AU2021440929A1

AU2021440929A1 - Warp knitted spacer mesh fabric with high air permeability, elasticity and support

Info

Publication number: AU2021440929A1
Application number: AU2021440929A
Authority: AU
Inventors: Chen Yu
Original assignee: Lear Corp
Current assignee: Lear Corp
Priority date: 2021-04-11
Filing date: 2021-09-10
Publication date: 2023-07-20
Also published as: EP4248009A1; DE112021005682T5; GB2621279A; JP2024512176A; KR20230128087A; AU2021440929A9; CN116761912A; GB202317061D0; WO2022217825A1

Abstract

A spacer fabric (10) is comprising a first knit layer (12), a second knit layer (14) and a third layer (16) comprising monofilament spacer yarns extending between and connecting the first and second knit layers (12, 14), with the first knit layer (12) having a mesh structure.

Description

[Title established by the ISA under Rule 37.2] WARP KNITTED SPACER MESH FABRIC WITH HIGH AIR PERMEABILITY, ELASTICITY AND SUPPORT

CROSS REFERENCE OF RELATED APPLICATION

The present application claims a priority of the PCT Application PCT/CN2021/086319 filed on April 11, 2021, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

One or more embodiments relate to a warp knitted spacer fabric with one or more warp knit mesh layers, a cushion layer made of the spacer fabric, a composite material made of the spacer fabric, a trim cover made of the spacer fabric, and a method of making the same. At least one or more certain other embodiments relate to a warp knitted 3D spacer mesh fabric, and in particular, to a manufacturing process of warp knitted 3D fabric with high permeability and high resilience.

BACKGROUND

With the continuous improvement of peoples’ living standards, peoples’ requirements for comfort (softness, elasticity /ventilation) and environmental protection of automobile seat cushion are also increasing. Under the traditional car seat cushion a layer foam, such as polyurethane foam, is typically used. In some instances, it would be desirable to try to inhibit or minimize the use of polyurethane foam.

Spacer fabrics are versatile and as such are usable in many different applications. A spacer fabric is flexible and thus easily bendable. A spacer fabric can also be air permeable. Another feature found in most spacer fabrics is resilience.

Due to the various advantageous properties of a spacer fabric, the spacer fabric can be used in a variety of applications including, but not limited to; furniture, like seats, mattresses and upholstered articles; vehicular components, like climate-and non-climate automobile seats, trim and seat covers, and trim panels, such as door panels, dashboards, consoles, and headliners; and wearable articles like, athletic shoes and clothing.

Warp knitted 3D mesh fabric has been gradually applied to replace some or all of certain uses of polyurethane foam because of its soft elasticity and environmentally friendly material, However, the warp knitted 3D mesh fabric which has been applied in this field has been found to have limited, and possibly insufficient, stability of the middle connecting support monofilament. In some instances, when the middle connecting support monofilament has been compressed with the upper and lower fabrics of the 3D fabric, the middle connecting support monofilament has been found to relatively easily fall down laterally or compress under pressure, resulting in less than ideal elasticity, and comfort.

Moreover, spacer fabrics can be useable as a composite material or trim material. Suitable composite materials comprise a spacer fabric sandwiched between a cover layer, which can be decorative, such as leather, vinyl or fabric, and a base, which can be a rigid or flexible base layer.

In at least certain embodiments, the present disclosure aims to overcome perceived deficiency of the prior art, and provide warp knitted 3D fabric having relatively high air permeability and elastic recovery.

SUMMARY

In one embodiment a spacer fabric is provided comprising a first knit layer, a second knit layer and a third layer comprising monofilament spacer yarns extending between and connecting the first and second knit layers to form an integral three-dimensional network structure. The spacer fabric, in at least one embodiment, has relatively high permeability.

