Comprehensive understanding of shredder blades, how to choose shredder blades correctly

  • release time: 2021-05-22

1. The importance of shredder blades

During the entire operation of the shredder, the main accessory is the blade. The shredder uses the blade to shred metal or plastic.

The shredder blade is made of high-quality alloy steel forging and can be used to shred various scrap metal materials. Customers can choose the appropriate blade according to the type and material of the material to be shredded. Adjusting the thickness and number of blades can obtain the ideal shredding particle size and output.

With the rapid development of science and technology in my country, my country has also become an industrial power. When it comes to industry, it is definitely inseparable from machinery. At the same time, the emergence of machinery has changed my country's manual production, greatly improved production efficiency, and reduced labor production costs. However, the types of machinery are very wide, basically covering all industries. Here, the editor will give you a detailed introduction to the core component of the current waste recycling machine shredder, the shredder blade.

When customers buy shredders, they should actually carefully understand the blades used by manufacturers, because the price of shredder blades has accounted for about 20% of the cost of the machine itself. Shredders have now become the main products of the recycling machinery industry. Its power is large, and its productivity is greatly improved compared with traditional shredders, which is proportional to the speed at which humans create life and industrial waste.

Of course, the raw materials that can be crushed by the shredder are also diverse. Such as: wood, tires, plastics, films, circuit boards and other industrial raw material wastes from different industries. Naturally, the requirements for blades are also very important. The requirements for hardness are even more important. Shredder knives have also become one of the important research objects of manufacturers. Shredder blades are divided into multi-axis and single-axis. The blades of single-axis are square-shaped, while the blades of multi-axis are round and have claws. The commonly used claws are two claws, three claws, six claws, eight claws and twelve claws. The number of claws, the gap and the distance from the blade to the spacer determine the size of the shredded material. Commonly used multi-axis shredder blades include double-axis knives, three-axis knives and four-axis knives. The materials should be steel with good wear resistance, good toughness, high strength and strong impact resistance. Commonly used tool materials include 6CrW2Si, 42CrMo, SKD-11, D2, DC53, LD, Cr12MoV and other high-performance special steels, which can meet the processing of various materials in the resource recycling industry. The tools, knife shafts and spacers can be customized according to customer needs.



Shredder and blades

 Processing process standards and steps for shredder blades

The shredder blades should be strictly processed according to the processing process and standards, otherwise it will directly affect the service life of the shredder blades. The general processing standards and processes are as follows.

1. Processing process of shredder blades

The processing and production steps of shredder blades are as follows:

(1) Material selection;

(2) Cutting and forging;

(3) Tempering;

(4) Primary processing;

(5) Heat treatment;

(6) Surface grinding;

(7) Wire cutting;

(8) Fine grinding.


Shredder blades

Shredder blade processing steps and standards

(1) Selection of raw materials

Shredder blades generally use steels such as Cr12mov, w6mo5cr4v2, w18cr4vSKH, and M2. The better quality ones generally use Japanese SKD11 steel. The shredder blades produced with this kind of steel are not only wear-resistant, but also not easy to break, and the shredding effect is also good. If it is used to shred waste materials such as rubber, fiber, and paper, 9CrSi alloy tool steel is generally used. The shredder blades produced with this kind of steel are not only very hard, but also relatively brittle and wear-resistant. In short, the choice of raw materials depends on the type of shredder.

(2) Cutting and forging

According to the shredder blade drawings, the steel is cut. Generally, a laser cutting machine is used for cutting, which is not only accurate, but also has smooth edges and is easy to process later. Subsequently, the blank is forged. During the forging process, the blank is inspected for flaws. If cracks or unqualified blanks are found, they are removed and recycled. Unqualified blanks should not be processed further.

(3) Tempering

The forged blank is tempered to perform preliminary heat treatment. Generally, the tempering temperature is not high. The purpose of tempering is mainly to transform the blank into troostite.

(4) Primary processing

The tempered shredder blade blank is processed initially. The blank is forged to remove surface impurities. The blank should be kept as flat as possible to avoid increasing the workload in the later stage. The pre-processed blank is prepared for heat treatment.

(5) Heat treatment

The pre-processed shredder blade blank is heat treated. The main purpose is to improve the mechanical properties of the shredder blade. It is heated at high temperature and then cooled rapidly to transform the steel material into martensite. During the heat treatment process, the deformation of the steel should be taken into consideration. The deformation of the material should be controlled to ensure the quality of the blade. (6) Surface grinding

Surface grinding is performed on the processed shredder blades. Surface grinding is mainly to remove surface impurities. During the surface grinding process, try to leave a 0.3mm margin to reduce the workload of the fine grinder. Surface grinding is performed on a grinder. The surface should be polished before wire cutting.

