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Our booth no.: B06
Time: June 23-25
Add: Hainan International Convention and Exhibition Center
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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.
Product Description
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
Technical indicators:
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.
When the single screw extruder is in the extrusion molding process, its extruder screw is divided into 3 sections: feeding section (feeding section), melting section (compression section), metering section (homogenization section), these three sections Correspondingly, three functional areas are composed of materials: solid conveying area, material plasticizing area, and melt conveying area. Each area has different temperature requirements, and specific problems should be analyzed in detail. The temperature of the single screw extruder will be briefly introduced below.
What is the general temperature of the solid conveying zone in a single screw extruder?
What is the general temperature in the plasticizing zone of the material in a single screw extruder?
What is the general temperature of the melt conveying zone in a single screw extruder?
What is the general temperature of the solid conveying zone in a single screw extruder?
The temperature of the barrel in the solid conveying zone of the single screw extruder is generally controlled at 100~1400C. If the feeding temperature is too low, the solid conveying zone will be extended, reducing the length of the plasticizing zone and the melt conveying zone, which will cause poor plasticization of the single screw extruder product and affect product quality.
What is the general temperature in the plasticizing zone of the material in a single screw extruder?
The temperature of the material plasticizing zone in the single screw extruder is controlled at 170~1900C. Controlling the vacuum degree of this section is an important process index. If the vacuum degree is low, it will affect the exhaust effect, resulting in bubbles in the pipe, and seriously reducing the mechanical properties of the pipe. In order to make the gas inside the material easily escape, the plasticization degree of the material in this section should be controlled not to be too high, and the exhaust pipe of the single screw extruder should be cleaned frequently to avoid blockage. The vacuum degree of the barrel is generally 0.08~0.09MPa.
What is the general temperature of the melt conveying zone in a single screw extruder?
The temperature of the melt conveying zone in the single screw extruder should be slightly lower, generally 160~1800C. Increasing the screw speed in this section, reducing the head resistance and increasing the pressure in the plasticizing zone are all conducive to the improvement of the conveying rate. For heat-sensitive plastics such as PVC, the residence time should not be too long in this section. The screw speed is generally 20 ~30r/min. The head of the single screw extruder is an important part of extruded product molding. Its function is to generate a higher melt pressure and make the melt shape into a desired shape. The process parameters of each part of the single screw extruder are: die connector temperature 1650C, die temperature 1700C, 1700C, 1650C, 1800C, 1900C.
This is some information related to the use of single screw extruders. The use of single screw extruders is also closely related to the quality of its products. If you need more information, please contact Nanjing JlEYA.
The 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.
Twin-screw extruders have barrels with an extension range of 4 and 6D, allowing for precise process design to meet specific customer requirements. All barrels allow for precise temperature control. Cooling is achieved by cooling water injection and high-performance electric heating rods for direct and fast heating. The auxiliary equipment of the twin-screw extruder consists of a straightening device, a preheating device, and a cooling and heating device. The following is a detailed description of the auxiliary equipment.
Here is the content list:
l Straightening device
l Preheating device
l Cooling device
One of the most common types of plastic extrusion rejects is eccentricity, and bending of the wire core in various patterns is one of the most important causes of insulation eccentricity. In sheath extrusion, scratches on the sheath surface are also often caused by the bending of the cable core. Therefore, a variety of extrusion units in the straightening device is essential. The main types of straightening devices are roller type (divided into horizontal and vertical type); pulley type (divided into single pulley and pulley group); stranded pulley type, which plays a variety of roles such as dragging, straightening, and stabilizing tension; pressure pulley type (divided into horizontal and vertical type), etc.
Cable core preheating is necessary for both insulation extrusion and sheath extrusion. For the insulation layer, especially the thin layer of insulation, the existence of pores should not be allowed, the core can be completely removed from the surface of the water, oil, and dirt through high temperature preheating before extrusion. For the sheath extrusion, the main role is to dry the cable core, to prevent the role of moisture (or moisture around the bedding layer) to make the sheath in the possibility of porosity. Preheating can also prevent the plastic from being extruded due to sudden cooling and residual internal pressure. In the process of extruding plastic, preheating can eliminate the cold line into the high-temperature heat, in contact with the plastic at the mouth of the die to form a disparity in temperature, to avoid fluctuations in plastic temperature and lead to fluctuations in extrusion pressure, to stabilize the amount of extrusion and ensure the quality of extrusion. Extrusion unit is used in the electric heating core preheating device, requires sufficient capacity, and ensures rapid temperature rise, so that the core preheating and cable core drying efficiency. The preheating temperature is restricted by the speed of wire release, generally similar to the temperature of the head.
