lubrication, temperature and oxidation of copper wire drawing process

- Apr 20, 2018-

 In China's cable industry and copper, enameled wire industry in the process of drawing copper wire, the general presence of oxidation discoloration, blackening and other phenomena, spring and summer more serious. With the popularization of the existing high-speed machine, drawing speed has been greatly improved, contradictions more and more prominent.


   To these problems and their relationship, I focus on the copper wire drawing process caused by the temperature of the cause of the impact of oxidation lubrication problems:


   As a result of wire drawing process, and friction between the mold directly affects the lubrication effect, so you can analyze from the following aspects: first, the oil content of the fat, the second is the tensile speed and the use of temperature, three is tensile, four is how to prevent the oxidation of black.


   Fat Amount Almost every manufacturer of drawing oil has different fat content, drawing oil of the fat content, viscosity and the use of temperature is the main reason for the impact of lubrication effect.


   The following are analyzed separately:


   The so-called FAT volume can be simply understood as the drawing process in the deformation area of the formation of oil film thickness, drawing emulsion of excessive fat will make the drawing process in the deformation zone formed in the oil film too thick, there are several adverse conditions:


   A, the oil film is too thick, pulling out the copper wire lost the surface gloss


   B, the oil film caused by local uneven and incomplete, resulting in direct contact area increases, increase friction and make out of the product surface with oil spots. C, in addition, the amount of fat emulsion is too high, there will be a part of free out, resulting in emulsion layering and adhesion on copper powder, suspended in the emulsion, sticky dirt mold hole, resulting in blocking the mold eye, and then disconnection.


   Serious will directly lead to the deterioration of lubricating oil, resulting in a full pool replacement, resulting in loss. If the amount of fat is too low, the oil film must be very thin, or can not form a complete oil film.


   In the process of drawing, it is easy to rupture, resulting in the tension of the copper wire and mold contact can not be lubricated, increased friction, will cause the following kinds of adverse conditions:


   A, tensile increase, will lead to frequent disconnection


   B, friction increase, generate heat, oil temperature rise, increase fuel consumption


   C, resulting in lower surface quality of the wire drawing


   D, mold, cone loss of fast, copper powder increased Therefore, we choose copper wire drawing lubricants in accordance with the size of the factory pulled the diameter and determine its need to contain fat amount of copper wire drawing oil concentration and fat content is different, General copper pull oil in the fat content between 70-80%, that is, every 100 kilograms of drawing oil within its fat content of only 70-80 kg,


   So some units according to the use of the recommended concentration to adjust the emulsion oil, according to the 10kg of oil plus 90kg water thought is containing fat and has reached 10%, in fact, it is wrong, the actual amount of fat containing only 7~8kg, so you need a sugar meter to detect its fat content. The method is: at room temperature 24 ℃, 100ml with plug cylinder, add the drawing oil crude oil 10ml then add distilled water to the scale 100ml, plug the cylinder lid, shake up and down about 20 times. To be fully evenly, take sugar meter, first wash with a clean glass mirror with soft paper dry, drop a few drops with a good uniform emulsion on the mirror, Clean it once, erase it.


   And then drip 1-2 drops in the sugar meter mirror, to the brightness of observation, the reading multiplied by 10 times times that the copper drawing oil of the fat content.


   Temperature and tensile speed Drawing oil the use of temperature and lubrication effect is mutually beneficial, mutual impact, such as temperature is too low, the new addition of drawing oil is not easy to emulsification, and its emulsion particle activity will decline, not conducive to lubrication.


    Conversely, the temperature is too high, the oil is easy to decompose, suspended in the emulsion, it reduces the lubrication effect. If the temperature of the emulsion is further elevated without taking effective measures to control its temperature, the oil film in the deformation zone may rupture, resulting in the chemical chain rupture in the process formulation of the drawing oil.


    In this way, the coefficient of friction will be greatly increased, the vicious circle, not only the product surface quality down, but also will make the emulsion temperature rise rapidly, resulting in scrap rate rise. Therefore, it is not negligible to keep the cooling state of high speed drawing emulsion.


The temperature should be controlled under the oil film rupture point, and the cooling tower or heat exchanger should be used for temperature treatment.