Spacer knit and gasket assemblies

Abstract

The invention relates to a spacer knit, comprising two knit layers (1) and spacer yarns (2) connecting the knit layers (1), the knit layers (1) having loops following one another in the production direction (P), the loops having an average loop spacing of a, the knit layers (1) having openings (3) which extend in the production direction (P) by a length l, the length l being greater than 2*a, and the openings (3) of the two knit layers (1) being arranged substantially overlapping one another and forming opening pairs (4) accordingly. At least at some of the opening pairs (4), at least one pair (5) of crossing spacer yarn sections (6) is arranged respectively, which extend in the transverse direction (Q) of the openings (3), wherein at these opening pairs (4) the number of pairs (5) of crossing spacer yarn sections (6) is less than l / 2a.

Description

Technical Field

[0001] This invention relates to a spaced-knit fabric comprising two knitted layers and spacer yarns connecting the knitted layers. Each knitted layer has sequentially arranged loops in the production direction, with an average loop spacing of 'a'. Each knitted layer has openings extending in the production direction for a length 'l', where 'l' is greater than 2*a. The openings of the two knitted layers are substantially overlapping and correspondingly form opening pairs. The invention also relates to a padding assembly having the spaced-knit fabric, particularly for air-conditioned seats in motor vehicles. Background Technology

[0002] Spaced knit fabrics are characterized by their lightweight, breathable structure, and the elasticity in their thickness direction achieved through the spacer yarns extending between the two knit layers. For this purpose, monofilament yarns are typically used as spacer yarns, which possess relatively high resilience due to their structure.

[0003] Due to their elastic properties, spaced-knit fabrics can be used as soft, elastic layers that allow for air circulation in mattresses, upholstered furniture, clothing, or footwear. As technical textiles, spaced-knit fabrics are also used in the automotive industry, for example, in air-conditioned seats and seat covers, where they impart padding properties and excellent resilience, enabling a good contour fit.

[0004] This invention relates particularly to the last-mentioned technical textiles.

[0005] The distribution of production direction and transverse direction is common in knitted textiles, where the production direction is also referred to as the knitting direction or longitudinal direction. In spaced knitted fabrics, the individual yarns forming the fabric extend along the production direction, or knitting direction, and on this basis, present a knitting pattern that usually repeats. Accordingly, for example, the spacer yarns extend back and forth between two knitted layers and thus keep the two knitted layers apart.

[0006] According to the usual terminology, the two planar knitted layers have wales extending in the production direction and rows of loops extending in the transverse direction. The distance between the successive rows of loops in the production direction corresponds here to the average loop spacing 'a' mentioned earlier.

[0007] For example, DE 100 13 492 A1 discloses a vehicle seat in which a load-bearing spacer knitted fabric is provided in the seat area. This spacer knitted fabric is formed by two knitted layers and spacer yarns connecting the knitted layers. In particular, to create unsupported passageways and folded positions, the spacer yarns between the knitted layers can be partially omitted.

[0008] A shape-fitting spaced-knit fabric is known from DE 10 2005 029 755 A1, which, except for the opening (see... Figure 1 , 2 In addition, the arrangement of spacer yarns in different implementations is defined by a cycle length. Durable resilience is achieved through a specific number of spacer yarns per unit area and / or the special guidance of the spacer yarns in the spacer knit fabric.

[0009] This invention relates to a spaced-knit fabric with openings in both knit layers. It should be understood that textile products are, in principle, not sealed and that separate gaps and voids exist within the loops or between two directly adjacent loops. These gaps and voids are not referred to as openings within the scope of this invention. Rather, the openings extend at least twice the length of the loop spacing, thus forming macroscopic and clearly perceptible openings compared to the actual loop structure.

[0010] Furthermore, it is stipulated that the openings in the two knitted layers are substantially overlapping each other. Substantially overlapping is defined as the opening areas overlapping by at least 70%. Preferably, the openings completely overlap, except for fluctuations caused by statistical and production factors.

[0011] Several aspects are important when using spacer knit fabrics, especially in the form of cushioning components for air-conditioned seats.

