Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
  • D04H1/56—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving in association with fibre formation, e.g. immediately following extrusion of staple fibres
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/37—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/643—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds containing silicon in the main chain
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/21—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/263—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of unsaturated carboxylic acids; Salts or esters thereof
  • D06M15/277—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of unsaturated carboxylic acids; Salts or esters thereof containing fluorine
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
  • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
  • D06N3/007—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by mechanical or physical treatments
  • D06N3/0081—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by mechanical or physical treatments by wave energy or particle radiation
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
  • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
  • D06N3/04—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D06N3/047—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds with fluoropolymers
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
  • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
  • D06N3/12—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins
  • D06N3/128—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins with silicon polymers
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M2200/00—Functionality of the treatment composition and/or properties imparted to the textile material
  • D06M2200/10—Repellency against liquids
  • D06M2200/12—Hydrophobic properties

Definitions

• the present invention relates to nonwoven webs More particularly, the present invention relates to nonwoven webs having liquid impermeability and a resistance to penetration by a liquid impinging on the web
• BACKGROUND Fabrics incorporated into garments may provide protection against external elements such as ram or personal protection against liquid hazards, such as toxic chemicals Consequently, it is desirable that these fabrics, which are sometimes enhanced by chemical treatments, provide the proper repellancy
• fabric refers to a material made from fibers by such methods as weaving, knitting, felting, extruding, spunbonding, and meltblowing
• a fabric includes nonwoven materials woven materials, laminates, coforms, and films
• grafted refers to the bonding, such as covalent bonding, of one material to another
• woven refers a network of crossed and interlaced material
• nonwoven web refers to a web that has a structure of individual fibers which are interlaid (forming a matrix), but typically not in an identifiable repeating manner
• Nonwoven webs have been, in the past, formed by a variety of processes known to those skilled in the art such as, for example, meltblowing, spunbonding, wet-forming and various bonded carded web processes
• spunbond web refers to a web formed by extruding a molten thermoplastic material as filaments from a plurality of fine, usually circular, capillaries with the diameter of the extruded filaments then being rapidly reduced, for example, by fluid-drawing or other well known spunbonding mechanisms
• spunbond nonwoven webs is illustrated in patents such as Appel, et al , U S Patent No 4,340,563
• meltblown web means a web having fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten fibers into a high-velocity gas (e g air) stream which attenuates the fibers of molten thermoplastic material to reduce their diameters Thereafter, the meltblown fibers are carried by the high- velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed fibers
• NRL Report 4364 "Manufacture of Super-Fine Organic Fibers" by V A Wendt, E L Boone, and C D Fluharty
• NRL Report 5265 "An Improved Device for the Formation of Super-Fine Thermoplastic Fibers” by K D Lawrence R T Lukas, and J A Young, and U S Patent No 3,849,241 , issued November 19, 1974, to Buntin, e
• cellulose refers to a natural carbohydrate high polymer (polysaccha ⁇ de) having the chemical formula (C 5 H 10 O 5 ) n and consisting of anhydroglucose units joined by an oxygen linkage to form long molecular chains that are essentially linear Natural sources of cellulose include deciduous and coniferous trees, cotton, flax, esparto grass, milkweed, straw, jute, hemp, and bagasse
• pulp refers to cellulose processed by such treatments as, for example, thermal, chemical and/or mechanical treatments
• coform refers to a material made from nonwoven and pulp fibers
• the term "slurry” refers to a watery mixture of insoluble matter, such as pulp
• the term “fiber” refers to a fundamental solid form, usually crystalline, characterized by relatively high tenacity and an extremely high ratio of length to diameter, such as several hundred to one Exemplary natural fibers are wool, silk, cotton, and asbestos
• Exemplary semisynthetic fibers include rayon
• Exemplary synthetic fibers include spinneret extruded polyamides, polyesters, acrylics, and polyolefms
• the term "weight percent” refers to a percentage calculated by dividing the weight of a material of a mixture by the total weight of the mixture and multiplying this quotient by 100
• percent add-on refers to the percent of material added to a substrate after undergoing a treatment The percent addon is calculated by subtracting the pre-treatment weight from the post- treatment weight and dividing this difference by the pre-treatment weight This quotient is than multiplied by 100 to obtain the percent add-on
• the term “percent reduction in bond strength” refers to the percent reduction in maximum peel load by calculating the maximum peel load difference between a treated and an untreated substrate, dividing this difference by the maximum peel load of the untreated substrate, and multiplying this quotient by 100
• water vapor transmission rate refers to the steady state water vapor flow in unit time through unit area of a body normal to specific parallel surfaces, under specific conditions of temperature and humidity at each surface and may be abbreviated "WV
• the term "normalized” refers to conforming to a norm or standard In the water vapor transmission test procedure, the normalization is the correction of the "base" vapor transmission to a rate proportional to a standard of 5,000 g/m 2 /day for CELGARD ® 2500 microporous film This normalization corrects for variation in oven air inlet humidity
• vapor pressure refers to the pressure exerted by a vapor that is in equilibrium with its solid or liquid form
• permeability refers to the quality or state of a material that determines the amount of a flow that will pass through the material under given conditions per unit time
• non-hygroscopic refers to not readily taking up and retaining moisture.
