Preparation and inspection before startup: First, it is necessary to inspect the bolts and nuts of each part of the spraying machine, as well as all pipeline connectors (including the connecting nuts and hose clamps of the suction system), one by one, to ensure that they are all tightened correctly. At the same time, carefully familiarize yourself with the switching directions of each air circuit gate valve, and clarify the rotation rules of the pressure regulating valve and the drain valve (where the pressure regulating valve handwheel rotates clockwise to increase pressure and counterclockwise to decrease pressure). In addition, the capacity of the equipped air compressor should not be too small, and the length of the air hose used should not exceed 5 meters.
Pressure regulation and air source connection: Insert the paint suction tube and the drain valve together into the thinner bucket, and connect to the compressed air source. Adjust the inlet pressure reasonably according to the specific type of paint used; to ensure operational safety, the maximum inlet pressure should not exceed 0.6 MPa, and the inlet pressure should be adjusted to the lowest possible level while ensuring good paint atomization effect.
No-load commissioning and startup preparation: Open the drain valve (do not open the spray gun yet). At this point, the pneumatic hydraulic booster pump of the spraying machine will start to perform continuous and stable reciprocating motion. After the paint hydraulic system of the spraying machine circulates under no-load pressure conditions for 2 to 3 minutes, close the drain valve. If the pressure of the paint hydraulic system tends to balance, and the pneumatic hydraulic pump can automatically balance and remain stationary, it indicates that the equipment commissioning is normal and the spraying operation can proceed.
Spraying operation specifications: When spraying, the direction of the handheld spray gun should be perpendicular to the surface of the workpiece being coated, or slightly tilted at a certain angle. The movement direction of the spray gun needs to be parallel to the surface being coated. The movement speed should be uniform, with the appropriate standard being to avoid paint sagging, ensuring uniform spraying thickness and smooth surface.
Paint pretreatment requirements: The paint used for spraying must be kept clean. For paint containing impurities and not sufficiently clean, a 40~100 mesh filter screen should be selected according to the particle size and viscosity of the paint, and then the paint should be filtered before spraying. If the paint is newly unsealed and clean without impurities such as paint skin or sand particles, it only needs to be fully stirred evenly and does not require filtering. For paint prone to sedimentation, the paint should be continuously stirred throughout the spraying process to prevent sedimentation from affecting the spraying effect.
Safety precautions during spraying: During spraying operations, if it is necessary to clean or replace the spray nozzle, or temporarily stop spraying, the trigger safety lock of the spray gun should be engaged promptly. Under no circumstances should the muzzle of the spray gun be aimed at yourself or others, to prevent accidental triggering and the ejection of high-pressure paint, which could cause bodily injury. If the spray gun can still be fired even after the trigger safety lock is engaged, adjustments should be made by calibrating the small nut at the end of the valve core pull pin. If the spray nozzle becomes blocked, it should be soaked in the corresponding solvent for cleaning, or gently removed of dirt with a brush. It is strictly prohibited to use hard objects to randomly poke or stir, as this could damage the spray nozzle.
Usage specifications for rotary nozzles: If a rotary nozzle is used during spraying, when the nozzle becomes slightly clogged, rotate the nozzle handle 180 degrees, pull the trigger of the spray gun, and use the hydraulic pressure of the high-pressure paint to blow out the dirt inside the nozzle. If the nozzle is completely clogged, slightly loosen the nozzle connecting nut first, wait for the paint to depressurize, and then rotate the handle. It is strictly prohibited to forcefully pull the handle without depressurizing, as this may easily damage the handle. Whether using a standard nozzle or a rotary nozzle, a sealing ring must be placed at the connection with the spray gun outlet to prevent paint leakage.
Long-term equipment maintenance: If the spraying machine operates continuously for an extended period, resulting in severe "frost accumulation" inside and outside the muffler, a water separator and air filter, as well as an air dryer, can be installed before the compressed air is fed into the spraying machine. Alternatively, the muffler can be dismantled. Furthermore, the engine oil in the oil cup of the oil mist device can be replaced with antifreeze for automobile radiators to alleviate the frost accumulation issue. It should be noted that the water separator, air filter, and air dryer need to be purchased or made by the user according to their actual usage needs, while antifreeze for automobile radiators can be easily purchased in local markets.
Post-spraying treatment: After the spraying operation is completed, or when a certain interval is required before continuing the spraying, it is necessary to promptly remove the paint suction tube from the paint bucket and allow the sprayer to run in idle mode, thoroughly discharging the residual paint from the interior of the paint pump, suction tube, high-pressure hose, and spray gun. Subsequently, pour in diluent or corresponding solvent and allow the equipment to continue running in idle mode, thoroughly cleaning all hydraulic circuits of the paint, including the interior of the paint pump, suction tube, drain valve, high-pressure hose, airless spray gun, and spray nozzle. During the cleaning process, the inlet ball valve should be turned down, and the reciprocating motion of the sprayer should be controlled at 30 to 40 times per minute to ensure thorough cleaning without damaging the equipment.
English
