The sharpness and service life of the paper cutter's knives largely determine the production efficiency of the paper cutter. The use effect and life of the knife depend on four major factors: the knife material, the shape and angle of the knife, the quality of the knife and the type of material being cut.
1. Knife material
The knife of a single-piece paper cutter is made of a blade and a knife body welded at high temperature. The blade is made of high-hardness chromium-tungsten-manganese steel, and the knife body is made of low-carbon steel. The durability of the knife is proportional to the hardness of the steel used in the blade part. For high-quality blades, the hardness of the blade can reach HR55~60 after quenching.
2. The shape and angle of the knife
On a single-sided paper cutter, a single-edged knife is generally used, and its grinding angle is between 19° and 23°. However, this shape of the knife is not an ideal shape. The bevel surface of the knife bears the pressure from the part of the paper stack to be cut during the cutting process, so the bevel surface of the blade is quickly worn out under the friction of the paper edge. Double-sided blades have obvious advantages. Their sharpening helps reduce the load of the machine and improve the accuracy of cutting.
The smaller the angle of the blade, the sharper the blade, the smaller the cutting resistance of the cut material to the blade, the smaller the wear and power consumption of the machine, the neater the cut product, and the smoother the cut. However, if the sharpening angle is too small, the strength and wear resistance of the blade will be reduced accordingly, and the cutting speed and cutting quality will decrease. Therefore, under the premise of the tool material allowing and taking into account the size of the cutting resistance of the cut material, the sharpening angle should be as small as possible.
3. The quality of sharpening
The quality of sharpening depends on the manufacturing materials and equipment, the sharpening process specifications and the technical level of the operator. The higher the quality of sharpening, the longer the service life of the cutter and the better the cutting quality.
4. The type of cutting material
During the cutting process, the speed at which the blade becomes blunt is related to the wear resistance of the cut material. When cutting paper, the speed at which the blade becomes blunt is related to the hardness and ash content of the paper. The blade will dull faster when cutting harder, ash-rich papers.
