Fibre reinforced composites
A molding material comprising a fibrous reinforcement layer and a curable resin matrix. The fibrous reinforcement layer comprises a non-woven fabric comprising a single layer of unidirectional tows arranged at an angle greater than 0° in relation to the lengthwise direction of the fabric and a support structure for maintaining the arrangement of the tows.
1. A two layer molding material having a lengthwise direction, said two layer molding material comprising:
a first layer of dry unidirectional fibers wherein said dry unidirectional fibers are oriented in a direction that is from −30° to −45 with respect to said lengthwise direction, said first layer of dry unidirectional fibers being held together with stitching yarns that extend in said lengthwise direction;
a second layer of resin impregnated unidirectional fibers wherein said resin impregnated unidirectional fibers axe oriented in a direction that is from +30° to +45 with respect to said lengthwise direction, said second layer of impregnated unidirectional fibers being held together with stitching yarns that also extend in said lengthwise direction; and
a curable resin that impregnates said second layer of resin impregnated unidirectional fibers to form a resin matrix therein.
2. A molding material according to claim 1 wherein said dry unidirectional fibers are oriented in a −30° direction with respect to said lengthwise direction and wherein said resin impregnated unidirectional fibers are oriented in a +30° direction with respect to said lengthwise direction.
3. A molding material according to claim 1 wherein said dry unidirectional fibers are oriented in a −45° direction with respect to said lengthwise direction and wherein said resin impregnated unidirectional fibers are oriented in a +45° direction with respect to said lengthwise direction.
4. A molding material according to claim 1 wherein said dry unidirectional fiber and said resin impregnated unidirectional fibers are glass fibers.
5. A molding material according to claim 2 wherein said dry unidirectional fiber and said resin impregnated unidirectional fibers are glass fibers.
6. A molding material according to claim 3 wherein said dry unidirectional fiber and said resin impregnated unidirectional fibers are glass fibers.
7. A molding material according to claim 1 wherein said curable resin comprises an epoxy resin.
8. A molding material according to claim 2 wherein said curable resin comprises an epoxy resin.
9. A molding material according to claim 3 wherein said curable resin comprises an epoxy resin.
10. A molding material according to claim 4 wherein said curable resin comprises an epoxy resin.
11. A molding material according to claim 5 wherein said curable resin comprises an epoxy resin.
12. A molding material according to claim 6 wherein said curable resin comprises an epoxy resin.
13. A molding material according to claim 1 wherein said stitching yarn comprises fibers selected from the group consisting of polyamide fibers and polyethersulfone fibers.
14. A molding material according to claim 2 wherein said stitching yarn comprises fibers selected from the group consisting of polyamide fibers and polyethersulfone fibers.
15. A molding material according to claim 3 wherein said stitching yarn comprises fibers selected from the group consisting of polyamide fibers and polyethersulfone fibers.
16. A molding material according to claim 4 wherein said stitching yarn comprises fibers selected from the group consisting of polyamide fibers and polyethersulfone fibers.
17. A molding material according to claim 7 wherein said stitching yarn comprises fibers selected from the group consisting of polyamide fibers and polyethersulfone fibers.