Generally speaking, on the premise of ensuring the basic functionality of the fabric, the greater the voids (size of the hole) in the fabric (both upper and lower) , the better the air volume. The comfort and support of spacer fabric is related to its elasticity and recovery. This is also related to the stiffness of the connecting monofilament and the ability of the upper and lower fabric to hold the connecting monofilament. In at least one embodiment, the first layer is a mesh layer forming the upper fabric and the second layer is a plain cloth, or generally solid layer, forming the lower fabric with the first and second layers having unique structures. These structures not only guarantee good grip and connection of monofilament but also has good ventilation.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic perspective view of a spacer fabric in accordance with an embodiment of the present disclosure;

Figure 2 is a photograph of an embodiment of the spacer fabric of Figure1;

Figure 3 is a blown-up exploded view of an embodiment of spacer fabric schematically showing details of embodiments of the layers of the spacer fabric;

Figure 4 is a photograph at 10X magnification of an embodiment of the first layer mesh fabric;

Figure 5 is a schematic digital picture of an embodiment of the first layer mesh fabric;

Figures 6A and B are illustrations of the first layer yarn movements of an embodiment of the first layer mesh fabric;

Figure 7 is an illustration of the first layer yarn movements of an embodiment of the first layer fabric;

Figure 8 is an illustration of the first layer yarn movements of an embodiment of the first layer mesh fabric;

Figure 9 is a photograph at 10X magnification of an embodiment of the second layer plain fabric;

Figure 10 is a single yarn movement chart illustrating the movement of the yarn in the second layer of the fabric;

Figure 11 is an illustration of the second layer yarn movements of an embodiment of the second layer of the fabric;

Figure 12 is warp knitting diagram of the 3D spacer mesh fabric;

Figure 13 is an illustration of the first layer yarn movements of the first layer mesh fabric in accordance with another embodiment;

Figure 14 is an illustration of the first layer yarn movements of the first layer fabric in accordance with another embodiment;

Figure 15 is an illustration of the first layer yarn movements of the first layer mesh fabric in accordance with another embodiment; and

Figure 16 is a photograph at 10X magnification of the first layer mesh fabric in accordance with another embodiment.

DETAILED DESCRIPTION

As required, detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure.

With reference to Figures 1 and 2, a representative a spacer fabric 10 of the present disclosure is illustrated. The spacer fabric 10 could be used in a variety of applications. In certain embodiments, the spacer fabric 10 could be used as a seat cushion layer, either with or without a corresponding foam layer, such as a layer of polyurethane foam. The spacer fabric 10 could be used as a cushion, or cushion component in any cushion application, such as a seat bottom a seatback, and/or a trim panel.

In other embodiments, the spacer fabric 10 could be used as a trim layer component, wherein the spacer fabric 10 is secured below a trim layer. In such an embodiment, any suitable trim layer could be used, such as, but not limited to, leather, synthetic leather, plastics, such as vinyl, and fabric layers. The trim layer, or decorative layer, can be secured to the spacer fabric 10 by any suitable technique, such as by stitching or adhesive, for instance.

In other embodiments, the spacer fabric 10 can be used as a composite material requiring some level or elasticity and/or breathability. It should readily be understood that the composites made with a spacer fabric 10 of the present disclosure could be other automotive or non-automotive composites.

As illustrated schematically in Figures 1-3, the spacer fabric 10 has a mesh first knit layer 12, a generally solid or closed, (i.e., plain) second knit layer 14 and spacer yarns 16 extending between and connecting the first and second knit layers 12 and 14.

In certain other embodiments, spacer fabric 10 comprises a warp knitted 3D mesh fabric having a warp knitted mesh fabric upper layer 12, a warp knitted fabric (without mesh) lower layer 14, and monofilaments 16 knitted into the upper and lower layers 12 and 14 to form an integral three-dimensional network structure 10.

In certain other embodiments, and as will be described in more detail below, the spacer fabric 10 of the present disclosure has relatively high air permeability, elasticity and support compared to other fabrics. In this regard, the spacer fabric 10 of the present disclosure, is particularly suitable for use in the lower cushion material of an automobile seat. In at least certain embodiments, the mesh forming the upper fabric 12 and the plain cloth forming the lower fabric 14 have unique structures, which are representatively shown in the Figures.

In certain embodiments, the two knit layers 12 and 14 have stitch wales that run in the production direction and stitch courses that run in the transverse direction. The spacer yarns 16 that extend between and connect the first and second knit layers 12 and 14 can be any suitable monofilament yarn.

