








The single screw extruder is mainly composed of 3 parts: extrusion system, transmission system, and heating and cooling system. The following is a detailed introduction to the basic structure of the single screw extruder.
Here is the content list:
Extrusion system
Transmission system
Heating and cooling system
The main role of the extrusion system of the single-screw extruder is to melt and plasticize the polymer material to form a uniform melt, to realize the transformation from the glassy state to the viscous flow state. And in this process to establish a certain pressure, by the screw continuous extrusion delivery to the head die. Thus, the extrusion system plays an important role in the molding quality and output of the extrusion process.
The extrusion system mainly includes the feeding device, screw, and barrel, which is the most critical part of the extruder, of which the screw is the heart of the extruder, the material through the rotation of the screw in order to move in the barrel and get pressurized and part of the heat.
The drive system of a single screw extruder is usually composed of a motor, reducer, and bearing, whose role is to drive the screw and supply the torque and torque required by the screw in the extrusion process. During the extrusion process, the screw speed is required to be stable and does not change with the change of screw load to ensure the uniform quality of the product. However, in different situations, the screw is required to be able to achieve variable speed in order to achieve a machine that can adapt to the requirements of extruding different materials or products of different shapes. In most extruders, the change of screw speed is achieved by adjusting the motor speed. The drive system of the single-screw extruder is also equipped with a good lubrication system and a device for rapid braking.
The heating and cooling system of a single screw extruder consist of a heating device and cooling device, which are necessary for the extrusion process to be carried out smoothly. The heating and cooling devices must ensure that the polymer materials are melted and plasticized and the temperature conditions during the molding process meet the process requirements.
The cooling device is generally set up in the extruder barrel, screw and hopper bottom, and other parts. Barrel cooling can be water-cooled or air-cooled, air-cooled is generally used for small and medium-sized single-screw extruders; large single-screw extruders are mostly water-cooled or a combination of the two forms. The cooling device at the bottom of the hopper is mainly to strengthen the solid material conveying effect, to prevent the material particles from becoming sticky due to the heating, blocking the material mouth and thus affecting the feeding. Generally, for extruders with a screw diameter of 90mm or more and high-speed extruders, a cooling device must be installed at the bottom of the hopper.
Our company focuses on twin-screw extruders, micro twin-screw extruders, plastic extruders, parallel twin-screw extruders, and other kinds of research and development and manufacturing as the core of the isotropic rotary twin-screw compounding extruder. If you still want to know more, you can consult our company.
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.
The basic mechanism of the twin screw extrusion process is simply that a screw rotates in the barrel and pushes the plastic forward. The screw structure is a bevel or ramp wrapped around a central layer, the purpose of which is to increase the pressure to overcome the higher resistance. What do I need to pay attention to when using a twin screw extruder? The following is a detailed description.
Here is the content list:
l Structural principles
l Temperature principles
l Speed reduction principle
For the extruder, there are three kinds of resistance to overcome when working: one is friction, which contains the friction of the solid particles (feed) on the barrel wall and the mutual friction between them during the first few turns of the screw (feed area); the second is the adhesion of the melt on the barrel wall, and the third is the resistance of the internal logistics of the melt when it is pushed forward.
According to Newton's theorem, if an object is at rest in a certain direction, then the object is in a state of equilibrium balance of forces in this direction. For the circumferential movement of the screw, it is no axial motion, that is, the axial force on the screw is in equilibrium. So if the screw exerts a large forward thrust on the plastic melt, it also exerts a backward thrust on another object of the same magnitude but in the same direction. The thrust is exerted on the thrust bearing behind the feed opening. Most single screws have right hand threads, and if viewed from the back, they rotate backward, and they spin backward out of the barrel by rotational motion. In some twin screw extruders, however, the two screws rotate backward and cross each other in both barrels, so one must be right handed and one left handed, and in the case of an occluding twin screw, both screws rotate in the same direction and must therefore have the same orientation. However, in either case, there are thrust bearings that withstand backward forces and still comply with Newton's theorem.
Plastics extruded by twin screw extruders are thermoplastics, which melt when heated and solidify again when cooled. Thus, heat is needed during the extrusion process to ensure that the plastic can reach the melting temperature. So where does the heat to melt the plastic come from? First of all, the pound feed preheat and barrel/die heaters may play a role and are very important at startup. In addition, the motor feed energy, the frictional heat generated in the barrel as the motor overcomes the resistance of the viscous melt and turns the screw, is the most important heat source for all plastics, except for small systems, low speed screws, high melt temperature plastics, and extrusion coating applications. In operation, it is important to recognize that the barrel heater is not the primary heat source and that it may play a smaller role in extrusion than we might expect. The post barrel temperature is more important because it affects the rate of solids transport in the dentition or feed. In general, except for a specific purpose (such as varnishing, fluid distribution, or pressure control), the die head and die temperature should be at or near the temperature required for the melt.
