Sprayable insulating coating for workpieces - contains mineral fibres and alkali silicate binder, and suitable for coating large turbine casings

摘要

Parent patent described sprayable compsn. employed for the insulation of metallic- or nonmetallic-workpieces. The compsn. consisted of a binder soln. contg. 1-10 wt.% of alkali silicate(s), esp. 2-6%; plus mineral fibres contg. >15% kaolinite; and >=1 water-soluble and alkali-resistant organic polymers and/or fine silica. In this addn., the mineral fibres are not brought into contact with the binder soln. until they meet on the surface of the workpiece. Separate spraying nozzles are pref. used for the mineral fibres and the binder, esp. where an inner nozzle for the fibres is located inside a ring nozzle for the binder. No asbestos fibres harmful to human health are used in the compsn.; and insulating coatings of the required thickness are easily obtd. by using fibres and binder which do not meet until they impinge on the workpiece surface.