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(Nanjing Jieya is a professional manufacturer of twin screw compounding extruders with 20+ years experience and competitive price. We look forward to receive your inquiry.)
A twin screw extruder is composed of several parts such as a transmission device, feeding device, barrel, and screw, etc. The role of each part is similar to that of the single screw extruder. So what are the main differences between the twin screw extruder and single screw extruder? The following is the detailed introduction
Here is the content list:
l Cross sectional profile
l The way of material transfer
l The material flow velocity field
The difference from the single screw extruder is that the twin screw extruder has two parallel screws in an "∞" shaped cross section. Twin screw extruders for profile extrusion are usually closely meshed and heterogeneously rotating, although a few also use co rotating twin screw extruders, which generally operate at relatively low screw speeds of about 10 r/min. High speed meshing co rotating twin screw extruders are used for blending, venting, or as continuous chemical reactors, with maximum screw speeds ranging from 300 600 r/min. Non engaging extruders are used for mixing, venting, and chemical reactions, and their conveyors are very different from those of engaging extruders, and are closer to those of single screw extruders, although they are fundamentally different.
In the single screw extruder, the solid conveying section is friction dragging and the melt conveying section is viscous dragging. The frictional properties of solid materials and the viscosity of molten materials determine the conveying behavior. If some materials have poor frictional properties, it is more difficult to transfer the material to the single screw extruder if the feeding problem is not solved. In twin screw extruders, especially meshing twin screw extruders, the material transfer is to some extent a positive displacement transfer, the degree of positive displacement depending on the proximity of the screw prongs of one screw to the relative screw grooves of the other screw. The screw geometry of a closely meshed anisotropic rotary extruder yields a high degree of positive displacement transport characteristics.
The flow velocity distribution of the material in a single screw extruder has been described fairly well, whereas the flow velocity distribution of the material in a twin screw extruder is quite complex and difficult to describe. Many researchers have analyzed the velocity field of the material without considering the material flow in the engagement zone, but the results of these analyses are very different from the actual situation. This is because the mixing characteristics and overall behavior of a twin screw extruder depend mainly on the leakage flow that occurs in the engagement zone, yet the flow in the engagement zone is quite complex. The complex flow spectrum of the material in a twin screw extruder exhibits macroscopic advantages that cannot be matched by a single screw extruder, such as adequate mixing, good heat transfer, high melting capacity, good venting capacity, and good control of the material temperature.
If you want to know more, you can consult our company. Nanjing JlEYA is the leading manufacturer extruder manufacturer specializing in a twin screw extruder, mini twin screw extruder, plastic extruder, and parallel twin screw extruder in China, which is widely used in compounding, modification, polymerization, devolatilization, reaction, recycling, etc. After 17 years of development, now we have a 20,000 square meters workshop with annual sales of over 300+ sets, export over 60 countries.
JIEYA has the most experienced technical core team, with extensive experience in system integration of the development manufacturing, materials processing, application technology, and other fields.
The twin screw extrudernot only has the characteristics of a single-screw extruder, but also has the advantages of convenient feeding, stable extrusion, and convenient exhaust. It is widely used in the production and processing of extruded products.
Why are twin screw extruders warmly welcomed now?
Choose a single-screw extruder or a twin screw extruder?
What are the technical points of the twin screw extruder?
Why are twin screw extruders warmly welcomed now?
The twin screw extruder can not only add more ingredients to the company's products, but also can choose to quickly complete the manufacturing. Considering that "new crown pneumonia" has put every industry into trouble, the market has been looking for a quick turnaround to pay for healthy food. In addition, you may need to make up for the loss of production and sales or increase production and sales based on the current situation. Twin-screw extension can help you, and considering the lower cost and higher production and sales, it can bring more profits.
Choose a single-screw extruder or a twin screw extruder?
