Tin soldiers being cast in German molds from the early 20th century. The two mold halves are clamped together, and the metal (an alloy of tin and lead, heated to approx. 300 °C) is poured into the mold. When the metal has solidified, the mold is cracked open. Sprues (pouring channels) and extraneous flash (metal that has penetrated cracks and air channels in the mold) are seen in the third image, and have been removed from the castings in the last image.
Molding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a mold. A mold or mould is a hollowed-out block that is filled with a liquid like plastic, glass, metal, or ceramic raw materials. The liquid hardens or sets inside the mold, adopting its shape. A mold is the opposite of a cast (see casting). The manufacturer who makes the molds is called moldmaker. A release agent is typically used to make removal of the hardened/set substance from the mold easier. Types of molding include:
- Powder metallurgy and ceramics
- Compaction plus sintering
- Plastics
- Injection molding
- Compression molding
- Transfer molding
- Extrusion molding
- Blow molding
- Rotational molding
- Thermoforming
- Vacuum forming, a simplified version of thermoforming
- Reaction Injection Molding
- Laminating
- Expandable bead molding
- Foam molding
- Rotomolding
- Vacuum plug assist molding
- Pressure plug assist molding
- Matched mold
