Spacer fabric

Abstract

A spacer fabric has a first flat warp-knitted fabric layer having openings each formed by a respective plurality of stitches and a second flat warp-knitted fabric layer also having openings that are each formed by a respective plurality of stitches. The second warp-knitted fabric layer further has at least a first yarn system and a second yarn system and yarns of the first yarn system run in a production direction on exactly over respective stitch wale and yarns of the second yarn system extend over at least two adjacent stitch wales that run in the production direction. The openings are larger than one of the stitches or a space between two of the stitches. Spacer yarns interconnect the warp-knitted fabric layers.

Claims

1. A composite spacer fabric comprises: a first flat warp-knitted fabric layer having openings each formed by a respective plurality of stitches; a second flat warp-knitted fabric layer also having openings that are each formed by a respective plurality of stitches, the second warp-knitted fabric layer further having a first yarn system with yarns running in a production direction over exactly one respective stitch wale; and a second yarn system with yarns extending over at least two adjacent stitch wales that run in the production direction, the openings of the fabric layers being larger than one of the stitches or the space between two of the stitches, the second yarn system being formed as a filet knit or net structure having a first partial yarn system and a complementary second partial yarn system, and stretch of the composite spacer fabric as determined in accordance with DIN EN ISO 13934-1 at a tension of 25 N in the first flat warp-knitted fabric layer being between 25% and 60% in the production direction and a transverse direction that is transverse to the production direction, stretch of the composite spacer fabric also determined in accordance with DIN EN ISO 13934-1 at a tension of 25 N in the second flat warp-knitted fabric layer being between 1.5% and 10% in the production transverse directions; and spacer yarns interconnecting the warp-knitted fabric layers.

2. The composite spacer fabric according to claim 1, wherein, the yarns of the second yarn system alternately form pillar stitches in the production direction and form stitches selected from the group of tricot, cord, satin, velvet, and atlas.

3. The composite spacer fabric according to claim 1, wherein the two partial yarn systems are formed by two guide bars each with a feed of 1 full, 1 empty or a feed of 2 full, 2 empty.

4. The composite spacer fabric according to claim 1, wherein the yarns of the first yarn system alternately form pillar stitches in the production direction.

5. The composite spacer fabric according to claim 1, wherein the first flat warp-knitted fabric layer has greater stretchability in the production direction and a transverse directions than the second warp-knitted fabric layer.

6. The composite spacer fabric according to claim 1, wherein stretch of the composite spacer fabric as determined in accordance with DIN EN ISO 13934-1 at a tension of 25N are at least twice as large for the first flat warp-knitted fabric layer as for the second flat warp-knitted fabric layer in the production direction and the transverse direction.

7. The composite spacer fabric according to claim 1, wherein a thickness of the composite spacer fabric is between 2 and 20 mm.

8. The composite spacer fabric according to claim 1, wherein the second warp-knitted fabric layer is formed by multifilament smooth yarns and/or monofilament yarns.

9. The composite spacer fabric according to claim 1, wherein the second warp-knitted fabric layer is formed by textured multifilament yarns.

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 is a perspective section through a composite according to the invention having a spacer fabric and a decorative cover layer that are sewn together;

(3) FIG. 2 is a section through the decorative cover layer and the spacer fabric before and after sewing;

(4) FIG. 3 is a view like FIG. 1 with an additional spacer fabric as an air distribution layer;

(5) FIG. 4 shows a second warp-knitted fabric layer of the spacer fabric;

(6) FIG. 5 shows a first warp-knitted fabric layer of the spacer fabric;

(7) FIG. 6 shows the knitting pattern for a second yarn system of the first warp-knitted fabric layer;

(8) FIG. 7 shows the knitting pattern of a first yarn system of the first warp-knitted fabric layer having an second partial yarn system and a first partial yarn system; and

(9) FIGS. 8A and 8B are views like FIG. 1 showing alternative embodiments of the composite.

SPECIFIC DESCRIPTION OF THE INVENTION

(10) FIG. 1 shows a composite that forms the uppermost layers of a vehicle seat, for example a car seat. The composite comprises a spacer fabric 1 that, as usual, extends along a production direction P and a transverse direction Q perpendicular to it. The embodiment of the spacer fabric 1 is further explained below with reference to the production direction P and the transverse direction Q. The production direction P is also referred to as the knitting direction or the longitudinal direction due to the production method.

