The working principle of Wuhan Hyundai thermosetting plastic injection molding
DATE:2020/8/7 8:49:50 / READ: / SOURCE:This station
The working principle of Wuhan Hyundai thermosetting plastic injection molding
1. Working principle
The thermosetting material not only changes in physical state during heating, but also chemically changes. The thermosetting plastic molecules added to the injection molding machine during injection are initially linear or branched, with reactive groups on the molecular chain, 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 the reaction is low. Molecular substances (such as water, ammonia, etc.). After the product hardens, it can be taken out of the touch. 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 poor, and the higher the temperature will reduce the fluidity or even harden), usually using constant temperature control Water heating system; (2) Thermosetting plastics have 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 thermosetting plastics in the mold should not be too long , Strictly prevent premature hardening, usually multi-mold 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 of the model thermoplastic material. www.handern.com non-woven equipment www.handern.com non-woven equipment
Author:admin