Heat-shrinkable product

Electron beam-initiated modification of polymers is a relatively new technique with certain advantages over conventional processes. Absence of catalyst residue, complete control of the temperature, a solvent-free system, and a source of an enormous amount of radicals and ions are some of the reasons why this technique has gained commercial importance in recent years. The modification of polyethylene (PE) for heat-shrinkable products using this technique has been recently reported [30,31]. Such modification is expected to alter the surface properties of PE and lead to improved adhesion and dyeability. 

The radiation-treated cables find wide applications in control instmmentation of nuclear power reactors, particle accelerators, aviation, and telephone equipments. Usually PE and PVC are radiation cross-linked for production of such cables. The heat shrinkable foils are widely used in packaging, electrical and electronic industries. The radiation cross-linked PE possesses the property of elastic memory which is utilized to produce heat shrinkable products. 

The formation of carbon-carbon cross-links is by far the most important effect and is the basis of the applications in wire and cable industry and for heat-shrinkable products. The factors affecting the changes of polyethylene by irradiation are the molecular weight distribution, branching, degree of unsaturation, and morphology. °... 

Heat stability Heat stabilizers Heat-shrinkable products Heikens... 

Shrinkablefilm and tubing Cross linked semicrystalline thermoplastics display rubberlike properties at temperatures above their melting points. On deformation followed by fast cooling the polymer maintains its deformed shape. The polymer returns to its original shape when reheated. This memory effect is applied in the production of heat shrinkable films and tubing. Radiation doses of the order of 40 — 1(X) kGy are used in the production of heat shrinkable products. 

The polymers used for heat-shrinkable products are usually... 

Electron Beam Process in the Production of Heat-Shrinkable Materials... 

Production and application of heat-shrinkable tubing on a wire splice. (Radiation Processing of Polymers (Singh, A., and Silverman, Eds.) Carl Hanser Publishers, p. 20 (1992). With permission from Carl Hanser Publishers.)... 

The use of radiation to modify the physical properties of polymers has become a very important industry with products such as electrical cables with insulation capable of withstanding high temperatures and heat-shrinkable polyethylene. However, of direct relevance to this symposium was the recognition in the early 1970 s that electron beam irradiation of pol3mier films could provide an important lithographic tool for the manufacture of microelectronic components. For consideration of the general principles of these processes see, for example, references (66) and (67). The products required In this field are complex requiring both microscopic... 

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