• hygrometer refers to an instrument for measuring the humidity of the air.
• flange refers to a rim for attachment to another object.
• sample refers to a portion of the production which is taken for testing and is used in the laboratory as a source of test specimens.
• specimen refers to a specific portion of a sample upon which a test is performed.
• the fabric may include a substrate having a coating.
• the coated fabric may have a water vapor transmission rate greater than about 3000 g/m 2 /24 hours, and moreover, may have a rain impact value less than about 0.3 grams at a hydrostatic head of about 91 cm.
• the coating may be selected from the group comprising fluorinated monomers, terpolymers (tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene and vinylidene fluoride such as
• the fluorinated monomers may be selected from the group comprising fluoroacrylate and fluoromethacrylate.
• the coating may be selected from the group comprising fluoroacrylate monomers, terpolymers and siloxanes.
• the substrate may be a nonwoven material, more particularly, a meltblown material.
• the substrate may be a polymer, and more particularly may be selected from the group including polyolefins, polyesters, acrylics and polyamides.
• the polymer may be polypropylene. Another embodiment of the present invention is a process of making a barrier fabric.
• the process may include the steps of providing a substrate, applying a active agent solution to the substrate, and exposing the substrate to electromagnetic radiation, thus creating a barrier fabric.
• the process may include an additional step of passing the substrate applied with solution through a nip prior to radiation exposure
• the barrier fabric may have a water vapor transmission rate greater than about 3000 g/m /24 hours and a rain impact value less than about 0 3 grams at a hydrostatic head of about 91 cm
• the active agent may be a fluorinated monomer, and more particularly, a fluoroacrylate
• the fluorinated monomer may be dissolved in an acetone solvent forming between about 1 to about 3 weight percent fluorinated monomer in solution
• the substrate may be a polymer and more particularly, the polymer may be selected from the group comprising polyolefins, polyesters, and polyamides
• a still further embodiment of the present invention is a fabric for providing a barrier to liquids
• the fabric may include a polypropylene substrate
• Figure 1 is an enlarged cross-section view of an exemplary die tip
• Figure 2 is an enlarged, schematic cross-sectional view of another exemplary die tip
• Figure 3 is an enlarged, schematic cross-sectional view of still another exemplary die tip
• Figure 4 is an enlarged cross-section view of an additional exemplary die
• Figure 5 is a bottom, perspective view of an exemplary die tip
• the untreated fabrics or substrates of the present invention may be manufactured from woven materials, non-woven materials, laminates, and films These substrates may include natural fibers, such as wool, polymers, or mixtures thereof
• Polymers used to manufacture substrates may include polyolefins, such as polyethylene, polypropylene, and polybutylene, polyesters, polyamide polymers, such as nylon, and polyesters, such as polyethylene terephthalate, acrylics, or mixtures thereof
• An exemplary material is polypropylene, sold under the trade designation EXXON 3746G or EXXON 3505 by Exxon Chemical Company of Houston, Texas, or HIMONT PF-015 by Montell Polyolefins of Wilmington, Delaware
• the substrate used in the present invention may have several properties relating to
• the substrate may have an average fiber diameter from about 2 microns to about 7 microns as measured by scanning electron micrographs and image analysis Furthermore, the substrate may have an apparent web density from about 0.8 g/cm 3 to about 2 g/cm 3 as measured by dividing the mass by the volume (area times thickness). Moreover, the substrate may have a basis weight from about 0.5 osy (17 g/m 2 ) to about 3 osy (102 g/m 2 ). Desirably, the substrate may have a basis weight of about 1.5-3 osy (51-102 g/m 2 ). The thickness of the substrate may range from about 0.015 in. (0.038 cm) to about
• the substrate is a meltblown web having a pore size of about 5-10 microns.
