








A single-screw extruder consists of an Archimedes screw rotating in a heated barrel. It is widely used because of its simple structure, easy manufacturing, high processing efficiency, and low price, and is the most technically mature and used type of extruder at present. The following is a detailed introduction to single-screw extruders.
Here is the content list:
The design concept of a single-screw extruder
Single-screw extruder features
Uses of single screw extruder
(1) Single-screw extruders are high-speed, high-output extrusions based on high quality, and the design concept of low-temperature plasticization ensures the extrusion of high-quality products. Two-step overall design to strengthen the plasticizing function and ensure the adjustment of high-performance extrusion.
(2) A special barrier of the single-screw extruder, integrated mixing design to ensure material mixing effect and high torque output, extra-large thrust bearing.
(3) The gears and shafts of a single screw extruder are high-strength alloy steel, carburized, ground teeth treatment, high hardness, high finish, and ultra-low noise. PLC intelligent control, the linkage between main and auxiliary machines is possible.
(4) Single screw extruder easy to monitor human-machine interface, easy to understand the processing and machine status, and the control method (temperature control instrument) can be changed as needed.
(5) The material of the single screw extruder is 38CrMoAL/A nitride treatment, which is wear-resistant. It has a combination of air-cooled and water-cooled cooling for strict temperature precision control, and the unique air inlet design makes it a perfect water-cooling device.
(6)Single screw extruder with grooved surface feeding bottom sleeve of screw barrel has enhanced feeding function, which provides a guarantee for high speed and high output extrusion.
1. Hard gearbox, AC or DC stepless drive speed regulation.
2. New screw structure, melt and mix uniformly to ensure low melt temperature and high output
3. Screw barrel material adopts nitride steel 38CrMoAIA nitride treatment, and the surface alloy treatment has higher hardness.
4. Cast copper, cast aluminum heater, air-cooled and water-cooled according to requirements.
5. Advanced electrical control system of single screw
Pipe extrusion of single-screw extruder: it is suitable for PP-R pipe, PE gas pipe, PEX cross-linked pipe, aluminum-plastic composite pipe, ABS pipe, PVC pipe, HDPE silicon core pipe, and various co-extruded composite pipes.
Sheet and plate extrusion: applicable to PVC, PET, PS, PP, PC, and other profiles and plates extrusion. Extrusion of various other plastics such as silk, rod, etc.
Profile extrusion: adjusting the extruder speed and changing the structure of the extrusion screw can be applied to the production of various plastic profiles such as PVC, polyolefin, etc. Modified pelletizing: It is suitable for blending, modifying, and enhancing pelletizing of various plastics.
Nanjing JlEYA is a leading extruder manufacturer specializing in a twin-screw extruder, micro twin-screw extruder, plastic extruder, and parallel twin-screw extruder, which are widely used in compounding, modification, polymerization, devolatilization, reaction, recycling, and other fields. After 17 years of development for many years, now we have a 20,000 square meters plant, 300+ sets of annual sales, and export to more than 60 countries.
The Underwater pelletizing machine cuts pellets on the plastic steel ejection surface without centrifugal action to eject them, but direct water pressure flows through the nozzle surface to drain.
What is contained in the extrusion system of the Underwater pelletizing machine?
What is the use of the Underwater pelletizing machine?
What are the causes and solutions for the high melting of the Underwater pelletizing machine?
The extrusion system includes a snail, a cylinder, a funnel, a nozzle, and a nozzle. Through the extrusion system, the plastic is plasticized into a uniform melt and continuously extruded by the screw under the resulting pressure.
(1) Screw: It is the most important part of the Underwater pelletizing machine. It is directly related to the scope and productivity of the extruder. It consists of high-strength corrosion-resistant alloy steel.
(2) Cylinders: The cylinder is a metal cylinder that is generally made of alloy steel or composite steel tubes clad with alloy steel, heat resistant, high-pressure resistant, strong, wear-resistant, and corrosion-resistant. The cylinder and the screw are matched to each other to realize the crushing, grinding, melting, plasticization, suction, and compaction of the plastic as well as the continuous and uniform supply of the rubber material to the molding system. In general, the barrel length of an Underwater pelletizing machine is 15-30-fold its diameter, so that the plastic is completely heated and plasticized.
