Plaster mold casting is a metalworking casting process similar to sand casting except the molding material is plaster of paris instead of sand. Like sand casting, plaster mold casting is an expendable mold processes, however it can only be used with non-ferrous materials. It is used for castings as small as 30 g (1 oz) to as large as 45 kg (99 lb). Generally, the form takes less than a week to prepare. Production rates of 1–10 units/hr can be achieved with plaster molds.
Parts that are typically made by plaster casting are lock components, gears, valves, fittings, tooling, and ornaments.
... Plaster casting is similar to sand casting except that plaster of paris is substituted for sand as a mold material ... a production rate of 1–10 units/hr·mold is achieved, with items as massive as 45 kg (99 lb) and as small as 30 g (1 oz) with very good surface finish and ... Plaster casting is an inexpensive alternative to other molding processes for complex parts due to the low cost of the plaster and its ability to produce near net shape ...
... The master record was melted, then taken out of the mold to reveal a negative of the grooves in the metal ... The master mold is used to create "mothers" and these are then further processed to make working molds ... The molds with mandrels placed in the center were heated and dipped in a tank of the molten wax ...
... Plaster mold casting is used when an excellent surface finish and good dimensional accuracy is required ... Because the plaster has a low thermal conductivity and heat capacity the metal cools more slowly than in a sand mold, which allows the metal to fill thin cross-sections the minimum possible ... This results in a near net shape casting, which can be a cost advantage on complex parts ...
Famous quotes containing the words casting, plaster and/or mold:
“For the gods, though slow to see, see well, whenever a man casting aside worship turns folly.”
—Sophocles (497406/5 B.C.)
“The shadow of the Venetian blind on the painted wall,
Shadows of the snake-plant and cacti, the plaster animals,
Focus the tragic melancholy of the bright stare
Into nowhere, a hole like the black holes in space.”
—John Ashbery (b. 1927)
“Death is an incident producing clay. Use it, mold it, learn from it.”
—John Gilling, British screenwriter. Dr. Knox (Peter Cushing)