In certain other embodiments, the upper layer 12 and bottom layer 14 are made of common multi strand polyester filament. In at least one embodiment, the upper layer 12 and bottom layer 14 are made of common multi strand polyester filament having a size 83 dtex/36F, and the middle connection monofilament 16 having a size 33 -44 dtex/1F. It should be understood that other sizes and or types of yarn can be used and still be consistent with the present disclosure.

In at least certain other embodiments, the interlayered yarn 16 should have good stiffness and resilience. In certain other embodiments, the size and thickness of monofilament can be selected depending upon the desired compression strength and spring back deformation characteristics desired to be achieved. In at least still certain other embodiments, the size of monofilament yarns 16 is 33-44dtex. It should be understood that other sizes and or types of monofilaments can be used and still be consistent with the present disclosure.

As best seen in Figures 4-5, the first layer 12 has openings 8. In at least certain embodiments, the openings in the upper layer 12 are shown to be generally oval in shape, however the openings 8 can be any suitable shape such as elongated, circular, square and/or rectangular, to name a few. The size of the openings 8 on the upper layer 12 can be adapted to any suitable size as required. Usually, the larger the opening 8, the better the air volume, however, the support will lessen with the increase of size of the opening 8. In at least one embodiment, the upper layer 12 have a higher air permeability than the lower layer 14.

An image of an exemplary embodiment of the first knit layer 12 is shown in Figure 5. As can be seen in the Figures, the first knit layer 12 has an open mesh structure. As representatively shown in the illustrated embodiments, the open mesh structure of the first knit layer 12 has a plurality of strips 6 of fabric broken up with a plurality of spaced openings 8.

In at least the illustrated embodiments, the openings 8 are generally oval and extend in offset and staggered rows. In at least one embodiment, the openings 8 are spaced in staggered rows. In at least one embodiment, the openings 8 are spaced 0.5 to 10 mm, on center, in the width direction and are spaced 0.5 to 10 mm, on center, in the length direction.

As schematically shown in one embodiment in Figs. 3 and 12, the spacer fabric 10 can be produced by a warp knitted double needle bar machine. As schematically and representatively illustrated, five pattern bars 11, 13, 15, 17 and 19 can be used to direct the yarn 21, 23, 25, 27 and 29 to the needles 31 and 33. The pattern bars 17 and 19 can be used to direct yarn 21 and 23 to the needles 31 for knitting the first layer of mesh fabric 12. The pattern bars 13 and 15 are used to direct the yarn 25 and 27 to the needles 31 and 33 for knitting the support monofilament 16. The pattern bar 11 is used to direct the yarn 29 to the needle 33 for knitting the underlay fabric 14.

The first layer 12 has an open mesh structure, as schematically shown in Figs. 4 and 12. Figures 6A and 6B show an embodiments of a suitable single yarn pad yarn movement chart of two pattern bars. The motion diagram of padding yarn is a coil formed by a needle from bottom to top. The horizontal dot column is used to represent the needles arranged on the needle bed in turn. The top of point 22 represents the front of the needle hook and the bottom of point 22 represents the back of the needle. The yarn 21 swings through the pattern bar 19 to complete the needle 31 hook pad yarn and the needle 31 back traverse. The motion law is shown in the motion curve of yarn 21 and 23 in figures 6A and 6B. In the same way, yarn 23 completes the above padding motion through pattern bar 17.

