as for example block, graft, random and alternating copolymers, terpolymers, et cetera and mixtures and modifications thereof. In addition, unless specifically limited otherwise, the term "polymer" will include any possible geometric configuration of the material. These configurations include, but are not limited to, isotactic, syndiotactic and random symmetries.

As used herein, the term "machine direction", or MD means the length of a fabric in the direction in which it is produced. The term "cross machine direction" or CD means the width of a fabric, for example an address generally perpendicular to the machine direction.

As used herein, the term "sewn-together" means for example, the sewing of a material according to U.S. Patent No. 4,891,957 issued to Strack et al. Or according to the United States patent of North America number 4,631,933 granted to Carey, Jr., both incorporated herein by reference.

As used herein, "ultrasonic bonding" means a process carried out, for example, by passing the fabric between a sonic horn and an anvil roll as illustrated in U.S. Patent No. 4,374,888 issued to Bornslaeger, and incorporated here by reference.

As used herein, "thermal point bonding" involves passing a fabric or fabric of fibers to be joined between a heated calender roll and an anvil roll. The calendered roll is usually, even if not always, patterned and in some way that the entire fabric is not bonded across its entire surface. As a result of this, several patterns have been developed for calendering rolls for functional as well as aesthetic reasons. An example of a pattern having points is that of Hansen Pennings, or "H &P" pattern with about 30 a hundred united area with about 200 joints / square inch as taught in U.S. Patent No. 3,855,046 issued to Hansen and Pennings. The H &P pattern has a square point or bolt of joint areas where each bolt has a side dimension of 0.965 millimeters, a separation of 1,778 millimeters between bolts, and a joint depth of 0.584 millimeters. The resulting pattern has a bound area of about 29.5 percent. Another typical point bonding pattern is the Hansen and Pennings junction pattern or expanded "EHP" that produces a 15 percent joint area with a square bolt having a side dimension of 0.94 millimeters, a bolt spacing of 2,464 millimeters and a depth of 0.991 millimeters. Another typical point union pattern designated "714" has the square point joining areas where each bolt has a side dimension of 0.023 inches, a spacing of 1,575 mm between the bolts, and a joint depth of 0.838 mm. The resulting pattern has a bound area of about 15 percent. Still another common pattern includes a diamond pattern with slightly off-centered and repetitive diamonds and a wire wave pattern looking like its name suggests, like a window grid. Typically, the percentage of bonded area varies from about 10 percent to about 30 percent of the area of the laminated fabric. As is known in the art, point bonding holds laminated layers together as well as imparting integrity to each individual layer by joining the filaments and / or fibers within each layer, unless they are pre-matched.

As used herein, the term "barrier fabric" means a fabric which is relatively impermeable. to the transmission of liquids, for example, a cloth which has a blood transfer rate of 1.0 or less according to the ASTM 22 test method.

As used herein, the term "multiple use" means a material which can be washed after use and reused at least twenty-five times without loss of structural integrity and without undue deterioration of its original properties.

As used herein, the term "pledge" means any type of non-medically oriented clothing which may be worn. This includes industrial workwear and coveralls, undergarments, pants, shirts, jackets, gloves, socks and the like.

As used herein, the term "infection control product" means medically oriented articles such as surgical gowns and drapes, face masks, head covers such as caps, surgical caps and caps, items for shoe stores such as covers of shoes, covers of boots and slippers, bandages of wounds, sterilization wraps, cleaners, garments such as lab coats, covers all, aprons and jackets, bedding for the patient, sheets for stretcher and cradle and the like.

As used herein, the term "personal care product" means diapers, training pants, absorbent underwear, incontinence garments for adults, and products for women's hygiene.

TEST METHODS Hydrohead: A measure of the liquid barrier properties of a cloth is the hydro head test. The hydro head test determines the height of water (in centimeters) that the fabric will hold before a predetermined amount of liquid passes through it. A cloth with higher hydrocarbon readings indicates that it has a greater barrier to liquid penetration than a cloth with a lower hydro head. The hydrohead test is carried out according to the standard federal test standard No. 191A, method 55.14.

Frazier Porosity: A measure of the breathability of a fabric is the Frazier Porosity which is carried out according to the Federal Test Standard 191A, Method 5450. The Frazier Porosity measures the rate of air flow through a fabric in one cubic foot of air per square foot of fabric per minute or CSM. To convert CSM to liters per square meter per minute (LSM) by multiplying by 304.8.

