模具，注塑，注塑成型，是倒模制作的三个工序，例如美术石膏人像、工业生产塑胶花、五金零部件、地盘倒石屎等。

此等工艺操作时常为高温及机器运作，工业意外不少。

"A" side of die for 25% glass-filled acetal with 2 side pulls.

Close up of removable insert in "A" side.

"B" side of die with side pull actuators.

Insert removed from die.

Shell moulding, also known as shell-mould casting, is an expendable mold casting process that uses a resin covered sand to form the mold. As compared to sand casting, this process has better dimensional accuracy, a higher productivity rate, and lower labor requirements. It is used for small to medium parts that require high precision. Shell mold casting is a metal casting process similar to sand casting, in that molten metal is poured into an expendable mold. However, in shell mold casting, the mold is a thin-walled shell created from applying a sand-resin mixture around a pattern. The pattern, a metal piece in the shape of the desired part, is reused to form multiple shell molds. A reusable pattern allows for higher production rates, while the disposable molds enable complex geometries to be cast. Shell mold casting requires the use of a metal pattern, oven, sand-resin mixture, dump box, and molten metal.