








The main system of the plastic extruder is the extrusion system, which includes screw, barrel, hopper, head, and die. The plastic is plasticized into a uniform melt by the extrusion system and is continuously extruded from the head by the screw under the pressure established in the process. The following are details about the plastic extruder extrusion system introduction.
Here is the content list:
Screw
Barrel
Hopper
Head and mold.
The screw is the most important part of the extruder, which is directly related to the application range and productivity of the extruder and is made of high-strength and corrosion-resistant alloy steel.
The barrel is a metal cylinder, generally made of heat-resistant, high-pressure strength, strong wear-resistant, corrosion-resistant alloy steel or composite steel tube lined with alloy steel. The barrel and the screw cooperate to realize the crushing, softening, melting, plasticizing, exhausting, and compacting of the plastic, and to continuously and evenly deliver the rubber to the molding system. Generally, the length of the barrel is 15-30 times its diameter, so that the plastic is fully heated and fully plasticized as a principle.
The bottom of the hopper is equipped with a cut-off device to adjust and cut off the material flow, and the side of the hopper is equipped with a sight hole and a calibrated measuring device.
The head is composed of alloy steel inner sleeve and carbon steel outer sleeve, the head is equipped with a molding mold, the role of the head is to transform the rotational movement of the plastic melt into a parallel linear motion, evenly and smoothly into the mold sleeve, and give the plastic to the necessary molding pressure. The plastic is plasticized and compacted in the barrel and flows through the neck of the head through a certain flow path through the porous filter plate into the forming mold of the head. The mold core and mold sleeve are properly matched to form an annular gap with decreasing cross-section so that the plastic melt forms a continuous dense tubular cladding layer around the core line. To ensure that the plastic flow channel in the head is reasonable and to eliminate the dead angle of the accumulated plastic, there is often a diversion sleeve placed, and to eliminate the pressure fluctuation of plastic extrusion, there is also a pressure equalization ring set. The head is also equipped with a die correction and adjustment device to facilitate the adjustment and correction of the concentricity of the die core and die sleeve.
The extruder head is divided into an angled head (120o angle) and a right angle head according to the angle between the head material flow direction and the screw centerline. The shell of the head is fixed to the body with bolts, the die inside the head has a die core sitting and is fixed to the head inlet port with a nut, the front of the die core seat is equipped with a die core, the die core and the center of the die core seat has a hole for passing the core line, the front of the head is equipped with an even pressure ring for equalizing the pressure, the extrusion package forming part is composed of die sleeve seat and die sleeve, the position of the die sleeve can be adjusted by bolts through the support to adjust the die sleeve to the die core The position of the die sleeve can be adjusted by bolts through support to adjust the relative position of the die sleeve to the die core, which is convenient to adjust the uniformity of the thickness of the extruded layer.
If you want to buy a plastic extruder or want to know more, you can visit our official website. Our website is https://www.njjyextrusion.com/
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.
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.
The twin screw extruder's standard equipment includes a sturdy base frame dedicated to housing the temperature control unit and oil lubrication system. The equipment features advanced control software for seamless integration into digital factories, ready for Industry 4.0, greatly improving ease of use. The following is a detailed description of the operating procedures of the twin screw extruder.
Here is the content list:
l Start up operation
l Stop the machine
l Precautions
Start up operation
1.Close the power main gate of the twin screw extruder.
2. Turn on the power at the operation panel: Press and hold the power button clockwise to turn and then release.
3. Set the temperature of each temperature zone: for example, a zone temperature according to the process requirements set the corresponding temperature, press the set button, and then adjust the up and down arrows to the desired temperature, press the set button.
4. Set the feeding rate: according to the process, requirements can be fed rate between 0 ~ 10 to set.
5. Set the host speed of the twin screw extruder: set the host speed between 0~30 according to the process requirements.
6. Add cooling water to the cooling tank.
7. In turn on the fan: press the operation button on the operation panel.
8. When you need to start the operation of the vacuum pump, you can start the vacuum pump.
9. Turn on the cutter switch.
1. Twin screw extruder normal stopping sequence: stop the feeder: close the vacuum line valve, open the vacuum chamber on the cover; gradually reduce the main screw speed; shut down the pelletizer and other auxiliary equipment: off the motor, each external water inlet valve.