[0012] Of course, the spacer fabric must have sufficient compressive stiffness to withstand the expected load, such as the weight of a user of an air-conditioned seat. It is also advantageous to achieve the lowest possible flow resistance both in the plane of the spacer fabric and when flowing out of the knit layer, when used as a fluid distribution layer.

[0013] In spaced knitted fabrics with sufficiently large openings, the flow resistance in the spacer yarn area, i.e., in the plane between knitted layers, plays a particularly crucial role.

[0014] Furthermore, for cost and efficiency reasons, it is highly advantageous if spaced knit fabrics can be manufactured as lightly as possible, as this reduces material usage and allows for the production of lighter products.

[0015] Finally, not only is sufficient compressive stiffness crucial, but the stress change curve during compression is equally important. What is generally considered particularly comfortable is that spaced knit fabrics feel soft under slight compression and then generate sufficient stress as evenly as possible as increasing compression.

[0016] The stress variation curve here depends on a range of different factors. A key factor is, for example, the orientation of the spacer yarns between the knitted layers, where the bending and folding characteristics of the individual spacer yarn segments extending between the two knitted layers can be observed. Furthermore, it should be noted that when subjected to force, the material can deform and do work to some extent in its width direction; therefore, depending on the structure and load, the spacer yarns may also tilt to one side as a whole. In this case, sufficient support is usually not provided.

[0017] In this context, it is equally clear that compressive hardness and, in particular, stress variation curves, as compression increases, are related to both the forces acting along the thickness direction and the derivation of these forces in the plane of the knitted layer.

[0018] It should also be noted that the knitting pattern produced during the knitting process determines how the spaced knitted fabric stands upright or is oriented after the knitting process.

[0019] A similar type of spaced-knit fabric is known from DE 10 2008 020 287 B3, characterized by very good functional properties. The spacer yarns are arranged such that, in a top view of the knitted layer, the spacer yarn segments connecting the knitted layer are arranged in an island-like pattern, with continuous, unspaced yarn channels between them. This spaced-knit fabric is characterized by both good mechanical properties and exceptionally low flow resistance.

[0020] In this context, it should be noted that in practice, the various connecting parts between knitted layers are also referred to as "spacer yarns". Within the scope of this invention, such connecting parts are called "spacer yarn segments", and the spacer yarns extending in the production direction thus form consecutive spacer yarn segments. Summary of the Invention

[0021] The objective of this invention is to provide a spaced-knit fabric that exhibits particularly good mechanical properties with minimal material usage and is therefore particularly suitable for use in padding assemblies. Furthermore, a padding assembly is also intended, particularly in the form of an air-conditioned seat for motor vehicles.

[0022] The technical solution of the present invention and the solution to the task are the spaced knitted fabric according to claim 1 and the padding assembly according to claim 15.

[0023] Therefore, starting from the same type of spaced knitted fabric, according to the present invention, at least a pair of intersecting spacer yarn segments extending in the transverse direction of the opening are provided in at least a portion of the opening pairs, preferably in all the opening pairs, and the number of intersecting spacer yarn segment pairs at these opening pairs is less than 1 / 2a.

[0024] The presence of at least one pair of intersecting spacer yarn segments provides a degree of lateral stability and force transfer in the open area. However, according to the invention, intersecting spacer yarn segments are not provided in every row of loops in the open area. If, for example, all spacer yarns extend obliquely, the spacer knit fabric will generally have only relatively low compressive stiffness, which is insufficient for the intended application.

[0025] In this context, according to a preferred design of the invention, the spacer yarns are knitted in a combination of type I padding and skew padding, wherein the ratio of the spacer yarn segments of the type I padding to the spacer yarn segments of the skew padding can be from 3:1 to 12:1, especially from 4:1 to 6:1. Therefore, most of the spacer yarn segments are formed in the form of type I padding, thus contributing to high compressive strength and uniform compression characteristics. The skew padding (especially the spacer yarn segments that also cross at the opening) provides stability and further actively modulates the compression characteristics.

