Class 105 Polyvinyl Acetal Insulated Square Copper Magnet Wire is a type of magnet wire that is insulated with a layer of polyvinyl acetal material. Temperature degree 105°C, making it suitable for applications that require resistance to heat and certain chemicals.
Insulating Material
The coating is based on a blend of polyvinyl acetal and phenolic resins.
NOTE—Polyvinyl acetal in this case refers to the condensation product of polyvinyl alcohol and an aldehyde and includes polyvinyl formal (Formvar).
Table 1 Dimensions
| Insulation materials | Polyvinyl Acetal |
| Thermal Class | 105, indicating the wire’s maximum operating temperature. |
| Bare Wire Dimensions | awg 1 – awg 14 |
| Certificate | UL |
| Standard | MW-18-C |
Manufacturing Process Features
Formvar enamel / Polyvinyl Acetal is divided into large wire enamel and small wire enamel.
The large wire enamel has a higher viscosity, suitable for vertical machines with mold coating methods; the small wire enamel has a lower viscosity, suitable for horizontal enameling machines with felt coating methods.
The mold coating method has many advantages, such as stable varnish layer thickness, smooth surface, and high yield of qualified products.
Table 2 Properties
| Adherence and flexibility | No cracks visible in the film coating |
| Minimum Percent Elongation | MW Specification:18, 20, 36, 38, 64, 84T ≥ 0.049: 32T < 0.049:30 |
| Heat shock | No cracks visible in the film coating after 30% elongation followed by conditioning at 150 ±3°C. |
| Springback | Not greater than 5° |
Table 3 Periodic conformance tests
| Solubility | Specimens immersed in xylene shall not soften sufficiently to expose the bare conductor |
| Dielectric breakdown rated temperature | Average not less than 75% of the value required at room temperature, when tested on MW 15-C Heavy Build |
| Toluene / ethanol compatibility | No swelling or blistering in the film coating |
| Transformer oil resistance | No swelling or blistering in the film coatinga) Dielectric breakdown values shall average not less than the values in Table 4a) At least three of the five flexibility specimens shall show no cracks visible in the film coatinga) Elongation specimens shall show no swelling or blistering in the filmcoating |
| Thermoplastic flow | Median not less than 180ºC, when tested as MW 15-C Heavy Build |
Table 4 Dielectric Breakdown, Film-Insulated Rectangular and Square Magnet Wire
| Film Insulation | Minimum Breakdown Voltage | |
| Any Three of Four Values | Fourth Value | |
| Heavy | 1500 | 500 |
| Quad | 2500 | 900 |