The single-screw extruder is used for extrusion processing technology and equipment, and the particle raw materials stay in the extruder for a long time. This means that a single-screw extruder requires a longer period than a twin screw extruder to produce the products required by the enterprise. In addition, the twin screw extruder allows you to better control the complex operation process and actual operation. As everyone knows, these controls are much more complicated. This is very important for foods that need to be mixed and mixed. The production and manufacturing facilities are complete, and the actual effect of twin-screw extrusion is the best. For polymer materials, twin-screw extrusion is also particularly effective. Considering that the design concept of twin screw extruder has a relatively large flexibility, it can be used in many industries for very specific operation processes.
What are the technical points of the twin screw extruder?
In the extrusion process of the twin screw extruder, the material is transformed from the glass state to the molten state. In addition to the balance between the heat required for plasticization of the material and the amount of heat supplied, the material is melted. Pressure is also a very important control indicator. Because the material is affected by the compression ratio of each section of the die resistance screw during the extrusion process, it does not exist under normal pressure. For different die, the compression ratio of each section of the screw is basically constant and immutable. Under the premise of the same extrusion speed, increase or decrease the feed rate, the volume of the screw material in the feeding section will change, and the volume of the material in the exhaust section will remain unchanged, so the compression section of the feeding section changes with the compression ratio, and its melt pressure follows Increase or decrease; under the premise of the same feed rate, increase or decrease the extrusion rate, the volume of the screw material in the feeding section will also change. The volume of the material in the exhaust section remains unchanged, so the compression section of the feed section changes with the compression ratio, and its melt pressure increases or decreases accordingly; the feed speed increases or decreases simultaneously with the extrusion speed, because the volume of the screw material in the feed section remains unchanged , Only due to the increase or decrease of the speed, the melt pressure change.
Due to different fields and different types of twin screw extruder, they are widely used in many industries. To meet these growing demands, Nanjing JlEYA has committed to providing the increasing of twin screw extruder.
Twin-screw extruders have barrels with an extension range of 4 and 6D, allowing for precise process design to meet specific customer requirements. All barrels allow for precise temperature control. Cooling is achieved by cooling water injection and high-performance electric heating rods for direct and fast heating. The auxiliary equipment of the twin-screw extruder consists of a straightening device, a preheating device, and a cooling and heating device. The following is a detailed description of the auxiliary equipment.
Here is the content list:
l Straightening device
l Preheating device
l Cooling device
One of the most common types of plastic extrusion rejects is eccentricity, and bending of the wire core in various patterns is one of the most important causes of insulation eccentricity. In sheath extrusion, scratches on the sheath surface are also often caused by the bending of the cable core. Therefore, a variety of extrusion units in the straightening device is essential. The main types of straightening devices are roller type (divided into horizontal and vertical type); pulley type (divided into single pulley and pulley group); stranded pulley type, which plays a variety of roles such as dragging, straightening, and stabilizing tension; pressure pulley type (divided into horizontal and vertical type), etc.
Cable core preheating is necessary for both insulation extrusion and sheath extrusion. For the insulation layer, especially the thin layer of insulation, the existence of pores should not be allowed, the core can be completely removed from the surface of the water, oil, and dirt through high temperature preheating before extrusion. For the sheath extrusion, the main role is to dry the cable core, to prevent the role of moisture (or moisture around the bedding layer) to make the sheath in the possibility of porosity. Preheating can also prevent the plastic from being extruded due to sudden cooling and residual internal pressure. In the process of extruding plastic, preheating can eliminate the cold line into the high-temperature heat, in contact with the plastic at the mouth of the die to form a disparity in temperature, to avoid fluctuations in plastic temperature and lead to fluctuations in extrusion pressure, to stabilize the amount of extrusion and ensure the quality of extrusion. Extrusion unit is used in the electric heating core preheating device, requires sufficient capacity, and ensures rapid temperature rise, so that the core preheating and cable core drying efficiency. The preheating temperature is restricted by the speed of wire release, generally similar to the temperature of the head.
