WO2017214390A1

WO2017214390A1 - High temperature liquid splash protective composite and garment

Info

Publication number: WO2017214390A1
Application number: PCT/US2017/036547
Authority: WO
Inventors: Akshay BAUSKAR; Jason Cole; John Langley
Original assignee: Kappler, Inc.
Priority date: 2016-06-08
Filing date: 2017-06-08
Publication date: 2017-12-14

Abstract

A composite structure is provided which is particularly suited for protecting its wearer against spills or splashes of hot substances and flash fire burn. The composite structure comprises a vapor-permeable, liquid-impermeable layer of fluoropolymer sandwiched between a knitted or woven yarns and a breathable microporous non-fluoropolymer layer.

Description

HIGH TEMPERATURE LIQUID SPLASH PROTECTIVE COMPOSITE AND GARMENT Technical Field

[0001] The present disclosure relates to a composite structure suitable for a garment configured for protecting its wearer against splashes or spills of molten metal or hot liquid chemicals, liquid chemical penetration, convective or radiative heat transfer, and flash fire burn. More particularly, the disclosure relates to a protective composite structure comprising a particular multilayer structure being permeable to vapor, thus, "breathable".

BACKGROUND

[0002] Garments typically designed for protection against splashes of corrosive liquids, molten materials, molten metals and the like does not permit passage of vapor. When combined with a typical skin-facing layer, the complete garment is usually very heavy, quite bulky and uncomfortable to wear. Therefore, it is an object of this disclosure to provide a composite that has a higher vapor permeability, and is more comfortable to wear for protection against molten materials, hot liquid chemical penetration, heat transfer and flash fire.

SUMMARY

[0003] In a first embodiment, a composite structure is provided, the composite structure comprising: an outer layer comprising a knitted or woven fabric; a vapor-permeable, liquid- impermeable layer of fluoropolymer bonded on one side to the outer layer; and a skin-facing layer comprising a breathable, microporous non-fluoropolymer layer bonded to the opposing side of the vapor-permeable, liquid-impermeable layer of fluoropolymer. In one aspect, outer layer comprises wool fibers, nylon fibers and flame resistant cellulosic fibers. In one aspect, outer layer comprises an oxidized polyacrylonitrile blend.

[0004] In another aspect, alone or in combination with any of the previous aspects, the fluoropolymer is a fluorohydrocarbon. In another aspect, alone or in combination with any of the previous aspects, the fluorohydrocarbon is poly (tetrafluoroethylene) (PTFE).

[0005] In another aspect, alone or in combination with any of the previous aspects, the breathable, microporous non-fluoropolymer layer is a polyolefin. In another aspect, alone or in combination with any of the previous aspects, the polyolefin is polypropylene. [0006] In another aspect, alone or in combination with any of the previous aspects, the composite structure further comprises a flame resistant adhesive positioned between the outer layer and the fluoropolymer. In another aspect, alone or in combination with any of the previous aspects, the composite structure further comprises a flame resistant adhesive positioned between the skin-facing layer and the fluoropolymer.

[0007] In a second embodiment, a garment is provided, the garment comprising at least a portion thereof of the composite structure of any one of the aspects of the first embodiment.

[0008] In a third embodiment, a method of protecting a wearer from molten metal splash, hot chemical liquid, steam, chemical permeation, and flash fire is provided, the method comprising providing a garment, the garment comprising a composite structure comprising: an outer layer comprising a knitted or woven fabric; a vapor-permeable, liquid-impermeable layer of poly(tetrafluoroethylene) (PTFE) bonded on one side to the outer layer; and a skin-facing layer comprising a breathable, non-PTFE microporous layer bonded to the opposing side of the vapor- permeable, liquid-impermeable layer of poly(tetrafluoroethylene) (PTFE); and protecting the wearer from molten metal splash, hot chemical liquid, steam, chemical permeation, and flash fire.

