CA2117684A1 - Soft stretchable composite fabric - Google Patents
Soft stretchable composite fabricInfo
- Publication number
- CA2117684A1 CA2117684A1 CA002117684A CA2117684A CA2117684A1 CA 2117684 A1 CA2117684 A1 CA 2117684A1 CA 002117684 A CA002117684 A CA 002117684A CA 2117684 A CA2117684 A CA 2117684A CA 2117684 A1 CA2117684 A1 CA 2117684A1
- Authority
- CA
- Canada
- Prior art keywords
- composite material
- porous film
- transverse direction
- fabric
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000004744 fabric Substances 0.000 title claims abstract description 53
- 239000002131 composite material Substances 0.000 title claims abstract description 49
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 38
- 238000006073 displacement reaction Methods 0.000 claims abstract description 7
- 229920000295 expanded polytetrafluoroethylene Polymers 0.000 claims description 17
- 239000004814 polyurethane Substances 0.000 claims description 14
- 229920002635 polyurethane Polymers 0.000 claims description 14
- 229920000642 polymer Polymers 0.000 claims description 13
- 229920001477 hydrophilic polymer Polymers 0.000 claims 6
- 230000004888 barrier function Effects 0.000 abstract description 7
- 239000000463 material Substances 0.000 description 20
- 238000000034 method Methods 0.000 description 12
- 238000012360 testing method Methods 0.000 description 12
- 239000000853 adhesive Substances 0.000 description 11
- 230000001070 adhesive effect Effects 0.000 description 11
- 230000035699 permeability Effects 0.000 description 11
- 239000011148 porous material Substances 0.000 description 9
- 238000011084 recovery Methods 0.000 description 8
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 7
- 239000004810 polytetrafluoroethylene Substances 0.000 description 7
- 229920000742 Cotton Polymers 0.000 description 6
- 238000003475 lamination Methods 0.000 description 6
- 239000012528 membrane Substances 0.000 description 6
- -1 polytetrafluoroethylene Polymers 0.000 description 6
- 238000000576 coating method Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000003490 calendering Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 239000012943 hotmelt Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000004952 Polyamide Substances 0.000 description 2
- 230000002730 additional effect Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 229920001973 fluoroelastomer Polymers 0.000 description 2
- 238000007646 gravure printing Methods 0.000 description 2
- 229920002647 polyamide Polymers 0.000 description 2
- SCVFZCLFOSHCOH-UHFFFAOYSA-M potassium acetate Chemical compound [K+].CC([O-])=O SCVFZCLFOSHCOH-UHFFFAOYSA-M 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229920002994 synthetic fiber Polymers 0.000 description 2
- 239000012209 synthetic fiber Substances 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 102100024133 Coiled-coil domain-containing protein 50 Human genes 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 101000910772 Homo sapiens Coiled-coil domain-containing protein 50 Proteins 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000011549 displacement method Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 229920002313 fluoropolymer Polymers 0.000 description 1
- 239000004811 fluoropolymer Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 235000011056 potassium acetate Nutrition 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 239000004634 thermosetting polymer Substances 0.000 description 1
- 230000004584 weight gain Effects 0.000 description 1
- 235000019786 weight gain Nutrition 0.000 description 1
- 210000002268 wool Anatomy 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A41—WEARING APPAREL
- A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A41D31/00—Materials specially adapted for outerwear
- A41D31/04—Materials specially adapted for outerwear characterised by special function or use
- A41D31/10—Impermeable to liquids, e.g. waterproof; Liquid-repellent
- A41D31/102—Waterproof and breathable
-
- A—HUMAN NECESSITIES
- A41—WEARING APPAREL
- A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A41D31/00—Materials specially adapted for outerwear
- A41D31/04—Materials specially adapted for outerwear characterised by special function or use
- A41D31/12—Hygroscopic; Water retaining
- A41D31/125—Moisture handling or wicking function through layered materials
-
- A—HUMAN NECESSITIES
- A41—WEARING APPAREL
- A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A41D31/00—Materials specially adapted for outerwear
- A41D31/04—Materials specially adapted for outerwear characterised by special function or use
- A41D31/14—Air permeable, i.e. capable of being penetrated by gases
- A41D31/145—Air permeable, i.e. capable of being penetrated by gases using layered materials
-
- A—HUMAN NECESSITIES
- A41—WEARING APPAREL
- A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A41D31/00—Materials specially adapted for outerwear
- A41D31/04—Materials specially adapted for outerwear characterised by special function or use
- A41D31/18—Elastic
- A41D31/185—Elastic using layered materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/12—Layered products comprising a layer of synthetic resin next to a fibrous or filamentary layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
- B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
- B32B5/245—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it being a foam layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2266/00—Composition of foam
- B32B2266/02—Organic
- B32B2266/0214—Materials belonging to B32B27/00
- B32B2266/025—Polyolefin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/50—Properties of the layers or laminate having particular mechanical properties
- B32B2307/514—Oriented
- B32B2307/516—Oriented mono-axially
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/718—Weight, e.g. weight per square meter
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/726—Permeability to liquids, absorption
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/726—Permeability to liquids, absorption
- B32B2307/7265—Non-permeable
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/728—Hydrophilic
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2437/00—Clothing
Abstract
A stretchable water vapor permeable composite material comprisinga layer of porous film adhesively laminated to a layer of fabric;
said porous film and said fabric having lower tensile modulus in the transverse direction than in the machine direction and having their axes of lower tensile modulus in parallel alignement, and each having, at 25 % extension in the transverse direction, a force to displacement (F/D) ratio per inch width less than 3.5; and said composite material having, at 25 % extension in the trasverse direction, an F/D ratio per 2.54 cm width less than 9Ø This composite fabric has barrier properties such as windproofness and water-penetration resistance and is suitable for use in many types of lightweight or close-fitting garments.
said porous film and said fabric having lower tensile modulus in the transverse direction than in the machine direction and having their axes of lower tensile modulus in parallel alignement, and each having, at 25 % extension in the transverse direction, a force to displacement (F/D) ratio per inch width less than 3.5; and said composite material having, at 25 % extension in the trasverse direction, an F/D ratio per 2.54 cm width less than 9Ø This composite fabric has barrier properties such as windproofness and water-penetration resistance and is suitable for use in many types of lightweight or close-fitting garments.
Description
W093t21013 ~A ~ 4 -1- PCl/US92/0380~ ~
TITLE OF THE INVENTION
SOFT STRETCHABLE COMPOSITE FABRIC
FIELD OF THE INVENT10~1 This invention is related to stretchable layered composite fabrics, more particularly, to layered composite fabrics which provide barrier properties with water vapor permeability.
;~ BACKGROUND OF THE INVENTION
..
Knitted fabrics are generally softer, more drapeable, offer less resistance to stretching and can be stretched without damage further than woven fabrics. These comfort related properties are very important considerations in the design and manufacture of many types of lightweight or close-fitting garments.
~ , Lightweight knitted fabrics have a relatively open `-construction, exhibit high air permeability and, consequently, haYe virtually no barrier properties such as windproofness or thermal insulation qualities. This severely limits the outdoor applications in colder weather without additional outer layers.
