Weather Resistant Insulative Apparel Fabrics

Abstract

A conformable and optionally elastic weather resistant, comfortable fabric provides wind and rain resistance, plus thermal insulation, along with moisture transfer through the fabric, by combining a hydrophobic and dense outer layer with a bulky absorbent middle layer and a thin hydrophobic inner layer, joined by stitching and optionally subsequently shrinking to bulk the structure and re-adjust the openings formed by stitching. The third hydrophobic layer may be omitted and substituted with hydrophobic underlap yarns formed during the stitching process. The method provides high conformability and optionally elastic fit or inelastic pre-adjustable body fit.

Claims

1. A weather resistant and insulative stitched fabric comprising a hydrophobic, water and wind-resistant outer layer along a technical front, a hydrophilic, fibrous middle layer, and a hydrophobic, open inner layer along a technical back, wherein at least the outer and middle layers are stitched with stitching yarns, wherein the outer layer has an initial Frazier air permeability value under about 5 ft.sup.3/ft.sup.2/minute, wherein the open inner layer has planar openings exposing a lower surface of the middle layer, wherein at least some of the fibers of the middle layer are projected at least through the inner layer through the stitching perforations, and wherein said projected fibers are capable of wicking moisture from below the inner layer through the middle layer and out of the outer layer, and wherein an overall density of the stitched fabric is lower than about 0.25 g/cm.sup.3.

2. The stitched fabric of claim 1, wherein the open inner layer comprises underlap yarns originating from the stitching yarns along the technical back.

3. The stitched fabric of claim 1, wherein the stitching yarns are shrinkable and arranged along a machine direction (MD).

4. The stitched fabric of claim 1, wherein the middle layer includes absorbent or non-absorbent, virgin or reclaimed waste fibers of various lengths, deniers and orientations.

5. The stitched fabric of claim 2, wherein the underlap yarns originate from laid-in yarns.

6. The stitched fabric of claim 5, wherein the laid-in yarns are POY yarns, and the stitched fabric is shrunk in a cross direction (XD) by at least 10%.

7. The stitched fabric of claim 5, wherein the shrinkable stitched-in or laid-in yarns are elastic yarns, and the stitched fabric is shrunk in the MD or XD or both by at least 10%, and the stitched fabric is elastic in the MD or XD or both.

8. The stitched fabric of claim 7, wherein the bulked stitched fabric is capable of partially stretching in the MD or XD or both without a substantially loss of thickness.

9. The stitched fabric of claim 1, wherein the outer face layer comprises a plexi-filamentary nonwoven layer.

10. The stitched fabric of claim 1, wherein the outer face layer comprises a reinforced or nonreinforced polymeric film.

11. The stitched fabric of claim 1, wherein the face layer is printed.

12. The stitched fabric of claim 1, wherein the middle layer contains up to about 20% of high-melting fibers in the range from about 3 to about 15 dpf and from about 1.5 to about 4.0-inch cut length.

13. The stitched fabric of claim 12, wherein said high melting fibers have a melting point higher than that of all components of the stitched fabric.

14. The stitched fabric of claim 1 further comprising stitched holes without stitching yarns.

15. The stitched fabric of claim 1, wherein the middle layer contains up to 20% of low-melt single component fibers or bicomponent adhesive fibers providing a fiber content in the range from about 2% to about 15% that can melt at temperatures under about 200° C.

16. The stitched fabric of claim 1, wherein the stitching yarns comprise shrinkable yarns and yarns that have a melting point lower than all components of the stitched fabric.

17. The stitched fabric of claim 1, wherein the middle layer comprises a needle-punched felt.

18. The stitched fabric of claim 16, wherein at least some of the fibers from the middle layer are inserted into the inner layer between the stitching perforations, and wherein said inserted fibers are capable of wicking moisture from below the inner layer through the middle layer and out of the outer layer.

19. The stitched fabric of claim 1, wherein at least some of the fibers from the middle layer are pre-inserted into the inner layer, and wherein said inserted fibers are capable of wicking moisture from below the inner layer through the middle layer and out of the outer layer.

20. The stitched fabric of claim 1, wherein the stitched fabric is shrunk with heat or steam by at least about 10% in the MD or XD or both.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

[0045] FIG. 1A is a schematic of a cross section of three superposed layers, including a dense or solid hydrophobic fabric serving as the outer layer, a bulky absorbent mid-layer, and a low weight, highly open hydrophobic fabric or mesh serving as the inner layer.

[0046] FIG. 1B is a schematic representation of the three layers of FIG. 1A after stitching.

