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In the field of plastic processing, extruders play a crucial role. And the screw elements in extruders are one of the core components that determine the extrusion effect.   I. The importance of extruder screw elements Extruders push plastic raw materials forward through rotating screws and heat, mix, and plasticize the raw materials in this process. The design of screw elements directly affects the performance of extruders, including output, quality, and energy consumption.   II. Types and characteristics of mixing elements ZME element ZME elements are mainly used for distributive mixing. They can mix different materials in plastic melts using special shapes. This kind of element usually has high mixing efficiency and can effectively improve the uniformity of products. TME element TME elements are also a kind of screw element for distributive mixing. Their characteristic is that they can achieve rapid material transfer and mixing in melts. TME elements are usually used in combination with other types of screw elements to achieve better mixing effects. SME element SME elements mainly achieve mixing through shear action. They can generate high shear forces in plastic melts and fully disperse and mix materials. SME elements are suitable for occasions with high mixing requirements, such as the processing of high-performance plastics. III. Application fields of mixing elements Mixing screw elements are mainly applied in the following fields: Plastic modification: In the process of plastic modification, different additives and fillers need to be fully mixed with the plastic matrix. Mixing elements can improve mixing efficiency and ensure that the modified plastic has good performance. Masterbatch production: Masterbatch is a kind of plastic particle containing high-concentration pigments. In the production process, pigments need to be evenly dispersed in the plastic matrix. Mixing elements can achieve efficient mixing and ensure the color uniformity of masterbatch. Engineering plastic processing: Engineering plastics usually have higher performance requirements and need precise mixing and plasticization. Mixing elements can meet the processing needs of engineering plastics and improve product quality.   IV. Selection and optimization of mixing elements When selecting mixing elements, the following factors need to be considered: Types and properties of plastics: Different plastics have different fluidities and mixing requirements, so suitable mixing elements need to be selected. Processing technology: Different processing technologies also have different requirements for mixing elements. For example, factors such as extrusion speed and temperature will affect the mixing effect. Product requirements: Choose the right mixing elements to make sure the product is of the right quality. To optimize the mixing effect, the following measures can be taken: Reasonably combine different types of mixing elements: Choose multiple mixing elements to use together to make the most of their strengths. Adjust the screw speed and temperature: Changing the screw speed and temperature affects how plastic melts. Optimize the screw structure design: The structure design of the screw also has a great influence on the mixing effect. The mixing efficiency can be improved by optimizing parameters such as the pitch and depth of the screw.   V. Summary The mixing elements in extruder screws are important for processing plastic. By choosing and improving these elements, plastic products can be made to a higher standard for different uses. In the future, as technology advances, so will the design and use of these elements.

Our extruder shafts come in sizes from Φ10 to Φ300, allowing us to serve many different industries and needs. Nanxiang Machinery's products are used by well-known brands such as Coperion, Lerstritz, Berstorff, KOBE and JSW. They are found in industries such as plastics, food, feed, pharmaceuticals and new energy.   We have modern equipment including CNC spline milling machines, semi-automatic spline milling machines, machining centres, precision lathes and grinding machines, etc.   Our shafts are made from high-quality 40CrNiMoA steel, which is durable and hard with a rating of HRC45. We also offer custom materials like stainless steel, nickel alloys, and hardened tool steel for special needs.   We use top-quality spline cutters to create precise splines, including rectangular keys and involute splines, ensuring a tight fit, strong torque resistance, and minimal gap for perfect assembly.   Large Inventory and Custom Services   We have thousands of shaft designs and many specialized tools, allowing us to quickly meet customer needs. We also offer custom manufacturing based on your drawings or samples, ensuring a perfect fit for any twin-screw extruder.   Our extruder shafts are built for tough environments, whether in plastics or pharmaceuticals. We help customers run long-lasting, efficient operations.   Conclusion   We focus on making high-quality parts to help our customers work more productively. With our modern manufacturing and top materials, our shafts are reliable and cost-effective.