Resistance to Blood Penetration (RBP): The transfer of blood or resistance to the penetration of blood from a cloth is a measure of the amount of blood that enters the fabric at a particular pressure. The transfer of blood is carried out by weighing a blotter placed near the fabric before and after the test consisting of applying a pressure of one pound per square inch on atmospheric pressure (psig) to the side of the fabric towards outside the secant, whose side has blood on it. The pressure is skipped for approximately 10 seconds and removed when it reaches one pound per square inch above atmospheric pressure. The difference in the weight of the secant before and after the test in grams represents the amount of blood that has penetrated the fabric.

Bacterial Filtering Efficiency: Bacterial filtering efficiency (BFE) is a measure of the ability of a fabric to stop the passage of bacteria through it. A filtration efficiency of bacteria is generally more desired, especially in medical applications. Bacterial filtration efficiency is measured in percent according to military specification MIL-M-36954C, 4.4.1.1.1 and 4.4.1.2.

Melt Flow Rate: The melt flow rate (MFR) is a measure of the viscosity of a polymer. The melt flow rate is expressed as the weight of the material which flows from a capillary vessel of known dimensions under a specific load or cut-off rate for a measured period of time and is measured in grams / 10 minutes at 220 ° C. according to for example, the test ASTM 1238 Condition E.

Gelbo Lint Test: The Gelbo Lint Test determines the number of particles released from a fabric when it is subjected to a continuous bending and twisting motion. This is carried out according to INDA test method 160.1-92. A sample was placed in a flex chamber. When the sample is flexed, the air is pulled through the chamber at one cubic foot per minute to count in a laser particle counter. The particle counter counts the particles by size from 0.3 to 10 microns using six channels to trap the particles. The results can be reported as the total particles counted over ten consecutive thirty-second periods. The maximum concentration achieved in one of the ten account periods or as an average of the ten account periods. The test can be applied to both woven and non-woven fabrics and indicates the potential for the generation of lint from a material.

Dry spore test: The dry spore efficiency test evaluates the aerosol filtration efficiency of woven and non-woven fabrics. An aerosol is pulled through a sample of material at a rate of 1 CFM and the results are calculated after 1 minute. The aerosol is a mixture of spores of bacilli subtilis and talcum.

The water resistance impact test: This test measures the resistance of a fabric to water penetration under dynamic conditions and is carried out according to the AATCC 42 standard test. A specified volume of water is left to spray down again against the surface of a sample mounted at a 45 ° angle. The test is supported by a blotter which is weighed before and after the test. The values are recorded as the number of grams of water penetrated through the fabric. The low numbers indicate good resistance to water penetration.

Flammability: This test is designed to measure the flame resistance of materials when they are in prolonged contact (20 seconds) with the ignition source and is carried out according to NFPA-702. The test also measures the burn rate. A standardized flame is struck for 20 seconds (or until ignition) on the lower edge of a specimen of specified size mounted at a 45 degree angle. The results are recorded in seconds for the flame to extend to 5 inches.

Alcohol: This test provides an approximate index of the resistance of non-woven fabrics to penetration by alcohol and is particularly applicable when comparing several finishes on a given fabric. The effectiveness of alcohol repellent treatments or finishes is determined by placing specified percentage drops of isopropanol solutions on the surface of the sample and evaluating them after 5 minutes. The qualification is by comparison with a standard test qualifying photographs according to the INSA test method 80.9-74. 1982 revision.

DETAILED DESCRIPTION OF THE INVENTION Although the invention will be described in connection with specific and preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alterations, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

The present invention contemplates a laminated material including two textile fabrics, for example non-elastic textile fabrics such as fabrics of a woven material or a woven material, or a canvas, having characteristics of stretching and recovery, achieved by laminating the textile fabrics to a non-woven elastomeric fabric, preferably a fabric of elastomeric meltblown fibers. The laminated structure is flat, for example not collected by joining the textile fabrics and the non-woven elastomeric fabric while the non-woven elastomeric fabric is in an unstretched or very low stretch state which, upon relaxing the stretch, the textile material it does not fold.

By declaring that the fabrics are flat after lamination, it is meant that the woven fabric, the woven fabric or the canvas fabric, as part of the lamination does not fold when the elastomeric nonwoven fabric is unstretched after it is has carried out the union. The folding of a fabric fastened to a non-woven elastomeric fabric is described in U.S. Patent No. 4,720,415, the contents of which are hereby incorporated by reference in their entirety.

Therefore, the present product differs essentially from that of U.S. Patent No. 4,720,415.

According to the present invention, after bonding, the laminate can be stretched as much as the woven, woven or canvas fabric can be stretched, with the non-woven elastomeric fabric providing a recovery shrinkage force with the stretching of the stretch of the fabric. laminate.