[0047] FIG. 1C is a schematic representation of the stitched layers of FIG. 1B after shrinking.

[0048] FIG. 2A is a schematic of a dense outer layer superposed over an absorbent bulky layer.

[0049] FIG. 2B is a schematic of the superposed layers of FIG. 2A after stitching and forming an under-layer of underlaps.

[0050] FIG. 2C is a schematic of the stitched composite of FIG. 2B after shrinking.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] In one embodiment, a thin, hydrophobic and durable film or fabric with high resistance to wind and water serves as the outer layer of a stich-bonded comfort apparel fabric on the technical front. Preferably, this outer layer has a Frazier air permeability (FAP) values under 5 ft.sup.3/ft.sup.2/min, preferably under about 2.5 ft.sup.3/ft.sup.2/minute, and optionally approaching 0 ft.sup.3/ft.sup.2/minute or no air permeability. Nonwoven fabrics and their FAB values are discussed in U.S. Pat. No. 5,368,920, which is incorporated herein by reference in its entirety. The '920 patent discloses several examples of fabrics and their FAB values. For example, spunbonded nonwoven fabrics made from continuous fibers with bond distance of 0.38 mm and 0.09 mm have FAB values of 850 and 300-500 ft.sup.3/ft.sup.2/minute, respectively. A thermal bonded nonwoven of 1.5 denier and 1.5 inch fibers with 0.09 mm bond distance has a FAP value of 300 ft.sup.3/ft.sup.2/minute, and a hydroentangled nonwoven of 1.5 denier and 1.5 inch fibers with bond distance of 0.06 mm bond distance has a FAP value of 460 ft.sup.3/ft.sup.2/minute. Hence, the outer layer with FAP values from 0-5 ft.sup.3/ft.sup.2/minute has very low to no air permeability. The outer layer provides the inventive stitch-bonded fabric its high resistance to wind and rain. As used herein, the outer layer's FAP value does not include any modifications to increase the FAP values, such as perforations caused by stitch-bonding needles with stitching yarns or without yarns, as discussed below.

[0052] The outer layer is placed against a relatively loose, bulky and hydrophilic fibrous middle layer with a density under 0.25 g/cm.sup.3, preferably under 2.0 g/cm.sup.3 or 0.15 g/cm.sup.3, more preferably 0.10 g/cm.sup.3, and containing a high percentage of absorptive cellulosic fibers.

[0053] Preferably, a third layer or an inner layer is positioned on the opposite side of the middle layer. In one embodiment, a protective thin, open and hydrophobic fabric, such as a woven or knit mesh fabric or a low-weight nonwoven fabric, is placed against the opposite side of absorbent mid-layer and serves as the inner face of the composite garment fabric, which would be facing the wearer of the garment, along the technical back. The FAP value of the inner repellent fabric is preferably over 15 ft.sup.3/ft.sup.2/min. The two or three superposed layers, i.e., the thin outer hydrophobic wind/water resistant layer, the middle absorbent, hydrophilic bulky layer and the protective thin, open hydrophobic inner layer, are stitched using linear “chain” or tricot stitches. The stitching yarns are preferably elastically or inelastically shrinkable yarns. The shrinkable elastic yarns are preferably deployed under high tension. Alternatively, the stitching yarns are partially oriented shrinkable yarns (POY), also fed under tension. The inner fabric may be post-shrinkable eliminating the need of using shrinkable yarns. Some of the absorbent fibers from the absorptive, hydrophilic mid-layer are partially pushed through the highly open inner layer at the stitch insertion points by the stitching needles, establishing a path for body moisture to be wicked outward through the perforations opened by the stitching needles in the wind-resistant face or outer layer.

[0054] In another embodiment, laid-in or stitched-in underlaps serve as the hydrophobic inner open layer. The relatively loose absorbent fibers of the absorbent mid-layer are highly exposed to or protrude partially below the laid-in underlaps between the yarn insertion points. The generally absorbent and loose bulky middle layer can advantageously include absorbent or nonabsorbent, long or short, high or low denier fibers enclosed and protected by the two surrounding layers.

[0055] The stitched fabric is optionally allowed to shrink with or without added heat as the stitched or laid-in yarns or the shrinkable inner layer shrinks. The shrinkable yarns also tighten around the loose absorbent fibers, and also around the sections of the outer layer between stitch slits, as well as around the inner layer or around the laid-in or stitched-in underlap yarn layer. The stitched fabric is capable of attracting moisture through the open hydrophobic inner layer into the absorbent mid-layer and out through the stitch openings or perforations of the outer layer, aided by the absorbent fibers partially forced through the inner layer by the action of the stitching needles.

