English
русский
The main reasons for air trapping of plastic injecton mold
During the injection molding process, the front end of the slight ribs may be air trapped and plastic burnt, and also cause the molded part may become black and carbonized.
The mechanism of air trapped scorching is that when the air in the mold cavity is extruded by the molten plastic flowing into the cavity, the air will heat due to being compressed if it is in a sealing state without an outlet, and then it leads to combustion and burns.
Since the air is a kind of gas, it can be compressed, but it generates heat when compressed, it is like when we use a pump to inflate our bike tires, the pump gets hot.
The compression of the residual air in the cavity usually occurs in a short time of about 0.1 to 0.5 seconds, because it is compressed under a high pressure of 200 to 500 kgf per square centimeter, it is easy to heat up to the ignition point of the plastic (as shown in picture 1).
Therefore, for some slight ribs, pillars and other product features in the gas injection mold, it is necessary to make venting slot to let the gas in the mold which can be discharged to the outside of the cavity.
_20250310164515A048.webp "Plastic Switch Mould")
Plastic injection mold runner system design
Jan 16, 2022The gate is the connecting part between the runner and the cavity, and is also the end part of the injection mold gating system, the molten plastic enters the cavity and core side through the gate...view
Venting insert design of molded parts
Mar 13, 2022In the thin-walled cavity, the end of the melt flow, the bottom of the blind hole of the mold cavity, the end of the solid column of the plastic part, the bottom of the plastic part rib and screw...view
Temperature system of injection mold
Feb 8, 2022Hi everyone,the mold cooling time is the longest during injection, so the design of mold temperature system controlling is very important, we will talk about mold cooling, heating system in following...view
Water assisted injection molding introduction
May 11, 2022Like the gas-assisted injection molding process, water-assisted injection molding injects a piece of plastic into the mold cavity and core firstly, and then injects water to squeeze the melt plastic...view
The principle of mold temperature balance in plastic mold cooling system design
Feb 21, 2022The principle of mold temperature balance: 1. Due to the complexity of the plastic parts and mold structure, it is difficult to make the temperature of the mold completely consistent, but should be...view
The design requirements of slider wear plate
Jan 2, 20241. The wear plate of slider requires hardening treatment, with a hardness of 45-48HRC; 2. The friction surface of the wear plate is required to be 1.0mm higher than the slider surface (see picture-1);...view