It is very desirable to enhance the barrier properties of the lightweight knitted fabrics while continuing to provide comfort related properties such as softness, drapeability, stretchability, stretch-recovery and water-vapor-permeability.
SUMMARY OF THE IN~/ENTION
This invention provides soft drapeable stretchable water-vapor-permeable layered composite materials having low tensile modulus in the transverse direction and having functional properties such as windproofnesst water-vapor-permeabilityt weather resistance or waterproofness.
8y tensile modulus" it is meant the resistance of a material to be stretched or elongated. It is expressed herein in terms of w 0 93/21013 C ~ 2 i I /6~ ` -2- PCT/US92/0380X
the force (F) required to stretch or elongate the material a specified distance (D).
By "windproofness" it is meant a low rate of permeability of air through the material. It is expressed herein in term~ of the s volume of air (cm3) passing through a given area (cm2) in a given time (min) under a given pressure drop (mm water pressure).
The force to displacement (F/D) ratio as used herein is the ratio obtained by dividing the tensile force ~expressed in Newtons) to stretch a 2.54 cm wide specimen to 1.25 times its original o length (25% extension) by the displacement (expressed in centimeters) to reach 25% extension.
Transverse direction is used herein to indicate the direction in the plane of manufacture perpendicular to the machine direction (direction of manufacture). The materials of the layers described herein are considered to be planar, defined by their length (machine direction) and width (transverse direction).
The composite material of the invention can comprise a layer of porous film adhesively laminated to a 7ayer of fabric; the - porous film and the fabric each having, at 25% extension in the transverse direction, an F/D ratio per 2.54 cm width less than 3.5;
and the composite material having an F/D ratio less than 9Ø
Another embodiment of the composite material of the invention can comprise a layer of porous film to each side of which is adhesively laminated a layer of fabric; the porous film and the fabric each having, at 25X extension in the transverse direction, an f/D ratio less than 3.5; and the composite material havin~, at 25% extension in the transverse direction, an F/D ratio less than 9Ø
By "porous" is meant that the film has pores or voids from one side to the other.
To enhance barrier properties such as windproofness or waterproofness the porous film of the embodiments above may be - coated with a continuous substantially air-impermeable layer of hydr~Rhilic water vapor-permeable polymer, e.g. a polyurethane, which prevents passage of liquid water through it, but has high water-vapor-permeability.
The stretchtble water-vapor-permeable layered composite material of the invention has excellent drape characteristics and W093/21013 ~A ~ i 1 I h~4 3 PCr/US92/03XOX
can be substantially stretched in the transverse direction by application of very low forces without loss of important functional characteristics such as windproofness, water-vapor-permeability, weather resistance or waterproofness.
s To enhance these properties, the axes of lower tensile modulus of the layers of the composite are aligned in substantially parallel orientation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The layered composite materials of the invention are lo engineered to enhance softness, drape, stretchability and stretch-recovery, and to minimize resistance to stretching in the transverse direction, first through selection of component materials, each preferably having high softness, drape, stretchability and stretch-recovery, and each having lower tensile modulus in the transverse direction than in the machine direction;
and secondly, in contrast to conventional practices, by aligning the axis of lowest tensile modulus of each layer in the same direction with respect to its neighboring layers. Thus, it can be seen that an important element in the construction of the layered composite material of the invention is the relative orientation of the tensile properties of each layer.
A preferred embodiment of the stretchable water-vapor-- permeable composite material of the invention comprises a layer of porous film adhesively laminated to a layer of fabric. Another preferred embodiment of the invention comprises a layer of porous film to each side of which is adhesively laminated a layer of fabric.
~he porous film may have a pore volume in the range 40 - 95 percent, preferably 60 - 95 percent; a mean pore s~ze smaller than ~- 30 about 2 m~crometers, preferàbly smaller than 1 ~icrometer; air ;~ permeability less than about 91 cubic centimeters/minute/square ~; centimeter at a pressure drop of 12.7 millimeters water; lower tensile modulus in the transverse direction than in the machine direction, and an F/D ratio, at 25% extension in the transverse 3s direction, less than 3.5. The porous film may be a membrane, mesh, WO 93/21013 C A ~ I 1 / 6 ~ 4 PCl/US92/0380X
or nonwoven web selected from, but not limited to the group:
polyolefin, polyamide, polyester, polyurethane, fluoropolymer, and the like. Such films are known in the art and are commercially available. The preferred film is porous polytetrafluoroethylene, more preferably, porous expanded polytetrafluoroethylene film having a porous structure of interconnected nodes and fibrils as described in USP 3,953,566 (Gore) and USP 4,187,390 (Gore), and is manufactured by W.L.Gore and Associates, Inc.
The porous film may be coated with a continuous substantially air-impermeable layer of hydrophilic water-vapor-permeable polymer.
The coating increases the barrier properties of the porous film such as liquid water penetration resistance, windproofness, and ; heat transfer resistance while continuing the important comfort related properties of water vapor transmission through the film and low tensile modulus; the coated film having, at 25% extension in the transverse direction, an F/D ratio less than 3.5.
Hydrophilic water-vapor-permeable polymers are known in the art and are avaitable commercially. Most preferred for the coated film of the composite material of the invention-is a hydrophilic water-vapor-permeable polyurethane polymer of the type described in USP 4,194,041 (Gore,et al) or, alternatively, of the type described in USP 4,532,316 (Henn).
The fabric of the layered composite material of the invention ; has lower tensile modulus in the transverse direction than in the machine direction and an F/D ratio, at 25% extension in the transverse direction, less than 3.5. Knit fabric is preferred for - its ability to stretch and recover from stretching. Most preferred is circular knit fabric. Circular knit fabric includes both single knit and double knit fabric of the type: Jersey, double jersey, jacquard double jersey, interlocks, narrow and broad rib, and the like. Furthenmore, the fabric may be processed to provide greater loft as exemplified by fleece, pile, brushed, or velour fabrics, and the like. Such fabrics are well known to have high softness, drapeability, stretchability and stretch-recovery.
3s The fabric can be made from yarn of synthetic fibers or natural fibers, or blends of synthetic and natural fibers, depending on the intended application of the fabric. For example, for external wear and outer garment use fabric of polyamide, w O 93/21013 ~, A ~ 4 -5- PCI`/US92/0380X
polyester, polyacrylic, or other synthetic fibers may be preferred for their mechanical properties and environmental resistance. On the other hand, for inner wear or undergarment applications, where fabric hand, skin-~eel, water wicking and heat transfer properties assume much greater importance, natural fibers such as cotton or wool may be preferred.
The adhesive to bond together the layers of the composite material of the invention may be selected from many known in the art. Suitable adhesives may be found in, but not limited to, the class consisting of thermoplastic polymers, thermosetting polymers, or reaction curing polymers. They may be applied to the surfaces to be laminated by conventional means, for example by coating or printing methods. Also, in embodiments incorporating the coated film described hereinabove, the hydrophilic polyurethane polymer of the coating may be used to adhesively bond the coated film layer to the fabric layer. The method and material selected for adhesively bonding the layers is based on end use requirements projected for the composite material.
TEST DESCRIPTlONS
WATER VAPOR TRANSMISSION RATE (WTVR) . -A description of the test employed to measure water vapor transmission rate (WVTR) is given below. The procedure has been found to be suitable for testing films, coatings, and coated products.
