Lost form (full-mold casting) is a technique similar to investment casting, but instead of wax as the expendable material, polystyrene foam is used as the pattern. The foam pattern is coated with a refractory material. The pattern is encased in a one-piece sand mold. As the metal is poured, the foam vaporizes, and the metal takes its place. This can make complex shaped castings without any draft or flash. However, the pattern cost can be high due to the expendable nature of the pattern.
Minimum wall thicknesses are 2.5 mm, tolerances can be held to .3% on dimensions. Surface finish can be held from 2.5mm to 25mm (0.1in to 1.0 in) rms. Size limits are from 400 g (1 lb) to several tons. No draft allowance is required.
Typical materials that can be cast with this process are aluminum, iron, steels, nickel alloys, copper alloys. Types of parts that can be made using these processes are pump housings, manifolds, and auto brake components.
Sinotech can ensure excellent lost foam castings from China, Taiwan and Korea and is very price competitive. Sinotech has audited, qualified and worked with QS-9000 and ISO certified lost foam factories in China, Taiwan and Korea for over 12 years. Sinotech is dedicated to managing your project on-site and delivering parts to you at lower prices but the same quality, service and terms as a domestic supplier.