[0026] Regarding the opening pair, in principle, it is not excluded that a pair of intersecting spacer yarn sections may be misaligned with each other, for example, by a row of loops. However, the preferred design is that a pair of intersecting spacer yarn sections are located in the same position with respect to the production direction, that is, in the same row of loops and forming an X shape.

[0027] According to a preferred design of the invention, a pair of intersecting spacer yarn sections extending in the transverse direction of the openings are provided at the opening pair. It is particularly advantageous if this pair of intersecting spacer yarn sections is located in the middle of the opening pair, or at least approximately in the middle, with respect to the production direction.

[0028] The length of the opening can be easily determined on the spaced knit fabric itself, and in this regard, it also depends to some extent on the specific knitting pattern of the knitted layer and may also depend on other influencing factors, such as yarn stress during the knitting process. The length of the opening can be between 3a and 12a, especially between 5a and 10a.

[0029] The opening is defined by a crossbeam formed by the warp threads of the loops, where adjacent warp threads can be connected to each other by spacer yarn sections. Diagonal padding is also present there, and X-shaped padding crossings can also be provided. However, since the warp threads extend close together, the angle formed by the crossing spacer yarn sections is significantly smaller.

[0030] In addition, the aforementioned crossovers at the crossbars can also contribute to the stability of the entire spaced knit fabric in a favorable manner.

[0031] The angle of the intersecting spacer yarn sections at the openings depends on both the total thickness of the spacer knit and the width of the openings. According to a preferred design of the invention, the intersecting spacer yarn sections at the openings extend relative to the knit layer at an angle between 25° and 60°, particularly between 35° and 55°.

[0032] According to a common design scheme within the scope of this invention, the spacer yarn segments that cross at the opening pairs extend only across the width of the respective opening pairs. However, it is not excluded in principle that they may cross at two or more openings in order to achieve, for example, the aforementioned preferred angle at a specific ratio of total thickness to opening width.

[0033] Within the scope of this invention, the total thickness of the spaced knitted fabric is preferably between 5 mm and 40 mm, but the invention is not limited to this range. A thickness between 8 mm and 15 mm is particularly preferred.

[0034] The spacer yarn is preferably formed by two guide bars, with a "one-through-one-gap" threading method (i.e., threading one yarn through every other needle) being particularly suitable on these guide bars. Monofilament yarn is particularly suitable here because its structure provides higher bending stiffness compared to multifilament yarn.

[0035] Within the scope of this invention, the openings of the two knitted layers substantially overlap and correspondingly form an opening pair. In this context, the same padding method can also be used for both knitted layers. Furthermore, the knitted layers can be entirely identical in terms of the yarn used, with multifilament yarn being particularly suitable for both knitted layers.

[0036] Within the scope of this invention, in order to form a suitable opening, the knitted layers are formed by at least two, preferably exactly two, combs.

[0037] It is possible that at least one of the knitted layers, preferably two knitted layers, has a first yarn system with terry padding and a second yarn system with partial weft yarns, through which the terry ribs of the first yarn system, which are segmentally adjacent, are connected to each other to form an opening.

[0038] The spaced-knit fabric according to the invention also exhibits particularly good elastic properties in terms of compression. In principle, spaced-knit fabrics are only compressible on a portion of their total thickness because from a certain point onward, the yarn material becomes similar to a coil spring entering a "fully compressed" state. At this point, a sharp increase in force occurs, and permanent damage may occur under excessive force load. However, in practice, such a load is usually not observed.

[0039] Given this background, it is known in common measurement methods that spaced knitted fabrics are compressed by 70% relative to their total thickness. That is, a 10mm thick sample will be compressed by 7mm, leaving a thickness of 3mm.

[0040] For dense and full-bodied spaced knit fabrics, a force increase may have already occurred, indicating that the material has begun to be fully compressed. However, within the scope of this invention, the aim is precisely to create a particularly lightweight spaced knit fabric with low material consumption, so there is generally no need to worry about the layering state under the corresponding compression.

[0041] For spaced knitted fabrics, it is known that stress, i.e., compressive stiffness, is given as a maximum value and / or a value under a specific deformation. However, precise studies of stress variation with deformation show that different materials have significantly different variation curves, and it is precisely this characteristic curve that is particularly important for the user's tactile perception.