The formed plastic extrusion layer after leaving the head should be immediately cooled and shaped, otherwise, deformation will occur under the action of gravity. The way of cooling usually uses water cooling, and according to the water temperature is different, divided into rapid cooling and slow cooling. Rapid cooling is the direct cooling of cold water, rapid cooling of plastic extrusion layer sizing is beneficial, but for crystalline polymers, due to sudden heat cooling, easy to internal residual stress in the extrusion layer organization, resulting in the use of the process of cracking, general PVC plastic layer using rapid cooling. Slow cooling is to reduce the internal stress of the product, in the cooling water tank placed in sections of different temperatures of water, so that the product gradually cool down and set, PE, PP extrusion on the use of slow cooling, that is, after hot water, warm water, cold water three cooling.
If you are engaged in a twin-screw extruder-related industry, you can consider our cost-effective products.
underwater pelletizing machine is similar to airflow granulator and water jet granulator. The equipment part mainly covers: plastic granulator, single and twin screw plastic extruder, plastic film blowing machine, bag making machine, printing machine, coating machine, Adhesive tape machine, tape slitting machine, slitting machine, strapping machine.
What is the problem of uneven pelletizing by the underwater pelletizing machine?
What is the workflow of the underwater pelletizing machine?
What is the technological advantages of the underwater pelletizing machine?
1. underwater pelletizing machine, the machine head is not evenly heated, and the machine head temperature is stable before starting up;
2. The cooling water of the underwater pelletizing machine is boiled prematurely, and the water should be boiled when the machine head starts to discharge;
3. It is also possible that there is a problem with the hot runner design of the machine head, which is caused by uneven pressure.
Before being made into final products, most polymers must be blended and then pelletized to become marketable raw materials. The power required by the underwater pelletizing machine is directly proportional to the extrusion volume and exponentially related to the size of the filter screen. There are many different types of pelletizer designs, but all pelletizers have some common places, and they can be divided into two categories: cold pelletizing system and die face hot pelletizing system. The main difference between the two categories is the time arrangement of the pelletizing process. The cold pelletizing system cuts pellets from the solidified polymer at the end of the process; while in the die-face hot pelletizing system, pellets are cut when the molten polymer emerges from the die, and pellets are processed downstream cool down.
The underwater pelletizing machine treated by standard process has the following significant advantages:
The appearance standard of the products produced by the underwater pelletizing machine is exquisite and bright;
2. The hardness of the wear layer in contact with the material by the underwater pelletizing machine can reach HV 600-800, and the local hardness can reach HV900-1100. The hardness is increased to 2-4 times the original hardness. Compared with the non-standard machine without heat treatment, it is resistant to The wear performance is increased by 3-5 times;
3. The products of the underwater pelletizing machine are not deformed after long-term use, effectively avoiding the screw breaking due to the excessive wear of the barrel, and the stable service life is 2-3 times that of the traditional machine, which greatly reduces the investor's investment in replacement parts;
4. The wear-resistant layer of the barrel screw produced by the underwater pelletizing machine has high hardness, while the base material still retains good toughness and processing performance;
5. The service life of the screw of the underwater pelletizing machine has increased from the hundred-ton level of the ordinary plastic pelletizing machine to the thousand-ton level.
Nanjing JlEYA has focused on the production and development of underwater pelletizing machines for several years, and they have always put the needs of customers as their top priority. Here, you can choose the underwater pelletizing machine that suits your need.
The single screw extruder is a special reduction power device designed for plastic and rubber single screw extruder equipment. The reducer is matched with the motor. The gear parts are made of high-strength alloy steel. The gears are processed by carburizing, quenching, and high-precision gear grinding. The gear accuracy is level 6, and the tooth surface hardness is HRC58-62.
What is the principle of single screw extruder?
What is the current industry development of single screw extruder?
What should I pay attention to when using single screw extruder?
The single screw extruder is generally divided into three sections in effective length. The effective length of the three sections is determined according to the diameter of the screw and the pitch and depth of the screw, which are generally divided into one-third of each; the last thread of the single screw extruder has been called the conveying section. It is required that it cannot be plasticized, but it must be preheated and compressed;
The second section of the single screw extruder is called the compression section. At this time, the volume of the screw groove gradually decreases, and the temperature must reach the degree of plasticization of the material. The compression produced here is from the conveying section three, and here it is compressed to one. Some machines also have Change, the plasticized material enters the third stage;
The third section of the single screw extruder is the metering section, where the material maintains the plasticizing temperature to supply the machine head, which is generally slightly higher than the plasticizing temperature.