• This web may be formed by a meltblown process, such as disclosed in U.S. Patent No. 4,526,733 to Lau, which is hereby incorporated by reference.
• a desired melt temperature for the polymer in the die may range from about 400 ° F (204 ° C) to about 550 ° F (288 ° C), and more desirably from about 430 ° F (221 ° C) to about 500 ° F (260 ° C).
• the desired melt temperature for the polymer in the die may range from about 380 ° F (193 ° C) to about 700 ° F (371 ° C), and more desirably, from about 400 ° F (204 ° C) to about 550 ° F (288 ° C).
• Exemplary pressures and temperatures of the air entering the die through a conduit may range from about 400 ° F (204 ° C) to about 550 ° F (288 ° C) and from about 2 psig ( 13,800 Pa) to about 20 psig ( 138,000 Pa), and more desirably, from about 430 ° F (221 ° C) to about 500 ° F (260 ° C) and from about 4 psig ( 27,600 Pa) to about 12 psig ( 82,760 Pa).
• exemplary temperatures of the air entering the die through a conduit may range from about 70 ° F (21 ° C) to about 550 ° F (288 ° C), and more desirably from about
• the difference in temperature between the polymer in the die and the incoming air may vary from about 0 ° F (0 ° C) to about 500 ° F ( 278 ° C), or alternatively, may vary from about 200 ° F (111 ⁇ C) to about 300 ° F (167 ° C).
• the forming height, which is the distance between the exit of the die and the top surface of the belt may range from about 3 in. (8 cm) to about 20 in. (51 cm), and more desirably, from about 5 in. (13 cm) to about 9 in. (23 cm).
• the polymer through-put may range from about 0.7 (lbs per in.)/hr (125 (g per cm)/hr) to about 5 (lbs per in.)/hr (446 (g per cm)/hr), and more desirably, about 0 7 (lbs per in )/hr (125 ( ⁇ per cm)/hr) to about 1 5 (lbs per in )/hr (268 (g per cm)/hr)
• an exemplary meltblown process also may include a heating element for warming the die tip
• the die 10 may include a body 14, a die tip 18, and air plates 30A-B
• the die tip 18 may be attached to the body 14 using any suitable means, such as bolts 28A-B
• the air plates 30A-B may be secured proximate to the die tip 18 using any suitable means such as bolts 32A-B
• the body 14 and die tip 18 may form a passageway 22 terminating in a narrow cylindrical outlet 26 for ejecting polymer material Generally, this outlet 26 may have a diameter of about 0 0145 in ( 0 0368 cm) and a length of about 0 1 in (0 254 cm)
• the die tip 18 and air plates 30A-B may form channels 36A-B for allowing air past the outlet 26 for expelling polymeric fibers out the gap 38
• the die tip 18 is in a recessed configuration
• the die tip may include a tip 24, a heat insulative coating 46, a heat absorbent coating 48, and a screen filter 20
• the insulative coating 46 may be a low heat conductive material, such as ceramic paint
• the absorbent coating 48 may be a high heat absorbent material, such as black stove paint
• the air plates 30A-B may include bolts 32A-B, spacing shims 34A-B, and heating elements 42A-B
• the bolts 32A-B and spacing shims 34A-B may be used to adjust the air plates 30A-B and with respect to the die tip 18
• At least one heating element 42A-B may be used, but desirably, two heating elements 42A-B may be utilized
• the heating elements 42A-B may be resistant electric cartridge heaters or electromagnetic radiation emitters
• the heating elements 42A-B may be quartz glass infrared lamps or emitters, such as those available from Hereaus-Amersil of Norcross, Georgia Desirably, these lamps are as small as possible yet give sufficient
• the heating elements 42A-B When the heating elements 42A-B are activated, they typically provide heat proximate to the die tip apex 24