[0009] In one aspect, protection of the wearerfrom a second-degree burn from molten metal splash or hot chemical liquid is for at least 7 seconds. In another aspect, alone or in combination with any of the previous aspects, protection of the wear from a second-degree burn molten metal splash or hot chemical liquid at a temperature of less than 232°C (450°F) is for at least 7 seconds.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The disclosure will be understood by reference to the attached drawings wherein:

[0010] FIG. 1 is a cross-section of the composite structure disclosed and described herein.

[0011] FIGs. 2A and 2B depict components of a garment or a coverall comprising the composite structure disclosed and described herein.

[0012] FIG. 3. depicts a garment comprising the composite structure disclosed and described herein DETAILED DESCRIPTION

[0013] As used herein, several abbreviations are employed,, the meanings are as follows:

[0014] PTFE: poly(tetrafluoroethylene).

[0015] Of one example of the present disclosure, the composite structure of the disclosure comprises a outer layer 10, a fluoropolymer layer 25, and a breathable, microporous non- fluoropolymer skin-facing layer 30 as depicted in FIG. 1 as a cross-sectional view of the composite structure.

[0016] In one example, outer layer 10 is constructed of a woven or nonwoven fabric configured for preventing molten material splash from penetrating, but which permits vapor to pass through from inside to outside. In one example, outer layer 10 constructed of a flame retardant (FR) woven or nonwoven fabric. In one example, outer layer 10 works in cooperation with a skin-facing layer that can be attached directly to an adjacent sheet or layer, or one or more of each adjacent sheet or layer can be physically separate from the adjacent sheet or layer. The skin-facing layer provides thermal protection and chemical penetration resistance. The outer layer provides resistance from molten metal splash and hot liquid splash for the skin of the person wearing a protective garment comprised of the composite structure.

[0017] In one example, the outer layer is a knit or woven fabric of yarns comprising oxidized PAN fiber blends. In one example, the outer layer is a knit or woven fabric of yarns consisting of oxidized poly acrylonitrile (PAN) blends. In one example, outer layer 10 comprises SPENTEX™ fabric of about 203 g/m² (6.0 ounce/yd²) knit or twill.

[0018] In one example, the outer layer is a knit or woven fabric of staple fibers of FR nylon or nylon blend. In one example, outer layer 10 comprises wool and nylon twill fabric blend of about 200-500 g/m² (5.9-14.7 ounce/yd²) with flame resistant cellulosic fibers (Lenzing FR™; Lenzing AG, Austria) available from TenCate Protective Fibers, (Netherlands), or cellulose fire retardant fiber. Other high temperature or engineering polymers spun into yarn to be used or combined, such as polybenzimidazole (PBI) from Performance Products Inc. (Charlotte, NC).

[0019] In one example, fluorine -containing polymeric layer 25 is a fluorinated hydrocarbon. In one example, layer 25 is configured for no significant shrinkage when exposed to temperatures as high as 300 °C. In one example, the fluorinated hydrocarbon is configured as a membrane such that it is microporous. Such microporous fluorinated hydrocarbon layers are available commercially from Porelle (UK) having a pore size configured to provide for the passage of water vapor with the prevention/elimination of liquid water and other liquids. Average pore size and pore size distribution can be provided to the fluorinated hydrocarbon material by perforation by mechanical or other known methods.

[0020] In one example, the fluoropolymer is a PTFE polymer. In one example, when the skin- facing layer of the garment is in face-to-face relationship with the outer layer, a fluoropolymer, such as PTFE, is present there between. In one example, the fluoropolymer layer 25 is microporous PTFE, with a pore size capable of resisting chemical penetration, but permitting water vapor to pass readily through the sheet. By way of example, as shown in FIG. 1, outer layer 10 and skin-facing layer 30 sandwich a microporous PTFE layer 25. The outer layer 10 and microporous PTFE layer 25 can be ultrasonically, adhesively, or thermally laminated to the skin- facing layer 30. In one example, adhesive 27 is used, e.g., a high temperature resistant adhesive. In one example, the adhesive 27 is breathable. In one example, the adhesive 27 is a breathable, high-temperature resistant adhesive. By way of example, the adhesive 27 can be a polyurethane- based adhesive. The adhesive 27 may contain one or more flame retardant additives or one or more intumescents.