The laminate according to the present invention includes at least three fabrics, that is, three fabrics or more than three fabrics can be included. If three fabrics are used, the non-woven elastomeric fabric can be an inner fabric of a three-fabric sandwich, with the two outer fabrics, for example, being woven or woven or canvas fabrics. In this case, the elastomeric fabric would be buried.

The non-woven elastomeric fabric can be, for example, a spin-bonded fabric or a melt-blown fiber fabric. Desirably, the non-woven elastomeric fabric is made of meltblown elastomeric fibers. Various known materials for forming meltblown elastomeric fibers, such as copolyester esters; copolymers of ethylene and at least one vinyl monomer (for example ethylene vinyl acetate); the ABA 'block copolymers, wherein A and A' may be the same or different end blocks and each is an end block of thermoplastic polymer or segment which contains a styrenic group such as polystyrene or polystyrene homologs, and B is a block medium of elastomeric polymer or segment, segmented block copolymers, of two 'ternary segments, having the formula AB; and a urethane polymer (for example polyurethane or a urethane copolymer) can be used in the present invention for the non-woven elastomeric fabric. "/ Another suitable material is a polyester polyamide block copolymer having the general formula: HO- [C-PA-C-O-PE-0-] n-H h h Where n is a positive integer, PA represents a polyamide polymer segment and PE represents a polyether polymer segment. In particular, the polyether block amide copolymer has a melting point of from about 150 ° C to about 170 ° C, as measured in accordance with ASTM D-789; a melt index of from about 6 grams per 10 minutes to about 25 grams per 10 minutes, as measured in accordance with ASTM D-1238, condition Q (235 C / lKg load); a flexural modulus of flexure from about 20 Mpa to about 200 Mpa, as measured in accordance with ASTM D-790; a tensile strength at break from about 29 Mpa to about 33 Mpa as measured in accordance with ASTM D-638 and an ultimate elongation at break from about 500 percent to about 700 percent as it is measured by the ASTM D-638 standard. A particular embodiment of the polyether block amide copolymer has a melting point of about 152 ° C as measured according to ASTM D-789; a melt index of about 7 grams per 10 minutes, as measured in accordance with ASTM D-1238, condition Q (235 C / lKg load); a modulus of elasticity in flexion of about 29.50 MPa, as measured in accordance with ASTM D-790; a tensile strength at breaking of around 29 Mpa, a measure in accordance with ASTM D-639; and an elongation at break of about 650 percent as measured in accordance with ASTM D-638. Such materials are available in various classes under the trade designation PEBAX® from Atochem Inc. Polymers Division (RILSAN®), of Glen Rock, New Jersey. Examples of the use of such polymers can be found in U.S. Patent Nos. 4,724,184, 4,820,572 and 4,923,742 incorporated herein by reference, issued to Killian et al.

Polymers composed of a tetrablock copolymer A-B-A-B can also be used in the practice of this invention. Such polymers are dispersed in the patent of the United States of America number 5,332,613 granted to Taylor and others. In such polymers, A is a block of thermoplastic polymer and B is a hydrogenated isoprene monomer unit to essentially a monomer unit of poly (ethylene-propylene). An example of such a tetrablock copolymer is a styrene-poly (ethylene-propylene) -styrene-poly (ethylene-propylene) block copolymer or an SEPSEP elastomeric block copolymer available from the Shell Chemical Company of Houston Texas., Jsajo the designation of KRATON® G-1657 trade. KRATON block copolymers are available in several different formulas, a number of which are identified as US Pat. Nos. 4,663,220 and 5,304,599, and incorporated herein by reference.

Other exemplary elastomeric materials which may be used include elastomeric polyurethane materials such as, for example, those available under the trademark ESTAÑE® of B. F. Goodrich & Company or MORTHANE® by Morton Thiokol Corporation, and elastomeric materials such as, for example, those known as ARNITEL previously available from Akzo Plastics of Arnhem, The Netherlands and now available from DSM of Sittard, The Netherlands, or those known as ® which are available from E. I. DuPont of HYTREL Nemours of Wilmington, Delaware.

The specific elastomeric materials are only illustrative and not limiting. As for the various elastomeric polymers that can be used and, in addition, the techniques for forming the meltblown elastomeric fibers and the non-woven fabrics of these meltblown fibers, attention is directed to the specific meltblown materials of U.S. Patent No. 4,720,415 and 4,801,482; and U.S. Patent No. 4,707,398 issued to Boggs and U.S. Patent No. 4,741,949 to Morman and others whose contents are hereby incorporated by reference in their entirety. Various other elastomeric materials may be formed in meltblown elastomeric fabrics and each falls within the contemplation of the non-woven elastomeric fabrics of the present invention.

