








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.
Malfunctions that are caused by inadequate or improper maintenance can result in high repair costs and unnecessarily long gearbox down times. Regular servicing and inspection work are therefore imperative!
All servicing and repair work is only allowed to be performed with the gearbox stationary and by trained,authorized and appropriately instructed personnel.
Refilling lubrication oil
The oil level is to be checked regularly.It must never be below the bottom mark. In the case that the oil level drops below the minimum,it is imperative that the lubricant is topped up. The oil is only allowed to be topped up with the drive units shut down. A funnel with a filter is to be used for toppcng up (filter mesh 40um). The gearbox is always to be filled with the same type of oil as used previously It is not allowed to mix different oils or oils from different manufacturers.
Changing oil
The effectiveness of the oil reduces with increasing use due to soiling (foreign bodies and water) and chemical changes(ageing products). When the soiling and/or ageing is/are excessive, it is necessary to change the oil. Regular oil analyses provide information on the effectiveness of the gearbox oils. For larger quantities of oil it is recommended to make oil changes dependent on the results of an oil analysis.A missed oil change increases the risk of damage and can result in premature failure of the gearbox.
The first oil change should be made at approx.2500 perating hours.Subsequent oil changes depend on the state of the oil and are to be performed every 4,000 to 6,000 operating hours, however at the latest after one year.
The gear box is the core part of the twin screw extruders, we shall pay attention to its maintenance for long servicelife.
With the development of modern industry, the underwater pelletizing machine has become an important production equipment used in all aspects of production.
What is the working principle of the underwater pelletizing machine?
What is the operating procedure of the underwater pelletizing machine?
What are the reasons why people choose underwater pelletizing machine?
The material using the underwater pelletizing machine will pass through the feeding port, and under the action of the rotating screw, it will be rolled into a dough and roll forward along the screw groove. Due to the shear, compression and agitation of the screw, the material will be further mixed and plasticized. , The temperature and pressure gradually increase, showing a state of viscous flow, and passing through the machine head with a certain pressure and temperature, and finally a product of the desired shape is obtained.
(1) Check the rotation direction of the impeller of the underwater pelletizing machine. From the feed inlet, the impeller should turn counterclockwise, otherwise the motor connection should be adjusted.
(2) The starting sequence of the underwater pelletizing machine and the material conveying equipment is as follows:
Discharge belt conveyor→PL vertical impact crusher→feeding belt conveyor
The crusher must be started without load, and the material can only be fed after the crusher is running normally.
(3) The feed size is strictly in accordance with the feed size specified by the various models. It is forbidden to enter the underwater pelletizing machine with the size of the material larger than the specified size, otherwise it will cause the impeller imbalance and excessive wear of the impeller, and even block the impeller flow path and The central feed pipe prevents the crusher from working normally. When a large piece of material is found, it should be removed in time.
(4) When the discharge belt conveyor stops running, the feeding should be stopped immediately, so the discharge belt conveyor should be interlocked with the feeding system to open and stop. Otherwise, the impeller will be crushed and the motor will be burnt.
(5) The feeding of the underwater pelletizing machine should be uniform and continuous.
(6) During the operation of the underwater pelletizing machine, there must be no violent vibration or abnormal noise, otherwise, it should be stopped immediately for inspection, and the machine can only be driven in order after the fault is removed.
(7) The observation door should be sealed tightly during the working process of the underwater pelletizing machine.
The difference between the underwater pelletizing machine and other similar products is that it has a steady stream of water flowing through the mold surface, and it is in direct contact with the mold surface. The size of the pelletizing chamber is just enough to allow the pelletizing knife to rotate freely across the die surface without restricting the temperature of the water flow. The molten polymer has been extruded from the die, and the rotating knife cuts the pellets. And then the pellets are taken out of the pelletizing chamber by the temperature-regulated water and enter the centrifugal dryer. In the dryer of the underwater pelletizing machine, the water will be drained back to the storage tank, cooled and recycled; the pellets pass through the centrifugal dryer to remove the water.
This is how we see the irreplaceable role of underwater pelletizing machine in our daily lives and industrial production. Nanjing JlEYA, the pioneer of underwater pelletizing machine producing company in China, knows that every application is special. You can go and get more information about them
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:
Extrusion system
Drive System
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.
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.
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The single screw extruder is mainly composed of 3 parts: extrusion system, transmission system, and heating and cooling system. The following is a detailed introduction to the basic structure of the single screw extruder.
Here is the content list:
Extrusion system
Transmission system
Heating and cooling system
The main role of the extrusion system of the single-screw extruder is to melt and plasticize the polymer material to form a uniform melt, to realize the transformation from the glassy state to the viscous flow state. And in this process to establish a certain pressure, by the screw continuous extrusion delivery to the head die. Thus, the extrusion system plays an important role in the molding quality and output of the extrusion process.
The extrusion system mainly includes the feeding device, screw, and barrel, which is the most critical part of the extruder, of which the screw is the heart of the extruder, the material through the rotation of the screw in order to move in the barrel and get pressurized and part of the heat.
The drive system of a single screw extruder is usually composed of a motor, reducer, and bearing, whose role is to drive the screw and supply the torque and torque required by the screw in the extrusion process. During the extrusion process, the screw speed is required to be stable and does not change with the change of screw load to ensure the uniform quality of the product. However, in different situations, the screw is required to be able to achieve variable speed in order to achieve a machine that can adapt to the requirements of extruding different materials or products of different shapes. In most extruders, the change of screw speed is achieved by adjusting the motor speed. The drive system of the single-screw extruder is also equipped with a good lubrication system and a device for rapid braking.
