PROCESS

Identical to injection molding except that injection and clamp pressures are comparatively low. Liquid nitrogen is introduced to plastic melt. Finished part is filled with small bubbles which make it extremely strong yet lightweight. Platen sizes on this equipment are large (14' x 7' typical) and shot sizes of 150 lbs. or more are not unusual.

RAW MATERIALS

Most widely used raw materials are styrene, polyethylene, polypropylene & polycarbonate. The resin is in the form of pellets before processing.

TOOLING

Machined aluminum.

COST

Part prices are typically low and tooling cost is fairly high because of the size of the parts.

ADVANTAGES

Low piece prices, strong, lightweight parts, extremely large parts possible.

DISADVANTAGES

Relatively expensive tooling; small parts not practical.

EXAMPLES

Swimming pool panels, industrial pallets & material handling containers, stock watering troughs & large toys.