I. General Provisions

1. These specifications apply to the operation and management of vertical palletizers in fertilizer production workshops, covering the entire process of pre-production preparation, production operation, and maintenance.
2. Operators must pass training before taking up their posts. Before operation, they shall become familiar with the equipment structure and the contents of these specifications. Operators should have basic mechanical and electrical knowledge and be able to identify the main components of the equipment and common fault phenomena. Drinking alcohol within eight hours before the shift and during the shift is strictly prohibited. Labor protection articles must be worn as required.
3. The vertical palletizer mainly consists of a column frame, lifting mechanism (servo motor/hydraulic drive), gripper mechanism (mechanical clamping jaws/clamp/vacuum suction cups), pallet magazine, conveying system, electrical control system (PLC + touch screen), and safety protection devices (safety fence, guard door interlock, emergency stop button, area detection sensors), etc. The equipment uses a gripper to pick up packaged fertilizer bags from the conveyor line and stack them layer by layer onto pallets according to a preset stacking pattern. After palletizing is completed, the entire stack is moved out by forklift or conveyor system, realizing fully automated palletizing operations in the post-packaging stage.

II. Pre-Production Preparation Stage

2.1 Pre-Startup Inspection

1. Equipment integrity inspection: Check whether all parts are installed securely and whether fasteners are loose or fallen off. Check whether the gripper mechanism (clamping jaws, clamp, or suction cups) is worn, deformed, or damaged. Check the column guide rails and sliders for foreign matter and wear. Clear obstructions within the movement range of the palletizer and confirm that no unauthorized personnel are near the equipment.
2. Safety device inspection: Check whether the safety fence and guard door interlock device are intact, and whether the interlock is effective after the safety door is closed. Check whether the appearance of the emergency stop button is intact and whether it can immediately cut off power when pressed. Confirm that area detection sensors (safety light curtain, photoelectric switch) work normally. Safety protection devices must not be simplified or omitted. It is strictly prohibited to cross protective devices and enter the equipment movement area.
3. Air source inspection (pneumatic type): Open the main air source valve and check whether the air pressure is within the range of 0.5–0.7 MPa. Check whether the air pipes leak, whether the pneumatic FRL unit (filter, pressure reducing valve, lubricator) is normal, and drain the accumulated water in the water separator filter completely. The air source should be dry, oil-free, and water-free.
4. Lubrication system inspection: Check the lubrication condition of moving parts such as chains, guide rails, gear racks, and bearings. Replenish grease when insufficient. Check whether the reducer oil level is within the normal range.
5. Electrical inspection: Power connections should be firm and reliable, insulation should be good, and grounding should be correct. The three-phase power supply voltage fluctuation must not exceed ±10%. Check whether the wiring terminals in the control cabinet are loose and whether each switch is in the normal position.
6. Pallet and material inspection: Add sufficient empty pallets to the pallet magazine and confirm that the pallets are not deformed or damaged. Check whether the incoming packaging bags are intact. Broken bags or severely deformed packaging bags must not enter the palletizing station.
7. No-load trial run: Turn on the key switch on the operation box and confirm that all emergency stop switches have been released. In manual mode, test whether each actuator (lifting, gripping, rotating) operates normally, and confirm that the gripper position is accurate and free of jamming. Switch to low-speed automatic mode for no-load trial operation and observe whether the equipment runs smoothly and whether there is abnormal noise.

2.2 Material Preparation

1. Confirm that the weight and dimensions of the materials to be palletized (packaging bags) are consistent, with deviations within the allowable range. The material weight must not exceed the rated load of the equipment (the equipment load capacity should have a 20% margin).
2. Check the appearance of the packaging bags. Bags that are broken, leaking, or severely deformed must not enter the palletizing station, so as to prevent contamination of the equipment or instability of the stack.
3. According to the current production specification, verify whether the palletizing recipe (pallet size, layer pattern, number of layers, box arrangement) is set correctly.

3.1 Startup Sequence

1. Close the main power switch of the control cabinet and confirm that the emergency stop indicator light is on and the power indicator light is normal.
2. Open the main air source valve (pneumatic type) and confirm that the air pressure reaches the set value.
3. Turn on the key switch on the operation box and confirm that both emergency stop switches are released. At this time, the emergency stop indicator light goes out and the power indicator light is on.
4. On the touch screen interface, confirm that there is no alarm information and select or verify the current palletizing recipe.
5. After confirming that there are no people or debris within the working area of the palletizer, switch the equipment to low-speed automatic mode for trial operation. After confirming that the action sequence is correct, switch to normal-speed automatic operation.
6. Press the start button. The palletizer enters automatic operation, and the operation indicator light turns on.

