Gas Assist injection moulding technologies

The gas assist injection moulding theories:

  • After mould closing, the plastic is injected to fill or nearly fill the mould cavity.
  • After a selected time delay, first phase is gas injected.
  • Second phase gas penetration to compensate for volumetric shrinkage of the plastic as it cools.
  • A uniform gas pressure is applied throughout the plastic.
  • Gas is exhausted to atmosphere or for recovery before mould opens.
  • Plastic refill commences after the nozzle valve is closed or after the plastic feed gate has solidified.

Gas Assist injection moulding typical applications:

  • The gas flows into the path of least resistance in the thicker sections where the plastic interior is still in a molten state.
  • Gas Assist injection moulding is normally applicable for components in which there are thick and thin sections.

Gas Assist injection moulding advantages

  • Elimination of sink marks.
  • Avoidance of plastic packing from the moulding machine.
  • Reduced in-mould pressures by up to 60%, and therefore reduced press lock forces enabling larger
  • The use of the gas injection moulding as a means of transmitting pressure uniformly throughout the moulding.
  • mouldings on much smaller machines.
  • Reduced power consumption.
  • Reduced moulded in stress, and therefore improved dimensional stability with no distortion.