1. Feed machinery equipment accessories screen product introduction
In the feed production process, the screen is a very critical accessory, its main role is to screen feed raw materials or finished products to separate different particle sizes of particles, to ensure the quality and uniformity of feed products, while removing impurities, improve the purity and safety of feed. Whether in the pretreatment stage of raw materials, or in the post-processing of finished products, the screen plays an indispensable role, and its performance directly affects the efficiency and quality of feed production.
2. Type of structure
Braided screen
Woven screen is the most common type of screen structure, which is composed of metal wire or non-metal wire in accordance with a certain weaving method. Common weaving methods include plain weave, twill weave and satin weave. The structure of the plain woven screen is relatively simple, and the warp and weft wires are interwoven, and each warp and weft silk are alternately passed up and down to form a uniform grid. This braided screen has high stability and strength, and is suitable for occasions where the screen strength is required to be high and the screening accuracy is relatively low, such as the initial removal of large particle impurities in feed raw materials. Twill weaving is when each warp or weft wire is alternately crossed over two or more wires to form a diagonal grain. Compared with plain woven screen, twill woven screen has smoother mesh surface, better material passability and higher screening efficiency, and is often used for feed grading screening with certain requirements for screening accuracy. The woven structure of the satin woven screen is more complex, and its silk or weft wire is interwoven in a jump on a number of wires, forming a smooth and beautiful mesh surface, with good material passability and high screening accuracy, suitable for fine screening feed products, such as pet feed, aquatic feed and other products with high particle size uniformity requirements. The aperture size of the braided screen can be achieved by adjusting the diameter of the wire and the braided density, the general aperture range from tens of microns to tens of millimeters, can meet a variety of different particle size requirements of the screening operation.
Perforated screen
Punching screen is a screen made by punching holes on the metal sheet. The production process is to first cut the metal sheet according to the required size, and then use the punching mold to flush out a series of evenly distributed holes on the plate. The hole shape of the punching screen is various, the common ones are round, square, rectangular, diamond and so on. The round perforated screen has the characteristics of uniform force and not easy to clog, which is widely used in the coarse screening of feed raw materials and some screening operations that do not require high particle shape. Square perforated screens have advantages in some specific feed product screening, such as in the screening of feed with approximately square particles, square holes can better achieve particle separation and screening. Rectangular perforated screen is suitable for the screening of long granular feed, such as the processing of some grass feed. Because of its special hole structure, diamond punching screen has better stability when it withstands greater impact force, and is often used in some heavy feed screening equipment or screens that work in harsh environments. The aperture accuracy of the punching screen is relatively high, and the size and shape of the hole are consistent, which can ensure the more accurate screening effect. Its aperture size is generally based on the specific needs of feed production, from a few millimeters to tens of millimeters have applications.
Electroforming screen
Electroforming screen is a kind of high precision screen made by electrochemical principle. It is in the metal template through the way of electrodeposition, the metal ions gradually deposited into the mesh structure of the screen. The mesh wire of the electroforming screen is very thin and uniform, and can create a very small aperture, which can generally reach a few microns or even smaller. This screen has extremely high screening accuracy and can screen very fine feed particles or impurities, such as in some special feeds or in the production process requiring very high feed purity, for the removal of small impurity particles or for the precise screening of feed additives. The electroforming screen has high flatness, regular shape of screen hole and good consistency, which can effectively improve the accuracy and efficiency of screening. However, the manufacturing process of the electroforming screen is more complex, the cost is higher, and the strength of the screen is relatively low, and it needs to be more careful in the use process to avoid being damaged by a larger external impact.
3. Material characteristics
Stainless steel
Stainless steel is one of the commonly used materials for feed screens, such as 304 stainless steel and 316 stainless steel. 304 stainless steel has good corrosion resistance, oxidation resistance and certain strength, which can resist the erosion of moisture, acid and alkali components and microorganisms in the feed production environment to ensure the long-term stable use of the screen. In the general livestock feed and ordinary aquatic feed production, 304 stainless steel screen can meet the screening requirements, and its surface finish is good, conducive to the passage of materials, reduce the adhesion and blockage of materials. 316 stainless steel is more excellent in corrosion resistance, containing molybdenum element makes it able to work in a more severe corrosive environment, such as in some feed production containing high concentration of salt or strong acid and alkali additives, 316 stainless steel screen can effectively prevent corrosion, to ensure the service life of the screen and screening effect. The material characteristics of the stainless steel screen make it easy to clean and maintain, in line with food grade hygiene standards, to ensure the quality and safety of feed products.
