About Gas Assist Injection Molding

Gas assist injection molding is a variation of conventional injection

molding that can be easily retrofitted to an existing injection

press by the addition of an auxiliary gas unit. The usual injection
of molten plastic is assisted by the introduction of pressurized gas
(usually nitrogen) into the mold. The gas produces a bubble which
pushes the plastic into the extremities of the mold creating
hollow sections as the bubble propagates.
Gas assist molding offers a variety of process and design features
which can help to meet application requirements.