Mould release and lubricating coating - contg. tungsten disulphide, silicate and setting agent esp for glass moulding

摘要

A lubricating and release coating is formed on surfaces of moulds and related parts by applying an aq. dispersion of a mixt. of (a) 30-70 wt.% WS2 having a lamellar hexagonal crystal structure and an average particle size 2 mu, (b) 15-25% silicate of Na, K, Li, guanidine, tetramethylammonium, tetraethanolammonium and mixtures, (c) 1-10 % setting agent from ZnO, CaCl2, MgSO4, Al2(SO4)3, Na borate, Na metaborate, Na fluorislicate, kaolinitic clays and minerals and mixts., to the surface and heating the moulds and parts to fix a thin coating of the silicate to th surface. The compsn. is esp. useful for coating glass-making moulds. A bottle mould coated with the compsn. produced 15,000 bottles and performed satisfactorily for at least 24 hours without further lubrication. When swabbed with conventional lubricant at 45-60 min. intervals, over 45,000 bottles were produced in 72 hrs., while uncoated moulds requires swabbing every 7-10 mins. and cleaning after 30 hrs.