It is not only metals and plastics which can be bent but also wood, particularly when it is laminated. In this latter process, thin layers of wood are glued together and then placed in a former. Clearly preparing several layers of timber is time consuming so thicker pieces of timber can be bent after prior softening by being placed im a steam chamber.

Pressing

Presswork is the term usually applied to pressing metals, but wood glass and plastics are also formed using presses. Metals are pressed at room temperature although they may have to be annealed (heated and cooled slowly to reverse the effects of work hardening) to ensure sufficient malleability. Glass and thermoplastics, however, need to be heated before pressing.
There are two key elements to a press, the punch and the die. These need to be made from a hard material which is resistant to wear and for industrial applications that means a fairly exotic alloy tool steel which can be very expensive.

This technique is used to produce a number of household appliances such as stainless steel kettles, enamelled toasters or large "white goods" such as washing machines. For multi-curved shapes such as car body panels the tooling costs are enormous on account of the complexity of the tooling and the effort required to press such large panels. This means that it is only economically viable for mass production.


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