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Stainless steel wire mesh plays a vital role in the field of powder screening due to its high strength, wear resistance, corrosion resistance, high temperature resistance, easy cleaning, good dimensional stability, non-toxic and pollution-free characteristics. It is especially suitable for application scenarios with high requirements for precision, hygiene and durability, such as ceramic proppants (ceramsite sand), medicines, quartz sand, etc.
The core advantages of stainless steel wire mesh in the field of powder drying:
1. Excellent mechanical strength: It can withstand the impact, friction and material accumulation pressure during the screening process, and is not easy to deform and break.
2. Excellent wear resistance: Especially for powders with higher hardness (such as quartz sand and ceramic proppants), the life of stainless steel mesh is significantly longer than that of nylon, polyester and other materials.
3. Excellent corrosion resistance: Stainless steels such as 304 and 316L can withstand a variety of chemical substances (acids, alkalis, solvents) and environmental corrosion, ensuring long-term reliability and the purity of the screened materials.
4. Good temperature resistance: It can adapt to process requirements such as high temperature drying and high temperature sterilization (such as pharmaceutical production).
5. High surface finish and non-toxicity: It meets food and pharmaceutical grade requirements (such as FDA, GMP), is not easy to adsorb materials, and is easy to thoroughly clean and sterilize to prevent cross contamination.
6. Accurate and stable aperture: The weaving process is mature, the mesh size is accurate and stable, and the consistency of classification accuracy is ensured.
7. Long life and low overall cost: Although the initial investment may be higher than that of synthetic fiber screens, its ultra-long service life and extremely low maintenance and replacement frequency make the long-term overall cost more advantageous.
Application of stainless steel wire mesh in different powder screening fields:
1. Screening of ceramic proppants (ceramsite sand):
Application scenario: In the production process of ceramsite sand for oil fracturing, the sintered particles need to be graded according to a strict particle size range (such as 20/40 mesh, 30/50 mesh, 40/70 mesh, etc.).
Function of stainless steel wire mesh:
High wear resistance: Ceramsite sand has high hardness (Mohs hardness can reach 7-8), which greatly wears the screen. 316L stainless steel mesh is the first choice due to its excellent wear resistance.
High-precision classification: Precise mesh ensures that the proppant particle size distribution meets the API standard, which directly affects the fracturing effect.
Impact resistance: Withstands the impact of large particles and vibrating screens.
High temperature resistance: Adapts to the screening of high-temperature particles after sintering (high temperature resistant models must be selected).
Easy to clean: The residual dust after screening is easy to clean, reducing contamination between batches.
Common specifications: Multi-layer composite screen (coarse, medium and fine combination) or high-strength single-layer screen, mostly made of 304 or 316L, the mesh range is usually between 10 mesh and 100 mesh, selected according to the target particle size.
2. Screening of drugs (APIs, excipients, intermediates):
Application scenarios: Classification and removal of API powders; screening and impurity removal of excipients (such as lactose and starch); particle size control of intermediates; homogenization of particles before tableting.
The role of stainless steel wire mesh:
Compliance: 316L stainless steel is the preferred material in the pharmaceutical industry, meeting the strict requirements for equipment contact parts (no precipitation, non-toxic, resistant to cleaning disinfectants).
Sanitary and clean: The surface is smooth and has no dead corners, it is not easy to breed microorganisms, and it is easy to CIP (online cleaning)/SIP (online sterilization).
High precision: Ensure that the particle size distribution of active ingredients or excipients of drugs meets the pharmacopoeia standards, affecting solubility, bioavailability and tableting performance.
Corrosion resistance: Tolerant to various cleaning agents (acids, alkalis), disinfectants (such as ethanol, hydrogen peroxide, ozone) and some organic solvents.
Pollution-free: Avoid fiber shedding and contamination of drugs.
