Polyvinyl acetal round enameled copper wire is an electromagnetic wire with polyvinyl acetal resin (such as formal PVF or acetal) as the insulation coating. It has unique oil resistance and mechanical properties and is widely used in electrical equipment.
Resin composition and structure: The insulating layer is made of polyvinyl acetal (PVF or PVB) and phenolic resin to form a dense polymer coating with flexibility and high dielectric strength (up to 45kV/mm).
The molecular chain of acetal resin contains ether bonds and hydroxyl groups, which give the paint film excellent adhesion (0-2 levels in the Baige test) and wear resistance, suitable for high-speed winding process.
Temperature resistance: The temperature resistance grade is E (105-120℃), the long-term working temperature range is -40℃ to 120℃, and the heat shock resistance is strong (passed the 150℃/168h aging test), but the thermal softening breakdown temperature is low
Mechanical properties: The paint film has good elasticity, tensile strength of more than 300MPa, and can withstand repeated bending of 1d-3d radius (winding test).
There are two processes: large line paint and small line paint: large line paint has high viscosity and is suitable for mold coating (vertical machine); fine line paint has low viscosity and adopts felt method (horizontal machine)
Application fields
1. Transformers and motors
Oil-immersed transformers: Taking advantage of its oil resistance and hydrolysis resistance, flat wire models can also be used for transposition conductors of large transformers to reduce eddy current losses.
Motor windings: Such as AC motors and servo motors, due to their high mechanical strength, they can increase the slot fill rate (up to 85% or more) and power density.
2. Potential in emerging fields
In new energy vehicle drive motors, the multi-layer paint film structure can withstand a voltage of more than 2000V and meet the IP67 protection requirements.
Wire bonding of electronic devices (such as X-Wire technology), replacing gold wire to reduce costs.
Round enameled copper wire specifications：
| Name | Round enameled copper wire |
| Conductor | Copper |
| Dimension | 0.016mm-7mm |
| Thermal Class | 130(Class B),155(Class F),180(Class H),200(Class C).220(Class C) |
| Insulation Thickness: | single /heavy |
| Standard | IEC 60317-3 / GB/T 6109.3 / NEMA MW 28C |
| Certificate | UL |
| Packing | 30kg-150kg ply-wood spool(250*400 / 250*500/ 250*600/ 250*730) |