[0042] Furthermore, it should be noted that spaced knit fabrics, when subjected to their first deformation immediately after production, can initially be significantly stiffer and may exhibit marked differences compared to their subsequent properties. In this context, the following description specifically addresses the properties of spaced knit fabrics after their first compression. During the first compression, depending on the material, high internal stress, adhesion, or similar phenomena still exist. After a certain number of deformations, these properties become almost unchanged, in which case the sustained elasticity of spaced knit fabrics is particularly prominent.

[0043] The average coil spacing 'a' and therefore the distance between successive rows of coils in the production direction can be between 1 mm and 3 mm.

[0044] According to a preferred design of the invention, the spaced-out knitted fabric is made of a single plastic material, particularly PET, thereby enabling the recycling of a single type of fabric in this case.

[0045] As previously mentioned, spacer knitted fabrics should be designed to be as lightweight and breathable as possible. Therefore, according to a preferred design according to the invention, the weight per unit area of ​​the spacer knitted fabric is between 250 g / m² and 450 g / m², particularly between 300 g / m² and 350 g / m². The given weight per unit area particularly relates to a preferred thickness between 8 mm and 12 mm, particularly a thickness of about 10 mm.

[0046] The present invention also relates to a padding assembly, particularly for an air-conditioned seat in a motor vehicle, comprising a surface layer and the aforementioned spacer knitted fabric, the spacer knitted fabric being disposed below the surface layer and configured as a fluid distribution layer. Attached Figure Description

[0047] The invention will now be described with reference to the accompanying drawings. The drawings are as follows:

[0048] Figure 1 A top view of the spaced-knit fabric is shown in photographic form;

[0049] Figure 2 Shown in photographic form according to Figure 1 A slanted view of the edge of the spaced knitted fabric;

[0050] Figure 3 The arrangement of comb pads is shown during the knitting process to form the spaced knit fabric;

[0051] Figure 4 A diagram showing the yarn movement of the spacer yarns in a spacer knitted fabric is provided.

[0052] Figure 5 The diagram shows the padding motion of the first and second yarn systems used to form the knitted layer;

[0053] Figure 6A shows the deformation-stress curve of the spaced knitted fabric according to the present invention; and

[0054] Figures 6B / 6C show the deformation-stress curves of spaced knitted fabrics in the prior art. Detailed Implementation

[0055] Figure 1 and 2 This illustration shows a spaced-knit fabric with two knitted layers 1, which are interconnected by spacer yarns 2. This structure combines... Figure 1 and Figure 2 This is particularly clear because the knitted layer 1 is designed in the same or substantially the same way in the illustrated embodiment and the knitted layer 1 is... Figure 1 They overlap in the top view.

[0056] As is commonly seen, the knitted layer 1 has loops sequentially arranged in the production direction P, with an average loop spacing of a, and the knitted layer has an opening 3 (see especially...). Figure 2 ).

[0057] As can also be seen from the explanation below, Figure 1 The spaced-knit fabric shown has a cycle length of twelve loops, meaning that the same structure appears again after every twelve loops.

[0058] Similarly from Figure 1 Observations show that the length l of opening 3 extending in the production direction P is greater than twice the average coil spacing a. For example, from... Figure 1 The length l can be estimated to be, for example, between 5a and 10a.

[0059] according to Figure 2 The openings 3 of the two knitted layers 1 are distinguishable from each other. However, according to... Figure 1 In the top view, the openings 3 of the two knitted layers 1 are set to basically overlap each other, so the corresponding pair of openings 4 can be seen in the top view.

[0060] It can be seen that at each pair of openings 4, there is a pair of intersecting interval yarn segments 6 that extend in the transverse direction Q of the opening 3. The interval yarn segments 6 that intersect at each pair of openings 4 extend at approximately a 45° angle relative to the knitted layer 1.

