Three-dimensional knit spacer fabric for footwear and backpacks

Abstract: A integrated three-dimensional knit spacer fabric is provided. The fabric includes a first fabric layer (13), a second fabric layer (15), and a resilient yarn (21) interconnecting the two layers. The first fabric layer is made from fiber rendered hydrophilic, while the second fabric layer is abrasion resistant.

Description: This invention relates to a three-dimensional knit or woven fabric for footwear and backpacks, and more particularly, to a three-dimensional knit or woven fabric having first and second fabric layers spaced from, and connected to, each other. Such a fabric is for example known from US 5 783 277 A. Prior art footwear and backpack fabrics are generally comprised of a non-integrated, composite fabric with a laminate applied thereto, the laminate acting as a moisture barrier, hindering transport and evaporation of moisture. Accordingly, it is desirable to provide a fabric which overcomes the above disadvantages. It is thus an object of the invention to provide an improved fabric construction for enhancing the transport of body fluids. Another object of the invention is to provide an improved three-dimensional fabric which is sufficiently resilient. Another object of the invention is to provide a three-dimensional fabric which functions as a spacer fabric. Still other objects and advantages of the invention will in part be obvious, and will in part be apparent from the following description. Summary Of The Invention Generally speaking, in accordance with the invention, an integrated composite three-dimensional knit spacer fabric is provided. The fabric includes a first fabric layer, a second fabric layer, and a resilient yarn interconnecting the two layers. The first fabric layer is made from fiber rendered hydrophilic, while the second fabric layer is abrasion resistant. The three-dimensional spacer fabric of the invention may be used for footwear and backpacks. In all uses, the fabric is constructed such that the bulk ratio of the stitch and pile yarns is controlled. It is significant that the knit fabric of the invention has a three-dimensional structure. Because of this construction, the fabric acts to cushion the load and protect the wearer. The invention will now be described in greater detail with reference to a preferred embodiment thereof and with the aid of the attached drawings, in which: FIG. 1 is a side elevational view showing the loop structure of the spacer fabric made in accordance with the invention; and FIG. 2 is a side view of the inventive spacer fabric showing the nap face of the top fabric layer. Detailed Description Of The Preferred Embodiment The double-face fabric of the invention may be prepared by knitting a three-dimensional knit fabric on a double-needle bar warp knitting machine commonly used in the manufacture of velvet and well known in the art. As shown in FIGS. 1 and 2, the three-dimensional knit spacer fabric is generally indicated at 11 and includes a first fabric layer 13 made from stitch yarn 17, a second fabric layer 15 made from stitch yarn 19, and pile yarn 21 interconnecting the two layers. In addition, knit fabric 11 includes backing or lay-in yarns 25 and 26 which are held by stitch yarns 17 and 19 respectively as shown. In preparing the three-dimensional knit fabric of the invention, the yarn that is used is preferably a synthetic material such as polyester, acrylic or nylon. The yarn may be filament or spun, textured or fully oriented. The yarn interconnecting the two layers of the inventive three-dimensional knit spacer fabric should have sufficient resilience and stiffness to keep the two fabric layers apart even if pressure is applied to any one of the fabric layers. In construction, the interconnecting pile yarn may be made of either the same or different material than that of the two fabric layers. Particularly, in order to render the interconnecting pile yarn resilient, the yarn may be made of a resilient material such as monofilament or multifilament polyester, nylon, etc. The fabric is designed to facilitate moisture transport away from the body, while maintaining a comfortable top layer and air circulation next to the skin. Top layer 13 is made from fibers rendered hydrophilic to make sure that all moisture is transported through it, thus keeping its surface dry. In particular, first fabric or top (back) layer 13 is made from a stitch yarn 17 having a fineness of between 300 and 600 denier and, in one embodiment, with an individual fiber fineness in the range of between 0.3 and 2.5 dpf (denier per Fiber). In one embodiment, the backing or lay-in yarn 25 of top layer 13 will be multifilament and will typically have a fineness of between 70 and 200 denier, with, typically, an individual fiber fineness of 0.5 to 5 dpf. Preferably, stitch yarn 17 and backing yarn 25 of first fabric layer 13 are made of polyester or nylon that has been rendered hydrophilic in order to enhance the transport of perspiration and thereby maintain the skin surface dry. Particularly, layer 13 is chemically treated or utilizes modified fibers so that it is rendered hydrophilic, as described in U.S. Patent No. 5,312,667. By using a chemically modified fiber or by chemically treating layer 13, the layer is rendered substantially hydrophilic. As a result, the transport of perspiration from the surface, especially if the yarn fibers of layer 13 are raised, as described hereinbelow, is substantially enhanced -- liquid moisture is made readily transportable along the surface of the yarn fibers of layer 13. Preferably, the surface of fabric layer 13 is sanded, brushed or napped and thus comprises a raised surface fabric, with each fiber end being a conductor of moisture. Thus, fabric layer 13 will include a plurality of fibers for conducting perspiration therealong from the skin of the wearer and eventually to second fabric layer 15, from where it is evaporated. Pile yarn 21 which interconnects the two layers may be a monofilament or multifilament yarn having a fineness of between 40 and 150 denier, and typically with an individual fiber fineness of 2 to 12 dpf when multifilament. It is preferred, however, that the pile yarn be monofilament in order to increase resilience. In one embodiment, the pile yarn is made from fiber rendered hydrophilic in order to facilitate the transport of moisture from top layer 13 to layer 15. Moreover, each of pile yarns 21 is sufficiently spaced from one another to allow air flow throughout fabric 11 -- this improves cushioning, ventilation and moisture vapor transmission as well as providing for physical protection from objects such as pebbles. Outside or back fabric layer 15 is made from stitch yarn 19 which is preferably coarser than the stitch yarn in the first layer. In one embodiment, yarn 19 will have a fineness of 150 to 300 denier with typically an individual fiber fineness of 3.0 to 12 dpf. Backing or lay-in yarn 26 typically will also have a fineness of from 150 to 300 denier with typically an individual fiber fineness of 3.0 to 12 dpf. Both stitch yarn 19 and backing yarn 26 will either be multi- or monofilament, with a high tenacity value in order to increase toughness. In particular, at least one of, and preferably each of, the yarns 19 and 26 will have a tenacity of between about 3 and 12 grams, preferably about 6 and 12 grams, per denier. This level of tenacity improves abrasion, tear and rupture resistance of fabric layer 15. Optionally, the fabric of the invention may incorporate an elastomeric yarn such as LYCRA in one or both of lay-in yarns 25 and 26 of layers 13 and 15 respectively. Such wrap yarn will typically have a total fineness of between about 70 denier and 200 denier of wrap LYCRA. This will enhance the softness and flexibility of the layers, and the tightness of fit. The elastomeric yarn may also be added to the stitch yarn of each layer. It will thus be seen that the objects set forth above, and those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the constructions described above without departing from the scope of the invention, it is intended that all matter contained in this description shall be interpreted as illustrative and not in a limiting sense. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which come as a matter of language, might be said to fall therebetween.