Mild steel
Low carbon steel screens, such as Q235 carbon steel, have high strength and relatively low cost. In some cases where the screen strength is required to be high and the feed production environment is relatively good, there is no highly corrosive medium, low carbon steel screen is an economical choice. For example, in the raw material screening link of large feed processing plants, when processing a large number of grains, beans and other raw materials, the Q235 carbon steel screen can withstand the greater impact force and the weight of the material, effectively separating large particles of impurities. However, the corrosion resistance of low carbon steel screen is poor, it is easy to rust in the environment of wet or corrosive media, and it is necessary to carry out appropriate anti-corrosion treatment, such as galvanized, spray painting, etc., to extend its service life.
Galvanized steel wire
Galvanized steel wire screen is a screen product after galvanized treatment on the surface of low carbon steel wire. The galvanized layer can effectively improve the corrosion resistance of the steel wire, so that it can resist moisture and slight acid and alkali erosion in the feed production environment to a certain extent. Galvanized steel wire mesh combines the strength advantages of low carbon steel and the corrosion resistance of galvanized layer, and is used in some small feed mills or occasions where cost and corrosion resistance are comprehensively considered. For example, in some small rural feed processing points, for processing local livestock and poultry feed, galvanized steel wire mesh can meet the basic screening needs, and the price is relatively close to the people.
4. Performance characteristics
Precise screening accuracy
Screens of different structure types and materials have a certain range of screening accuracy, which can meet the screening requirements of different particle sizes in the feed production process. By adjusting the diameter and weaving density of the wire, different precision screening from coarse screening to fine screening can be achieved. With accurate punching die and processing technology, punching screen can ensure the high consistency of hole shape and aperture, and provide more accurate screening effect; Electroforming screen with its very small mesh diameter and high-precision hole shape, to achieve the precise screening of tiny particles, such as in the screening of some feed additives, can be different particle size additives precise separation, to ensure the accuracy of feed formula and product quality stability.
Good air permeability and material passability
The structural design and material selection of the screen are focused on ensuring good air permeability and material permeability. The mesh structure of the woven screen is relatively loose, which can make the air and materials pass through the screen more smoothly while ensuring the screening accuracy, and reduce the accumulation and blockage of materials on the screen. The design of the hole shape and aperture of the punching screen also fully considers the passability of the material, such as the circular hole and the larger aperture can reduce the resistance of the material through and improve the screening efficiency. Although the mesh wire is thinner, because of its regular and uniform hole shape, it also has good material passability, which can effectively avoid the blockage of the material when screening fine materials and ensure the continuity of the screening process.
Strong wear resistance and durability
In the feed production process, the screen needs to constantly contact with feed raw materials or finished products and withstand the friction and impact of the material, so good wear resistance and durability are important performance characteristics of the screen. Stainless steel screen has high hardness and wear resistance, which can keep the structure and performance of the screen stable in the long-term use process. Low carbon steel screen after appropriate surface treatment, such as galvanized or painted, can also improve its wear resistance and corrosion resistance, extend the service life. For some special materials of the screen, such as nylon screen, although its hardness is relatively low, but has good flexibility and self-cleaning performance, to a certain extent, can reduce the wear of the material on the screen, improve durability. Although the strength of the electroforming screen is relatively low, under normal conditions of use, its high-precision mesh structure and good corrosion resistance can also ensure a certain service life.
5. FAQ
Q: What is the main material of the screen?
A: The screen is usually made of stainless steel wire, low carbon steel wire or high carbon steel wire to ensure that it has sufficient strength and wear resistance. These materials can withstand high loads and long periods of use.
Q: What are the surface treatment processes of the screen?
A: Common surface treatment processes for screens include electroplating, spraying and heat treatment. These processes can improve the hardness and wear resistance of the surface and extend the service life.
Q: What are the special requirements of the screen in different application scenarios?
A: In different application scenarios, the screen may have different special requirements. For example, screens used in high temperature environments need to have high temperature resistance; For use in corrosive environments, corrosion-resistant materials are required.
Q: What are the heat treatment processes of the screen?
A: The heat treatment process of the screen includes quenching, tempering and normalizing. These processes can improve the mechanical properties of the material, increase its hardness and wear resistance, and thus extend the service life of the screen.
Q: Is the dynamic balance test of the screen important?
A: Very important. Dynamic balance testing ensures that the screen remains stable when rotating at high speeds, reduces vibration and noise, and improves the operating efficiency and life of the equipment. Screens not tested for dynamic balance can lead to premature wear and failure of equipment.
