The working principle of Wuhan Hyundai thermosetting plastic injection molding
DATE：2020/8/4 8:43:43 / READ： / SOURCE：This station
The working principle of Wuhan Hyundai thermosetting plastic injection molding
Thermosetting plastics are superior to many thermoplastic materials due to their high heat resistance, excellent electrical properties and large resistance to deformation, so their output and applications have been rising steadily. However, this type of plastic products have long relied on compression molding, resulting in low production efficiency, high labor intensity, and product quality that is not easy to stabilize, which cannot meet the needs of production development. After the 1960s, thermoplastic injection molding was successfully transplanted into thermosetting plastic processing in production, and it was applied. www.handern.com Non-woven equipment
1. Working principle
Thermosetting plastics not only have physical state changes during heating, but also chemical changes. www.handern.com Non-woven equipment
The thermosetting plastic molecules added to the injection machine during injection are initially linear or branched, with reactive groups on the molecular cone, which will first become a less viscous plastic body after being heated in the injection molding machine material. The plunger (or screw) pushes into the cavity. After entering the cavity, the plastic is continuously heated. At this time, the plastic undergoes a cross-linking reaction through the action of the reactive group and the added curing agent, so that the linear resin gradually becomes a body structure, forming a huge molecule, and releasing low molecules during the reaction Substances (such as water, ammonia, etc.). After the product is hardened, it can be taken out of the mold. www.handern.com Non-woven equipment
It can be seen from the above reaction characteristics: (1) The molding temperature must be strictly controlled (when the temperature is low, the plasticization of the material is not good, the fluidity is very poor, and the higher the temperature will make the fluidity decrease or even harden), usually a constant temperature control pin Water heating system: (2) The thermosetting plastic has low molecular weight precipitation during the cross-linking reaction in the mold, so the clamping part of the injection molding machine should meet the requirements of operation: (3) The residence time of the thermosetting plastic in the barrel cannot be too long It is long and strictly prevents premature hardening. Usually, multi-mode replacement can be used. (4) The injection pressure and clamping force of the injection molding machine should be greater than that of the injection molding machine that molds the desirable plastic. www.handern.com Non-woven equipment
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