Coating and Glazing

The damaged surface of a ceramic after finishing is sometimes healed by coating. Coating methods include (1) sol—gel, (2) laser gazing, (3) chemical vapor deposition (CVD), (4) sputtering, (5) plasma spraying, 

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Fried Nuts Peanuts, cashews, sunflower seeds, pumpkin seeds, and so on are sold in various forms, such as fried, dry roasted, coated, and glazed. The fried nuts absorb very little oil from the fryer. This makes the oil turnover time in a fryer very long. Oils used in this process must have good oxidative stability in order to have good product shelf life. 

Because of the low glass transition, acrylic esters are free radically polymerized in emulsion and the emulsions produced are used directly as coating and glazing solutions, automobile lacquers, floor treatment materials, and as additives in the leather industry. 

The first description of sauerkraut manufacture, comparable to the methods used commercially today, was given by James Lind in 1772, in his treatise on scurvy. Barrels, kegs, and stone crocks were the common containers. Wooden vats were introduced in the United States about 1885. Recently, reinforced concrete with plastic coatings and glazed tile vats have been introduced. 

RTV silicones are used by the automotive, appliance, and aerospace industries for electronic potting compounds and formed-in-place gaskets, to form molds for the manufacture of plastic parts, and widely in construction adhesives, sealants, roof coatings, and glazing. 

Uses are as emulsifier in margarine, desserts and cakes. The main application is, however, in coatings and glazes and icings. Nonfood uses are in pharmaceuticals, ointments, lotions and shampoos. Almost 2000 mt were used in USA in 1981. 

Epoxy resins for printed circuits, castings, rocket motor casings, coatings, and adhesives are almost all made from bisphenol A. Polycarbonates based on bisphenol A are used in glazing applications such as aircraft windows, school windows, and other areas where a combination of toughness and high clarity are required. 

Boric oxide is used to produce many types of glass including low-sodium, continuous filaments for glass-belted tires, and fiberglass plastics. It also is used to make ceramic coatings, porcelain enamels and glazes. Also, the compound is used as an acid catalyst in organic synthesis and to prepare several other boron compounds. 

The oxidised waxes (containing various ratios of fatty acids, esters and alcohols) are used in the manufacture of various polishes, anti-corrosion coatings, tile glazing carriers, precision casting waxes, mould release agents, metal coatings etc. 

The uses of boric oxide relate to its behavior as a flux, an acid catalyst, or a chemical intermediate. The fluxing action of B203 is important in preparing many types of glass, glazes, frits, ceramic coatings, and porcelain enamels (qv). 

The bottom of a piece should not be coated with glaze. Coated bottoms, when heated, will melt and stick to the shelf of the kiln. (Kiln firing is discussed later in this chapter.)... 

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