The non-woven elastomeric fabric useful in the present invention may be a bonded or unbonded material. Specifically, the bonding of the non-woven elastomeric material can improve the abrasion resistance. Such bonding can be achieved thermally, ultrasonically or by stitching, for example, the non-woven elastomeric fabric can be thermally bonded.

Stretch recovery of the non-woven elastomeric fabric is important in relation to the present invention since the degree of recovery of the non-woven elastomeric fabric will control the degree of recovery in the laminate. It is desirable that the non-woven elastomeric fabric has an omnidirectional stretch and recovery so as to deliver strength recovery to any fabric that is used. Therefore, by using a non-woven elastomeric fabric having an omnidirectional stretch and recovery, if the non-woven fabric of the laminate is stretched in the machine direction (MD), then the laminate will have a force recovery in the machine direction. If the fabric is stretched in all directions, then the laminate will have a recovery of strength in all directions.

A unique aspect of the woven materials is that they can be stretched largely in the deviation, for example at 45 ° from the machine direction (MD) or the transverse direction (CD). Using a non-woven elastomeric fabric having an omnidirectional stretch and recovery, recovery is also provided in the bias direction.

The non-woven elastomeric material is preferably a melt blowing material. The fibers in the non-woven elastomeric fabric illustratively vary from 0.5 to 100 microns in diameter. The barrier properties in the finished laminate, for example, increased opacity and / or insulation and / or protection against dirt and / or liquid repellency, are improved by the use of finer fibers in the range of 0.5. -20 mieras.

The non-woven elastomeric fabric can be an elastomeric non-woven composite fabric. Illustratively, such composite fabric may be made from a mixture of two or more different fibers or from a mixture of fibers and particulates. Such mixtures may be formed by adding fibers and / or particulates to the gas stream in which the elastomeric meltblown fibers are carried such that intimate entangled mixing of the elastomeric meltblown fibers and other materials occurs prior to the collection of the meltblown fibers on a collection device to form a coherent web of randomly dispersed meltblown fibers and other materials, such as is described in U.S. Patent Nos. 4,100,324 and 4,803,117 , the contents of which are incorporated herein by reference in their entirety. Useful materials which can be used in such elastomeric non-woven composite fabrics include, for example, wood pulp fibers, short length fibers from natural and synthetic sources, for example, cotton, wool, asbestos, rayon, polyester, polyamide and the like, non-elastic meltblown fibers, and particulates such as, for example, activated carbon particulates and hydrocolloid particulates (hydrogel) commonly referred to as superabsorbents. Other types of non-woven elastomer composite fabrics can be used. For example, a hydraulically entangled non-woven elastomeric composite fabric can be used as described in U.S. Patent No. 4,879,170 issued to Radwanski et al. And in U.S. Patent Application No. 07 / 170,209 granted to Raswanski and others whose contents are hereby incorporated by reference in their entirety.

The basis weight of the non-woven elastomeric fabric can illustratively range from 6.8 to 204 grams per square meter. The basis weight is selected to provide the desired rolling properties, including the recovery and barrier properties. The most preferred basis weight for the non-woven elastomeric fabric is from 10.2 to 102 grams per square meter. As previously indicated, the non-woven elastomeric fabric should be attached to a woven fabric or a woven fabric or a canvas fabric, for example, a non-elastic textile fabric, according to the present invention. The basis weight of the non-elastomeric non-woven fabric can illustratively range from 0.20 to 6.0 osy. These woven fabrics, woven fabrics and canvas fabrics are known in the art. Conventional fabrics, for example textile fabrics, such as the non-elastic textile fabric can be used for the present invention. A particularly suitable type of materials, for example, nylon tricot fabric. Another fabric useful in the practice of this invention and having a higher heat resistance than nylon is polyester fabric. Even more particularly, the polyester fabric fabric incorporating about 4% carbon fibers for static reduction functions works well in the practice of this invention. The continuous fiber material is preferred because it tends to produce less lint than other materials. Woven fabrics, woven fabrics and canvas fabrics can be formed as is conventionally done.

