Compression moulded phosphate plaster articles - made by mixing dehydrated phosphate plaster with water and moulding under pressure

摘要

Plaster articles are made by (a) forming a mixt. of 18-25 wt.% water and phosphorus plaster (I) which has been dehydrated in the same way as natural plaster, and (b) introducing the mixt. into a suitable mould and hardening under pressurE, ot. in the presence of additives to accelerate the cure and/or to reduce the wt. of the moulded article. The process allows moulding of (I) without special purificn. treatments to remove impurities which retard hardening, which is normally required with phosphate plasters.