Claims: A three-dimensional spacer fabric comprising a first fabric layer (13) made from a first stitch yarn (17) and a first backing yam (25) and a second fabric layer (15) made from a second stitch yam (19) and a second backing yarn (26), wherein the first and second layers are interconnected via a resilient pile yam (21) having a fineness of between 40 and 150 denier; characterised in that the first and second fabric layers (13,15) are different, wherein at least one of said first stitch yam (17) and said first backing yarn (15) has been rendered hydrophilic, at least one of said second stitch yarn (19) and said second backing yarn (26) has a tenacity of between 0.26 and about 1.06 N/tex (between about 3 and 12 grams per denier), and said first stitch yarn has a fineness of between 300 and 600 denier. A fabric as claimed in Claim 1, wherein said first fabric layer (13) has a surface with yarn fibres that are raised. A fabric as claimed in Claim 2, wherein said fibers are raised by one of sanding, napping or brushing. A fabric as claimed in any one of the preceding claims, characterised in that at least one of the yams of said first layer (13) is chemically treated to render the yarn hydrophilic. A fabric as claimed in any one of the preceding claims characterised in that said second stitch yarn (19) has a fineness of between about 150 and 300 denier and a tenacity of between about 0.26 and about 1.06 N/tex (between about 3 and 12 grams per denier). A fabric as claimed in any one of the preceding claims characterised in that the stitch yarn (17, 19) is coarser in the second layer (15) than in the first layer (13). A fabric as claimed in any one of the preceding claims characterised in that said pile yam (21) is monofilament. A fabric as claimed in any one of the preceding claims characterised in that at least one of said backing yarns (25,26) includes an elastomeric yam incorporated therein. A fabric as claimed in any one of the preceding claims characterised in that said pile yarn (21) is sufficiently spaced in order to allow air flow through the fabric. A fabric as claimed in any one of the preceding claims characterised in that said first stitch yam (17) has an individual fiber fineness in an amount between about 0.3 and 2.5 dpf. A fabric as claimed in any one of the preceding claims characterised in that said first backing yarn (25) has a fineness of between about 70 and 200 denier. A fabric as claimed in any one of the preceding claims characterised in that said first backing yam (25) has an individual fiber fineness of between about 0.5 and 5 dpf. A fabric as claimed in any one of the preceding claims characterised in that said pile yarn (21) had an individual fiber fineness of between about 2 and 12 dpf when multifilament. A fabric as claimed in any one of the preceding claims characterised in that said pile yarn (21) is rendered hydrophilic in order to facilitate the transport of moisture from between said first fabric layer (13) and said second fabric layer (15). A fabric as claimed in any one of the preceding claims characterised in that both said second stitch yarn (19) and said second backing yarn (26) have a fineness of between about 150 and 300 denier. A fabric as claimed in any one of the preceding claims characterised in that each of said second stitch yam (19) and said second backing yarn (26) have an individual fiber fineness of between about 3.0 and 12 dpf.

Inventors: LOHMUELLER KARL, ROCK MOSHE, LOHMUELLER, KARL, ROCK, MOSHE
Applicants: MALDEN MILLS IND INC, MALDEN MILLS INDUSTRIES, INC.
Application year: 1998
Main classification: D04B21
IPC codes: D04B21