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TECHNOLOGY UPDATE: FINISHING
Coating attacks bacteria and fungus.
Porcelain enamels are used in a variety of applications were microorganism growth can lead to problems ranging from undesired aesthetics and foul odors to health issues. Porcelain enamels are commonly used on sanitary ware surfaces such as bathtubs and sinks. They are also used as coatings in appliances such as stovetop ranges and water heaters. It is possible to design a porcelain enamel coating that is anti-microbial.
An anti-microbial porcelain enamel can be defined as a porcelain enamel coating with a special addition to its composition that makes its surface more resistant to the buildup of bacteria, fungus, and mold. Historically, copper and silver have exhibited anti-microbial properties. Anti-microbial applications outside the field of enamels include carpets, fibers, towels, bedding, vinyl siding, sponges, medical equipment, paint, food, clothes, and packaging. Work has been done in the field of ceramic glazes for vitreous body tile and sanitary ware. Japanese patent publication 08333135 describes a sintered and crushed mixture of silver phosphate and kaolinite silicate, which is said to impart antibacterial properties to the glaze. Japanese patent publication 8100274 mentions a glaze containing borosilicate glass and/or a salt or chromium salt that is coated and baked on the surface of baked enamel. There have been many successful instances of fabricating ceramic tile with antimicrobial glazes. Manufacturers who produce vitreous china plumbing fixtures have had significant difficulties in achieving uniform anti-microbial protection over the entire piece. This can be attributed to the complex shapes, application techniques, long firing cycles, and heatwork...