Three Screw Extruder
Why Choose Us
High Quality
Since it is founder, COLOWE has focused on quality and have stood out for the flexibility and attention given to every single need of each customer.
Customized services
During the design stage COLOWE study the best solutions for each customer's business, customising machines with each customer who choose COLOWE .
Professional Team
Our professional team collaborate and communicate effectively with one another, and are committed to delivering high-quality results. They are capable of handling complex challenges and projects that require their specialized expertise and experience.
Rich Experience
Our company has many years of production work experience. The concept of customer-oriented and win-win cooperation makes the company more mature and stronger.
What is Three Screw Extruder
Three-screw extruder is composed of three screws, gear box, motor, temperature control system and other components. Among them, the three screws are the core components for extruding plastics, and the diameters and lengths of the screws are designed according to the production needs. The gap between the screws should be as small as possible to ensure good plasticizing and exhausting effect of the plastic in the extrusion process. Compared with single-screw extruders, three-screw extruders have a higher processing capacity and can extrude higher quality plastic products.
Advantages of Three Screw Extruder
High shearing efficiency and good plasticizing effect
A pair of screws have one meshing point, while triple screws have three meshing points. That is, it is equivalent to three pairs of twin screws, so the shear efficiency is higher and the material is easier to plasticize.
Close training function and good dispersion effect
The number of triple screws is one more than that of the twin screw. In short, the material only rotates two turns in the twin-screw extruder, but three turns in the three screw extruder. The extrusion and kneading of the material in the triple screw extruder is basically 1.5 times that of the twin screw extruder, so the triple screw extruder is a very dispersive machine integrating densification and extrusion.
High output and low energy consumption
Its output is twice that of a twin screw extruder with the same specification and power. For the production of the same number of products, the cost of manpower, site, etc. is reduced e xponentially. Because of its short length diameter ratio and the decrease of host power and heater power, it can save energy.
Good exhaust performance
In fact, the parallel co-rotating triple screw extruder has other advantages in other fields, such as good exhaust performance, materials are sucked into the “internal mixing area” of the extruder, and it is not easy to emit materials. Therefore, the vacuum degree is high, and the product quality is also improved.
The residence time of materials in the barrel can be greatly shortened
For easily degradable and heat-sensitive materials, the triple screw extruder also has great advantages. Because of the particularity of the three screws, the length diameter ratio of the same model can be shortened, and the residence time of materials in the barrel can be greatly shortened.
Twin Screw Extruder VS. Triple Screw Extruder
Product design
The most prominent design distinction lies in the number of screws. Twin screw extruders are equipped with two parallel screws that rotate in the same direction, whereas triple screw extruders are designed with three screws, which can rotate either co-rotating or counter-rotating. This difference in screw count fundamentally shapes their design and operation.
Twin Screw Extruder: The twin screw extruder comprises two screws that intermesh and rotate within the barrel. These screws can be co-rotating or counter-rotating, depending on the desired processing requirements. The design allows for better mixing, melting, and conveying of materials, making it suitable for a wide range of applications.
Triple Screw Extruder: On the other hand, the triple screw extruder incorporates three intermeshing screws that rotate within the barrel. This design offers enhanced material processing capabilities, particularly in terms of mixing, dispersion, and devolatilization. The additional screw provides increased surface area for heat transfer, making it ideal for applications requiring precise temperature control.
Operation
Mixing Efficiency: The additional screw in triple screw extruders significantly enhances their mixing efficiency. The three screws work in tandem to provide intensive mixing, making them particularly suitable for applications where thorough blending and dispersion are essential.
Throughput Capacity: The presence of an extra screw in triple screw extruders allows them to handle larger material volumes and achieve higher throughput rates compared to twin screw extruders. This makes triple screw extruders ideal for high-volume production processes.
Exhaust Performance: The triple-screw extruder’s exhaust port remains free from material accumulation, ensuring no material leakage or blockage. This is primarily because nearly all the material is drawn into the central honey refining area within the screw. The mixing area functions like a melt pump, resulting in a consistently high vacuum level. As a result, the machine can attain a superior vacuum, thereby enhancing product quality.
Specialized Applications: While twin screw extruders are versatile and adaptable to a wide range of materials and applications, triple screw extruders are often chosen for more specialized tasks. These include processing high-viscosity materials, polymer compounding, masterbatch production, and chemical processes demanding intensive mixing and reaction.
The quality of the manufactured product
Firstly, the twin-screw extruder produces 50% conductive carbon black masterbatch, which must go through banburying. However, the three-screw extruder does not need an internal mixer, and the material can directly enter the triple-screw extruder to produce 50% carbon black masterbatch. If the masterbatch is bitten with teeth, it will be flat, cracked and not broken, indicating that the produced masterbatch Granular toughness.
Because the three-screw extruder is fully plasticized and the components are evenly dispersed, it is used to blow a 0.005mm film, and the test results are very uniform. With the help of stirring, the three-screw extruder can produce more concentrated carbon black masterbatches, and the particles have better toughness.
