Views: 3 Author: Site Editor Publish Time: 2022-10-24 Origin: Site
The indentation of injection mold products mainly appears in the thick-wall position, reinforcement, housing, the back of the nut insert, etc., because of the shrinkage depression caused by the cooling and hardening of plastic, the so-called indentation is the cooling slow part in the direction of bubble contraction to produce a conspicuous concave surface. Molding shrinkage of large material indentation is also large, such as polyethylene PE, polypropylene PP, even if only a little reinforcement, will produce indentation.
I. Injection molding equipment:
Reasons: the gate is too small or the runner is too narrow or too shallow, the runner is low efficiency, high resistance, premature melting cooling, the gate is too large, the material loses the shear rate, the material has high viscosity, also can not make the product full; The gate should be set up in the thick-walled part of the product in process, the cooling system of the mold is not reasonable, the injection, the pressure holding pressure is too small, the injection speed is too low, the mold temperature is too low, the injection glue residual amount is too small or no residual amount, the raw material is too soft.
1. Check the mold temperature. If the product is shrunk because the glue level is too thick, the temperature should be reduced. If the product is due to the glue is too thin and shrink, should improve the degree here.
2. Appropriately increase the holding pressure or extend the holding time.
3. For products with too thin glue position, try to improve the glue shooting speed.
4. Selecting the gate position of injection mold products at the thickest glue position can improve shrinkage.
5. Uniform wall thickness of injection mold products can improve shrinkage.
Two, injection mold:
(1) the gate is too small or the runner is too narrow or too shallow, the runner efficiency is low, the resistance is large, the melt is cooled prematurely;
(2) Multi-gate injection mold should adjust the filling speed of each gate, and it is best to open the gate symmetrically;
(3) The key parts of the injection mold should be effectively set up the cooling channel, to ensure that the cooling of the mold to eliminate or reduce shrinkage plays a very good effect;
(4) The whole injection mold should be free of burrs and have reliable sealing property, which can withstand the mold filling of high pressure, high speed and low viscosity melt.
The MISSION OF FSTAD IS TO MASTER THE CORE TECHNOLOGY OF injection MOLDING production, communicate and analyze the technology before mold production with customers from the production needs of finished products, so that the mold delivery time is short, the life is long, the rapid mass production and the finished product quality is excellent! Is there a high frequency of injection mold products with dents? We just need to think more and summarize when encountering such problems. Of course, we also hope that this article from Fansstad can provide you with some help. Injection mold needs, remember to find Fansstad!