Common specifications: High-precision woven mesh (plain or twill), the material is mainly 316L, with a wide range of meshes, from dozens of meshes (removing large pieces) to hundreds of meshes (fine grading/removing impurities). Material certification and surface roughness report are often required.
3. Quartz sand screening:
Application scenarios: In the fields of glass manufacturing, casting, water treatment filter materials, ceramics, building materials, etc., natural or processed quartz sand needs to be graded according to different particle sizes (such as coarse sand, medium sand, fine sand).
The role of stainless steel wire mesh:
Extreme wear resistance: Quartz sand has high hardness (Mohs hardness 7) and is a very abrasive material. High carbon steel or stainless steel (such as 304, 316L, sometimes more wear-resistant models or surface hardening treatment) is the key to resisting its wear.
High load-bearing capacity: Withstand the heavy pressure and vibration of a large amount of sand and gravel.
Weather resistance: Adapt to various indoor and outdoor environments.
Contact us to discuss your requirements of Dashang wire mesh. Our experienced sales team can help you identify the options that best suit your needs.
Precise grading: Ensure that sand for different uses (such as glass raw materials require specific particle sizes, water treatment filter materials have grading requirements) meets the specifications.
Anti-blocking: Reasonable weaving methods (such as twill) help particles pass through and reduce blockage.
Common specifications: According to the processing capacity and particle size requirements, woven meshes with different wire diameters and apertures are selected, and the mesh ranges from a few meshes (coarse screen) to hundreds of meshes (fine screen). Heavy or thickened stainless steel screens are often used.
Precautions for using stainless steel wire mesh in powder screening:
1. Accurate selection: According to material properties (hardness, particle size, humidity, corrosiveness), screening accuracy requirements, processing capacity, equipment type (vibrating screen, drum screen, etc.), working environment (temperature and humidity, corrosive media), select appropriate materials, wire diameters, apertures (mesh), weaving methods and structures.
2. Correct installation and tensioning: Uniform and appropriate tension is the key to ensuring screening efficiency and screen life. Insufficient tension can easily cause the screen to sag, block holes, and channel materials; excessive tension can easily cause the screen to fatigue and break prematurely.
3. Standard operation: Control the feed amount evenly to avoid overload impact.
4. Timely cleaning and maintenance: Regularly clean the residual materials and blockages on the screen. Check the wear of the screen and replace it in time. Avoid using hard objects to scratch and damage the mesh surface.
5. Storage: Store in a dry and ventilated place to avoid extrusion, deformation or contact with corrosive substances.
The Role of Metal Woven Mesh in Plastic Technology
In today's times it would be difficult to imagine that any of the sectors of our daily life, economics or technology, could do without plastics. It is enough to look around us and analyze how many objects are made of plastic to visualize the economic importance of these materials. This importance is reflected in the growth rates that, maintained over a number of years since the turn of the century, outperform almost all other industrial activities and material groups.
Since plastic is so closely related to our lives, do you know how plastic is produced? Plastic production will also use our stainless steel woven mesh. What kind of a role did the wire mesh play? Let’s share it.
In all plastic extrusion processes there is an element called a perforated plate.
This element is inserted at the end of the extruder, between the screw and the nozzle, and consists, as previously stated, of a perforated stainless steel metal disc (with circular perforations of specified measurements) which holds a filter pack- screen, meshes or as it is called in technology: “Screen-Pack”.
The filter pack would be arranged in such a way that the molten material first penetrates, for example, the finer mesh filter and then the coarser mesh filters. Another alternative modality would be to insert it in the filter package, a finer mesh in the middle. Finally, another would be to use the coarsest mesh at the beginning, and the finest at the end. In other words, there is no precise rule in this regard.
The mesh arrangement, illustrated here with fine meshes placed between the coarse ones, as normally recommended, as well as the sinker that supports it. This assembly primarily functions as a filter against foreign material that may have entered the hopper. It also helps to increase the back pressure in the barrel and thus improve mixing and homogenization of the melt.