The 85% calcium carbonate produced by the twin-screw machine is used to fill the PE or PP masterbatch, and it will be broken with a pinch of your fingers.
The masterbatch with the same ratio produced by the three-screw machine cannot be pinched with fingers, and it cannot be broken by dehydration and drying with a centrifugal dehydrator.
In the manufacturing of flame-retardant PP cable materials, the product obtained from the twin-screw extruder, following the banburying process with an aspect ratio of 40, exhibits a tensile strength of 13 MPa and an elongation of 185%. Conversely, the material produced by the three-screw extruder without internal mixing boasts a tensile strength of 14 MPa and an elongation of 237%. Furthermore, the three-screw extruder has the capability to process masterbatch with aluminum powder or antimony trioxide filling up to 70%, whereas the twin-screw extruder cannot achieve this level of processing.
Molecular grafting function
Triple Screw Extruder: Everyone knows that high melt strength polypropylene (HMS-PP) must be used for PP foaming, which requires molecular grafting of ordinary PP, and its price is much more expensive than ordinary PP. The molecules have branches and have sufficient melt strength and ductility to be suitable for PP foaming.
However, after our tests, ordinary PP (both homopolymerized and copolymerized PP can be used) can be directly used to produce good EPP beads after being extruded by a three-screw machine, and the expansion ratio can reach 70 times. This is because ordinary PP has been molecularly grafted during the flow process in the three-screw machine and has become polypropylene with high melt strength.
Twin Screw Extruder: A twin screw extruder can be used for various material processing applications, including compounding and blending, but it does not possess inherent molecular grafting capabilities. Molecular grafting typically involves the chemical modification of polymer chains by introducing new functional groups onto the polymer backbone. This process typically requires specialized equipment and chemical reactions beyond the capabilities of a standard twin screw extruder.
Processing capabilities
Twin Screw Extruder: The twin screw extruder stands out in a multitude of processing functions, such as compounding, blending, and reactive extrusion. Its adept mixing capabilities facilitate the integration of additives, fillers, and reinforcements into the base material, leading to enhancements in product characteristics. Furthermore, the twin screw extruder is versatile, capable of handling materials spanning a broad viscosity spectrum, from low to high viscosity.
Triple Screw Extruder: In a triple screw extruder, the processed materials undergo three shearing actions with each revolution of the screws. Additionally, the trefoil configuration within the barrel creates three cutting points, a notable contrast to the single cutting point in a standard twin screw extruder. Consequently, the triple screw extruder offers exceptional processing capabilities, especially in applications that necessitate high shear rates and thorough mixing. Its capacity to achieve superior dispersion and devolatilization makes it particularly well-suited for demanding processes like reactive extrusion, reactive blending, and reactive foaming. Furthermore, the triple screw extruder excels in handling highly viscous materials with remarkable ease.
Advantages and applications
Twin Screw Extruder: The twin screw extruder’s versatility and efficiency make it a popular choice in industries such as plastics, food processing, pharmaceuticals, and chemical manufacturing. Its ability to handle a wide range of materials and achieve excellent mixing and compounding results in improved product quality and reduced production costs.
Triple Screw Extruder: The triple screw extruder’s advanced processing capabilities make it indispensable in industries requiring precise control over material properties. Its applications include polymer modification, reactive extrusion of polymers, devolatilization of polymers, and specialty chemical production. The triple screw extruder’s ability to achieve superior dispersion and devolatilization results in enhanced product performance.
Technological formulas and after-sales
With the long-term emergence of twin-screw extruders, various related technical formulas are more stable than those of three-screw extruders.
In addition, because the twin-screw extrusion appeared earlier and has a long history, there are many twin-screw manufacturers, and the after-sales is relatively more secure than the three-screw extruder.
Both twin screw extruders and triple screw extruders offer unique advantages and cater to different processing requirements. The twin screw extruder excels in versatility and efficient mixing, while the triple screw extruder provides advanced processing capabilities for demanding applications. Understanding the differences between these extruder types allows industries to choose the most suitable option based on their specific needs, ultimately leading to improved product quality and process efficiency.
• Better plasticizing and mixing effect: The arrangement of triple screw ensures excellent self-cleaning effect. Compared with the traditional twin screw extruder, the screw meshing area has doubled, greatly improving the mixing effect of the screw. In many working conditions, it can replace the traditional internal mixer and reciprocating single screw extruder.
• The length diameter ratio of screw is shorter, the residence and mixing time of material is longer.
• Higher output: Tthe output of triple screw extruder is more than 50% higher than that of the same twin screw extruder.
• More energy saving: Three screw extruder saves 20% – 40% energy than traditional twin screw extruder.