• the heating elements 42A-B may either radiate heat to the tip 18 near the die tip apex 24 where the heat may travel to the apex 24 by conduction, or desirably, the heating elements 42A-B may directly radiate heat to the apex 24
• the radiated heat is absorbed by the absorbent coating 48 to aid heating the apex 24, and the insulative coating 46 helps maintain the heat within the tip 18
• the die 100 may include a die tip 118 and a die tip apex 124
• the die tip 118 may have at least one embedded electric cartridge heater, although desirably four embedded electric cartridge heaters 142A-D are used These cartridge heaters 142A-D provide heat to the polymer within the apex 124, and desirably, are positioned as close to the apex 124 as possible
• the die 200 may include a die tip 218 and a die tip apex 224
• the die tip 218 has at least one passage extending the length of the die 200, although desirably four passages 242A-D extend the length of the die 200
• These passages 242A-D may be filled with a heated fluid, such as steam, oil, polymer, wax, air, or water, that is pumped the length of the die 200 to heat a polymer within a die tip apex 224
• these passages 242A-D are positioned as close to the die tip apex 224 as possible
• the die 300 may include a die tip 318, which in turn, may include a positive electrode 342, a negative electrode 344, an electrical insulating layer 352, and a die tip apex 324 Current may flow from the electrode 342 over the apex 324 of the die 300 between orifices 350 to the electrode 344, thereby using resistance to heat the die tip 318, and more desirably, the die tip apex 324 Alternatively, referring to Figure 5, the electrodes 362 and 364 may be placed at either end of the die 300 for causing current to flow lengthwise across the die 300 For either of the sets of electrodes 342 and 344, or 362 and 364, alternating current may be used In some cases, the alternating current may be at a high frequency
• the present invention may form meltblown webs from materials such as polymers
• Exemplary polymers include polyesters, polyolefins, such as polyethylene and polypropylene, polyamides, such as nylon, elastome ⁇ c polymers, and block copolymers These materials may have melt flow rates varying from about 12 to about 1200 decigrams per minute
• Exemplary polypropylenes are sold underthe trade designation EXXON 3746G or EXXON 3505 by Exxon Chemical Company of Houston, Texas, or HIMONT PF-015 by
• Montell Polyolefins of Wilmington, Delaware may have additives to reduce their viscosity, such as peroxide, or additional materials may be placed in the die to impart properties to the extruded polymers, such as fluoroacrylate monomers
• fluoroacrylate monomers The DuPont Corporation of Wilmington, Delaware sells a group of fluoroacrylate monomers underthe trade name ZONYL-T ®
• the fabrics formed by these meltblown processes may have an average pore size of approximately 50 microns or less Desirably, these fabrics may have an average pore size of about 1 to about 10 microns More desirably, these fabrics may have an average pore size of about 2 to about 8 microns
• Fabrics having these pore sizes may be made into garments for providing a liquid barrier
• the substrates may be treated first by applying a solution and then exposing the substrate to electron beam induced grafting
• the solution may include an active agent and solvent
• Active agents may include fluorinated monomers, fluorinated polymers, such as terpolymers of tetrafluoroethylene vinyhdene fluoride and polytetrafluoropropylene, perfluo ⁇ nated polymers, and polyalkyl siloxanes, such as organomodified siloxane emulsions
• An exemplary terpolymer is a fluorothermoplastic sold under the trade designation THV-330R by Dyneon LLC of St Paul, MN.
