Abstract:
An improved process for coating an inert substrate, such as braided glass fiber sleeving and inert substrates of other materials and shapes, wiht a polymeric material such as a polyacrylate, a polyvinyl chloride, a silicone rubber, or a polyfluorocarbon, said method comprising the steps of: formulating an emulsion of the polymerizable material in water or other suitable polar phase; thickening the emulsion through the addition of an inert, finely-divided, particulate, hydrophilic inorganic oxide substance to a viscosity in the range of from about 35,000 to about 500,000 centipoises; applying the thicknened emulsion in the form of a uniform coating of desired thickness to the sleeving or other inert substrate; passing the coated substrate through a microwave energy chamber and subjecting the thickened emulsion coating to microwave energy of a frequency, at a power density, and for a peirod of time sufficient to substantially devolatilize, or dry and coalesce, said emulsion; and subjecting the devolatilized coating to thermal energy at a temperature and for a period of time sufficient to substantially complete polymerization. A braided glass fiber sleeve, or inert substrate of other configuration or material, containing a surface coating of a polymer, such as a polyacrylate, a polyvinyl chloride, a silicone rubber, or a fluoropolymer, such coating having substantially uniformly distributed therethrough very finely-divided particles of a chemically inert, hydrophilic, inorganic oxide, such as fumed silica, precipitated silica or aluminum oxide.