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 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.
Nanjing Team sincerely invite you to attend The 15th China Chongqing Rubber, Plastics Industry Exhibition.
Our booth no.: S2544
Time: May 27-30, 2021
Address: Chongqing International Expo Center
Wish to meet you at there ;)
Weigh the complete feeding system (silo, feeder and bulk material) through static scales and control the discharge flow of bulk materials through variable speed motors or electric vibrators. Material is discharged from the system (via screw, vibrating tube or trough), the "loss" measured per unit of time (dv/dt) is compared to the required feed rate (preset value), the actual (measured) The difference between the flow rate and the desired (preset) flow rate generates a corrective signal through the dosing controller, which automatically adjusts the dosing rate to maintain the accurate dosing amount without process lag. When the weight measured in the silo reaches the low level of the silo (refilling), the controller will control the feeding system according to the volumetric feeding, and then the silo will be reloaded quickly (manually or automatically), and the weight loss controller will restart . In a batch loss-in-weight system, the design is similar to a continuous loss-in-weight system, however, the accuracy of the final weight of the feed (batch) cycle is higher than the actual feed amount control. The controller accomplishes fast dosing by providing a high dosing signal to the variable speed drive, then transitions to a low dosing control signal for precise control at the end of the batch. Technical parameter
Metering accuracy ≤0.5%
Ingredient accuracy ≤0.5%
Batching measurement control range 0.01-300t/h
Scope of application
Continuous stabilized soil, cement batching in concrete mixing plants, sintering quantitative control feeding, coal powder quantitative control feeding and batching of various thick slurries, etc.
Product introduction of loss-in-weight scale: the loss-in-weight feeder consists of a hopper, a feeder (single and double-shaft screw feeder), a weighing system and a regulator. During operation, the hopper, material and feeder are weighed continuously. As the material is delivered, the actual rate of weight loss is measured and compared to the desired rate of weight loss (set point). Automatically corrects for deviations from setpoint by adjusting feeder rates. Thus, the material can be fed continuously and evenly and accurately.
Applicable scope: granule, powder, calcium carbonate, talcum powder, resin film powder, flour, starch, etc. Powder gravimetric feeder: solves the problem of feeding metering and feeding with poor fluidity while pellet gravimetric feeder solve any bridging problems that may occur.
The engineering plastic twin screw extruder was developed based on a single screw extruder. Due to its good feed performance, mixing and plasticization performance, suction performance, and extrusion stability, it is often used in extruded products.
What are the advantages of engineering plastic twin screw extruders?
What role do pre-heaters play in the use of engineering plastic twin screw extruders?
What is the reason for the "fault" of the exhaust air opening of the engineering plastic twin screw extruder?
By simply opening the engineering plastic twin screw extruder, the wear level of the threaded parts and the inner sockets of the cylinder can be determined at any time, so that we need to carry out effective maintenance or exchange. It is not detected if there is a problem with the extruded product causing unnecessary waste.
2. Reduce production costs
When a engineering plastic twin screw extruder is made of technical plastic Masterbatch, it is often necessary to change the color. It is necessary to change the product.
Simply open the open editing area within a few minutes. In addition, the mixing process can be performed by observing the melting profile on the entire screw. analysis. When changing the color of an ordinary engineering plastic twin screw extruder, a large amount of cleaning material is needed to clean the machine, which is time and energy consuming and wastes raw materials. The split engineering plastic twin screw extruder can solve this problem. When changing color, it takes only a few minutes to quickly open the barrel for manual cleaning, so that no or fewer cleaning agents can be used, which saves costs.
A pre-heating of the cable core is required for the use of an engineering plastic twin screw extruder. The presence of pores shall not be permitted for the insulating layer, in particular the thin insulating layer. The wire core can be completely removed from the water and oil surface by high-temperature preheating before crushing. In the case of coat extrusion, its main function is to dry the cable core to prevent the possibility of pores in the coat due to moisture (or moisture around the cushion layer). By preheating, the residual pressure of the plastic can also be prevented by discouragement during extrusion. During the plastic extrusion of the processor, preheating can eliminate the large temperature difference that occurs when the cold wire enters the high-temperature nozzle and the nozzle is in contact with the plastic, thereby avoiding the fluctuation of the plastic temperature and causing the fluctuation of the extrusion pressure. This stabilizes the extrusion volume and ensures the extrusion quality. The technical plastic engineering plastic twin screw extruder uses an electric radiator preheating device that requires sufficient capacity and guarantees rapid heating so that the core preheating and drying efficiency of the cable core is high. The pre-heat temperature is limited by the deflection speed and generally corresponds to the temperature of the machine part.