• An exemplary siloxane emulsion is sold under the trade designation NUDRY TM 30 by the Witco Corporation, OSi Specialties Group, of Sistersville, WV
• fluorinated monomers include 2-Propeno ⁇ c acid, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl ester, 2-Propeno ⁇ c acid, 2- methyl-2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl ester, 2-Propeno ⁇ c acid, pentafluoroethyl ester, 2-Propeno ⁇ c acid, 2-methyl-, pentafluorophenyl ester, Benzene, ethenylpentafluoro-, 2-Propeno ⁇ c acid, 2,2,2-t ⁇ fluoroethyl ester, and 2-Propeno ⁇ c acid, 2-methyl-, 2,2,2-tr ⁇ fluoroethyl ester
• fluoroacrylate monomers that may be used in the solution have the general structure of
• CH 2 CROCO(CH 2 ) x (C n F 2n+1 )
• n is an integer ranging from 1 to 8
• x is an integer ranging from 1 to 8
• R is H or CH 3
• the fluoroacrylate monomer may be comprised of a mixture of homologues corresponding to different values of n
• Monomers of this type may be readily synthesized by one of skill in the chemical arts by applying well-known techniques Additionally, many of these materials are commercially available The DuPont Corporation of Wilmington,
• ZONYL® agents sold underthe designation "TA- N” and "TM” may be used in the practice of the present invention
• Solvents used in the present invention may include halogens, ketones, esters, such as ethyl acetate, and ethers, such as diethyl ether, and water
• Halogens may include chloroform, methylene chloride, perchloroethylene, and halogens sold under the trade designation FREON® by the DuPont Corporation
• Ketones may include acetone and methyl ethyl ketone
• the weight percent of active agent in solution may range from about 0 5 to about 50 Desirably, the weight percent of active agent in solution may range from about 0 5_ to about 30 More desirably, the weight percent of active agent in solution may range from about 1 to about 10
• the substrates may be exposed to an electron beam operating at an accelerating voltage from about 80 kilovolts to about 350 kilovolts. Desirably, the accelerating voltage may be from about 80 kilovolts to about 250 kilovolts. More desirably, the accelerating voltage is about 175 kilovolts.
• the substrate may be irradiated from about 0.1 million rads (Mrad) to about 20 million rads (Mrad). Desirably, the substrates may be irradiated from about 0.5 Mrad to about 10 Mrad. More desirably, the substrates may be irradiated from about 1 Mrad to about 5 Mrad.
• the thickness of samples was determined by the Starrett bulk test which measures the thickness or bulk of a nonwoven or wipe material under a controlled loading pressure of 0.05 lbs/inch psi.
• the specified specimen size is at least 3 inches by 4 inches
• the thickness of a textile material is usually determined as the distance between an anvil, or base, and a pressure foot used to apply the specified pressure.
• Thickness is one of the basic physical properties of textile materials and is a useful measure of performance characteristics. Thickness varies considerably depending on the pressure applied to the specimen when the thickness is measured, and therefore, it is essential to specify the pressure under which the thickness is measured.
• This procedure measures thickness of the designated area under a controlled loading pressure of 0.05lbs/square inch.
• the data is recorded to the nearest 0.001 inch for nonwoven material and to 0.001mm for wipe material.
• Tests are conducted in a standard laboratory atmosphere of about 23 ° C (about 73 ° F) and the material typically is measured after ambient conditions have been met
• a nonwoven product a minimum 5 inch X 5 inch specimen is cut from the roll to be tested
• the test indicator is zeroed, and platen is gently raised by depressing the foot pedal The specimen is placed and centered on a circle over a base, and the platen is gently lowered onto the specimen by releasing the foot pedal After 3 seconds, the display value is read, and for a nonwoven product it is recorded to the nearest 0 001 inch After reading, the display is re-zeroed for further test specimens
• the resistance of fabrics to penetration of water by impact using a standard rain tester is accomplished
• the test is a useful indicator of the probable rain penetration resistance of the fabric
• the rain penetration is applicable to any fabric woven or nonwoven, whether or not it has been treated for water resistance or water repellency
• the test can be used to determine or predict the probable resistance to rain penetration of the fabric, and is especially suitable for measuring the penetration resistance of garment fabrics such as those used for raincoats and the like
• the water resistance of fab ⁇ c depends on the repellant properties of individual fibers as well as on the construction of the fabric as a whole
• the fabric can be tested at different intensities of water impact by changing the pressure on the fabric In this procedure, an 8 inch x 8 inch specimen is used as a protective barrier covering a sheet of pre-weighed absorbent blotting paper A horizontal water spray with a pre-determined hydro-static head is directed against the specimen for exactly 5 minutes and the blotter is then weighed again The difference between the initial and final weights of the blotting paper is the weight of the water that
