Warp-knitted spacer fabric

Abstract

A spacer fabric has two textile layers and spacer yarns that transversely connect the textile layers and where the yarns forming the textile layers are composed exclusively of a nonmetallic material. In addition, at least a first portion of the spacer yarns is composed of metallic yarn, and a weight of all metallic spacer yarns is between 40 and 96% relative to the total weight of the spacer fabric.

Claims

1. In a spacer fabric with two textile layers and spacer yarns that transversely connect the textile layers and where the yarns forming the textile layers are composed exclusively of a nonmetallic material, the improvement wherein at least a first portion of the spacer yarns is composed of metallic spacer yarns, a second portion of the spacer yarns is composed of nonmetallic polyethylene terephthalate, polyolefin, and/or polyamide spacer yarns, and a weight of all metallic spacer yarns is between 40 and 96% relative to the total weight of the spacer fabric.

2. The spacer fabric according to claim 1, wherein the weight of all of the metallic spacer yarns is between 60 and 90% relative to the total weight per unit of area of the fabric.

3. The spacer fabric according to claim 1, wherein the metallic spacer yarns are a metal wires.

4. The spacer fabric according to claim 1, wherein the metallic spacer yarns each have a diameter of between 0.03 and 0.3 mm.

5. The spacer fabric according to claim 1, wherein spacer yarns the second portion have a fineness in the range from 22 dtex to 950 dtex.

6. The spacer fabric according to claim 1, wherein the textile layers are formed by warp knitting.

7. The spacer fabric according to claim 1, wherein a ratio of the number of metallic spacer yarns to the number of nonmetallic spacer yarns is between 1:5 and 5:1.

8. The spacer fabric according to claim 1, wherein the metallic spacer yarns are composed of copper or a copper alloy.

9. The spacer fabric according to claim 1, wherein the metallic spacer yarns have a nonconductive core covered with a conductive coating.

10. The spacer fabric according to claim 1, wherein the fabric has a total thickness measured transversely of the textile layers of between 1 mm and 20 mm.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

(2) FIG. 1 shows a warp-knitted spacer fabric according to the invention;

(3) FIG. 2 is a detailed view of the warp-knitted spacer fabric according to FIG. 1; and

(4) FIGS. 3A to 3D show the warp-knitted spacer fabric according to the invention in a cross section with spacer yarns guided in different manners.

SPECIFIC DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows a warp-knitted spacer fabric with two textile layers 1 and spacer yarns 2a and 2b that transversely interconnect the textile layers 1. Both FIG. 1 and in particular the detail view of FIG. 2 show that the spacer yarns 2a and 2b are different. A first portion of the spacer yarns 2a is composed of a metallic yarn, with a brass metal wire being used in this case. In principle, however, the invention is not restricted to such an embodiment. In particular, metallic multifilaments or even metal strands can also be used. In addition, both copper and various types of copper alloy can be used as the material.

(6) A second portion of the spacer yarns 2b is not composed of metallic yarn, but of a monofilament made of plastic. Unlike metallic yarn, monofilaments made of plastic provide much greater restorative forces due to their deflection, so that the spacer fabric, in contrast to an embodiment with spacer yarns composed only of metal 2a, results in a substantially more elastic behavior of the warp-knitted spacer fabric. Polyethylene terephthalate (PET) is usually used as the plastic, but other typical materials such as various polyolefins, polyamide, and the like can also be employed.

(7) The mesh yarns 3 shown in FIG. 2 that form the textile layers 1 are composed exclusively of plastic, so the same materials can be used as for the plastic spacer yarns 2b.

(8) Accordingly, the textile layers 1 are transiently composed of polyethylene terephthalate. According to the invention, the metallic yarn is therefore used only for the spacer yarns 2a, so that high thermal and/or electrical conductivity is produced in the direction of thickness of the warp-knitted spacer fabric or in the direction the textile layers 1 are spaced from each other. The formation of the textile layers 1 exclusively from mesh yarns composed of plastic, on the other hand, results in near perfect thermal and/or electrical insulation in the direction of their parallel planes.

(9) Although the number of metallic spacer yarns 2a is comparatively small relative to all spacer and mesh yarns, these are decisively determinative for the total weight of the warp-knitted spacer fabric due to their high density. For instance, in the warp-knitted spacer fabric shown in FIGS. 1 and 2, the portion of all of the metallic spacer yarns 2a constitutes 90% of the weight relative to the total weight of the warp-knitted spacer fabric.

(10) The weight of the warp-knitted spacer fabric can be determined on the one hand by the number and on the other hand by the thickness of the metallic spacer yarns 2a. In the embodiment shown in FIG. 2, the metal wires used as metallic yarns have a diameter of 0.2 mm. The fineness of the plastic monofilament for the plastic spacer yarns 2b is 240 dtex. The mesh yarns 3 of the textile layers 1 have a fineness of 76 dtex. However, these numbers are merely exemplary; for example, it is also possible for the diameter of the metallic yarns to be reduced while the fineness of the metallic yarns 3 and/or plastic spacer yarns 2b to be increased, in which case the weight proportion of the metallic yarn decreases overall.

(11) As already mentioned above, the electrical and/or thermal conductivity and also the elastic behavior of the spacer fabric can be set in a targeted manner via the ratio of the metallic spacer yarns 2a to the plastic spacer yarns 2b. This can be achieved in a knitting process by using two different guide bars for the spacer yarn composed of metallic yarn 2a and for the spacer yarn composed of plastic 2b. These guide bars have a multitude of warp guides that are arranged next to one another, each warp guide carrying a single yarn. It is therefore possible not to place a yarn on every warp guide; for example, a yarn can be provided only on every other yarn. A ratio of the metallic spacer yarns 2a to the plastic spacer yarns 2b of 1:1 is achieved, for example, by covering each warp guide of the two guide bars with a corresponding metallic yarn or monofilament made of polyethylene terephthalate. An example of such an embodiment is shown in FIG. 3a. As an alternative, it is also possible even with the ratio remaining the same for only every other warp guide to be occupied alternately both in the guide bars for the metallic spacer yarns 2a and in the guide bar for the plastic spacer yarns 2b, so that the individual spacer yarns 2a and 2b alternate so as to be spaced apart from one another.

(12) FIGS. 3B to 3D show embodiments that differ from this. For example, in the warp-knitted spacer fabric shown in FIG. 3B, only every other warp guide is occupied with a spacer yarn composed of plastic 2b, whereas the warp guides of the guide bar for the metallic spacer yarns 2a are all occupied.

(13) A configuration that is inverted in this respect is shown in FIG. 3C, in which only every other warp guide is occupied with a metallic yarn.

(14) FIG. 3D shows an embodiment in which both guide bars for the spacer yarns 3a, 3b are completely occupied. However, the thickness of the metallic yarn used for the spacer yarns composed of metal 2a is substantially greater than the thickness of the plastic spacer yarns 2b, so that, in terms of weight, a similar effect is achieved as with a numerical reduction of the plastic spacer yarns 2b according to FIG. 3B.

(15) The laying patterns shown as examples for a warp-knitted spacer fabric can in principle also be used for other spacer fabrics and are not limited to warp-knitted spacer fabrics.