Abstract: A wrap-around heat-recoverable sleeve (1) suitable for providing environmental protection around pipes or cables (24) has self-contained electrical heating means powered through closure members (2,3) of the sleeve.

Abstract: Heat-recoverable articles, especially heat-shrinkable tubular articles, having an open end are formed so that the section adjacent said open end has a lower recovery ratio than a section adjacent thereto, thereby substantially reducing the risk of splitting when the degree of recovery is high or in applications where a high degree of unrecovered strain remains after recovery about a substrate such as a supply line. A preferred article is a tubular cap which has an open end section having a first expansion ratio, an intermediate section having a second expansion ratio and a closed end section having a third expansion ratio, the second expansion ratio being greater than the first and third expansion ratios. Such a cap may be employed to seal a conduit against ingress of moisture and other contaminants. When a supply line is subsequently to be passed through the conduit the closed end may be removed and the article shrunk to grip the supply line.

Abstract: A thermochromic composition suitable for coating heat-recoverable materials for cable enclosures. The composition contains an organic material which melts and decomposes at a certain temperature by trapping the decomposition products in the composition.

Abstract: Heat-recoverable articles carrying a "thermochromic" composition comprising organic materials which melt and decompose to provide a color-change indicating that the articles have been heated to a certain temperature, e.g. to melt a sealant carried on the surface of the article which is to contact a substrate around which the article is to be shrunk. Mixtures of relatively simple compounds may be used to graduate the color change, and means are described for preventing reversion to the original color on long-term exposure to moisture.