Granulator blade - hob
Hob is divided into gear hob, worm gear hob, non-involute spread into hob and fixed hob, etc., processing, the hob is equivalent to a spiral gear with a large helix Angle, the number of teeth is the number of hob blades, the workpiece is equivalent to another spiral gear, each other according to a pair of spiral gear space meshing.
The material of the hob is generally tool steel, high-speed steel and carbide, etc. At present, the tool steel, the use of the better material is D2, with good mechanical properties; High speed steel, in order to save high speed steel, reduce cost, avoid forging difficulties and improve the metallographic organization, often use insert structure, insert hob structure in many forms, commonly used for insert rack structure, that is, the tooth part of the knife made of high speed steel rack, after heat treatment fastened on the knife body, high speed steel is also called sharp steel, has a good cutting effect; There are also carbide, with carbide steel manufacturing hob, can significantly improve the cutting speed and cutting efficiency.
SHJ knife can provide various knives with different materials and design to meet all kinds of requests.
Factors affecting the service life of grain cutter hob
1. The impact of the cutting gap, the gap between the moving knives. In a certain range, the cutting gap is large, and the cutting force required is small; On the contrary, the cutting force is large, and the wear of the tool is also large; When the gap is close to zero, the cutting force will become quite large, and the edge will be unable to withstand the cutting force and break; However, if the gap is too large, the quality of the slice will also be significantly affected, such as the generation of grain, tailing and so on. Therefore, in the production, the cutting gap must be reasonably selected, and the general cutting gap is controlled at 0.03~0.04 mm.
2. The influence of cooling water, cooling water is indispensable in the pelleting process, it not only cools the casting belt to transport materials, but also has a certain impact on the use of blades. Cooling water can take away the heat generated in cutting in time, reduce the blade wear speed, and can also play a certain lubrication role. However, excessive debrine has an obstructing effect on the operation and slicing of the blade, which will lead to noise and an increase in cutting consumption, while the cooling water will enter the mechanical transmission part, and the solid impurities in the cooling water will wear the blade quickly, so the role of debrine in the cutting process also needs reasonable use control.
3. The effect of titanium dioxide content on the quality of slices, titanium dioxide is a matting agent in polyester production, is an indispensable additive in chemical fiber production, but titanium dioxide has an important impact on the wear of the blade. When the content of titanium dioxide increases, the life of the blade decreases sharply. When the titanium dioxide content is close to zero, the life of the blade can be very long. Without affecting the quality of polyester products, the most reasonable injection amount of titanium dioxide should be maintained as far as possible.
4. The impact of blade processing after normal grinding of the blade, there are many small spikes on the cutting edge, these spikes are sharp but easy to break, the back of the small peak after the fracture leads to an increase in cutting force, generate more heat, shorten the service life of the blade. Therefore, it is necessary to deal with small peaks before use, reduce local stress concentration, improve impact strength, and extend the service life of the blade.
5. The impact of the change of production load on the blade, the change of production load is bound to lead to the change of cutting conditions, the output of the slice increases, the cutting speed and the friction heat generated also increases, and the life of the blade will be shortened.
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