Laminate and clean room clothing, medical clothing, work clothing produced therefrom

Abstract

Disclosed herein is a gamma sterilization stable laminate having a microporous polyolefin film and a nonwoven support. A variety of protective garments including the laminate are also disclosed.

Description

Technical Field

[0001] The present disclosure relates to a laminate stable to gamma sterilization and protective garments produced from the laminate. More specifically, it relates to a garment formed from a laminate having a nonwoven support and a barrier layer, such as for use as a gamma sterilization stable cover garment, workwear or other protective garment used in various industries. Background Art

[0002] Nonwoven materials and their laminates can be used in various applications. They can be used as medical protective clothing, surgical drapes, clean room clothing, etc. in industrial settings, healthcare, burn units. They can be used as personal protective clothing, drapes in decontamination units, and to maintain sterilization of certain environments such as surgical fields. They can also be used as work clothes in various industrial settings.

[0003] Sterilization is required for many applications. While there are several sterilization techniques available, gamma irradiation is often the sterilization method of choice for a number of reasons.

[0004] However, gamma sterilization of nonwoven materials may cause damage to the nonwoven materials in the form of loss of physical and functional properties. In addition, gamma sterilization is known to cause the sterilized materials to have a significantly reduced shelf life and become foul smelling. Summary of the invention

[0005] In embodiments described herein, a laminate comprises a microporous polyethylene film bonded to a nonwoven support comprising filaments or fibers having a sheath comprising polyethylene and a core comprising polyethylene terephthalate, the laminate being stable to gamma sterilization at doses up to 46 kilogray or greater.

[0006] In embodiments described herein, a cleanroom garment includes a laminate according to one or more embodiments of the present disclosure that meets the requirements of GB19082-2009.

[0007] In an embodiment, a medical protective garment, a chemical protective garment, a suit, and / or a coverall comprises a laminate according to one or more embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1A is a perspective view of a laminate according to an embodiment of the present disclosure.

[0009] Figure 1B According to the embodiments of the present disclosure Figure 1A Side view of the laminate shown in .

[0010] Figure 2is a top view of a laminate according to an embodiment of the present disclosure showing the orientation of the samples tested herein and the tear direction used to determine tear resistance.

[0011] Figure 3 A protective garment according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0012] The present disclosure relates to a laminate comprising a microporous polyethylene film bonded to a nonwoven support, wherein the laminate is stable to gamma sterilization at doses up to 46 kiloGyre or more.

[0013] In an embodiment, the nonwoven support comprises a plurality of core-sheath composite fibers, wherein the core comprises polyethylene terephthalate, and wherein the sheath comprises polyethylene. In an embodiment, the nonwoven support is a spunbond fabric formed by a plurality of core-sheath composite fibers with polyethylene sheath and polyethylene terephthalate core. In an embodiment, the microporous polyethylene film is a single layer. In an embodiment, each layer of microporous polyethylene film bonded to the nonwoven support is bonded to the nonwoven support with an adhesive of about 0.5 grams per square meter (GSM) to 5GSM. In an embodiment, a single layer of microporous polyethylene film is bonded to a single layer of nonwoven support with an adhesive of about 0.5 grams per square meter (GSM) to 5GSM. In an embodiment, the microporous polyethylene film is bonded to the nonwoven support using a discontinuous adhesive layer arranged between the nonwoven support to which the microporous polyethylene film is bonded.

[0014] In an embodiment, the laminate comprises a multilayer microporous polyethylene film, each layer of microporous polyethylene film is bonded to a nonwoven support layer. In an embodiment, the laminate comprises a single layer of microporous polyethylene film bonded to a nonwoven support layer with an adhesive, such as an SF arrangement, wherein S represents a nonwoven support, the "-" symbol represents an adhesive layer, and F represents a microporous polyethylene film. In some embodiments, the laminate comprises a multilayer microporous polyethylene film, each layer of microporous polyethylene film is bonded to one or more layers of nonwoven support layers with an adhesive. In an embodiment, the laminate comprises a multilayer microporous polyethylene film, each layer of microporous polyethylene film is bonded to one or more layers of nonwoven support layers with an adhesive. In an embodiment, the laminate comprises a multilayer microporous polyethylene film, each layer of microporous polyethylene film is bonded to one or more layers of nonwoven support layers with an adhesive, having an SFS arrangement, a FSF arrangement, a (FS)xFS arrangement, wherein x is greater than or equal to 1, an S-(FS)x arrangement, wherein x is greater than 1, a (FS)xF arrangement, wherein x is greater than 1, or any combination thereof. As used herein, it is understood that the designation (FS)x includes an adhesive layer disposed between each subsequent S and F layer, for example, (FS)2 denotes the arrangement FSFS.

