








The engineering plastic twin screw extruder consists of a transmission device, a feed device, a barrel, and a screw. The function of each component is similar to that of a single-screw extruder. The difference to the single screw extruder is that in the engineering plastic twin screw extruder two parallel snails are arranged in the "cross-section" of the material.
What is the working principle of the engineering plastic twin screw extruder?
How do you treat a engineering plastic twin screw extruder?
Why is the cooling device particularly important when using engineering plastic twin screw extruders?
From the point of view of the principle of movement, the engineering plastic twin screw extruder distinguishes between the straight and uneven, and non-foaming types.
1. Double screw extruder of technical plastic
This type of engineering plastic twin screw extruder has a low speed and a high speed. The former is mainly used for profile extraction, while the latter is used for special polymer processing operations.
(1) Tightly machined extruder. The slow-running extruder has a closely combining screw geometry, in which the spiral antenna shape of one snail closely matches the spiral antenna shape of the other snail, i.e. the conjugated snail shape.
(2) Self-cleaning extruder. The simultaneous high-speed extruder has a closely tuned spiral shape. This type of snail can be executed with a relatively small snail split so that the snail has a closed self-cleaning effect. This type of engineering plastic twin screw extruder is called a compact self-cleaning engineering plastic twin screw extruder.
The gap between the two screw edges of the closely combining, opposing engineering plastic twin screw extruder is very small (much smaller than the gap in the evenly rotating engineering plastic twin screw extruder) so those positive conveying properties can be achieved.
2. Non-reciprocating double screw extruder of technical plastic
The axis distance between the two snails of the non-foaming engineering plastic twin screw extruder is greater than the sum of the radii of the two snails.
1. After using the engineering plastic twin screw extruder for 500 hours, iron chips or other impurities from the gears are in the gearbox. Therefore, the gears should be cleaned and the gear lubricant replaced.
2. The engineering plastic twin screw extruder should carry out a comprehensive inspection of the extruder after an operating period to check the density of all snails.
3. If the double screw extruder is suddenly switched off during production, the main drive, and the heating stops, if the power supply is restored, each section of the cylinder shall be reheated to the specified temperature and kept for a specified period, before you can start the extruder.
4. If the display and the display of the engineering plastic twin screw extruder are full, check if the contact of the thermocouple, etc. is good.
After the molded plastic extrusion layer has left the engineering plastic twin screw extruder, it should be cooled and formed immediately, otherwise, it will deform under the influence of gravity. The cooling method normally uses water cooling and is divided into quick cooling and slow cooling according to the different water temperatures. Fast cooling is the direct cooling by cold water. Rapid cooling is advantageous for the design of the extruded plastic layer, but in the case of crystalline polymers, due to sudden heat cooling, it is easy to leave internal stresses in the extruded layer structure, which leads to cracks during use. Generally PVC The plastic layer is deterred. Slow cooling should reduce the inner tension of the product. Water with different temperatures is given in the cooling water tank to gradually reduce the temperature and shape of the product. The extrusion of PE and PP takes place under slow cooling, i.e. through hot water, hot water, and cold water, which is called three-stage cooling.
Nanjing JlEYA is the leading manufacturer extruder manufacturer specializing in twin screw extrude. If you want to get more information, just go and connect them.
When the single screw extruder is in the extrusion molding process, its extruder screw is divided into 3 sections: feeding section (feeding section), melting section (compression section), metering section (homogenization section), these three sections Correspondingly, three functional areas are composed of materials: solid conveying area, material plasticizing area, and melt conveying area. Each area has different temperature requirements, and specific problems should be analyzed in detail. The temperature of the single screw extruder will be briefly introduced below.
What is the general temperature of the solid conveying zone in a single screw extruder?
What is the general temperature in the plasticizing zone of the material in a single screw extruder?
What is the general temperature of the melt conveying zone in a single screw extruder?
What is the general temperature of the solid conveying zone in a single screw extruder?
The temperature of the barrel in the solid conveying zone of the single screw extruder is generally controlled at 100~1400C. If the feeding temperature is too low, the solid conveying zone will be extended, reducing the length of the plasticizing zone and the melt conveying zone, which will cause poor plasticization of the single screw extruder product and affect product quality.
What is the general temperature in the plasticizing zone of the material in a single screw extruder?
