Instrument panel profits from gas assist

When it comes on the market, be sure to check out the instrument panel for the 1999 Oldsmobile Alero. Nova Chemicals (Calgary, Alberta, Canada) formed part of the team that developed what is said to be the first gas-assisted molding of a one-piece, soft instrument panel substrate.

"The gas-assisted molding process, in concert with Nova's Dylark(reg) resin (a styrene maleic anhydride copolymer), offers a number of process and design benefits," says Ken Oster, General Motors small car engineering group manager. "The rigidity of Dylark, along with the structure of the gas channel, allowed us to minimize the use of steel support, leading to a significant weight reduction. In addition, we were able to consolidate parts as a result of the configuration, while still accommodating the styling theme."

In a conventional molding process, resin is injected into a mold until the cavity is completely filled. In contrast, the gas-assist process requires a gas channel and mold cavity be only partially filled with resin, while the remaining cavity is filled with gas. Utilizing the flow characteristics of Dylark, the technique ensured General Motors it would have a component with the rigidity and structure of solid plastic, without its heavy weight.

Introduction of the gas-assist process in the 1999 Oldsmobile Alero incorporates several other advanced technologies, including the use of sequential gating of multiple resin injection locations.