On an enameled wire in normal operation, most of the operator's energy and physical strength are consumed in the pay-off part. The replacement of the pay-off reel makes the operator pay a lot of labor, and the joints are prone to quality problems and operational failures when changing the line. An effective method is to pay off with a large capacity. The key to pay-off is to control the tension. When the tension is large, it will not only draw the conductor thin and make the surface of the wire lose its brightness, but also affect the performance of the enameled wire. From the appearance point of view, the enameled wire that is drawn thinner has poor gloss; from the performance point of view, the elongation, resilience, flexibility, and thermal shock of the enameled wire are all affected. If the pay-off tension is too small, the line will easily jump and cause the line to merge and the line to touch the furnace mouth. When paying off, the most fear is that the half-turn tension is high and the half-turn tension is small. This will not only cause the wires to loosen, break, and be thinned one by one but also cause large jumps of the wires in the oven, resulting in failures of merging and touching the wires. Pay-off tension should be even and appropriate. Installing a booster wheel in front of the annealing furnace is very helpful for tension control. The maximum non-extension tension of soft copper wire at room temperature is about 15kg/mm2, the maximum non-extension tension at 400℃ is about 7kg/mm2; the maximum non-extension tension at 460℃ is 4kg/mm2; the maximum non-extension tension at 500℃ The extension tension is 2kg/mm2. In the normal coating process of enameled wire, the tension of the enameled wire is significantly less than the non-extended tension, which is required to be controlled at about 50%, and the pay-off tension is controlled at about 20% of the non-extended tension.
Large-size and large-capacity spools generally use radial rotary pay-off; medium-size wires generally use over-end or brush-type pay-off; fine-size wires generally use brush-type or double-taper-type pay-off.
Regardless of the wire pay-off method, there are strict requirements on the structure and quality of the bare copper wire spool
The surface should be smooth to ensure that the wire is not scratched
There are 2-4mm radius r angles on both sides of the shaft core and inside and outside of the side plate to ensure balanced release during the pay-off process
After the spool is processed, a dynamic and static balance test must be performed
The diameter of the shaft core is required for the brush pay-off: the diameter of the side plate is less than 1:1.7; the over-end pay-off requirement is less than 1:1.9, otherwise, the line will be broken when the line is paid to the shaft core.