The formed plastic extrusion layer after leaving the head should be immediately cooled and shaped, otherwise, deformation will occur under the action of gravity. The way of cooling usually uses water cooling, and according to the water temperature is different, divided into rapid cooling and slow cooling. Rapid cooling is the direct cooling of cold water, rapid cooling of plastic extrusion layer sizing is beneficial, but for crystalline polymers, due to sudden heat cooling, easy to internal residual stress in the extrusion layer organization, resulting in the use of the process of cracking, general PVC plastic layer using rapid cooling. Slow cooling is to reduce the internal stress of the product, in the cooling water tank placed in sections of different temperatures of water, so that the product gradually cool down and set, PE, PP extrusion on the use of slow cooling, that is, after hot water, warm water, cold water three cooling.
If you are engaged in a twin-screw extruder-related industry, you can consider our cost-effective products.
DRIVE SECTION
The drive section of the twin screw extruder consists of 3 parts: motor, clutch, and gearbox.
The reduction and distribution gear unit reduces the motor speed to the screw shaft speed and distributes the input torque to the two output shafts. Clutch is installed between the drive motor and the gearbox drive shaft.
PROCESSING SECTION
The processing section of the twin screw extruder in SHJ series extruder consists of individual barrel sections which are replaceable. Depending on the process tasks, reserve feed port, liquid injection port or twin screw side feed port is available.
Owing to the modular design of the twin screw extruder screw elements and screw barrels, conveying, plasticizing, homogenizing, pressure build-up and devolatilization zones can be established, depending on the process task.
For product intake and conveying, screw elements are used. The extruder can be fed with powder, pellets, chips, melt, paste, etc.
Plasticizing, mixing and dispersing are done by the twin screw extruder kneading elements. By varying the thickness of the kneading disks and their angle of stagger, their mixing, shearing and dispersing action can be adjusted to the individual requirements.
The screw elements are arranged on screw shafts. The co-rotating and closely intermeshing screw shafts have a sealing profile.
The screw barrels are supported by barrel supports. Axial displacement of the processing section resulting from thermal dilatation is absorbed by these supports.
EXTRUSION PART
The discharge section of the twin screw extruder consists of die head and screen changer, which is installed at the end of twin screw extruder discharging direction. There are several types of die heads and screen changers to meet the requirements of different polymers and processing technology.
Today, we loaded 2x40HQ export to Vietnam.
One is SHJ-50 twin screw extruder, the other is SHJ-72 twin screw extruders. Both extruders are used for making filler masterbatch.
Nanjing Jieya is a leading manufacturer of twin screw compounding extruders with over 20 years experience. We will offer you the top quality with best price.
We warmly welcome your inquiry.
Degradable plastics refer to a class of plastics whose various properties can meet the requirements of use, remain unchanged during the shelf life, and can be degraded into environmentally harmless substances under natural environment conditions after use. Therefore, it is also called environmentally degradable plastic.
There are a variety of new plastics: photodegradable plastics, biodegradable plastics, light/oxidative/biodegradable plastics, carbon dioxide-based biodegradable plastics, thermoplastic starch resin degradable plastics.
There are two main areas for the use of degradable plastics: one is the area where ordinary plastics were originally used. In these areas, the difficulty of collecting used or post-consumer plastic products will cause harm to the environment, such as agricultural mulch and single-use plastic packaging, and the second is areas where plastics are used instead of other materials. The use of degradable plastics in these areas can bring convenience, such as ball tacks for golf courses, and seedling fixing materials for tropical rainforest afforestation.
Specific applications are:
1.Agriculture, forestry and fishery, plastic film, water-retaining materials, seedling pots, seedbeds, rope nets, slow-release materials for pesticides and agricultural fertilizers.
2.Packaging industry, shopping bags, garbage bags, compost bags, disposable lunch boxes, instant noodle bowls, buffer packaging materials.
3.Sporting goods, golf tacks and tees
4.Hygiene products, women's hygiene products, baby diapers, medical mattresses, disposable haircuts.
5.Medical materials, bandages, clips, small sticks for cotton swabs, gloves, drug release materials, and surgical sutures and fracture fixation materials.
Nanjing Jieya also manufactures twin screw compounding extruder for bio-degradable material. We warmly welcome your inquiry.