Large-scale failures often cause great losses, and only regular maintenance and maintenance in strict accordance with the rules and procedures can prevent them from happening.
Specifications for repair, maintenance and use of blow molding machines
1. Inspection of Machine Assembly If the extrusion blow molding unit is newly purchased, the inspection of machine assembly should be carried out. After the equipment is installed according to the requirements of the manual, the entire unit should be calibrated, including the alignment of the extruder head and the clamping device; install the mold water cooling pipe and check whether the direction is correct; the operator and the control device (electrical control box, Whether the programmable controller, operating keyboard, etc.) is convenient in operation; whether the feeding, the placement of finished products, and the recycling process of waste products are smooth without affecting normal operation, and whether the location of relevant auxiliary equipment is appropriate, etc. Only after the inspection results of the equipment assembly meet the production and safety requirements, the equipment is in the best assembled state.
2. Inspection of hydraulic and lubrication system Check the hydraulic oil level gauge of the extruder and each hydraulic device to keep the oil level of the oil tank above the reference oil level.
3. The preparatory work before starting the machine is as follows.
1) The materials used for extrusion blow molding should meet the required drying requirements, and further drying is required if necessary.
2) According to the variety and size of the product, select the machine head specification, and install the machine head in the following order: the head flange, the mold body, the die, the porous plate and the filter screen.
3) Connect the compressed air pipe, install the core mold electric heating rod and the head heating ring. Check and turn on the water system. Adjust the gap of the die to be uniform, and check whether the centerline of the main machine and the auxiliary machine is aligned.
4) Start the extruder, clamping device, manipulator and other operating equipment to perform no-load operation, check whether each safety emergency device is operating normally, and remove the fault in time.
5) According to the regulations of the process conditions, set the temperature of the extruder head and each heating section and perform heating section by section, and use the scraps to test the integrity of each heating section to check whether there is no heating phenomenon; wait until the temperature of each section reaches the set point After the temperature is maintained, the temperature is maintained for 0.5 to 1 h.
6) On the programmable controller, set the thickness of the parison wall at each point according to the process regulations.
7) The outer layer is generally opened first when the material is turned on, so as to prevent the material from flowing back from the outer layer due to excessive pressure after the inner layer is opened. The blanking flow frequency is increased step by step from small to large to prevent the opening frequency from being too large, which will cause the screw and screw to be twisted due to low temperature.
8) Process conditions:
a. When the raw material is plasticized and melted, the process temperature should be controlled within the range of 170-230 °C.
b. The inflation ratio of the blank tube blow-molded bottle product is controlled within the range of (1.5-3):l.
c. The pressure of the compressed air used for forming the bottle product by the inflation tube is 0.3-0.6MPa.
d. The temperature of the mold for forming the bottle is 20-50 ℃, and the cooling and shaping time accounts for about 50% to 60% of the total time of the product opening production cycle.
4. Precautions for shutdown: when the machine is shut down, the speed is reset to zero, and each heating section is closed one by one; the mold is closed, and the blowing needle is half a centimeter away from the mold to prevent hard objects from falling into the mold and causing damage to the mold; Apply rust inhibitor. Turn off the main power supply, lubricate and maintain the equipment, add lubricating oil, clean the whole machine, and close the water in each part; if the downtime is long, the water inside the mold must be drained to prevent rust and blockage.
5. In order to prevent personal accidental injury, all the transmission parts of the machine should be equipped with safety shields and safety gratings; there should be safety doors at the product demolding outlet; the heating area of the machine should have safety and thermal protection shields; Steel falls, and operators are prohibited from reaching into the machine; emergency brake buttons and alarms should be installed in key parts of the equipment; all pressurized containers should be regularly tested for hydraulic pressure. During the molding operation, if there are more than two people, the division of labor must be clearly defined; when the equipment or mold is unloaded, the power supply and gas source should be cut off, and a "maintenance" sign should be hung at the repair place; during the production of large containers, due to the mold cavity In order to prevent the human body from entering the mold cavity, protective measures should be installed to prevent the human body from entering the mold cavity, and protective measures should be installed to prevent the mold from being closed when the door is not closed. When the car is cold, the operator cannot stand under the machine head to prevent the overheated melt from splashing and hurting people; when the material is crushed, cut off the power and remember to open the cover for maintenance.
6. Daily maintenance and use of blow molding machine
1) Before starting each shift, lubricating oil must be added to each moving part. (manipulator, manipulator guide rail, mold opening and closing guide rail)
2) The swing arm can be added once every (3-4) days. The large chain and small chain of the heating machine can be used once a month. Always check whether the main engine reducer and the heating machine reducer are short of oil. The main engine bearing can be added once (2-3) months. Before production, check whether the moving parts are firm, whether the screws are loose and fall off, especially if the impact force is strong, and whether the belt transmission part is abnormal.
3) Check whether the high-pressure air source, low-pressure air source, power supply, and water source are normal.
4) Check whether each emergency stop switch, safety door switch and protection device detection switch are normal.
6. Check whether the heating head enters the embryo and the part that drops the embryo works normally. If the embryo is not in place, the nut of the pressing device can be adjusted.
5) Check whether the lamp tube is damaged or broken. To be replaced in time.
6) Check whether each pneumatic component is leaking and whether the action is sensitive.
7) Check whether the triplet is abnormally leaking, whether it is blocked, and whether the water tank is too full.
8) When the solenoid valve of the blow molding machine is abnormal, it should be cleaned in time.
9) Blow moulds must be cleaned and polished regularly.
10) When opening the high and low pressure air source switch, you must move slowly to prevent the air source from blowing too fast and dirt to blow into the solenoid valve. At the same time, open the exhaust valve for 30 seconds to ensure that the air is clean.
11) When the machine is started, it must be confirmed that the mechanical parts are in good condition, there is no one inside the machine, and there is no foreign matter. Especially the crank handle and mechanical movement position, so as not to hurt people. Also close the safety door.
12) When starting the machine, the motor must be started first, and the heating machine must be started after a delay of 30 seconds to prevent voltage fluctuations. Make sure the cooling water is turned on before starting the heating.
13) After (2-3) minutes after the heating starts, wait for the oven temperature to rise evenly, and then press the embryo button. At the same time, the blowing bottle must be turned on when the power is turned on, otherwise there will be no blowing action.
14) When the machine is running, it is necessary to pay close attention to whether there is abnormal noise in the machine. It is necessary to detect it early and stop it in time to solve it.
15) In case of emergency, you can press the emergency stop button to brake in an emergency. Then analyze the cause of the formation according to the on-site situation, find the problem and solve it quickly.
16) After the machine is running normally, do not put any part of your body into the machine to avoid hurting people. If the machine has abnormal noise, it can be observed after slowing down.
17) After the normal production of the machine, the operator must always observe the quality of the bottle, so as not to affect the quality of the blowing bottle due to voltage fluctuations or other reasons.
18) When the machine is being repaired, you can press the fault repair button on the screen and post a safety notice to ensure safe repair. If you need to manually observe the movement of each cavity individually, pay attention to the position of the robot. At the same time, be sure to understand the role of the individual buttons, and then in the action. Make sure not to cause unnecessary trouble due to misoperation.
19) After each maintenance of the blow molding machine, be sure to clean up tools and screws, etc., so as not to be left in the machine and affect the normal operation of the machine.