1.1 production and operation sequence of extruder+s first train
For some reasons, the extruder has been shut down for a period of time, and now it needs to be started for production. The operation sequence is as follows:
① Clean up the environmental sanitation of extruder production line equipment.
② Clean the dust on the equipment and clean the equipment.
③ Check whether the connecting bolts of all parts are loose and fasten them properly as appropriate.
④ Clean the dust in the control electric box and instrument box; check whether the connection of each line is tight; conduct power transmission test to check the insulation resistance of the motor, electric heating device and electric control part, which shall meet the relevant regulations.
⑤ . pull the V-belt pulley, and the screw shall rotate easily and flexibly without blocking.
⑥ Check the quality of raw materials for production (verify whether the number plate of the materials is consistent with the process requirements; whether the particles are uniform; whether there are impurities in the materials; whether the materials are wet, etc.).
⑦ Heating up of barrel and mould. After reaching the process temperature, the heating temperature shall be constant, and the time shall not be less than 1.5h.
⑧ Check and test the feeding device, and fill the hopper with raw materials.
⑨ . pull the V-belt pulley again, it should be easy and flexible without blocking.
⑩ Start the working motor of driving screw at low speed, and observe whether the pointer of voltage and current meter swings normally; start feeding when there is no abnormal phenomenon.
⑪ . feed into the barrel. Feed less and even materials at the initial stage of production. Observe the swing of ammeter pointer at the same time. It should be within the allowable rated value (allowing instantaneous overload).
⑫ . start the screw drive motor at low speed.
1.2 handling of abnormal faults in production
During the normal production and operation of extruder, sometimes there is a sudden failure of power failure or metal foreign matter entering the barrel, which makes the screw stop rotating suddenly. At this time, the treatment method is as follows:
① Immediately turn off the power supply of each motor, electric heating and feeding system, and disconnect or reset each control knob to the zero position.
② . PVC raw materials are added into the barrel, which means that the screw cannot rotate due to metal foreign matters in the barrel. In this case, the barrel cooling fan shall be started immediately to cool down the barrel; the molding mould shall be dismantled immediately and the screw shall be withdrawn; the sticky materials on the mould, barrel and screw shall be removed, and the screw and molding mould shall be installed after the failure factors are eliminated; the screw and molding mould shall be reheated and heated again to prepare for continuous production 。
1.3 precautions for operators in extruder operation
① Before starting the extruder for production, carefully check whether there are foreign matters in the barrel and hopper, and timely remove all foreign matters and oil stains.
② . in case of any abnormal sound or unstable operation of the production equipment, and if you don+t know the cause of the fault, you should stop the machine in time and find the relevant personnel to solve it. It is not allowed to repair the equipment during the start-up and operation of the equipment, and it is not allowed to touch the transmission parts by hand.
③ When disassembling and installing the screw and the parts in the forming mould, it is not allowed to directly knock the parts with a heavy hammer. If necessary, it is necessary to pad hardwood and then knock the disassembly and installation parts.
④ If there is no production material in the barrel, the screw is not allowed to rotate for a long time in the barrel, and the maximum idling time shall not exceed 3min.
⑤ In case of any fault in the production process of extruder, the operator shall not face the barrel or the molding die mouth when troubleshooting, so as to prevent the molten material in the barrel from spraying and injuring people.
⑥ During the normal production process of extruder, it is also necessary to observe the swing change of the pointer of the main ammeter. In case of long-term overload, it is necessary to stop the extruder in time, find out the cause of the fault and eliminate it before continuing the production.
⑦ . when checking the working temperature of axis and motor shell, gently touch the testing part with the back of hand.
⑧ . when cleaning the sticky materials on the barrel, screw and mould, the bamboo or copper knife must be used for cleaning. It is not allowed to scrape the materials with steel knife or barbecue the scraps on the parts with fire.
⑨ During extrusion production, operators are not allowed to leave their posts to do other work. When they have to leave their posts, they should stop or find someone to take care of them.
⑩ It is not allowed to let the untrained replace the formal operators to operate the production independently.
⑪ . if the cleaned screw is not used temporarily, it shall be coated with a layer of antirust oil, wrapped and hung vertically in a dry and ventilated place.
⑫ For the extruder that has not been used for a long time, all working aspects of the forming die shall be coated with antirust oil, and the inlet and outlet shall be sealed with oil paper. No heavy objects shall be stacked on the barrel and mould to avoid long-term compression and deformation.
⑬ The lubricating oil in each mailbox and oil cup shall be replaced for all equipment on the extruder production line newly put into production 500 hours after commissioning. All bearings, oil cups, oil tanks and oil pipelines shall be drained of the original lubricating oil and cleaned. Then add enough new lubricating oil.
Note: coextrusion die is used for coextrusion unit, the principle is the same.