Heat-shrinkable plastics

The polymers used for heat-shrinkable products are usually 

Production sequence for heat-shrinkable materials is as follows. 

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This study is concerned with the application of heat-shrinkable plastics tubing and mouldings as terminations for medium-and high-voltage power cables in replacement of traditional cable termination systems. The first installations were at low voltages (240-440 V) in weather-protected... 

This study is particularly concerned with the application of heat-shrinkable plastics materials to power-cable terminations. Some of the principle types of cable involved are briefly described below. 

HEAT-SHRINKABLE PLASTICS IN HIGH-VOLTAGE (HV) APPLICATIONS... 

Clabburn R.J.T. and Penneck R.J., Heat Shrinkable Plastics for Power Cables, Insulation Engineer, July 1971. 

Heat shrinkable plastics, 305, 306 in high-voltage application, 310 High impact polystyrene, 5, 111 High speed train cab, 184-95 constructional details, 187 design considerations, 184-91 foam cores, 192 impact resistance, 186 materials, 191 material selection, 186 moulds, 192... 

PVC, PVA, PVAC, Copolymers) organosols forms available including hard and flexible types. Properties are highly dependent on plasticizer used. May be injection, extrusion, compression molded, vacuum formed. Low cost. antistatic sheet and hose, RF gaskets, heat-shrinkable tubing. 

ICT machines produced recently have energy ratings from 0.3 to 3.0 MeV and beam power capabilities up to 100 kW. Nearly 180 of these machines, the majority of them rated for less than 1 MeV, have been installed as of the early 1990s. They are used mainly for cross-linking of heat-shrinkable film, plastic tubing, and electric wire. ... 

Heat-shrinkable tubing is made typically from polyolefins, PVC, polyvinyl fluoride, PTFE, their blends, or blends with other plastics and elastomers. The formulations may be designed for chemical resistance, heat resistance, flame resistance, etc. ... 

Hot blown plastic films usually do not possess sufficient orientation to be heat shrinkable at temperatures below 100°C. For certain shrink packaging applications low temperature shrinkage is essential and can be obtained by biaxial orientation below the melting point. Radiation crosslinking was found to facilitate orientation of these copolymers greatly because of the much greater bubble stability which results from crosslinking. 

Irradiation of thermoplastics leads to cross-linking and thus imparts the properties of a thermosetting plastic. Tubing which has been expanded after the radiation treatment has a memory of its former size and will shrink to its original size when heated. Shrinkable tubing is available in a number of different plastics.2... 

Cell morphology of foamed PVC depends on concentration of a plasticizer, surface treatment of filler and foaming time and temperature. High concentrations of plasticizers produced poly disperse cell structure. Polyester plasticizer blends are useful for production of heat-shrinkable film. Plasticizer migration from geomembranes causes membrane shrinkage. ... 

The effect of radiation on materials has importance in the areas of wire and cable insulation, heat-shrinkable articles, curing of elastomers, plastics, paints and inks, electron beam lithography, medical sterilization, polymer property control, and outer space applications. 

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