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Based on the
requirements, the best insulating material for the application will be
selected. The selection may involve examination of many different
performance properties. The properties are addressed in the following
sections and tables.
General Terms:
Thermoplastic:
Materials that soften and flow when heated. Usually possess a definite
melting point. The material will become firm again upon cooling. These
materials can be molded and shaped with a heating and cooling process.
(This process can be repeated.) Extrusion of melt flow polymers on wire
is an example of this type of material.
Thermoset:
Materials are soft and pliable during one stage of processing, can be
molded and extruded at this state after which they are set or cured,
usually at a higher temperature. After the setting process (cross
linking) is complete they cannot be softened by reheating, hence heat
and solvent resistance properties are improved over thermoplastic
materials.
Insulation:
Materials possessing good dielectric properties used on wire components
in cable usually as direct covering on conductors.
Jacket:
Materials that provide a protection in mechanical and chemical
properties applied as a direct covering over cable components. The
choice of materials for cable design to satisfy any given combination of
installation and environmental conditions can often be more critical
than the electrical requirements.
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