[0015] In an embodiment, each layer of microporous polyethylene film bonded to the nonwoven support is bonded to the nonwoven support with about 0.5 grams per square meter (GSM) to 5 GSM of adhesive.

[0016] In embodiments, the laminate has a density of at least about 40 GSM.

[0017] In an embodiment, a cleanroom garment comprises a laminate according to embodiments disclosed herein, wherein the cleanroom garment meets the requirements of Class II medical disposable protective clothing according to GB19082-2009 standard. In an embodiment, a medical garment comprises a laminate according to embodiments disclosed herein, wherein the medical garment meets the requirements of Class II medical disposable protective clothing according to GB19082-2009 standard.

[0018] In an embodiment, a kit includes a laminate according to one or more embodiments disclosed herein.

[0019] In some embodiments, the laminate has a percent decrease in one or more physical properties, including tensile strength, puncture resistance, or tear strength of the laminate, of less than about 20% when measured according to formula (1):

[0020]

[0021] in:

[0022] % decrease refers to the percentage decrease in physical properties;

[0023] Initial properties are physical properties measured according to a method under a set of conditions prior to gamma sterilization; and

[0024] Gamma properties are physical properties measured after gamma sterilization, under the same conditions and according to the same method.

[0025] In an embodiment, the percentage decrease is a percentage decrease in transverse tensile strength of about 10% or less when measured according to formula (I), wherein the % decrease is the percentage decrease in transverse tensile strength; the initial property is the transverse tensile strength measured according to ISO 13934-1 before gamma sterilization; and the gamma property is the transverse tensile strength measured according to ISO 13934-1 after gamma sterilization.

[0026] In an embodiment, the percentage decrease is a percentage decrease in tensile strength in the machine direction of about 18% or less when measured according to formula (I), wherein the % decrease is the percentage decrease in tensile strength in the machine direction; the initial property is the tensile strength in the machine direction measured according to ISO 13934-1 before gamma sterilization; and the gamma property is the tensile strength in the machine direction measured according to ISO 13934-1 after gamma sterilization.

[0027] In some embodiments, the percentage decrease is a percentage decrease in puncture resistance of about 15% or less when measured according to formula (I), wherein the % decrease is the percentage decrease in puncture resistance; the initial property is the puncture resistance measured according to EN 863-1996 before gamma sterilization; and the gamma property is the puncture resistance measured according to EN 863-1996 after gamma sterilization.

[0028] In some embodiments, the laminate has a tensile strength in the transverse direction of 45 N / 50 cm or more when measured according to ISO 13934-1 after gamma sterilization; and / or wherein the laminate has a tensile strength in the machine direction of about 100 N / 50 cm or more when measured according to ISO 13934-1 after gamma sterilization. In some embodiments, the laminate has a tear strength in the transverse direction of about 50 N / 50 cm or more when measured according to ISO 9073-4 after gamma sterilization. In some embodiments, the laminate has a tear strength in the machine direction of about 20 N / 50 cm or more when measured according to ISO 9073-4 after gamma sterilization. In some embodiments, the laminate has a puncture resistance of about 5 N or more when measured according to EN 863-1996 after gamma sterilization. In some embodiments, the microporous polyethylene film is a single layer. In some embodiments, the microporous polyethylene membrane is bonded to the nonwoven support by about 0.5 GSM to 5 GSM of adhesive, and in some embodiments, the adhesive is disposed as a discontinuous layer between the microporous polyethylene membrane and the nonwoven support, such as in dots.

