Views: 1 Author: Site Editor Publish Time: 2022-09-19 Origin: Site
The injection Moulding Machine is a powerful molding machine that uses plastic molding molds to make thermoplastic or thermoset plastic into various plastic products, generally divided into vertical, horizontal, and fully electric. Sometimes, however, the Injection Moulding Machine will not mold, so let's look at some factors that affect the failure of an Injection Moulding Machine.
The injection molding speed is significant for some plastics with messy shapes, significant thickness variations, lengthy processes, and high viscosity, such as resistive ABS. High-speed injection should be considered when high pressure cannot fill the finished product to solve the unsatisfactory shortcomings: improper feed adjustment, lack of material or more material. The amount of filling machine is prohibited, or the filling control system is not operating correctly, the injection cycle is abnormal due to the limitation of the Injection Moulding Machine or mold or operating conditions, the back pressure before the mold is too small, or the material density in the barrel is low. The number of granules with more voids and plastics with significant changes in crystalline specific volume, such as polyethylene, polypropylene, nylon, etc., and plastics with high viscosity, such as ABS, should be adjusted higher, and the amount should be more significant. The material temperature should be adjusted when high.
When there is too much material at the end of the barrel, the screw needs to use the rated injection pressure to compress and push the excess material in the barrel during injection, which significantly reduces the adequate injection pressure of the plastic into the mold cavity and makes it difficult for the finished product to overflow. The injection pressure is too low, the injection time is too long, and the plunger or screw retracts too early. The molten plastic has a high viscosity and poor flowability at low working temperatures and should be injected at high pressure and high speed. For example, when making ABS-colored parts, the colorant's high-temperature resistance limits the barrel's heating temperature, which requires compensation for higher than usual injection pressure and longer injection time.
The front end of the barrel of the Injection Moulding Machine has a low temperature, and the melt entering the cavity is too viscous because of the cooling effect of the mold, which makes it challenging to move prematurely and hinders the filling of the distal end of the mold; the rear part of the barrel has a low temperature, which makes it difficult for the thick plastic to move and prevents the screw from moving forward, resulting in a pressure that appears to meet the pressure shown on the pressure gauge. In contrast, the melt enters the cavity at low pressure and speed. Low pressure and low speed into the cavity may block the mold feeding channel; if the mold is without cold material well, with a self-locking nozzle, choose the post-filling program, the nozzle can adhere to the necessary temperature; when the machine is too cold nozzle sometimes can use a flame gun to do external heating to speed up the nozzle warming.