GB1489237A - Covering method recoverable article and insert - Google Patents

Abstract

1489237 Coated substrates RAYCHEM CORP 11 June 1974 [11 June 1973] 25851/74 Heading B2E [Also in Divisions B5 and H2] A substrate is covered with an insert and a recoverable member the insert comprising a corrugated "fusible material" or a "fusible member" having at least one protruberance, the recoverable member is recovered to cause the protruberances or corrugations to be detectable through the recoverable member and heat is applied to the fusible material or member to cause it to "flow". The recoverable member may be a sleeve, sheet or T, Y or X piece and is preferably heat shrinkable or expansible. It may be made of polyethylene, polypropylene, polyurethane, PVC, PTFE, a polyamide or polyvinylidene fluoride. The insert may be a coating on the inside or outside of the recoverable member. It may be made of solder, hot melt adhesive, polyethylene, polypropylene, a polyamide, polyethylene terephthalate, an epoxy resin, a polyurethane, a phenol-formaldehyde resin or a polyether sulphone. The protruberances may be on one or both sides of the insert and may be the same material as the insert or of a different material and may have a higher or lower melting point than the fusible insert. If of a lower melting point than the insert is used in a process where after the disappearance of the protruberances, heating is continued for a set time thereby to ensure melting of the insert. The protuberances may be disposed towards or away from the substrate and may be infusible e.g. particles of metal, ceramic or thermoplastics material, or hollow so that foaming agents in the liner produce a foam that occupies the space originally taken by the protuberances. They may be formed as bumps or continuous or discontinuous ridges over the entire insert or parts thereof, by extrusion, embossing, engraving (Figure 7 not shown) or coating e.g. using a spray head to give a helical ridge (Figure 8 not shown). Identical or differently shaped ridges and bumps may be formed over the insert. The "fusible member" comprises a "fusible material" which is defined as not only embracing those materials which show a sharp drop in viscosity at a particular temperature but also materials which are not strictly fusible but do become less viscous on heating e.g. initially flowable thermosetting materials such as epoxy resins, polyurethane resins and phenol-formaldehyde resins. A material is said to "flow" or to be flowable if it has substantially no stability of form under pressure exerted on it by the recoverable member.