Extrusion is a kind of batch forming process.In this process, the workpiece metal is forced or compressed through the die hole to achieve a certain cross-sectional shape.   In short, extrusion is a metal processing process that includes forcing metal through a die hole under increased pressure to compress its cross-section.   Thanks to the development of extrusion technology, the world has begun to rely on extrusion to produce bars, pipes and hollow or solid profiles of any shape.   Because this operation involves pushing or pulling the blank through the die, the force required to extrude the blank is quite large. Hot extrusion is the most commonly used method because the deformation resistance of metal is lower at high temperatures, while cold extrusion is usually only performed on soft metals.   History: Although the concept of extrusion was born from the molding process. According to records, in 1797, an engineer named Joseph Bramah applied for a patent for the extrusion process. The test included preheating the metal and then forcing it through the die cavity to manufacture pipes from the blank. He used a manual plunger to push the metal.   Bramah invented the hydraulic process after inventing the extruder. Then, Thomas Burr combined various technologies using hydraulic press technology and basic extrusion technology to produce pipes (hollow). He also obtained a patent in 1820.   This technology then became a basic need for the constantly evolving world, and this process is not suitable for hard metals. In 1894, Thomas Burr introduced the extrusion of copper and brass alloys, bringing about the development of extrusion technology.   Since the invention of extrusion technology, this process has developed into multiple technologies capable of producing products with various complex structures at the lowest possible cost.   Classification or types of extrusion processes:   1. Hot extrusion process: In this hot extrusion process, the blank is processed at a temperature higher than its recrystallization temperature. This hot processing can prevent the workpiece from work hardening and make it easy for the punch press to push it through the die.   Hot extrusion is usually carried out on a horizontal hydraulic press. The pressure involved in this process can range from 30 MPa to 700 MPa. For intact high pressure, lubrication is adopted. Oil or graphite is used as lubricant for low-temperature profiles, and glass powder is used for high-temperature profiles. Provide heat between 0.5 Tm and 0.75 Tm for the blank to obtain high-quality operation.   Hot extrusion temperatures for several commonly used materials are as follows:   Material temperature (°C): aluminum 350 to 500, copper 600 to 1100, magnesium 350 to 450, nickel 1000 to 1200, steel 1200 to 1300, titanium 700 to 1200, PVC180 nylon290.   Advantages: ● Deformation can be controlled as required. ● The billet will not be strengthened due to work hardening. ● Requires less pressure. ● Materials with premature cracks can also be processed.   Disadvantages: ● Poor surface finish. ● Dimensional accuracy will be affected. ● Reduce container life. ● Possibility of surface oxidation.   2. Cold extrusion: This is the process of shaping metal by hitting metal with a bullet. This knocking is done by a punch or punch in a closed cavity. The plunger forces the metal through the die cavity, transforming the solid blank into a solid shape.   In this process, the workpiece is deformed at room temperature or slightly above room temperature.   For too much force required, a powerful hydraulic press is used in this technology. The pressure range can reach 3000 MPa.   Advantages: ● No oxidation. ● Increase product strength. ● Tighter tolerances. ● Improve surface finish. ● The hardness is increased.   Disadvantages: ● Requires greater force. ● More power is required to run. ● Non-ductile materials cannot be processed. ● Strain hardening of the extruded material is a limitation.   3. Warm extrusion process: Warm extrusion is the process of extruding blanks above room temperature and below the recrystallization temperature of the material. This process is used in cases where microstructural changes in the material must be prevented during extrusion.   This process is important for achieving the proper balance of required force and ductility. The temperature of any metal used in this operation can range from 424 degrees Celsius to 975 degrees Celsius.   Advantages: ● Increased strength. ● Increased hardness of the product. ● Lack of oxidation. ● Very small tolerances can be achieved.   Disadvantages: ● Non-ductile materials cannot be extruded. ● In addition, there is a heating device.   4. Friction extrusion: In friction extrusion technology, the blank and the container are forced to rotate in opposite directions. At the same time, the blank is pushed through the die cavity during operation to produce the required material.   This process is affected by the relative rotational speed between the charging and the die. The relative rotational movement of the charging and the die has an important influence on the process.   First, it will cause a large amount of shear stress, resulting in plastic deformation of the blank. Second, a large amount of heat will be generated during the relative movement between the blank and the die. Therefore, there is no need for preheating and the process is more efficient.   