Operation, maintenance, and maintenance of the extruder (FAQ)
The right to use the extruder, can take advantage of the performance of the machine, maintain a good working condition, to extend the life of the machine.
The use of the screw extruder machine installation, adjustment, commissioning, operation, maintenance and repair of a series of links, its use with the general machinery of the common, mainly in the drive motor and gear transmission device. Screw extruder, extrusion systems, but the unique characteristics of the screw extruder should be special attention to its characteristics.
Machine installation, adjustment, testing in general are clearly defined in the manual in the extruder, extruder operating, maintenance and maintenance outlined as follows:
An extruder operation
Operating personnel must be familiar with their operation, the structural characteristics of the extruder, in particular, the proper understanding of the structural characteristics of the screw, the heating and cooling features, the nose features and assembly of control instruments, in order to properly grasp the extrusion process conditions, the correct to operate the machine.
Extrusion of different plastic products, methods of operation vary, but it has its similarities. The following brief introduction to the extrusion of a variety of products the same steps and the operator should pay attention to the matter.
1, driving the preparatory work before
(1) for the extrusion of plastic. Raw materials to achieve the required drying requirements, when necessary, for further drying. And sift the raw material to remove caking aggregate and mechanical impurities.
(2) inspection equipment, water, electricity, gas system is normal, to ensure water, gas road blocked, missed, whether the normal electrical system, heating system, temperature control, a variety of instruments and reliable; auxiliary empty low-speed test operation, observe whether the device is operating normally; start stereotypes vacuum pump, the observation is working properly; smooth parts in a variety of equipment lubrication. If failure is immediately removed.
(3) installed head and stereotypes. Based on product variety, size, selecting the head specifications. Head mounted in the following order.
① The head should be fitted together, the overall installed on the extruder.
② assembly head before coated with grease should wipe saved, carefully check the cavity surface bumps, scratches, rust, and make the necessary polishing and then coated with a layer of silicone oil in the surface of the flow channel.
③ in order to nose each plate assembly together, at the thread of the bolt is coated with high temperature grease, and then tighten the bolt and flange.
④ the porous plate is placed between the head flange to ensure that the compression plate without excess material.
⑤ In the mouth not tighten the head connected with the extruder flange fastening bolts should adjust the horizontal position of the die, the available level of proposed adjust the level of a square nose, round nose while the stereotyped model of rubber-soled surface reference using nose mold bottom surface leveling.
⑥ connection and tighten the flange bolts, tighten the head fastening bolts, install the heating coil and thermocouple, pay attention to the heating coil with the head outside surface snapping.
⑦ install the stereotypes set and adjust the place, check the host, setting set to align with the centerline of the tractor. Adjusted, tighten the bolts. Connection stereotypes sets of pipes and vacuum.
⑧ turn the heating power, uniform heating on the nose, the machine simply warming. Open at the same time plus the hopper bottom and gearbox cooling water and exhaust vacuum pump inlet valve. Insulation when the temperature of each heating are first transferred to 140 ° C, the temperature rose to 140 ℃ 30-40min, and then the temperature rose to normal production temperature. About 10min until the temperature rose to normal production of the desired temperature, and then to various parts of the machine temperature stabilized in order to car production. The length of holding time will vary according to different types of extruders and plastic varieties. Insulation for some time, the machine inside and outside the same temperature, in order to avoid the instrument indicates that the temperature has reached the required temperature, actual temperature is low, this time, if the material into the extruder, the actual temperature is too low, the melt viscosity of materials will caused by axial force overload and damage the machine.
⑨ to the car used raw materials into the hopper, ready to use.
(1) in a constant temperature after the car, before driving should be nose and extrusion machine flange bolts to tighten, to remove the bolt head thermal expansion differences in the order of the tight head bolts tighten the diagonal, forced to be uniform. Tight head flange nuts, requiring around the elastic, otherwise run material.
(2) drive, select "ready to drive" button, followed by "Drive" button, then slowly rotate the screw speed adjustment knob, screw speed slow start. And then gradually speed up, while a small amount of feeding. Feeding time to pay close attention to the instructions of the host ammeter and a variety of instructions header changes. The screw torque can not exceed the red label (usually 65% -75%) torque table. Before the plastic profiles extrusion, no person shall stand on the front of the die to prevent pull off because of the bolt or bubble because of raw material moisture release and other reasons arising from the injury accident. After the plastic extrusion die from the nose, one that takes the extrudate to cool slowly and onto the traction device and calibrator and switch these devices. Then the indicated value of the control instruments and extrusion products. The various parts to be adjusted accordingly, so that the entire extrusion operation to achieve the normal state. Needed to add a little material, twin-screw extruder with a metering feeder uniform constant velocity feeding.
