The special refining effect and excellent performance of the single screw extruder have been proved in practice. Practice has proved that the reciprocating single-screw mixing extruder is a new type of plastic extrusion equipment. The emergence of single screw extruder provides a high-performance plastic processing equipment for the majority of users. Made a huge contribution to the development of the plastics industry.
What is the function of the single screw extruder operation screen?
What is the significance of the emergence of a single screw extruder?
What are the application fields of single screw extruder?
The operating panel is installed above the single screw extruder and can be rotated within 60 degrees for easy operation. There is a power indicator and emergency stop button on the right side of the touch screen. In an emergency, press the emergency stop button to stop immediately, which is used to protect the safety of the operator and the single screw extruder. The data recording, parameter setting, operation control and other operations of the entire instrument are all completed in this operation screen.
In the process of polymer processing, in order to give the polymer certain processing characteristics or to give the product specific use performance, it is often necessary to blend different polymers or blend the polymer with various additives and pigments. The single-screw extruder has the characteristics of uniform shearing, high dispersion, high filling, and stretching of the melt. And it combines the advantages of single and twin screw extruders. The unique working principle, coupled with a complete set of threaded components and supporting equipment, makes it more widely used. On a single screw extruder, it can achieve mixing, Mixing, plasticizing, dispersing, shearing, stretching, degassing, and granulation make the interface area of the melt flow in the machine far larger than the general shear flow.
The reciprocating single-screw mixing extruder is a new type of plastic mixing processing equipment, which is widely used in the filling, blending, modification, crosslinking, grafting, color masterbatch, functional masterbatch, and resistance of various plastics. Production of fuel masterbatch, conductive material, degradable masterbatch, reinforcement, toughening and other special plastic materials.
Blending different types of polymers to obtain brand new polymer alloys with specific uses.
Various mineral fillers are added to the polymer melt to make high-filling materials with excellent performance and low price.
Production of various glass fiber reinforced and flame retardant products, with the addition of glass fiber up to 50%.
It is suitable for the production of various cable sheathing materials, insulating materials, cross-linking materials, semiconductors, shielding materials, and conductive materials.
Production of thermoplastic elastomers and hot melt adhesives.
The single screw extruder is increasingly used in industrial production.Nanjing JlEYA has committed itself to offering the best-suited single screw extruders at a reasonable price, and all that is necessary to meet the needs of the customer.
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.
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.
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.
The basic mechanism of the twin screw extrusion process is simply that a screw rotates in the barrel and pushes the plastic forward. The screw structure is a bevel or ramp wrapped around a central layer, the purpose of which is to increase the pressure to overcome the higher resistance. What do I need to pay attention to when using a twin screw extruder? The following is a detailed description.
Here is the content list:
l Structural principles
l Temperature principles
l Speed reduction principle
For the extruder, there are three kinds of resistance to overcome when working: one is friction, which contains the friction of the solid particles (feed) on the barrel wall and the mutual friction between them during the first few turns of the screw (feed area); the second is the adhesion of the melt on the barrel wall, and the third is the resistance of the internal logistics of the melt when it is pushed forward.
According to Newton's theorem, if an object is at rest in a certain direction, then the object is in a state of equilibrium balance of forces in this direction. For the circumferential movement of the screw, it is no axial motion, that is, the axial force on the screw is in equilibrium. So if the screw exerts a large forward thrust on the plastic melt, it also exerts a backward thrust on another object of the same magnitude but in the same direction. The thrust is exerted on the thrust bearing behind the feed opening. Most single screws have right hand threads, and if viewed from the back, they rotate backward, and they spin backward out of the barrel by rotational motion. In some twin screw extruders, however, the two screws rotate backward and cross each other in both barrels, so one must be right handed and one left handed, and in the case of an occluding twin screw, both screws rotate in the same direction and must therefore have the same orientation. However, in either case, there are thrust bearings that withstand backward forces and still comply with Newton's theorem.
Plastics extruded by twin screw extruders are thermoplastics, which melt when heated and solidify again when cooled. Thus, heat is needed during the extrusion process to ensure that the plastic can reach the melting temperature. So where does the heat to melt the plastic come from? First of all, the pound feed preheat and barrel/die heaters may play a role and are very important at startup. In addition, the motor feed energy, the frictional heat generated in the barrel as the motor overcomes the resistance of the viscous melt and turns the screw, is the most important heat source for all plastics, except for small systems, low speed screws, high melt temperature plastics, and extrusion coating applications. In operation, it is important to recognize that the barrel heater is not the primary heat source and that it may play a smaller role in extrusion than we might expect. The post barrel temperature is more important because it affects the rate of solids transport in the dentition or feed. In general, except for a specific purpose (such as varnishing, fluid distribution, or pressure control), the die head and die temperature should be at or near the temperature required for the melt.
In most twin screw extruders, the screw speed is varied by adjusting the motor speed. The drive motor usually turns at a full speed of about 1750 rpm, which is too fast for an extruder screw. If it turns at such a fast speed, too much frictional heat is generated and a uniform, the well mixed melt cannot be prepared because the retention time of the plastic is too short. A typical speed reduction ratio should be between 10:1 and 20:1, with either a gear or pulley set for the first stage, but with a gear and a screw positioned in the center of the last large gear for the second stage. For some slow running machines (eg. twin screws for UPVC), there may be three reduction stages and the maximum speed may be as low as 30 rpm or less (ratio up to 60:1). On the other hand, some very long twin screws for mixing can run at 600 rpm or faster, thus requiring a very low reduction rate and more deep cooling. If the reduction rate is incorrectly matched to the job, too much energy will be wasted. It may be necessary to add a pulley set between the motor and the first deceleration stage where the maximum speed is changed, which either increases the screw speed even beyond the previous limit or reduces the maximum speed. This increases the available energy, reduces the current value, and avoids motor failure, in both cases, the output may increase due to the material and its cooling needs.
