The drive section of the twin screw extruder consists of 3 parts: motor, clutch, and gearbox.
The reduction and distribution gear unit reduces the motor speed to the screw shaft speed and distributes the input torque to the two output shafts. Clutch is installed between the drive motor and the gearbox drive shaft.
The processing section of the twin screw extruder in SHJ series extruder consists of individual barrel sections which are replaceable. Depending on the process tasks, reserve feed port, liquid injection port or twin screw side feed port is available.
Owing to the modular design of the twin screw extruder screw elements and screw barrels, conveying, plasticizing, homogenizing, pressure build-up and devolatilization zones can be established, depending on the process task.
For product intake and conveying, screw elements are used. The extruder can be fed with powder, pellets, chips, melt, paste, etc.
Plasticizing, mixing and dispersing are done by the twin screw extruder kneading elements. By varying the thickness of the kneading disks and their angle of stagger, their mixing, shearing and dispersing action can be adjusted to the individual requirements.
The screw elements are arranged on screw shafts. The co-rotating and closely intermeshing screw shafts have a sealing profile.
The screw barrels are supported by barrel supports. Axial displacement of the processing section resulting from thermal dilatation is absorbed by these supports.
The discharge section of the twin screw extruder consists of die head and screen changer, which is installed at the end of twin screw extruder discharging direction. There are several types of die heads and screen changers to meet the requirements of different polymers and processing technology.
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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.
The single-screw extruder has a simple design and a low price, so it is widespread and demand on the market was high.
What are the application areas and benefits of single-screw extruders?
What is the development history of the single-screw extruder?
What are the main technical parameters of the single-screw extruder?
The single-screw extruder is mainly used for extruding soft and hard polyvinyl chloride, polyethylene, and other thermoplastic. It can process a variety of plastic products such as films, tubes, plates, tapes, etc., can also be used for granulation.
The single-screw extruder is characterized by advanced design, high quality, good plasticization, and low energy consumption. It uses an evolutionary drive that is characterized by low noise development, stable operation, high load capacity, and long service life.
The single-screw extruder is one of the most important devices for the processing of plastic molding parts. It uses external energy transfer and heat transfer of external heating elements to carry out the transport of plastics solids, compaction, melting, shielding, and extrusion forms.
Since the birth of the snail extruder, it has evolved from an ordinary snail extruder to a new type of snail extruder after almost a hundred years of development. Although there are many types of new single-screw extruders, the extrusion machine is the same.
The extrusion process of the traditional snail extruder is realized by heating outside the cylinder, solid and cylinder, snail friction, and melting shear force.
"friction coefficient" and "friction force", "viscosity" and "shear tension" are the main factors influencing the performance of conventional screw extruders. The extrusion process from the machine is unstable and difficult to control, especially for some heat-sensitive plastics with poor thermal stability and high viscosity.
1. Screw diameter: refers to the diameter of the outer circle of the screw, marked with D, and the unit is millimeter (mm).
2. Proportion of screw length to diameter: refers to the ratio of the length L of the working part of the screw (the length of the threaded part, i.e. the length from the center line of the feed opening to the end of the screw) and the screw diameter D, expressed by L/D.
3. Snail speed range: refers to the highest speed of the snail up to the lowest speed of the snail; n is used to represent the speed of the snail, and the unit is revolutions per minute (U/min).
4. The power of the main screw drive engine: expressed by P, the unit is kilowatt (kW).
5. Heating performance of the extruder cylinder: expressed by E is the unit kilowatt (kV).
6. The output capacity of the extruder: expressed by Q, the unit is kilogram per hour (kg/h).
7. The height of the extruder rim: refers to the distance from the center line of the screw to the ground, expressed by H, and the unit is millimeters (mm).
8. Extruder outer dimensions: refers to total length (x) total width (x) total height expressed by L x B x H, and the unit is millimeters or meters (m m or m)
9. Extruder quality: expressed in W, the unit is kilogram or tonne (kg or t).
We can see the huge role that single-screw extruders play in the production industry, and they have become indispensable components. And Nanjing JlEYA a Chinese pioneer in single-screw extruder production,has committed to providing the most suitable single-screw extruder at a reasonable price, and whatever it takes to satisfy the customer’s needs.
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.
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.
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.
The twin screw extruder's standard equipment includes a sturdy base frame dedicated to housing the temperature control unit and oil lubrication system. The equipment features advanced control software for seamless integration into digital factories, ready for Industry 4.0, greatly improving ease of use. The following is a detailed description of the operating procedures of the twin screw extruder.
Here is the content list:
l Start up operation
l Stop the machine
Start up operation
1.Close the power main gate of the twin screw extruder.
