The basic points of designing gas-assisted injection molding

1. Firstly, considering the suitable wall thickness areas needs to be injected and hollowed out, and then decide how to connect them with the gas channel;
2. The gas channel should be arranged in balanced and cannot return back;
3. The layout of the gas channel should be consistent with the main material flow direction, and a larger fillet radius should be used at the corners;
4. The gas nozzle should be placed at the farthest place from the last filling place of the plastic, and placed at the wall thickness area, keeping a distance of more than 20mm from the gate;
5. When the gas is injected, it must be a clear flow direction and it can go to the end of the gas channel;

6. The size of the gas channel is very important, generally 2~4 times than the wall thickness, if the gas channel is too big will cause welding line and air trapping, and if gas channel is too small will cause the gas flow out of control;
7. The cooling should be as even as possible, and the temperature difference between the inner and outer part should be as small as possible, then make a block in half diameter gate area to control the gas flow speed in different directions.

Design principles of plastic injection mold runner system
Jan 6, 20221. Quality first The design of the gating system has a big influence on part quality, firstly the gate should be set at the easiest part of the plastic part to be removed, and at the same time, the...view
Insert pin of vengting design for molded parts
Mar 20, 2022Insert pin of venting: It is difficult to make exhaust slot when end runner is not in parting surface during injection, and there is no matching gap available, but we could make the venting pin at end...view
Parting surface venting of runner system
Mar 10, 2022There are a large amount of gas in the main and sub channel, these gas are discharged through the pull rod (push rod) during injection processing, a part of gas come out from exhaust slot on parting...view
Reasons for making the exhaust system of the injection mold
Feb 28, 2022The gas in the injection mold includes not only the air in the cavity, but also the air in the gate and the decomposition gas generated by the plastic melt, and the steam which caused by plastic in...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
Hydraulic diameter conversion of runners in plastic mold gating system design
Jan 13, 2022Hydraulic diameter refers to 4 times the ratio of the flow cross-sectional area to the perimeter, as the wall shear stress of non-circular pipes is not even distributed along the surrounding walls,...view
English
русский



