Describe the reason of forming copper foil soft connection

1) electrolyte was entered into the sealing groove at the edge of cathode roller, and the sealing apron did not seal the chamfering of cathode roller, so that copper was deposited on the chamfering and connected with the copper deposited in the end face sealing groove of cathode roller. When the copper foil is stripped from the cathode roller, it scrapes the apron and makes the apron creep. Or when the sealing apron is opened, scratch the edge of copper foil, so that the edge of copper foil warped. The electrolyte in the sealing groove immediately infiltrates into the gap between copper foil and cathode roller, and the edge of copper foil is stained with electrolyte, which is corroded to produce blue copper sulfate, and the surface still remains obvious corrosion traces after rough treatment. At the same time, the side of the cathode roller is corroded as the production progresses, even if there is no electrolyte leakage here. Because the edge of the cathode roll has been corroded, the oxidation edge of copper foil here continues to exist, and it becomes more and more serious. Only by re-grinding the cathode roll can it be solved.

2) the air outlet of the electrolytic tank is close to the cathode roll chamfering, resulting in the largest amount of air passing through the edge of the cathode roll and the maximum wind speed. As we all know, cathode roll is not afraid of electrolytic vacuole, most afraid of acid gas in the smoke and exposed in the air, cathode roll edge is close to the electrolytic tank exhaust, here by the wind is the strongest, because the cathode roll edge is generally there is a problem of leakage, so the corrosion is also the fastest. Cathode roll surface is normal, and the edge has caused the oxidation of copper foil, for this, forced to grinding roller. Therefore, the best outlet of the electrolytic cell is located in the direction perpendicular to the cathode roll surface, a little farther away. Prevent some parts of the surface of cathode roller from passing through excessive wind speed and air volume.

3) the extrusion roller or water extrusion roller is too long, or is not installed properly, running to one side, with a sealing apron on the top of the head. When the apron pushed by the extrusion roller wriggle, the edge of copper foil and the cathode roller will be stripped and lifted, creating gaps between the copper foil and the cathode roller. Make the electrolyte permeate into the gap between the copper foil and the cathode roll, causing the edge of the copper foil to be corroded by the infiltrating electrolyte, and then form the blue oxidized edge. At the same time, the edge of the cathode roll is corroded, and the produced copper foil edge is oxidized. Squeeze roll or squeeze roll length is not enough, copper foil edge liquid or water is not squeezed, copper foil edge retained electrolyte or sulfuric acid solution, corrosion of copper foil surface edge, after rolling and the smooth surface corrosion, resulting in oxidation edge.

4) when the extrusion (water) roller or water receiving plate (also the scraping plate) is rubbing against the copper foil, the scraping plate is fixed, and the cathode roll is rotating. During the extrusion, the scraping plate causes the copper foil edge to peel off from the cathode roll, so that the electrolyte penetrates into the inside, resulting in the oxidized edge of copper foil. Had better not scrape liquid board, use squeeze roll effect will be a little better.

5) the electrolyte circulation amount at the edge of the cathode roller is relatively small, and the flow rate is small. The reasons for this are the influence of the sealing apron of the cathode roller and the shielding strip of the anode plate. The electrolyte forms eddy current in the edge of cathode roller, which causes the fine mud and suspended impurities in electrolyte to gather in the edge, resulting in the rough crystallization of copper foil edge. Not easy to be washed clean, not easy to bake very dry, copper foil edge because of rough acid, water content naturally large, cathode roll edge temperature is low, in the cathode roll drying copper foil waterline, the edge is the highest. It can be judged that the edge of copper foil is not dried, and the raw surface of copper foil is in close contact with the smooth surface after winding, because the edge of copper foil coil can contact with air and water, forming an electrochemical reaction, resulting in the corrosion and oxidation of the smooth edge of copper foil.

6) the cathode roller edge grinding roller is not fine, or the edge is not grinding, or the edge grinding time is less. The surface of the roller edge of the cathode is rough, with large surface area, strong suction capacity and fast oxidation speed, and the produced copper foil smooth surface roughness is large, resulting in more coarse copper foil rough surface, resulting in unclean washing and incomplete drying, and the acid gas in the raw surface of copper foil after winding corrodes the smooth surface, resulting in smooth oxidation. Cathode roll grinding must do everything possible to grind the edge of the fine, can not deal with, copper foil production process every small link should be done seriously, can not have the same, can also be thought.