Plaster substitute using reduced amt. of gypsum - comprising 50 per cent plaster, 50 per cent filler, and binder e.g. polyvinyl acetate or urea! formaldehyde

摘要

A construction material intended to economise on plaster in the construction industry of countries without gypsum deposits is prepd. from a mixt. contg. 50 wt. % of plaster and 50 wt. % of plaster and 50 wt. % of a finely divided material, to which is added 0.5 wt. % of a binding agent. The resulting prod. is intimately mixed with 30-35 wt. % water, for 3-5 mn. then poured into a mould. The mould is placed on a vibrating table to allow the air bubbles to rise to the surface before the material sets. The final construction material obtd. is then demoulded. This construction material has the qualities of plaster but costs less in countries without gypsum deposits. The finely divided material is e.g. sand, clay or sawdust. The binding agent contains e.g. polyvinyl acetate, strongly etherified methylhydroxethyl cellulose, urea-formaldehyde or critic acid.