Mat made from natural fibres and glass
The invention relates to a mat comprising discontinuous natural fibers and discontinuous glass fibers, and to the fibrous structures that can be produced using said mat, said structures being intended to reinforce composites. The presence of natural fibers in the mat gives the latter the property of being easy to handle, especially by eliminating the annoying tendency of mats made exclusively of glass fiber to wrinkle uncontrollably. In addition, the mechanical properties of the final composite are remarkable, in particular with regard to the tensile modulus and flexural modulus.
1 . A mat comprising a homogeneous mix of fibers which is comprised of discontinuous natural fibers and discontinuous glass fibers.
2 . The mat as claimed in claim 1 , wherein the fibers comprise 10 to 90% by weight of natural fibers.
3 . The mat as claimed in claim 2 , wherein the fibers comprise 30 to 70% by weight of natural fibers.
4 . The mat as claimed in claim 1 , wherein the fibers comprise 10 to 90% by weight of glass fibers.
5 . The mat as claimed in claim 4 , wherein the fibers comprise 30 to 70% by weight of glass fibers.
6 . The mat as claimed in claim 1 , wherein the fibers consists of glass fibers and natural fibers.
7 . The mat as claimed in claim 1 , wherein the natural fibers are flax fibers.
8 . The mat as claimed in claim 1 , wherein the natural fibers have a length of less than 150 cm.
9 . The mat as claimed in claim 1 , wherein the glass fibers have a length ranging from 10 to 200 mm.
10 . The mat as claimed in claim 1 , wherein the fibers are mechanically bonded.
11 . The mat as claimed in claim 10 , wherein the fibers are bonded by needle punching.
12 . The mat as claimed claim 11 , wherein the fibers are separated, and said fibers are carded and/or web-formed before needle punching.
13 . The mat as claimed in claim 1 , wherein the mass per unit area of the mat ranges from 100 to 900 g/m 2 .
14 . A fibrous structure comprising several fabric layers mechanically and/or chemically linked together, wherein at least one of the layers is the mat as claimed in claim 1 .
15 . The structure as claimed in claim 14 , wherein at least one of the layers is a continuous-strand mat.
16 . The structure as claimed in claim 14 , wherein at least one of the layers is a chopped-strand mat.
17 . A composite material comprising a mat, wherein said mat comprises a homogeneous mix of fibers which comprises discontinuous glass fibers and discontinuous natural fibers, and a matrix comprising a thermosetting resin.
18 . The composite material as claimed in claim 17 , wherein the resin is a polyester.
19 . The composite material as claimed in claim 17 , wherein the fibers consists of discontinuous glass fibers and discontinuous natural fibers.
20 . The composite material as claimed in claim 17 , wherein the mat comprises 10 to 90% by weight of natural fibers and 90 to 10% by weight of glass fibers.
21 . The composite material as claimed in claim 20 , wherein the mat comprises 30 to 70% by weight of natural fibers and 70 to 30% by weight of glass fibers.
22 . The composite material as claimed in claim 20 , wherein the only fibrous structure of the composite material is the mat.
23 . A process for manufacturing the composite material as claimed in claim 17 , comprising
forming the mat in a mold, and then impregnating the mat with a thermosetting resin.