Weigh the complete feeding system (silo, feeder and bulk material) through static scales and control the discharge flow of bulk materials through variable speed motors or electric vibrators. Material is discharged from the system (via screw, vibrating tube or trough), the "loss" measured per unit of time (dv/dt) is compared to the required feed rate (preset value), the actual (measured) The difference between the flow rate and the desired (preset) flow rate generates a corrective signal through the dosing controller, which automatically adjusts the dosing rate to maintain the accurate dosing amount without process lag. When the weight measured in the silo reaches the low level of the silo (refilling), the controller will control the feeding system according to the volumetric feeding, and then the silo will be reloaded quickly (manually or automatically), and the weight loss controller will restart . In a batch loss-in-weight system, the design is similar to a continuous loss-in-weight system, however, the accuracy of the final weight of the feed (batch) cycle is higher than the actual feed amount control. The controller accomplishes fast dosing by providing a high dosing signal to the variable speed drive, then transitions to a low dosing control signal for precise control at the end of the batch. Technical parameter
Metering accuracy ≤0.5%
Ingredient accuracy ≤0.5%
Batching measurement control range 0.01-300t/h
Scope of application
Continuous stabilized soil, cement batching in concrete mixing plants, sintering quantitative control feeding, coal powder quantitative control feeding and batching of various thick slurries, etc.
Product introduction of loss-in-weight scale: the loss-in-weight feeder consists of a hopper, a feeder (single and double-shaft screw feeder), a weighing system and a regulator. During operation, the hopper, material and feeder are weighed continuously. As the material is delivered, the actual rate of weight loss is measured and compared to the desired rate of weight loss (set point). Automatically corrects for deviations from setpoint by adjusting feeder rates. Thus, the material can be fed continuously and evenly and accurately.
Applicable scope: granule, powder, calcium carbonate, talcum powder, resin film powder, flour, starch, etc. Powder gravimetric feeder: solves the problem of feeding metering and feeding with poor fluidity while pellet gravimetric feeder solve any bridging problems that may occur.
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(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 difference between single screw extruder and twin screw extruder: one is a screw, the other is two screws. Both are driven by a motor. The power varies with different screw sizes. The power of 50 conical twin screw extruder is about 20kW, and 65 is about 37kW. The output is related to the material and the screw size. The output of 50 conical twin screw extruder is about 100-150kg/h, and 65 conical twin screw extruder is about 200-280kg/h. The output of a single screw is only half than twin screw extruder.
Extruders can be divided into single-screw, twin-screw and multi-screw extruders according to the number of screws. Today, the single-screw extruder is the most widely used and is suitable for extrusion processing of general materials. The twin-screw extruder has the characteristics of less heat generated by friction, relatively uniform shearing of the material, large conveying capacity of the screw, relatively stable extrusion volume, long residence of the material in the barrel, and uniform mixing.
The single-screw extruder occupies an important position both as a plasticizing and granulating machine or a molding and processing machine. In recent years, the single-screw extruder has made great progress. The large-scale single-screw extruder for granulation produced in Germany has a screw diameter of 700mm and an output of 36t/h.
The main sign of the development of single-screw extruder lies in the development of its key part, the screw. In recent years, people have carried out a lot of theoretical and experimental research on screws. There are nearly 100 types of screws. The common ones are separation type, shear type, barrier type, split type and wave type.
From the perspective of single-screw development, although the single-screw extruder has been relatively complete, with the continuous development of polymer materials and plastic products, new and special single-screw extruders with more characteristics will emerge. In general, single-screw extruders are developing in the direction of high speed, high efficiency and specialization.
The twin-screw extruder has good feeding characteristics, is suitable for powder processing, and has better mixing, exhaust, reaction and self-cleaning functions than single-screw extruders, and is characterized by processing plastics and blends with poor thermal stability. It shows its superiority even more.
The twin screw extrudernot only has the characteristics of a single-screw extruder, but also has the advantages of convenient feeding, stable extrusion, and convenient exhaust. It is widely used in the production and processing of extruded products.
Why are twin screw extruders warmly welcomed now?
Choose a single-screw extruder or a twin screw extruder?
What are the technical points of the twin screw extruder?
Why are twin screw extruders warmly welcomed now?
