Alpha-hemihydrate gypsum plaster

Alpha-hemihydrate gypsum plaster (autoclave gypsum)... 

Alpha-hemihydrate gypsum plaster has a distinctly lower water requirement than plaster of Paris and—at an equal consistency of the starting mix—exhibits a distinctly higher final strength. It is used in applications in which a high strength of the hardened material is essential, as in medical and dental applications, and in the production of molds for the ceramic industry. 

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