[0029] For purposes herein, the density of a laminate or support is disclosed in grams per square meter, which may be abbreviated as GSM. A disclosure of a specific density as "about" a specific density should be interpreted as ±5 GSM. For example, a laminate having a density of about 70 GSM may have a density from 65 GSM to 75 GSM.

[0030] For purposes herein, gamma sterilization refers to exposing a laminate or an article comprising a laminate to gamma radiation at a dose of up to about 46 kiloGrays (kGy) or more, where Gray is defined as one joule of radiation energy absorbed per kilogram of material. In an embodiment, gamma radiation sterilization is performed by exposing the product to cobalt-60 isotope under conditions and time periods sufficient to produce a total dose of gamma radiation of up to 46 kiloGrays or more to penetrate the entire product, thereby inactivating any microorganisms that may be present. For purposes herein, a laminate is considered to be stable to gamma sterilization of up to 46 kiloGrays or more when the percentage decrease in one or more physical properties of the laminate selected from the tensile strength of the laminate or the tear strength of the laminate is less than about 35%, or when the percentage decrease in the puncture resistance of the laminate is less than about 20%. For purposes herein, the percentage decrease in the physical properties of the laminate is determined according to formula (I):

[0031]

[0032] wherein the % decrease is the percentage decrease in the physical property; the initial property is the physical property measured according to a method under a set of conditions prior to gamma sterilization, which method in an embodiment is a standardized method; and the gamma property is the physical property measured according to the same method under the same conditions as used to obtain the initial property measurement after gamma sterilization at a dose of about 46 kiloGray or more.

[0033] For the purposes herein, unless otherwise stated, tensile strength is determined according to ISO 13934-1, as currently defined at the date of filing of this application, using the "strip method" variant of the method, or according to GB / T 3923.1-1997, also using the "strip method" variant. Tear strength is determined according to ISO 9073-4, as currently defined at the date of filing of this application, and puncture resistance is determined according to EN 863-1996, as currently defined at the date of filing of this application.

[0034] In an embodiment of the laminate of the present disclosure, the laminate comprises a microporous polyolefin membrane bonded to a nonwoven support or fabric comprising fibers having a sheath made of polyethylene and a core made of polyethylene terephthalate, which are bonded to each other in an embodiment using a discontinuous adhesive layer.

[0035] The nonwoven support of the laminate comprises a plurality of composite fibers or filaments having a core comprising or consisting essentially of polyethylene terephthalate and a sheath comprising or consisting essentially of polyethylene.

[0036] In an embodiment, the nonwoven support fibers are partially bonded to each other using an adhesive, and the microporous polyethylene film is laminated on the surface of the nonwoven support. In an embodiment, the microporous polyolefin film comprises polyethylene, and may include multiple layers. In other embodiments, the microporous polyolefin film is a single-layer microporous polyethylene film.

[0037] The laminate has barrier properties, at least partially resisting the intrusion of chemical and fluid contaminants, and further acting as a barrier to particulate penetration. The size, configuration and arrangement of the laminate allows vapor to pass through the microporous polyethylene film from the nonwoven support side, thereby providing a "breathable" barrier.

[0038] With reference to the accompanying drawings, Figure 1A and Figure 1B An embodiment of a laminate of the present disclosure is shown wherein the laminate 10 comprises a microporous polyolefin membrane 12 bonded to a nonwoven support 14, which in the embodiment shown are bonded to each other using a discontinuous adhesive layer, such as Figure 1A Section 46 and Figure 1B The nonwoven support 14 may be formed, for example, from spunbond filaments having a core comprising or consisting essentially of polyethylene terephthalate and a sheath comprising or consisting essentially of polyethylene.

[0039] In embodiments, the various layers of laminate 10 may be laminated, bonded, or attached together by a variety of methods, including thermomechanical bonding, ultrasonic bonding, adhesives, and the like. Figure 1A As shown, the laminate 10 has barrier properties that at least partially resist the intrusion of chemical contaminants, as shown at 52, and further acts as a barrier to the penetration of particulate matter, as shown at 48 and arrow 50. Also as shown Figure 1A As shown, the size, construction and arrangement of the laminate allows vapor 54 to pass through the microporous polyolefin membrane 12 from the nonwoven support 14 side, thereby providing a "breathable" barrier.