(7) Wire cutting

The wire should not be too fast during wire cutting. It should be perpendicular to the plane. When wire cutting the inner hole, it should be processed according to the dimensions provided in the drawing to avoid affecting the later use and the installation of the equipment.

(8) Fine grinding

Fine grinding is a process before the end of the shredder blade processing process. It is mainly to polish and process the shredder blade, and then conduct hardness testing. After passing the test, it can be offline and then packaged.

The above is the detailed process and introduction of the shredder blade processing and production process. Each process directly affects the quality and service life of the shredder blade, so the relevant processing technology standards and precautions must be followed.


Shredder blades

3. How to choose the material of shredder blades

There is a lot of controversy about the quality and service life of shredder blades in the market. Many users have experienced blades that are either broken or blunt and not durable. Most of these phenomena are caused by the supplier's selection of blade materials or unprofessional processing technology; the selection of shredder blade materials accounts for a large part of the factors. Now most shredder blades are mainly made of alloy materials such as Cr12Mov, D2, H13, 55SiCr, etc., but it is critical for customers to shred different solid wastes to select a correct material. You cannot blindly pursue factors such as low price or high material hardness to select and determine a material.

Material: 6CrW2Si, 42CrMo, SKD-11, D2, DC53, LD, Cr12MoV

Specifications: conventional specifications, spot supply, non-standard can be customized according to drawings;

Features: strict material selection, advanced technology, high precision, high wear resistance;

Scope of application: industrial raw material waste in different industries such as metal, wood, tires, plastics, films, and electric boards;

What are the application ranges?

1. This product can crush large blocks, baskets, pipes, plates, wood, tires, cans, plastic bags, cardboard, tablecloths, and large rolls of film that are difficult to crush with a single-axis crusher;

2. The combined structural frame is precisely processed with extra-thick plates, the powerful rotating shaft of large-angle hexagonal columns, and the large-caliber solid input hopper, so large raw materials can be safely put in;

3. The rotary knife is uniquely designed and processed in terms of thickness, shape, and arrangement order, with strong shearing force and sharp blades, and can crush efficiently;

4. PLC control, when the processed material is too large or too much, it is equipped with forward and reverse operation and shutdown functions, and the safety measures are foolproof;

5. Low-speed operation, low noise, and less dust;

6. The cutter is made of special alloy steel, which is sturdy and durable; low transmission speed, low noise, large torque, mechanical and electrical overload, more suitable for crushing extra-large and extra-thick miscellaneous items.

In summary, the shredder blade is the core component of the shredder. A good blade can greatly improve work efficiency. The editor here gives you a small suggestion. After daily use of the shredder, you should check it and pay more attention to maintenance. After all, the machine cannot work endlessly. Only in this way can the service life of the shredder be extended.

The single-axis shredder blade mainly crushes soft materials such as plastics. We must choose materials with high quenching hardness, wear resistance and impact resistance. Now most of them choose Cr12MoV, D2, DC53, and the general hardness can reach HRC60°. Some customers with high requirements will even use more expensive LD (7Cr7Mo2V2Si), W6Mo5Cr4V2, etc. The hardness reaches HRC62° or above. It contains high alloy elements such as W and Ni, which are more wear-resistant and impact-resistant, making the shredder blade have a longer service life, reducing the frequency of blade change, and more cost-effective.

The blades of double-axis shredders and four-axis shredders are mainly made of 55SiCr, H13 and other materials, but this is only for some common objects and general service life, such as plastic bottles, wood, household garbage, cans, ordinary metals, etc. For some customers with high requirements, high-strength shredding and long service life, we have to choose the right material for shredding different objects. The double-axis shredder shreds some relatively soft metal materials such as aluminum and copper, or some plastics and rubber materials. If the service life is long, we must choose materials similar to D2, LD, etc. , because aluminum, plastic, rubber and other materials are sticky, after a period of shredding and extrusion by the double-shaft shredder, these materials will inevitably heat up and stick to the blades. Therefore, in order to have a long service life and uniform shredded particles, these materials with strong hardening and wear resistance must be selected; for the shredder blade to shred some high-strength steels such as automobile plates, beam steel and other metal materials with a yield strength of more than 550Mpa, or even more than 1000Mpa, it is necessary to select H13Ni, HMB and other impact-resistant and tough materials to avoid the phenomenon of blade not breaking or blunting.

Reasonable selection of shredder blade material will definitely bring win-win benefits to customers and suppliers, which can not only ensure the service life of blades and machines, reduce the frequency of blade changes, increase customer production, maximize customer benefits, but also ensure that suppliers can obtain more customer resources.


Plate shredder






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