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.

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
The design principle of the exhaust slot
Mar 6, 2022The exhaust system of plastic molds is also very important, if the product has air trapping or exhaust system is not suitable will have a big impact on injection molding production and product...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
Gas-assisted injection molding product defects and solutions
Apr 28, 2022Common defects and solutions of gas-assisted injection moulding: 1. Gas blows out the melt like in picture 1. Reason: insufficient pre-filled amount. When the plastic part is a locally thickened...view
Factors affecting the cooling rate of parts by injection molding
Feb 9, 2022It should be shaped by cooling to get stable plastic part after plastic filling the cavity and core side, so most injection molds need to be equipped with cooling devices to make the mold temperature...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
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