Spacer fabric and uses

Abstract

To provide a spacer fabric which has high abrasion resistance on the one hand, and can be used for various kinds of interior materials on the other hand, and which can be inexpensively and easily manufactured. [Solution] A spacer fabric having a first flat knitted layer 1, a second flat knitted layer 2, and a spacer yarn 3 connecting these knitted layers, wherein the first knitted layer 1 is formed of a first and a second yarn system and has wales extending in the production direction and courses extending in the transverse direction, in which the first yarn system is formed as a chain stitch structure, the yarns of the second yarn system are guided through at least two adjacent wales alternately, offset in alternating order along the production direction without stitch formation, and the yarns of the first yarn system have a larger count than the spacer yarn 3.

Description

[Technical field]

[0001] The present invention relates to a spacer fabric having a first flat knitted layer, a second flat knitted layer and spacer yarns connecting the knitted layers, the first knitted layer being formed from at least a first and a second yarn system and having wales extending in the production direction and courses extending in the transverse direction. [Background technology]

[0002] Spacer fabrics are characterized on the one hand by their lightweight and breathable structure and on the other hand by their elastic properties in the thickness direction due to the spacer yarns extending between the two flat knitted layers, which allows them to be applied as a soft, elastic, air-circulating layer, for example, in mattresses, upholstery furniture, clothing or shoes. Furthermore, spacer fabrics are also becoming more widespread in the automotive sector as technical textiles (knits) for use as elastic intermediate layers in air-conditioning seats, seat covers or interior trim parts.

[0003] Spacer fabrics as intermediate layers forming interior trim for motor vehicles are known from US Pat. No. 5,399,633, in particular for the use of spacer fabrics for airbags or airbag flaps at a number of locations, which provide a reduced tear strength.

[0004] Furthermore, especially in the automotive industry, it is becoming increasingly interesting to use spacer fabrics not only as intermediate layers, but also directly as decorative layers. Thus, for example, Patent Document 2 describes spacer fabrics that directly form the surface of interior parts or seat covers. In this case, in order to achieve high resistance, the spacer yarns in the first knitted layer form stitches by yarn interlacing, while the spacer yarns in the second knitted layer do not form stitches but are knitted there simply as a weft thread. Furthermore, a hole structure in the second knitted layer can be provided, which hole structure is expediently covered by the weft thread on the inside of the second knitted layer. Such a hole structure is usually achieved via a fillet lace knitting structure, so that relatively large and clearly visible individual holes are usually obtained from a plurality of stitches.

[0005] However, in known spacer fabrics, there is a risk that individual threads may pull out under mechanical load when used as a decorative layer, resulting in visual and functional impairment of the spacer fabric, especially when the spacer fabric is exposed to sharp objects or hook-and-loop fasteners, which are often used in clothing.

[0006] To check the hook-and-loop resistance of textiles, they are actually subjected to a so-called hook-and-loop test, by which the sensitivity to abrasive loads by hook-and-loop fasteners is checked in a realistic manner. For this purpose, the German Association of the Automotive Industry (VDA) published the test specification VDA230-210 dated December 2008. After loading of the measurement sample by the hook-and-loop fastener, an evaluation is carried out by visual inspection and an assessment is made on a 5-point scale. If the surface changes are small, a rating of 5 is given, whereas a complete destruction of the surface and structure is assessed by a rating of 1. To be suitable for permanent use in motor vehicles, the above-mentioned test specification requires at least a rating of 4, which cannot be easily achieved with the known spacer fabrics, so that vehicle seats are usually always equipped with an additional cover layer made of fabric, leather or artificial leather (faux leather).