Woven fabrics will generally have good stretch but a relatively poor recovery. Since there is not much retraction force in recovery, these woven fabrics tend to lose their shape. However, a laminate according to the present invention, using a non-woven elastomeric fabric as discussed above, imparts recovery to the fabric. In addition, particularly when an elastic melt blow is used for the non-woven elastomeric fabric, the laminate has a unique z-direction impact and puncture resistance. further, by using the non-woven elastomeric fabric, the durability of the woven fabric is improved because the yarns are fixed on the elastomeric surface, for example, the elastomeric melt blowing surface, and are not subjected to the same level of abrasion give thread by thread and the tensions that the free cloth structure will experience. In addition, the backed or laminated fabrics with the non-woven elastomeric fabric, eg, an elastomeric meltblown fabric, are bagged and made resistant to run because the yarns are immobilized on the elastomeric meltblown surface. Therefore, the use of the non-woven elastomeric fabric, particularly an elastomeric meltblown fabric, provides recovery force to prevent bagging and provides a puncture resistance, toughness, resistance to liquid penetration and leakage of water. particle. * In addition to the use of a woven Jtela in combination with the non-woven elastomeric fabric, according to the present invention, a woven or canvas fabric can be used. Even though canvas or woven fabrics have more dimensional stability than fabrics, especially in the machine and transverse directions, the recovery force is added to these materials to the extent that they stretch. Of particular interest is the bias stretch of for example woven fabrics. The laminate of the present invention using a non-woven elastomeric fabric together with the non-woven fabric provides a stretch recovery in the deflection.

As with fabrics, laid canvas yarns or fabrics are stabilized in their original structure, reducing yarn wear against yarn, when woven or canvas fabrics are laminated with elastomeric non-woven fabric according to the present invention. . The stabilization of the placed canvas fabrics is particularly useful, since the non-woven canvases have poor dimensional stability to begin with. As with woven laminates, the Z-direction perforation and impact resistance of the fabric and canvas laminate are improved in the structure of the present invention compared to the use of a canvas or woven fabric by itself.

The non-woven elastomeric fabric can be laminated to the woven fabric, weft or canvas material using an adhesive. The most important factor is that the non-woven elastomeric fabric is not stretched during lamination; or alternatively that any stretching or non-woven elastomeric fabric during bonding is sufficiently short that when the elastomeric non-woven fabric relaxes to its unstretched state after bonding, there is no folding or puckering of the woven fabric.

Various means of joining the elastomeric fabric to another fabric are described, for example, in U.S. Patent No. 4,720,415, the contents of which have been previously incorporated by reference in their entirety.

An adhesive can be pre-applied to the non-woven elastomeric fabric and / or the textile material; Such adhesive can be activated by heat to achieve. l'a lamination. In addition, aqueous adhesives, or solvent-based additives, known in the art can be used. An adhesive web can be incorporated between the textile material and the non-woven elastomeric fabric, to provide the. Union. ' An important factor for the adhesive is that it does not interfere with the elasticity (eg recovery) of the laminate. For this reason as well as to allow air permeability the adhesive must be decipient through the laminate. Therefore, the application of the adhesive should be done "in a manner known in the art as long as the adhesive is discontinued. Such application means include rotogravure, spot engraving, flexographic, grid printing, ink jet printing and melt blowing.

The adhesive must be one crosslinked and preferably a self-adhesive and durable adhesive. Examples of such adhesives are described in United States Patent Application No. 07 / 995,468 (the application '468) incorporated herein by reference to Faas and assigned to the same assignee as this application and may be in the form of a randomly spread network of thermofused filaments and / or adhesive fibers. The adhesive material may be a coating of any conventional hot-melt or commercially available adhesive such as, for example, hot-melt adhesives which may be based on blends of polyolefins, adhesive resins, triblocks and waxes. The adhesive can typically be used in an amount between about 3 and 20 grams per square meter or more particularly about 5 grams per square meter.

A good coating for the practice of this invention is that of the United States patent of North America 5,149,741, incorporated herein by reference and granted to Alper et al. And assigned to Findley Adhesives, Inc., of Wauwatosa, Wisconsin. The coating is an adhesive which comprises about 15 to 40 parts of styrene-isoprene-styrene block copolymer wherein the styrene content of the copolymer is from 25 to 50% by weight, about 40 to 70 parts of the resin compatible adhesive such as, for example, the pentaerythritol esters, about 5 to 30 parts of naphthenic parainic oil and 0.1 to 2 parts, by weight, of a phosphite antioxidant, hindered phenolic antioxidant and a stabilizer, wherein the adhesive has a melt viscosity of not more than 6000cP at 325 ° F.

Another example of an acceptable adhesive is that available from Advanced Resin Technology, Inc., of Manchester N.H. which is commercially available under the designation of ® ® brand Bondstar. The Bondstar RS-10178 adhesive, for example, is a thermoplastic urethane adhesive which can be supplied from conventional hot-melt equipment at temperatures up to about 204 ° C.

