Eldredge D, Mclntyre S.

Abstract: Shell molding was developed by Johannes Croning in Germany during World War-2. The process was uncovered by the U.S. Military during a search of the German Patent Office at the end of the war. The basic process consists of covering a hot pattern with partially cured resin coated sand. Curing of the resin is completed and the cured sand shell is removed from the metal pattern, which is typically at a temperature of 450-600F. The process was refined and today major end-use industries for shell castings include motor vehicles, values and fittings, farm and construction machinery along with refrigeration and pumps. Dimensional control exceeds greensand-produced castings. Surface finishes often are 140-350 micro-inches or less. A number of sketches and photographs are shown in the article, including the design for the scroll air conditioning compressor.

Keywords:Designing, Shell casting, Fine detail, Tolerances.