[0007] The above-mentioned Patent Document 2 has already basically demonstrated resistance to hook-and-loop fasteners, but due to the relatively large hole structure, it can only be flexibly used as an interior material to a limited extent. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] German Patent No. 102010010524 [Patent Document 2] DE 102012105134 A1 [Non-patent literature]

[0009] [Non-Patent Document 1] "Textile Fertigungsverfahren-Eine Einfuehrung", by Gries et al., page 411, 3rd edition Summary of the Invention [Problem to be solved by the invention]

[0010] Against this background, the problem underlying the present invention is to provide a spacer fabric which, on the one hand, has high abrasion resistance and, on the other hand, can be used in various types of interior materials, is inexpensive and easy to manufacture. [Means for solving the problem]

[0011] The above object is achieved by a spacer fabric according to claim 1. It is essential to the invention that the first yarn system is configured as a chain stitch structure and the yarns of the second yarn system are arranged to be guided alternately through at least two adjacent wales M in an offset alternating sequence along the production direction P without stitch formation, the yarns of the first yarn system having a higher (yarn) count than the spacer yarns.

[0012] According to this configuration, the hole structure of the first knitted layer is not achieved through a fillet lace structure. Rather, the first knitted layer is formed essentially through a classic chain stitch structure, with the threads running along the wales, respectively. In order to nevertheless obtain a certain degree of hole formation, a second thread system is provided, which is guided alternately through at least two adjacent wales as a kind of weft thread without stitch formation. The hole formation is then achieved by the threads of the second thread system being offset in an alternating sequence. This means that the threads are guided from the central wale alternately through the left and right wales adjacent thereto, which causes the first thread system to be pulled (flexed) to a certain degree. In this case, the sequence 3-2-3-1-2-1 is generated from three adjacent wales, with the central wale being designated number 2. In the first thread system, the threads in each course are fixed to a certain degree through the stitches by using a chain stitch structure, so that the threads of the first thread system are not easily pulled out even when the hook-and-loop fastener is in operation.

[0013] It contributes to hook-and-loop resistance that the yarns of the first thread system have a larger thread count than the spacer yarns so that the first thread system can have a somewhat larger spacer yarn and therefore the spacer yarns are not easily captured by an acting hook-and-loop fastener.

[0014] In this context, the yarn count of a textile yarn is a measure of its weight relative to its length. The yarn count is also called denier (see non-patent document 1). A yarn with a higher count or denier has a higher weight and usually also a higher thickness than a yarn with a lower count. The higher thickness of the yarns of the first yarn system therefore ensures that the yarns have a certain flat extension in the area outside the hole structure so that the hook-and-loop fastener can only penetrate to a limited extent into the surface of the first knitted layer.

[0015] Thus, overall, two separate systems for hook-and-loop resistance are considered independently of each other. On the one hand, the first knitted layer itself has a certain degree of hook-and-loop resistance, so that the individual threads, in particular of the first thread system, are not easily pulled out, which would adversely affect the visual appearance. This is achieved by the chain knit structure of the first thread system. In this context, it is also expedient if the threads of the first thread system are made of a material that is only slightly bulging, in particular multifilament yarns, and therefore have no excess volume or only a small excess volume that can be pulled out by the action of the hook-and-loop fastener.

[0016] On the other hand, however, the penetration of the hook-and-loop fasteners into the spacer fabric and the entrapment of the spacer threads should also be prevented, since this would lead to local compression of the spacer fabric, which could likewise be disadvantageous both visually and functionally. This is achieved in particular by a relatively small, finely structured hole structure, which further allows for easier structural adaptation to different applications as interior materials.

[0017] According to a preferred embodiment of the invention, the ratio of the counts of the yarns of the first yarn system to the spacer yarns is at least 1.5:1, particularly preferably 2:1, very particularly preferably at least 3:1, whereby the counts of the individual yarns are usually stated in dtex (decitex), the yarns of the first yarn system preferably having a count of 100 to 300 dtex (decitex), preferably 150 to 200 dtex (decitex).

