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.

Plastic injection mold common cooling gate
Feb 17, 20221. Straight-through cooling water gate: the straight-through cooling gate is the most commonly used gate for plastic injection mold, and it is also the most convenient type of cooling for processing....view
Conformal cooing channel of plastic injection mold
Feb 23, 2022The conformal cooling gate is a new type of mold cooling gate based on 3D printing technolog, because of its processing characteristics, the conformal cooling gate can fit the shape of the product...view_20250317091228A019.jpg)
Main application of gas-assisted molding technology
Apr 7, 2022Gas-assisted molding has a particularly obvious effect on the material saving of tubular and rod-shaped plastic parts, such as car handles, seat armrests, window frames, and wood-like furniture, the...view
The main reasons for air trapping of plastic injecton mold
Mar 1, 2022During 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...view
Pin-point gate of plastic injection mold runner system design
Jan 24, 2022In order to get the best injection quality, the gate type must be selected carefully, the coommon gate tyeps are: direct gate, side gate, pin-point gate, sub gate,valve gate of hot runner etc. Among...view
What is Called Draft Angle?
Dec 29, 2021The draft angle is also called demold angle and angle which is used for product removal from the mold and designed on the parting surface, the angle is called draft angle which shows in picture 1....view
English
русский