Three-screw extruder is widely used for material processing and molding in plastic, rubber, chemical, food and other industries. Screw extruder is an important plastic processing equipment, which has a wide range of applications in the processing of plastics, rubber and other polymer materials. The core component of a three-screw extruder is three side-by-side screws, which are usually arranged in a zigzag pattern and rotate in the same direction. This design is equivalent to the combination of two pairs of twin screws, which gives it unique advantages in material plasticization, melting and extrusion. In addition, the meshing area of the three screws allows for higher shear efficiency The principle of operation of the three-screw extruder is primarily based on melting plastics in a high-temperature, high-pressure environment through a specific process. The rotation of the screw pushes the material forward so that it is extruded through the screw head. During the extrusion process, the material is subjected to strong shearing and mixing effects, thus achieving uniform plasticization and melting. In the process of extrusion, the material is subjected to strong shearing and mixing, thus achieving uniform plasticization and melting.
Working principle of three screw extruder
The working principle of three-screw extruder is to melt the plastic under high temperature and high pressure through specific process, and then make the plastic extruded from the head of screw through the advancement of screw. The specific steps are as follows:
Feeding
Add plastic granules or powder into the hopper of the extruder.
Melting
By heating the screw, the plastic is heated and melted.
Extrusion
Extrudes the melted plastic through the extruder outlet and through the mold.
Cutting
Cut the molded product into desired length.
Three-screw extruder is composed of three screws, gear box, motor, temperature control system and other components. Among them, the three screws are the core components for extruding plastics, and the diameters and lengths of the screws are designed according to the production needs. The gap between the screws should be as small as possible to ensure good plasticizing and exhausting effect of the plastic in the extrusion process. Compared with single-screw extruders, three-screw extruders have a higher processing capacity and are able to extrude higher quality plastic products.
What Are the Factors to Be Considered When Selecting a Three Screw Extruder?
Production capacity
According to the production needs, select the equipment with appropriate production capacity.
Number and length of screws
According to the different types of plastics, the equipment with appropriate number of screws and appropriate length should be selected.
Motor power
The power of the motor should match the production capacity of the equipment.
Equipment material
The equipment should be made of high quality stainless steel to ensure the corrosion resistance and durability of the equipment.
Precautions for the use of three screw extruder
Check before use
• Before starting the screw extruder, a comprehensive inspection must be carried out to ensure that all safety guards are intact, and all operating components have been correctly installed and are in normal working condition. Especially for the mechanical parts, they should be carefully checked to prevent accidents caused by loosening and other problems.
• Check the electrical and power parts to ensure that the electrical system is reliable, the cables are novel and well grounded.
• The surrounding area should be kept clear, if there is any restriction on the type of need to be delivered, before the operation of the attention to clean up the site debris.
Precautions during operation
• In the process of extrusion, attention should be paid to the timely elimination of glue stagnation, faults and abnormalities, and reasonable organization and treatment. Do not disassemble the equipment or make unauthorized and unapproved changes.
• When changing die heads, maintenance and cleaning and other operations, attention must be paid to safe operation, and arms, fingers and hair, etc. must not be close to the rotating parts and motion transmission mechanism to avoid danger.
• Minimize public hazards such as exhaust gas, waste and noise generated by the operation of the machine, and do a good job of environmental protection.
Because of the high requirements of the three-screw extruder, the electrical system should be separated from the production and manufacturing field and installed with ventilation or air-exchange fans. It is recommended to place the electrical control cabinet in a simple room, maintain the room clean and ventilated so that the room temperature is not higher than 40°C.
Three-screw extruder is not allowed to idle to prevent roughening of the screw and barrel. Run the mainframe at low speed first, check whether there is any abnormal ringing sound after running the mainframe, and then gradually increase the mainframe speed to within the permissible range of processing technology. When the new machine break-in period, the current load will be raised normal use should be 60-70%, the current does not exceed 90%. Note: If there is any strange noise during the operation of the extruder, the equipment should be stopped immediately for inspection or repair.
Turn on the oil pump before starting the machine and turn it off after stopping the machine operation; the water pump maintains the working condition during the whole production process, the water pump shall not stop running, in order to prevent the barrel temperature from rising and causing the decomposition and carbonization of the materials in the barrel, the asbestos cover of the main fan shall be cleaned frequently to prevent the dust from adhering to too much and blocking the cover, which will cause insufficient heat dissipation of the motor and the tripping of the over-temperature.
Remove the dirt, tools and debris on the surface of the unit in a timely manner. It is strictly required to prevent metal or other debris from falling into the hopper to prevent damage to the screw and barrel. In order to prevent iron impurities from entering the cylinder, can be installed in the cylinder inlet magnet absorber or magnetic frame in order to prevent foreign objects from falling into the material must be screened in advance.
Our factory
Established in 2014,COLOWE is recognized one of China's poineer for twin screw extruder,banbury kneader compouding machine,two-stage screw compounding extruder,three screw compuding machine.since it is founder, COLOWE has focused on quality and have stood out for the flexibility and attention given to every single need of each customer.During the design stage COLOWE study the best solutions for each customer's business, customising machines with each customer who choose COLOWE .
FAQ