[0021] The outer layer 10 is prepared by ultrasonically, adhesively, or thermally laminating the knit or woven fabric 13 to the fluoropolymer layer. In one example, a thermally resistant adhesive 27 is employed in a manner which securely attaches the fluoropolymer layer laminate but allows the fluoropolymer, e.g., PTFE layer to remain substantially microporous, as well as flexible. The adhesive 27 may be applied in a dot pattern, spider-web pattern, line pattern and the like, to one or both sides of the PTFE layer-or in any other manner or amount, provided that the adhesive pattern does not substantially affect moisture vapor transmission of the surface of the sheet. The adhesive is designated as layer 27 in FIG. 1, shown applied as a dot-pattern, however, other application methods and patterns can be used.

[0022] The total of weight of the outer layer and fluoropolymer layer, including the adhesive, is usually in the range of about 50 to about 500 g/m², preferably in the range of about 300 to 450 g/m². [0023] The skin-facing layer comprises at least one layer of a breathable, microporous polyolefin. In one example, the skin facing layer comprises a breathable, microporous chemical resistant material such that it provides chemical resistance to industrial chemicals and solvents.

[0024] In one example, the skin-facing layer comprises at least one layer of two or more layers of spunlaced nonwoven fabrics. In one example, the spunlaced fabrics are made of polyolefin fibers.

[0025] In one example, skin-facing layer 30 comprises a non-fluoropolymer microporous layer. In one example, the non-fluoropolymer microporous layer comprises at one or more layers, each of which, independently, may be knitted, woven, or nonwoven. In one example, the non-fluoropolymer microporous layer comprises at least two fabrics, which may be non-woven, woven or a combination thereof. Non-PTFE microporous layer maybe microporous polyolefin. The microporous polyolefin can be polypropylene, for example APTRA™ or the like, having a pore size configured to provide for the passage of water vapor with the prevention/elimination of liquid water. Average pore size and pore size distribution can be provided to the microporous polyolefin material by perforation by mechanical or other known methods. Other microporous polyolefins can be employed, such as those sold by Clopay Plastic Products Co.

[0026] The non-PTFE microporous layer may comprise a film from one to five nonwoven spun laced or melt spun fabric layers. In one example, the skin-facing layer 30 comprises ultrasonically, adhesively, or thermally laminated layers of the same or different nonwoven spun laced or melt spun fabric layers. In one example, the non-PTFE microporous layer comprises a hydro-entangled nonwoven fabric. The skin facing layer 30 may be ultrasonically, adhesively, solvent bonded or thermally laminated to the PTFE layer of the outer layer 10. In one example, the PTFE layer may be ultrasonically, adhesively, solvent bonded or thermally laminated to the outer layer. In one example, the skin facing layer 30 maybe adhesively laminated to the PTFE layer of the outer layer using a flame resistant polyurethane adhesive.

[0027] The weight of the skin-facing layer can be in the range of about 13 to 85 g/m², preferably in the range of 20 to 43 g/m².

[0028] In one example, composite structure 100 is a laminate comprising in succession, starting from the layer farthest from the wearer's body, e.g., outer layer 10 of a woven fabric of yarns comprising a oxidized PAN blend bonded to layer 25 comprising microporous vapor- permeable, liquid-water-impermeable PTFE. In another example, the outer layer 10 is a laminate having a repeating structure of an outermost woven fabric comprises yarns of a oxidized PAN blend and a bonded layer 25 of microporous vapor-permeable, liquid-water-impermeable PTFE. In one example, the outer layer 10 comprises one or more flame retardant or intumescent additives.