2. Twin screw extruder emergency stop: (1) in case of an emergency need to stop the host, you can quickly press the electrical control cabinet red emergency stop button, and the host and the feed speed knob back to zero, and then the total power switch off. After eliminating the fault, you can restart the machine again in normal driving order. (2) encounter equipment automatic protection trip stop: need to set the various parameters knob to zero, and then reset the parameters, press the reset button and start the machine again.
1. The normal production of the first shift machine, be sure to first check whether the barrel, hopper seal is the original closed kind, such as changes or damage, should check the hopper, the machine inside the Jane there are no foreign objects.
2. Pay attention to the screw to start at a low speed, the air time can not exceed 3min.
3. Must pay attention to check the purity of each batch of material, do not allow any impurities mixed into the material.
4. The beginning of the material to pay attention to the first small amount, evenly added material, while paying attention to observe the current meter (torque meter) pointer changes.
For granular material, use metering to add material. When you first start to feed production, be sure to pay attention to the extruder production work overload phenomenon. After the forming die lip out of the material, and then gradually increase the screw speed as appropriate.
5. Often check the working condition of the motor carbon brush, abnormalities should be replaced or adjusted promptly.
6. The screw cleaning work is not allowed to use steel tools scraping material, the application of copper brush, shovel cleaning.
7. When the process temperature is suspected of displaying problems on the instrument, use mercury temperature, meter actual measurement of the machine Jane, and molding mold degree. Refer to the mercury temperature measured temperature, adjust the calibration instrument to show the temperature.
If you still have questions, you can consult our company. Our company's website is https://www.njjyextrusion.com/
The plastic extruder is a common plastic machinery equipment, in the process of the daily operation of the extruder, the extruder will have a variety of failures, affecting the normal production of plastic machinery, the following we will analyze the extruder failure.
Here is the content list:
Unstable host current
The main motor can not start
The head is not discharged smoothly or blocked
The main electric starting current is too high
The main motor makes an abnormal sound
1. Production reasons.
(1) Uneven feeding.
(2) The main motor bearing of the plastic extruder is damaged or poorly lubricated.
(3) A section of the heater is out of order and does not heat up.
(4) The screw adjustment pad is not correct, or the phase is not correct, and the component interferes.
2. Treatment methods.
(1) Check the feeder, troubleshooting.
(2) Overhaul the main motor of the plastic extruder, replace the bearings if necessary.
(3) Check whether each heater is working properly, replace the heater if necessary.
(4) Check the adjustment pad, pull out the screw to check whether there is interference with the screw.
1. Causes.
(1) There is a mistake in the start-up procedure of the plastic extruder.
(2) The main motor thread has a problem, whether the fuse is burned ring.
(3) The main motor-related chain device to function
2. Treatment methods.
(1) Check the program, reboot the machine in the correct boot sequence.
(2) Check the main motor circuit.
(3) Check whether the lube oil pump of the plastic extruder is started and check the status of the chain device associated with the main motor. The oil pump is not on and the motor cannot be turned on.
(4) The inverter induction power has not been discharged. Turn off the main power and wait for 5 minutes before starting again.
(5) Check whether the emergency button is reset.
1. Causes.
(1) A section of the heater does not work, and the material is not plasticized well.
(2) The operating temperature setting is low, or the molecular weight distribution of plastic is wide and unstable.
(3) There may be foreign substances that do not melt easily.
2. Treatment methods.
(1) Check the heater of the plastic extruder and replace it if necessary.
(2) Verify the set temperature of each section, and if necessary, consult with the technician to increase the temperature setting.
(3) Clean and check the extrusion system and the head.
1. Causes.
(1) Insufficient heating time and high torque.
(2) A section of the heater does not work.
2. Treatment methods.
(1) Apply hand pan machine when starting, if not easy, extend the heating time or check whether each section heater is working properly.
1. Produced by.
(1) The main motor bearing of the plastic extruder is damaged.
(2) The main motor silicon controlled rectifier line in silicon controlled damage.
2. Treatment methods.
(1) Replace the main motor bearings.