[0056] Preferably and optionally the laid-in or stitched-in underlaps are also formed with shrinkable and are either elastic or POY yarns. The shrinkage is also optionally two-directional along the surface of the inventive fabrics.

[0057] The laid-in yarns or underlaps tend to stay in-plane and shrink in-plane, allowing the formation of a relatively flat and smooth inner surface with the ends of the absorbent fibers from the middle layer projecting through. When a non-shrinking lower open fabric is used and the assembly is shrunk using shrinkable yarns, the lower surface will assume a wavy texture.

[0058] In one embodiment, the technical front outer layer or face face is a plexi-filamentary microfiber nonwoven fabric. Alternatively, the outer layer is a dense and hydrophobic bonded or spunlaced nonwoven. In one embodiment, the outer layer is a thin and soft polymeric film or a polymeric membrane. In one embodiment, the outer layer is a thin polymeric film reinforced with a thin nonwoven, knit or woven fabric or a layer of bi-directionally oriented staple or filament fibers.

[0059] In another embodiment, the absorbent, hydrophilic, fibrous mid-layer is a lightly needle-punched cross-lapped layer of absorbent fibers such as Rayon or Lyocell. The absorbent fibrous layer may contain up to 25% low melting fibers that are activated after the stitched fabric is shrunk. The absorbent layer may also contain a relatively small percentage of resilient high denier absorbent or nonabsorbent fibers helping to maintain bulk. In one embodiment, the absorbent layer contains up to 25% low-melting fibers melting at a temperature below the melting temperature of the rest of the components in the stitched fabric including the inner fabric or laid-in stitched yarns. In one embodiment, the stitching yarns are a composite of elastic and low melting yarns melting at a temperature below the melting temperature of the rest of the components in the fabric. The middle layer can be any mixture or combination of fibers with a density under about 0.2 g/cm.sup.3, preferably under about 0.15 g/cm.sup.3 or under about 0.10 g/cm.sup.3, a thickness of at least about 2 mm, preferably at least about 2.5 mm or at least about 3 mm, with a basis weight from about 50 to about 150 g/m.sup.2, preferably from about 75 g/m.sup.2 to about 125 g/m.sup.2. Preferably, it contains at least 50 wt. % plant based or cellulosic fibers with a length of at least 20 mm. Preferably, the mid-layer is a lightly needle-punched felt. The envelopment of the absorbent, hydrophilic mid-layer by the outer and inner layers also provides the opportunity to use a small percentage of higher melting, higher denier stiff fibers that can help maintain the bulk, and do not soften and collapse with moisture without creating a roughness on either outer and inner surface. In instances where a small percentage of absorbent fibers such as rayon or lyocell fibers are pre-driven from the middle layer through the open inner layer, the denier of the absorbent fibers is kept substantially lower, and the pre-inserting punching needles relatively fine to avoid the insertion of high-denier stiff fiber ends through the inner layer towards the wearer.

[0060] In one embodiment, the inner layer is non-shrinkable or less shrinkable than the stitching yarn system, and the inner layer is buckled and textured offering interrupted contact against the wearer's body and higher comfort. The two levels of shrinkage can be balanced to maintain flatness or produce and adjust texture and three-dimensionality along the bottom.

[0061] In another embodiment, a buckled, textured surface of the inner layer is optionally flattened with heat. In one embodiment a flat back-face is lightly touched with a heated there-dimensional tool to create a textured surface. Alternatively, the inner side of the fabric is heat-finished by passing a heated roller having a smooth or patterned face over the buckled, textured inner layer, to stabilize the inner layer and the entire fabric without affecting the outer face layer which, as in the case of plexi-filamentary polyethylene, has a low melting or deformation temperature.

[0062] Referring an exemplary inventive stitched fabric shown in FIG. 1A, a dense hydrophobic layer 101 forming the outer layer is laid over bulky absorbent mid-layer 102 containing fibers 105. A hydrophobic, water repellent and highly air permeable open inner layer 103 then is then placed under the absorbent mid-layer 102. Referring to FIG. 1B, the three layers are stitched with yarns 104 as the stitch needles first enter the dense wind/water resistant layer 101. Some of the ends 106 of absorbent fibers 105 of the middle absorbent layer 102 are driven through at the stitching perforations 107 by the stitching needles and protrude beyond the highly open inner layer 103. Additionally, fibers 108 along the bottom of the mid-layer 102 are exposed through the openings of the lower open inner layer 103 between the stitched yarns/lines 104.