[0040] like Figure 2 As shown, for the purposes herein, a machine direction sample (MD) is obtained, wherein the longest axis is parallel to the machine direction of the nonwoven support. A cross direction sample (CD) is obtained, wherein the longest axis of the sample is perpendicular to the machine direction of the nonwoven support, parallel to the cross direction (CD) of the nonwoven support. It should be understood that for the purposes herein, in order to determine the tear strength in the machine direction (MD), the original tear or cut in the material required by the EN ISO 9073-4 method is actually oriented in the cross direction perpendicular to the longest axis of the sample. Similarly, when determining the tear strength of the laminate in the cross direction (CD), the original tear or cut in the material required by the EN ISO 9073-4 method is actually oriented in the machine direction perpendicular to the longest axis of the sample.

[0041] In some embodiments, the nonwoven support of the present disclosure can be formed by various known forming processes, in addition to spunbonding, air spraying, meltblowing or bonded carded web formation processes can also be included. For example, in one embodiment of the present disclosure, the nonwoven support is a spunbond nonwoven web consisting essentially of polyethylene / polyethylene terephthalate filaments, which has been found to be advantageous in forming laminates. Spunbond nonwoven webs are made of melt-spun filaments. As used herein, the term "melt-spun filaments" refers to small diameter fibers and / or filaments, which are formed by coextruding a first molten thermoplastic core material consisting essentially of polyethylene terephthalate and a second molten thermoplastic sheath material consisting essentially of polyethylene terephthalate, to form polyethylene / polyethylene terephthalate filaments from a plurality of thin, usually circular capillaries of a spinneret, and then rapidly reducing the diameter of the extruded filaments by, for example, non-eductive or jet fluid stretching or other well-known spunbond mechanisms. Finally, the melt-spun filaments are deposited in a substantially random manner onto a moving carrier belt or the like to form a web of substantially continuous and randomly arranged melt-spun filaments.

[0042] Microporous barrier membrane

[0043] Microporous polyolefin membrane can be top layer or bottom layer, and can be formed by any microporous membrane, and described microporous membrane can be suitably combined with or attached to nonwoven support, to produce the laminated product of the unique combination of performance characteristics and features described herein.A class of suitable microporous polyolefin membrane materials includes those materials comprising thermoplastic polyolefin polymer and filler.In embodiments, the polymer used to prepare microporous polyolefin membrane comprises polyethylene.In embodiments, the polymer used to prepare microporous polyolefin membrane is composed of polyethylene or is substantially composed of polyethylene.

[0044] In an embodiment, the polyolefin polymer and filler (and other) components can be mixed together, heated, and then extruded into a monolayer or multilayer film using any of a variety of film production processes known to those of ordinary skill in the art of film processing. Such film manufacturing processes include, for example, cast-embossed, cooled and flat cast, and blown film processes.

[0045] Typically, based on the gross weight of the film, on a dry weight basis, the microporous polyolefin film comprises about 30 wt % to about 60 wt % of a thermoplastic polyolefin polymer or its blend, and about 40 wt % to about 70 wt % of a filler. Other additives and ingredients can be added to the microporous polyolefin film, as long as they do not significantly interfere with the ability of the film layer to play a role according to the present disclosure. Such additives and ingredients can include, for example, antioxidants, stabilizers, antistatic particles and colorants. In addition to the polyolefin polymer, the microporous polyolefin film can also include fillers. As used herein, "filler" refers to particles and other forms of materials that can be added to the polyolefin extrusion blend, which do not produce chemical interference to the extruded film, but can be evenly dispersed throughout the film.

[0046] Microporous polyethylene films suitable for use herein include those having a weight per unit area of ​​from about 13 GSM to about 30 GSM.

[0047] In an embodiment, the adhesive is present at about 0.5 g / m 2 To about 5g / m 2 , or about 2g / m 2 About 4g / m 2 , or about 2.8g / m 2 To about 3.2g / m 2 In embodiments, the adhesive is applied as a continuous layer. In other embodiments, the adhesive is applied as a discontinuous layer or pattern. In embodiments, the adhesive comprises polyurethane, polyolefin or a combination thereof. In embodiments, the adhesive is a hot melt polyolefin glue.

