Discontinuous long fiber reinforced thermoplastic composite material mold pressing precast body and preparation method thereof

Abstract

The invention provides a discontinuous long fiber reinforced thermoplastic composite material mold pressing precast body and a preparation method thereof. The mold pressing precast body comprises slices formed by slitting / cutting of continuous fiber reinforced thermoplastic composite material preimpregnated sheets / preimpregnated yarns, wherein the length L range of the slices is 5-200 mm, the width W range of the slices is 2-30 mm, and the weight percentage content of fibers in the slices is 20-90 wt%; and high-strength isotropous complicated parts with high size stability can be prepared through secondary mold pressing of the precast body, so that the defects of easy warpup, fiber length loss, weaker part performances, anisotropic mechanical performances of continuous fiber reinforced composite materials and difficult machining of different-thickness complicated parts after mold pressing injection molding of short-fiber and long-fiber particles are made up.

Description

technical field [0001] The invention belongs to the field of thermoplastic composite materials, and relates to a fiber-reinforced thermoplastic composite material prefabricated body suitable for secondary processing in a compression molding process and a preparation method thereof. Background technique [0002] In recent years, fiber-reinforced thermoplastic composites have been widely used in aerospace, ships, rail transit and other fields because of their light weight, excellent mechanical properties, and secondary processing. To achieve the research direction of automobile lightweight, however, how to take into account the mechanical properties and efficient formability of high-performance fibers has become a key node in meeting the requirements of fast and efficient production cycle in the production of auto parts. [0003] Patent CN 102837429 B discloses an oriented discontinuous fiber prepreg and its preparation method, which solves the problem of easily forming wrinkl...

AI Technical Summary

Problems solved by technology

Solved the poor mechanical properties of short-fiber thermoplastic composite materials; solved the problem that long-fiber-reinforced thermoplastic composite materials cannot achieve isotropy, easy to shrink, easy to deform, and the initial length cannot be retained in the part during the molding process. Mechanical properties The low level limits the possibility of manufacturing high modulus and high precision products; it solves the anisotropy of continuous fiber reinforced thermoplastic composite materials, and the interlayer shear force is weak, which makes it impossible to process products with unequal thickness and difficult to form complex curved surfaces and structural shapes. high cost

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