Uses and production processes tinned flat copper wire
Tinned flat copper ore is mainly used for rubber insulated cables with outside, rolling stock cables and marine cables and other conductive core, and wire and cable shielding braid. After copper tin can effectively prevent oxidation and copper rubber in contact with the rubber caused by copper sticky, black copper and other issues, while increasing core cable life and weldability.
At present, China's production of tinned copper wire and cable industry, mainly chemical tin (tin plating) and physical tinning (hot tinning) in two ways. Tin plating is more advanced mode of production, its main advantage is that the coating thickness, and arbitrary control, but the process is relatively hot tin complex operation demanding higher equipment prices. Hot tinning process is simple, and low equipment prices, they have been used by many manufacturers. Since each plant is different hot tinning process, the quality of the production of tin-plated copper wire is also different. Based on years of production experience, we consider the following factors as a key to the quality tinned copper for reference purposes only.
2 Mass copper, tin
Tinned copper raw material is copper and tin. As I plant the production of tin-plated copper wire having a diameter of 0. 2 mm or less, and therefore relatively high demand for copper. This can effectively improve the copper plating process in a single line lengths, tinned copper wire breakage rate reduction. Some people think that, before the tin to copper pickling, so the strict quality requirements of copper. Notice severe surface oxidation or contamination of the copper cleaning purposes can not be achieved in a short time in the pickling process, so to produce the tinned copper tin layer and the copper-binding is not strong, easy to fall off, and the more pinholes. Because copper quality directly affects the quality tinned copper, therefore, it must be corrected for low-quality tinned copper wire with copper prejudices. I believe that quality tinned copper wire with copper should reach manufacturing enameled copper wire used in the technical requirements.
Tin quality directly affects the quality tinned copper wire. If you use low-purity tin ingot or market miscellaneous tin production had 程中锡 furnace temperature difficult to control, easily lead tin alloy layer of the finished line, affecting the continuity and adhesion of the tin layer. And because too many impurities, it is easy to plug the die orifice, resulting in frequent breakage, affect the finished single line length. Therefore, in order to ensure the quality tinned copper wire, tin ingots used should not be less than GB / T in tin II technical requirements 728-1984.
3 Production of several issues should be noted
Hot tinned fine copper production process is: actinomycetes → annealing → pickling → → cooling → Traction → tin take-seven processes, the process by which the following statements were technical points and considerations.
(1) actinomycetes. The production line is put in the key. Copper plating surface should be smooth with rounded, in line with national standards. Just pulled out of thin copper wires due to the surface lubricating fluid, easily oxidized copper surface should be tinned as soon as possible. The author recommends the use of take-φ160 reel (can be loaded copper 7 kg), and requires copper cable uniform, elastic should be moderate, rim should be smooth. Actinomycetes should adopt the more-ended (no release thread), which is relatively small because the diameter, put the line speed, the production process can easily break. After repeated tests, we used to put lines on the disc plus blankets to block the line, a good line to avoid touching rim. While increasing the height of the guide wheel between the disc and the discharge line discharge lines to increase the reliability of the discharge line, reducing the chance of breakage.
(2) annealing. Copper annealing temperature is a key factor affecting product line elongation. Because even into the reheating furnace, which is not too high annealing temperature (annealing temperature slightly below normal). For thin 0. 2 mm in diameter or less, it should be controlled at 300 ~ 330 ° C, so that elongation is slightly below the national standard.
(3) the pickling. Copper into the tin stove, be sure to use the appropriate acid lotion for cleaning, to ensure that the tin layer and copper have good adhesion. Pickling using a mixture of zinc chloride, ammonium chloride, ****** and water in a ratio of 1:5:10:100. To ensure clean, felt the pressure line should be used the way, felt a width of 20 cm, regular use of pickling pouring felt.
(4) tin stove. Tin furnace temperature on the quality of the product plays a key role. Furnace temperature is low, tinned copper surface rough, easy to break; furnace temperature is high, the tin-plated copper wire is prone to yellowing. After repeated tests, furnace temperature to 320 ° C is appropriate (due to the choice of a relatively low number of copper annealing temperature, solder pot temperature here intends to appropriately increase). The finished product line surface coating is smooth, continuous, elongation also reached the national standard.
Tin tin furnace when heated, surface oxidation soon, will result in waste. To prevent contact that can be covered in a layer of molten tin liquid surface of mica, charcoal powder, to keep out air and tin liquid surface.
Tin and copper combination is good or bad, in addition to the copper surface to be pickled, the purity of liquid tin itself also an important factor. Therefore, the liquid component of the tin should be tested once each half, in which the copper content shall not exceed 1%, such as more than 1% should be regenerated or replace tin. Specific method of regenerating the sulfur containing powder into a metal tube with holes, sinking into the bottom of the metal tube, until fully escape of sulfur dioxide so far. Such liquid contained in the copper-tin copper sulfide float will be, can be removed. The operation should note that the product was toxic.
(5) scraping tin mold. Currently scraping tin mold market mainly diamond mold and rubber mold. Diamonds scratch using tin mold, good surface quality tinned copper wire, but the price is high. For the production of thin tin-plated copper wire, because the faster, use rubber molding operation and control more difficult, likely to cause breakage, and each will be used to re-produce some copper as a towing line and not tinned produce ten meters Copper unnecessary waste. Diamond mold operate and simple to use good quality tinned copper surface, thus producing thin diamond die better. Production should pay attention to mold angular adjustment to ensure tin furnace pressure line fulcrum, scraping tin mold center and anchor guide wheel in a straight line.
Scraping tin mold aperture is a tinned copper key factors influencing the quality. Aperture is small, then break frequently. Pore size is too large, the partial thickness of the tin layer, affecting the quality of the coating, and the consumption of tin increased costs. After production tests and on the performance of the test, scraping tin die aperture should be higher than the outside diameter of 0. 05 mm copper wire as well.
(6) cooling. For tinned copper wire diameter of less than 0. 2 mm, should use air cooling, production can be controlled from the baked good traction and tinned copper wire between. For tinned copper wire diameter of 0. 2 ~ 0. 6 mm, the use of water cooling is better, it can effectively avoid tinned copper due to insufficient cooling at the line after the closing line to produce the phenomenon of stick tin, tin-plated copper guarantee surface quality lines.
(7) to close the line, pulling speed. Closing line, pulling speed should be based on the size of the diameter, taking into account annealing (≥10 s) and copper time (≥0. 03 s) in a tin furnace. For a diameter of less than 0. 2mm thin, towing speed should be controlled at 130 m / min is appropriate. Traction too fast, it will result in insufficient annealing affect elongation, also increases the chances of breakage; slow the copper wire in the annealing furnace is too long time, the line will be stiff.