[0048] In an embodiment, the weight of the nonwoven support, expressed as grams per square meter (GSM) weight, is less than about 40 g / m 2 , or less than about 38 g / m 2 , or less than about 35g / m 2 , or about 30g / m 2 About 40g / m 2 .

[0049] In an embodiment, the weight of the laminate (expressed in grams per square meter (GSM) weight) is at least 40 g / m 2 .

[0050] In embodiments, the laminate has a transverse tensile strength of about 40 N / 50 cm or more, or about 50 N / 50 cm or more, or about 60 N / 50 cm or more, when measured according to ISO 13934-1 after gamma sterilization at a dose of up to 46 kG or more.

[0051] In an embodiment, the laminate has a tensile strength in the machine direction of about 65 N / 50 cm or more, or about 80 N / 50 cm or more, or about 100 N / 50 cm or more, or about 110 N / 50 cm or more, or about 120 N / 50 cm or more, when measured according to ISO 13934-1 after gamma sterilization at a dose of up to 46 kG or more.

[0052] In embodiments, the laminate has a transverse tear strength of about 40 N or more, or about 50 N or more, or about 60 N or more, or about 65 N or more, when measured according to ISO 9073-4 after gamma sterilization at a dose of up to 46 kGy or more.

[0053] In embodiments, the laminate has a tear strength in the machine direction of about 15 N or more, or about 20 N or more, or about 25 N or more, or about 30 N or more, when measured according to ISO 9073-4 after gamma sterilization at a dose of up to 46 kG or more.

[0054] In embodiments, the laminate has a puncture resistance of about 5 N or more when measured according to EN863-1996 after gamma sterilization at a dose of up to 46 kGy or more.

[0055] In an embodiment, the laminate has a percent decrease in transverse tensile strength of about 30% or less, or about 20% or less, or about 10% or less, or about 5% or less, when measured according to formula (I), wherein the % decrease is the percent decrease in transverse tensile strength, the initial property being the transverse tensile strength measured according to ISO 13934-1 before gamma sterilization; and the gamma property is the transverse tensile strength measured according to ISO 13934-1 after gamma sterilization at a dose of up to 46 kGy or more.

[0056] In an embodiment, the percent decrease in tensile strength in the machine direction of the laminate measured according to formula (I) is about 30% or less, or about 28% or less, or about 25% or less, wherein the % decrease is the percent decrease in tensile strength in the machine direction, the initial property is the tensile strength in the machine direction measured according to ISO 13934-1 before gamma sterilization; and the gamma property is the tensile strength in the machine direction measured according to ISO 13934-1 after gamma sterilization at a dose of up to 46 kGy or more.

[0057] In an embodiment, the laminate has a percent reduction in transverse tear strength of about 40% or less, or about 20% or less, or about 10% or less, or about 5% or less, when measured according to formula (I), wherein the % reduction is the percent reduction in transverse tear strength, the initial property is the transverse tear strength measured according to ISO 9073-4 before gamma sterilization; and the gamma property is the transverse tear strength measured according to ISO 9073-4 after gamma sterilization at a dose of up to 46 kGy or more.

[0058] In an embodiment, the percent reduction in tear strength in the machine direction of the laminate measured according to formula (I) is about 60% or less, or about 40% or less, or about 15% or less, or about 5% or less, wherein the % reduction is the percent reduction in tear strength in the machine direction, the initial property is the tear strength in the machine direction measured according to ISO 9073-4 before gamma sterilization; and the gamma property is the tear strength in the machine direction measured according to ISO 9073-4 after gamma sterilization at a dose of up to 46 kGy or more.

[0059] In an embodiment, the percentage decrease in puncture resistance of the laminate measured according to formula (I) is about 20% or less, or about 15% or less, or about 10% or less, or about 5% or less, wherein the % decrease is the percentage decrease in puncture resistance, the initial property is the puncture resistance measured according to EN 863-1996 before gamma sterilization; and the gamma property is the puncture resistance measured according to EN 863-1996 after gamma sterilization at a dose of up to 46 kiloGray.