As representatively shown in Figures 6A and 6B, for the first layer 12 of fabric pad yarn movement diagram, the motion diagram of pad yarn shows the coil formed by needle in turn with dot (as shown in 22) lines from bottom to top. Points in the transverse direction are used to represent the needles (N1/N2/N3/N4/N5/N6/N7/N8……) arranged in turn, with the upper part of the point 22 indicating the front of the needle hook, and the lower part of the point 22 indicates the back of the needle. The continuous line segment is used to represent the movement of the yarn guide needle of the pattern bar in front of the needle and at the back of the needle. Generally, the numbering (digitization) of padding is 0, 1, 2, 3, 4, 5, 6, 7, 8... from right to left in order between needles and is used to represent the motion track of the pattern bar. C1 --C12......denotes the row C formed by looping the yarn from the bottom to the top. The arrow 47, etc. indicates the movement direction of the yarn 23 guiding through the pattern bar 17. The motion law of all the yarns on the pattern bar 17 is the same, and yarn 23 is at least the illustrated embodiment, however it should be understood that other motion laws could be employed. In the illustrated embodiment, the stitch formation of one of the pattern bars 17 is recorded as: 1-0/1-2/1-0/1-2/7-8/7-6/7-8/7-6//, in Figure 6, where “1-0 ” corresponds to 39 in the C1 course, “1-2 ” corresponds to 40 in the C2 course where “1-0 ” corresponds to 41 in the C3 course, “1-2 ” corresponds to 42 in the C4 course, “7-8 ” corresponds to 43 in the C5 course, “7-6 ” corresponds to 44 in the C6 course where “7-8 ” corresponds to 45 in the C7 course, “7-6 ” corresponds to 46 in the C8 course. The movement of the yarn cushion of pattern bar 19 is completely symmetrical with that of pattern bar 17. The pad yarn of pattern bar 19 is recorded in the illustrated embodiment as: 7-8/7-6/7-8/7-6/1-0/1-2/1-0/1-2//. The numbers represent the mesh stitch formations of one of the bars with both bars working together to create the mesh pattern. In addition, the principal explanation of all the following motion diagrams of padding is the same as that in this paragraph, with the only difference being the motion law of padding.

The first layer 12 has an open mesh structure, as shown in the embodiment illustrated in Figures 4, 7 and 8. In the embodiment illustrated in Fig. 7, the motion diagram of a single pattern bar shows that the threading rule of the yarn on the same pattern bar is a series of three continuous threads 51 separated by one void 53 of this cycle, and there is no connecting yarn between the two lengthways of the hollow part to form a mesh opening 8. In this embodiment, the law of the yarn is a threading pattern of three in and one out repeating across the machine. It should be understood that some may fall outside the above described and illustrated ranges and still be consistent with the present disclosure.

As shown in embodiments illustrated in the figures, the yarn 21 and 23 on the two pattern bars are symmetrically directed into the needle hook according to the movement rule of Figures 6A, 6B and 8. In at least one embodiment, the coils in the adjacent longitudinal lines are not connected, and they are inclined in the opposite direction to form a mesh opening 8 as shown in Figures 4 and 8, and the coils in the adjacent longitudinal lines are connected and close to each other to form strips of fabric 6. The open mesh structure of the first knit layer 12 has a plurality of openings 8 and strips of fabric 6. In at least one embodiment, the openings 8 in length have four courses, as shown in the example of Figure. 8, but it should be understood that the openings 8 can have any suitable size which can be increased or decreased corresponding number of coils according to the need, especially depending on the desired level of air permeability. In at least one embodiment, the strips of fabric 6 have four wales, as shown in the examples Figures 4 and 8, in width and four courses, as shown in the example of Figure 6, in length between the mesh holes, but can have any suitable size. While most if not all of the openings fall within the above ranges, it should be understood that some may fall outside the above ranges and still be consistent with the present disclosure.

A second embodiment of the first layer 12 having an open mesh structure is schematically shown in Figures 13-16. In the embodiment shown in Figure14, the motion diagram of the single pattern bar shows that the threading rule of the yarn on the same pattern bar is a series of three threading 26 separated by one void 61 of this cycle. As shown in this embodiment, there is no connecting yarn between the two lengthways of the hollow part to form a mesh opening 63. It should be understood that some may fall outside the above ranges and still be consistent with the present disclosure.

In the embodiment of the first layer 12 having an open mesh structure shown in Figures 13-16, the yarn 30 and 71 on the two pattern bars are symmetrically directed into the needle hook according to the movement rule of Figures 13 and 15. In at least one embodiment, the coils in the adjacent longitudinal lines are not connected, and they are inclined in the opposite direction to form a mesh opening 63 as shown in the Figures 15 and 16, and the coils in the adjacent longitudinal lines are connected and close to each other to form the strips of fabric 28. The open mesh structure of the first knit layer 12 has a plurality of openings 63 and strips of fabric 28. In at least this embodiment, the openings 63 have six courses in length, as shown in the example of Figure 15, but the openings 29 can have any suitable size which can be increased or decreased corresponding number of coils according to the need especially depending on the desired level of air permeability. In at least this embodiment, the strips of fabric 28 has four wales, as shown in the examples in Figures 15 and16, and six courses in width, as shown in the example of Figure 13 at 67. It should be understood however that the length between the mesh holes can have any suitable size. While most if not all of the openings fall within the above ranges, it should be understood that some may fall outside the above ranges and still be consistent with the present disclosure1.