(11) The spacer fabric 1 has a first flat warp-knitted fabric layer 2, a second flat warp-knitted fabric layer 3 and spacer threads 4 interconnecting the warp-knitted fabric layers 2, 3. In the case of the two flat warp-knitted fabric layers 2, 3, stitch wales extends along in the production direction P and stitch courses in the transverse direction Q. In the warp-knitting process, the stitches of a stitch course are formed at the same time with respective guide bars, the individual yarns running in the production direction P with their respective knitting pattern, that is to say possibly with an offset between the individual stitch wales.

(12) The spacer threads 4 connect the two warp-knitted fabric layers 2, 3 and are responsible for pressure-elastic restoring properties of the spacer fabric 1 when compressed in the direction of the thickness. Monofilament yarn is preferably provided for the spacer threads 4 in order to obtain good elastic properties. The compression hardness can be determined by the yarn material, the density of the spacer threads 4 and their thickness.

(13) According to FIG. 1, a decorative cover layer 5 is provided on the first warp-knitted fabric layer 2, it being particularly preferably leather or synthetic leather. In principle, however, film materials, textiles, or the like are also conceivable. In the decorative cover layer 5 made of leather or synthetic leather shown in FIG. 1, a perforation 6 is provided in order to allow a ventilation function to be described in more detail below.

(14) In order to achieve a particularly high-quality design of the composite, the spacer fabric 1 has compressed areas 7 where the spacer fabric 1 is permanently at least partially compressed for structuring the decorative cover layer 5. In the compressed areas 7, the decorative cover layer 5 is sewn to the spacer fabric 1 with the incorporation of the second warp-knitted fabric layer 3, each with a decorative yarn 8, so that connections 9 between the decorative cover layer 5 and the second warp-knitted fabric layer 3 are formed by the decorative yarns 8.

(15) From FIG. 1, it can also be recognized that the spacer fabric 1 is compressed to less than 50% of its thickness in the uncompressed state in the compressed areas 7.

(16) In the embodiment according to FIG. 1, the compressed areas 7 extend parallel to one another, so that a rib pattern arises. The spacing between adjacent compressed areas 7 with respect to the respective center can typically be between 15 mm and 100 mm.

(17) In the following, further possible patterns of the compressed areas are presented, with the most varied types of patterns and composites also being considered, of course. In particular, a seat surface can be designed by combining different patterns or pattern portions according to the technical requirements and aesthetic requirements.

(18) According to FIG. 1, the spacer fabric 1 is pressed in at the first warp-knitted fabric layer 2 at the compressed areas 7, while the second warp-knitted fabric layer 3 lies in one plane. FIG. 1 is idealized in this regard, such asymmetrical behavior is the subject of the invention and also leads to the three-dimensional design of the decorative cover layer 5 being clearly and permanently revealed.

(19) This behavior is achieved in the scope of the invention in that the first warp-knitted fabric layer 2 facing the decorative cover layer 5 has greater stretchability in the production direction P and in the transverse direction Q than the second warp-knitted fabric layer 3. If, therefore, the decorative cover layer 5 is pulled at the connections 9 formed by the decorative yarns 8 at the compressed areas 7 in the direction of the second warp-knitted fabric layer 3, the first warp-knitted fabric layer 2 can easily deform and in particular stretch there, whereas, due to the higher strength or lower stretchability of the second warp-knitted fabric layer 3, there is less deformation.

(20) The restoring forces generated by the spacer threads 4 straighten the decorative cover layer 5 between the compressed areas 7, thereby also creating a tensile load on the second warp-knitted fabric layer 3 in the plane. Due to the low stretchability of the second warp-knitted fabric layer 3, these tension can be absorbed.

(21) Due to the different stretching properties and in particular the low stretchability of the second warp-knitted fabric layer 3, the decorative cover layer 5 can be stretched open to a certain extent by the restoring forces of the entire spacer fabric 1.

(22) It should be taken into account that in the sense of the invention the term stretchability refers to the stretch at a predetermined tension that causes no damage and preferably also no substantial reversible changes in the spacer fabric 1 and in particular in the two warp-knitted fabric layers 2, 3.

