Structural foam molding is a great option for large, thick parts. The injection molding process creates parts that are structurally sound, light weight, and are less likely to warp.
How Structural Foam Molding Works
A foaming agent is mixed with part resin while still in pellet form. As the resin and foaming agent is heated by the barrel and injected into the mold, the foaming agent turns into gas. Less material is required because the gas bubbles expand until the cavity is filled. As the material pushes against the wall of the mold it creates a thick skin while leaving the inside of the part with a cellular like structure. The part is ejected and the process repeats.