2S In the procedure, approximately 70 ml. of a solution consisting of 35 parts by weight of potassium acetate and 15 parts by weight of distilled water was placed into a 133 ml.
polypropylene cup, having an inside diameter of 6.5 cm. at its mouth. An expanded polytetrafluoroethylene (PTFE) membrane having a minimum WVTR of approximately 85,000 9/m2/24 hrs. as tested by the method described in U.S. Patent 4,862,730 to Crosby and available from W. L. Gore & Associates, lnc. of Newark, Delaware, was heat sealed to the lip of the c~p to create a ~aut, leakproof, microporous barrier containing the solution.
W O 93/21013 ~ A ~ 4 -6- PCT/US92/03~0X
A similar expanded PTFE membrane was mounted to the surface of a water bath. The water bath assembly was controlled at 23C plus 0.2C, utilizing a temperature controlled room and a water circulating bath.
s ~he sample to be ~ested was allowed to condition at a temperature of 23C and a relative humidity of 50X prior to performing the test procedure. Samples were placed so the microporous polymeric membrane was in contact with the expanded polytetrafluoroethylene membrane mounted to the surface of the water bath and allowed to equilibrate for at least 15 minutes prior to the introduction of the cup assembly.
The cup assembly was weighed to the nearest 1/10009. and was placed in an inverted manner onto the center of the test sample.
Water transport was provided by the driving force between the lS water in the water bath and the saturated salt solution providing water flux by diffusion in that direction. The sample was tested for 15 minutes and the cup assembly was then removed, weighed again within 1/10009.
The WVTR of the sample was calculated from the weight gain of the cup assembly and was expressed in grams of water per square meter of sample surface area per 24 hours.
TENSILE TEST
The tensile properties of the materials were determined using a constant rate-of-jaw separation type machine (Instron testing machine, Model 1122).
Materials were cut into 2.54 centimeter wide strips in both machinè and transverse directions. Samples were allowed to condition in a controlled room at a temperature of 21-C and 65%
relative humidity.
The gauge length of the test was 5.08 centimeters and the strain rate was 500% / minute. All samples were tested to break.
The tensile modulus of the materials is reported as the force to displacement (F/D) ratio obtained by dividing the tensile force (expressed in Ne~tons) to stretch a test specimen to 1.25 times its W0 93/21013 ~ 4 -7- PCI/US92/0380X
original length (25% extension) divided by the displacement (expressed in centimeters) to reach 25% extension.
AIR PERMEABILITY - Hiqh Flow Rate Method Air permeability was measur2d by clamping a test sampie in a ~- 5 gasketed flanged fixture which provided a circular area of approximately 39 square centimeters (about 7 centimeters diameter) for air flow measurement. The upstream side of the sample fixture was connected to a flow meter in line with a source of dry compressed air. The downstream side of the sample fixture was open to the atmosphere.
Testing was accomplished by applying a pressure of 12.7 millimeters of water to the upstream side of the sample and recording the flow rate of the air passing through the in-line flowmeter (a ball-float rotameter).
lS The sample was conditioned at 70-F and 65% relative humidity for at least 4 hours prior to testing.
Results are reported as cubic centimeters/minute/square centimeter of sample, at 12.7 millimeters water pressure.
AIR PERMEABILITY - Low Flow Rate Method The resistance of samples having relatively low air permeability flow was measured by a Gurley densometer (ASTM D726-58j manufactured by ~. ~ L.E. Gurley ~ Sons. The results are obtained in terms of Gurley Number which is the time in seconds for 100 cubic centimeters of air to pass through 6.45 square centimeters of a test sample at a pressure drop of 12.4 centimeters of water.
PORE SIZE MEASUREMENT
Pore size measurements are made by the Coulter Porometer (TM), ;~- manufactured by Coulter Electronics, Inc., Hialeah, FL.
0 The Coulter Porometer (TM) is an instrument that provides , WO93/21013 !~ A ~ 8- PCT/US92/0380X
automated measurement of pore size distributions in porous media using the liquid displacement method (described in ASTM Std. F316-86).
EXAMPLES
ExamDle 1 This example demonstrates a three-layer embodiment of the stretchable water-vapor-permeable composite material and employs - the following materials: two layers of a circular knitted fabric piled on one side, and a porous polymeric film.
The knitted napped fabric was made from a polyester yarn, had lower tensile modulus in the transverse direction than the machine direction and weighed 122 g/m2. The knitted napped fabrics, Styles #7868 and #7869, were obtained from Malden Mills, Lawrence, MA
01841. Properties are shown in Table 1.
The porous polymeric film was a porous expanded polytetrafluoroethylene film as described in USP 3,953,566 (Gore), - manufactured by W.L.Gore ~ Associates, Inc. of Newark, DE. Thefilm was prepared from polytetrafluoroethylene fine powder using paste extrusion and calendering techniques and was expanded in both machine direction and transverse direction. The porous expanded pol~ytetrafluoroethylene film had lower tensile modulus in the transverse direction than the machine direction, weight of about 4 grams/m2, pore volume of about 82%, and thickness of about 12 micrometers. Addittonal properties are shown in ~able 1.
2S The 3-layer composite material was prepared by a lamination -`
process. The sequence of the lamination process was (1) `
application of adhesive by a gravure roll to one side of the porous expanded polytetrafluoroethylene film, (2) combining a layer of the knitted napped fabric to the adhesive side of the film by nipping between two rolls, (3) application of adhesive by a gravure roll to -the fi1m side of the resulting 2-layer compos~te, and (4) combining a second layer of knitted napped fabric to the film side of the composite by nipping between two rolls.
, The lamination equipment was a multi-roll stack configuration w o 93/21013 ~ A~ 4 PCT/US92/03808 laminator which had a heated metal gravure printing roll. A feed -reservoir on the heated gravure printing roll contained hot melt -polyurethane adhesive of the type described in USP 4,S32,316 (Henn) which was printed in a discontinuous pattern on the porous expanded polytetrafluoroethylene film as it passed through the nip of the ~;~gravure roll and a metal press roll. The adhesive printed film was then adhered to the non-napped surface of the circular knitted -fabric by passage through the nip of the metal press roll and a silicone rubber surfaced roll, thus forming a 2-layer composite material.
~he 2-layer composite material was then fed to a second multi-roll stack configuration laminator. As described above, the adhesive was printed in a discontinuous pattern on the porous expanded polytetrafluoroethylene film of the 2-layer composite ;material which was then adhered to t~e non-napped surface of the second layer of circular knitted fabric to form a 3-layer stretchable water-vapor-permeable composite material in which the ~-axes of lower tensile modulus of the materials of the layers are in parallel alignment. ~-The pattern of adhesive application and the amount of adhesive applied can also influence the softness, drape and feel of the composite material as well as the mechanical properties of the composite material such as bond strength, stretch and stretch-. .
recovery. It is recognized 1n the art that, for lamination of different knltted fabrics than used in the example above, some ~`
.
experimentation may be needed to detenmine the optimum adhesive ~`
laydown pattern and amount to obtain the deslred properties in the composlte material.