A typical Screen-Pack might consist of 20/40/60 mesh. However, this arrangement varies according to the material being processed, the process to be carried out and the length of the screw.
For example, for the transformation of Polyethylene into a film, a relatively light "Scree-Pack" is recommended, that is, 20/80/20mesh; this taking into account that the "balloon" is extruded vertically from a current matrix. The characteristics of the metal disc or "Breaker-Plate" and its optimal use, is accomplished by drilling holes from 1/16" to 1/8" in diameter, over 30 - 35% of the total area of the disc, arranged in the shape of holes and symmetrical.
The quantity and specifications of the sieves depend on the machine and the type and characteristics of the resin to be worked on.
Basically the function of the "Breaker-Plate" and the "Screen-Pack" is to filter any foreign material that may be present in the molten material, but it also has the following functions:
1. Break the flow of molten plastic material, distribute it properly, and give a consistent forward movement, with controlled back pressure.
2. Prevent the continuity of cold portions of material until it has the same plasticity as the rest of the material.
3. Retain, in general, impurities and especially "gels" and agglomerates that could contaminate the desired final product.
4. Check the pressure developed by the extruder.
5. It transforms the helical movement provided by the screw by melting a more regular parallel flow.
Regarding the above, the arrangement of the meshes can influence the progress of the extrusion in different ways: For example, the counter-pressure in the dosing area can be significantly increased by using a fine mesh arrangement. This back pressure effect occurs at the lower temperatures and pressures that are characteristic of blown film extrusion. Higher back pressure at a given screw speed improves mixing and homogenization, and therefore extrusion quality, although it may slightly reduce throughput. However, it should be noted that increasing the melt temperature somewhat, using a more complex mesh arrangement, increases the pressure and generates additional frictional heat.
By increasing the number of wire meshes, or their fineness, the friction of the melt by retention in the cylinder increases, and consequently the temperature, an increase that must be adjusted with a decrease in the heat supply by the resistances. .
The higher the back pressure, with the same motor speed, the mixing and homogenization of the resin increases, with the consequent improvement in the quality of the product. If there is more back pressure, the hourly production of the machine must decrease, a situation that we can correct by increasing the motor speed.
Some extrusion operations require such frequent filter changes that it has required machine manufacturers to design an automatic filter change (Automatic Filter Changer). With such a mechanism, it is possible to verify a filter change in tenths of seconds, automatically, but its basic use will depend on its applicability, and where your investment allows the process. With this system the painful work of changing filters is eliminated; interrupt the operation; the loss of time with this entails; the waste produced. Taking into account that this change in some cases can last from 15 to 30 minutes, and in some cases more complicated. New technologies include a self-cleaning filter system in the machinery, which not only allows the automatic change of filters but also the reuse of filters occluded with contaminants. These equipments have two breaking plates with filters. When one of the filter meshes is saturated with contamination, a small flow of the same molten material is passed in counterflow (purge), which results in the elimination of contaminants; meanwhile, the other filter remains in operation. These self-cleaning filters are very useful when it comes to extruding heavily contaminated material (example: recycled material).
Filter mesh
Filtering meshes for extrusion are made up of tightly woven metal mesh. Depending on the type of weave and diameter of the wires, its filtering power will depend. The metallic wires can be made of galvanized steel, chrome steel, chrome-nickel steel, chrome-nickel-molybdenum steel, titanium, etc.
The shapes of the filtering meshes are very varied and will depend on the shape of the breaker plate, as well as strips or rolls of filtering mesh used as continuous filters that run as they become clogged with contaminants.
Source knowledge of Ing. Mariano's blogger. If you are interested, you could learn more from his blogger about plastic technology.
Hebei Dashang is a professional manufacturer of metal woven filter screens,according to exturder filter shapes, we offer circle, belt and kidney-shaped extruder filters in a variety of weave types and sizes to meet the requirements of your specific requirements for filtration.
For more information, please visit Stainless steel sintered felt.