[0063] Referring to FIG. 1C, the stitching yarns 104 are shrunk with heat pinching the three layers 101, 102 and 103 and bulking the composite stitched fabric. The bulking process and the pressure of shrinking stitching yarns promotes further penetration of fiber ends 106 through the open inner layer 103.

[0064] Referring to the right-hand side of FIGS. 1A, 1B and 1C, limited amount and length of fibers 108 from middle layer 102 or from a separate absorbent layer similar to layer 102 may optionally be pre-inserted through the lower layer 103 in advance, e.g., by needle-punching, before the layering and stitching to further facilitate moisture pick up all along the entire interface. The needle-punching is preferably performed with finer needles to selectively drive in finer absorbent fibers such as rayon or lyocell, and to avoid driving higher denier stiff high-melt fibers such as polyester, to avoid inner surface roughness.

[0065] Referring to FIGS. 2A and 2B, the inner layer is formed in situ with underlaps 210 of stitching hydrophobic yarns, eliminating the need for adding a third fabric inner layer under outer wind/rain resistant layer 201 and bulky, absorbent mid-layer 202 with fibers 205. The two layers are stitched using preferably shrinkable linear “chain” or “pillar” or tricot stitches. The shrinkable yarns are preferably elastic and fed under tension. Alternatively, the stitching yarns are partially oriented shrinkable yarns (POY) also fed under tension. Underlaps 210 may be originating from the same stitch pattern as the yarn loops 211 holding the layers, or they may be laid-in, originating from a different stitching bar. The linear loops 211 or the underlaps 210 or both may be shrinkable, elastic or inelastic depending upon the need to bulk, tighten or elasticize the composite fabric. Along the stitched lines 204, fibers 206 from mid-layer 202 are driven beyond the lower surface. Fibers 208 of mid-layer 202 may also protrude through underlaps 201 between stitched lines 204, as shown.

[0066] As shown in FIG. 2C, the stitched assembly is optionally and preferably shrunk in one or both directions to increase bulk and durability. This also allows a larger amount or length of fibers 206 from the absorbent layer 202 to proceed beyond the underlap layer 210.

[0067] In all embodiments with two or three superposed layers, the option of flattening or texturing the lower surface by retouching with a heated flat or textured tool is available.

EXAMPLE 1

[0068] OUTER LAYER: Tyvek type 800, 1.2 oz/yd.sup.2 (32.7 g/m.sup.2) on the technical front as the hydrophobic, dense, outer layer. (Tyvek™ flash-spun polyethylene plexi-filament layer. Tyvek 800 is typically used to make disposable, chemical resistant protective coveralls, wind and rain resistant apparel, wind resistant house-wraps and similar products).

[0069] MIDDLE LAYER: Rayon 3-dpf 2.0-inch cut, carded/cross lapped into a 2.5 oz/yd.sup.2 (84.75 g/m.sup.2) lightly needle-punched layer as the middle layer. (Rayon is a manufactured fiber made from natural sources such as wood and agricultural products that are regenerated as cellulose fiber.)

[0070] INNER LAYER: Sontara style 8034 spunlaced polyethylene terephthalate (PET) on the technical back with a basis weight of 0.75 oz/yd.sup.2 (25.4 g/m.sup.2).

[0071] The three layers were stitched with 150-denier POY PET polyester, 14 gage 1-miss two or effectively 14/3 gage or 0.21 inch between stitches in XD, and 8 CPI or 0.125 inch between penetrations in MD, using a chain stitch pattern 10-01, and high tension. The stitched product had an overall thickness of about 1.2 mm and a basis weight of 4.4 oz/yd.sup.2 (149.2 g/m.sup.2), resulting in an overall calculated density of 0.125 gram/cm.sup.3.

[0072] Subjected to one cycle of washing and drying on “hot” settings, the product shrunk by a ratio of 1.5:1 in MD and 1.1:1 in XD to a basis weight of 7.2 oz/yd.sup.2 (244.1 g/m.sup.2). The bulked washed thickness was approximately 3.2 mm, and the overall calculated density was 0.08 g/cm.sup.3. Unless noted otherwise, all washing and drying in the Examples herein were conducted on “hot” settings.

[0073] After 5 more washing/drying cycles, there was no indication of surface wear and no further change in bulk.

