Thermosetting plastic injection transfer moulding method and its mould

Abstract

The invention provides a thermosetting plastic injection molding method and a mold thereof, belonging to the technical field of mechanochemical industry. It solves the problems of the existing thermosetting plastic injection molding method that there is residual waste in the runner and the gate and serious waste. The injection molding method of the thermosetting plastic comprises the following steps: A, melting; B, preliminary mold closing; C, injection; D, pressure mold closing; The present invention also provides a mold used in the thermosetting plastic molding method, which includes an upper mold, a lower mold and a guide mechanism, and an ejection mechanism for ejecting a product is arranged between the lower mold cylinder and the lower mold plate. An insert ring is arranged on the outer side of the contact between the upper die core and the lower die core, and the insert ring, the upper die core and the lower die core form a feeding cavity of the mold. The method has high material utilization, high production efficiency, long service life, compact structure and convenient processing.

Description

technical field [0001] The invention relates to a molding method of plastics and a mold used therefor, and is aimed at a molding method of thermosetting plastics and the mold used therein. Background technique [0002] At present, thermosetting plastics have been widely used in cooking utensils, electrical appliances, and auto parts. There are usually only two production processes for thermosetting materials, one is compression molding and the other is injection molding. These two processes have their own advantages and disadvantages. Compression molding is to weigh the raw materials and add them to the feeding cavity of the compression mold, the mold is closed and heated, the material melts and flows, the equipment is further pressurized, and the thermosetting material is pressed and heated in the heated mold cavity to cross-link and solidify. Its advantages are: simple equipment, mold, and process, because the mold has no runner gate, and the material is weighed and fed, ...

AI Technical Summary

Problems solved by technology

But this process also has great disadvantages: the material needs to be manually weighed and fed, and the material still has a heating and softening process in the cavity, resulting in a long molding cycle and low production efficiency. Harsh conditions and high labor intensity

But there are also certain disadvantages: since the molten thermosetting plastic is injected into the mold cavity through the main runner, runner and gate of the mold, the solidified material in the main runner and runner is wasted, so that the utilization of materials Due to the existence of the gate, there are defects on the surface of the product, which affects the appearance; because the material enters from the gate, the material flow has obvious directionality, and the internal stress of the product is large; due to the high flow rate of the material at the gate, the mold here is extremely Easy to wear

This patent application also discloses the structure of a mold that completes this process. This technology integrates injection and pressing processes, but there are still runners and gates. After one cycle, the remaining waste materials in the runners must be discarded. Waste Seriously, at the same time, it can be seen from its technical scheme that the plastic mentioned is a thermoplastic, and its molding method is very different from that of a thermosetting plastic.

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