[0018] According to a preferred development of the invention, the threads of the first thread system also have a higher count than the threads of the second thread system, the ratio being preferably at least 2:1, preferably at least 3:1, very particularly preferably at least 4:1. Such a configuration ensures that the threads of the second system are likewise protected by the threads of the first thread system by the withdrawal by the acting hook-and-loop fastener. Since the threads of the first thread system are decisive for the formation of the hole structure due to their offset arrangement, the withdrawal of the individual threads results in the hole structure not being able to be maintained over the entire surface of the first knitted layer. This can decisively worsen the visual appearance, in particular because, due to the uniform structure of the spacer fabric, individual damage is easily visible from the outside to the user or consumer and can be perceived as particularly defective.

[0019] Preferably, the yarn count of the second yarn system is between 15 and 100 dtex, preferably between 20 and 60 dtex. Basically, different yarn types can be used as yarns for both the first and the second yarn system, preferably the yarns of the first yarn system being formed of multifilament yarns and the yarns of the second yarn system being formed of monofilament yarns. The use of multifilament yarns for the chain stitch structure in the first knitted layer results in a particularly fluffy and soft surface. Furthermore, multifilament yarns are characterized by a small bending strength, so that stitch formation can be carried out without significant restoring forces. In contrast, multifilament yarns for the second yarn system are not necessary, since they do not or essentially do not contribute to the weaving of the surface of the first knitted layer. Furthermore, monofilaments are characterized by a relatively large bending strength, so that it is possible to form the hole structure already mentioned above by tightening the individual stitches of the first yarn system.

[0020] According to one preferred development of the invention, the first thread system is formed by a guide bar and the second thread system is formed by a guide bar with 1-in-1-out threading.

[0021] Although it is basically possible to achieve already a sufficiently high hook-and-loop resistance by using the first and second yarn systems in the first knitted layer, according to a particularly preferred configuration, the first knitted layer is further provided with a third yarn system, which is formed as an offset tricot knit structure. In a tricot knit structure, the yarns are guided through two adjacent wales in an alternating offset manner, with stitch formation in each course. This therefore essentially distinguishes the third yarn system from the second yarn system, in which the yarns are guided only as weft yarns without stitch formation in courses in the production direction. However, according to the second yarn system, and now due to the offset arrangement, the yarns of the third yarn system are guided through at least two wales that are alternately adjacent to each other in a correspondingly offset manner in an alternating sequence. Preferably, the yarns of the third yarn system form stitches where the yarns of the second yarn system are guided around the wales. Thus, essentially a simultaneous running of the yarns of the second and third thread systems in the production direction P occurs, with both thread systems being differentiated only by the stitch formation or by the absence of stitch formation. The yarns are fixed by the stitch formation of the third thread system and therefore cannot be easily pulled out of the first knitted layer. This serves the yarns as a kind of cover for the second thread system, which can essentially be pulled out more easily than the yarns of the third thread system due to the construction without stitch formation. By means of the cover, it can be achieved that the yarns of the second and third thread systems are simultaneously captured when the hook-and-loop fastener penetrates, and the yarns of the third thread system, due to the absence of excess volume, fix not only themselves but also the yarns of the second thread system to the knitted layer. Furthermore, by the incorporation of the third thread system with the offset tricot structure, it is possible to close the hole structure to some extent against the penetration of dust or dirt.

[0022] Preferably, the third yarn system is formed of two guide bars with a 1-in-1-out threading. Furthermore, the yarns of the third yarn system are preferably flat yarns. By flat yarns is understood yarns that are essentially wrinkle-free, which means that the length is not subsequently stretched or is essentially not stretched and therefore has no or only little excess volume between the individual stitches.

[0023] According to one preferred configuration, the knitted layer and / or the spacer yarns are made of polyester, in particular polyethylene terephthalate (PET).

[0024] Furthermore, the multifilament yarns of the first yarn system preferably comprise 24 to 96 filaments. A suitable multifilament yarn may have, for example, 30 to 80 filaments. As the number of filaments increases, the material becomes softer, while as the number of filaments decreases, the compressive stiffness and resistance of the multifilament yarn to mechanical damage increases.