[0074] The plexi-filamentary face of the technical front resisted water penetration as stitched, and to a much higher degree after bulking. The polyester PET face on the technical back absorbed water and transferred it to the middle absorbent layer without leaving a wet feel on the inner surface.

EXAMPLE 2

[0075] Same as Example 1, except that there was a polyester tricot knit fabric approximately 18 gage and 18 CPI, weighing approximately 2.0 oz/yd.sup.2 (67.8 g/m.sup.2) was used as the outer layer.

[0076] The stitched basis weight was 5.8 oz/yd.sup.2 (196.6 g/m.sup.2); the stitched thickness was 1.6 mm, and the stitched density was 0.124 g/cm.sup.3. After one wash-dry cycle, the shrinkage was 1.3:1 in MD and the basis weight increased to 7.5 oz/yd.sup.2 (254.3 g/m.sup.2). The thickness increased to 2.9 mm, and the calculated density decreased to 0.09 g/cm.sup.3.After 5 wash-dry cycles, the final properties were similar or substantially the same as to those of Example 1, with particularly excellent durability on both surfaces.

EXAMPLE 3

[0077] Same as Example 1, but without a third inner layer on the technical back.

[0078] Laid-in 150-denier textured PET yarns with a 00-44 pattern were deployed on the technical back adding a weight of about 0.35 oz/yd.sup.2 (11.9 g/m.sup.2), and resulting in a total stitched weight of 4.0 oz/yd.sup.2 (135.6 g/m.sup.2), and a calculated density of 0.11 g/cm.sup.3.

[0079] After washing and MD shrinkage by about 1.4:1, the final basis weight was 5.6 oz/yd.sup.2 (189.8 g/m.sup.2); the final thickness was 3.3 mm; and the final density was 0.06 g/cm.sup.3.

[0080] Compared to the wavy backsides in Examples 1 and 2, the technical back face was essentially flat after shrinking, and the product was softer and more pliable.

[0081] All other properties were similar to those in Examples 1 and 2.

EXAMPLE 4

[0082] Same as Example 2 with the knit inner layer, except with Lycra/PET 70/50 stitching yarn instead of PET POY yarn. The stitched basis weight was 5.7 oz/yd.sup.2 (193.2 g/m.sup.2) and the thickness was 1.4 mm.

[0083] After 1 wash-dry cycle and shrinkage in MD of 1.4:1, the basis weight was 7.6 oz/yd.sup.2 and the thickness was 3.0 mm. The density was 0.08 g/cm.sup.3 with at least 40% elastic stretch.

EXAMPLE 5

[0084] Same as Example 3, except that the chain stitching yarns were 70 denier Lycra yarns wrapped with 50 denier PET, deployed under tension.

[0085] As stitched and under MD tension to prevent shrinking, the basis weight was 3.8 oz/yd.sup.2 (128.8 g/m.sup.2); the thickness was 1.1 mm; and the density was 0.12 g/cm.sup.3.

[0086] After 1 wash-dry cycle, the fabric shrunk 2:1 in MD, the basis weight was 7.6 oz/yd.sup.2 (257.6 g/m.sup.2); the thickness increased to 3.2 mm; and the density decreased to 0.08 g/cm.sup.3.

[0087] There was no further change after 5 wash-dry cycles.

[0088] The shrunk and bulked product was elastically stretchable by 100% in MD. Furthermore, when the product was stretched by 50% to a basis weight of about 5.7 oz/yd.sup.2 (193.2 g/m.sup.2), the thickness remained at the same 3.2 mm and at a density under 0.06 g/cm.sup.3, offering high heat insulation value when used in form-fitting apparel and stretches locally during wear.

[0089] This example shows one of the novel features of the present invention, i.e., after bulking and shrinking the stitched fabric can be partially stretched and sewn into a wind/rain resistant fabric that can locally stretched during wear to provide improved fitting as well as insulation to the wearers.

[0090] As used herein, DPF or denier per filament is the weight in grams of 9,000 meters of yarns/fibers. Gage is the needle spacing across per inch in XD and CPI is the number of needle penetrations per inch in MD. As used herein, the density values in the examples are calculated.

[0091] While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives stated above, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. One such modification is that, in addition to a dense face layer, a bulky absorbent layer, and an open inner layer, any shrinkable or non-shrinkable layers can be placed between the two outer layers, and the assembly stitched with a combination of elastic or non-elastic shrinkable or non-shrinkable yarns, with optional added stitching bars of low melt fibers, low-melt yarns and added laid in stitches, to selectively adjust additional properties such as durability, bulk resilience, or abrasion resistance. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.