Grinding, paint manufacturing

Available Forms. Phthalocyanines are available as powders, in paste, or Hquid forms. They can be dispersed in various media suitable for aqueous, nonaqueous, or multipurpose systems, eg, polyethylene, polyamide, or nitrocellulose. Inert materials like clay, barium sulfate, calcium carbonates, or aluminum hydrate are the most common soHd extenders. Predispersed concentrates of the pigments, like flushes, are interesting for manufacturers of paints and inks (156), who do not own grinding or dispersing equipment. Pigment—water pastes, ie, presscakes, containing 50—75% weight of water, are also available. 

Colloid mills are used to grind and disperse solids in hquids and to prepare emulsions. They operate on the principle of high-speed fluid shear to grind the feed material. Another application is in the manufacture of lubricating greases by dispersion of calcium stearate in hydrocarbon oils. In the paint industry, colloid mills are used to incorporate pigments in liquid vehicles. In the food industry, the mills are used to make purees, sauces, ointments, creams, lotions, and other products. 

Surface Preparation The steel surfaces to receive the membrane lining must be smooth, free from pits, millscale, weld splatter, and lap welds. Corners must be rounded to an internal and external radius of % inch minimum. The surface must be sandblasted just before application of the membrane on interior surfaces and a paint system on exterior surfaces. Sandblasting should be in accordance with specifications supplied by the manufacturers of the membrane and protective coating system. This may require welding inside corners and then grinding to the proper radius. 

Pebble mill n. A rotating porcelain, buhr-stone (or other non-metallic lined) cylinder containing pebbles or porcelain balls or rods as the grinding media. In the manufacture of pigments or paints it is used to grind and/or disperse. 

Furfuryl alcohol is used as a viscosity reducer for epoxy formulations. The addition of furfuryl alcohol to urea-formaldehyde resins improves the craze resistance and heat stability of the adhesives. Furfuryl alcohol serves as an effective wetting agent and solvent for phenolic resins in the manufacture of phenolic resin abrasive grinding wheels. Other miscellaneous uses of furfuryl alcohol include use in alkaline paint strippers and cleaning formulations, as a solvent and carrier for dyes in textile printing, and as a chemical intermediate. 

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