








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.
In terms of the principle of motion, there are different types of twin-screw extruderswith isotropic and anisotropic meshing and non-meshing types. So what are the types of twin-screw extruders? And what are the application areas? The following is a detailed introduction.
Here is the content list:
l Isotropic twin-screw extruder
l Anisotropic twin-screw extruder
l Non-Engaging Twin-Screw Extruders
l SHJ-20 twin-screw laboratory extruder
l Application areas
These extruders are available at low and high speeds, the former mainly for profile extrusion, while the latter is used for special polymer processing operations.
(1) Close-meshing extruder. Low-speed extruders have a closely meshed screw geometry, where the profile of one screw is closely matched to the profile of the other screw, i.e., a conjugate screw profile.
(2) Self-cleaning extruder. High-speed co-rotating extruders have a closely matched screw-prong profile. This screw can be designed to have a fairly small screw gap so that the screw has a closed self-cleaning effect, this twin-screw extruder is called a tight self-cleaning co-rotating twin-screw extruder.
The tightly meshed anisotropic twin-screw extruder has a small gap between the two screw grooves (much smaller than that in a co-engaged twin-screw extruder) so that a positive conveying characteristic can be achieved.
The center distance between the two screws of a non-engaging twin-screw extruder is greater than the sum of the radii of the two screws.
It is suitable for universities, colleges, and scientific research laboratories for process and formula development, etc. It has the features of beautiful appearance, compact structure, easy to use and maintain, and precise control of process conditions. Gearbox homemade torque level: T/A3≤8 national standard main parts, twin-screw extruder new structure design, and hardened gear teeth of high precision grinding, to ensure that the gearbox works efficiently for a long time. Screw self-made: Screw elements with tightly meshed design, block type, can be easily replaced to suit different materials. Barrel captive: The precision grade of the twin-screw extruder can reach T6, favorable to energy saving, and the block type design makes various combinations possible.
The two main areas of application of twin-screw extruders are extrusion of thermosensitive materials such as PVC pipes and profiles and processing of special polymers such as blending, venting, chemical reactions, etc. Twin-screw extruders for profile extrusion have intermeshing screw ribs and grooves and operate at a low speed of about 10/min or less. Compared to single screws, twin-screw extruders have much better feeding and conveying performance, especially for those difficult to feed and easy to slip, such as fibrous, powdery, and greasy materials. The short and uniform material retention time, better mixing, and larger heat transfer area allow for good material temperature control, which is especially important for processing heat-sensitive materials.
If you want to buy a twin-screw 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, After 17 years of development, now we have 20,000 square meters workshop with annual sales over 300+ sets, export over 60 countries.
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.
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.
Nanjing Team sincerely invite you to attend The 15th China Chongqing Rubber, Plastics Industry Exhibition.
Our booth no.: S2544
Time: May 27-30, 2021
Address: Chongqing International Expo Center
Wish to meet you at there ;)
Nanjing Jieya Extrusion Equipment Co., Ltd. (referred to as "Jieya") was established in 2004. It has the manufacturing capacity of various types of production lines with an annual production and sales of more than 350 sets. Its comprehensive capability ranks in the forefront of the Nanjing twin screw extruders industry. The company focuses on the R&D and manufacturing of various production lines centered on co-rotating twin-screw extruders and single-screw extruders. The product applications cover compounding, modified granulation, polymerization, devolatilization, one-step molding, and recyclable resources, etc.
Project Director Mr Chen introduced that every industry has competition, but specific to a certain market segment, the competitors involved are different. Traditional physical blending and modification is the largest market for twin-screw extruders, so the competition is the most intense. For Jieya, the bio-degradable plastic market was changed greatly in 2021, and a considerable part of Jieya’s orders in 2021 also came from this market.
Mr Chen explained that the reason why bio-degradable plastics are singled out from the traditional blending and modification market is that there have been many entrants in this market in the past two years, which has led to the rapid expansion of the market scale. Therefore, from traditional compounding and extrusion to processing bio-degradable plastics, is it necessary to carry out certain technical reserves? Mr Chen said frankly that it depends on how much bio-degradable plastics companies want to achieve. Just like melt blown materials in 2020, some companies have astonishing shipments, and some companies choose to take the quality to a higher level. The bio-degradable material made by special equipment must be of higher quality.
Around 2010, Jieya began to get involved in bio-degradable-related projects. During this period, we saw the ups and downs of major companies, and also witnessed the gradual growth of some companies from small to large. Most of these surviving companies are in the bio-degradable market. They started foreign trade before they became popular, and some companies even achieved a market share of about 30% in the export of Chinese vest bags.
He also talked about some distressing points in the biodegradable market: at present, the Chinese government has not clearly stipulated the definition and criteria of "bio-degradable". For example, some regions regard photo-degradable as a kind of bio-degradable. Many people oppose this. Mr Chen said that at present, most people in the Chinese market think that 'bio-degradable' is compostable and degradable, and garbage must be sorted and recycled before composting is possible.
However, Mr Chen is still very optimistic about the development of bio-degradable plastics. Bio-degradable must be the general trend of future social development, but the specific direction remains to be verified. Jieya has a layout for the main bio-degradable plastic categories, such as targeting for many PBAT projects launched in China in the past two years, we are actively discussing with customers whether we can directly use the twin-screw extruder in the polymerization stage to directly make modified materials (without extruding PBAT raw materials). Jieya has also followed up on the project of carbon dioxide production of PPC bio-degradable materials and PGA synthesized with glycolide. At present, the bio-degradable plastics market is still developing and improving. What we need to do now is to develop the corresponding twin-screw technology with the industrial chain. Based on the accumulated experience of a large number of practical applications to continuously improve the stability of the equipment.
Under the big goal of carbon neutrality, some very big changes have taken place in industries such as home appliances and automobiles. The intuitive impact is that Jieya has recently received some projects for recycling, dismantling, and regranulating waste household appliances, as well as the crushing, recycling, and regranulation of some new energy battery shells, which is also one of the important markets for Jieya in 2021. Mr Chen said that these manufacturers have multiple production lines and large projects, but they are usually new entrants, and usually require suppliers to provide them with whole-plant project planning, so they put forward higher requirements for suppliers' project experience and service capabilities.
Fluorochemicals, another key application area for which Jieya is recognized. Fluoroplastics are also known as "plastic kings". Their corrosion resistance, solvent resistance, weather resistance and temperature resistance are relatively good, so they are often included in the field of special engineering plastics. The most well-known is the PVDF used with lithium battery binder. In 2021, Jieya also undertook some projects in this field.
Mr Chen believes that the Chinese market is developing very fast, and twin-screw extruder enterprises must keep abreast of customer needs in order to gain a foothold in the market. Therefore, Jieya is also seeking new development in the upstream links. For example, the twin-screw devolatilization extrusion unit developed to meet the growing demand of downstream customers for products with low VOC and low residue; as well as corrosion resistance and wear resistance under high temperature conditions. The extrusion unit meets the production needs of special products under severe working conditions.
The success of Nanjing Jieya in the market is inseparable from the technical advantages of its twin-screw extruder equipment: its core components are all self produced, including high-torque gearboxes, extruder barrels, extruder screw elements, screen changer, die, etc. The product quality is stable and controllable, which can meet the personalized customization needs of customers, and the delivery time is flexible. In addition, Jieya stable team has also played a huge advantage. It is said that its sales, technology, management, and after-sales teams have an average of more than 10 years of experience in the industry. They have rich industry experience and are relatively clear about the pain points of various market segments. Provide complete personalized solutions, and can also undertake large and complex complete system projects.
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.
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.