[0029] In another example, the outer layer 10 is a laminate having an outermost woven fabric of yarns of a wool and nylon twill fabric blend or cellulose fire retardant fiber, and a bonded layer 20 of microporous vapor-permeable, liquid-water-impermeable PTFE layer 25 sandwiched between the outermost layer 10 and a breathable, microporous non-fluoropolymer layer 30.

[0030] In another example, the outer layer 10 is a laminate having an outermost woven fabric of yarns of a oxidized PAN blend and a bonded layer 20 of microporous vapor-permeable, liquid- water-impermeable PTFE layer 25 sandwiched between the outermost layer 10 and a breathable, microporous non-fluoropolymer layer 30.

[0031] In one example, the breathable, microporous non-fluoropolymer layer is configured for providing chemical permeation protection to the wearer. In one example, suitable chemical permeation protection is from liquid and/or volatile chemicals normally associated with industry and industrial operations. In one example, the breathable, microporous non-fluoropolymer layer is configured for providing chemical penetration resistance (as per ASTM F903) protection to the wearer.

[0032] In one example, the composite structure is configured to resist damage during laundering or cleaning. For example, the layer 25 can be combined with cross-linked polyurethane coatings, which penetrates into the fluorocarbon structure enhancing the durability of the composite after multiple washing, wearing and usage.

[0033] In one example, the breathable, microporous non-fluoropolymer skin-facing layer 30 is devoid of PTFE. By way of example, the breathable, microporous non-PTFE, can be constructed of microporous polyolefin. In one example, microporous polyolefin is microporous polypropylene. [0034] In one example, the composite structure of the present disclosure is used in at least a part of a garment that provides its wearer with improved protection against molten materials, chemical permeation, heat transfer, and flash fire. For example, a garment of the disclosure having a skin-facing layer 30 formed with microporous non-fluoropolymer layer, adhesively bonded to PTFE microporous layer 25 that is adhesively bonded to outer layer 10 that is capable of protecting its wearer from molten metal splash or hot chemical liquid of at least 232 °C (450°F), such as molten iron, steel, or aluminum as well as arcs from welding and the like.

[0035] The garment of the present disclosure gives the wearer time to escape from the molten metal environment before such hot metal can raise the temperature of the innermost surface of the garment sufficiently for him to first perceive pain and then some additional seconds, if necessary, removal of the garment before he would receive a first degree burn or second-degree burn.

[0036] A lighter, more comfortable variation of the garment of the present disclosure, with an outer layer 10 of a SPENTEX™ woven fabric or TenCate OASIS™ woven fabric bonded to microporous PTFE layer 25 adhesively bonded to skin-facing layer 30, gives the wearer about 7 seconds to escape from some molten metal splash or hot chemical liquid of 232 °C or less, such as molten lead, gold, or silver. In one example, lower weights of the laminate materials described above can be used and/or configured to provide protection at different temperatures or for specific chemical species.

[0037] A lighter, more comfortable variation of the garment of the present disclosure, without outer layer 10 but just PTFE microporous layer 25 adhesively bonded to a non-PTFE microporous skin-facing layer 30, gives the wearer about 7 seconds to escape from some molten metals of 232 °C or less.

[0038] The disclosure is further illustrated by the following non-limiting examples of preferred embodiments. The results reported in these examples are believed to be representative, but do not constitute all the runs involving the indicated materials. All percentages in the examples are by weight, unless stated otherwise.

[0039] It should be noted that when the garment is in the form of coveralls, two pieces, e.g., separate pants 50 and shirt portions 60 may be provided, as depicted in FIGs 2A and 2B. Alternatively, FIG. 3 depicts a front view of a full-body suit 300 comprising at least a portion of protective laminate fabric 100. Suit 300 is shown as a one-piece suit covering the full body of a wearer. Other configurations of a one-piece suit may be implemented. The front view of the suit 300, as shown in FIG. 3, comprises a sealed hood 312 with a transparent front shield 314, a breathing hose 316, and a front entry 318. As illustrated in FIG. 4, the protective laminate 100 can form a part of a full-body suit. In one example the protective laminate fabric 100, as described herein, comprises a part of protective apparel, such as boots and gloves..

