General Rubber Sheath Cable is 5 copper conductor as conductive core, in its production process, often found copper conductor oxidation discoloration, which seriously affected the quality of products, has become a large number of domestic cable manufacturers a long-standing technical problems. Copper is a transition metal and is easily oxidized to black cuo by oxygen in the air under acidic conditions. When a copper conductor has a water film or droplets on its surface, because the atmosphere contains a lot of dust, such as smoke, coal, automobile exhaust, chlorides and other acids, alkali, salt particles, such as dust, these harmful substances dissolved in the water membrane or droplets, you can form an electrolyte, thereby increasing the oxidation of copper conductor color. Light affects the product appearance quality and product quality, heavy will affect the use of copper conductor, resulting in the waste of production costs.
Therefore, the copper conductor must be properly kept, pay attention to prevent oxidation discoloration. Metal copper for cable from the principle of the main physical methods of blocking copper and humid air contact, cathodic protection Oxidation reduction method to prevent copper conductor oxidation, chemical methods on the copper conductor surface to create a passive film to prevent oxidation, or spraying special liquid on the conductor surface protection.
Taking the general rubber sheath cable as an example, the main method of preventing oxidation control in each procedure is presented.
1, copper rod before entering the plant transport, testing and storage Most of China's cable enterprises with copper for outsourcing, should choose high quality metal copper rods, standardize supplier transport, delivery process and system, copper rod into the factory inspection in accordance with GB/T 3048.2 or cable enterprises to carry out the standard. Copper rods can be stored in plastic sheeting or plastics covered with copper rods, that is, the simplest physical barrier method to prevent the copper rods and moist air contact.
Workshop with copper rods must be a copper rod coil for the naked eye check whether there is blackening phenomenon, from the source of production control.
2, copper rod drawing Process Control The drawing system of 0.4mm monofilament is generally made up of continuous annealed copper pulling machine and medium pulling machine, which need to be put in line, brushed and annealed, cooled, dried and received. First of all, should choose the appropriate mold, must not be too small, otherwise it will force the lattice variation of metal copper, increase the sharp rise in metal temperature. Second, check the ph of the emulsion before the boot, to ensure that alkaline solution, at the same time drawing oil should be added antioxidants in the copper conductor surface to form a passive film, to prevent oxidation, when the line, keep the line tension stable, uniform, not excessive vibration; In the process of drawing, the operator should ensure the proper water level and ensure the degree of annealing uniformity, Avoid annealing or excessive annealing, the copper conductor surface should not have residual liquid, can be placed in front of the line to place a dry felt (often replaced), to ensure the drying of monofilament.
Finally, in the drawing down after the disc with transparent plastic film sealed, stored in a dry environment, to be circulated, otherwise it will be due to the high temperature of the conductor surface and easy and humid air oxidation risk.
3, copper wire stranded (twisted) and insulating rubber, sheathed rubber extrusion process In the case of copper wire stranding, conductor in the process of the stranding, through each road die to make the metal crystal lattice change the structure, under strong external forces, the copper conductor temperature than before the die before the greater increase, so the copper conductor outer layer is easy to oxidize. It can be used in the cutter and the process of infusion hose will be antioxidant (0.3% of benzene and triazole alcohol solution) into the copper wire, drip standard to just infiltration of copper wire surface, to avoid too little local oxidation or excessive waste of the phenomenon occurs, in all the preparation for safe oxidation, and then turn on the operation.
The receiving line should ensure that the reel is dry and the receiving line is full and sealed with transparent plastic film. The conductor should be wrapped or wrapped in the polyester belt before the insulation, and the material in the rubber insulating material shall corrode the conductor.
Insulating rubber and sheathed rubber in the extrusion process, should avoid the head of water, and the occurrence of hair oxidation black phenomenon. We find in our daily production observation that by selecting high quality copper rods, effectively controlling the drawing process and emulsion concentration and temperature, annealing technology, the passivation of conductor stranded or twisted copper wire surface, and preventing the head from Influent, in addition, the workshop operators should establish quality consciousness, strengthen business training, Can clearly recognize the adverse consequences of copper wire oxidation, strict quality, in order to effectively control the quality of copper conductor cable, to prevent its oxidation, greatly improve the work efficiency and reduce rework frequency, so as to reduce costs and improve the intrinsic product quality beneficial effects.