[0025] In order to achieve a particularly attractive and preferably uniform color impression in the textile structure of the knitted fabric layers and the spacer yarns, the multifilament yarns of at least the first textile layer and the spacer yarns, and preferably also the yarns of the second textile layer, are not only colored in the same shade but also similarly, with solution-dyed multifilament yarns being particularly preferred.

[0026] In the case of solution-dyed multifilament yarns, the colorant (dye) is added directly during the production of the individual filaments of polymeric material in the form of a masterbatch. The individual filaments are then completely and uniformly dyed. The color tone does not change even upon mechanical damage, abrasion or the like, at most with changes in the surface properties. Thus, solution-dyed materials do not particularly fade over time, and the colorant in the polymer matrix is ​​also protected against environmental influences, such as bleaching.

[0027] However, besides solution-dyed multifilament yarns, other methods are not fundamentally excluded according to the invention.

[0028] The spacer fabric according to the invention is characterized by a high resistance to mechanical loads. According to a preferred configuration of the invention, the spacer fabric is characterized by having a hook-and-loop resistance of at least a rating of 4 according to the hook-and-loop test according to VDA 230-210, when the hook-and-loop test is carried out on the exposed surface of the first knitted layer. Preferably, a rating of 5 is achieved.

[0029] Due to its resistance, the spacer fabric according to the invention can also be used in the high load range as a textile cover layer. In addition, however, the spacer fabric has the elastic return properties typical of spacer fabrics and a lightweight, open and breathable structure. For the above mentioned applications, the total thickness can be, for example, 2.5-8 mm, although the invention is not limited to this preferred range.

[0030] The subject of the present invention is also an interior furnishing, such as a seat covering for a motor vehicle or an interior furnishing for a motor vehicle, which has the above-mentioned spacer fabric as a covering material or decorative layer. Another variant is the seats or interior furnishings of, for example, an aircraft or a vehicle on rails, such as a train, a subway or the like. In aircraft, there is an effort to use seats that are as light and space-saving as possible, on the one hand, to reduce the flight weight, and on the other hand, to provide enough space for as many passengers as possible. Furthermore, the interior furnishings can be furniture, such as seating furniture.

[0031] The first knitted layer then forms a surface of the interior furnishing, i.e. in particular a surface of a motor vehicle or motor vehicle interior furnishing, where hook and loop fasteners or other rough or sharp objects are at least less likely to damage the surface of the interior furnishing due to the increased resistance.

[0032] Thus, the spacer fabric according to the invention provides another function by virtue of its resistive surface, while maintaining another advantage, namely elastic recovery properties and breathability. In particular, according to the invention, it is possible to adapt and optimize the resistive, elastic properties and breathability properties according to the respective requirements.

[0033] The present invention will be described in detail below with reference to examples. [Brief description of the drawings]

[0034] [Figure 1] FIG. 2 is a schematic diagram of a spacer fabric according to the present invention; [Diagram 2] FIG. 2 is a plan view of a first knitted layer of a spacer fabric according to the present invention. [Diagram 3] FIG. 2 shows a schematic of the yarn system of the first knitted layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] In Fig. 1 a spacer fabric is shown diagrammatically with a first flat knitted layer 1 and a second flat knitted layer 2 connected to each other by a spacer yarn 3. It can further be seen from Fig. 1 that the first flat knitted layer 1 is provided with a hole structure with openings 4. Said hole structure 4 is not generated by a fillet lace knit structure, as in spacer fabrics known from the prior art, but rather via a classical chain knit structure, the construction of the first flat knitted layer 1 being shown in detail in Fig. 2.

[0036] According to this, the first knitted fabric layer 1 is composed of a first yarn system 5 and a second yarn system 6, and further comprises wales M extending in the production direction P and courses R extending laterally.

[0037] It is essential to the invention that the first yarn system 5 is formed as a chain stitch structure and the yarns of the second yarn system 6 are arranged to be guided alternately through at least two adjacent wales M offset in alternating order along the production direction P without stitch formation, the yarns of the first yarn system 5 having a higher (yarn) count than the spacer yarns 3.

