When selecting a vacuum liquid packaging machine, the appropriate model should be determined according to bag size, liquid content, and vacuum requirements. Maintenance should focus on the vacuum pump, including replacement of the exhaust filter, vacuum pump oil, and oil filter, as well as regular cleaning and oil changes.
1. Purchase Considerations
Selection by bag size
When vacuum packaging food, the machine should be selected according to the packaging bag dimensions. Small bags can be handled by compact, flexible small models, while large bags require a larger vacuum chamber and stronger vacuum capability to ensure packaging quality and efficiency.
Selection by liquid content
For liquid products, the double-chamber vacuum packaging machine is a commonly used general-purpose model. To prevent liquid overflow during vacuuming, the working platform is often made in a recessed form so that the product remains slightly tilted inside the vacuum chamber. The recess depth and shape can be adjusted according to the product. For such recessed platforms, positioning blocks, and related support parts, Hansheng Automation provides non-standard custom machining according to customer requirements, supporting equipment to meet different liquid packaging process needs.
Selection by vacuum requirements
When products are intended for export or have higher quality requirements, stricter demands are placed on vacuum level, pumping speed, and sealing stability. In such cases, thorough communication with the equipment manufacturer's technical personnel is necessary, and a dedicated model may be customized to meet the specific vacuum packaging requirements.
2. Maintenance Considerations
Exhaust filter replacement
If the pump temperature rises significantly, the motor current reaches or exceeds the rated value, or oil mist appears at the exhaust port, the exhaust filter may be clogged. A clogged filter affects pump exhaust, causing internal pressure and temperature to rise. The exhaust filter should be inspected and replaced promptly when these signs appear.
Vacuum pump oil and oil filter replacement
When the vacuum pump oil becomes contaminated, blackened, or thickened, it should be replaced. Contaminated oil reduces lubrication and sealing performance, lowers vacuum level, and may damage the pump. The oil filter should be replaced at the same time, and the pump should be cleaned before adding new oil.
Cleaning and oil change procedure
Stop the pump and drain the hot oil. Tighten the drain plug, run the pump for 5–10 seconds, and drain the remaining oil completely. Add cleaning oil to about 3/4 of the oil sight glass height, and run the vacuum pump for 5–10 minutes. Stop the pump and drain the oil until it appears transparent. Tighten the drain plug and run the pump again for 5–10 seconds to drain all remaining oil, then fill with the specified new oil. After filling, the oil level should be maintained between 1/2 and 3/4 of the oil sight glass height, and the oil level and contamination should be checked regularly.
Shortened oil change interval
When packaging liquid products, water vapor content is relatively high and can mix into the vacuum pump oil, reducing oil quality. Therefore, the oil change interval should be shorter than that for ordinary products. If oil contamination is found, it should be replaced immediately to maintain a high vacuum level and extend the service life of the vacuum pump.
