Short shot refers to a phenomenon that the plastic injection mould cavity can not be completely filled. Any factors that prevent the polymer melt flow or insufficient injection weight could lead to a short shot phenomenon. These factors include:
1. Melt temperature, mold temperature or injection pressure and speed is too low
2. Uneven plasticizing
3. Adverse air venting
4. Insufficient melt flowability
5. The gate size is too small or plastic product’s wall too thin
How to solve the plastic products short shot
1. Increased melt flow
2. Fill the thick wall first to avoid retention, leading to premature hardening of the polymer melt
3. Increase the number of gates to reduce the flow ratio
4. Increasing the size of the flow channel, reducing the flow resistance
5. Make air venting at appropriate location to avoid air trap
6. Increasing size and quantity of air venting
7. Check the check valve on the injection molding machine and the inner wall of the cylinder for wear, said wear can cause severe injection pressure and injection volume loss
8. Increase the injection pressure
9. Increase injection speed
10. Increase shot weight
11. Increase injection barrel and mould temperature