Patent ID: 6099905
Filing Date: 2000-08-08
Classification: C03C

Abstract:
A process for producing on the outer surface of a glass volume, including bottles or flasks, an indelible decoration consisting of particles of enamel each fused in situ with the surface layer of glass of said volume, which comprises:a) spraying onto said outer surface a slip containing a frit of enamel particles by a pneumatic gun, said frit having a melting point lower than the softening point of said glass and a coefficient of thermal expansion comparable to that of said glass, said slip comprising a suspension of liquid binder of oil and water with the frit suspended therein, said slip having a viscosity on the of 4.5 to 5 minutes evaluated by the Ford Cup method, which is sufficiently viscous such that said frit remains temporarily in place on said surface;b) firing said frit by heat treatment at a temperature sufficient to melt said frit particles on said surface while fusing with it, while preserving the individuality of the particles,whereby there is created on said outer surface to be decorated a discontinuous visual or tactile impression of a patina or layer of dust.