AIRLESS SPRAY-COATING OF A SURFACE WITH A VISCOUS AQUEOUS ARCHITECTURAL COATING COMPOSITION

摘要

A PROCESS FOR THE AIRLESS SPRAY-COATING OF A SURFACE WITH A VISCOUS AQUEOUS NON-NEWTONIAN ARCHITECTURAL COATING COMPOSITION WHEREIN THE COMPOSITION CONTAINS A PREFERABLY ASSOCIATIVE THICKENER AND IS SUBJECTED TO A PRESSURE OF FROM 2.5 TO 5 BAR GENERATED PREFERABLY BY HAND-OPERATED COMPRESSOR AND THEN SPRAYED FROM A PREFERABLY SLOT-SHAPED OUTLET ORIFICE (52) IN A NOZZLE (50) TO PRODUCE AN OUTFLOW (31) OF COMPOSITION HAVING BOUNDARIES (35) WHICH DIVERGE AT LEAST UNTIL IT HAS FORMED A FRONT OF AT LEAST 30MM IN WIDTH. THE COMPOSITION PREFERABLY HAS A BROOKFIELD VISCOSITY OF AT LEAST 0.5 PA.SEC AND A SOLIDS CONTENT OF 7 WT%. ALSO APPARATUS FOR PERFORMING THE PROCESS COMPRISING A CONTAINER CONTAINING THE COATING COMPOSITION TOGETHER WITH A NOZZLE HAVING AN OUTLET ORIFICE, A HAND-OPERATED COMPRESSOR AND A PRESSURE RELEASE VALVE ACTUATABLE IN THE PRESSURE RANGE 2.5 TO 5 BAR PREFERABLY AN AUXILIARY ORIFICE UPSTREAM OF THE OUTLET ORIFICE. THE PROCESS AND APPARATUS ENABLE THE VISCOUS COMPOSITIONS TO BE APPLIED QUICKLY USING LOW PRESSURES EASILY GENERATED BY A HAND COMPRESSOR.