2. Turn on the power at the operation panel: Press and hold the power button clockwise to turn and then release.
3. Set the temperature of each temperature zone: for example, a zone temperature according to the process requirements set the corresponding temperature, press the set button, and then adjust the up and down arrows to the desired temperature, press the set button.
4. Set the feeding rate: according to the process, requirements can be fed rate between 0 ~ 10 to set.
5. Set the host speed of the twin screw extruder: set the host speed between 0~30 according to the process requirements.
6. Add cooling water to the cooling tank.
7. In turn on the fan: press the operation button on the operation panel.
8. When you need to start the operation of the vacuum pump, you can start the vacuum pump.
9. Turn on the cutter switch.
1. Twin screw extruder normal stopping sequence: stop the feeder: close the vacuum line valve, open the vacuum chamber on the cover; gradually reduce the main screw speed; shut down the pelletizer and other auxiliary equipment: off the motor, each external water inlet valve.
2. Twin screw extruder emergency stop: (1) in case of an emergency need to stop the host, you can quickly press the electrical control cabinet red emergency stop button, and the host and the feed speed knob back to zero, and then the total power switch off. After eliminating the fault, you can restart the machine again in normal driving order. (2) encounter equipment automatic protection trip stop: need to set the various parameters knob to zero, and then reset the parameters, press the reset button and start the machine again.
1. The normal production of the first shift machine, be sure to first check whether the barrel, hopper seal is the original closed kind, such as changes or damage, should check the hopper, the machine inside the Jane there are no foreign objects.
2. Pay attention to the screw to start at a low speed, the air time can not exceed 3min.
3. Must pay attention to check the purity of each batch of material, do not allow any impurities mixed into the material.
4. The beginning of the material to pay attention to the first small amount, evenly added material, while paying attention to observe the current meter (torque meter) pointer changes.
For granular material, use metering to add material. When you first start to feed production, be sure to pay attention to the extruder production work overload phenomenon. After the forming die lip out of the material, and then gradually increase the screw speed as appropriate.
5. Often check the working condition of the motor carbon brush, abnormalities should be replaced or adjusted promptly.
6. The screw cleaning work is not allowed to use steel tools scraping material, the application of copper brush, shovel cleaning.
7. When the process temperature is suspected of displaying problems on the instrument, use mercury temperature, meter actual measurement of the machine Jane, and molding mold degree. Refer to the mercury temperature measured temperature, adjust the calibration instrument to show the temperature.
If you still have questions, you can consult our company. Our company's website is https://www.njjyextrusion.com/
The special refining effect and excellent performance of the single screw extruder have been proved in practice. Practice has proved that the reciprocating single-screw mixing extruder is a new type of plastic extrusion equipment. The emergence of single screw extruder provides a high-performance plastic processing equipment for the majority of users. Made a huge contribution to the development of the plastics industry.
What is the function of the single screw extruder operation screen?
What is the significance of the emergence of a single screw extruder?
What are the application fields of single screw extruder?
The operating panel is installed above the single screw extruder and can be rotated within 60 degrees for easy operation. There is a power indicator and emergency stop button on the right side of the touch screen. In an emergency, press the emergency stop button to stop immediately, which is used to protect the safety of the operator and the single screw extruder. The data recording, parameter setting, operation control and other operations of the entire instrument are all completed in this operation screen.
In the process of polymer processing, in order to give the polymer certain processing characteristics or to give the product specific use performance, it is often necessary to blend different polymers or blend the polymer with various additives and pigments. The single-screw extruder has the characteristics of uniform shearing, high dispersion, high filling, and stretching of the melt. And it combines the advantages of single and twin screw extruders. The unique working principle, coupled with a complete set of threaded components and supporting equipment, makes it more widely used. On a single screw extruder, it can achieve mixing, Mixing, plasticizing, dispersing, shearing, stretching, degassing, and granulation make the interface area of the melt flow in the machine far larger than the general shear flow.
The reciprocating single-screw mixing extruder is a new type of plastic mixing processing equipment, which is widely used in the filling, blending, modification, crosslinking, grafting, color masterbatch, functional masterbatch, and resistance of various plastics. Production of fuel masterbatch, conductive material, degradable masterbatch, reinforcement, toughening and other special plastic materials.
Blending different types of polymers to obtain brand new polymer alloys with specific uses.
Various mineral fillers are added to the polymer melt to make high-filling materials with excellent performance and low price.
Production of various glass fiber reinforced and flame retardant products, with the addition of glass fiber up to 50%.
It is suitable for the production of various cable sheathing materials, insulating materials, cross-linking materials, semiconductors, shielding materials, and conductive materials.
Production of thermoplastic elastomers and hot melt adhesives.
The single screw extruder is increasingly used in industrial production.Nanjing JlEYA has committed itself to offering the best-suited single screw extruders at a reasonable price, and all that is necessary to meet the needs of the customer.