It can directly generate basically consolidated wires, rods, pipes and other non-circular metal geometries from various precursor charges such as metal powders, flakes, processed waste (chips or shavings) or solid blanks.   Advantages: ● No heating required. ● The generation of shear stress can improve the fatigue strength of the product. ● Any type of material can be used as a blank, making this process economical. ● Low energy input. ● Better corrosion resistance.   Disadvantages: ● Expected oxidation. ● High initial setup. ● Complex machinery.   5. Micro extrusion process: As can be understood from its name, this process involves the production of products in the sub-millimeter range.   Similar to macro extrusion, here the blank is forced through the die hole to produce the expected shape on the blank. The output can pass through a 1mm square.   Forward or direct and reverse or indirect micro extrusion are the two most basic techniques used in this era for the production of micro-components. In forward micro extrusion, the plunger drives the blank to move forward. The movement direction of the blank is the same. In reverse micro extrusion, the movement directions of the plunger and the blank are opposite. Micro extrusion is widely used in the production of absorbable and implantable medical device components, ranging from bioabsorbable stents to drug-controlled release systems. In the mechanical field, applications in manufacturing micro gears, micro pipes and other aspects can be widely observed.   Advantages: ● Very complex cross-sections can be made. ● Tiny elements can be made. ● Improved geometric tolerances.   Disadvantages: ● Manufacturing a small die and a container to meet our needs is a challenge. ● Skilled workers are required.   6. Direct or forward extrusion: In the direct extrusion process, the metal blank is first placed in a container. The container has a forming die hole. The plunger is used to push the metal blank through the die hole to make the product.   In this type, the direction of metal flow is the same as the movement direction of the plunger.   When the blank is forced to move towards the die opening, a large amount of friction will be generated between the blank surface and the container wall. Due to the existence of friction, the plunger force needs to be greatly increased, thereby consuming more power.   In this process, it is very difficult to extrude brittle metals such as tungsten and titanium alloys because they will break during this process. The tension throughout the process promotes the rapid formation of microcracks, leading to fracture.   It is difficult to extrude brittle metals such as tungsten and titanium alloys because they will break during processing. The tension causes microcracks to form rapidly, leading to fracture.   In addition, the presence of an oxide layer on the surface of the blank will aggravate friction. This oxide layer may cause defects in the extruded product.   To overcome this problem, a dummy block is placed between the gate and the working blank to help reduce friction.   Examples are pipes, cans, cups, pinions, shafts and other extruded products.   Some parts of the blank always remain at the end of each extrusion. It is called the butt. Cut it off from the product immediately at the die exit.   Advantages: ● This process can extrude longer workpieces. ● Improved mechanical properties of the material. ● Good surface finish. ● Both hot and cold extrusion are possible. ● Able to operate continuously.   Disadvantages: ● Brittle metals cannot be extruded. ● Large force and high power requirements. ● Possibility of oxidation.   7. Indirect or reverse extrusion: In this reverse extrusion process, the die remains stationary while the blank and the container move together. The die is mounted on the plunger instead of the container.   Metal flows through the die hole on the side of the plunger in the opposite direction to the movement of the plunger when the blank is compressed.   When the blank is compressed, the material will pass between the mandrels and thus through the die opening.   Since there is no relative movement between the blank and the container, no friction is recorded. Compared with direct extrusion, this improves the process and results in less plunger force being used than in direct extrusion.   To keep the die stationary, a "rod" longer than the length of the container is used. The column strength of the rod determines the final and maximum extrusion length. Since the blank moves with the container, all frictions are easily eliminated.   Advantages: ● Requires less extrusion force. ● Can extrude smaller cross-sections. ● 30% reduction in friction. ● Increase operating speed. ● Very little wear is recorded. ● Due to more consistent metal flow, extrusion defects or coarse-grained ring zones are less likely.   Disadvantages: ● The cross-section of the extruded material is limited by the size of the rod used. ● Possibility of residual stress after extrusion. ● Impurities and defects can affect the surface finish and affect the product.   8. Hydrostatic extrusion: In the hydrostatic extrusion process, the blank is surrounded by fluid in the container, and the fluid is pushed towards the blank by the forward movement of the plunger. Due to the frictionless fluid inside the container, there is very little friction at the die hole.   