1、 Daily maintenance (before and after each use/daily)

Belonging to high-frequency basic maintenance, the core is to avoid adhesive solidification and blockage, timely clean impurities, ensure normal operation every time the machine is turned on, with no fixed "cycle duration" and "frequency of use" as the trigger node.

Pre-start inspection

Confirm that there are no residual solidified rubber blocks in the flow channels of the pump body, hose, nozzle, etc. (especially for equipment that has not been cleaned in a timely manner after shutdown, solidified rubber may block gears or valves).

Check if the lubricating oil level of the drive motor and reducer is normal, and if there are any abnormalities such as abnormal noise or leakage.

Confirm that the model of hot melt adhesive is compatible with the pump body (if high viscosity adhesive needs to be matched with a high torque pump to avoid motor overload), and that the adhesive material is free of impurities and clumps.

Cleaning after shutdown

Before the rubber material is fully cured (usually within 10-30 minutes after shutdown), a special scraper and solvent (such as ethyl acetate, which should meet the characteristics of the rubber material) must be used to clean the residual rubber material on the inlet and outlet of the pump body and the surface of the gear to prevent adhesion of the gear after curing, which may cause jamming or damage during the next startup.

After turning off the power, check whether the pump body seals (such as O-rings and mechanical seals) are worn or deformed. If there is glue leakage, they should be replaced in a timely manner.

2、 Regular maintenance (fixed cycle, divided by usage intensity)

1. Short term regular maintenance (weekly monthly, suitable for high-frequency scenarios where continuous use for more than 4 hours per day)

The key is to investigate the wear and tear of vulnerable parts, lubrication status, and equipment operation stability, in order to avoid the accumulation of small problems leading to malfunctions.

Lubrication system inspection: Supplement special lubricating oil (select the model according to the equipment manual, such as lithium based grease) to the moving parts such as drive gears and bearings, remove impurities from the old oil, and prevent dry friction and wear.

Inspection of vulnerable parts:

Check if the meshing clearance between the driving gear and the driven gear of the gear pump has increased (normal clearance ≤ 0.1mm, excessive clearance can easily lead to unstable adhesive output);

Check if the feed filter screen (if any) is clogged (impurities can cause insufficient feed and the pump body to overheat due to idling), and promptly disassemble, clean or replace the filter screen.

Sealing performance testing: During operation, observe whether there is glue leakage in the pump body joints and shaft ends. If there is, replace the seals (the seal life is usually 1-3 months, and the replacement cycle needs to be shortened under high-frequency use).

2. Long term regular maintenance (every 3-6 months, suitable for all scenarios, especially equipment used in high-frequency/harsh environments)

Belonging to deep maintenance, it is necessary to dismantle core components, investigate wear and aging issues, and extend the overall lifespan of the equipment.

Disassembly and maintenance of pump body: Disassemble core components such as gears, shaft sleeves, bearings, etc., clean them with specialized cleaning agents (avoid using corrosive solvents), check the surface of the parts for scratches, wear, or corrosion (such as acidic components in the rubber material that may corrode metal parts), and replace spare parts if the wear is severe.

Drive system maintenance: Check the insulation of the motor winding (measure the insulation resistance with a multimeter, which should be ≥ 0.5M Ω), and clean the dust inside the motor; Check the meshing status of the gearbox gears and replenish or replace the gearbox lubricating oil.

Overall calibration: After assembly, start the machine and test the accuracy of the adhesive output (if a fixed flow rate is set, use weighing method to detect the deviation between the actual output and the set value. If the deviation exceeds ± 5%, adjust the gear clearance or replace the pump core).

3、 Maintenance cycle adjustment in special scenarios

Influence of rubber properties

If high viscosity hot melt adhesive containing fillers (such as fiberglass and calcium carbonate) is used, the adhesive will wear and clog the gears and filters faster. Therefore, it is necessary to shorten the daily cleaning (such as cleaning the filter after each shutdown) and short-term maintenance cycle (such as checking gear wear every 2 weeks).

If using low-temperature curing adhesive, the curing speed is fast after shutdown, and residual adhesive cleaning should be completed within 5-10 minutes after shutdown to avoid channel blockage.

Impact of work environment

If the equipment is used in an environment with high dust and temperature (such as workshop temperature>40 ℃), the motor and bearings are prone to overheating and aging. It is necessary to check the motor temperature monthly (not exceeding 70 ℃ during operation), clean the surface and internal dust of the equipment every 2 weeks, and shorten the long-term maintenance cycle to 3 months.

Frequency of use impact

If the equipment is used intermittently (such as 1-2 hours per day), short-term maintenance can be extended to once a month, and long-term maintenance can be extended to 6-12 months, but residual glue and lubrication status must be thoroughly checked before each start-up.

4、 Key precautions

During maintenance, it is necessary to cut off power and cool down (the temperature of the pump body should be reduced to below 50 ℃) to avoid burns or electrical accidents.

When replacing spare parts (such as gears and seals), original equipment accessories should be used to avoid leakage or decreased accuracy due to size mismatch.

Establish a maintenance record ledger to record the time, content, replacement parts, and equipment operation status of each maintenance, in order to trace the cause of faults and develop personalized maintenance plans.

In summary, the maintenance of hot melt adhesive pumps needs to be tailored to local conditions. The core principle is to shorten the cycle under high-frequency use and harsh working conditions, and extend it appropriately under low-frequency use and mild working conditions. However, daily cleaning and pre startup inspection cannot be omitted to ensure stable operation of the equipment and extend its service life.