Table 1 Fabric 1 Fabrlc 2 Both eP~FE 3-Layer i``
ProDertY #7868 #7869 Fabrlcs Film Laminate '`
WVTR ~ ~ 12950 13670 7815 >80000 7675 Air Permeabllity>3000 >3000 NM 39.6 ~!30.5 F/D Ratio (trans.) 2.63 1.37 NM 1.08 6.84 (cm3/min/cm2 at 12.7 mm water pressure) NM ^ (Not Measured) . -.
.... ... .. .. .... . .
w O 93/21013 C A ~ 4 -lo- PCr/US92/03808 The 3-layer stretchable water-vapor-permeable camposite material of Example I had excellent softness and drape characteristics. It required a low force to stretch at least 25%
s and exhibited stretch-recovery greater than 90%. It also had excellent windproofness, as indicated by the low air permeability values in Table I, and excellent WVTR properties.
' ~ ' ComDarative ExamDle 1 A three-layer composite material was prepared for comparative purposes. Materials and processing were as described in Example I
above except that a tifferent porous polymeric film was used.
~ he porous polymeric film was a porous expanded polytetrafluoroethylene film as described in USP 3,953,566 (Gore), manufactured by W.L.Gore ~ Associates, Inc. The membrane was prepared from polytetrafluoroethylene fine powder using paste extrusion and calendering techniques and was expanded in the transverse direction. The porous expanded polytetrafluoroethylene film had higher tensile modulus in the transverse direction, and an F/D ratio, at 25X extension in the transverse direction, greater .~ than 3.S. The porous expanded polytetrafluoroethylene film had a weight of about 17 grams/m2, a pore volume of about 82X, and a thickness of about 43 micrometers. Properties are shown tn Table 2.
In contrast to the composite materials of the invention, the layers of the comparative example were oriented such that the axis of lowest~tensile modulus of the porous expanded polytetrafluoroethylene film was perpendicular to the axis of lowest tensile modulus of the fabric.
.-~ :: , '~
' . :
W O 93~21013 ~ A ;~ pc~r/us92/o38o8 Table 2 ~-Fabric 1 Fabric 2 Both eP~FE 3-Layer ProDertY ~7868 #7869 Fabrics Film Laminate ;
s WVTR 12950 13670 7815 >80000 7675 Air Permeability *>3000 >3000 NM <30.5 <30.5F/D Ratio (trans.) 3.64 1.37 NM 11.6 16.2 * (cm3/min/cm2 at 12.7 mm water pressure) `-NM - Not Measured The material of the comparative example had relatively poor softness and drape characteristics compared to the material of Example 1, and the force required to stretch the material 25% was excessive.
.
ExamDle 2 '`~
This example demonstrates a two-layer embodiment of the stretchable water-vapor-permeable composite material and employs `r''~' the following materials: a layer of circular knitted brushed cotton fabric, and a porous polymeric film coated with a continuous substantially air-impermeable layer of hydrophilic polyurethane ~`
polymer. !~
The circular knitted brushed cotton fabric was Style 6900 fabric obtained from Milliken ~ Co. The fabric had lower tensile `
modulus in the transverse direction than in the machine direction and a weight of approximately 170 g/m2. Additional properties are shown in ~able 3.
~he porous polymeric film was a porous expanded polytetrafluoroethylene film as described in USP 3,953,566 (Gore), manufactured by ~.L.Gore ~ Associates, Inc.. The film was prepared from polytetrafluoroethylene fine powder using paste extrusion and calendering technlques and was expanded in both machine direction and transverse direction. The porous expanded polytetrafluoroethylene film had lower tensile modulus in the transverse direction than in the machine dlrection, a weight of about 2-3 grams/m2, a pore volume of about 82X, and a thickness of W O 93/21013 C A ~ 4 -12- PCl/US92/0380X
about 8 micrometers Additional properties are shown in Table 3 The 2-layer composite material was prepared by a lamination ;
process in which the porous expanded polytetrafluoroethy~ene film was (1) coated w1th a continuous layer of hydrophilic polyurethane s polymer and then (2) combined with the kn1tted brushed cotton fabric by nipping between two rolls; the continuous layer of hjdrophilic pol~urethane served as ~dhesive to bond the layers together The hydrophilic polyurethane polymer was a reactive hot melt hydrophilic polyurethane prepared according to the teachings of USP 4 532 316 (Henn) The coating/lamination equipment used was a roll coater in a -~
4-roll stack configuration The stack included a heated metal gravure roll having ~ mounted feed reservoir containing the hot melt polyurethane po~ymer The gr~vure roll transferred the lS polyurethane polymer to a fluoroelastomer surfaced roll The fluoroelastomer surfaced roll appl1ed a continuous layer of the polyurethane polymer to the surface of the porous expanded polytetrafluoroethyl-ne f11m as the f11m ~as nipped bet~een the fluoroelasto~er surfaced roll ~nd a heated ~etal press roll The fabric was co~b~ned ~1th the porous expanded polytetrafluoroethylene f~lm on the oppos1te s1de of the metal press roll as the~ passed through the n1p bet~een the ~et~l press roll and a s~l~cone rubber surf-ced roll ....
` T~ble 3 : ....
, .
F-br1c ePTFE Co-ted 2-L~jer ProDèrtv #6900 F11m _Ell~Lamtnate ~VTR N~ ~80000 N~ 18909 A1r Pcr~eab~llty~ >3000 ~6 <0 3 <0 3 F/D Rat~o (trans ) 1 56 0 20 0 68 3 03 * (c~3/~in/cr2 ~t 12 ~ _ n ter prcssure) NM - Not Measured T~e 2~ r stretchable ~-ter- n por-perueable co~poslte ~ater1al of Ex-~ple 2 h * exeellent softness and drape char~cter1st1cs It requ1red very lo~ force to stretch at least 25X and exh1b~ted stretch-recovery gre~ter than 90X It also had 3 ~,A~I i io~ -13- PCr/US92/0380X
, excellent windproofness and excellent WVTR properties.
The low flow rate test method was used to measure air permeability of the material of Example 2 and, for consistency in reporting, results were converted to cm3/min/cm2 at 12.7 mm water s pressure as shown in Table 3.
Due to high uptake of moisture by the composite material of Example 2, the test time for WVTR measurements shown in Table 3 was ;
extended from 15 minutes to 30 minutes to permit steady state conditions to be reached.
lo The composite material of Example 2 was fashioned into undergarments. The undergarments were worn with the brushed cotton surface next the skin and the coated polytetrafluoroethylene film surface outward and were found to be unexpectedly comfortable by the wearers. The mechanically related comfort properties such as skin-feel, softness, ease of stretching and amount of stretch-recovery were found to be excellent, however, the greatest surprise was due to the exceptional temperature/humidity control provided by the undergarments. The mechanism for this is not fully understood, but it is felt that the high loft and high moisture wicking characteristics of the brushed cotton fabric in conjunction with the high water vapor transmission rate and lack of air movement through the composite material combine to quickly develop, and then maintain, a comfortable microclimate next the skin.
TITLE OF THE INVENTION
SOFT STRETCHABLE COMPOSITE FABRIC
FIELD OF THE INVENT10~1 This invention is related to stretchable layered composite fabrics, more particularly, to layered composite fabrics which provide barrier properties with water vapor permeability.
;~ BACKGROUND OF THE INVENTION
..
