Why is the slitter knife verticality not good after regrinding, and the outer circle has a taper?
Views : 2563
Author : Summer Xia
Update time : 2021-05-20 16:45:09
In order to save investment, some companies often use the work shaft of roll grinders and slitting machines to sharpen knives. This method is not inevitable, but it is not possible for companies with slitting machines with long arbor and small arbor diameter. Using the long working shaft of the slitting machine to replace the sharpening shaft will inevitably cause the problem of a substantial decrease in rigidity. For a slitter knife with an outer diameter of 180 ~ 250 mm, when the diameter of the sharpening shaft is below 90 ~ 135 mm, the total width should be less than 250 ~ 300 mm. However, the roll is wide and the roll diameter is small, while the outer diameter of the slitter knife is large and heavy. If the factory replaces the short shaft with a long working shaft of the same width as the roll, the long and thin working shaft will deform due to the weight of the blade and its own weight, and will have a strong grinding force in the radial direction of the grinding wheel. The squeeze produces greater deformation. If 300 mm wide blades are placed on one side of the sharpening shaft in groups, the deformation of the sharpening shaft is asymmetrical, and the center axis of the knife set and the guide rail of the grinding head are not parallel, so that the outer circle of slitting knives has a taper after regrinding (see Figure 1). In addition, the operator will also find that the outer diameter of each knife will be different, making it impossible to work. Therefore, the factory must design a special short sharpening shaft. When the roll grinder changes from the state of grinding the rolls to the knife grinding, you must move the tailstock of the grinder.
Fig 1 Reasons for the taper of outer circle of the slitter knife