The twin screw extruder can not only add more ingredients to the company's products, but also can choose to quickly complete the manufacturing. Considering that "new crown pneumonia" has put every industry into trouble, the market has been looking for a quick turnaround to pay for healthy food. In addition, you may need to make up for the loss of production and sales or increase production and sales based on the current situation. Twin-screw extension can help you, and considering the lower cost and higher production and sales, it can bring more profits.
Choose a single-screw extruder or a twin screw extruder?
The single-screw extruder is used for extrusion processing technology and equipment, and the particle raw materials stay in the extruder for a long time. This means that a single-screw extruder requires a longer period than a twin screw extruder to produce the products required by the enterprise. In addition, the twin screw extruder allows you to better control the complex operation process and actual operation. As everyone knows, these controls are much more complicated. This is very important for foods that need to be mixed and mixed. The production and manufacturing facilities are complete, and the actual effect of twin-screw extrusion is the best. For polymer materials, twin-screw extrusion is also particularly effective. Considering that the design concept of twin screw extruder has a relatively large flexibility, it can be used in many industries for very specific operation processes.
What are the technical points of the twin screw extruder?
In the extrusion process of the twin screw extruder, the material is transformed from the glass state to the molten state. In addition to the balance between the heat required for plasticization of the material and the amount of heat supplied, the material is melted. Pressure is also a very important control indicator. Because the material is affected by the compression ratio of each section of the die resistance screw during the extrusion process, it does not exist under normal pressure. For different die, the compression ratio of each section of the screw is basically constant and immutable. Under the premise of the same extrusion speed, increase or decrease the feed rate, the volume of the screw material in the feeding section will change, and the volume of the material in the exhaust section will remain unchanged, so the compression section of the feeding section changes with the compression ratio, and its melt pressure follows Increase or decrease; under the premise of the same feed rate, increase or decrease the extrusion rate, the volume of the screw material in the feeding section will also change. The volume of the material in the exhaust section remains unchanged, so the compression section of the feed section changes with the compression ratio, and its melt pressure increases or decreases accordingly; the feed speed increases or decreases simultaneously with the extrusion speed, because the volume of the screw material in the feed section remains unchanged , Only due to the increase or decrease of the speed, the melt pressure change.
Due to different fields and different types of twin screw extruder, they are widely used in many industries. To meet these growing demands, Nanjing JlEYA has committed to providing the increasing of twin screw extruder.
The engineering plastic twin screw extruder consists of a transmission device, a feed device, a barrel, and a screw. The function of each component is similar to that of a single-screw extruder. The difference to the single screw extruder is that in the engineering plastic twin screw extruder two parallel snails are arranged in the "cross-section" of the material.
What is the working principle of the engineering plastic twin screw extruder?
How do you treat a engineering plastic twin screw extruder?
Why is the cooling device particularly important when using engineering plastic twin screw extruders?
From the point of view of the principle of movement, the engineering plastic twin screw extruder distinguishes between the straight and uneven, and non-foaming types.
1. Double screw extruder of technical plastic
This type of engineering plastic twin screw extruder has a low speed and a high speed. The former is mainly used for profile extraction, while the latter is used for special polymer processing operations.
(1) Tightly machined extruder. The slow-running extruder has a closely combining screw geometry, in which the spiral antenna shape of one snail closely matches the spiral antenna shape of the other snail, i.e. the conjugated snail shape.
(2) Self-cleaning extruder. The simultaneous high-speed extruder has a closely tuned spiral shape. This type of snail can be executed with a relatively small snail split so that the snail has a closed self-cleaning effect. This type of engineering plastic twin screw extruder is called a compact self-cleaning engineering plastic twin screw extruder.
The gap between the two screw edges of the closely combining, opposing engineering plastic twin screw extruder is very small (much smaller than the gap in the evenly rotating engineering plastic twin screw extruder) so those positive conveying properties can be achieved.
2. Non-reciprocating double screw extruder of technical plastic
The axis distance between the two snails of the non-foaming engineering plastic twin screw extruder is greater than the sum of the radii of the two snails.
1. After using the engineering plastic twin screw extruder for 500 hours, iron chips or other impurities from the gears are in the gearbox. Therefore, the gears should be cleaned and the gear lubricant replaced.