When filling the hole of the container, the blank will not be disturbed because it is subjected to uniform hydrostatic pressure. This successfully produces blanks with a huge length-to-diameter ratio. Even coils can be extruded perfectly or have uneven cross-sections.   The main difference between hydrostatic extrusion and direct extrusion is that there is no direct contact between the container and the blank during the hydrostatic extrusion process.   Special fluids and processes are required when working at high temperatures.   When the material is subjected to hydrostatic pressure and there is no friction, its ductility increases. Therefore, this method may be suitable for metals that are too brittle for typical extrusion methods.   This method is used for ductile metals and allows a high compression ratio.   Advantages: ● The extruded product has excellent surface polishing effect and accurate dimensions. ● There is no problem of friction. ● Minimize force requirements. ● There is no residual blank in this process. ● Uniform material flow.   Disadvantages: ● When operating at high temperatures, special liquids and procedures should be used. ● Before working, each blank must be prepared and tapered at one end. ● It is difficult to control the liquid.   9. Impact extrusion: Impact extrusion is another main method for producing metal extruded profiles. Compared with traditional extrusion processes that require high temperatures to soften materials, impact extrusion usually uses cold metal blanks. These blanks are extruded under high pressure and high efficiency.   During the traditional impact extrusion operation, a properly lubricated block is placed in the die cavity and struck by a punch in a single stroke. This causes the metal to flow back around the punch through the gap between the die and the punch.   This process is more suitable for softer materials such as lead, aluminum or tin.   This process is always performed in a cold state. The backward impact process allows very thin walls. For example, making toothpaste tubes or battery cases.   It is performed at a faster speed and with a shorter stroke. Instead of applying pressure, impact pressure is used to extrude the blank through the die. On the other hand, impact can be performed by forward or backward extrusion or a mixture of both.   Advantages: ● Significantly reduced size. ● Fast process. Processing time is reduced by up to 90%. ● Increase productivity. ● Improve tolerance integrity. ● Save up to 90% of raw materials.   Disadvantages: ● Requires very high compressive forces. ● The size of the blank is a limitation.   Factors affecting extrusion force: ● Working temperature. ● Equipment design, horizontal or vertical. ● Extrusion type. ● Extrusion ratio. ● Deformation amount. ● Friction parameters.   Extrusion process applications or uses: ● Widely used in the production of pipes and hollow pipes. And also used in the production of plastic items. ● The extrusion process is used to produce frames, doors and windows, etc. in the automotive industry. ● Metal aluminum is used for structural work in many industries.

Understanding the Power of Twin-Screw Extruders In the world of industrial manufacturing and processing, twin-screw extruders play a crucial role. These remarkable machines are at the forefront of innovation. They enable the production of a wide range of products with precision and efficiency.   What is a twin-screw extruder? At its core, it is a mechanical device that consists of two intermeshing screws rotating within a barrel. The screws work in tandem to transport, mix, and shape materials as they pass through the extruder. This process is highly versatile and can be used for a multitude of applications.   One of the key advantages of twin-screw extruders is their ability to handle a wide range of materials. Whether it's plastics, rubber, food or drugs, these extruders can handle different substances easily. The intermeshing screws provide excellent mixing and homogenization, ensuring a consistent product quality.   The design of twin-screw extruders allows precise control of temperature, pressure and screw speed. This enables manufacturers to fine-tune the extrusion process according to specific product requirements. Adjusting these parameters allows for optimal product properties and performance.   Twin-screw extruders also offer high throughput rates. This makes them ideal for high volume production. Productivity is a key factor. Continuity of extrusion also minimises downtime and maximises efficiency.   Besides industrial applications, twin-screw extruders are used in research and development. Scientists and engineers use them to explore materials and develop products. The ability to precisely control extrusion allows experimentation and optimisation of formulations.   Maintenance of twin-screw extruders is also an important aspect. Regular inspection and maintenance will provide long and reliable performance. Proper cleaning and lubrication are essential to prevent clogging and wear.   In conclusion, twin-screw extruders are powerful tools in the world of manufacturing and processing. Their versatility, precision, and high throughput make them indispensable for a wide range of industries. Whether it's producing plastic products, food items, or advanced materials, these extruders play a vital role in shaping the future of industrial production.