(3) When the die material uniformity and excellent plastic for traction stereotypes. Plasticization of the need to judge by experience, usually to determine the appearance of the extrusion material, that is, surface gloss, no impurities, no foam, coke material and color, and hand out of material to squeeze down to a certain extent does not appear burrs, cracks, have some flexibility, then materials, plastics good. The plasticizing bad may be appropriate to adjust the screw speed, barrel and die temperature, until it reaches the requirements.
(4) in the extrusion process should be process requires periodic inspection of various process parameters are normal, and complete the process record sheet. Quality of the product quality inspection standard inspection profiles, identify problems and take timely solutions.
(1) stop feeding, plastic extruder burnishing the exposed screw, close the barrel and head the power to stop the heating.
(2) shut down the extruder and auxiliary power supply, so that the screw and auxiliary stop running.
(3) Open head flange connection, demolition nose. To clean up various parts of the porous plate and nose. Cleanup in order to prevent the application of steel law of residual material within the inner surface damage to the nose, the nose, steel clean up, worn out and then use sandpaper to adhere to the nose within the plastic, and lighting, painted with oil or silicone oil anti- rust.
(4) clean-up of the screw, barrel, remove the head, restart the host, plus parking material (or broken material), clean the screw and barrel, then screw selection of low-speed (sr / min or so) in order to reduce wear and tear. Be stopping material crushed into powder extruded with compressed air from the feeding port, exhaust port repeatedly blowing the residual pellets and powder, until the machine barrel is indeed no residual material down the screw speed to zero, stop the extrusion machine, turn off the total power and cold water valves.
(5) of the extrusion should pay attention to safety items: electricity, heat, mechanical rotation, and loading and unloading of heavy components. Extruder plant must be equipped with lifting equipment, assembly and disassembly bulky parts of the nose, screw, etc. to ensure safety in production.
Care and maintenance of the extruder
Screw extruder system routine maintenance and regular maintenance are two ways to carry out maintenance.
(A) routine maintenance is the regular routine work, not accounted for equipment operating hours, usually completed during the driving. Focus on a clean machine, lubricate all moving parts, easy to loose the thread fastening, timely check and adjust the motor, and control instruments, the working parts and piping.
(2) regular maintenance is generally in the extruder continuous operation of 2500-5000h machine downtime, the machine needs to disintegration of the inspection, measurement, identification of the main components of wear, replace reached the provisions of wear limits parts to repair damaged parts.
(3) does not allow empty running, so as not to screw and simply rolling the hair.
(4) when the operation of the extruder, the occurrence of abnormal sound, you should stop immediately, to check or repair.
(5) take strict precautions against metal or other debris from falling into the hopper, so as not to damage the screw and barrel. To prevent iron debris into the barrel, feeding the mouth of the barrel mounted suction magnetic components or magnetic material into the rack to prevent debris from falling into the material prior sifting.
(6) pay attention to the production of a clean environment, and not allow garbage contamination of material clogging the filter board, affecting the product yield, quality and increase the head resistance.
(7) When the extruder may take longer to stop using the work of the screw, Jane, nose coated with anti-rust grease. Small screw to be hoisted in the air or placed in special wooden boxes, and pieces of wood pad level, so as not to screw deformation or bumps.
(8) the periodic calibration of temperature control instruments, check the correctness of the regulation and control sensitivity.
(9) extruder gear box maintenance is the same as the general standard reducer. Is to check the gears, bearings and other wear and failure. Gearbox should use the lubricant specified by the machine instructions, in accordance with the provisions of the oil height by adding the oil, the oil is too small, lubrication is not reversed, the lower parts of life; oil too much, heat a large, energy, oil- deterioration, so that the same lubrication failure, resulting in the consequences of damage to parts. Gear box oil spill site should replace the gasket (circle), to ensure that the amount of lubricating oil.
(10) extruder, a subsidiary of the cooling pipe wall is easy to knot scale external corrosion rust. Maintenance should be done carefully check the scale too much can clog the pipeline to reach the cooling effect, corrosion and serious leaks, descaling and corrosion protection measures to cool in the maintenance must be taken.
(11) to focus on examination of DC motor drive screw rotating brush wear and exposure of the motor insulation resistance value above the specified value should be measured regularly. In addition, you want to check cables and other parts are rusty, and the use of protective measures.
(12) to designate a person responsible for equipment maintenance. Included in the plant equipment management file and every time to maintain detailed records of repair to