Knitted fabrics are generally softer, more drapeable, offer less resistance to stretching and can be stretched without damage further than woven fabrics. These comfort related properties are very important considerations in the design and manufacture of many types of lightweight or close-fitting garments.
~ , Lightweight knitted fabrics have a relatively open `-construction, exhibit high air permeability and, consequently, haYe virtually no barrier properties such as windproofness or thermal insulation qualities. This severely limits the outdoor applications in colder weather without additional outer layers.
It is very desirable to enhance the barrier properties of the lightweight knitted fabrics while continuing to provide comfort related properties such as softness, drapeability, stretchability, stretch-recovery and water-vapor-permeability.
SUMMARY OF THE IN~/ENTION
This invention provides soft drapeable stretchable water-vapor-permeable layered composite materials having low tensile modulus in the transverse direction and having functional properties such as windproofnesst water-vapor-permeabilityt weather resistance or waterproofness.
8y tensile modulus" it is meant the resistance of a material to be stretched or elongated. It is expressed herein in terms of w 0 93/21013 C ~ 2 i I /6~ ` -2- PCT/US92/0380X
the force (F) required to stretch or elongate the material a specified distance (D).
By "windproofness" it is meant a low rate of permeability of air through the material. It is expressed herein in term~ of the s volume of air (cm3) passing through a given area (cm2) in a given time (min) under a given pressure drop (mm water pressure).
The force to displacement (F/D) ratio as used herein is the ratio obtained by dividing the tensile force ~expressed in Newtons) to stretch a 2.54 cm wide specimen to 1.25 times its original o length (25% extension) by the displacement (expressed in centimeters) to reach 25% extension.
Transverse direction is used herein to indicate the direction in the plane of manufacture perpendicular to the machine direction (direction of manufacture). The materials of the layers described herein are considered to be planar, defined by their length (machine direction) and width (transverse direction).
The composite material of the invention can comprise a layer of porous film adhesively laminated to a 7ayer of fabric; the - porous film and the fabric each having, at 25% extension in the transverse direction, an F/D ratio per 2.54 cm width less than 3.5;
and the composite material having an F/D ratio less than 9Ø
Another embodiment of the composite material of the invention can comprise a layer of porous film to each side of which is adhesively laminated a layer of fabric; the porous film and the fabric each having, at 25X extension in the transverse direction, an f/D ratio less than 3.5; and the composite material havin~, at 25% extension in the transverse direction, an F/D ratio less than 9Ø
By "porous" is meant that the film has pores or voids from one side to the other.
To enhance barrier properties such as windproofness or waterproofness the porous film of the embodiments above may be - coated with a continuous substantially air-impermeable layer of hydr~Rhilic water vapor-permeable polymer, e.g. a polyurethane, which prevents passage of liquid water through it, but has high water-vapor-permeability.
The stretchtble water-vapor-permeable layered composite material of the invention has excellent drape characteristics and W093/21013 ~A ~ i 1 I h~4 3 PCr/US92/03XOX
can be substantially stretched in the transverse direction by application of very low forces without loss of important functional characteristics such as windproofness, water-vapor-permeability, weather resistance or waterproofness.
s To enhance these properties, the axes of lower tensile modulus of the layers of the composite are aligned in substantially parallel orientation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The layered composite materials of the invention are lo engineered to enhance softness, drape, stretchability and stretch-recovery, and to minimize resistance to stretching in the transverse direction, first through selection of component materials, each preferably having high softness, drape, stretchability and stretch-recovery, and each having lower tensile modulus in the transverse direction than in the machine direction;
and secondly, in contrast to conventional practices, by aligning the axis of lowest tensile modulus of each layer in the same direction with respect to its neighboring layers. Thus, it can be seen that an important element in the construction of the layered composite material of the invention is the relative orientation of the tensile properties of each layer.
A preferred embodiment of the stretchable water-vapor-- permeable composite material of the invention comprises a layer of porous film adhesively laminated to a layer of fabric. Another preferred embodiment of the invention comprises a layer of porous film to each side of which is adhesively laminated a layer of fabric.
~he porous film may have a pore volume in the range 40 - 95 percent, preferably 60 - 95 percent; a mean pore s~ze smaller than ~- 30 about 2 m~crometers, preferàbly smaller than 1 ~icrometer; air ;~ permeability less than about 91 cubic centimeters/minute/square ~; centimeter at a pressure drop of 12.7 millimeters water; lower tensile modulus in the transverse direction than in the machine direction, and an F/D ratio, at 25% extension in the transverse 3s direction, less than 3.5. The porous film may be a membrane, mesh, WO 93/21013 C A ~ I 1 / 6 ~ 4 PCl/US92/0380X
or nonwoven web selected from, but not limited to the group:
polyolefin, polyamide, polyester, polyurethane, fluoropolymer, and the like. Such films are known in the art and are commercially available. The preferred film is porous polytetrafluoroethylene, more preferably, porous expanded polytetrafluoroethylene film having a porous structure of interconnected nodes and fibrils as described in USP 3,953,566 (Gore) and USP 4,187,390 (Gore), and is manufactured by W.L.Gore and Associates, Inc.
The porous film may be coated with a continuous substantially air-impermeable layer of hydrophilic water-vapor-permeable polymer.
The coating increases the barrier properties of the porous film such as liquid water penetration resistance, windproofness, and ; heat transfer resistance while continuing the important comfort related properties of water vapor transmission through the film and low tensile modulus; the coated film having, at 25% extension in the transverse direction, an F/D ratio less than 3.5.
Hydrophilic water-vapor-permeable polymers are known in the art and are avaitable commercially. Most preferred for the coated film of the composite material of the invention-is a hydrophilic water-vapor-permeable polyurethane polymer of the type described in USP 4,194,041 (Gore,et al) or, alternatively, of the type described in USP 4,532,316 (Henn).
The fabric of the layered composite material of the invention ; has lower tensile modulus in the transverse direction than in the machine direction and an F/D ratio, at 25% extension in the transverse direction, less than 3.5. Knit fabric is preferred for - its ability to stretch and recover from stretching. Most preferred is circular knit fabric. Circular knit fabric includes both single knit and double knit fabric of the type: Jersey, double jersey, jacquard double jersey, interlocks, narrow and broad rib, and the like. Furthenmore, the fabric may be processed to provide greater loft as exemplified by fleece, pile, brushed, or velour fabrics, and the like. Such fabrics are well known to have high softness, drapeability, stretchability and stretch-recovery.
3s The fabric can be made from yarn of synthetic fibers or natural fibers, or blends of synthetic and natural fibers, depending on the intended application of the fabric. For example, for external wear and outer garment use fabric of polyamide, w O 93/21013 ~, A ~ 4 -5- PCI`/US92/0380X
polyester, polyacrylic, or other synthetic fibers may be preferred for their mechanical properties and environmental resistance. On the other hand, for inner wear or undergarment applications, where fabric hand, skin-~eel, water wicking and heat transfer properties assume much greater importance, natural fibers such as cotton or wool may be preferred.