Underwater pelletizing machines can be used for chemical fertilizers, white soot, inorganic salts, chlorinated isocyanic acid, bleaching powder, pesticides, oxides, etc. as well as for industrial recycling dust: such as cast iron dust, lead, zinc, aluminum dust, converter dust, filter dust, grinding dust, etc. The material is forced to be pressed and molded by mechanical pressure without adding a net, and the purity of the product is guaranteed. The process process process is short, energy consumption is low, and performance high. The dry powder is directly granulated without a subsequent drying process, which is more conducive to the connection and transformation of the existing production process. The granular strength is high and the increase in bulk density is more significant than in other granulation processes. The Underwater pelletizing machine is particularly suitable for occasions to increase the specific weight of the product collection. The operating flexibility is great, the range of applications is wide and the crushing force can be adjusted by hydraulic pressure.
Causes analysis: high filter masks, low melting index of polypropylene powder and high feed volume, low temperature of each section of the Underwater pelletizing machine results in the material being incompletely melted, and a low opening rate of the template impede the extrusion of the nozzle head material, etc. The reasons may cause the melting pressure to be too high.
Solution: If the Underwater pelletizing machine produces products with a low melting index, a filter with a low mesh width should be used and the throttle opening should be enlarged to reduce backpressure; the filter should be replaced in time and the quality of different additives and polypropylene powder should be monitored. Contains medium ash. Reduce the feed load. Without compromising the quality of the extruded product, increase the temperature of each section of the cylinder to increase the temperature of the polypropylene melt and increase the flow capacity of the material. After the extruder has been stopped, increase the temperature of the head of the Underwater pelletizing machine and keep it at a constant temperature for a while and rinse and then thoroughly clean the template.
The underwater pelletizing machine have been used in many fields Nanjing JlEYA maintains close relationships with customers in underwater pelletizing machine industry, and is committed to strengthening production and operation, improving quality and safety.
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.
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.
PVC compounding extruder is divided into two types of hard and soft RPVC pipes, RPVC pipes are chemically resistant and insulating, mainly transporting various fluids and used as wire sleeves, etc. SPVC pipes are manufactured by extruding PVC resin with a large amount of plasticizer and a certain amount of stabilizer and other additives after granulation. The following is a detailed description of the equipment functions of the PVC compounding extruder.
Here is the content list:
High Speed Mixer High-Speed Mixing
Accurate matching of feeding device
Water tank for pipe forming
Traction machine frequency conversion speed control
Automatic cutting
Unloading the material from the turning frame
Raw material intermixture is to feature PVC stabilizer, softener, inhibitor, and different auxiliary materials to the high-speed mixer in proportion and sequence to the method.
The PVC compounding extruder part is equipped with a quantitative feeding device to match the extrusion volume with the feeding volume to ensure stable extrusion of products. Due to the characteristics of the conical screw, the feeding section has a larger diameter, and the heat transfer area and sheer speed of the material are larger, which is contributive to the plasticization of the fabric and also the little diameter of the screw within the metering section reduces the warmth transfer space and also the sheer speed of the soften so that the melt can be extruded at a lower temperature. When the screw rotates in the barrel, the PVC mixture is plasticized and pushed to the head to achieve compaction, melting, mixing, and homogenization and to achieve the purpose of exhaust and dehydration. The feeding device and screw drive device adopt frequency conversion to realize synchronous speed regulation.
PVC compounding extruder dies head part of the compacted, molten, blended, and homogenized PVC has subsequent materials through the screw to the die head extrusion die head is the key component of pipe forming.
The vacuum shaping water tank of PVC compounding extruderis used for pipe shaping and cooling, the vacuum shaping water tank is equipped with vacuum system for shaping and cooling and water circulation system stainless steel box body circulating water spray cooling, the vacuum shaping water tank is equipped with front and rear moving device and left and right, high and low adjustment manual device.
The traction machine is used to continuously and automatically lead the cooled and hardened pipe from the head with frequency control.
The cutting machine is controlled by the travel switch according to the required length and then automatically cut and delay the turning frame to implement the flow of production, the cutting machine with a fixed-length work switch signal as a command to complete the whole process of cutting in the cutting process and pipe running synchronization cutting process is completed by electric and pneumatic drive, the cutting machine is equipped with a dust suction device to suck out the cutting debris and recycling.
