ABSTRACT
Thermal forming (or thermoforming) is a method where thermal energy provided by a heat source “transforms” a material’s structure and/or shape. Structural material changes occur, for example, during crystallization, sintering, alloying, annealing, decomposition, and pyrolizing. Shaping in thermoforming may be free form, such as in glass blowing and in selective laser sintering (SLS) (see inset in the heading of this chapter). The latter thermoforming method is a rapid prototyping (RP) technique for solid parts, made by solidifying powder-like materials layer by layer through exposure of the surface of a powder bed to a laser beam. However, thermoforming may also involve a step that combines heat and pressure to conform to a final shape in a mold, such as in vacuum forming, a method for thermally shaping a flat plastic sheet into a three-dimensional (3D) shape by heating the sheet and withdrawing the air between the sheet and the mold.
