News
Track information, focus on news
Injection mold exhaust poor how to do?
2023/08/30
Injection molds often have gas, this is what happened? Compared to most people don't know it, let the following small band to understand it!
Pouring system and the air in the mold cavity; Some materials are rich in water that has not been dried and swept away, and they will vaporize into water vapor at high temperatures. Due to the high temperature during injection molding, some unstable plastics will differentiate and generate gas. Some increasing agents in plastic materials may transpiration gases generated by chemical reactions with each other.
The cause of poor exhaust is also required to be found out as soon as possible. Poor exhaust of the injection mold will bring a series of damages to the quality of the plastic parts and many other aspects. The primary manifestation is: in the injection molding process, the melt will replace the gas in the cavity. Assuming that the gas is not discharged in time, the melt will be difficult to fill, resulting in a short injection amount and unable to fill the cavity. The poor gas can be swept away to form a high pressure in the cavity and enter the plastic under a certain degree of contraction, forming a vague, air holes, arrangement of sparse and silver lines and other quality shortcomings;
Because the gas is highly compressed, the temperature in the cavity rises sharply, which leads to the differentiation and baking of the surrounding melt, making the plastic parts present some carbonization and burning. It is mainly at the junction of the two melts and the gate flange. The poor removal of gas makes the melt entering each cavity different in speed, thus easily forming movable marks and fusion marks, and reducing the mechanical function of the plastic part. Due to the obstruction of gas in the cavity, the filling speed will be reduced, the molding cycle will be affected, and the tax payment power will be reduced.
The dispersion of bubbles in plastic parts, the vapor bubbles generated by the accumulation of air in the mold cavity are often scattered on the parts opposite to the gate. Bubbles generated by differentiation or chemical reaction in plastic materials are distributed along the thickness of plastic parts. Bubbles generated by residual water gasification in plastic materials are not regularly distributed on all plastic parts.
Next Page
Previous Page
Website QR Code
WeChat QR Code
Copyright©2023 Wenling Longyi Machinery Co., Ltd. All rights reserved. Powered by www.300.cn SEO
