How to determine the sharpening cycle and grinding amount?
Views : 2089
Author : Mr. Jiang
Update time : 2021-05-19 15:14:54
This is a very important subject. If you can master it well, you can reduce the cost of tools and increase the yield of products. In order to be able to determine the sharpening cycle and the amount of each grinding, we must pay attention to the following two points:
1) Always make a record of the processing tonnage and processing time after each sharpening, and grasp the regularity of the sharpening when the processing tonnage and how long it takes.
2) Sharpen the knife frequently. Don't slit coils for a long time with the blade not sharp in order to save the cost of sharpening and increase the output. As a result, the quality of the product will not be good, and the cost of the knife will not be saved. As shown in Figure 1, assuming that the round corner R on the blunt blade of the slitter knife is 0.5 mm, the blade will be sharp again after 0.5 mm is removed. Therefore, the blade always works in a sharp state. However, if the round knife is dragged until the round corner R is 2 mm and then sharpened, the blade will always be in a non-sharp state, and in the end, the blade will need to be ground off by 2 mm. This is very uneconomical.
1) Always make a record of the processing tonnage and processing time after each sharpening, and grasp the regularity of the sharpening when the processing tonnage and how long it takes.
2) Sharpen the knife frequently. Don't slit coils for a long time with the blade not sharp in order to save the cost of sharpening and increase the output. As a result, the quality of the product will not be good, and the cost of the knife will not be saved. As shown in Figure 1, assuming that the round corner R on the blunt blade of the slitter knife is 0.5 mm, the blade will be sharp again after 0.5 mm is removed. Therefore, the blade always works in a sharp state. However, if the round knife is dragged until the round corner R is 2 mm and then sharpened, the blade will always be in a non-sharp state, and in the end, the blade will need to be ground off by 2 mm. This is very uneconomical.
Figure 1 Comparison of timely and non-timely sharpening
In addition, you must grind a certain amount each time you sharpen the knife. Regardless of whether it is cutting copper or stainless steel, any such continuous cutting will produce tiny cracks invisible to the naked eye on the outer surface of the blade. This kind of tiny cracks often deep into the cutter body between 0.04 ~ 0.1 mm (see Figure 2). If they are not thoroughly ground, the remaining tiny cracks will continue to expand and extend under the repeated action of shear stress, causing small pieces of the cutter body to peel off. Figure 3 is a photo of grinding the outer circle of slitter knife.
Figure 2 An enlarged view of the micro cracks on the surface of the slitter knife
Figure 3 Grinding of the OD surface of the slitter knife