An embodiment of the second layer structure 14 is as shown in the Figures 9-11. As shown in the example in Figure 12, single pattern bar is directing the full threaded bar to the knitting needle, so that each needle is covered with yarn, so that each needle knits yarn.

In the embodiment of the second layer structure 14 as shown in the Figures 9-11, and in the example as shown in the Figure 12, the pattern bar 11 drives the yarn 29 to direct the yarn into the hook 33 according to the motion law of 69 in Figure 10. An embodiment of the knitted fabric is shown in Figure 9.

In the second layer structure 14 as shown in the embodiments of Figures 9-11, the fabric structure of this layer is a warp plain, generally solid (i.e., no mesh generation) , fabric that traverses across two or more needles, and the single pattern bar is directing yarns to the needles according to the embodiment illustrated in Figures 10 and 11. The length of the extension line 38 is related to the transverse density of the fabric, and also to the number of needles that are traversed when the yarn is fed, with the more needles through or the smaller the transverse density of the fabric, the longer the corresponding extension line 38.

It should be noted that prior art methods usually use two pattern bars to direct the yarn, which makes the structure very rigid and with low elasticity. In at least one embodiment of making the second layer structure 14 of the present disclosure, a single pattern bar is used to make the structure soft and elastic. The length of extension line 38 as shown in the Figures 9 and 10 helps to determine the elasticity of the fabric.

In the middle connecting monofilament 16 as shown in Figures 1-3 and 12, in at least the embodiment illustrated in Figure 12, the two pattern bars 13 and 15 drives the yarns 25 and 27 to direct the yarns into the needles hook 31 and 33.

In the middle connecting monofilament 16 structure as shown in Figures 1-3, with the first knit layer 12 and second knit layer 14, in at least the illustrated embodiments, two pattern bars are symmetrical padding yarn, and participate in the knitting of the first layer 12 and the second layer 14 respectively. Thus, the monofilament 16 can combine with two knit layers 12 and 14 tightly to form the 3D network structure 10. The first knit layer 12 and second knit layers 14 can hold and connect the monofilament 16 firmly through the structure of 6 and 14 in Figures 4 and 9, so that the connecting monofilament 16 is firmly held and fixed. In at least one embodiment, the thickness of the 3D spacer mesh fabric can be determined by the length of the connecting monofilament 16. In at least one embodiment, the fabric thickness is 9-10 mm, but it should be understood that this is just one example, and the thickness can be adjusted according to the needs with the present disclosure.

In at least certain other embodiments, in order to achieve a spacer fabric 10 that is soft, comfortable, elastic and has good air permeability, a layer, and in certain embodiments, the upper layer 12, is provided with a fabric layer interval arranged with mesh openings 8 and plain patterns 6, enabling the mesh to allow the fabric have excellent air permeability. In certain embodiments, the mesh size can be adjusted according to desired ventilation requirement. The plain weave portions help to makes the middle connecting monofilament 16 and upper fabric 12 more stable and firm. Thus, the stability and straightness of the intermediate connecting monofilament 16 can be relatively good, and inhibit the monofilament from becoming tilted and/or bunched. Due to the action of mesh, the monofilament 16 can be relatively evenly distributed, and the force can be distributed over a relatively larger surface area and help to avoid local collapse. In at least certain other embodiments, the monofilament has good stability due to plain grain consolidation, and it is not easy to fall down laterally, and the elastic recovery of the fabric can be improved relative to other fabrics.

In at least one embodiment, the spacer fabric 10 has a thickness of 8-12mm, in another embodiment of 8.5-11 mm, and in yet another embodiment of 10 mm.