[0061] At each pair of openings 4, the intersecting spacer yarn segment 6 of this pair 5 is located in the middle of the corresponding pair of openings 4 with respect to the production direction P. The intersecting spacer yarn segment 6 at the pair of openings 4 particularly advantageously promotes the stability of the spacer knitted fabric in the transverse direction Q and the regulation of its compression characteristics.

[0062] exist Figure 1 and 2 As can be seen from the image, the opening 3 in the knitted layer 1 is defined by the crossbar 7 formed by the longitudinal loops of the loops. A preferred knitted pattern will be described in detail below.

[0063] Figure 3 This diagram shows the threading pattern of the six combs L1 to L6 in this case, so that they can form... Figure 1 and 2 The spaced knit fabric shown.

[0064] Two knitted layers 1 are formed by combs L1 and L2 on one side and by combs L5 and L6 on the other side. The spacer yarn 2 is formed by combs L3 and L4 through a "1-through-1-empty" yarn threading method, with the "1-through-1-empty" yarn threading methods of the two combs L3 and L4 staggered by one stitch length.

[0065] Figure 4 The diagram shows the yarn movement of the spacer yarn 2, with the pattern repeating for twelve loop rows. However, it should be considered that the spacer yarn 2 is incorporated into two knitted layers 1 and therefore connects to each of the two knitted layers in each loop row.

[0066] Depend on Figure 4 As can be seen, the spacer yarn 4 extends straight in the production direction P and thus a type I padding yarn is placed there. At every third loop (with respect to knitted layer 1), a diagonal padding yarn of spacer yarn 2, formed by two guide bars L3 and L4, is placed, thus creating a cross. These crosses alternately occur at the opening 3 on one hand and at two directly adjacent crossbars 7 on the other. This second type of cross is correspondingly located at… Figure 1 and 2 It is not visible in the middle, but it is still beneficial to improve the interlaced knit fabric.

[0067] Therefore, in the illustrated embodiment, the ratio of the spacer yarn section of the type I padding yarn to the spacer yarn section of the oblique padding yarn is 5:1.

[0068] The two knitted layers 1 have the same design. Figure 5 The knitting pattern of two knitted layers 1 is shown. A guide bar L2 and L5 are provided for each of the two knitted layers 1. When fully threaded, the guide bar uses the first yarn system to create looped longitudinal ridges through loop padding. An additional guide bar L1 and L6, threaded in a "1-through-1-open" manner, are assigned to a second yarn system. This second yarn system forms a portion of the weft yarn, which connects the segmentally adjacent looped longitudinal ridges formed by the first yarn system to form openings 3.

[0069] Figure 6A exemplarily shows a deformation-stress curve of a spaced-knit fabric according to the present invention, while Figures 6B and 6C correspondingly show curves of spaced-knit fabrics in the prior art.

[0070] The deformation-stress curves show the initial deformation, but this initial deformation is not important for the subsequent properties of the spaced knit fabric, because the spaced knit fabric only exhibits a partially significant increase in stress value during the initial deformation.

[0071] After multiple deformations, it exhibits stable characteristics. Corresponding change curves are also drawn in Figures 6A to 6C, and the following explanation will refer to these curves.

[0072] When determining the deformation-stress curve, deformation up to 70% of the total thickness was performed, followed by pressure unloading. As can be seen in Figure 6A, a remarkably uniform compression characteristic is observed. At the beginning of compression, the stress initially rises slowly and then increases uniformly, with the slope decreasing again before reaching the maximum compression of 70%.

[0073] Figure 6B shows the strain-stress curve of a prior art spaced-knit fabric. The corresponding spaced-knit fabric contains, among other yarns, a heat-fused yarn that is at least partially melted during manufacturing. The heat-fused yarn persistently promotes a degree of stability at specific locations within the spaced-knit fabric. It is precisely during the initial deformation that the spaced-knit fabric becomes very stiff, and this initial deformation can cause some of the connections formed by the heat-fused yarn to break.

[0074] After multiple deformations, a relatively steep increase in stress is observed after a soft initial region, giving the user the impression that the material is relatively hard. This is followed by a relatively flat region, and then a steeper increase is observed when the maximum deformation of 70% is reached, which may indicate the beginning of a layering state.

