Formvar enamel is made from vinyl acetal resins produced as a smooth uniform film. Formvar has excellent mechanical properties such as abrasion resistance and flexibility. The film will withstand excessive elongation without rupture. When stressed during winding, Formvar has a tendency to craze upon contact with solvents such as toluene, naphtha, xylol, etc. Formvar can be removed mechanically or chemically during terminal preparation.
Typical applications are within motors, random and precision wound coils, oil filled and dry transformers, armature and generator winding where "tough" film may be required.
Electrical properties
| Property | NEMA MW-1000 | ASTM D1696 | IEC 851 | JIS C 3003 | MW-15-C |
|---|---|---|---|---|---|
| Dielectric strength at 25°C (77°F) | 3.8.1.1 | 69-75 | 13-4.2, 3, 4 | 11.1 | 13.1 kV |
| Dissipation factor at 220°C (428°F) | 107-114 | 0.05 |
Mechanical properties
| Property | NEMA MW-1000 | ASTM D1696 | IEC 851 | JIS C 3003 | MW-15-C |
|---|---|---|---|---|---|
| Adherence and flexibility no snap 20% snap |
3.3.1.1 3.3.1.1 |
141-148 141-148 |
8-5.1.1 |
8.1 9.1 |
Pass 1d Pass 1d |
| % elongation at break | 3.4.1.1 | 122-129 | 6-3.0 | 36 | |
| Mandrel at break | 3.4.1.1 | 122-129 | Pass 1d | ||
| Cut-through temperature | 3.50.1.1 | 61.68 | 261°C (502°F) | ||
| Heat shock 20% stretch - ½ h at 200°C (392°F) |
3.5.1.1 |
156-162 |
9-3.1 |
14.1 |
Pass 3d |
Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Alleima materials.