The adhesive to bond together the layers of the composite material of the invention may be selected from many known in the art. Suitable adhesives may be found in, but not limited to, the class consisting of thermoplastic polymers, thermosetting polymers, or reaction curing polymers. They may be applied to the surfaces to be laminated by conventional means, for example by coating or printing methods. Also, in embodiments incorporating the coated film described hereinabove, the hydrophilic polyurethane polymer of the coating may be used to adhesively bond the coated film layer to the fabric layer. The method and material selected for adhesively bonding the layers is based on end use requirements projected for the composite material.
TEST DESCRIPTlONS
WATER VAPOR TRANSMISSION RATE (WTVR) . -A description of the test employed to measure water vapor transmission rate (WVTR) is given below. The procedure has been found to be suitable for testing films, coatings, and coated products.
2S In the procedure, approximately 70 ml. of a solution consisting of 35 parts by weight of potassium acetate and 15 parts by weight of distilled water was placed into a 133 ml.
polypropylene cup, having an inside diameter of 6.5 cm. at its mouth. An expanded polytetrafluoroethylene (PTFE) membrane having a minimum WVTR of approximately 85,000 9/m2/24 hrs. as tested by the method described in U.S. Patent 4,862,730 to Crosby and available from W. L. Gore & Associates, lnc. of Newark, Delaware, was heat sealed to the lip of the c~p to create a ~aut, leakproof, microporous barrier containing the solution.
W O 93/21013 ~ A ~ 4 -6- PCT/US92/03~0X
A similar expanded PTFE membrane was mounted to the surface of a water bath. The water bath assembly was controlled at 23C plus 0.2C, utilizing a temperature controlled room and a water circulating bath.
s ~he sample to be ~ested was allowed to condition at a temperature of 23C and a relative humidity of 50X prior to performing the test procedure. Samples were placed so the microporous polymeric membrane was in contact with the expanded polytetrafluoroethylene membrane mounted to the surface of the water bath and allowed to equilibrate for at least 15 minutes prior to the introduction of the cup assembly.
The cup assembly was weighed to the nearest 1/10009. and was placed in an inverted manner onto the center of the test sample.
Water transport was provided by the driving force between the lS water in the water bath and the saturated salt solution providing water flux by diffusion in that direction. The sample was tested for 15 minutes and the cup assembly was then removed, weighed again within 1/10009.
The WVTR of the sample was calculated from the weight gain of the cup assembly and was expressed in grams of water per square meter of sample surface area per 24 hours.
TENSILE TEST
The tensile properties of the materials were determined using a constant rate-of-jaw separation type machine (Instron testing machine, Model 1122).
Materials were cut into 2.54 centimeter wide strips in both machinè and transverse directions. Samples were allowed to condition in a controlled room at a temperature of 21-C and 65%
relative humidity.
The gauge length of the test was 5.08 centimeters and the strain rate was 500% / minute. All samples were tested to break.
The tensile modulus of the materials is reported as the force to displacement (F/D) ratio obtained by dividing the tensile force (expressed in Ne~tons) to stretch a test specimen to 1.25 times its W0 93/21013 ~ 4 -7- PCI/US92/0380X
original length (25% extension) divided by the displacement (expressed in centimeters) to reach 25% extension.
AIR PERMEABILITY - Hiqh Flow Rate Method Air permeability was measur2d by clamping a test sampie in a ~- 5 gasketed flanged fixture which provided a circular area of approximately 39 square centimeters (about 7 centimeters diameter) for air flow measurement. The upstream side of the sample fixture was connected to a flow meter in line with a source of dry compressed air. The downstream side of the sample fixture was open to the atmosphere.
Testing was accomplished by applying a pressure of 12.7 millimeters of water to the upstream side of the sample and recording the flow rate of the air passing through the in-line flowmeter (a ball-float rotameter).
lS The sample was conditioned at 70-F and 65% relative humidity for at least 4 hours prior to testing.
Results are reported as cubic centimeters/minute/square centimeter of sample, at 12.7 millimeters water pressure.
AIR PERMEABILITY - Low Flow Rate Method The resistance of samples having relatively low air permeability flow was measured by a Gurley densometer (ASTM D726-58j manufactured by ~. ~ L.E. Gurley ~ Sons. The results are obtained in terms of Gurley Number which is the time in seconds for 100 cubic centimeters of air to pass through 6.45 square centimeters of a test sample at a pressure drop of 12.4 centimeters of water.
PORE SIZE MEASUREMENT
Pore size measurements are made by the Coulter Porometer (TM), ;~- manufactured by Coulter Electronics, Inc., Hialeah, FL.
0 The Coulter Porometer (TM) is an instrument that provides , WO93/21013 !~ A ~ 8- PCT/US92/0380X
automated measurement of pore size distributions in porous media using the liquid displacement method (described in ASTM Std. F316-86).
EXAMPLES
ExamDle 1 This example demonstrates a three-layer embodiment of the stretchable water-vapor-permeable composite material and employs - the following materials: two layers of a circular knitted fabric piled on one side, and a porous polymeric film.
The knitted napped fabric was made from a polyester yarn, had lower tensile modulus in the transverse direction than the machine direction and weighed 122 g/m2. The knitted napped fabrics, Styles #7868 and #7869, were obtained from Malden Mills, Lawrence, MA
01841. Properties are shown in Table 1.
The porous polymeric film was a porous expanded polytetrafluoroethylene film as described in USP 3,953,566 (Gore), - manufactured by W.L.Gore ~ Associates, Inc. of Newark, DE. Thefilm was prepared from polytetrafluoroethylene fine powder using paste extrusion and calendering techniques and was expanded in both machine direction and transverse direction. The porous expanded pol~ytetrafluoroethylene film had lower tensile modulus in the transverse direction than the machine direction, weight of about 4 grams/m2, pore volume of about 82%, and thickness of about 12 micrometers. Addittonal properties are shown in ~able 1.
2S The 3-layer composite material was prepared by a lamination -`
process. The sequence of the lamination process was (1) `
application of adhesive by a gravure roll to one side of the porous expanded polytetrafluoroethylene film, (2) combining a layer of the knitted napped fabric to the adhesive side of the film by nipping between two rolls, (3) application of adhesive by a gravure roll to -the fi1m side of the resulting 2-layer compos~te, and (4) combining a second layer of knitted napped fabric to the film side of the composite by nipping between two rolls.
, The lamination equipment was a multi-roll stack configuration w o 93/21013 ~ A~ 4 PCT/US92/03808 laminator which had a heated metal gravure printing roll. A feed -reservoir on the heated gravure printing roll contained hot melt -polyurethane adhesive of the type described in USP 4,S32,316 (Henn) which was printed in a discontinuous pattern on the porous expanded polytetrafluoroethylene film as it passed through the nip of the ~;~gravure roll and a metal press roll. The adhesive printed film was then adhered to the non-napped surface of the circular knitted -fabric by passage through the nip of the metal press roll and a silicone rubber surfaced roll, thus forming a 2-layer composite material.
~he 2-layer composite material was then fed to a second multi-roll stack configuration laminator. As described above, the adhesive was printed in a discontinuous pattern on the porous expanded polytetrafluoroethylene film of the 2-layer composite ;material which was then adhered to t~e non-napped surface of the second layer of circular knitted fabric to form a 3-layer stretchable water-vapor-permeable composite material in which the ~-axes of lower tensile modulus of the materials of the layers are in parallel alignment. ~-The pattern of adhesive application and the amount of adhesive applied can also influence the softness, drape and feel of the composite material as well as the mechanical properties of the composite material such as bond strength, stretch and stretch-. .
recovery. It is recognized 1n the art that, for lamination of different knltted fabrics than used in the example above, some ~`
.
experimentation may be needed to detenmine the optimum adhesive ~`
laydown pattern and amount to obtain the deslred properties in the composlte material.