[0075] According to Figure 6C, another type of spaced knit fabric based on existing technology exhibits characteristics similar to those in Figure 6B. Stress rises relatively steeply over a relatively short stroke, followed by a plateau. Further compression then results in only a very limited increase in stress. Only before reaching 70% of maximum compression does the increasing slope reappear. The middle region of the curve may be uncomfortable for the user to perceive as a "dead zone."

Claims

1. A spaced-knit fabric comprising two knitted layers (1) and spacer yarns (2) connecting the knitted layers (1), the knitted layers (1) having sequentially arranged loops in a production direction (P) with an average loop spacing of a, the knitted layers (1) having openings (3) extending along the production direction (P) for a length l greater than 2a, and the openings (3) of the two knitted layers (1) being substantially overlapping each other and correspondingly forming opening pairs (4), characterized in that, In at least a portion of the opening pairs (4), at least one pair (5) of intersecting spacer yarn segments (6) extending in the transverse direction (Q) of the opening (3) are provided, wherein, in these opening pairs (4), the number of pairs (5) of intersecting spacer yarn segments (6) is less than l / 2a.

2. The spaced-knit fabric according to claim 1, characterized in that, At least one pair (5) of spacer yarn segments (6) are provided at each of the opening pairs (4) and extend in the transverse direction (Q) of the opening (3).

3. The spaced-knit fabric according to claim 1 or 2, characterized in that, At the corresponding opening pair (4), there is a pair (5) of intersecting spacer yarn segments (6) that extend in the transverse direction (Q) of the opening (3).

4. The spaced-knit fabric according to claim 3, characterized in that, The pair (5) of the intersecting interval yarn section (6) is located in the middle of the opening pair (4) with respect to the production direction (p).

5. The spaced-knit fabric according to any one of claims 1 to 4, characterized in that, The length l of the opening (3) is between 3a and 12a, especially between 5a and 10a.

6. The spaced-knit fabric according to any one of claims 1 to 5, characterized in that, The opening (3) is defined by a crossbar (7), which is formed by a row of coils, and a spacer yarn section is provided at the crossbar (7) to connect adjacent rows of coils.

7. The spaced-knit fabric according to any one of claims 1 to 6, characterized in that, The spacer yarn (2) is knitted in a combination of type I spacer yarn and oblique spacer yarn, wherein the ratio of the spacer yarn section of type I spacer yarn to the spacer yarn section of oblique spacer yarn is 3:1 to 12:1, especially 4:1 to 6:

1.

8. The spaced-knit fabric according to any one of claims 1 to 7, characterized in that, The spacer yarn (2) is formed by two combs (L3, L4) in a one-through-one-open manner.

9. The spaced-knit fabric according to any one of claims 1 to 8, characterized in that, The two knitted layers (1) have the same padding method.

10. The spaced-knit fabric according to any one of claims 1 to 9, characterized in that, The knitted layer (1) is formed by two combs (L1, L2; L5, L6).

11. The spaced-knit fabric according to any one of claims 1 to 10, characterized in that, At least one of the knitted layers (1) has a first yarn system with terry pad yarn and a second yarn system with partial weft yarn, wherein the terry ribs formed by the first yarn system are connected to each other in sections by the partial weft yarn to form an opening (3).

12. The spaced-knit fabric according to any one of claims 1 to 11, characterized in that, The total thickness is between 5mm and 40mm.

13. The spaced-knit fabric according to any one of claims 1 to 12, characterized in that, The average coil spacing 'a' is between 1 mm and 3 mm.

14. The spaced-knit fabric according to any one of claims 1 to 13, characterized in that, The spacer yarn segments (6) that cross at the opening pair (4) extend relative to the knitted layer (1) at an angle between 25° and 65°, especially between 35° and 55°.

15. A padding assembly, particularly for air-conditioned seats in motor vehicles, the padding assembly comprising a surface layer and a spaced-out knitted fabric disposed beneath the surface layer, according to any one of claims 1 to 14, the spaced-out knitted fabric serving as a fluid distribution layer.

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