• the impact rain tester includes two standard spray nozzles, a specimen holder, a rigid frame to support the specimen holder and a shield to shut off spray between tests
• the blotting paper is available from James River Paper Company, in Richmond, Virginia, and is specified as "white AATCC textile blotting paper "
• the testing equipment is located in and the samples are conditioned to the testing atmosphere
• Standard atmosphere for testing is air maintained at a relative humidity of about 50 ⁇ 2% and a temperature of about 73°F Conditioning time is 2 hours, however this time may be shortened if equilibrium is reached Equilibrium is considered to have been reached when the increase in the weight of the specimen, in successive weighings taken at least 30 minutes apart, is less than 0 1 % of the weight of the specimen
• the specimen size is 8 inches x 8 inches
• the water vapor transmission rate was determined using test methods described below
• the fabric to be evaluated was sealed to the top of a cup of water and placed in a temperature controlled environment Evaporation of water in the cup resulted in a relatively higher vapor pressure inside the cup than the vapor pressure of the environment surrounding the outside of the cup This difference in vapor pressure caused the vapor inside the cup to flow through the test material to the outside of the cup The rate of this flow was dependent upon the permeability of the test material sealed to the top of the cup
• the difference between the beginning and ending cup weights was used to calculate the water vapor transmission rate
• the cutting die typically is 2 875 in (7 303 cm) or 3 000 in (7 620 cm) in diameter
• the die may be of the hand held type used with a mallet and cutting board or of the type used in a mechanical die press It is recommended that blotter paper (or any suitably stiff, heavy-weight paper) be used underneath the sample as this allows the sample to be removed from the die more easily
• the blotter paper may be chosen from any type and thickness that can be easily cut using the chosen method of die cutting
• the mallet may be approximately 5 pounds (2 kilograms) with a soft face, which may not be required if using a mechanical die press
• the cutting board may be of any appropriate size and material
• the vapometer cups may be cast aluminum of a flange type
• the cups may be 2 in (5 cm) deep with a mechanical seal and neoprene gasket
• Exemplary cups are sold under part number 681 from the Thwing-Albert Instrument Co , of Philadelphia, PA
• the balance should be capable of holding the vapometer cups and accurate to ⁇ 0 01 gram
• the tray should be suitable for use in transporting the cups to and from the oven, desirably a tray that will allow the maximum number of cups to be placed in the oven at one time
• the tray should be non-hygroscopic and of a material capable of withstanding about 100 ° F (37 7 ° C) for prolonged periods of time
• the tray should have an appropriate lip around its perimeter to contain water in case of spillage
• the oven should be a conve
• the graduated cylinder should have a 100 mL capacity
• An exemplary microporous film used as a control standard is sold under the trade designation CELGARD ® 2500 from the Separations Products Division of Hoechst Celanese Corporation from Charlotte, NC
• the hygrometer should range from 0 to 100 ⁇ 3% relative humidity or equivalent
• the stopcock grease sold under the trade designation THOMAS LUBRISEAL ® or DOW CORNING HIGH-VACUUM GREASE ® may be used The hygrometer and grease may be obtained from Fisher Scientific of Pittsburgh, PA 15219
• the samples were prepared by selecting samples from material that is clean and dry
• the test specimens were taken from areas of the sample that were free of folds and wrinkles and any distortions rendering these specimens abnormal from the rest of the test material
• the number of specimens per sample was chosen for providing the desired level of confidence
• the balance and oven used in this procedure were calibrated regularly to insure accurate and repeatable readings.
• a calibration system was established and maintained, in part, by consulting equipment manufacturers or their literature.
• the apparatus and materials were prepared in the following manner.
• the oven was turned on and set for about 100 ° F (37.7 ° C). The oven temperature was verified that it was holding at a constant temperature. The vapometer cups were checked to ensure that they were clean, dry, and contained no foreign matter.
• Each test specimen along with the two specimens per tray of CELGARD ® 2500 control standard were cut using either the 2.875 in. (7.3 cm) or 3 in. (7.6 cm) diameter die. The specimens were handled carefully to prevent excessive moisture, oils, or other contaminants from accumulating on the specimens, which may cause erroneous results. The samples were tested without any specific preconditioning, however, the samples were checked to ensure that they were free of any surface contamination.
