Method for producing a decorative composite having at least one local weakening and a weakened spacer fabric

Abstract

Method for producing a weakened decorative composite from at least one decorative material (25) and a spacer fabric (11), in particular for producing coverings of airbags in motor vehicles, which spacer fabrics (11) have an upper cover layer (12) and a lower cover layer (13) and a layer (15) having spacer threads (14) is located between the cover layers (12, 13), wherein the weakenings in the spacer fabric (11) are blind holes (16) which are introduced into the lower cover layer (13) of the spacer fabric (11), wherein the blind holes (16) substantially pass through the lower cover layer (13) and the layer (15) having the spacer threads (14) and the upper cover layer (12) is substantially not weakened.

Claims

1. Method for producing a weakened decorative composite from at least one decorative material and a spacer fabric for producing coverings of airbags in motor vehicles, which spacer fabric has an upper cover layer and a lower cover layer, and a layer having spacer threads is located between the cover layers, characterised in that the weakenings in the spacer fabric are blind holes which are introduced into the lower cover layer of the spacer fabric, wherein the blind holes substantially pass through the lower cover layer and the layer having the spacer threads, wherein the upper cover layer is substantially not weakened, wherein the lower cover layer is knitted, wherein the spacer fabric is a three-dimensionally structured technical textile that has a defined distance between the upper cover layer and the lower cover layer, wherein the upper cover layer and the lower cover layer are bound together by a binding element, wherein the spacer threads are the binding element between the upper cover layer and the lower cover layer, and wherein the blind holes are introduced by a laser.

2. Method according to claim 1, characterised in that the blind holes are slot-shaped and the slot length of the blind holes is between 0.2 mm and 2.0 mm.

3. Method according to claim 1, characterised in that bars are between the blind holes and two weakening lines run in parallel to each other and the blind holes or bars are arranged in gaps on the two weakening lines, wherein the distance between the two weakening lines is between 0.1 mm and 2.0 mm.

4. Method according to claim 1, characterised in that the at least one decorative material is then applied to the upper cover layer of the weakened spacer fabric.

5. Method according to claim 1, characterised in that the at least one decorative material is also weakened.

6. Method for producing a weakened spacer fabric for producing coverings of airbags in motor vehicles, which spacer fabric has an upper cover layer and a lower cover layer, and a layer having spacer threads is located between the cover layers, characterised in that the weakenings in the spacer fabric are blind holes which are introduced into the lower cover layer of the spacer fabric, wherein the blind holes substantially pass through the lower cover layer and the layer having the spacer threads, wherein the upper cover layer is substantially not weakened, wherein the lower cover layer is knitted, wherein the spacer fabric is a three-dimensionally structured technical textile that has a defined distance between the upper cover layer and the lower cover layer, wherein the upper cover layer and the lower cover layer are bound together by a binding element, wherein the spacer threads are the binding element between the upper cover layer and the lower cover layer, and wherein the blind holes are introduced by a laser.

7. Method according to claim 6, characterised in that the blind holes are slot-shaped and the slot length of the blind holes is between 0.2 mm and 2.0 mm.

8. Method according to claim 6, characterised in that the blind holes are slot-shaped and the slot length of the blind holes is between 0.3 mm and 1.0 mm.

9. Method according to claim 6, characterised in that the blind holes are slot-shaped and the slot length of the blind holes is between 0.5 mm and 0.8 mm.

10. Method according to claim 6, characterised in that the blind holes are arranged on at least one weakening line.

11. Method according to claim 6, characterised in that bars are between the blind holes, the length of said bars being between 0.2 mm and 1.0 mm.

12. Method according to claim 6, characterised in that bars are between the blind holes, the length of said bars being between 0.3 mm and 0.8 mm.

13. Method according to claim 6, characterised in that bars are between the blind holes, the length of said bars being between 0.4 mm and 0.6 mm.

14. Method according to claim 6, characterised in that bars are between the blind holes and two weakening lines run in parallel to each other and the blind holes or bars are arranged in gaps on the two weakening lines.

15. Method according to claim 6, characterised in that bars are between the blind holes and two weakening lines run in parallel to each other and the blind holes or bars are arranged in gaps on the two weakening lines, wherein the distance between the two weakening lines is between 0.1 mm and 2.0 mm.

16. Method according to claim 6, characterised in that bars are between the blind holes and two weakening lines run in parallel to each other and the blind holes or bars are arranged in gaps on the two weakening lines, wherein the distance between the two weakening lines is between 0.3 mm and 1.0 mm.

17. Method according to claim 6, characterised in that bars are between the blind holes and two weakening lines run in parallel to each other and the blind holes or bars are arranged in gaps on the two weakening lines, wherein the distance between the two weakening lines is between 0.6 mm and 0.8 mm.

