In the forming process of stamping products, most of the products will be scratched. Why? This is because when we bend, there will be friction between the punch and the material surface, and whether the material is hard or not, so there will be scratches. So if we ask the product to have no scratches, how can we eliminate them?
First of all, if we want to solve the surface defects, we must first find out why there are defects and what causes them. When we use ordinary structure to bend, because there is relative sliding between the bending punch and the material surface, and the material is soft, it will inevitably leave scratches on the material surface. As shown below:
We should check whether there are iron filings or other foreign objects on the surface or inside of the product before forming, whether there are many burrs on the bending edge, whether the material meets the stamping requirements, etc. These are the factors that lead to scratches on the punched products.
The way to minimize scratches is as shown in the following figure. Change the structure and turn sliding friction into rolling friction.
Some people think that it is troublesome to engage in roller structure and it has no effect. In fact, it is a problem that the technology is not in place; There are still some products that can’t use this structure because of the shape limitation. The surface of structural inserts can be plated with titanium and chrome to increase the smoothness. This method is also possible, but the effect is not so good.
If the effect of rolling wheel and titanium plating still can’t meet the product requirements, you can also prevent scratches by adding stamping oil and sticking plastic film on the surface of the material, but the cost is not small.
There is also a flap structure, which has no relative friction, so if we want to completely stop this phenomenon, we can adopt this structure if conditions permit.