• the testing procedure included labeling each vapometer cup with appropriate identifying information.
• the graduated cylinder was filled with about a 100 ml of room temperature 72 ⁇ 5 ° F or (22.2 ⁇ 3.1 ° C) distilled water and poured into the vapometer cup body.
• This 100 ml of water in the vapometer cup resulted in a water level of 0.75 in. (19 mm) from the top of the cup body.
• This 0.75 in. (19 mm) distance from the water level to the top of the vapometer cup body was critical in maintaining reproducible results from test to test.
• the sealing surface of the vapometer cup gasket was coated with grease.
• the top flange on the vapometer cup body was placed aligning the screw holes in the top flange with the cup body flange.
• the neoprene gasket was positioned contacting the sample to provide a vapor tight seal around the edge.
• the screws were placed in the screw holes and finger tightened evenly.
• Each loaded vapometer cup was weighed and recorded as the "before" weight.
• At least two specimens of CELGARD ® 2500 control standard microporous film were prepared for every tested specimen tray.
• the loaded vapometer cups were carefully transferred to the tray facing up. Care was taken to avoid “sloshing” that would bring the water in the cups into contact with the specimen. If water contacted the specimen due to "sloshing", the results obtained from that specimen were regarded as invalid.
• the specimens were randomly positioned in the tray to avoid grouping together specimens of the same material.
• At least two vapometer cups containing the CELGARD ® 2500 control standard were placed in each tray of specimens. After placing the tray containing the specimens in the oven and the time and relative humidity at the oven air inlet was recorded as the "before" relative humidity reading. The samples remained in the oven for 24 hours. The samples were removed from the oven and the time and the relative humidity at the oven air inlet was recorded as the "after” relative humidity reading. The loaded vapometer cups were immediately weighed and recorded as the "after” weight.
• the correction factor for each tray was calculated with the following formulas.
• the weight lost for each cup containing the test standard was calculated by:
• test standard base rate was calculated by:
• Standard BR cup 1 + Standard BR cup # 2 avg. Celgard ® BR 2
• the correction factor (CF) was calculated as follows
• the standardized WVTR for the specimens was calculated with the following formulas
• the weight lost for each cup containing sample material was calculated as follows
• the specimen base rate was calculated as follows
• the specimen WVTR was calculated as follows
• a substrate was made according to the meltblown process described above from polypropylene sold under the trade designation HIMONT PF-015 from Montell Polyolefins of Wilmington, Delaware. This substrate was divided into three samples. One sample was used as a control and the other two samples were treated. The aminosiloxane dipped samples were passed through nip rolls two times before drying at room temperature. The fluoroacrylate was dipped then hung in a hood to dip dry with some samples and passed through nip rolls with others.
• the two substrates were saturated with an active agent dissolved in a solvent.
• the substrates were saturated with this solution and allowed to dry for about 12 hours.
• the nip rolls were operating under a pressure of about 2.5 pounds per linear inch, which is equivalent to about 0.45 kg/lineal cm.
• the substrates were passed through the electron beam apparatus and irradiated. Afterwards, the samples were dried to a constant weight.
• Table 1 lists samples and the conditions under which the samples were prepared:
• Sample 2 also exceeds the WVTR value while having a rain impact value approaching 0.3 gram at about 91 cm. Although the control has the highest WVTR value, it has a rain impact value a magnitude greater than either of the Samples 1 and 2.
• the treated samples were saturated with an active agent dissolved in a solvent.
• the fabrics were saturated with this solution and allowed to dry for about 12 hours.
• some fabrics were also passed between two rubber nip rolls on a lab wringer prior to drying. The nip rolls were operating under a pressure of about 2.5 pounds per lineal inch 0.45 kg/lineal cm.
• the samples were dried to a constant weight. Afterwards, the substrates were passed through the electron beam apparatus and irradiated.
• Samples , 3, 5, 9, 10, 13, and 15 have a WVTR that exceeds 3000 g/m 2 /24 hours and a rain impact less than 0.3 grams.
• control sample has a rain impact value greater than 0.5 grams. Consequently, the treated fabric of the present invention provides a material that has acceptable breathability and barrier protection.

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