[0038] The progression of the individual thread systems 5, 6 can be seen clearly, especially in comparison with FIG. 3. For the first thread system 5, a classic chain stitch structure with open chain stitches is provided, which run only along the wales M. The second thread system 6 runs entirely along three adjacent wales M, with the threads always turning over two adjacent wales M in alternating order. This results in the individual chain stitches of the first thread system 5 being pulled alternately to the left and right in the production direction P, forming a hole structure with the openings 4 shown in FIG. 2. The threads of the second thread system 6 then run in a zigzag manner.

[0039] The yarns of the first yarn system 5 have a higher yarn count compared to the second yarn system 6 and compared to the spacer yarns 3, and therefore contribute the majority of the material at the surface of the first woven (knitted) fabric layer 1. This makes it difficult for the hooks of the hook and loop fastener to penetrate, thus improving the hook and loop fastener resistance of the surface.

[0040] 2 and 3, it is further evident that a third thread system 7 is also provided, which runs in common with the second thread system 6 but, unlike the second thread system, is connected to the individual wales M via respective stitches, thus resulting in an offset tricot knit structure which, on the one hand, contributes to the stability of the second thread system 6 and, on the other hand, covers to a certain extent the openings 4 and thus protects them from the ingress of dirt or dust.

[0041] Furthermore, all yarn systems 5, 6, 7 of the first knitted layer 1 are made of polyester, in particular polyethylene terephthalate. This also applies to the spacer yarns 3 and to the second woven (knitted) knitted layer 2.

Claims

1. A spacer fabric having a first flat knitted layer (1), a second flat knitted layer (2), and spacer yarns (3) connecting these knitted layers, wherein the first knitted layer (1) is formed of at least first and second yarn systems (5, 6), and has a wale (M) extending in the production direction (P) and a course (R) extending in the transverse direction. In the spacer fabric, the first yarn system (5) is formed as a chain stitch structure, the yarns of the second yarn system (6) are offset in an alternating order along the production direction (P) without forming stitches and are guided through at least two wales (M) adjacent to each other alternately, and the yarns of the first yarn system (5) have a larger count than the spacer yarns (3). The spacer fabric is characterized by this.

2. The spacer fabric according to claim 1, characterized in that the ratio of the count of the yarns of the first yarn system (5) to the spacer yarns (3) is at least 1.5:

1.

3. The spacer fabric according to claim 1 or 2, characterized in that the yarns of the first yarn system (5) have a count of 100 to 300 dtex (decitex), preferably 150 to 200 dtex (decitex).

4. The spacer fabric according to claim 1 or 2, characterized in that the yarns of the second yarn system (6) have a count of 15 to 100 dtex (decitex), preferably 20 to 60 dtex (decitex).

5. The spacer fabric according to claim 1 or 2, characterized in that the first yarn system (5) is formed by a guide bar, and the second yarn system (6) is formed by a guide bar passing through one in and one out.

6. The spacer fabric according to claim 1 or 2, characterized in that the first knitted layer (1) includes a third yarn system (7) formed as an offset tricot stitch structure.

7. The spacer fabric according to claim 6, characterized in that the third yarn system (7) is formed by a guide bar passing through one in and one out.

8. The spacer fabric according to claim 6, characterized in that the yarns of the third yarn system (7) are formed of flat yarns.

9. The spacer fabric according to claim 1 or 2, characterized in that the knitted fabric layers (1, 2) and the spacer yarn (3) are made of polyester, in particular polyethylene terephthalate (PET).

10. The spacer fabric according to claim 1 or 2, characterized in that it has a hook-and-loop fastener resistance of at least rating 4 according to the surface fastener test in accordance with VDA 230-210.

11. An interior fitting, in particular a seat covering material for a motor vehicle with a motor or an interior fitting material for a motor vehicle with a motor, characterized in that it has the spacer fabric according to claim 1 or 2 as a covering material.

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