The elasticity and support of the 3D spacer fabric 10 is related to the stiffness of monofilament 16 and the structure and vertical and horizontal density of the fabric. The upper and lower fabric structures 12 and 14 described above can hold the connecting monofilament 16 well, thereby helping to inhibit the filament 16 from side lodging under external pressure, which helps to inhibit the elasticity and support of the fabric from become poor. In addition, if the stiffness of the intermediate connecting monofilament 16 is too large or too small, the elasticity and comfort of the fabric will be poor. With the increase of the vertical and horizontal density of the fabric, the support will be stronger. In at least one embodiment, the elasticity and support of the fabric is measured by compression stress values of 5 ± 2 KPa, but it is not limited to this value. In at least one embodiment, the spacer fabric 10 of the present disclosure has a compression stress value of about 4.2 KPa. Compression stress value can be measured by Test Method: DIN EN ISO 3386-1, Vorkraft 0, 1 Pa; 80x80mm/100mm/min.

The high air permeability of the 3D spacer fabric 10 is related to the gap between the upper and lower fabrics 12 and 14. Generally speaking, the larger the gap, the better the air permeability, but the size of the fabric gap can restrict the elasticity and support. In at least one embodiment, the air permeability of the spacer fabric 10 is generally ≥3500 mm/s, but it is not limited to this value. In at least one embodiment, the spacer fabric 10 of the present disclosure has an air permeability of about 5000 mm/s. Air permeability can be measured by Test Method: DIN EN ISO 9237 2 mbar, Test sample: 20 cm ².

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosure. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the disclosure.

Claims

A spacer fabric comprising:

a first knit layer;

a second knit layer; and

spacer yarns extending between and connecting the first and second knit layers,

the first knit layer having a mesh structure comprising a plurality of spaced openings separated by plain fabric sections,

the second knit layer having a plain structure;

wherein the spacer fabric has a compression stress value of 5 ± 2 KPa and an air permeability of ≥3500 mm/s.
The spacer fabric of claim 1, wherein the first layer has openings spaced apart in Offset rows.
The spacer fabric of claim 2, wherein in the openings are generally circular, elongated, oval, square and/or rectangular in shape.
The spacer fabric of claim 3, wherein the openings are spaced 0.5 to 10 mm, on center, in the width direction and are spaced 0.5 to 10 mm, on center in the length direction.
The spacer fabric of claim 1 wherein the first and second knit layers together with the spacer yarns form an integral three-dimensional network structure.
The spacer fabric of claim 1, wherein the spacer fabric comprises a cushion layer in a vehicle seat trim cover.
The spacer fabric of claim 1, wherein the upper layer has a higher air permeability than the lower layer.
The spacer fabric of claim 1, wherein the first layer comprises a series of three threads separated by a thread sized void.
The spacer fabric of claim 1, wherein each of the opening of the first layer is separated by three yarn threads.
The spacer fabric of claim 1, wherein each of the plain fabric sections is made of three yarn threads.
The spacer fabric of claim 1, wherein each of the plurality of openings comprises one wale in width and four courses in length.
The spacer fabric of claim 11, wherein each of the fabric sections comprises four wales in width and four courses in length.
The spacer fabric of claim 1, wherein each of the plurality of openings comprises one wale in width and six courses in length.
The spacer fabric of claim 13, wherein each of the fabric sections comprises four wales in width and six courses in length.
A spacer fabric comprising:

a first knit layer;

a second knit layer; and

spacer yarns extending between and connecting the first and second knit layers,

the first knit layer having a mesh structure comprising a plurality of spaced openings separated by fabric sections,

wherein each of the plurality of openings comprises one wale in width and at least four courses in length.
The spacer fabric of claim 15, wherein each of the plurality of openings Comprises six courses in length.
The spacer fabric of claim 11, wherein each of the fabric sections comprises four wales in width and at least four courses in length.
The spacer fabric of claim 17, wherein each of the fabric sections comprises six courses in length.
The spacer fabric of claim 15, wherein the spacer fabric has a compression stress value of 5 ± 2 KPa and an air permeability of ≥3500 mm/s.
The spacer fabric of claim 15, wherein the spacer fabric has a thickness of 8-12 mm.