What type of moulding is characterized by heating and forcing material into a cavity?

The correct type of moulding characterized by heating and forcing material into a cavity is transfer moulding. In this process, preheated material is loaded into a chamber and then forced into a mould cavity under pressure using a plunger. The heat helps the material to flow into the intricacies of the mould, allowing for the creation of complex shapes and details. After the material fills the mould, it then cures to form a solid object.

Understanding transfer moulding is essential as it is particularly effective for thermosetting plastics, which require heat to cure. The other moulding processes do not involve this specific method of heating and forcing material into a cavity in the same manner. For instance, blow moulding involves inflating hot air into a pre-formed plastic tube to create hollow objects, while injection moulding forces molten material directly into a mould under high pressure but does not necessarily require the initial pre-heating step of transfer moulding. Rotational moulding, on the other hand, involves the rotation of a mould to create hollow objects without any high-pressure forcing action. Each of these methods has its particular uses and benefits, but transfer moulding is distinct in its approach of heating and subsequently forcing the material into a cavity.