Assembling the screw elements in a co-rotating twin screw extruder is like assembling building blocks. It is highly flexible and customisable. To achieve optimal mixing, it’s essential to consider several factors, including material properties, feeding methods, and exhaust mechanisms. When dealing with complex material systems, matching the correct screw combination becomes vital. Each screw element performs a specific function, and different process stages require distinct combinations. The main types of screw elements include conveying, shearing, and mixing, as illustrated in Figure 1. These elements are usually classified according to their structure and characteristics. The most commonly used types are conveying elements, mixing and dispersing elements (such as toothed discs and kneading blocks) and shearing elements. Under identical operating conditions, different screw elements primarily differ in their distribution, mixing, and conveying capacities, as shown in Table 1. Conveying Elements Conveying elements can be divided into forward and reverse conveying screw elements. The key difference is that forward elements push material in the direction of extrusion, while reverse elements act against the extrusion direction. This reverse action increases material retention time in the barrel, thereby boosting filling, material pressure, and mixing efficiency. When setting conveying screw elements, several characteristics should be considered, including depth, lead, flight thickness, and clearance, as illustrated in Figure 2. The primary function of these elements is to transport material, with a shorter local residence time in the barrel. Among these characteristics, lead is the most crucial factor. The larger the lead, the higher the extrusion output, resulting in shorter material residence times, which can reduce mixing quality, as shown in Table 2. In general, large-lead screw elements are primarily used in scenarios where high throughput is emphasized, such as when dealing with heat-sensitive materials that require minimal residence time to prevent degradation. They are also used near exhaust ports to increase material surface area for effective degassing. When a balance between conveying and mixing is desired, medium-lead screw elements are typically chosen. These elements are often used in combinations where the lead gradually decreases, providing both conveying and pressurizing functions. Small-lead screw elements are primarily applied in the feed and melting zones to enhance pressure and melting efficiency, while also improving mixing and ensuring the system’s stability. This approach to assembling screw elements ensures that twin-screw extruders can handle a wide range of materials and processes, providing flexibility and efficiency in industries like plastics, pharmaceuticals, and more.

 Structure and types of twin-screw extruders The twin-screw extruder is composed of several parts such as a transmission device, a feeding device, a barrel and screws. The functions of each component are similar to those of a single-screw extruder. Its structure is shown in Figure 1. The difference from the single-screw extruder is that there are two parallel screws in the twin-screw extruder placed in a barrel with an "∞"-shaped cross-section.      Working principle of twin-screw extruders  From the perspective of motion principles, co-rotating, counter-rotating and non-meshing twin-screw extruders are different.   Close-meshing extruder. The low-speed extruder has a closely meshed screw geometry shape, in which the screw flight shape of one screw closely matches the screw flight shape of the other screw, that is, a conjugate screw shape.   a.Counter-rotating meshing twin-screw extruder The gap between the screw grooves of the closely meshed counter-rotating twin-screw extruder is very small (much smaller than that of the co-rotating twin-screw extruder), so positive conveying characteristics can be achieved.   b.Non-meshing twin-screw extruder The center distance between the two screws of the non-meshing twin-screw extruder is greater than the sum of the radii of the two screws.     Wear situation Due to the convenient opening, the wear degree of the screw elements and the inner liner of the barrel can be found at any time, so effective maintenance or replacement can be carried out. It will not be found when there is a problem with the extruded product, causing unnecessary waste.   Reduce production costs When manufacturing masterbatches, colors often need to be changed. If it is necessary to change products, the open processing area can be opened in a few minutes. In addition, the mixing process can be analyzed by observing the melt profile on the entire screw. At present, when ordinary twin-screw extruders change colors, a large amount of cleaning materials are needed for cleaning, which is time-consuming, power-consuming and wastes raw materials. The split twin-screw extruder can solve this problem. When changing colors, only a few minutes are needed to quickly open the barrel for manual cleaning, so that less or no cleaning materials are needed, saving costs.   Improve labor efficiency During equipment maintenance, ordinary twin-screw extruders often need to remove the heating and cooling systems first, and then withdraw the screw as a whole. However, the split twin-screw extruder does not need this. Just loosen a few bolts and turn the handle device of the worm gear box to lift the upper half of the barrel to open the entire barrel, and then carry out maintenance. This not only shortens the maintenance time but also reduces the labor intensity.   