3.2 Operation Monitoring

1. Palletizing quality monitoring:
   • Observe whether the palletizing position is accurate and whether there is offset. When the palletizing position is offset, first check whether the pallet is in place, then check whether the positioning sensor is blocked by dust, and finally check whether the servo origin is lost.
   • Check whether the stack pattern is neat and stable, and whether there are signs of misalignment or collapse. Layer pattern parameters (length, width, height, arrangement) must match the actual objects.
   • Observe whether the gripper picks up reliably and whether there is bag dropping. When a bag drops, check whether the air pressure is sufficient, whether the clamping jaws or suction cups are worn, and whether the material weight exceeds the rated range.
2. Operation status monitoring:
   • Listen for abnormal noise from the motor and reducer; observe whether the equipment runs with jamming or vibration.
   • Check whether the tension of chains and timing belts is appropriate, and whether the guide rails have abnormal noise.
   • Pay attention to alarm information on the touch screen and handle it promptly.
3. Sensor monitoring: Regularly check whether the surfaces of photoelectric switches, proximity switches, and other sensors are clean and free of dust and material obstruction. Abnormal sensor signals can cause failures such as bag identification failure and positioning deviation.
4. Safety discipline (red prohibitions):
   • During equipment operation or standby, it is not allowed to enter the operating range of the palletizer. Especially when the gripper is moving vertically, it is strictly prohibited to walk under the gripper.
   • Operators may only run the palletizer manually or automatically after confirming that no unauthorized personnel are near the palletizer.
   • It is strictly prohibited to attempt to block the movement of the palletizer with the body or tools. When the equipment must be stopped immediately, press the “Emergency Stop” button.
   • When it is necessary to inspect parts below the palletizer or enter the working range, the operator must confirm that the equipment emergency stop button has been pressed.

3.3 Shutdown Operation

1. Normal shutdown:
   • Confirm that the target palletizing quantity has been completed and stop upstream feeding.
   • After the current palletizing cycle is completed and the entire stack is palletized, turn the “Auto/Manual” switch to the “Manual” position.
   • Press the stop button on the operation box, and the equipment stops running.
   • Turn off the main power of the control cabinet, close the main air source valve (pneumatic type), remove the key, and keep it properly.
2. Emergency shutdown (abnormal shutdown): If any of the following conditions occurs, immediately press the emergency stop button or cut off power to perform emergency shutdown:
   • Personnel enter the dangerous area or a collision is about to occur.
   • The equipment exhibits unexpected movement, abnormal vibration, or impact noise.
   • Dangerous situations such as bag dropping, gripper loss of control, smoke/fire, etc. occur.
   • Dangerous situations occur where personal injury or mechanical injury to personnel is about to occur.
   • Handling after emergency shutdown: After eliminating the danger/fault cause, release the emergency stop button, confirm reset on the HMI, and ensure the status changes from red to green (ready). If necessary, return the robot to the origin or restart the palletizing program. Before the danger is eliminated, it is strictly prohibited to press confirm/reset on the HMI.
3. Post-shutdown on-site handling (mandatory):
   • Perform daily cleaning of the palletizer, and clean dust and material residue on the gripper, guide rails, and sensor surfaces.
   • Regularly clean the photoelectric switches and reflectors according to actual conditions.
   • Check whether moving parts such as grippers, suction cups, and clamping jaw rubber pads are loose or worn.
4. Shift-change shutdown requirements:
   • Before handover, the equipment must be stopped and cleaned, and the Equipment Operation Record and Shift Handover Record must be truthfully filled in, noting the equipment operation status during the shift (palletizing quantity, palletizing quality, abnormalities, and countermeasures).
   • Before startup, incoming shift personnel must re-confirm the equipment status against the inspection requirements in the “Pre-Production Preparation Stage.”

IV. Maintenance and Care

4.1 Daily Maintenance (Each Shift)

1. Cleaning: Clean dust and material residue on the equipment surface; clean dust on the surfaces of photoelectric switches and sensors.
2. Gripper inspection: Check whether grippers, suction cups, and clamping jaw rubber pads are loose or worn.
3. Safety devices: Check whether emergency stop buttons, safety door interlocks, and area detection sensors are normal.
4. Air source inspection: Check whether the air pressure is within the normal range and drain accumulated water in the water separator filter completely.
5. Inspection record: Record operating status, palletizing quality, alarm information, etc.

Regular Maintenance

1. Weekly maintenance:
   • Clean dust on the surfaces of photoelectric switches and sensors.
   • Check whether all fastening bolts are loose.
2. Monthly maintenance:
   • Add grease to moving parts such as chains, guide rails, and gear racks.
   • Check the tightness of belts/timing belts.
   • Check the oil level in the lubricator cup of the pneumatic FRL unit.
3. Quarterly maintenance:
   • Check the reducer oil level (change oil after the first 500 hours of operation).
   • Check whether the chain support has breakage or jamming.
   • Check whether the wiring terminals in the control cabinet are loose.
4. Annual maintenance:
   • Replace reducer lubricating oil.
   • Comprehensively inspect electrical components such as motors, contactors, and relays.
   • Check whether the mechanical structure is deformed and correct it if necessary.

4.3 Long-Term Shutdown Maintenance

When the equipment is out of service for more than 30 days, thoroughly clean the equipment and apply anti-rust grease to exposed rotating parts. Add lubricating oil to moving parts. If installed outdoors, cover the equipment with a rain cover. Before restarting, test the motor insulation with a megohmmeter, check whether safety devices are effective, trial run according to the no-load trial run requirements, and feed production only after confirming normal operation.

4.4 Fault Handling Principles

1. If abnormal conditions such as palletizing position offset, bag dropping, alarm shutdown, or abnormal vibration are found, stop immediately; restart only after the cause is identified and the fault is eliminated.
2. It is strictly prohibited to run equipment with faults, and strictly prohibited to perform maintenance or cleaning while the equipment is running.
3. When repairing transmission parts or entering the equipment movement area, cut off power, close the air source, hang a “Do Not Close Switch” warning sign, and implement the Lockout/Tagout (LOTO) procedure.

V. Common Faults and Remedies