[0060] The laminated articles of the present disclosure are suitable for use as Type 4B chemical and anti-infective garments when measured according to EN 14605:2005+A1:2009 and EN 14126-2003, as Type 5B chemical and anti-infective garments when measured according to EN ISO 13982-1:2004+A1:2010 and EN 14126-2003, and as Type 6B chemical and anti-infective garments when measured according to EN 13034:2005+A1:2009 and EN 14126-2003.

[0061] Figure 3 An embodiment of a protective garment (300) according to an embodiment of the present disclosure is shown. In some embodiments, the garment (300) is a disposable coverall having a hood (302) and a closable opening (304), such as a zipper or hook-and-loop fastener, that allows a user to put on and take off the garment (300). In other embodiments, the laminate is suitable for use as an apron, boot or shoe covers, jacket, lab coat, coverall, and / or similar product.

[0062] Implementation

[0063] This article covers the following implementations:

[0064] E1. A laminate comprising a microporous polyethylene film bonded to a nonwoven support, wherein the laminate is stable to gamma sterilization at doses up to 46 kilogray or more.

[0065] E2. A laminate according to embodiment E1, wherein the nonwoven support comprises a plurality of core-sheath composite fibers, wherein the core comprises polyethylene terephthalate, and wherein the sheath comprises polyethylene.

[0066] E3. A laminate according to embodiment E1 or E2, wherein the nonwoven support is a spunbond fabric formed from a plurality of core-sheath composite fibers having a polyethylene sheath and a polyethylene terephthalate core.

[0067] E4. The laminate according to embodiments E1 to E3, wherein the microporous polyethylene film is a single layer.

[0068] E5. A laminate according to embodiments E1 to E4, wherein the single layer of microporous polyethylene film is bonded to the single layer of nonwoven support with about 0.5 GSM to 5 GSM of adhesive.

[0069] E6. The laminate according to embodiments E1 to E5, wherein the adhesive is disposed as a discontinuous layer between the microporous polyethylene film and the nonwoven support.

[0070] E7. The laminate according to embodiments E1 to E6, having a density of at least 40 GSM or more.

[0071] E8. A laminate according to embodiments E1 to E7, wherein the laminate has a decrease in one or more physical properties including tensile strength, puncture resistance or tear strength by less than about 20% when measured according to formula (1):

[0072]

[0073] Wherein % decrease is the percentage decrease in the physical property;

[0074] Initial properties are physical properties measured according to a method under a set of conditions prior to gamma sterilization; and

[0075] Gamma properties are physical properties measured after gamma sterilization, under the same conditions and by the same method.

[0076] E9. A laminate according to embodiment E8, wherein the percentage decrease is a percentage decrease in transverse tensile strength of about 30% or less when measured according to formula (I):

[0077] Where % decrease is the percentage decrease in transverse tensile strength;

[0078] The initial property is the transverse tensile strength measured according to ISO 13934-1 before gamma sterilization; and

[0079] The gamma property is the transverse tensile strength measured after gamma sterilization according to ISO 13934-1.

[0080] E10. A laminate according to embodiments E8 to E9, wherein the percentage decrease is a percentage decrease in tensile strength in the machine direction of about 30% or less when measured according to formula (I):

[0081] Where %Drop is the percent drop in tensile strength in the machine direction;

[0082] The initial property is the tensile strength in the machine direction measured according to ISO 13934-1 before gamma sterilization; and

[0083] Gamma properties are tensile strength in the machine direction measured after gamma sterilization according to ISO 13934-1.

[0084] E11. A laminate according to embodiments E8 to E10, wherein the percentage reduction is a percentage reduction in transverse elongation at break of about 60% or less when measured according to formula (I):

[0085] Where % decrease is the percentage decrease in transverse elongation at break;

[0086] The initial property is the elongation at break in the transverse direction measured according to ISO 13934-1 before gamma sterilization; and

[0087] The gamma property is the elongation at break in the transverse direction measured after gamma sterilization according to ISO 13934-1.

[0088] E12. A laminate according to embodiments E8 to E11, wherein the percentage reduction is a percentage reduction in transverse tear strength of about 40% or less when measured according to formula (I):

[0089] Where % decrease is the percentage decrease in transverse tear strength;

[0090] The initial property is the transverse tear strength measured according to ISO 9073-4 before gamma sterilization; and

[0091] The gamma property is the transverse tear strength measured after gamma sterilization according to ISO 9073-4.

