Patterns and models are used within the casting process in order to create the required cavity in the mould. They are complete replicas of the component to be cast and can be made from a number of materials including wood, plastic, metal or wax. Typically, patterns and models are machined, as this allows for precise replication of the shape of the required component.
Within casting techniques such as sand casting and shell moulding, the mould cavity is created by placing the pattern into the mould and tightly packing sand around it. Once this process is complete, the pattern is then removed from the mould. Within the investment/lost wax casting process, a wax model of the component is produced, which is then dipped in ceramic and heated so that the ceramic solidifies and the wax melts, before draining out of the ceramic, leaving behind the required mould cavity.
Used to produce
Typically, patterns and models are machined, as this allows for precise replication of the shape of the required component.