The temperature of the material plasticizing zone in the single screw extruder is controlled at 170~1900C. Controlling the vacuum degree of this section is an important process index. If the vacuum degree is low, it will affect the exhaust effect, resulting in bubbles in the pipe, and seriously reducing the mechanical properties of the pipe. In order to make the gas inside the material easily escape, the plasticization degree of the material in this section should be controlled not to be too high, and the exhaust pipe of the single screw extruder should be cleaned frequently to avoid blockage. The vacuum degree of the barrel is generally 0.08~0.09MPa.
What is the general temperature of the melt conveying zone in a single screw extruder?
The temperature of the melt conveying zone in the single screw extruder should be slightly lower, generally 160~1800C. Increasing the screw speed in this section, reducing the head resistance and increasing the pressure in the plasticizing zone are all conducive to the improvement of the conveying rate. For heat-sensitive plastics such as PVC, the residence time should not be too long in this section. The screw speed is generally 20 ~30r/min. The head of the single screw extruder is an important part of extruded product molding. Its function is to generate a higher melt pressure and make the melt shape into a desired shape. The process parameters of each part of the single screw extruder are: die connector temperature 1650C, die temperature 1700C, 1700C, 1650C, 1800C, 1900C.
This is some information related to the use of single screw extruders. The use of single screw extruders is also closely related to the quality of its products. If you need more information, please contact Nanjing JlEYA.
Nanjing JIEYA attend Chinaplas 2021 held in Shenzhen. We sincerely welcome your visiting.
Our booth no.: 7Q25
Time: April 13-16, 2021
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Twin screw extruder is developed based on the single screw extruder, which has been widely used in the molding process of extruded products because of its good feeding performance, mixing and plasticizing performance, exhaust performance, and extrusion stability. So what are the advantages of a twin screw extruder? The following is a detailed introduction.
Here is the content list:
l Wear and tear
l Reduce production costs
l Increase output
l Improve labor efficiency
l High torque and high speed
Wear and tear
Since twin screw extruders are easy to open, the degree of wear of threaded elements and barrel bushings can be detected at any time, so that effective repair or replacement can be carried out. It is not necessary to find out only when there is a problem with the extruded product, which causes unnecessary waste.
Reduce production costs
When producing masterbatches on twin screw extruders, it's usually necessary to alter colors, and if a product amendment is critical, to open the open process space within several minutes, in addition to analyzing the mixing process by looking at the melt profile on the entire screw. The current common twin screw extruder needs to be cleared with a large amount of clearing material when changing colors, which is time consuming, power consuming, and a waste of raw material. The split twin screw extruder can solve this problem. When changing the color, it only takes a few minutes to quickly open the barrel for manual cleaning, so that no or less cleaning material can be used, saving costs.
Increase output
Twin screw snack extruders use side feeding technology to improve the integrity of the material and greatly increase production. The position and shape of the feed opening also have a great influence on feeding efficiency. With the same parameters, the output increases with an increase in the feed area. A rectangular cross section has a higher feed efficiency than a circular cross section for the same inlet area. The use of side by side twin screw feeds is also based on this consideration.
Improve labor efficiency
During equipment maintenance, ordinary twin screw extruders often have to remove the heating and cooling system before the screw can be withdrawn as a whole. In contrast, the split twin screw does not need to be opened by loosening a few bolts and turning the worm gearbox handle device to lift the upper half of the barrel, and then the entire barrel can be repaired. This shortens the maintenance time and reduces the labor intensity.
High torque and high speed
At present, the event trend of twin screw extruders within the world is to develop within the direction of high torsion, high speed, and low energy consumption, and also the impact of high speed is high productivity. The split twin screw extruder belongs to the current class, and its speed will reach and five hundred revolutions per minute. Therefore, its distinctive benefits in process high viscousness and warmth sensitive materials.
In the high speed, high torque core technology, asymmetric and symmetric high torque gearbox currently only Germany and Japan related manufacturers master the core technology, its speed can reach up to 1800 rpm or more, and domestic also master this core technology, such as Nanjing JlEYA extrusion company, is also currently one of the main choices of domestic high end material processing manufacturers, belongs to the domestic independent innovation national encouragement projects.
If you want to buy twin screw extruders, you can consider our cost effective products. We insist on the tenet of "quality first, customer first" and warmly welcome new and old customers to cooperate with us.
