GB1414461A - Electrical insulation sleeving - Google Patents

Abstract

1414461 Heat shrinkable insulating sleeve LAMINA DIELECTRICS Ltd 19 April 1973 [27 Jan 1972] 3929/72 Heading F2 [Also in Division H2] An insulating sleeving comprises an inner tubular structure which is adhesively secured to an outer tubular structure, the inner tubular structure consisting of a helically wound thin film preformed from a thermoplastic resin adhesive, and the outer tubular structure comprising a layer of a helically wound strip of heatshrinkable plastics material wound offset relative to the thin film. In the embodiment shown the inner structure is formed of a helically wound strip 1 with abutting edges and the outer structure comprises two helically wound strips 3, 4 also with abutting edges, the respective joints of each strip being non- coincident. The outer layer or layers strip can alternatively be wider than the inner layer strip and have an overlapping edge joint. The resin adhesive film can be of a polyester or ethylene vinyl acetate and have a thickness in the range of from 0À004 to 0À008 inch and the heat-shrinkable material may be a polyester, an ethylene vinyl acetate or a polyethylene terephthalate and have a thickness in the range of 0À0005 to 0À0025 inch. The outer strip or strips may also have a coating of a resinous adhesive on one surface thereof. The sleeve may be used for protecting and moisture proofing electrical joints or for encapsulating small electrical devices and may also be used for sealing the ends of small pipes by pinching and heat sealing and shrinking an end of the sleeve so as to form a sealed end cap (Fig. 5, not shown).