MULTIAXIAL TEXTILE FABRIC WITH DISCONTINUOUS INTERMEDIATE LAYER

Abstract

A multiaxial textile fabric has at least two thread layers and at least one nonwoven layer. Each thread layer is made of multifilament reinforcement yarns arranged parallel to one another and so as to lie adjacently next to one another within the thread layers, wherein at least one thread layer is at least partially directly contacted by the nonwoven layer, and cut-out sections are provided within the nonwoven layer, the cut-out sections having a size of at least 4 mm.sup.2. The multiaxial textile fabric also includes a fiber-reinforced composite material.

Claims

1. A multiaxial non-crimp fabric with at least two thread layers and at least one non-woven layer, wherein each thread layer is formed by multifilament reinforcing yarns arranged parallel to one another and next to one another abutting on one another within the thread layers, wherein at least one thread layer at least partially directly touches with the non-woven layer, wherein cutouts are provided within the non-woven layer, wherein the cutouts have an area of at least 4 mm.sup.2 and the non-woven layer is a discontinuous layer at least due to the cutouts.

2. The multiaxial non-crimp fabric according to claim 1, wherein the cutouts are arranged regularly or randomly irregularly in the non-woven layer.

3. The multiaxial non-crimp fabric according to claim 1, wherein the cutouts have same or different shapes and/or sizes.

4. The multiaxial non-crimp fabric according to claim 1, wherein the non-woven layer has a conductive material, wherein the conductive material is applied to and introduced in the non-woven layer by means of powder and/or particles and/or the non-woven layer has conductive fibers.

5. The multiaxial non-crimp fabric according to claim 1, wherein the non-woven layer has a binder which has a particle size of 50-160 μm and/or the non-woven layer has a thickness which is less than 40 μm.

6. The multiaxial non-crimp fabric according to claim 1, wherein the non-woven layer has 70% continuous fibers with a fiber length of more than 20 m and/or the non-woven layer has 70% short fibers with a fiber length in the range of 8 to 15 mm.

7. The multiaxial non-crimp fabric according to claim 1, wherein the multifilament reinforcing yarns are carbon yarns with a strength of at least 5000 MPa, measured according to JIS-R-7608, and a tensile modulus of at least 260 GPa, measured according to JIS-R-7608, and/or carbon fiber yarns with a strength of at least 4500 MPa, measured according to JIS-R-7608, and a tensile modulus of at least 240 GPa, measured according to JIS-R-7608.

8. The multiaxial non-crimp fabric according to claim 1, wherein the non-woven layer has a polyester.

9. The multiaxial non-crimp fabric according to claim 1, wherein the non-woven layer has a thermoplastic polymeric material, wherein the thermoplastic polymeric material comprises a first polymeric component and a second polymeric component whose melting temperatures are below the melting or decomposition temperature of the multifilament reinforcing yarns, wherein the first polymeric component has a lower melting temperature than the second polymeric component and the first polymeric component is soluble in epoxy, cyanate ester, or benzoxazine matrix resins, or in mixtures of these matrix resins and the second polymeric component is not soluble in epoxy, cyanate ester, or benzoxazine matrix resins, or in mixtures of these matrix resins.

10. The multiaxial non-crimp fabric according to claim 9, wherein the first polymeric component has a melting temperature in the range between 80 and 135° C. and the second polymeric component has a melting temperature in the range between 140 and 250° C.

11. The multiaxial non-crimp fabric according to claim 9, wherein the second polymeric component is a polyamide homopolymer or polyamide copolymer or a mixture of polyamide homopolymers and/or polyamide copolymers.

12. The multiaxial non-crimp fabric according to claim 11, wherein the polyamide homopolymer or copolymer is a polyamide 6, polyamide 6.6, polyamide 6.12, polyamide 4.6, polyamide 11, polyamide 12, or polyamide 6/12.

13. The multiaxial non-crimp fabric according to claim 9, wherein the first polymeric component is a polymer that chemically reacts with epoxy, cyanate ester, or benzoxazine matrix resins upon crosslinking of these matrix resins.

14. The multiaxial non-crimp fabric according to claim 9, wherein the first polymeric component is a polyhydroxyether.

15. The multiaxial non-crimp fabric according to claim 9, wherein the non-woven layer contains the first polymeric component in a fraction of 20 to 40 wt. % and the second polymeric component in a fraction of 60 to 80 wt. %.

16. A layer structure, wherein the layer structure has at least one multiaxial non-crimp fabric according to claim 1.

17. A fiber reinforced composite material, wherein the composite material is formed from at least one layer structure according to claim 16 and a further matrix material.

Description

[0047] The invention is explained in more detail on the basis of figures.

[0048] FIG. 1 schematically shows an embodiment of a non-woven layer with slits, which is not according to the invention.

[0049] FIG. 2 schematically shows various slit forms which are also not according to the invention.

