Flame polishing

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Polishing of pressed glass ware

Polishing of pressed glass became as a standard for all quality pressed glass tableware. It replaced or at least reduced use of environmentally unfriendly acids for chemical polishing of lead crystal. Polishing of pressed glass is used generally for getting smooth, brilliant surface of goods with no sharp edges and for removing of visible marks after moulding, removing of orange peel, cold waves etc. . Besides of these „visible“ effects, flame polished surface is more resistant to chemical and mechanical load.

Flame polishing is done on carousel, line or on single position machines. Pressed glass pieces are slightly cooled down to about 300 - 400oC depending on many features like shape, size, wall thickness, glass type and glass surface quality.

Tepmerature of glass before polishing should be generally as high as possible but not so that (untitled)flame polishing destroys a product shape. Polishing can be done by flame with oxidising or with reduction character depending on type of glass and following treatment. That is an opportunity for Oxy-fuel with high temperature and efficient heat transfer from a flame directly to the glass surface.