METHOD FOR THE SELECTIVE ETCHING OF THE SURFACE OF A GLASS ARTICLE

摘要

The process for selectively depolishing a surface of a glass article, comprises protecting a part of the surface, which is not to be depolished, by laying a protective layer so that the article surface is coated selectively, polishing the non-coated surface, and finishing the article surface by eliminating the protective layer. The protective layer is a coating of wax having low melting point. The depolishing of the surface is carried out mechanically by sandblasting under pressure. The protective layer is removed by projecting a hot solution on the article surface. The process for selectively depolishing a surface of a glass article, comprises protecting a part of the surface, which is not to be depolished, by laying a protective layer so that the article surface is coated selectively, polishing the non-coated surface, and finishing the article surface by eliminating the protective layer. The protective layer is a coating of wax having low melting point. The depolishing of the surface is carried out mechanically by sandblasting under pressure. The protective layer is removed by projecting a hot solution on the article surface. The surface area of the glass article is 5 m 2>. The selective deposition of the protective layer is carried out by serigraphy using a hot applicator and a distribution system comprising an inkjet head. The protection step provides three deviations of the inkjet head for a given point of the glass article surface. The inkjet head is positioned slightly different in each deviation to refill gaps present between wax coatings. The wax is a mixture of natural wax and/or synthetic wax in any proportion, and melts at 50-140[deg] C. The melted wax has a dynamic viscosity of 5-30 mPas at 100[deg] C. Grains of abrasive material having an average equivalent diameter of 0.05-1 mm are projected under pressure during the depolishing step using an automated sanding chamber equipped with a conveyor or a manual pistol. The sanding is carried out at a speed of 3.5-12 m/minute. The hot solution comprises aqueous detergent and/or an organic solvent. The natural wax is mineral wax obtained from petroleum such as paraffin and microcrystalline wax. An INDEPENDENT CLAIM is included for a glass article.