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
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 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.
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 main machine of the plastic extruder is the extruder, which is composed of an extrusion system, transmission system, and heating and cooling system. The following is a detailed description of the composition of the plastic extruder.
Here is the content list:
Heating and cooling device
A homogeneous melt is plasticized bypassing the plastic through the extrusion system, which consists of a screw, barrel, hopper, head, and die.
The function of the drive system is to drive the screw, supplying the torque and speed required by the screw during the extrusion process, usually consisting of an electric motor, reducer, and bearings.
The manufacturing cost of the reducer is roughly proportional to its size and weight, provided that the structure is the same. Because the shape and weight of the reducer are large, it means that more materials are consumed in the manufacturing, and the bearings used are also larger, which increases the manufacturing cost.
For a similar screw diameter extruder, the high speed and high potency extruder consume additional energy than the traditional extruder, the motor power is doubled, and also the reducer seat range is raised consequently is critical，however a high screw speed means that an occasional reduction magnitude relation. For the same size reducer, the gear modulus of the low reduction ratio increases compared to the large reduction ratio, and the capacity of the reducer to bear the load also increases. Therefore, the rise in volume and weight of the reducer isn't linearly proportional to the rise in motor power. If the extrusion volume is employed because of the divisor and dividend by the burden of the reducer, the high speed and high potency extruder can have a smaller range and the normal extruder will have a larger number.
In terms of unit output, the small motor power and the small weight of the reducer of the high speed and high-efficiency extruder means that the manufacturing cost per unit output of the high speed and high-efficiency extruder is lower than that of the normal extruder.
Heating and cooling are necessary to enable the plastic extrusion process to proceed.
(1) Extruders usually use electric heating, which is divided into resistance heating and induction heating, with heating sheets installed in each part of the body, neck, and head. The heating device heats the plastic inside the barrel from the outside to warm it up to the temperature required for the process operation.
(2) The cooling device is installed to ensure that the plastic is in the temperature range required for the process. Specifically, it is to exclude the excess heat generated by the shear friction of the rotating screw to avoid the plastic from decomposing, scorching, or shaping difficulties due to the high temperature. Barrel cooling is divided into two kinds of water-cooled and air-cooled, generally small and medium-sized extrusion machine using air-cooled is more appropriate, large is more water-cooled or a combination of two forms of cooling; screw cooling is mainly used in the center of water-cooled, the purpose is to increase the rate of solid material delivery, stabilize the amount of rubber, while improving product quality; but the cooling at the hopper, one is to strengthen the role of solid material delivery, to prevent the plastic grain sticky blockage because of the heating the second is to ensure the normal work of the transmission part.
If you are engaged in the industry related to the extruder, you can consider our cost-effective products. Our company is a leading extruder manufacturer specializing in a twin-screw extruder, micro twin-screw extruder, plastic extruder, and parallel twin-screw extruder in China.
As common extruder equipment used in the plastic processing industry, single screw extruder is mainly used for extruding soft and hard PVC, polyethylene, and other thermoplastics, which can process many kinds of plastic products, such as blown film, extruded pipe, pressboard, drawn ribbon, etc. It can also be used for melt pelletizing. The plastic extruder has advanced design, high quality, good plasticization, low energy consumption, involute gear transmission, low noise, smooth operation, high load capacity, and long life. To have a long service life of the machine, maintenance measures are indispensable, the following is a detailed description of the single-screw extruder maintenance measures.
Here is the content list:
1. Because the electrical control system of single-screw extruder has high requirements for ambient temperature and dustproof, the electrical system should be separated from the production site, and install ventilation or ventilation fan, it is recommended that the electrical control cabinet in a simple room, keep the room clean, ventilation, so that the indoor temperature is not higher than 40 ℃.
2. Single-screw extruderis not allowed to run empty, so as not to roll the screw and machine simple hair. Host start idling is not allowed to exceed 100r / min; start the host first low speed, after starting the host to check for abnormal noises and then slowly increase the host speed to within the allowable range of the process (can be adjusted to the best state is good). When the new machine is breaking in, the current load should be at 60-70%, and the current in normal use should preferably not exceed 90%. Note: If an abnormal sound occurs when the extruder is running, it should be stopped immediately for inspection or repair.
3. Turn on the oil pump first and turn off the oil pump after shutting down the machine; keep the water pump working during the whole production process and do not stop the pump to avoid the barrel temperature rising and causing the material in the barrel to decompose and carbonize; the asbestos wind cover of the main motor fan needs to be cleaned often to avoid the dust sticking too much to block the wind cover and cause the motor to overheat and trip due to insufficient heat dissipation.
4. Clean up the dust and dirt, tools, and debris on the surface of the unit in time.
1.Regularly check the screws and other fasteners on the surface of the single-screw extruder unit for looseness and timely and proper tightening. The lubricant level of the transmission box should be added or replaced promptly (the dirt at the bottom of the oil tank should be cleaned regularly). For new machines generally, 3 months to replace the oil, after that every six months to a year. The oil filter and oil suction pipe should be cleaned regularly (once a month).
2. Single screw extruder gearbox maintenance and general standard reducer are the same. The main thing is to check the wear and failure of gears and bearings.
3, When reinstallation please note that A, B two screws must be in the original position, can not be replaced! After the installation of the new combination of the screw on the machine, you must first use the hand pan car, such as normal rotation before the low-speed start. Screw or barrel for a long time without use, there should be anti-rust and anti-fouling measures, the screw should be placed hanging. If the threaded block is with fire, the flame should be moved left and right, while burning to clean up, and can not burn too much (blue ringers red), not to mention the thread block into the water.
