Precision injection molding polyamide composite and preparation method thereof

Abstract

The invention provides a precision injection molding polyamide composite, which comprises the following components in percentage by weight: PA6 or PA66 40-60, E-type glass fiber 40-55, nucleating agent 0.1-0.3, flowable agent 0.1-0.3 and antioxidant 0.1-0.3, wherein the nucleating agent is calcium carboxylate of which the main ingredients are long carbon chains; the flowable agent is an optimized mixture of copolymers and montanic acid derivatives; and the antioxidant is an inorganic phosphate. The polyamide composite provided by the invention has the advantages that: a batch of small precision plastic injection-molded parts can be molded by the pin-hole injection at one time; degating is avoided and demolding is easy; meanwhile, the physical properties such as thermal deformation temperature, rigidity and transparency are improved and the dynamic performance such as elasticity bending modulus and impact strength is also improved.

Description

technical field [0001] The invention relates to the technical field of precision injection molding, in particular to a precision injection-grade polyamide composite material and a preparation method thereof, which is specially used for preparing small-scale precision injection castings in the fields of electronics and communications. Background technique [0002] Most of the plastic electronic components are injection molded. In recent years, with the rapid development of electronics, communications and other industries, people's requirements for high precision and high performance of small precision plastic castings are increasing day by day. The traditional plastic molding process has been difficult to meet the current high requirements. According to the requirements of the standard, precision injection molding technology must be used. [0003] Precision injection molding requires that the product not only has high dimensional accuracy, low warpage deformation, excellent t...

AI Technical Summary

Problems solved by technology

However, general-purpose polyamide plastics, such as: nylon 6 (PA6) and nylon 66 (PA66), etc., during processing, due to the high crystallinity of polyamide plastics, the crystallization speed is slow, the cooling time is long, the shrinkage rate changes greatly, and the demoulding Defects such as difficulties

If the polyamide plastic reinforced with glass fiber is cooled for a long time during the molding process, it will completely crystallize, and the crystallization will make the plastic brittle (decrease in impact resistance), poor toughness and poor ductility, and it will easily break the water outlet.

At the same time, due to the high crystallinity of crystalline polymers, the volume change after cooling is large, so the shrinkage increases, resulting in difficulty in demoulding, and it is impossible to inject a batch of small precision plastic castings at one time.

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