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Electrical Coating & Insulating Varnish

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ELECTRICAL INSULATION COATINGS

There are 2 types of insulation coating namely primary & secondary insulation

Primary Insulation coating

Electrical devices such as motors, generators, and transformers function based on electromagnetic induction. The rotational or linear movement of such electrical rotary equipment is caused by electromagnetic fields, generated by electrical coils, and their mutual repulsion forces. The wire enamel is applied to the metal wire concentrically in several coating operations in a thermal coating process, so-called enamelling process. The wire enamel is a varnish and consists of organic components (prepolymers) that react to cross-linked polymers during the baking and thus form an impermeable insulation layer or electrical coating.

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Secondary Insulation

The best stability under all operating conditions is achieved by electrical rotary equipment (motors and generators) and static electrical equipment (transformers and sensors) if all the air trapped inside the wire windings is replaced with insulation material. This stage of the value-added chain is known as impregnation or secondary insulation. This commonly thermal impregnating process, i.e. chemical process under the action of heat, also increases the mechanical stability of the electrical winding and protects the enamelled wire during operation from environmental influences such as moisture. This impregnation can entail a trickling of the wire winding, a dip or dip-and-roll process. Today impregnation is increasingly carried out through the vacuum method to eliminate any air that might be trapped (VPI process). Trapped air bubbles reduce heat dissipation, since air is an excellent heat insulator, or they give rise to disruptive electrical charges in high-voltage applications, which can destroy the insulation. Besides, UV light curing might be employed, which creates very highly cross-linked, and thus impermeable, impregnating layers. The impregnating resin or varnish (impregnating material generally) consists of organic components (prepolymers) that react to cross-linked polymers during the curing process and thus form a further electrical insulation layer added to the wire enamel.

The following different impregnating resins exist

Unsaturated polyester resins (UPs) with styrene or vinyl toluene as a reactive thinner UP without volatile organic substances (Monomer free so-called MF resins) Epoxy resins Water-based adhesives Alkyd resins with an organic solvent or water-based. Where transformers for electrical power transmission are concerned, by impregnating resins (dry transformers), or insulation fluids (wet transformers) are used.

PCB Fixations

Recommendation

Depending upon various factors like Customer Specified Coating Requirements, Budgets, Quality of Pre Surface Treatment, Availability of Paint Shop, Skilled Painters and many others… We Recommend below Three Coating Systems for Optimum and Most Effective Results.

  • Polyurethane & EPOXY Based Weather Resistance and Corrosion Protection Coating System
  • High Solid PU & Epoxy Zinc Rich/ MIO based High Protective Coating System
  • Fast Cured Synthetic Enamel based Conventional Coating System

List & Variety Of Items We Manufacture For Electronics & Insulation Industry

SR ITEM NAME AREA OF APPLICATION
1 Stoving Varinsh for insulation Primary Insulation
2 AD Alk-Ph Gold Varnish Primary Insulation
3 Insulating Varnish Red Primary Insulation
4 Oil Resistance Coating for Oil Tanks internal Lining Primary Insulation
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