Technical Know how Producing Alpha Plaster

In the dental trade, plasters are used in the making of impressions for dentures, in lay and for the casting of metal filling, bridges, etc. Art moulding includes the making of a great variety of art objects and novelties formed by the casting of gold, silver and other non- ferrous metals in plaster of Paris investment moulds. Plaster of Paris also finds a considerable industrial potential in the forming of non-ferrous metal objects and mechanical parts by plaster of Paris investment moulds. Plaster of Paris is also required by artisans and for temporary structure construction used in the film industry.

The product is being produced by number of firms but the demand of the product is ever increasing since it has versatile application and is used all over the country and as well as abroad. Therefore, the process offers a very good prospect for entrepreneur for local as well as export markets.

Alpha plaster can be used wherever low strength beta plaster is used. Because of its superior strength and subsequent increase of the life of the moulds, alpha plaster is preferred to beta plaster.

PROCESS

Or mineral gypsum is pulverised to 120 to 130 I.S. mesh. The pulverised gypsum is fed to reactor where water is added to make slurry, with addition of modifier. The reaction is carried out under pressure at 40 psi for 2 & 1/2  hour under agitation. The slurry is filtered hot, using vacuum filtration. The cake is washed with boiling hot water. The hot cake is transferred to dryer immediately in hot trays and dried at 120- 130⁰ C. The dried product is seived throught 150 I.S Mesh packed in laminated/ linner bags