The company focuses on twin screw extruders, micro twin screw extruders, plastic extruders, parallel twin screw extruders, and other research and development and manufacturing as the core of the isotropic rotary twin screw mixing and extruding machine, the application range covers the mixing and modification of granulation, polymerization, deswelling, step molding, recycling, and other fields.
Nanjing Team sincerely invite you to attend The 15th China Chongqing Rubber, Plastics Industry Exhibition.
Our booth no.: S2544
Time: May 27-30, 2021
Address: Chongqing International Expo Center
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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.
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.
PVC compounding extruder is divided into RPVC pipe and SPVC pipe, RPVC pipe is easy to cut, welding, bonding, heating can be bent and therefore very easy to install and use. SPVC pipe has excellent chemical stability excellent electrical insulation and good flexibility and colorability this pipe is often used to replace rubber pipe to transport liquid and corrosive media also used as cable casing and wire insulation pipe, etc. So how do choose raw materials and the operation of PVC compounding extruder? The following is a detailed introduction
Here is the content list:
Raw material selection
Safety operating procedures
PVC compounding extruder in the production of hard pipe resin should be selected from the lower polymerization degree of SG-5 resin polymerization degree of the higher its physical and mechanical properties and heat resistance is better, but the resin liquidity is poor to bring some difficulties in processing, so generally choose viscosity of 1.7 ~ 1.8 × 10-3Pa-s SG-5 resin is appropriate. Hard pipe generally uses lead-based stabilizers whose thermal stability is good commonly used trisodium lead but its lubricity is poor usually and good lubricity of lead, barium soap type and use. Processing hard tube lubricant selection and use are very important to consider both internal lubrication to reduce intermolecular forces to reduce the viscosity of the melt are conducive to molding and to consider external lubrication to prevent the melt and hot metal adhesion to make the product surface shiny. Internal lubrication is generally used metal soap type external lubrication with low melting point wax. Filler mainly with calcium carbonate and barium barite powder calcium carbonate to make the pipe surface performance of good barium can improve the molding of the pipe easy to shape both can reduce costs but the amount of too much will affect the performance of the pipe pressure pipe and corrosion-resistant pipe is best not to add or add less filler.
1. Personnel without induction test and operation training cannot operate the extruder independently.
2. People who have poor eyesight and slow response can not be on duty to operate.
3. Before starting the machine to do a good job of environmental health around the PVC compounding extruder equipment, equipment around the pile of items not related to production.
4. Check the safety settings of the extruder before production for damage and test whether it can work effectively. Check whether the connection bolts are loose and whether the safety guards are firm.
5. Check the lubrication parts, remove the dirt, and refill the lubricant.
6. PVC compounding extruder barrel and die heating constant temperature time to ensure that the material temperature does not reach the process requirements when driving production.
7. Before starting the screw drive motor to use the hand plate support V pulley, should be flexible rotation, no blocking phenomenon; then start the lubricating oil pump work 3min before starting the screw rotation at low speed.
8. Screw airlift time should not exceed 2 ~ 3min.
9. PVC compounding extruder barrel before adding material to check the barrel, hopper, there is no foreign matter; raw materials should be free of metal, sand, and other impurities to Prevent damage to the screw.
10. The screw starts, the transmission parts work sound normal, the main motor current within the allowable rated value, before allowing the barrel to add material, adding material should first be a small amount of evenly added material.
11. When adjusting the die gap or clearing the dirty material, the operator should wear gloves and not face the barrel and die to prevent the molten material from spraying out of the die and scalding the body.
12. Extruder driving operation is not allowed to repair, and no one is allowed to do any work on the equipment at this time.
13. In case of the following phenomena, should be an emergency stop.
Bearing parts of the high temperature, lubricating oil (grease) out; motor odor, smoke, or shell temperature is too high; speed box lubricating oil temperature, smoke; transmission parts emit irregular abnormal sound; machine work produces violent vibration; screw suddenly stop rotating.
14. PVC compounding extruder equipment on the safety cover and the location of the safety alarm device is not allowed to change at will, not to mention artificially caused by the malfunction.
15. Find that the equipment leakage, oil leakage phenomenon should be timely maintenance troubleshooting, no water, oil flow around the machine.
If you have questions about how to use the PVC composite extruder, you can contact us on the official website. We are happy to answer for you.