Magnet wire insulation

Polyvinyl Aldehyde 1940 H VG VG VG VG Most molding pro-cesses Used for coatings and magnet wire insulation, interlayer of safety glasses... 

Applications. PVF resins are used almost exclusively to make electric and magnetic wire insulation. In these applications the PVF resin component helps provide toughness, as well as abrasion and thermal resistance. 

Dual Constructions. In addition to the "basic" magnet wire insulations in which the conductor wire is coated with a single enamel, there are a number of cases where two different enamels are used one overcoated over the other. Examples include polyurethane-base insulation overcoated with poly(vinyl butyral) or with nylon, or polyester-base insulation overcoated with nylon or with polyamide imide. 

Trends in Magnet Wire Insulation. As long as energy and materials were inexpensive, the traditional magnet wire enameling method, which dates back to the 1920s, was an acceptable and widely used industrial process. 

Polyvinyl formal (PVF) is used to manufacture magnetic wire insulation as well as metal coatings and can linings. The quantities of PVF used are small and thus is a minor use for VAM. 

Table 10.8 shows electric strengths. Table 10.9 shows volume resistivities, Table 10.10 shows dielectric constants, and Table 10.11 shows dissipation factors for coatings using most of the available resins. Magnet wire insulation is an important use for organic coatings. National Electrical Manufacturer s Association (NEMA) standards and manufacturers trade names for various wire enamels are shown in Table 10.12. This information can be used to guide the selection of coatings. However, it is important to remember the aforementioned warnings about blends of various resins and the effects on performance properties.

NEMA also has developed standards and specified test methods for magnet wire insulation coatings. A summary of these materials, properties, and standards may be found in Appendix C. 

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