4. Regularly calibrate the temperature control instrument to check the correctness of its adjustment and the sensitivity of its control.
5. In the barrel with a cooling water tank, must be used distilled water to prevent the formation of scale blocking the cooling water channel in the barrel, resulting in temperature failure. Pay attention to the appropriate amount of water in use to prevent scaling. If the blockage should be changed down the cylinder specific maintenance, no blockage and the water output is small indicates that there is scale, the tank water should be changed to dilute hydrochloric acid swishing cycle, clear scale to normal and then change the distilled water. General water in the tank is used to cool the barrel, and the natural water we pass is used to cool the tank. Regularly check the water quality of the cooling water tank, if there is turbidity, should be replaced promptly.
6.Check whether the solenoid valve is working properly, the coil has not burned out if there is a timely replacement.
7. The temperature does not rise to quite the temperature continues to rise and fall may exist for the following reasons: whether the day electric couples loose fall; heater relay is working properly; solenoid valve is working properly, timely replacement of deformation of the heater, and tighten the screws.
8. Timely clean up the dirt in the vacuum tank, and the material in the exhaust chamber so that the pipeline is smooth. Vacuum pump seals need to be replaced promptly if there is wear and tear regular inspection, the output shaft jumping is bearing damage and shaft fracture must be opened and replaced, such as the gearbox two output shaft bearing position wear is too serious, the box must be replaced to avoid greater loss of failure.
9, To drive the screw rotation of the DC motor to focus on checking the brush wear and contact, the insulation resistance value of the motor whether in the specified value should also be measured frequently. In addition, check the connection line and other components that are rusted, and the use of protective measures.
10. When the single-screw extruder needs to stop using for a long time, should be in the screw, Jane, the head, and other working surfaces coated with anti-rust grease. The small screw should be suspended in the air or placed in a special wooden box, and a wooden block pad flat, so as not to deform the screw or bruise.
11. Single-screw extruder attached to the cooling water pipe wall is prone to scale external corrosion and rust. Maintenance should be carefully checked, too much scale will block the pipeline, can not achieve the cooling effect, rust will be serious leaks, so maintenance must take descaling and anti-corrosion cooling measures.
12. Designate a person responsible for the maintenance of equipment. And each maintenance and repair detailed record is included in the plant equipment management files.
If you still have questions, you can consult our company, we are happy to answer for you. The company insists on the purpose of "quality first, customer first", and warmly welcomes new and old customers to cooperate with us.
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.
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.
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.
The single-screw extruder has a simple design and a low price, so it is widespread and demand on the market was high.
What are the application areas and benefits of single-screw extruders?
What is the development history of the single-screw extruder?
What are the main technical parameters of the single-screw extruder?
The single-screw extruder is mainly used for extruding soft and hard polyvinyl chloride, polyethylene, and other thermoplastic. It can process a variety of plastic products such as films, tubes, plates, tapes, etc., can also be used for granulation.
The single-screw extruder is characterized by advanced design, high quality, good plasticization, and low energy consumption. It uses an evolutionary drive that is characterized by low noise development, stable operation, high load capacity, and long service life.
The single-screw extruder is one of the most important devices for the processing of plastic molding parts. It uses external energy transfer and heat transfer of external heating elements to carry out the transport of plastics solids, compaction, melting, shielding, and extrusion forms.
Since the birth of the snail extruder, it has evolved from an ordinary snail extruder to a new type of snail extruder after almost a hundred years of development. Although there are many types of new single-screw extruders, the extrusion machine is the same.
The extrusion process of the traditional snail extruder is realized by heating outside the cylinder, solid and cylinder, snail friction, and melting shear force.
"friction coefficient" and "friction force", "viscosity" and "shear tension" are the main factors influencing the performance of conventional screw extruders. The extrusion process from the machine is unstable and difficult to control, especially for some heat-sensitive plastics with poor thermal stability and high viscosity.
1. Screw diameter: refers to the diameter of the outer circle of the screw, marked with D, and the unit is millimeter (mm).
2. Proportion of screw length to diameter: refers to the ratio of the length L of the working part of the screw (the length of the threaded part, i.e. the length from the center line of the feed opening to the end of the screw) and the screw diameter D, expressed by L/D.
3. Snail speed range: refers to the highest speed of the snail up to the lowest speed of the snail; n is used to represent the speed of the snail, and the unit is revolutions per minute (U/min).
4. The power of the main screw drive engine: expressed by P, the unit is kilowatt (kW).
5. Heating performance of the extruder cylinder: expressed by E is the unit kilowatt (kV).
6. The output capacity of the extruder: expressed by Q, the unit is kilogram per hour (kg/h).
7. The height of the extruder rim: refers to the distance from the center line of the screw to the ground, expressed by H, and the unit is millimeters (mm).
8. Extruder outer dimensions: refers to total length (x) total width (x) total height expressed by L x B x H, and the unit is millimeters or meters (m m or m)
9. Extruder quality: expressed in W, the unit is kilogram or tonne (kg or t).
We can see the huge role that single-screw extruders play in the production industry, and they have become indispensable components. And Nanjing JlEYA a Chinese pioneer in single-screw extruder production,has committed to providing the most suitable single-screw extruder at a reasonable price, and whatever it takes to satisfy the customer’s needs.
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
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/