High torque and high speed At present, the development trend of twin-screw extruders in the world is towards high torque, high speed and low energy consumption. The effect brought by high speed is high productivity. The split twin-screw extruder belongs to this category, and its speed can reach 500 revolutions per minute. Therefore, it has unique advantages in processing high-viscosity and heat-sensitive materials.   Wide application range It has a wide range of applications and can be suitable for the processing of various materials.   High output and high quality It has other advantages of ordinary twin-screw extruders and can achieve high output, high quality and high efficiency.   Material transmission mode In a single-screw extruder, friction drag occurs in the solid conveying section and viscous drag occurs in the melt conveying section. The friction performance of solid materials and the viscosity of molten materials determine the conveying behavior. For example, if some materials have poor friction performance, if the feeding problem is not solved, it is difficult to feed the material into a single-screw extruder. In a twin-screw extruder, especially a meshing twin-screw extruder, the transmission of materials is to some extent positive displacement transmission. The degree of positive displacement depends on the closeness of the relative screw grooves of one screw to the screw flights of the other screw. The screw geometry of a closely meshed counter-rotating extruder can obtain a high degree of positive displacement conveying characteristics.   Material flow velocity field At present, the flow velocity distribution of materials in a single-screw extruder has been described quite clearly, while the flow velocity distribution of materials in a twin-screw extruder is quite complex and difficult to describe. Many researchers only analyze the flow velocity field of materials without considering the material flow in the meshing area, but these analysis results are very different from the actual situation. Because the mixing characteristics and overall behavior of a twin-screw extruder mainly depend on the leakage flow occurring in the meshing area, however, the flow situation in the meshing area is quite complex. The complex flow spectrum of materials in a twin-screw extruder shows advantages that a single-screw extruder cannot match on a macroscopic scale, such as sufficient mixing, good heat transfer, large melting capacity, strong exhaust capacity and good control of material temperature.   1.Glass fiber reinforced and flame retardant pelletizing (such as PA6, PA66, PET, PBT, PP. PC reinforced flame retardant, etc.). High filling pelletizing (such as PE, PP filled with 75% CaCO.). Heat-sensitive material pelletizing (such as PVC, XLPE cable material). Dark masterbatch (such as filled with 50% toner). Antistatic masterbatch, alloy, coloring, low filling blending and pelletizing. Cable material pelletizing (such as sheath material, insulation material). XLPE pipe material pelletizing (such as masterbatch for hot water cross-linking). Mixing and extrusion of thermosetting plastics (such as phenolic resin, epoxy resin, powder coatings). Hot melt adhesive, PU reaction extrusion and pelletizing (such as EVA hot melt adhesive, polyurethane). K resin, SBS devolatilization and pelletizing.   Straightening device One of the most common types of plastic extrusion waste is eccentricity, and various types of bending of the wire core are important reasons for generating insulation eccentricity. In sheath extrusion, scratches on the sheath surface are often caused by the bending of the cable core. Therefore, straightening devices are essential in various extrusion units. The main types of straightening devices are: drum type (divided into horizontal type and vertical type); pulley type (divided into single pulley and pulley block); capstan type, which also plays multiple roles such as dragging, straightening and stabilizing tension; pressure wheel type (divided into horizontal type and vertical type), etc.   Preheating device Cable core preheating is necessary for both insulation extrusion and sheath extrusion. For insulation layers, especially thin insulation layers, the existence of air holes cannot be allowed. The wire core can be thoroughly cleaned of surface moisture and oil stains by high-temperature preheating before extrusion. For sheath extrusion, its main function is to dry the cable core and prevent the possibility of air holes in the sheath due to the action of moisture (or the moisture of the wrapped cushion layer). Preheating can also prevent the residual internal pressure in the plastic due to sudden cooling during extrusion. In the extrusion process, preheating can eliminate the cold wire entering the high-temperature machine head and the huge temperature difference formed when it contacts the plastic at the die opening, avoid the fluctuation of the plastic temperature and thus the fluctuation of the extrusion pressure, thereby stabilizing the extrusion amount and ensuring the extrusion quality. Electric heating wire core preheating devices are all used in extrusion units, which require sufficient capacity and rapid heating to ensure high efficiency of wire core preheating and cable core drying. The preheating temperature is restricted by the payoff speed and is generally similar to the machine head temperature.   