| 摘要 |
<p>1,180,704. Cooking vessels. NATIONAL PRESTO INDUSTRIES Inc. 26 July, 1968, No. 35895/68. Heading A4A. [Also in Division B2] A cooking vessel comprises a metallic base coated with a first layer comprising a mixture of polytetrafluoroethylene, finely divided non-spherical particles of metal and finely divided particles of a metal oxide, a metal carbide, or mixtures thereof, and then a second layer consisting essentially of P.T.F.E. The non-spherical particles of metal may have an average size of about 20-12 microns The first laver may he formed by first baking on to the metallic base, the mixture, and then baking on to the first layer the P.T.F.E. to form the second layer. The base which may be of, for example, aluminium, aluminium alloy, iron, steel, copper, brass, may be first cleaned by blasting with grit, sand or oxide, or etched. The non-spherical particles may be of aluminium, iron, steel, copper, brass, chromium or nickel. The oxide or carbide may be of aluminium, titanium, zirconium, silicon, chromium and nickel. The first layer may be formed by baking on the metallic base a mixture comprising 50-60 volumes of aluminium oxide powder, 50- 40 volumes of aluminium powder, the two together making up 100 volumes, and 100 volumes of polytetrafluoroethylene emulsion that contains 50 per cent by weight of solid polytetrafluoroethylene resin. The first layer may be about 1 mil and the second layer about 0.4 mil in thickness. The coating provides a surface portion which is characterized by a high degree of abrasion resistance, scratch resistance and resistance to sticking thereto of foods in contact therewith during cooking.</p> |
