In gas assist molding, the gas will displace the polymer in thicker areas to hollow out the part. The nitrogen gas does not mix with the resin, but instead forms a continuous channel through the hotter, less viscous sections of the melt stream. The gas maintains internal pressure throughout the cooling cycle.
The process is a low-pressure injection method. A “partial fill” method of resin fill is used. The gas is then utilized to fill and pack out the remainder of the part. The nitrogen is typically injected into the process at relatively low pressures. At DeKALB, we utilize Uniloy Springfield Structural Web and Bauer Gas Assist technologies in our processes.
Key Benefits of the Gas Assist Molding Process
- Design freedom utilizing thick and thin wall sections
- Hollow gas channels increase stiffness and reduce cooling time
- Improved aesthetics (low warp, no sink marks, etc.)
- Reduced cavity pressure equals lower tonnage, more efficient machines
- Significantly reduced cooling and overall cycle time
