In the process of aluminum plate extrusion, it is easy to appear surface peeling or bubbles. What is the reason? How to eliminate it? Now let the aluminum plate manufacturer solve the problem for you!
What is bubble or flaking: convex bubble appears on the surface of the product, common in the head and tail, complete called bubble, has broken called peeling.
1、 Causes of air bubble and peeling during extrusion of aluminum plate
1. The wear of extrusion cylinder and cushion is out of tolerance, the size of extrusion cylinder and extrusion pad is not matched properly, and the diameter difference of gasket used exceeds the allowable value;
2. The extrusion cylinder and pad are too dirty, with oil, moisture, graphite, etc;
3. The lubricating oil contains water;
4. There are too many grooves on the surface of the ingot, which are too deep, or there are pores and sand holes on the surface of the ingot, and the structure is loose and greasy;
5. The cylinder is not cleaned when the alloy is replaced;
6. The temperature of extrusion cylinder and ingot is too high;
7. The ingot temperature and size exceed the allowable negative deviation;
8. Too long ingot, too fast filling, uneven ingot temperature, resulting in non drum filling, so that the exhaust in the cylinder is not complete, or improper operation, and the exhaust process is not carried out;
9. The design of die hole is unreasonable, or the cutting of scrap is improper. The residual material in the diversion hole and diversion hole is partially carried out, and the gas in the space gap enters the surface during extrusion.
2、 Elimination of air bubble and peeling during extrusion of aluminum plate
1. Reasonably design the matching size of the extrusion cylinder and the extrusion gasket, check the tool size regularly to ensure that they meet the requirements, repair the big belly of the extrusion cylinder in time, and the extrusion pad shall not exceed the tolerance;
2. Keep the surface of tools and ingots clean, smooth and dry;
3. Clean the cylinder thoroughly when replacing the alloy;
4. Check the equipment and instruments frequently to prevent the temperature from being too high and the speed too fast;
5. Strictly implement the process procedures and systems;
6. Reasonable design and manufacture of tools and moulds, the diversion hole and the diversion hole should be designed with an internal slope of 1 ° to 3 ° and the operation should be strictly carried out to cut the residual materials correctly and exhaust completely.
Through the expert's question and answer, I believe everyone has a deep understanding of the causes and elimination methods of bubbles and peeling in aluminum plate extrusion. If we avoid these problems in daily production, we can reduce the loss and improve the yield.