LOST FOAM PATTERN FOR CASTING, PRODUCTION OF LOST FOAM PATTERN FOR CASTING AND PRODUCTION OF METAL CASTING

摘要

PROBLEM TO BE SOLVED: To obtain a lost foam pattern for casting with which castings having decreased reside defects are obtainable and which is safe in manufacture and has high accuracy by subjecting a foamable resin formed by impregnating a specifically composed methacrylate and styrene polymerized resin with a foaming agent. ;SOLUTION: The foamable resin is obtd. by impregnating the resin obtd. by polymerizing 2.5 to 45wt.% methacrylate and 97.5 to 55% styrene as essential components with about 1 to 15% foaming agent consisting of an easily volatile org. compd., such as aliphat. hydrocarbon. The foam obtd. by subjecting such foamable resin to expansion molding or the processed foam obtd. by further cutting, or machining and assembling such foam is used as the lost foam pattern for casting. The lost foam pattern is particularly suitable for castings having 25mm thickness in the main thick parts. The contents of the methacrylate are preferably specified to 2.5 to 40% and 2.5 to 35%, respectively, for the castings having the thickness exceeding 15 to 50mm and 50mm. Cast iron and more particularly spheroidal graphite cast iron are cast by using such lost foam pattern, by which the metal castings having the high quality and high accuracy are obtd.;COPYRIGHT: (C)1998,JPO