Sheetlike composite material

Abstract

A sheetlike composite material including at least one layer A of a nonwoven thermoplastic fibre web or a thermoplastic film, and at least two unidirectional oriented-fibre layers B and B′, the layers B and B′ having a bidirectional fibre orientation. The layers are not only needled but also stitched to one another.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is the U.S. National Phase of PCT / EP2013 / 052616 filed Feb. 8, 2013, which claims priority to European Patent Application No. 12154516.4 filed Feb. 8, 2012, the disclosures of which are incorporated in their entirety by reference herein.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention relates to a planar composite material containing two differently oriented unidirectional fiber-reinforced layers and at least one non-woven thermoplastic fiber layer or thermoplastic foil layer, stitched and needled to each other, and to a process for its production and to its use.[0004]2. Description of the Related Art[0005]Thermoplastics are increasingly used for producing molded parts, particularly components for automobiles, due to their low weight. To provide them with a sufficient strength and rigidity they are usually compounded with reinforcing fibers. For example, planar semifinished products are produced...

AI Technical Summary

Benefits of technology

The patent describes a new type of material made up of layers made of fiber nonwoven or thermoplastic foil, and unidirectional fiber layers made of parallel reinforcing fiber bundles. These layers are stitched and needled to each other, creating a planar composite material that is strong and durable. The technical effect of this invention is the creation of a composite material that has improved strength and durability compared to traditional materials made of fiber nonwoven or thermoplastic foil.

Problems solved by technology

However, in this process the fiber reinforcement is nondirectional, i.e., it acts equally in all directions with no preferred direction so that the strength of such composites is limited.

In this process, however, the fiber bundles are not opened so that the thermoplastic melt can soak the woven or oriented fiber layer only incompletely, thus resulting in a lower loading capacity of the components produced therefrom.

However, in woven fabrics the fiber bundles are undulated at the crossing points, thus resulting in a reduction of the compressive strength in the fiber direction.

These dry spots result in an irregular impregnation.

Aramide fibers are high performance reinforcement fibers made of an aromatic polyamide that in contrast to the aliphatic polyamides cannot be melted and, therefore, cannot be thermoplastically processed.

Images