In most twin screw extruders, the screw speed is varied by adjusting the motor speed. The drive motor usually turns at a full speed of about 1750 rpm, which is too fast for an extruder screw. If it turns at such a fast speed, too much frictional heat is generated and a uniform, the well mixed melt cannot be prepared because the retention time of the plastic is too short. A typical speed reduction ratio should be between 10:1 and 20:1, with either a gear or pulley set for the first stage, but with a gear and a screw positioned in the center of the last large gear for the second stage. For some slow running machines (eg. twin screws for UPVC), there may be three reduction stages and the maximum speed may be as low as 30 rpm or less (ratio up to 60:1). On the other hand, some very long twin screws for mixing can run at 600 rpm or faster, thus requiring a very low reduction rate and more deep cooling. If the reduction rate is incorrectly matched to the job, too much energy will be wasted. It may be necessary to add a pulley set between the motor and the first deceleration stage where the maximum speed is changed, which either increases the screw speed even beyond the previous limit or reduces the maximum speed. This increases the available energy, reduces the current value, and avoids motor failure, in both cases, the output may increase due to the material and its cooling needs.
If you still have questions, you can consult our company. Nanjing JlEYA is the leading professional manufacturer of twin screw extruders in China.
Today, we loaded 2x40HQ export to Vietnam.
One is SHJ-50 twin screw extruder, the other is SHJ-72 twin screw extruders. Both extruders are used for making filler masterbatch.
Nanjing Jieya is a leading manufacturer of twin screw compounding extruders with over 20 years experience. We will offer you the top quality with best price.
We warmly welcome your inquiry.
Each type of product in the plastic extruder line has its operating characteristics, and a detailed understanding of its operating characteristics is necessary to give full play to the effectiveness of the machine. The following is a detailed description of the operating procedures and maintenance methods for plastic extruders.
Here is the content list:
Operation procedures
Maintenance methods
The plastic extruder is one of the machine types, master the extruder operation points, the correct and reasonable use of a plastic extruder. The use of plastic screw extruder includes a series of links such as installation, adjustment, commissioning, operation, maintenance, and repair of the machine, and its use has the commonality of general machines, mainly in the drive motor and reduction and speed change device. However, the working system of the plastic screw extruder, the extrusion system, is unique, and special attention should be paid to its characteristics when using the plastic screw extruder. Extruder manuals generally have clear provisions for the installation, adjustment, and commissioning of the machine, here the main points of the operation, maintenance, and repair of the plastic screw extruder are briefly described as follows: in particular, to correctly grasp the structural characteristics of the screw, heating and cooling management instrumentation characteristics and assembly, the correct extrusion process conditions, the correct operation of the machine.
1.Pastic extruder equipment should be placed in a ventilated position to ensure that the heat of the motor work prolongs its life; the machine should be kept well grounded.
⒉Regularly check the tool screws, the plastic extruder after 1 hour of use, with tools to tighten the moving knife, fixed knife screws, to strengthen the fixed between the blade and the knife frame; should be regularly filled with lubricating oil to ensure the lubrication between the bearings; to ensure the sharpness of the cutting edge of the tool, should always check the tool to ensure its sharpness, to reduce unnecessary damage to other parts caused by the blunt lack of the blade; regularly check whether the belt is loose, and timely tightening.
3. Restart - Before starting the plastic extruder for the second time, the remaining debris in the machine chamber should be cleared to reduce the starting resistance. Periodically open the inertia cover and pulley cover to clear the ash outlet under the flange, which can cause the powder to enter the shaft bearing.
4. Replacement parts - When replacing knives, the clearance between the moving and fixed knives should be 0.8 MM for crushers over 20 HP and 0.5 MM for crushers under 20 HP. The thinner the recycled material is, the gap can be adjusted appropriately larger.
If you need to know more, you can consult our company. The company focused on co-rotating twin-screw compounding extruders with the core of the various R&D and manufacturing, such as a twin-screw extruder, mini twin screw extruder, plastic extruder, parallel twin-screw extruder, and so on, the application covers compounding mixing modified granulation, polymerization, devolatilization, step molding, renewable recycling, 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.
The high efficiency of the single-screw extruderis mainly reflected in high output, low energy consumption, and low manufacturing cost. In terms of function, the 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, building materials, packaging, ceramics, and other fields. So how to operate the single screw extruder? The following is a detailed introduction.
Here is the content list:
Preparation work before starting the machine
Start-up operation
Stop operation
1. For single-screw extruder extrusion production of materials, should meet the required drying requirements, if necessary, further drying.
2. According to the variety of products, size, select the head specifications, the machine will be installed in the order of the column, installed head flange, die body, mouth die, porous plate, and filter network.
3. Connect the compressed air pipe, install the core mold electric heating rod head heating ring, check the water system.
4. Adjust the gap evenly in all parts of the mouth die and check whether the centerline of the main machine and the auxiliary machine are aligned.
5. Start the single-screw extruder of each running equipment, check whether the operation is normal, and find faults in time to eliminate.