The temperature of the machine part is low and the pressure of the machine part is too high.
engineering plastic twin screw extruder The engineering plastic twin screw extruder used for profile extrusion is usually narrow-meshed and rotates in different directions, but a few also use simultaneous engineering plastic twin screw extruders, which usually work with relatively low screw speed. About ten U/min.
The rapidly combining, simultaneous engineering plastic twin screw extruder is used for composting, venting or as a continuous chemical reactor. The maximum snail speed of this extruder type is 300-600 U/min. The non-interactive extruder is used for mixing, venting, and chemical reaction. Its conveyor mechanism is very different from the interlocking extruder, which is closer to the conveyor mechanism of a single screw extruder.
These are related practices for using engineering plastic twin screw extruders. If you want to get more information about the engineering plastic twin screw extruders, please connect Nanjing JlEYA, and they will tell you more about it.
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:
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/
The engineering plastic twin screw extruder consists of a transmission device, a feed device, a barrel, and a screw. The function of each component is similar to that of a single-screw extruder. The difference to the single screw extruder is that in the engineering plastic twin screw extruder two parallel snails are arranged in the "cross-section" of the material.
What is the working principle of the engineering plastic twin screw extruder?
How do you treat a engineering plastic twin screw extruder?
Why is the cooling device particularly important when using engineering plastic twin screw extruders?
From the point of view of the principle of movement, the engineering plastic twin screw extruder distinguishes between the straight and uneven, and non-foaming types.
1. Double screw extruder of technical plastic
This type of engineering plastic twin screw extruder has a low speed and a high speed. The former is mainly used for profile extraction, while the latter is used for special polymer processing operations.
(1) Tightly machined extruder. The slow-running extruder has a closely combining screw geometry, in which the spiral antenna shape of one snail closely matches the spiral antenna shape of the other snail, i.e. the conjugated snail shape.
(2) Self-cleaning extruder. The simultaneous high-speed extruder has a closely tuned spiral shape. This type of snail can be executed with a relatively small snail split so that the snail has a closed self-cleaning effect. This type of engineering plastic twin screw extruder is called a compact self-cleaning engineering plastic twin screw extruder.
The gap between the two screw edges of the closely combining, opposing engineering plastic twin screw extruder is very small (much smaller than the gap in the evenly rotating engineering plastic twin screw extruder) so those positive conveying properties can be achieved.
2. Non-reciprocating double screw extruder of technical plastic
The axis distance between the two snails of the non-foaming engineering plastic twin screw extruder is greater than the sum of the radii of the two snails.
1. After using the engineering plastic twin screw extruder for 500 hours, iron chips or other impurities from the gears are in the gearbox. Therefore, the gears should be cleaned and the gear lubricant replaced.
2. The engineering plastic twin screw extruder should carry out a comprehensive inspection of the extruder after an operating period to check the density of all snails.
3. If the double screw extruder is suddenly switched off during production, the main drive, and the heating stops, if the power supply is restored, each section of the cylinder shall be reheated to the specified temperature and kept for a specified period, before you can start the extruder.
4. If the display and the display of the engineering plastic twin screw extruder are full, check if the contact of the thermocouple, etc. is good.
After the molded plastic extrusion layer has left the engineering plastic twin screw extruder, it should be cooled and formed immediately, otherwise, it will deform under the influence of gravity. The cooling method normally uses water cooling and is divided into quick cooling and slow cooling according to the different water temperatures. Fast cooling is the direct cooling by cold water. Rapid cooling is advantageous for the design of the extruded plastic layer, but in the case of crystalline polymers, due to sudden heat cooling, it is easy to leave internal stresses in the extruded layer structure, which leads to cracks during use. Generally PVC The plastic layer is deterred. Slow cooling should reduce the inner tension of the product. Water with different temperatures is given in the cooling water tank to gradually reduce the temperature and shape of the product. The extrusion of PE and PP takes place under slow cooling, i.e. through hot water, hot water, and cold water, which is called three-stage cooling.
Nanjing JlEYA is the leading manufacturer extruder manufacturer specializing in twin screw extrude. If you want to get more information, just go and connect them.