(2) Check the silicon-controlled rectifier circuit, if necessary, replace the silicon-controlled components.
Our company's website is https://www.njjyextrusion.com/. If you still have questions, you can contact us on the official website.
The high efficiency of the single-screw extruderis mainly reflected in high output, low energy consumption, and low manufacturing cost. In terms of function, the 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, building materials, packaging, ceramics, and other fields. So how to operate the single screw extruder? The following is a detailed introduction.
Here is the content list:
Preparation work before starting the machine
Start-up operation
Stop operation
1. For single-screw extruder extrusion production of materials, should meet the required drying requirements, if necessary, further drying.
2. According to the variety of products, size, select the head specifications, the machine will be installed in the order of the column, installed head flange, die body, mouth die, porous plate, and filter network.
3. Connect the compressed air pipe, install the core mold electric heating rod head heating ring, check the water system.
4. Adjust the gap evenly in all parts of the mouth die and check whether the centerline of the main machine and the auxiliary machine are aligned.
5. Start the single-screw extruder of each running equipment, check whether the operation is normal, and find faults in time to eliminate.
6. Turn on the electric heater, the head, body, and auxiliary machine evenly heated up, to be the temperature of each part than the normal production temperature of about 10 degrees, constant temperature of 30 ~ 60 minutes so that the machine temperature inside and outside the same.
Start-up is an important part of the production, poor control will damage the screw and head, the temperature is too high will cause plastic decomposition, the temperature is too low will damage the screw, barrel, and head. The start-up steps are as follows.
1. Start the machine at low speed, idle, check the screw for any abnormalities and motor, amperage meter current no overload phenomenon, the pressure gauge is normal. Machine idling should not be too long to prevent the screw and barrel-scraping grinding.
2. Gradually add a small amount of material, wait for the material extrusion out of the die, before the normal addition of material. Before the plastic is extruded, no one should be in front of the mouth die to prevent casualties.
3. After the plastic is extruded, it is necessary to lead the extruded material slowly on the cooling and shaping, traction equipment, and start this equipment beforehand. Then, according to the control instrument indication value and the requirements of the extruded products, each link will be properly adjusted until the extrusion operation reaches the normal state.
4. Cutting and sampling, checking whether the appearance meets the requirements, whether the size meets the standard, quickly testing the performance, and then adjusting the extrusion process according to the requirements of quality, so that the products meet the standard requirements.
1. Stop feeding, extrude the plastic in the single screw extruder and turn off the power of the barrel and head for the next operation.
2. Shut off the power of the main machine and the auxiliary machines at the same time.
3. Open the head connection flange, clean the porous plate and various parts of the head, when cleaning, should use copper rods, copper pieces, after cleaning, apply a little oil. Screw, barrel clean up, if necessary, the screw from the end of the machine out of the top, clean up after recovery, in general, available for the transition of material cleanup.
4. Extrusion of polyolefin plastics, usually in the extruder full load shutdown (with material shutdown), when the air should be prevented from entering the barrel, so as not to oxidize the material and affect the quality of the product when continuing production. For polyvinyl chloride plastics, can also stop with material, then close the material door, reduce the temperature at the head connection body (flange) 10 ~ 20 degrees, to stop the machine after the material squeeze net.
5. Close the total power and cooling water main valve.
If you still have questions, you can consult our company. Our company's website is https://www.njjyextrusion.com/
The screw can be said to be the heart of the injection molding machine. The quality of the screw determines the quality of the product. The plasticizing screw of the engineering plastic twin screw extruder has the functions of conveying, melting, mixing, compression, metering and exhausting. It plays an important role in the quality of plasticization and is a key factor affecting the quality of plasticization.
What is the difference between engineering plastic twin screw extruder and single screw extruder?
What are the characteristics of engineering plastic twin screw extruder?
What are the structural principles of engineering plastic twin screw extruder?
1. Price: single screw extruder has simple structure and low price; Engineering plastic twin screen expander is complex and expensive
2. Plasticizing capacity: single screw extruder is suitable for plasticizing and extruding polymers and granular materials. The shear degradation of polymer is small, but the residence time of material in extruder is long; The engineering plastic twin screw extruder has good mixing and plasticizing ability, and the residence time of materials in the extruder is short, which is suitable for powder processing.