Table 1 Fabric 1 Fabrlc 2 Both eP~FE 3-Layer i``
ProDertY #7868 #7869 Fabrlcs Film Laminate '`
WVTR ~ ~ 12950 13670 7815 >80000 7675 Air Permeabllity>3000 >3000 NM 39.6 ~!30.5 F/D Ratio (trans.) 2.63 1.37 NM 1.08 6.84 (cm3/min/cm2 at 12.7 mm water pressure) NM ^ (Not Measured) . -.
.... ... .. .. .... . .
w O 93/21013 C A ~ 4 -lo- PCr/US92/03808 The 3-layer stretchable water-vapor-permeable camposite material of Example I had excellent softness and drape characteristics. It required a low force to stretch at least 25%
s and exhibited stretch-recovery greater than 90%. It also had excellent windproofness, as indicated by the low air permeability values in Table I, and excellent WVTR properties.
' ~ ' ComDarative ExamDle 1 A three-layer composite material was prepared for comparative purposes. Materials and processing were as described in Example I
above except that a tifferent porous polymeric film was used.
~ he porous polymeric film was a porous expanded polytetrafluoroethylene film as described in USP 3,953,566 (Gore), manufactured by W.L.Gore ~ Associates, Inc. The membrane was prepared from polytetrafluoroethylene fine powder using paste extrusion and calendering techniques and was expanded in the transverse direction. The porous expanded polytetrafluoroethylene film had higher tensile modulus in the transverse direction, and an F/D ratio, at 25X extension in the transverse direction, greater .~ than 3.S. The porous expanded polytetrafluoroethylene film had a weight of about 17 grams/m2, a pore volume of about 82X, and a thickness of about 43 micrometers. Properties are shown tn Table 2.
In contrast to the composite materials of the invention, the layers of the comparative example were oriented such that the axis of lowest~tensile modulus of the porous expanded polytetrafluoroethylene film was perpendicular to the axis of lowest tensile modulus of the fabric.
.-~ :: , '~
' . :
W O 93~21013 ~ A ;~ pc~r/us92/o38o8 Table 2 ~-Fabric 1 Fabric 2 Both eP~FE 3-Layer ProDertY ~7868 #7869 Fabrics Film Laminate ;
s WVTR 12950 13670 7815 >80000 7675 Air Permeability *>3000 >3000 NM <30.5 <30.5F/D Ratio (trans.) 3.64 1.37 NM 11.6 16.2 * (cm3/min/cm2 at 12.7 mm water pressure) `-NM - Not Measured The material of the comparative example had relatively poor softness and drape characteristics compared to the material of Example 1, and the force required to stretch the material 25% was excessive.
.
ExamDle 2 '`~
This example demonstrates a two-layer embodiment of the stretchable water-vapor-permeable composite material and employs `r''~' the following materials: a layer of circular knitted brushed cotton fabric, and a porous polymeric film coated with a continuous substantially air-impermeable layer of hydrophilic polyurethane ~`
polymer. !~
The circular knitted brushed cotton fabric was Style 6900 fabric obtained from Milliken ~ Co. The fabric had lower tensile `
modulus in the transverse direction than in the machine direction and a weight of approximately 170 g/m2. Additional properties are shown in ~able 3.
~he porous polymeric film was a porous expanded polytetrafluoroethylene film as described in USP 3,953,566 (Gore), manufactured by ~.L.Gore ~ Associates, Inc.. The film was prepared from polytetrafluoroethylene fine powder using paste extrusion and calendering technlques and was expanded in both machine direction and transverse direction. The porous expanded polytetrafluoroethylene film had lower tensile modulus in the transverse direction than in the machine dlrection, a weight of about 2-3 grams/m2, a pore volume of about 82X, and a thickness of W O 93/21013 C A ~ 4 -12- PCl/US92/0380X
about 8 micrometers Additional properties are shown in Table 3 The 2-layer composite material was prepared by a lamination ;
process in which the porous expanded polytetrafluoroethy~ene film was (1) coated w1th a continuous layer of hydrophilic polyurethane s polymer and then (2) combined with the kn1tted brushed cotton fabric by nipping between two rolls; the continuous layer of hjdrophilic pol~urethane served as ~dhesive to bond the layers together The hydrophilic polyurethane polymer was a reactive hot melt hydrophilic polyurethane prepared according to the teachings of USP 4 532 316 (Henn) The coating/lamination equipment used was a roll coater in a -~
4-roll stack configuration The stack included a heated metal gravure roll having ~ mounted feed reservoir containing the hot melt polyurethane po~ymer The gr~vure roll transferred the lS polyurethane polymer to a fluoroelastomer surfaced roll The fluoroelastomer surfaced roll appl1ed a continuous layer of the polyurethane polymer to the surface of the porous expanded polytetrafluoroethyl-ne f11m as the f11m ~as nipped bet~een the fluoroelasto~er surfaced roll ~nd a heated ~etal press roll The fabric was co~b~ned ~1th the porous expanded polytetrafluoroethylene f~lm on the oppos1te s1de of the metal press roll as the~ passed through the n1p bet~een the ~et~l press roll and a s~l~cone rubber surf-ced roll ....
` T~ble 3 : ....
, .
F-br1c ePTFE Co-ted 2-L~jer ProDèrtv #6900 F11m _Ell~Lamtnate ~VTR N~ ~80000 N~ 18909 A1r Pcr~eab~llty~ >3000 ~6 <0 3 <0 3 F/D Rat~o (trans ) 1 56 0 20 0 68 3 03 * (c~3/~in/cr2 ~t 12 ~ _ n ter prcssure) NM - Not Measured T~e 2~ r stretchable ~-ter- n por-perueable co~poslte ~ater1al of Ex-~ple 2 h * exeellent softness and drape char~cter1st1cs It requ1red very lo~ force to stretch at least 25X and exh1b~ted stretch-recovery gre~ter than 90X It also had 3 ~,A~I i io~ -13- PCr/US92/0380X
, excellent windproofness and excellent WVTR properties.
The low flow rate test method was used to measure air permeability of the material of Example 2 and, for consistency in reporting, results were converted to cm3/min/cm2 at 12.7 mm water s pressure as shown in Table 3.
Due to high uptake of moisture by the composite material of Example 2, the test time for WVTR measurements shown in Table 3 was ;
extended from 15 minutes to 30 minutes to permit steady state conditions to be reached.
lo The composite material of Example 2 was fashioned into undergarments. The undergarments were worn with the brushed cotton surface next the skin and the coated polytetrafluoroethylene film surface outward and were found to be unexpectedly comfortable by the wearers. The mechanically related comfort properties such as skin-feel, softness, ease of stretching and amount of stretch-recovery were found to be excellent, however, the greatest surprise was due to the exceptional temperature/humidity control provided by the undergarments. The mechanism for this is not fully understood, but it is felt that the high loft and high moisture wicking characteristics of the brushed cotton fabric in conjunction with the high water vapor transmission rate and lack of air movement through the composite material combine to quickly develop, and then maintain, a comfortable microclimate next the skin.