18. Method according to claim 6, characterised in that the blind holes are introduced into the lower cover layer of a spacer fabric laminated onto a decorative material.

Description

(1) The invention as well as further advantageous embodiments and developments of the same are described and explained in more detail below by means of the examples depicted in the drawings. The features to be gleaned from the description and the drawings can be applied individually or together in any combination according to the invention. Here are shown:

(2) FIG. 1 a cross-section through a spacer fabric having a blind hole,

(3) FIG. 2 a decorative composite made from a decorative material and the weakened spacer fabric,

(4) FIG. 3 a schematic depiction of a preferred arrangement of the blind holes on two weakening lines,

(5) FIG. 4 a microscopic image of the rear side of the spacer fabric with a weakened lower cover layer and

(6) FIG. 5 a microscopic image of the upper side of the spacer fabric with unweakened upper cover layer, through which the weakening located underneath the upper cover layer is recognisable.

(7) In FIG. 1, a spacer fabric 11 having an upper cover layer 12, a lower cover layer 13 and a layer 15 lying between the upper 12 and the lower 13 cover layer having spacer threads 14 is depicted schematically in cross-section. Spacer fabrics are three-dimensionally structured technical textiles which have a defined distance between the two knitted cover layers 12, 13.

(8) The cover layers 12, 13 consist of polyester multifilaments which provide the spacer fabric with specific soft surface haptics.

(9) The spacer threads (end threads) 14 are the binding element between the two cover layers 12, 13 and are responsible for the thickness and compressive elasticity of the 3D textile. The spacer threads 14 consist of polyester monofilaments and provide the spacer fabric 11 with the required strength.

(10) A blind hole 16 is introduced into the spacer fabric 11, said blind hole extending on the lower side 20 of the spacer fabric 11 through the lower cover layer 13 and the layer 15 having the spacer threads 14. The upper cover layer 12 is substantially undamaged.

(11) FIG. 2 shows the weakened spacer fabric 11 from FIG. 1 which is adhered to the decorative material 25 with its undamaged cover layer 12 by means of an adhesive layer 24. Generally, the decorative material 25 is also weakened (not depicted).

(12) A possible arrangement of the blind holes 16 is depicted in FIG. 3. The blind holes 16 are longitudinal (slot-shaped) in the top view. Their slot length 33 is, in this preferred embodiment, 0.7 mm and their width is 0.2 mm. The blind holes 16 are arranged one behind the other on a straight weakening line 30; a bar 18, the length of which is 0.5 mm, is located between two blind holes 16 respectively.

(13) A further straight weakening line 31 is located in parallel to the one weakening line 30 having the blind holes 16 at a distance 32 of 0.7 mm, on which weakening line 31 blind holes 16 of the length 33 of 0.7 mm are also arranged with a bar length 34 of 0.5 mm. The offset between the blind holes 16 on the first weakening line 30 and the blind holes 16 on the second weakening line 31 is 0.6 mm, such that a bar 18 is located at the height of the blind hole 16 of the one line and vice versa. Bars 18 and blind holes 16 are arranged in gaps on the two weakening lines 30, 31.

(14) FIG. 4 shows a microscopic image of the lower side 20 of the weakened spacer fabric 11, in particular of the lower cover layer 13, into which slot-shaped longitudinal blind holes 16 are lasered. The blind holes 16 are located on two parallel weakening lines 30, 31 with an arrangement as described in FIG. 3.

(15) The depicted spacer fabric 11 has a layer thickness of between 1 and 5 mm, the blind hole 16 passing through the lower cover layer 13 and the layer 15 having the spacer threads 14 is 0.5 to 4.5 mm, preferably approximately 4.0 mm deep, and the undamaged upper cover layer 12 is approximately 0.5 mm thick.

(16) The front side 21 of the spacer fabric 11 after the lasering has occurred is depicted in FIG. 5. It can be recognised that the front side 21 having the upper cover layer 12 is undamaged. The darker regions underneath the upper cover layer 12, however, point to the blind hole 16 extending through the layer 15 having the spacer threads 14 up to the lower side of the upper cover layer 12.

(17) In the method according to the invention, for example, a spacer thread 11 made from polyester with a fluorocarbon finishing can be used having a thickness of 3.0 mm, 28 stiches/cm, 8.0 stitch wales/cm according to DIN EN 14971 and 448 end wales/cm.sup.2 having a compression hardness of 12.0 kPa according to DIN EN ISO 3386-1.

(18) Then, a weakening line 30, 31 in the form of blind holes 16 is introduced into the lower side of the spacer fabric 11 by means of a laser (e.g. a UV laser, wavelength 355 nm). Such a blind hole 16 extends from the lower side through the lower cover layer 13 and substantially passes through the layer 15 having the spacer threads 14, wherein the upper cover layer 12 remains substantially undamaged.