How Does The Vacuum Packaging Machine Keep Products Fresh?

How does the vacuum packaging machine keep products fresh?

Nowadays, more and more people are using vacuum packaging machines to package their products. Products packaged in vacuum packaging machines not only have a long shelf life but also maintain their original color, aroma, and flavor. Modern people's diverse lifestyles bring a wealth of convenience and enjoyment. How do vacuum packaging machines preserve product freshness? Below, I will briefly explain the working principle, workflow, and features of vacuum packaging machines, so that more people can understand how vacuum packaging machines serve consumers.

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Working Principle: A vacuum packaging machine consists of five main parts: an upper chamber, a lower chamber, a machine body, an electrical system, and a vacuum system. A sealing device is installed on the top of the upper chamber. The heating element, a nickel-chromium strip, is mounted on a bakelite-lacquered hot press frame, insulated from the chamber. The bakelite hot press is tightly attached to the airbag, creating a low vacuum state. When hot air is applied, the airbag is connected to the atmosphere through the heat-sealing solenoid valve yv2, creating a pressure differential. This increases the airbag volume, causing the heating head (nickel-chromium strip 10) to press downward, sealing and heating simultaneously. The heating temperature and time are adjustable.

Workflow:

1. Vacuum: The vacuum chamber lid is closed, the vacuum pump operates, and the chamber begins to evacuate. The bag interior is also evacuated, and the vacuum gauge needle rises. Once the rated vacuum level is reached (controlled by the time relay ISJ), the vacuum pump stops, and the vacuum is stopped. Simultaneously, the two-position, three-way solenoid valve IDT activates, evacuating the heat sealing chamber while the heat press frame remains in place.

2. Heat Sealing: The IDT opens, allowing ambient air to enter the heat sealing chamber through its upper air inlet. The pressure difference between the vacuum chamber and the heat sealing chamber inflates the heat sealing chamber, causing the upper heat press frame to move downward, pressing against the bag opening. Simultaneously, the heat sealing transformer activates, initiating sealing. Simultaneously, the time relay 2SJ activates, and after a few seconds, heat sealing is complete.

3. Air Return: The two-position, two-way solenoid valve 2DT opens, allowing atmospheric air to enter the vacuum chamber. The vacuum gauge needle returns to zero, the heat press frame resets via the return spring, and the vacuum chamber lid opens.

Features:

1. It removes some air (oxygen) from the packaging container, effectively preventing food spoilage.

2. Using packaging materials with excellent barrier (airtightness) properties and strict sealing techniques and requirements effectively prevents the exchange of packaged contents, thus preventing weight loss, flavor loss, and secondary contamination.

3. The gas inside the vacuum packaging container is removed, accelerating heat conduction, which improves the efficiency of heat sterilization and prevents the packaging container from rupturing due to gas expansion during heat sterilization.