If you still have questions, you can consult our company. Nanjing JlEYA is the leading professional manufacturer of twin screw extruders in China.
The extrusion technology used by the single screw extruder is making waves in the food production industry. We know that single screw extruder can mass produce enterprise products of various shapes and textures. It allows a seamless and continuous operation process, which means that this means lower costs and higher production and sales.
What are the reasons and solutions for the poor discharge or blockage of the single screw extruder head?
What is the importance of single screw extruder temperature control?
What is the importance of single screw extruder speed control?
1. Reasons: (1) A certain section of the heater does not work, and the material is poorly plasticized. (2) The operating temperature is set too low, or the molecular weight distribution of the plastic is wide and unstable. (3) There may be foreign objects in the single screw extruder that are not easy to melt.
2. Treatment method: (1) Check the heater and replace it if necessary. (2) Verify the set temperature of each section, negotiate with the technician if necessary, and increase the temperature set value. (3) Clean and check the extrusion system and head of the single screw extruder.
Temperature control refers to the temperature of the single screw extruder during plastic extrusion, including the temperature control of the barrel, die and transition body. These temperature controls are related to the viscosity of the material, the sensitivity to temperature, and the aggregation state of the polymer. In general, the temperature of the die head and transition body of single screw extruder is low for medium and low viscosity materials, and the temperature of die head and transition body for high viscosity materials is high, and the fluidity is good.
Speed control means that for single screw extrude processing, if the screw speed increases, the shear rate increases. Thermoplastic melts are mostly non-Newtonian pseudoplastic fluids, and their viscosity decreases with the increase of shear rate, and fluidity Increasing the extrusion output also increases. However, if the shear rate is too large, the melt viscosity is too low, which will cause difficulties in the production and operation of single screw extrude. At the same time, the low-viscosity melt will flow backwards under the action of the screw back pressure, and the leakage flow will increase significantly, which will affect the output to a certain extent. , Again, the screw may even slip at high speeds, so the screw speed should be controlled within a certain range. In addition, in the production process of single screw extrude, the screw speed should be kept as stable as possible to avoid fast and slow. Otherwise, it will cause uneven discharge due to excessive changes in the melt viscosity of the material, which will affect normal production.
Nanjing JlEYA is a single screw extruder manufacturer established for more than five years. We work with customers from design to completion to ensure that all technical requirements are met.
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.
Each type of product in the plastic extruder line has its operating characteristics, and a detailed understanding of its operating characteristics is necessary to give full play to the effectiveness of the machine. The following is a detailed description of the operating procedures and maintenance methods for plastic extruders.
Here is the content list:
The plastic extruder is one of the machine types, master the extruder operation points, the correct and reasonable use of a plastic extruder. The use of plastic screw extruder includes a series of links such as installation, adjustment, commissioning, operation, maintenance, and repair of the machine, and its use has the commonality of general machines, mainly in the drive motor and reduction and speed change device. However, the working system of the plastic screw extruder, the extrusion system, is unique, and special attention should be paid to its characteristics when using the plastic screw extruder. Extruder manuals generally have clear provisions for the installation, adjustment, and commissioning of the machine, here the main points of the operation, maintenance, and repair of the plastic screw extruder are briefly described as follows: in particular, to correctly grasp the structural characteristics of the screw, heating and cooling management instrumentation characteristics and assembly, the correct extrusion process conditions, the correct operation of the machine.
1.Pastic extruder equipment should be placed in a ventilated position to ensure that the heat of the motor work prolongs its life; the machine should be kept well grounded.
⒉Regularly check the tool screws, the plastic extruder after 1 hour of use, with tools to tighten the moving knife, fixed knife screws, to strengthen the fixed between the blade and the knife frame; should be regularly filled with lubricating oil to ensure the lubrication between the bearings; to ensure the sharpness of the cutting edge of the tool, should always check the tool to ensure its sharpness, to reduce unnecessary damage to other parts caused by the blunt lack of the blade; regularly check whether the belt is loose, and timely tightening.
3. Restart - Before starting the plastic extruder for the second time, the remaining debris in the machine chamber should be cleared to reduce the starting resistance. Periodically open the inertia cover and pulley cover to clear the ash outlet under the flange, which can cause the powder to enter the shaft bearing.
4. Replacement parts - When replacing knives, the clearance between the moving and fixed knives should be 0.8 MM for crushers over 20 HP and 0.5 MM for crushers under 20 HP. The thinner the recycled material is, the gap can be adjusted appropriately larger.
If you need to know more, you can consult our company. The company focused on co-rotating twin-screw compounding extruders with the core of the various R&D and manufacturing, such as a twin-screw extruder, mini twin screw extruder, plastic extruder, parallel twin-screw extruder, and so on, the application covers compounding mixing modified granulation, polymerization, devolatilization, step molding, renewable recycling, and other fields.