2. The engineering plastic twin screw extruder should carry out a comprehensive inspection of the extruder after an operating period to check the density of all snails.
3. If the double screw extruder is suddenly switched off during production, the main drive, and the heating stops, if the power supply is restored, each section of the cylinder shall be reheated to the specified temperature and kept for a specified period, before you can start the extruder.
4. If the display and the display of the engineering plastic twin screw extruder are full, check if the contact of the thermocouple, etc. is good.
After the molded plastic extrusion layer has left the engineering plastic twin screw extruder, it should be cooled and formed immediately, otherwise, it will deform under the influence of gravity. The cooling method normally uses water cooling and is divided into quick cooling and slow cooling according to the different water temperatures. Fast cooling is the direct cooling by cold water. Rapid cooling is advantageous for the design of the extruded plastic layer, but in the case of crystalline polymers, due to sudden heat cooling, it is easy to leave internal stresses in the extruded layer structure, which leads to cracks during use. Generally PVC The plastic layer is deterred. Slow cooling should reduce the inner tension of the product. Water with different temperatures is given in the cooling water tank to gradually reduce the temperature and shape of the product. The extrusion of PE and PP takes place under slow cooling, i.e. through hot water, hot water, and cold water, which is called three-stage cooling.
Nanjing JlEYA is the leading manufacturer extruder manufacturer specializing in twin screw extrude. If you want to get more information, just go and connect them.
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.
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.
The underwater pelletizing machine is a smart machine with a touch screen, supports touch input, and is equipped with an Android system. The main engine of the underwater pelletizing machine is an extruder, which consists of an extrusion system, a transmission system and a heating and cooling system.
What are the possible failures of the underwater pelletizing machine and their solutions?
What are the advantages of the underwater pelletizing machine?
What are the applicable materials for the underwater pelletizing machine?
Cause analysis: underwater pelletizing machine cutter wears excessively or the cutter blade is damaged, the particle water flow is too low, the pelletizer vibration is too large, the cutter and the template are not tightly attached, the material melt index fluctuates, and the discharge flow rate is inconsistent. Excessive water temperature and other reasons can cause the shutdown of the underwater pelletizing system and cause the interlocking shutdown of the entire unit.
Solution: After stopping the underwater pelletizing machine, visually check whether the cutting edge of the cutting knife is excessively worn or damaged. If so, replace the cutting knife completely. Check and confirm whether the granular water leaks internally, whether the filter and cooler of the granular water tank are blocked. If they are blocked, they should be cleaned manually; check whether the inlet and outlet pressures of the granular water pump are normal. If not, check the valves on the granular water pump and the pump pipeline. Check whether the alignment between the cutter shaft and the underwater pelletizing machine is out of tolerance, whether the bearing assembly of the cutter shaft is damaged, and whether the cutter rotor is out of balance. During operation, check whether there is any gap in the contact between the four moving wheels of the pelletizing trolley and the guide rail. Control the volatile matter in the polypropylene powder and eliminate the vibration of the cutter and cutter shaft when it flows through the template hole. Reduce the temperature of the hot oil at the template of the underwater pelletizing machine, check the temperature distribution of the cylinder and the template, and whether the flow, pressure and temperature of the cooling water of the cylinder are normal; confirm the time setting for the "water, knife, material" to reach the template to prevent particles The water reaches the template prematurely and freezes the template hole. After closing the head of the underwater pelletizing machine, the feed volume should be quickly increased to the set load of the extruder.
The underwater pelletizing machine is a new model for pelletizing plastic materials that are elastic, easy to foam at low temperature, difficult to form, and have poor flow properties. The underwater pelletizing machine breaks through the traditional method of stranding pelletizing in the past. It overcomes the shortcomings of instability, uneven particles, easy agglomeration, and low output during the granulation of elastomer raw materials.
The underwater pelletizing machine is suitable for EVA, TPU and other materials with high viscosity and high viscosity of elastomers, and also suitable for conventional materials such as PP, PE, ABS, PA, and PC.
The widespread use of underwater pelletizing machines has continuously increased the demand for them in the market. Nanjing JlEYA, as a Chinese pioneer in underwater pelletizing machine, can ensure the machines’ quality and after-sales service.