Unloading the material from the turning frame
The material turning action is controlled by the cylinder through the air circuit to achieve the material turning frame is equipped with a limit device when the cutting saw cut off the pipe after the pipe continues to transport after a delay, the cylinder into the work of turning action to achieve the purpose of unloading. After unloading, it will be automatically reset after a delay of several seconds to wait for the next cycle.
Nanjing JlEYA is the leading manufacturer extruder manufacturer specializing in 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 development, now we have 20,000 square meters workshop with annual sales 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 andother fields.
underwater pelletizing machine is similar to airflow granulator and water jet granulator. The equipment part mainly covers: plastic granulator, single and twin screw plastic extruder, plastic film blowing machine, bag making machine, printing machine, coating machine, Adhesive tape machine, tape slitting machine, slitting machine, strapping machine.
What is the problem of uneven pelletizing by the underwater pelletizing machine?
What is the workflow of the underwater pelletizing machine?
What is the technological advantages of the underwater pelletizing machine?
1. underwater pelletizing machine, the machine head is not evenly heated, and the machine head temperature is stable before starting up;
2. The cooling water of the underwater pelletizing machine is boiled prematurely, and the water should be boiled when the machine head starts to discharge;
3. It is also possible that there is a problem with the hot runner design of the machine head, which is caused by uneven pressure.
Before being made into final products, most polymers must be blended and then pelletized to become marketable raw materials. The power required by the underwater pelletizing machine is directly proportional to the extrusion volume and exponentially related to the size of the filter screen. There are many different types of pelletizer designs, but all pelletizers have some common places, and they can be divided into two categories: cold pelletizing system and die face hot pelletizing system. The main difference between the two categories is the time arrangement of the pelletizing process. The cold pelletizing system cuts pellets from the solidified polymer at the end of the process; while in the die-face hot pelletizing system, pellets are cut when the molten polymer emerges from the die, and pellets are processed downstream cool down.
The underwater pelletizing machine treated by standard process has the following significant advantages:
The appearance standard of the products produced by the underwater pelletizing machine is exquisite and bright;
2. The hardness of the wear layer in contact with the material by the underwater pelletizing machine can reach HV 600-800, and the local hardness can reach HV900-1100. The hardness is increased to 2-4 times the original hardness. Compared with the non-standard machine without heat treatment, it is resistant to The wear performance is increased by 3-5 times;
3. The products of the underwater pelletizing machine are not deformed after long-term use, effectively avoiding the screw breaking due to the excessive wear of the barrel, and the stable service life is 2-3 times that of the traditional machine, which greatly reduces the investor's investment in replacement parts;
4. The wear-resistant layer of the barrel screw produced by the underwater pelletizing machine has high hardness, while the base material still retains good toughness and processing performance;
5. The service life of the screw of the underwater pelletizing machine has increased from the hundred-ton level of the ordinary plastic pelletizing machine to the thousand-ton level.
Nanjing JlEYA has focused on the production and development of underwater pelletizing machines for several years, and they have always put the needs of customers as their top priority. Here, you can choose the underwater pelletizing machine that suits your need.
Material delivery method
In a single-screw extruder, there is friction drag in the solids conveying section and viscous drag in the melt conveying section. The friction properties of the solid material and the viscosity of the molten material determine the conveying behavior. If some materials have poor friction properties, if the feeding problem is not solved, it will be difficult to feed the materials into the single-screw extruder. In twin-screw extruders, especially intermeshing twin-screw extruders, the conveying of materials is to some extent forward displacement transmission, and the degree of forward displacement depends on the relationship between the flight of one screw and that of the other screw. the proximity of the relative screw grooves. The screw geometry of the closely intermeshing counter-rotating extruder results in a high degree of positive displacement delivery characteristics.
Material flow velocity field
At present, the flow velocity distribution of the material in the single-screw extruder has been described quite clearly, while the flow velocity distribution of the material in the twin-screw extruder is quite complicated and difficult to describe. Many researchers just do not consider the material flow in the meshing area to analyze the flow velocity field of the material, but these analysis results are very different from the actual situation. Because the mixing characteristics and overall behavior of a twin-screw extruder are primarily determined by the leakage flow that occurs in the intermeshing zone, the flow situation in the intermeshing zone is quite complex. The complex flow spectrum of the material in the twin-screw extruder shows macroscopic advantages that the single-screw extruder cannot match, such as sufficient mixing, good heat transfer, large melting capacity, strong exhaust capacity and good temperature control of the material, etc.