Cooling device The formed plastic extrusion layer should be cooled and shaped immediately after leaving the machine head, otherwise it will deform under the action of gravity. The cooling method is usually water cooling, and according to different water temperatures, it is divided into rapid cooling and slow cooling. Rapid cooling is direct cooling with cold water. Rapid cooling is beneficial to the shaping of the plastic extrusion layer, but for crystalline polymers, due to sudden heating and cooling, internal stress is easily remaining inside the extrusion layer structure, which may lead to cracking during use. Generally, PVC plastic layers use rapid cooling. Slow cooling is to reduce the internal stress of the product. Different temperature water is placed in sections in the cooling water tank to gradually cool and shape the product. For the extrusion of PE and PP, slow cooling is used, that is, three stages of cooling through hot water, warm water and cold water.   After 500 hours of use, there will be iron filings or other impurities worn off by gears in the reduction gearbox. Therefore, the gears should be cleaned and the lubricating oil in the reduction gearbox should be replaced.   After using it for a period of time, a comprehensive inspection of the extruder should be carried out to check the tightness of all screws.   If there is a sudden power failure during production and the main drive and heating stop, when the power supply is restored, each section of the barrel must be reheated to the specified temperature and kept warm for a period of time before the extruder can be started.   If it is found that the instrument and pointer are fully deflected, check whether the contacts of the thermocouple and other wires are in good condition.   Structural principle For the basic mechanism of the extrusion process, simply put, it is a screw rotating in the barrel and pushing the plastic forward. The screw structure is a slope or ramp wound on the central layer, and its purpose is to increase pressure to overcome greater resistance. For an extruder, there are three kinds of resistance that need to be overcome during operation: one is friction, which includes two kinds of friction between solid particles (feed) and the barrel wall and the mutual friction between them in the first few turns of the screw (feeding zone); the second is the adhesion of the melt on the barrel wall; the third is the internal flow resistance of the melt when it is pushed forward.   Temperature principle Extrudable plastics are thermoplastics that melt when heated and solidify again when cooled. Therefore, heat is needed in the extrusion process to ensure that the plastic can reach the melting temperature. So where does the heat for melting plastic come from? First of all, the feed preheating of the weighbridge and the barrel/mold heater may play a role and are very important at startup. In addition, the motor input energy, that is, the frictional heat generated in the barrel when the motor overcomes the resistance of the viscous melt and rotates the screw, is also the most important heat source for all plastics. Of course, except for small systems, low-speed screws, high melt temperature plastics and extrusion coating applications. In operation, it is important to realize that the barrel heater is actually not the main heat source. Its effect on extrusion may be smaller than we expected. The temperature of the rear barrel is more important because it affects the conveying speed of solids in the meshing or feeding. Generally speaking, except for some specific purposes (such as glazing, fluid distribution or pressure control), the die and mold temperatures should reach or be close to the temperature required by the melt.   Deceleration principle In most extruders, the change of screw speed is achieved by adjusting the motor speed. The drive motor usually rotates at full speed of about 1750 rpm, which is too fast for a screw of an extruder. If it rotates at such a high speed, too much frictional heat will be generated, and a uniformly and well-stirred melt cannot be prepared due to the short residence time of the plastic. The typical reduction ratio should be between 10:1 and 20:1. The first stage can use either gears or pulley blocks, but in the second stage, gears are preferably used and the screw is positioned at the center of the last large gear. For some slow-running machines (such as twin-screw extruders for UPVC), there may be three deceleration stages, and the maximum speed may be as low as 30 rpm or lower (ratio up to 60:1). On the other hand, some very long twin screws used for stirring can run at 600 rpm or faster, so a very low reduction rate and more deep cooling are required. If the reduction rate is mismatched with the work, too much energy will be wasted. At this time, a pulley block may need to be added between the motor and the first reduction stage that changes the maximum speed. This either increases the screw speed and even exceeds the previous limit, or reduces the maximum speed. This can increase the available energy, reduce the current value and avoid motor failure. In both cases, due to material and its cooling requirements, the output may increase.