[0092] E13. A laminate according to embodiments E9 to E14, wherein the percentage reduction is a percentage reduction in tear strength in the machine direction of about 60% or less when measured according to formula (I):

[0093] Where % reduction is the percentage reduction in tear strength in the machine direction;

[0094] The initial property is the tear strength in the machine direction measured according to ISO 9073-4 before gamma sterilization; and

[0095] Gamma properties are tear strength in the machine direction measured after gamma sterilization according to ISO 9073-4.

[0096] E14. A laminate according to embodiments E8 to E13, wherein the percentage reduction is a percentage reduction in puncture resistance of about 20% or less when measured according to formula (I):

[0097] Where % decrease is the percentage decrease in puncture resistance;

[0098] The initial property is the puncture resistance measured according to EN 863-1996 before gamma sterilization; and

[0099] Gamma properties are puncture resistance measured after gamma sterilization according to EN 863-1996.

[0100] E15. The laminate according to embodiments E1 to E14, wherein the laminate has a transverse tensile strength of about 40 N / 50 cm or more after gamma sterilization when measured according to ISO 13934-1.

[0101] E16. The laminate according to embodiments E1 to E15, wherein the laminate has a tensile strength in the machine direction of about 65 N / 50 cm or more after gamma sterilization when measured according to ISO 13934-1.

[0102] E17. The laminate according to embodiments E1 to E16, wherein the laminate has a transverse tear strength of about 40 N or more after gamma sterilization when measured according to ISO 9073-4.

[0103] E18. The laminate according to embodiments E1 to E17, wherein the laminate has a tear strength in the machine direction of about 15 N or more after gamma sterilization when measured according to ISO 9073-4.

[0104] E19. The laminate according to embodiments E1 to E18, wherein the laminate has a puncture resistance of about 7 N or more after gamma sterilization when measured according to EN 863-1996.

[0105] E20. A laminate according to embodiments E1 to E19, wherein the laminate is formed by a single layer of microporous polyethylene film bonded to a nonwoven support layer with an SF arrangement, wherein S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene film.

[0106] E21. The laminate according to embodiments E1 to E19, wherein the laminate is formed from multiple layers of microporous polyethylene film, each layer of microporous polyethylene film being bonded to a nonwoven support layer by a discontinuous adhesive layer.

[0107] E22. A laminate according to embodiments E1 to E19, wherein the laminate is formed by multiple layers of microporous polyethylene membranes having an (FS)x arrangement, each layer of microporous polyethylene membrane being bonded to one or more layers of nonwoven support with an adhesive, wherein x is greater than 1, S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

[0108] E23. A laminate according to embodiments E1 to E19, wherein the laminate is formed by a microporous polyethylene film having a FSF arrangement bonded to more than one nonwoven support layer with an adhesive, wherein S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene film.

[0109] E24. A laminate according to embodiments E1 to E19, wherein the laminate is formed by a multilayer microporous polyethylene membrane having an SFS arrangement bonded to a nonwoven support layer with an adhesive, wherein S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

[0110] E25. A laminate according to embodiments E1 to E19, wherein the laminate is formed by multiple layers of microporous polyethylene membranes having a (FS)xFS arrangement, each layer of microporous polyethylene membranes being bonded to one or more layers of nonwoven support layers with an adhesive, wherein x is greater than 1, S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

[0111] E26. A laminate according to embodiments E1 to E19, wherein the laminate is formed by multiple layers of microporous polyethylene membranes having an S-(FS)x arrangement, each layer of microporous polyethylene membrane being bonded to one or more layers of a nonwoven support layer with an adhesive, wherein x is greater than 1, S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

[0112] E27. A laminate according to embodiments E1 to E19, wherein the laminate is formed by multiple layers of microporous polyethylene membranes having an arrangement of (FS)xF, each layer of microporous polyethylene membrane being bonded to one or more layers of nonwoven support with an adhesive, wherein x is greater than 1, S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

[0113] E28. A clean room garment comprising a laminate according to embodiments E1 to E27, wherein the clean room garment meets the requirements of Class II medical disposable protective clothing according to GB19082-2009 standard.