In single screw extruder equipment, the plastic extruder is normally referred to as the main machine and the following equipment, the plastic extruder, is referred to as the auxiliary machine. After more than 100 years of development, the plastic extruder has been derived from the original single-screw extruder, a variety of models such as double-screw, multi-screw and even non-screw models have been derived. The plastic extruder (host) can be used with different plastic moulding machines such as tube, foil, holding material, monofilament, flat wire, strapping, extruding network, plate material, profile material, pelleting, cable coating, etc. are used. Suitable for different plastic extrusion production lines for the production of different plastic products. Therefore, plastic extrusion machines are today and in the future one of the most common models in the plastics processing industry.
What should I pay attention to when using single screw extruder?
(1) The material convey way of the single screw extruder mainly relies on friction, which limits its feeding performance. And it is difficult to add the powder, paste, glass fiber and inorganic fillers, so pay attention to the material used.
(2) When the pressure of the single screw extruder head is high, the reverse flow will increase and the productivity will decrease. Therefore, always pay attention to the pressure of the equipment.
(3) The surface renewal effect of the single screw extruder material in the exhaust zone is small, so the exhaust effect is poor.
(4) single screw extruder is not suitable for certain processes, such as polymer coloring, thermosetting powder processing, etc.
The single screw extruder has achieved an irreplaceable position in industrial production. Nanjing JlEYA is committed to providing various bending and rolling machines of high quality for all customers from all over the world.
In plastic extrusion molding equipment, the plastic extruder is usually called the main machine, while its subsequent equipment plastic extrusion molding machine is called the auxiliary machine. Plastic extruders can produce a variety of plastic products. Therefore, the plastic extrusion molding machine is one of the widely used machines in the plastics processing industry, both now and in the future. So what are the characteristics of plastic extruders? The following is a detailed introduction.
Here is the content list:
Modularity and specialization
High efficiency and multi-functionalization
Enlargement and precision
Intelligent and networked
The modular production of plastic extruders can adapt to the special requirements of different users, shorten the research and development cycle of new products, and strive for a larger market share; while specialized production can arrange the production of each system module component of extrusion molding equipment at a fixed point or even for global procurement, which is very beneficial to ensure the quality of the whole period, reduce costs and accelerate the capital turnover.
The high efficiency of plastic extruders is mainly reflected in the high output, low energy consumption, and low manufacturing cost. In terms of function, the screw plastic extruder has been used not only for extrusion molding and mixing processing of polymer materials but its use has been broadened to food, feed, electrode, explosives, building materials, packaging, pulp, ceramics, and other fields.
Achieving the large-scale plastic extruder can reduce the production cost, which is a more obvious advantage in the large twin-screw plastic pelletizing set, film blowing set, pipe extrusion set, etc. National key construction services required for major technical equipment, large-scale ethylene project supporting one of the three key equipment of large extrusion pelletizing unit long-term dependence on imports, so we must accelerate the localization process to meet the development needs of the petrochemical industry.
Plastic extruders in developed countries have generally used modern electronic and computer control technology, the entire extrusion process parameters such as melt pressure and temperature, the temperature of each section of the body, the main screw and feeding screw speed, feeding volume, the ratio of various raw materials, motor current and voltage and other parameters for online detection, and the use of microcomputer closed-loop control. This is extremely beneficial to ensure the stability of process conditions and improve the precision of products.
If you need to buy a plastic extruder, you can consider our cost-effective products. Nanjing JlEYA is the leading manufacturer extruder manufacturer specializing in a twin-screw extruder, mini twin screw extruder, plastic extruder, and parallel twin-screw extruder in China, which is widely used in compounding, modification, polymerization, devolatilization, reaction, recycling, etc. After 17 years of development, now we have a 20,000 square meters workshop with annual sales of over 300+ sets, export over 60 countries.
JIEYA has the most experienced technical core team, with extensive experience in system integration of the development manufacturing, materials processing, application technology, and other fields.