EXAMPLE 1

[0040] This example describes the construction and testing of an outer layer fabric and skin- facing layer fabric, suitable for use in a launderable protective garment of the disclosure. As used herein, "launderable" includes machine washing, handwashing, machine drying and air drying. The tests demonstrate the suitability of the combined fabrics for protecting against molten metal splash or hot chemical liquid at temperatures in the range of at least 230, 250, 275, AND 300 °C.

[0041] A laminate was formed of the following layers of material, in the order listed:

[0042] (1) a commercially available, woven, SPENTEX NGI weighing 203 g/m² (6 oz/yd²);

[0043] (2) a commercially available, heat stable, microporous fluoropolymer layer of poly(tetrafluoroethylene), measuring 0.3-0.4 mm (0.0118-0.0157 in) thick, weighing 55-60 g/m² 60 oz/yd²); and

[0044] (3) a breathable, microporous non-fluoropolymer layer (polypropylene 0.75 oz/yd²; 1.5-1.6 mil (0.038 mm-0.041mm)).

EXAMPLE 2

[0045] A laminate was formed of the following layers of material, in the order listed:

[0046] (1) a commercially available, woven, TenCate "OASIS™ 1000" weighing 340 g/m² (10 oz/yd²);

[0047] (2) a commercially available, heat stable, microporous layer of poly(tetrafluoroethylene), measuring 0.3-0.4 mm (0.0118-0.0157 in) thick, weighing 55-60 g/m² 60 oz/yd²); and

[0048] (3) a breathable, microporous non-fluoropolymer layer (polypropylene 0.75 oz/yd²; 1.5-1.6 mil (0.038 mm-0.041mm)). [0049] The OASIS™ lOOOwoven fabric and the PTFE were adhered to the PTFE layer with high temperature adhesive.

[0050] The OASIS™ 1000/PTFE composite was bonded to the non-fluoropolymer breathable, microporous layer comprised of APTRA™.

[0051] The resultant laminates were used as a composite structure of the disclosure.

[0052] Chemical resistance and chemical penetration of the presently disclosed composite structure was determined by ASTM F903 and ASTM F1930 (2011), respectively. Thus, laminate 100 was tested and found to successfully provide chemical resistance to, but not limited to, petrochemicals, solvents, phenol, sulfuric acid, ethylene glycol, kerosene, and sodium hydroxide, among other chemicals.

[0053] Laminate 100 was also tested for and provided acceptable chemical penetration resistance protection from liquid and/or volatile chemicals normally associated with industry and industrial operations, such as but not limited to acetone, ethyl acetate, toluene, sodium hydroxide, dimethyl formamide, sulfuric acid (93.1% or 96%), Nitro benzene, phenol, benzene, xylene, ethyl benzene, chlorine (65%) among other chemicals

[0054] laminate 100 was also tested for thermal protective performance. A wearer of a garment comprising laminate 100 of the present disclosure, having a skin-facing layer 30 formed with non-PTFE microporous layer, adhesively bonded to microporous PTFE Iayer25 adhesively bonded to a woven outer layer 10 would perceive no pain for at least 7 seconds as per the Thermal Protective Performance Test (ISO-17492) after exposure to the molten metal. ISO- 17492 requires that a fabric sample is subjected to circumstances typical for fires: a constant combination of 50% radiant heat and 50% convective heat, at a constant heat flux of 84 kW/m² (approximately 2 cal/cm²/sec). The ISO-17492 test measures the time that elapses and the amount of heat energy per surface area (TPP value) at which the temperature and energy transferred to the back of the fabric reaches a level which would cause a second-degree burn to the wearer of the Personal Protective Equipment (PPE).

