Molding or moulding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a pattern.
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. The manufacturer who makes the molds is called the moldmaker. A release agent is typically used to make removal of the hardened/set substance from the mold easier.
The terminology can depend on the application. Sand casting involves both a "pattern" (which is the positive-image model of the desired part) and a "mold" (which is the negative-image hole made by packing sand around the pattern).
Types of molding include:
- Compaction plus sintering
- Injection molding
- Reaction injection molding
- Compression molding
- Transfer molding
- Extrusion molding
- Blow molding
- Rotational molding
- Thermoforming
- Vacuum forming, a simplified version of thermoforming
- Laminating
- Expandable bead molding
- Foam molding
- Rotomolding
- Vacuum plug assist molding
- Pressure plug assist molding
- Matched mold