Some plastic parts quickly swell or swell on the back of the metal insert or in a particularly thick part after the mold is demolded. This is because the plastic that is not completely cooled and hardened is caused by the release of gas under the action of the pulsation.
(1) Effective cooling. Reduce the mold temperature, extend the mold opening time, and reduce the drying and processing temperature of the material.
(2) Reduce the filling speed, reduce the forming cycle, and reduce the flow resistance.
(3) Increase the pressure and time of holding pressure.
(4) Improve the condition that the wall surface of the workpiece is too thick or the thickness changes greatly.