Enameled round copper wire
Enameled round copper wire
refers to the electromagnetic wire coated with lacquer as an insulating layer on the bare copper bare wire. It is widely used in electrical equipment such as transformers, motors, generators, refrigeration compressors, electric motors, household appliances and so on. Our enameled round copper wire
insulation is made of polyurethane or polyimide, which has excellent heat resistance and excellent solvent and refrigerant resistance.
Diameter Range (mm): 0.025-4.5mm;AWG:5-22
Heat resistance rating (℃): 130, 155, 180, 200, 220
Standard: IEC, NEMA, GB, JIS
Color: natural color, red, blue, green
Package: PT-4 PT-10 PT-25 PT-30 PT-60 PT-90 PT-200,wooden bobbin and according to customer requirements.
Breakdown voltage: 2500/5000V
Resistivity: 0.017241/0.02785 Ω mm2/m
Polyimide is the highest heat-resistant enameled wire lacquer in enameled copper wire
. Its heat-resistant temperature can reach above 220 °C, and it can work continuously at 220 °C. It has excellent performance in high temperature resistance, cold resistance, refrigerant resistance, chemical resistance and radiation resistance.
The production process of the enameled copper wire is: paying line → annealing → painting → baking → cooling → lubrication → take-up.
Annealing of copper wire is commonly used in three ways: disk annealing; continuous annealing on a wire drawing machine; continuous annealing on an enamel machine. The first two methods cannot meet the requirements of the enamelling process. The plate annealing can only soften the copper wire, and the oil removal is not thorough. Since the wire is soft after annealing, the bending is increased when the wire is released. Continuous annealing on the wire drawing machine, although the softening of the copper wire and the removal of surface grease can be achieved, the soft copper wire after annealing is wound onto the wire reel to form a lot of bending. Continuous annealing before painting on the enamelling machine not only achieves the purpose of softening and degreasing, but also the annealed wire is straight and directly enters the painting device, which can be coated with a uniform paint film.
The temperature of the annealing furnace is determined according to the length of the annealing furnace, the copper wire specification, and the line speed. At the same temperature and speed, the longer the annealing furnace, the more complete the recovery of the conductor lattice. When the annealing temperature is low, the higher the furnace temperature, the better the elongation, but the opposite phenomenon occurs when the annealing temperature is high. The higher the temperature, the smaller the elongation, and the surface of the wire is tarnished and even brittle.
The temperature of the annealing furnace is too high, which not only affects the service life of the furnace, but also facilitates the burning of the wire when the wire is arranged and broken. The maximum temperature of the annealing furnace is required to be controlled at around 500 °C. It is effective to use a two-stage temperature control mode for the furnace to select the temperature control point at a position where the static and dynamic temperatures are approximated.
Copper is easily oxidized at high temperature, copper oxide is very loose, the paint film can not be firmly attached to the copper wire, copper oxide has a catalytic effect on the aging of the paint film, and has adverse effects on the flexibility, thermal shock and heat aging of the enameled round copper wire
. If the copper wire is not oxidized, the copper wire at a high temperature is not in contact with the oxygen in the air, so there is a protective gas. Most of the annealing furnaces have a water seal and the other end is open. The water in the annealing furnace sink has three functions: closing the furnace mouth, cooling the wire, and generating steam as a shielding gas.
The water quality in the annealing tank is very important. Impurities in the water can make the wire unclean and affect the painting, and it will not form a smooth paint film. The chlorine content in the water used should be less than 5 mg/l and the conductivity should be less than 50 μΩ/cm. The presence of chloride ions on the surface of the copper wire corrodes the copper wire and the paint film over a period of time, creating black spots on the surface of the enameled round copper wire
within the enamelled paint film. The sink must be cleaned regularly to ensure quality.
The water temperature in the sink is also required. The high water temperature is conducive to the occurrence of water vapor to protect the copper wire in the annealing, and the wire leaving the water tank is not easy to bring water, but it is unfavorable for the cooling of the wire. Although the water temperature is low, although it has a cooling effect, the wire has a large amount of water, which is unfavorable for painting. Usually, the thick line water temperature is lower and the fine line water temperature is higher. When the copper wire has a sound that causes water to vaporize when it leaves the water surface, the water temperature is too high. Generally, the thick line is controlled at 50~60°C, the center line is controlled at 60~70°C, and the thin line is controlled at 70~80°C. Due to the high speed and the serious problem of water, the hot line should be dried by hot air.