Short shots are a phenomenon in which the mold cavity cannot be completely filled.
Plastic Injection Molding-Short Shots
Causes:
(1) Die temperature, material temperature, or injection pressure and speed are too low
(2) Uneven plasticization of raw materials
(3) Poor exhaust
(4) Insufficient liquidity of raw materials
(5) The part is too thin or the gate size is too small (6) Polymer melt is prematurely cured due to unreasonable structural design
Remedies:
Material: Use more fluid materials
Mold design:
(1) Fill the thick wall before filling the thin wall to avoid the retention phenomenon.
(2) Appropriately increase the number of gates and runner size to reduce the process ratio and flow resistance
(3) The position and size of the exhaust port should be properly set to avoid the phenomenon of poor exhaust.
Machine:
(1）Check whether the check valve and the inner wall of the material cylinder are seriously worn
(2) Check if the feeding port has material or whether it is bridged.
Process:
(1) Increase injection pressure and injection speed to enhance shear heat
(2) Increase the amount of injection
(3) Increase material cylinder temperature and mold temperature