6. Turn on the electric heater, the head, body, and auxiliary machine evenly heated up, to be the temperature of each part than the normal production temperature of about 10 degrees, constant temperature of 30 ~ 60 minutes so that the machine temperature inside and outside the same.
Start-up is an important part of the production, poor control will damage the screw and head, the temperature is too high will cause plastic decomposition, the temperature is too low will damage the screw, barrel, and head. The start-up steps are as follows.
1. Start the machine at low speed, idle, check the screw for any abnormalities and motor, amperage meter current no overload phenomenon, the pressure gauge is normal. Machine idling should not be too long to prevent the screw and barrel-scraping grinding.
2. Gradually add a small amount of material, wait for the material extrusion out of the die, before the normal addition of material. Before the plastic is extruded, no one should be in front of the mouth die to prevent casualties.
3. After the plastic is extruded, it is necessary to lead the extruded material slowly on the cooling and shaping, traction equipment, and start this equipment beforehand. Then, according to the control instrument indication value and the requirements of the extruded products, each link will be properly adjusted until the extrusion operation reaches the normal state.
4. Cutting and sampling, checking whether the appearance meets the requirements, whether the size meets the standard, quickly testing the performance, and then adjusting the extrusion process according to the requirements of quality, so that the products meet the standard requirements.
1. Stop feeding, extrude the plastic in the single screw extruder and turn off the power of the barrel and head for the next operation.
2. Shut off the power of the main machine and the auxiliary machines at the same time.
3. Open the head connection flange, clean the porous plate and various parts of the head, when cleaning, should use copper rods, copper pieces, after cleaning, apply a little oil. Screw, barrel clean up, if necessary, the screw from the end of the machine out of the top, clean up after recovery, in general, available for the transition of material cleanup.
4. Extrusion of polyolefin plastics, usually in the extruder full load shutdown (with material shutdown), when the air should be prevented from entering the barrel, so as not to oxidize the material and affect the quality of the product when continuing production. For polyvinyl chloride plastics, can also stop with material, then close the material door, reduce the temperature at the head connection body (flange) 10 ~ 20 degrees, to stop the machine after the material squeeze net.
5. Close the total power and cooling water main valve.
If you still have questions, you can consult our company. Our company's website is https://www.njjyextrusion.com/
The structure of the engineering plastic twin screw extruder barrel is basically similar to that of the single-screw extruder screw barrel. From the appearance structure, the twin-screw extruder barrel is also divided into an integral barrel and a segmented barrel. The engineering plastic twin screw extruder is an upgrade of the single screw extruder, which has also greatly improved the efficiency of use.
What are the reasons why people choose engineering plastic twin screw extruder?
What is the workflow of engineering plastic twin screw extruder?
What are the essential devices in the engineering plastic twin screw extruder?
1. Improve labor efficiency
When the equipment is repaired, engineering plastic twin screw extruder only needs to loosen a few bolts, turn the worm gear box handle device to lift the upper part of the barrel to open the entire barrel, and then perform repairs. This not only shortens the maintenance time, but also reduces the labor intensity.
2. High torque and high speed
The development trend of engineering plastic twin screw extruder in the world is towards high torque, high speed, and low energy consumption. The effect of high speed is high productivity. engineering plastic twin screw extruder belongs to this category, and its speed can reach 500 rpm. Therefore, it has unique advantages in processing high-viscosity, heat-sensitive materials.
3. Wide range of applications
engineering plastic twin screw extruder has a wide range of applications and can be applied to the processing of a variety of materials
4. High output, high quality
engineering plastic twin screw extruder has other advantages of ordinary extruder, and can achieve high output, high quality and high efficiency.
The engineering plastic twin screw extruder used for profile extrusion is usually tightly meshed and rotated in different directions, although a few also use co-rotating twin screw extruders, generally operating at a relatively low screw speed, about 10 r/ min. The high-speed meshing co-rotating engineering plastic twin screw extruder is used for compounding, venting or as a continuous chemical reactor. The maximum screw speed of this type of extruder is 300-600r/min. Non-intermeshing extruder is used for mixing, venting and chemical reaction. Its conveying mechanism is quite different from intermeshing extruder, which is closer to the conveying mechanism of single screw extruder, although there are essential differences between the two.
Among the straightening devices used in engineering plastic twin screw extruder, the most common one is eccentric, and various types of bending of the core are one of the important reasons for the insulation eccentricity. In sheath extrusion, scratches on the sheath surface are often caused by the bending of the cable core. Therefore, the straightening device in various engineering plastic twin screw extruder is indispensable. The main types of straightening devices are: drum type (divided into horizontal and vertical); pulley type (divided into single pulley and pulley block); winch type, which has multiple functions such as dragging, straightening, and tension stabilization; Press wheel type (divided into horizontal type and vertical type), etc.
The engineering plastic twin screw extruders are used more and more widely in daily life, but its quality has a great influence on the experience of use. Nanjing JlEYA has focused on the production and development of engineering plastic twin screw extruders for more than several years, and they have always put the needs of customers as their top priority.