








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 development and application of twin screw extruders are increasingly eye-catching. Many aspects of the performance of single and twin screw extruders that dominate the extrusion industry can no longer meet the requirements of blending, filling, reinforcement, toughening and other modifications.
What is the structure of the twin screw extruder?
How does the twin screw extruder prevent material degradation?
What are the structural characteristics of the twin screw extruder?
The twin screw extruder, a unique modular screw block is designed on the screw shaft, which is broken three times within a pitch, called a mixing screw block. Corresponding to these gaps, there are three rows of mixing blocks arranged on the inner sleeve of the barrel. The pin and the screw reciprocate in the axial direction at the same time in the process of radial rotation. The twin screw extruder moves in the axial direction once every time it rotates. Due to this special movement mode and the effect of mixing and sorting screws and pins, the material is not only sheared between the mixing pins and the irregular trapezoidal mixing blocks. And it is transported back and forth. The countercurrent movement of the material adds a very useful axial mixing movement to the radial mixing. The melt is continuously cut, turned, kneaded and stretched, and the twin screw extruder regularly interrupts the simple Layered shear mixing.
Due to the simultaneous mixing in the radial and axial directions of the twin screw extruder, the mixing effect is enhanced and the best dispersion mixing and distributed mixing are ensured, so the homogenization time is short. In addition, the mutual engagement of the mixing pin and the screw block also improves the self-cleaning ability of the barrel. The twin screw extruder can ensure stable working pressure through proper screw block combination, without uncontrollable pressure and temperature fluctuations, and prevent material degradation in the barrel.
1. The main machine barrel and screw are assembled by building blocks
The barrel of the twin screw extruder is composed of multiple sets of open and closed barrels. The split barrel can be opened quickly and conveniently for easy cleaning and maintenance; the screw is composed of various mixing sleeves on the mandrel Composed of screw block and conveying screw block. The barrel and screw can be flexibly formed into an ideal form according to different types of materials and different technological requirements.
2. Unique design of gear box and swing box
The twin screw extruder realizes the axial reciprocating movement of the screw while rotating. Every time the screw rotates, it reciprocates once, and the thread is interrupted three times, thus producing a strong mixing effect. The mixing effect is in the axial direction rather than the radial direction, and occurs between the thread and the pin. All materials in the screw channel are subjected to uniform shear stress, instead of a thin layer of material being sheared.
Great products begin with the best engineering staff, and Nanjing JlEYA is ready to assist you with your technical requirements for twin screw extruder.
Nanjing Jieya is a professional manufacturer of twin screw compounding extruders since 2004. Our extruders series include SHJ series, HT series, JY series, SJ series, etc. Today we will tell you the differences between SHJ series twin screw extruders and HT series high torque twin screw extruders from three main points below:
1. Torque grade
The torque rating grade of our SHJ series twin screw extruder is T/A3≤8 while HT series is 9≤T/A3≤13.5. Our HT series adopt high torque gear box, which is suitable for customers that pursuit high efficiency machines.
2. Power transmission
SHJ series use clutch for power transmission while HT series use torque protector, for example, R+W brand, Bibby brand, etc.
3. Output
The output of HT series twin screw extruder is much higher than SHJ series.
So HT series can further improve the performance of extruders.But surely, price is higher than SHJ series.
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 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/
We hereby invite to you visit our booth in The 5th China International Plastics Exhibition.
Jieya booth: 7-200 in hall 7
Date: 2023.2.25-27
Address: Nanjing International Expo Center
See you at the exhibition!
Jieya team wish you have a nice holiday :)
(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.)
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.