Illustratively, the bonding temperature may vary from room temperature to 482 ° C, the optimum temperature range depending on the fabrics and the adhesive used. Liquid adhesives can allow ambient bonding temperatures. High bonding temperatures are needed to melt the fabrics together using a thermoplastic adhesive / web, with actual temperatures depending on the adhesive being used and the melting temperatures of the fabrics involved.

Figure 1 shows one embodiment of the formation of a laminate of three fabrics according to the present invention using adhesive to provide the bond for lamination.

In particular, the reference characters 14-16 represent three fabrics to be laminated. Both of the fabrics 14 to 16 are a textile fabric while the fabric 15 is a non-woven elastomeric fabric. The reference character 17 represents an adhesive applicator, known in the art, which deposits an adhesive on both top and bottom surfaces of the middle fabric 15. After the adhesive has been applied, the fabric 15 is combined with the fabrics 14 and 16 are passed between the joining rollers 18 and 19, where the joint occurs. The adhesive can be any suitable adhesive (liquid or thermoplastic) and can include solvent or aqueous based adhesives, as well as meltable coatings. The adhesive must be applied in a pattern, for example discontinuously.

As can be seen from the foregoing, any number of fabrics can be laminated, to form a laminate according to the present invention and either the textile fabric or the non-woven elastomeric fabric or both can be exposed in the laminate.

The laminates of this invention may have topical treatments also applied to them for more specialized functions. Such topical treatments and their methods of application are known in the art and include, for example, alcohol repellency treatments, antistatic treatments and the like, applied by spraying, embedding, et cetera. Fluorocarbon chemicals to improve chemical repellency which may be, for example, any of those taught in US Pat. No. 5,178,931, incorporated herein by reference may be added to the fabric. An example of such a topical treatment ® is the application of the Zelec antistatic, (available from E.I. duPont of Wilmington, Delaware). A preferred repellent treatment is produced by Synfin Industries of North Wales, Pennsylvania, as a proprietary treatment chemist. It is important that any treatments applied to the material be low in formaldehyde or other volatile materials since these will be in close contact with people during most applications. The laminate can also have conductive carbon fibers incorporated there of up to about 10% by weight, as a measure of static reduction to fill the static decay requirements under Federal Test 101C method 4046.

Fabrics for infection control applications, for example, as a surgical gown, must have good liquid barrier properties in order to protect medical personnel from contact with fluids of the patient's body but must still be respirable in order to to allow the perspiration of the user to pass through the fabric as if to remain comfortable. The fabric must also be strong enough to carry out the desired function in the proper environment but still be soft, stretchable and fall for user comfort and to avoid restricting the user's range of motion.

It is also important in many applications of the fabrics, for example as garments, that the finished product be as lightweight as possible but still carry out its desired function, a lighter garment carrying out the same function as a heavier garment will be more comfortable for the user and probably less expensive to manufacture since less raw material will be needed for its production.

A light weight soft fabric having liquid barrier properties, good strength and high vapor transmission can be very useful in a wide range of applications.

Yet another useful property of the fabric of this invention is that it can be reused a number of times before being discarded. Such a possibility of reuse helps reduce the waste costs, and environmental problems when the fabric is used as a surgical gown, for example, such materials contaminated with body fluids require specialized disposal procedures. By reducing the volume of material to be disposed of from single-use materials, surgical garments made from the fabric of this invention can contribute to a reduction in national medical care expenses.

When the laminated material according to the present invention is used as a garment, the garment has thermal insulation and a barrier to dirt to protect, while having breathability for comfort. In addition, clothing made of the laminate material of the present invention has opacity that is not otherwise achieved in lightweight fabrics.

Below is described a laminate according to the practice of this invention as well as the commercially available materials currently used for surgical gowns. Also set forth in Table 1 for each of these examples are various properties of the materials as measured according to the tests described above.

® Example 1 - The used ComPel fabric was part of a reusable multipurpose chemical gown and was made from a 100% woven polyester yarn tightly. ComPel fabric does not stretch or recover. The tested material had a coating and was available from Standard Textile Company of Cincinnati, Ohio ® 45222. The tested ComPel fabric was coated with a repellent ® known as SYLGARD from Dow Corning. The manufacturer ® of ComPel fabric claims that it can be washed and reused a hundred times. The test results are on the unwashed material.

