Compression of moulding sand - using pre-compression by air pressure from closure plate with any mould filling process

摘要

Sand is put in a moulding box contg. a pattern plate, precompressed and finally consolidated by the press, plate. A hollow closure plate sealed against the outside atmos. passes air for pre-compression through the sand and out through the pattern plate, while the closure plate is secured against lifting off the sand but able to move forwards with progressive mould compression. The process gives moulds of uniform density and hardness by a means which are independent of the manner in which sand is put into the mould.