Double-flighted screw elements, also known as double screws, are extensively utilized in modern co-rotating twin-screw compounding extruders, constituting about 70% to 100% of the elements, excluding various kneading blocks and mixing elements. These elements have an olive-shaped cross-section. The large-lead screw elements are typically used in the feeding and exhaust sections (both natural and vacuum exhaust) of the extruder, where the material is generally not fully filled. The small-lead screw elements are primarily employed to pressurize or space kneading blocks, increasing the residence time to accelerate the melting of modified materials. This results in obtaining modified finished particles with enhanced physical and mechanical properties through more efficient screw configurations. These screw elements enhance the overall efficiency and performance of twin-screw extruders, making them crucial for various industrial applications, particularly in the processing of plastics and polymers. Their design ensures optimal material handling, self-cleaning capabilities, and the production of high-quality end products.   Nanxiang Machinery is a specialized manufacturer of precision-processed threaded elements, kneading blocks, mandrels, ultra-hard screw accessories, and wear-resistant alloy steel sleeves for parallel twin-screw extruder components. The company's products are widely used in internationally renowned brands such as Coperion, Leistritz, Berstorff, KOBE, and JSW. Their applications span across the plastic industry, food industry, feed industry, pellet manufacturing industry, and pharmaceutical industry. Nanxiang has established long-term and stable cooperative relationships with large equipment manufacturers and plastic manufacturers in Shanghai, Jiangsu, Zhejiang, Guangdong, Shandong, Shaanxi, Anhui, Chongqing, and Sichuan, and has long-term partnerships with customers in India, Thailand, Malaysia, Israel, Australia, and other countries.#twin screw extruder parts #extrusion #compounding

The single-flighted screw element is primarily used in the feeding section of a twin-screw extruder to increase the storage space in each lead, thus providing greater screw free volume for faster material transfer. This element is particularly beneficial for feeding and conveying powder materials with low bulk density, compensating for decreased output in the twin-screw main unit. The screw element's cross-section is sickle-shaped, ensuring self-cleaning of the screw teeth in both axial and normal directions. Additionally, the design enhances the efficiency of material processing by reducing potential blockages and ensuring consistent material flow. By optimizing the flow and handling of materials, single-flighted screw elements contribute significantly to the overall performance and efficiency of twin-screw extruders, making them essential components in various industrial applications, particularly in plastics and polymer processing.   Nanxiang Machinery is a specialized manufacturer of precision-processed threaded elements, kneading blocks, mandrels, ultra-hard screw accessories, and wear-resistant alloy steel sleeves for parallel twin-screw extruder components. The company's products are widely used in internationally renowned brands such as Coperion, Leistritz, Berstorff, KOBE, and JSW. Their applications span across the plastic industry, food industry, feed industry, pellet manufacturing industry, and pharmaceutical industry. Nanxiang has established long-term and stable cooperative relationships with large equipment manufacturers and plastic manufacturers in Shanghai, Jiangsu, Zhejiang, Guangdong, Shandong, Shaanxi, Anhui, Chongqing, and Sichuan, and has long-term partnerships with customers in India, Thailand, Malaysia, Israel, Australia, and other countries.#twin screw extruder parts #extrusion #compounding

1. Introduction   Chengdu Nanxiang Machinery, a leader in manufacturing twin screw extruder spare parts, was tasked with producing a high-precision component for GSW, a prominent company in Japan's advanced manufacturing sector. The project aimed to deliver a component that met stringent performance criteria, including exceptional durability, high corrosion resistance, and precise mechanical performance.   2. Problem Statement   GSW required a specialized twin screw extruder component that could withstand harsh operating conditions and maintain high performance over extended periods. The challenge was to produce a part that not only met high precision standards but also provided superior durability and resistance to corrosion, critical for their specific manufacturing processes.   3. Solution Provided   Chengdu Nanxiang Machinery was entrusted with the design and production of a twin screw extruder component that incorporated advanced materials and cutting-edge technology. Our solution involved: Precision Engineering: Utilizing state-of-the-art CNC machines and advanced manufacturing techniques to achieve the exacting precision required by GSW. Durable Materials: Selecting high-grade materials with proven performance in harsh environments to ensure the component's longevity and resistance to wear. Corrosion Resistance: Applying specialized coatings and treatments to enhance the component's resistance to corrosive elements, ensuring reliable performance in challenging conditions. 4. Implementation   The production process began with close collaboration between our engineering team and GSW to ensure all specifications and performance requirements were met. Our facility's advanced automation and precision capabilities enabled us to produce the component to exacting standards. We conducted rigorous testing throughout the manufacturing process to validate performance and quality. 5. Results The completed twin screw extruder component was delivered to GSW successfully, achieving the following outcomes: High Precision: The component met all dimensional and performance specifications with exceptional accuracy. Enhanced Durability: The part demonstrated superior resistance to wear and mechanical stress, contributing to improved operational efficiency. Superior Corrosion Resistance: The specialized treatments ensured the component maintained optimal performance even in corrosive environments. GSW reported significant improvements in their extrusion processes, including reduced downtime and maintenance costs, as well as enhanced product quality.   6. Conclusion   The successful delivery of this high-precision, durable, and corrosion-resistant twin screw extruder component underscores Chengdu Nanxiang Machinery’s commitment to excellence and innovation. By meeting and exceeding GSW’s stringent requirements, we demonstrated our capability to provide tailored solutions that drive success for our clients. We look forward to future collaborations and continuing to support GSW’s operational needs with our advanced manufacturing expertise.