[0114] E29. A medical garment comprising a laminate according to embodiments E1 to E27, wherein the medical garment meets the requirements of Class II medical disposable protective clothing according to GB19082-2009 standard.

[0115] E30. A kit comprising a laminate according to embodiments E1 to E27.

[0116] E31. A type 4B chemical protective suit comprising a laminate according to embodiments E1 to E27.

[0117] E32. A type 5B chemical protective suit comprising a laminate according to embodiments E1 to E27.

[0118] E33. A type 6B chemical protective suit comprising a laminate according to embodiments E1 to E27.

[0119] Although the present disclosure has been described with reference to certain specific embodiments and examples, it will be appreciated that the present disclosure is capable of further modification. Therefore, this application is intended to cover any variation, use or adaptation of the present disclosure that follows its general principles, and includes deviations from the present disclosure that are within the scope of known or customary practice in the art to which the present disclosure belongs and that fall within the limits of the appended claims.

Claims

1. A laminate comprising a microporous polyethylene film bonded to a nonwoven support, wherein the laminate is stable to gamma sterilization at doses up to 46 kilograys or more, wherein the nonwoven support comprises a plurality of core-sheath composite fibers, wherein the core comprises polyethylene terephthalate, and wherein the sheath comprises polyethylene.

2. The laminate according to claim 1, wherein the nonwoven support is a spunbond fabric formed of a plurality of core-sheath composite fibers having a polyethylene sheath and a polyethylene terephthalate core.

3. The laminate of claim 1 wherein the microporous polyethylene film is a single layer.

4. The laminate of claim 1 wherein each layer of microporous polyethylene film is bonded to the nonwoven support with about 0.5 GSM to 5 GSM of adhesive.

5. The laminate of claim 4, wherein the adhesive is disposed as a discontinuous layer between the microporous polyethylene film and the nonwoven support.

6. The laminate of claim 1 having a density of at least 40 GSM.

7. The laminate of claim 1, wherein the laminate is formed from a single layer of microporous polyethylene film adhesively bonded to a nonwoven support layer having an SF arrangement, wherein S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene film.

8. The laminate of claim 1, wherein the laminate is formed from multiple layers of microporous polyethylene film, each layer of microporous polyethylene film being bonded to a nonwoven support layer by an adhesive.

9. The laminate of claim 1, wherein the laminate is formed from multiple layers of microporous polyethylene membrane having an arrangement of (FS)x, each layer of microporous polyethylene membrane being bonded to one or more layers of nonwoven support with an adhesive, wherein x is greater than 1, S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

10. The laminate of claim 1, wherein the laminate is formed of a microporous polyethylene film having a FSF arrangement adhesively bonded to more than one nonwoven support layer, wherein S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene film.

11. The laminate of claim 1 , wherein the laminate is formed of a multilayer microporous polyethylene film adhesively bonded to a nonwoven support layer having an SFS arrangement, wherein S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene film.

12. The laminate of claim 1, wherein the laminate is formed from multiple layers of microporous polyethylene membranes having a (FS)xFS arrangement, each layer of microporous polyethylene membranes being bonded to one or more layers of a nonwoven support layer with an adhesive, wherein x is greater than or equal to 1, S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

13. The laminate of claim 1, wherein the laminate is formed from multiple layers of microporous polyethylene membrane having an S-(FS)x arrangement, each layer of microporous polyethylene membrane being adhesively bonded to one or more layers of a nonwoven support layer, wherein x is greater than 1, S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

14. The laminate of claim 1, wherein the laminate is formed from multiple layers of microporous polyethylene membrane having an arrangement of (FS)xF, each layer of microporous polyethylene membrane being adhesively bonded to one or more layers of nonwoven support, wherein x is greater than 1, S represents the nonwoven support, the "-" symbol represents a discontinuous adhesive layer, and F represents the microporous polyethylene membrane.

15. A clean room garment comprising the laminate according to any one of claims 1 to 14.

16. A medical garment comprising the laminate according to any one of claims 1 to 14.

17. Work clothing comprising the laminate according to any one of claims 1 to 14.

18. A work suit according to claim 17, which is a chemical protective suit.

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