1) Process Basics
Gas Assist Injection Molding is a process enhancement to conventional injection molding, involving the injection of high-pressure nitrogen gas into the resin melt-stream immediately after injection of the resin.

The intent is not to cause mixture of the nitrogen and resin, but for the nitrogen to displace resin in flow/gas channels and thicker sections of the molded product. The process is a high speed, low pressure injection method, enabled by “short shooting” the tool and completing the resin filling phase with a second fluid, i.e., nitrogen, at much lower pressures than with conventional injection molding. The three primary considerations for successful application of the technology are

1) repeatability and control of molding parameters on the molding machine,

2) precise control of time and pressure of the nitrogen injection phase, and

3) control of the nitrogen penetration within the molded product. It is important to note that the flow path of the nitrogen in the partially filled tool is primarily controlled by the partial resin fill in the tool cavity, volume of resin, and characteristics of the resin in the tool cavity, not by the nitrogen gas.

2) Advantages of Gas-Assist Injection Molding
The primary reasons for using Gas Assist injection molding methods are the followings
A.Cycle Time Reduction
B.Reduced Part Weight
C.Reduced Resin Costs
D.Expanded Design Options
E.Enhanced Part Strength
F.Quality Improvement
3) Product Applications
A.Part Strength and Rigidity
B.Long Flow Lengths
C.Heavy/Problem Ribs and Bosses
D.Structural Foam Products