[0055] A wearer of garment of the present disclosure, having a skin-facing layer 30 formed with non-PTFE microporous layer, adhesively bonded to microporous PTFE Iayer25 adhesively bonded to a woven outer layer 10 also passed ASTM F1930 (2011) "ZERO BURN" for 3 seconds. Thus, the garment of the present disclosure provides the wearer with additional seconds to escape from and avoid getting second-degree burns.

[0056] Although particular embodiments of the present disclosure have been described in the foregoing description, it will be understood by those skilled in the art that the disclosure is capable of numerous modifications, substitutions and rearrangements without departing from the spirit or essential attributes of the disclosure. Reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the disclosure.

Claims

We claim:

1. A composite structure comprising: an outer layer comprising a knitted or woven fabric; a vapor-permeable, liquid-impermeable layer of fluoropolymer bonded on one side to the outer layer; and a skin-facing layer comprising a breathable, microporous non-fluoropolymer layer bonded to the opposing side of the vapor-permeable, liquid-impermeable layer of

fluoropolymer.

2. A composite structure of any one of the previous claims wherein the outer layer comprises wool fibers, nylon fibers, and flame resistant cellulosic fibers.

3. A composite structure of any one of the previous claims wherein the outer layer comprises an oxidized polyacrylonitrile blend.

4. A composite structure of any one of the previous claims wherein the fluoropolymer is a fluorohydrocarbon.

5. A composite structure of any one of the previous claims wherein the fluoropolymer is water vapor permeable.

6. A composite structure of any one of the previous claims wherein the breathable,

microporous non-fluoropolymer layer is a polyolefin.

7. A composite structure of claim 5 wherein the polyolefin is polypropylene.

8. A composite structure of any one of the previous claims further comprising a flame resistant adhesive positioned between the outer layer and the fluoropolymer.

9. A composite structure of claim 1 further comprising a flame resistant adhesive positioned between the skin-facing layer and the fluoropolymer.

10. A garment comprising at least a portion thereof of the composite structure of any one of claims 1-9.

11. A method of protecting a wearer from molten metal splash, hot chemical liquid, steam, chemical permeation, and flash fire, the method comprising providing a garment, the garment comprising a composite structure comprising: an outer layer comprising a knitted or woven fabric; a vapor-permeable, liquid-impermeable layer of poly tetrafluoroethylene (PTFE) bonded on one side to the outer layer; and a skin-facing layer comprising a breathable, non-PTFE microporous layer bonded to the opposing side of the vapor-permeable, liquid-impermeable layer of poly tetrafluoroethylene (PTFE); and protecting the wearer from molten metal splash, hot chemical liquid, steam, chemical permeation, and flash fire.

12. The method of claim 11 wherein the composite structure provides protection to the wearer from a second-degree burn from molten metal splash, hot chemical liquid, or steam is for at least 7 seconds.

13. The method of claim 11 wherein the composite structure provides protection to the wearer from a second-degree burn molten metal splash or hot chemical liquid at a temperature of less than 232°C (450°F) is for at least 7 seconds.

14. The method of claim 11 wherein the composite structure passes Thermal Protective Performance Test (ISO-17492).

15. The method of claim 11 wherein the composite structure passes ASTM F903.

16. The method of claim 11 wherein the composite structure passes ASTM F1930 (2011).

17. The method of claim 11 wherein the composite structure Thermal Protective Performance Test (ISO-17492) and ASTM F903.

18. The method of claim 11 wherein the composite structure passes Thermal Protective Performance Test (ISO-17492) and ASTM F1930 (2011).

19. The method of claim 11 wherein the composite structure passes Thermal Protective Performance Test (ISO-17492), ASTM F903, and ASTM F1930 (2011).

20. The method of claim 11 wherein the composite structure passes ASTM F1930 (2011) and ASTM F903.