Electrical resistance heating INDEX

Fiber Length (mm) Diameter (pm) Fineness (denier) Cell length (mm) Cell diameter (pm) Density (g/cm ) Specific heat (cal/g/ C) Porosity (%) Coefficient of friction Refractive index Electrical resistance (logR 10% moisture) (a kg/m ) Shape... 

The most important testing protocol for resistance to deterioration of critical physical properties upon exposure to heat, especially over prolonged periods of time, was designed by the Underwriters Laboratories (UL) [1], The UL temperature index is used to qualify materials for applications (such as use in electrical equipment) regulated by UL. The main purpose of these tests is to ensure that a polymer can be used safely for a prolonged period of time in these applications. A larger value of the UL temperature index implies greater stability, defined in... 

The relative thermal index is an indicator of a material s long-term resistance to degradation of its electrical, tensile, and impact properties at operating heats. This index is based on tests made to determine the half-life of these properties at elevated heat (i.e., the heat at which the plastic will retain at least one-half of its original properties for the projected life of an electrical appliance or product, up to 100,000 hours), such as summarized in Fig. 10-2. 

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