Full-mold casting

If the volume is large, then the pattern can be mass-produced by a process similar to injection molding.

Pre-expanded beads of polystyrene are injected into a preheated aluminum mold at low pressure.

[3] Full-mold casting is often used to produce cylinder heads, engine blocks, pump housings, automotive brake components, and manifolds.

It is also dimensionally accurate, requires no draft, and has no parting lines so no flash is formed.

He patented the use of foam patterns embedded in traditional green sand for metal casting.