3. In terms of processing capacity and energy consumption: the engineering plastic twin screw extruder has large output, fast extrusion speed and low energy consumption per unit output, while the single screw extruder is poor.
4. Operability: the single screw extruder is easy to operate and the process control is simple; The operation of engineering plastic twin screen expander is relatively complex and the process control requirements are high.
1. engineering plastic twin screw extruder is divided into parallel and conical according to the relative position of the two axes;
2. engineering plastic twin screw extruder is divided into meshing type and non-meshing type according to the two screw meshing procedures;
3. engineering plastic twin screw extruder is divided into the same direction and the opposite direction according to the rotation direction of the two screws, and there are inward and outward points in the opposite direction;
4. engineering plastic twin screw extruder is divided into high speed and low speed according to the screw rotation speed;
5. engineering plastic twin screw extruder is divided into whole and combination according to the structure of screw and barrel.
For the basic mechanism of the engineering plastic twin screw extruder process, in simple terms, a screw rotates in the barrel and pushes the plastic forward. The screw structure is an inclined surface or slope wound on the center layer, the purpose of which is to increase the pressure in order to overcome the greater resistance. As far as the engineering plastic twin screw extruder is concerned, there are three kinds of resistance that need to be overcome during work: one is friction, which includes the friction of solid particles (feeding) against the barrel wall and the first few revolutions of the screw (feeding zone). There are two kinds of mutual friction forces; the second is the adhesion of the melt on the cylinder wall; the third is the internal logistics resistance of the melt when it is pushed forward.
Nanjing JlEYA has focused on the development and production of engineering plastic twin screw extruders for several years. And it commits to provide perfect service for every customer from all over the world.
Plastic extruders can be divided into single-screw extruders, twin-screw extruders, and multi-screw extruders according to their number of screws. The following are the details of the types of plastic extruders.
Here is the content list:
Classification of plastic extruders
Single-screw extruder
Twin-screw extruder
Classification of plastic extruders
1, According to the number of screws, divided into single-screw extruders, twin-screw extruders, and multi-screw extruders.
2, According to the presence or absence of a screw in the extruder, divided into screw extruders and plunger extruders.
3, According to the running speed of the screw to divide:
Ordinary extruder: speed below 100r/min.
High-speed extruder: speed of 100 to 300r/min.
Super high-speed extruder: the speed is 300~l500r/min.
4, According to the extruder assembly structure classification: there are integral extruders and separate extruders.
5, According to the spatial position of the screw in the extruder, can be divided into the horizontal extruder and vertical extruder.
6, According to whether the extruder is in the process of exhaust and can be divided into exhaust type extruder and non-exhaust type extruder
Single-screw extruder
The single-screw extruder occupies an important position both as a plasticizing and pelletizing machine and as a molding machine, and in recent years, the single-screw extruder has developed greatly. Single-screw extruders were the first extruders to gain widespread application in the plastic processing and molding field due to their simple structure and high processing efficiency. Similarly, to meet different processing needs, various equipment manufacturers have explored various screw and barrel structures. The single-screw extruder has evolved from the basic pure screw structure to various structures such as damping screw block, exhaust extrusion, slotted screw barrel, pinned barrel, building block structure, etc., thus enabling the single-screw extruder to have a wider range of molding.
Due to the small footprint of single-screw extruders, they are almost the only equipment used in the compounding and blown film fields. Single-screw extruder technology has become an important part of the extrusion process market that cannot be ignored.
Twin-screw extruder
The twin-screw extruder has less heat generated by friction, more uniform shearing of the material, larger conveying capacity of the screw, more stable extrusion volume, long stay of the material in the barrel, and uniform mixing.
The twin-screw extruder has good feeding characteristics, is suitable for powder processing, and has better mixing, exhaust, reaction, and self-cleaning functions than the single-screw extruder, characterized by the processing of plastics with poor thermal stability and co-mingled materials show its superiority. Based on the twin-screw extruder, the multi-screw extruder was developed for easier processing of co-blends with poor thermal stability.
If you want to buy an 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, after 17 years of development, now we have 20,000 square meters workshop with annual sales over 300+ sets, export over 60 countries.