Composite molded body and manufacturing method thereof

Abstract

Provided are a method for producing a composite molded body, and a composite molded body by the method, wherein: (1) at least one of preforms (a) and (b) which are made of fiber-reinforced thermoplastic resins contains reinforcing fibers having a weight average fiber length of 1 mm or more; (2) a thermoplastic resin (A) is used for the preform (a) and the thermoplastic resin (A) or a thermoplastic resin (B) is used for the preform (b); (3) a thin film of a thermoplastic resin (C) is formed on the surface of either the preform (a) or (b), or on the surfaces of both of the preforms (a) and (b); and (4) the resin (C) and a part of the preforms (a) and (b) are molten by heating while the resin (C) is placed at the boundary surface of the joint, to join the preforms (a) and (b). By setting the crystallization speed of the thermoplastic resin (C) to be relatively slow so that the resin (C) contacts the surfaces of the preforms (a) and (b) at a molten condition for a longer period, a high-strength joint between the preforms (a) and (b) can be achieved.

Description

technical field [0001] The present invention relates to a composite molded body and a method for producing the same, and in particular to heating a preformed body made of a fiber-reinforced resin using a thermoplastic resin to melt a part of the preformed body, and performing a preform at the melted portion. Joining of molded bodies, thereby forming a composite molded body, a method for producing a composite molded body, and a composite molded body produced by the method. Background technique [0002] There are known methods of joining a fiber-reinforced resin of a thermosetting resin and a fiber-reinforced resin of a thermoplastic resin to produce a composite molded body composed of a fiber-reinforced resin as a whole (for example, Patent Documents 1 and 2). Thermoplastic resins themselves and fiber-reinforced resins using thermoplastic resins can be injection molded relatively easily, and thus are superior in moldability and mass productivity compared to thermosetting resi...

AI Technical Summary

Problems solved by technology

As a result, even if a certain amount of heat is applied to melt the surface of the preform, rapid solidification will occur before performing steps such as crimping to achieve good fusion, so the desired level of joint strength cannot be obtained.

Therefore, there is a possibility that the strength and rigidity of the composite molded body as the final molded product cannot reach the target values

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