Example 2 - This material is a spin-bonded / melt-bonded / spunbonded laminate or SMS available from Kimberly-Clark Corporation of Neenah, Wisconsin as a disposable surgical gown material under the brand designation ® ® Evolution III. The SMS fabric of the Evolution gown does not stretch or recover. The spunbonded layers each have a basis weight of 18.5 grams per square meter and the meltblown layer has a basis weight of 17 grams per square meter. The spunbond layers were made of polypropylene manufactured by Exxon Chemical Company of Houston, Texas, under the trade designation PD 9355. These layers include minor amounts of pigments. The meltblown layer was also made of Exxon polypropylene. The material was designated PD-3495G. This layer also included a smaller amount of pigment. The fabric was thermally bonded. The fabric was treated topically with a chemical repellent mixture including DuPont 7700 repellent, antistatic ® Zelec and hexanol.

Example 3 - This material is a laminate made in accordance with this invention. This was comprised of an elastic meltblown fabric of 51 grams per square meter adhesively laminated to a continuous filament nylon S850 tricot fabric with 18 loops per inch on both sides. The meltblown fabric is available under the trade designation Demique fabric from Kimberly-Clark Corporation and was composed of elastomeric fibers made of Armitel EM400 polymer from DSM. The adhesive used was Bondstar RS-10178 urethane adhesive ® applied in an amount of about 5 grams per square meter on each side of the elastic fabric using a spot engraving print. The laminate was treated with a repellent treatment from Synfin Industries, North Wales, Pennsylvania. This material has been washed 50 times without delamination and therefore is a reusable or multipurpose material. The test results are on unwashed materials.

TABLE 1 EXAMPLE PROOF 1 2 3 Transfer Blood (percent) 0.21 1.0 0.75 Hydrohead (centimeters) > 100 53 33 Impact Penetration (gr.) < 1.0 < 1.0 < 1.0 Alcohol (visual rating 1-5) 5 5 5 BFE (percent) 53 81 84 Dry spore (# of part for 1000) - 1.4 0.4 Hilacha Gelvo (average of 10 periods of 30 seconds) 10 microns 16 17 8 0.5 microns 3700 3460 360 Flammability (seconds) Class 1 Class 1 Class 1 Frazier Porosity (ft3 / minute / ft2) 1 41 57 As seen from the previous examples, the laminate material of the present invention, including the non-woven elastomeric fabric, provides improved properties compared to commercially available materials. The laminate of this invention has a low blood transfer rate coupled with a good hydro head and a very high breathability (Frazier porosity). The particulate filtering is also very good and the generation of lint in the order of a magnitude better than the competitive fabrics in the smallest particle size, due at least in part, the inventors believe, the fact that the fibers of the textile fabrics of this invention are preferably continuous fibers. This combination of properties makes this laminate an excellent candidate for protection but breathable service requirements.

Therefore, the objectives as discussed above are achieved by the present invention. Specifically, the laminate textiles present have a recovery force in all directions, even though the degree of stretching is limited by the inherent stretching of the starting fabric (fabric or screen or canvas). In addition, the non-woven elastomeric fabric component, particularly when such a component is a meltblown elastomeric fiber fabric, squeezes the textile structure providing barrier properties and closing the holes between the fabric yarns, for example woven or woven. These barrier properties include puncture resistance, insulation, filtering, opacity, and liquid repellency. Therefore according to the present invention the elastomeric component can be buried in the textile structure (for example put in the form of a sandwich between two fabrics of textile material such as a woven material), whereby any undesirable sensation of the elastomeric component can be avoided by a simple processing technique. In this regard, with the conventional structures, using the spandex yarns, an expansive core wrapping process is carried out to overcome the poor coverage and tactile aesthetics of such yarn; such a core wrapping process is unnecessary in the present invention.

In addition, the present invention can provide a textile material having stretch and recovery characteristics, as well as other properties as discussed above, in a relatively simple and inexpensive process. Such a process according to the invention is clearly preferable to the present technique for forming textile fabrics, incorporating rubber or spandex threads within the woven or woven structure. Such Spandex or rubber yarns are very difficult to process on the weaving or screening equipment due to their stretchability and relatively high coefficient of friction, and the relatively high costs of the equipment to establish them.

The inclusion of less than about 10% by weight of the carbon fibers in the fabrics of this invention ensures that the fabric will meet the current conductivity requirements of the Federal Test 101C method 4046.

Thus, the laminate material of the present invention, including the non-woven elastomeric fabric and the textile fabrics, achieves the advantages of a textile fabric while also achieving improved properties due to the non-woven elastomeric fabric.

The laminate according to the present invention has an improved breathability, compared to the textile laminates including an elastic film. Laminates according to the present invention can be produced in lower basis weights than woven or woven containing elastic threads, due to the denier of the elastic threads. In addition, the laminates according to the present invention can be produced at a lower cost than woven or woven fabrics containing elastic yarns due to the processing difficulties of the elastic yarns. The processing of the laminate according to the present invention provides techniques for adding elasticity to the available textiles, efficiently and at a relatively low cost.