Claims (10)
- CLAIMS:
l. A stretchable water vapor permeable composite material comprising a layer of porous film adhesively laminated to a layer of fabric; said porous film and said fabric having lower tensile modulus in the transverse direction than in the machine direction and having their axes of lower tensile modulus in parallel alignment, and each having, at 25% extension in the transverse direction, a force to displacement (F/D) ratio per inch width less than 3.5; and said composite material having, at 25% extension in the transverse direction, an F/D ratio per 2.54 cm width less than 9Ø - 2. The stretchable water vapor permeable composite material of claim l wherein the porous film is porous expanded polytetrafluoroethylene
- 3. The stretchable water vapor permeable composite material of claim 1 wherein the porous film is coated with a continuous substantially air-impermeable layer of hydrophilic polymer, the coated porous film having, at 25% extension in the transverse direction, an F/D ratio less than 3.5.
- 4. The stretchable water vapor permeable composite material of claim 2 wherein the porous film is coated with a continuous substantially air-impermeable layer of hydrophilic polymer, the coated porous film having, at 25% extension in the transverse direction, an F/D ratio less than 3.5.
- 5. The stretchable water vapor permeable composite material of claim 3 or claim 4 wherein the hydrophilic polymer is a hydrophilic polyurethane polymer.
- 6. A stretchable water vapor permeable composite material comprising a layer of porous film to each side of which is adhesively laminated a layer of fabric; said porous film and said fabric having lower tensile modulus in the transverse direction than in the machine direction and having their axes of lower tensile modulus in parallel alignment, and each having, at 25%
extension in the transverse direction, a force to displacement (F/D) ratio per 2.54 cm width less than 3.5; and said composite material having, at 25% extension in the transverse direction, an F/D ratio per 2.54 cm width less than 9Ø - 7. The stretchable water vapor permeable composite material of claim 6 wherein the porous film is porous expanded polytetrafluoroethylene.
- 8. The stretchable water vapor permeable composite material of claim 6 wherein the porous film is coated with a continuous substantially air-impermeable layer of hydrophilic polymer, the coated porous film having, at 25% extension in the transverse direction, an F/D ratio less than 3.5.
- 9. The stretchable water vapor permeable composite material of claim 7 wherein the porous film is coated with a continuous substantially air-impermeable layer of hydrophilic polymer, the coated porous film having, at 25X extension in the transverse direction, an F/D ratio less than 3.5.
- 10. The stretchable water vapor permeable composite material of claim 8 or claim 9 wherein the hydrophilic polymer is a hydrophilic polyurethane polymer.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86966192A | 1992-04-16 | 1992-04-16 | |
| US07/869,661 | 1992-04-16 | ||
| PCT/US1992/003808 WO1993021013A1 (en) | 1992-04-16 | 1992-05-01 | Soft stretchable composite fabric |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2117684A1 true CA2117684A1 (en) | 1993-10-28 |
Family
ID=25354020
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002117684A Abandoned CA2117684A1 (en) | 1992-04-16 | 1992-05-01 | Soft stretchable composite fabric |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0636065A1 (en) |
| JP (1) | JPH07505588A (en) |
| AU (1) | AU2005292A (en) |
| CA (1) | CA2117684A1 (en) |
| FR (1) | FR2690174A1 (en) |
| IT (1) | ITTO930255A1 (en) |
| WO (1) | WO1993021013A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015010208A1 (en) * | 2013-07-24 | 2015-01-29 | Ibco Srl | Breathable laminated material |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2097630A1 (en) * | 1992-12-29 | 1994-06-30 | Ann Louise Mccormack | Stretch-pillowed, bulked laminate |
| US5529830A (en) * | 1994-05-25 | 1996-06-25 | W. L. Gore & Associates, Inc. | Two-way stretchable fabric laminate and articles made from it |
| CA2148392A1 (en) * | 1994-06-06 | 1995-12-07 | Ann Louise Mccormack | Stretch-thinned film and nonwoven laminate |
| ZA9510307B (en) * | 1994-12-20 | 1996-06-11 | Kimberly Clark Co | Mechanically compatibilized film/non-woven laminates |
| US5843057A (en) * | 1996-07-15 | 1998-12-01 | Kimberly-Clark Worldwide, Inc. | Film-nonwoven laminate containing an adhesively-reinforced stretch-thinned film |
| US6139929A (en) * | 1997-03-07 | 2000-10-31 | Porvair Plc | Socks |
| US6623837B2 (en) | 2000-12-27 | 2003-09-23 | Kimberly-Clark Worldwide, Inc. | Biaxially extendible material |
| JP4015434B2 (en) * | 2002-02-14 | 2007-11-28 | ジャパンゴアテックス株式会社 | Laminated fabric |
| JP2006212858A (en) | 2005-02-02 | 2006-08-17 | Japan Gore Tex Inc | Stretchable composite film, composite fabric and manufacturing method of them |
| JP4837346B2 (en) | 2005-09-20 | 2011-12-14 | 日本ゴア株式会社 | Seal tape and textiles using the same |
| JP5049519B2 (en) * | 2006-06-15 | 2012-10-17 | 日本ゴア株式会社 | Stretchable composite fabric and stretched porous polytetrafluoroethylene film |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4194041A (en) * | 1978-06-29 | 1980-03-18 | W. L. Gore & Associates, Inc. | Waterproof laminate |
| US4344999A (en) * | 1980-04-22 | 1982-08-17 | W. L. Gore & Associates, Inc. | Breathable laminate |
| GB2155853B (en) * | 1984-03-01 | 1987-06-10 | Nitto Electric Ind Co | Laminated sheet |
| US4925732A (en) * | 1988-07-27 | 1990-05-15 | W. L. Gore & Associates, Inc. | Breathable flexible laminates adhered by a breathable adhesive |
-
1992
- 1992-05-01 CA CA002117684A patent/CA2117684A1/en not_active Abandoned
- 1992-05-01 EP EP92911935A patent/EP0636065A1/en not_active Withdrawn
- 1992-05-01 WO PCT/US1992/003808 patent/WO1993021013A1/en not_active Application Discontinuation
- 1992-05-01 AU AU20052/92A patent/AU2005292A/en not_active Abandoned
- 1992-05-01 JP JP5518275A patent/JPH07505588A/en active Pending
-
1993
- 1993-04-07 FR FR9304111A patent/FR2690174A1/en active Pending
- 1993-04-15 IT IT93TO000255A patent/ITTO930255A1/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015010208A1 (en) * | 2013-07-24 | 2015-01-29 | Ibco Srl | Breathable laminated material |
Also Published As
| Publication number | Publication date |
|---|---|
| ITTO930255A0 (en) | 1993-04-15 |
| AU2005292A (en) | 1993-11-18 |
| JPH07505588A (en) | 1995-06-22 |
| FR2690174A1 (en) | 1993-10-22 |
| ITTO930255A1 (en) | 1993-10-18 |
| WO1993021013A1 (en) | 1993-10-28 |
| EP0636065A1 (en) | 1995-02-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |