Vespel

Unlike most plastics,[3] it does not produce significant outgassing even at high temperatures, which makes it useful for lightweight heat shields and crucible support.

However, Vespel tends to absorb a small amount of water, resulting in longer pump time while placed in a vacuum.

[citation needed] Extensive tables of measured thermal diffusivity, specific heat capacity, and derived density, all as functions of temperature, have been published.

Vespel can be processed by direct forming (DF) and isostatic molding (basic shapes – plates, rods and tubes).

For prototype quantities, basic shapes are typically used for cost efficiency since tooling is quite expensive for DF parts.