[0050] FIG. 3 A and B schematically show an embodiment of a non-woven layer with cutouts.

[0051] FIG. 4 schematically shows a non-woven layer with cutout rows.

[0052] FIG. 5 schematically shows a non-woven layer with a cutout which has emerged due to material displacement.

[0053] FIG. 1 shows an embodiment not according to the invention with slits in the non-woven layer 1. FIG. 1 schematically shows a portion of a slit pattern of a non-woven layer 1. The non-woven layer 1 has slit rows 2 with slits 3 approximately perpendicular to the laying direction A of the fibers. In the figure, the slits 3 are formed as longitudinal slits, wherein their longitudinal extension extends parallel to the longitudinal extension of the slit row 2. Within a slit row 2, the slits 3 have a distance AS from one another. The slit rows 2 have a distance ASR from one another. Adjacent slit rows 2″, 2′ can have slits 3′, 3″ which have an offset V from one another. In FIG. 1, the offset V is provided alternately for every second slit row 2 so that the position of the slits 3 of one slit row 2 and a next but one slit row 2″′ are at the same height perpendicular to the longitudinal extension of the slit rows 2. In FIG. 1, the slits 3 have a length L. Due to the offset V of the slits 3, 3′ and 3″, a free section VF results. If the discontinuous fibers are first formed due to the slits 3 in the non-woven layer 1, the fibers of the non-woven layer 1 can at most run over the section VF before they are separated due to a slit 3. It is understood that the length of the discontinuous fiber of the non-woven layer 1 can be longer than VF, as the fiber within the non-woven layer can be present corrugated/curved.

[0054] FIG. 2 also shows an embodiment not according to the invention. FIG. 2 schematically shows different shapes of the slits 3. In FIG. 2 A, the slits 3 are transverse slits whose longitudinal extension is substantially perpendicular to the longitudinal extension of the slit row 2. In FIG. 2 B the slits 2 have a cross shape 4 with two incisions 5 5′, wherein one incision 5′ runs parallel to the longitudinal extension of the slit row 2. In FIG. 2 C the slits 3 are configured in a star shape 6, the star shape 6 having at least two incisions 5, 5′. In the case of two incisions 5, 5′ in star shape 6, none of the incisions 5, 5′ is arranged parallel or perpendicular to the longitudinal extension of the slit row 2. In general, the star shape 6 consequently differs from the cross shape 4 in that it has at least one incision 5 arranged at an angle to the longitudinal extension of the slit rows 2.

[0055] Different shapes of slits 3 can be present within a non-woven layer 1. The different slit shapes can also be present within a slit row 2.

[0056] In FIG. 3 A, a non-woven layer with cutouts 7 in combination with slits in star shape is schematically depicted. The cutouts 7 have emerged, for example, by material being punched out of the non-woven layer 1.

[0057] In FIG. 3 B, two possible types of cutouts 7 for the non-woven layer 1 are depicted. The cutouts 7 can be oval 7.1 or round 7.2, wherein a single type of cutout 7 or a mixture of different types of cutouts 7 can be present within the non-woven layer 1. However, all cutouts 7 of this type have in common that material has been removed from the non-woven layer 1.

[0058] FIG. 4 schematically shows cutout rows 8 with cutouts 7. Within a cutout row 8, the cutouts 7 have a distance AS from one another. The cutout rows 8 have a distance ASR from one another. Adjacent cutout rows 8′, 8″ can have cutouts 7′, 7 which have an offset V from one another. In the embodiment example in FIG. 4, the offset V is provided alternately for every second cutout row 2 so that the position of the cutouts 7 of a cutout row 8 and a next but one cutout row 8″′ are at the same height perpendicular to the longitudinal extension of the cutout row 8. In FIG. 4, the cutouts 7 have a length L. Due to the offset V of the cutouts 7′, 7″ and 7″′, a free section VF results. If the discontinuous fibers are first formed due to the cutouts 7 in the non-woven layer 1, the fibers of the non-woven layer 1 can at most run over the section VF before they are separated due to a cutout 7. It is understood that the length of the discontinuous fibers of the non-woven layer 1 can be longer than VF, as the fibers within the non-woven layer can be corrugated/curved.

[0059] FIG. 5 schematically shows a detailed portion of a non-woven layer 1 with cutout 7, in which the cutout 7 is formed by displacement of fiber material within the non-woven layer 1. In the embodiment example, the fibers 9 within the non-woven layer 1 are deflected (shifted) such that an opening or hole emerges within the non-woven layer 1 so that a cutout 7 is formed. The cutout 7 is to have a size of at least 4 mm.sup.2, which means that the hole or opening is to have a contiguous area of at least 4 mm.sup.2. A contiguous area is given if the cutout 7 is not interrupted by non-woven material such as a plurality of fibers.