Having thus described the invention in detail it should be appreciated that changes and modifications can be made to the present invention without departing from the spirit and scope of the present claims.

Claims (18)

R E I V I ND I C A C I O N S

1. A laminated material having stretchability and recovery, breathability and barrier properties, comprising: a non-woven elastomeric fabric having at least one fabric of textile fabric attached discontinuously to each side thereof with an adhesive, wherein the laminate is free of an elastomeric film, said elastomeric fabric is essentially planar when said laminate is unstretched, and the elastomeric non-woven fabric provides recovery to the laminate.

2. A laminated material, as claimed in clause 1, characterized in that the laminate further comprises a topical repellent.

3. A laminated material, as claimed in clause 2, characterized in that said textiles are independently selected from the group consisting of woven, woven and canvas materials.

4. A laminated material, as claimed in clause 3, characterized in that said textile is a fabric and the woven material is stretchable but has essentially no recovery, the meltblown elastomeric fiber fabric provides recovery for the laminate.

5. A laminated material, as claimed in clause 3, characterized in that said non-woven elastomeric fabric is a meltblown fiber fabric made of a material selected from the group consisting of elastic ester copolyethers; elastic urethane polymers; copolymers of ethylene and at least one vinyl monomer; polyether polyamide block copolymers, block copolymers A-B, block copolymers A-B-A ', tetrablock copolymers A-B-A-B and polyester elastomeric materials.

6. A laminated material, as claimed in clause 3, characterized in that said textiles comprise carbon fibers in an amount of less than about 10% by weight.

7. A laminated material, as claimed in clause 2, characterized in that said laminate is a multipurpose material.

8. A laminated material, as claimed in clause 2, characterized in that the range of meltblown elastomeric fibers is 0.5 to 20 microns in diameter.

9. A laminated material, as claimed in clause 2, characterized in that the non-woven elastomeric fabric has a basis weight of 0.20 to 6.0 ounces per square yard.

10. A laminated material, as claimed in clause 2, characterized in that the textile fabrics are made of continuous fibers.

11. A laminated material, as claimed in clause 2, characterized in that said laminate has a porosity greater than 50 p.sup.3 / minute / ft.sup.2 and a blood transfer of less than 1.0%.

12. A laminated material, as claimed in clause 1, characterized in that said adhesive is a durable and self-degrading adhesive.

13. A laminated material, as claimed in clause 1, characterized in that it is present in an article selected from the group consisting of garments, products for infection control and personal care products.

14. A laminated material, as claimed in clause 13, characterized in that said article is an infection control product and said infection control product is a surgical gown.

15. A laminated material, as claimed in clause 13, characterized in that said article is an infection control product and said infection control product is a mask for the face.

16. A laminated material, as claimed in clause 13, characterized in that said article is an infection control product and said infection control product is a sterilization wrap.

17. A laminated, washable multipurpose material having stretchability and recovery, breathability and barrier properties comprising: an elastomeric meltblown polyester fabric having at least one fabric of a continuous filament polyester fabric also comprising about 4% by weight of carbon fibersadhesively and discontinuously attached to each side thereof to form a laminate, wherein the laminate is free of an elastomeric film, said elastomeric fabric is essentially flat when said laminate is unstretched, and the elastomeric non-woven fabric provides recovery to the elastomeric fabric. laminate; Y a low formaldehyde repellent material applied topically on said laminate.

18. A process for forming a laminate having stretch and recovery, and having a flat surface when the laminate is in the unstretched state, the laminate being free of an elastomeric film, comprising the steps of: providing a first fabric of a material selected from the group consisting of a fabric material, a woven material and a canvas material, close to the non-woven elastomeric fabric; Y joining the first fabric to the non-woven elastomeric fabric so that, when the first fabric and the attached non-woven elastomeric fabric are not stretched, the first fabric is essentially flat, the joining being carried out without an elastomeric film so that the Laminated material is free of an elastomeric film. SUMMARY A laminate material having stretchability and recovery, breathability and barrier properties is provided and is made of a non-woven elastomeric fabric I having at least one textile fabric bonded adhesively and discontinuously on each side thereof. The laminate is free of an elastomeric fabric, the elastomeric fabric is essentially flat when the laminate is unstretched, and the non-woven elastomeric fabric provides recovery to the laminate. The non-woven elastomeric fabric is preferably a fabric of. Meltblown elastomeric fibers and other fabrics can be woven, woven or canvased materials - These Tampers are very suitable- for infection control products, personal care products and garments.