The heating and cooling system of a single screw extruder consist of a heating device and cooling device, which are necessary for the extrusion process to be carried out smoothly. The heating and cooling devices must ensure that the polymer materials are melted and plasticized and the temperature conditions during the molding process meet the process requirements.
The cooling device is generally set up in the extruder barrel, screw and hopper bottom, and other parts. Barrel cooling can be water-cooled or air-cooled, air-cooled is generally used for small and medium-sized single-screw extruders; large single-screw extruders are mostly water-cooled or a combination of the two forms. The cooling device at the bottom of the hopper is mainly to strengthen the solid material conveying effect, to prevent the material particles from becoming sticky due to the heating, blocking the material mouth and thus affecting the feeding. Generally, for extruders with a screw diameter of 90mm or more and high-speed extruders, a cooling device must be installed at the bottom of the hopper.
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The single screw extruder is a special reduction power device designed for plastic and rubber single screw extruder equipment. The reducer is matched with the motor. The gear parts are made of high-strength alloy steel. The gears are processed by carburizing, quenching, and high-precision gear grinding. The gear accuracy is level 6, and the tooth surface hardness is HRC58-62.
What is the principle of single screw extruder?
What is the current industry development of single screw extruder?
What should I pay attention to when using single screw extruder?
The single screw extruder is generally divided into three sections in effective length. The effective length of the three sections is determined according to the diameter of the screw and the pitch and depth of the screw, which are generally divided into one-third of each; the last thread of the single screw extruder has been called the conveying section. It is required that it cannot be plasticized, but it must be preheated and compressed;
The second section of the single screw extruder is called the compression section. At this time, the volume of the screw groove gradually decreases, and the temperature must reach the degree of plasticization of the material. The compression produced here is from the conveying section three, and here it is compressed to one. Some machines also have Change, the plasticized material enters the third stage;
The third section of the single screw extruder is the metering section, where the material maintains the plasticizing temperature to supply the machine head, which is generally slightly higher than the plasticizing temperature.
In single screw extruder equipment, the plastic extruder is normally referred to as the main machine and the following equipment, the plastic extruder, is referred to as the auxiliary machine. After more than 100 years of development, the plastic extruder has been derived from the original single-screw extruder, a variety of models such as double-screw, multi-screw and even non-screw models have been derived. The plastic extruder (host) can be used with different plastic moulding machines such as tube, foil, holding material, monofilament, flat wire, strapping, extruding network, plate material, profile material, pelleting, cable coating, etc. are used. Suitable for different plastic extrusion production lines for the production of different plastic products. Therefore, plastic extrusion machines are today and in the future one of the most common models in the plastics processing industry.
What should I pay attention to when using single screw extruder?
(1) The material convey way of the single screw extruder mainly relies on friction, which limits its feeding performance. And it is difficult to add the powder, paste, glass fiber and inorganic fillers, so pay attention to the material used.
(2) When the pressure of the single screw extruder head is high, the reverse flow will increase and the productivity will decrease. Therefore, always pay attention to the pressure of the equipment.
(3) The surface renewal effect of the single screw extruder material in the exhaust zone is small, so the exhaust effect is poor.
(4) single screw extruder is not suitable for certain processes, such as polymer coloring, thermosetting powder processing, etc.
The single screw extruder has achieved an irreplaceable position in industrial production. Nanjing JlEYA is committed to providing various bending and rolling machines of high quality for all customers from all over the world.
Each type of product in the plastic extruder line has its operating characteristics, and a detailed understanding of its operating characteristics is necessary to give full play to the effectiveness of the machine. The following is a detailed description of the operating procedures and maintenance methods for plastic extruders.
Here is the content list:
Operation procedures
Maintenance methods
The plastic extruder is one of the machine types, master the extruder operation points, the correct and reasonable use of a plastic extruder. The use of plastic screw extruder includes a series of links such as installation, adjustment, commissioning, operation, maintenance, and repair of the machine, and its use has the commonality of general machines, mainly in the drive motor and reduction and speed change device. However, the working system of the plastic screw extruder, the extrusion system, is unique, and special attention should be paid to its characteristics when using the plastic screw extruder. Extruder manuals generally have clear provisions for the installation, adjustment, and commissioning of the machine, here the main points of the operation, maintenance, and repair of the plastic screw extruder are briefly described as follows: in particular, to correctly grasp the structural characteristics of the screw, heating and cooling management instrumentation characteristics and assembly, the correct extrusion process conditions, the correct operation of the machine.
1.Pastic extruder equipment should be placed in a ventilated position to ensure that the heat of the motor work prolongs its life; the machine should be kept well grounded.
⒉Regularly check the tool screws, the plastic extruder after 1 hour of use, with tools to tighten the moving knife, fixed knife screws, to strengthen the fixed between the blade and the knife frame; should be regularly filled with lubricating oil to ensure the lubrication between the bearings; to ensure the sharpness of the cutting edge of the tool, should always check the tool to ensure its sharpness, to reduce unnecessary damage to other parts caused by the blunt lack of the blade; regularly check whether the belt is loose, and timely tightening.
3. Restart - Before starting the plastic extruder for the second time, the remaining debris in the machine chamber should be cleared to reduce the starting resistance. Periodically open the inertia cover and pulley cover to clear the ash outlet under the flange, which can cause the powder to enter the shaft bearing.
4. Replacement parts - When replacing knives, the clearance between the moving and fixed knives should be 0.8 MM for crushers over 20 HP and 0.5 MM for crushers under 20 HP. The thinner the recycled material is, the gap can be adjusted appropriately larger.
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