(23) The stretchability for the production direction P and the transverse direction Q can be determined for example in accordance with DIN EN ISO 13934-1 at a tension of 25 N. For such a test, strips with a width of 50 mm can be cut from the spacer fabric, the initial length then being marked on the spacer fabric 1, with which the clamping is subsequently provided in a corresponding test device. In order then to be able to test the two flat warp-knitted fabric layers 2, 3 individually, the spacer threads 4 can be cut by an incision made parallel to the warp-knitted fabric layers 2, 3. The influence of the remaining remnants of the spacer threads 4 in the two flat warp-knitted fabric layers 2, 3 is neglected and actually only plays a subordinate role for the stretchability. The patterns thus formed, that is to say strips running in the production direction Por transverse direction Q depending on the test, are then subjected to a tension of 25 N, the increase in length then being determined in percent. Usually, a significantly greater stretch of the first flat warp-knitted fabric layer 2 compared to the second flat warp-knitted fabric layer 3 is observed according to the invention. The ratio is at least 2:1, but can readily be 3:1, 5:1, 7:1, or even 10:1 and more.

(24) For example, for the production direction P and the transverse direction Q, the stretch determined in the manner described for a tension of 25 N in the first flat warp-knitted fabric layer 2 can be between 25% and 60%. Such good stretchability ensures that the first warp-knitted fabric layer 2 can be easily pressed in at the connections 9. In particular, due to the good stretchability, there is practically no substantial force distribution along the first warp-knitted fabric layer 2.

(25) The second flat warp-knitted fabric layer 3 has a significantly lower stretch in the production direction P and transverse direction Q with a tension of 25 N and a test according to DIN EN ISO 13934-1. The stretch can be for example between 1.5% and 10%, in particular between 2% and 7%. This slight stretch ensures that the second warp-knitted fabric layer 3, as shown in FIG. 1, is only slightly deformed and thus can stretch open the decorative cover layer 5.

(26) Finally, FIG. 1 also shows that the decorative cover layer 5 can be connected to the first warp-knitted fabric layer 2 by positive substance jointing, in particular by adhesive 10 that also facilitates the production process.

(27) The properties of the spacer fabric 1 described above can also be illustrated in FIG. 2 that shows the composite before and after sewing only in one section.

(28) Before the corresponding connections 9 are generated by the decorative yarns 8 on the compressed areas 7, the decorative cover layers 5 and the spacer fabric 1 are substantially flat. If the compressed areas 7 are then generated with a spacing L from one another relative to the respective center, this length Lis retained at the second warp-knitted fabric layer 3, while the first warp-knitted fabric layer 2 can be extended in an arc shape due to its good stretchability.

(29) The measures for generating the different stretch behavior with regard to the first warp-knitted fabric layer 2 and the second warp-knitted fabric layer 3 are explained in more detail below.

(30) FIG. 3 shows a further development of the composite, the decorative cover layer 5 with the spacer fabric 1 being provided on an additional air distribution layer 11. The air distribution layer 11 can also be formed by a further spacer fabric, the air distribution layer 11 being provided for the distribution of cooling air in the plane. For this purpose, the air distribution layer 11 is connected to a ventilation device (not shown), for example a blower.

(31) Air for cooling and air conditioning a user can then be blown out through the spacer fabric 1 and the perforation 6 of the decorative cover layer 5. In this context in particular, the compressed areas 7 can also be particularly advantageous with regard to user comfort, because the blown-in air can be circulated or discharged through the ribs formed in this way. Against this background, very good air permeability in the thickness direction is also advantageous for the spacer fabric 1.

(32) FIG. 4 shows the embodiment of the first warp-knitted fabric layer 2 by way of example that has good stretchability. The first warp-knitted fabric layer 2 has a filet pattern (i.e. a miss-lapping or net-like structure), so that the first warp-knitted fabric layer 2 has openings 12 each formed by a plurality of stitches. The filet pattern is usually formed with two guide bars, wherein the openings 12 also provide good stretchability of the first warp-knitted fabric layer 2.

(33) In order to further improve these properties, relatively low yarn tension can also be used in the knitting process for the first warp-knitted fabric layer 2.

(34) Furthermore, the first warp-knitted fabric layer 2 can also be formed from textured multifilament yarn that is not only particularly soft but also elastically stretchable to a certain extent along its longitudinal direction due to the textured structure. This also applies in particular when the first warp-knitted fabric layer 2 and preferably the entire spacer fabric 1 is formed from an inelastic thermoplastic polymer such as a polyester, polyamide, or polyolefin.

(35) FIG. 5 shows a view of the second warp-knitted fabric layer 3 that also has openings 12. Even if FIGS. 4 and 5 are not to scale with respect to one another, it can already be seen from a comparison of the stitch size that the openings 12 of the second warp-knitted fabric layer 3 in the embodiment are significantly smaller than the openings 12 of the first warp-knitted fabric layer 2.

