Fibreglass Varnished Fabrics are normally used for application where operating temperature is class 'B' (130 °C) or above. Fibreglass Varnished cloth and tapes can be used for wide variety or electrical applications where material with high tensile strength and flexibility is required. Composition: A low alkali content 'E' glass fabric heat cleaned and treated with coupling agent is impregnated with glyptal type varnishes. The glass fabric imparts good mechanical properties while varnish possesses high dielectric strength. Materials are available in straight cut and bias cut form.

Insulation:
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Type 1: Varnished glass fabric is applied helically with successive layers coated with synthetic varnish. Glass fabric is woven from "E" glass yarn with alkali content not more than 1%, A braid of glass fibre varnished with synthetic varnish is given externally.
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Type 2: Varnished glass fabric is applied helically with successive layers coated with silicone varnish. A braid of glass fibre varnished with silicone varnish is given externally.