(36) FIG. 5 shows that the second warp-knitted fabric layer 3 has a lattice structure in which the yarns running in the production direction P and in the transverse direction Q result in a lower stretchability than in the first warp-knitted fabric layer 2. This is particularly due to a special knitting pattern that is provided for the second warp-knitted fabric layer 3. It is substantial for the low stretch along the production direction P that, according to FIG. 6, the second warp-knitted fabric layer 3 has a first yarn system 13 with a first knitting pattern in the form of a modified pillar pattern. According to FIG. 6, it is provided for the yarns of the first yarn system 13 that they form pillar stitches 14 in an alternating sequence in the production direction P and are guided without stitch formation. According to FIG. 6, two pillar stitches 14 are always formed along the production direction P and then two stitches are omitted, but the individual yarns are displaced around the respective needles along a stitch wale.

(37) To form the second warp-knitted fabric layer 3, a second yarn system 15 with a first partial yarn system 15a and a complementary second partial yarn system 15b is further provided. Since the two partial yarn systems 15a, 15b per se have a matching but complementary knitting pattern and together form the filet pattern, in the scope of the invention these are collectively referred to as the second yarn system 15, even if for each partial yarn system 15a, 15b in the knitting process a guide bar is provided. The two partial yarn systems 15a, 15b can be formed for example with two guide bars, each with a feed 1 full, 1 empty.

(38) According to FIG. 7, the yarns of the second yarn system 15 alternately form pillar stitches 14 and stitches of a cord pattern 16 along the production direction P. Specifically, two pillar stitches 14 alternate with two stitches of a cord pattern 16. A small stretch along the transverse direction Q is achieved through the stitches of a cord pattern 16.

(39) The sequence of two pillar stitches 14 and two stitches 16 of a cord pattern is only by way of example, it also being possible to provide a larger number with regard to the two stitch types. The cord pattern is also only shown by way of example. In addition, stitches selected from the group of tricot, satin, velvet, and atlas can also be considered.

(40) In order to achieve the lowest possible overall stretch, the second warp-knitted fabric layer 3 with the first yarn system 13 and the second yarn system 15 is made entirely of multifilament smooth yarn.

(41) The thickness of the spacer fabric 1 is typically between 2 mm and 20 mm, in particular between 3 mm and 15 mm.

(42) Whereas, according to FIG. 1, a rib structure of the compressed areas 7 is shown by way of example, FIGS. 8A and 8B show further possible embodiments, according to which a triangular pattern is shown there according to FIG. 8A, which is also referred to as a diamond pattern. It has also already been shown that different geometries or at least portions of different sizes can be formed by the compressed areas 7.

(43) According to FIG. 8B, a diamond pattern is provided.

(44) In contrast to FIG. 1, self-contained surfaces are formed on the compressed areas 7 by the decorative yarns 8 according to FIGS. 8A and 8B. The base areas each extending within the decorative yarns 8 can for example have an area between 3 cm5 and 100 cm5.

(45) According to FIG. 3 it is shown by way of example that the decorative cover layer 5 and the spacer fabric 1 are provided on an air distribution layer 11 that forms a pressure-elastic substructure. As an alternative, however, a dimensionally stable substrate can also be connected to the second warp-knitted fabric layer 3, in order to form for example a dashboard, a side panel, or another type of interior lining of a motor vehicle. Corresponding configurations are of course also conceivable in other areas in which a high-quality appearance or an appealing embodiment are desired.

(46) To illustrate the special advantages of the spacer fabric 1 according to the invention, a composite is only described by way of example in the embodiment that has compressed areas 7, the comparatively stretchable first warp-knitted fabric layer 2 adjoining the decorative cover layer 5, while the second warp-knitted fabric layer 3 having only a comparatively low stretchability can then stretch open the decorative cover layer 5 that is elastically supported by the spacer yarns.

(47) If, on the other hand comparatively large, uniformly curved surfaces are to be provided in a composite, the spacer fabric 1 according to the invention can be provided in exactly the reverse arrangement of the warp-knitted fabric layers 2, 3, the second warp-knitted fabric layer 3 then supporting the decorative cover layer 5 having less stretchability. With regard to possible embodiments, reference is made to the embodiments 3 of DE 10 2016 125 881, wherein a ventilation function advantageously can be provided by the embodiment according to the invention in the thickness direction, that is to say through the decorative cover layer 5, due to the inventive configuration of the spacer fabric 1, even in the case of corresponding embodiments of a composite. For this purpose, the decorative cover layer 5 can for example also be provided with openings in the manner of the perforation 6 described above.