How to prevent the leakage of fresh-keeping gas in modified atmosphere packaging

Small leaks, big problems Everyone knows that leaks in modified atmosphere packaging (MAP) are bad news. Even small leaks can cause huge damage. In a package with a specific oxygen ratio, even a small hole half the diameter of a human hair can allow oxygen in the air to quickly enter the package.

First of all, let's review the oxygen concentration of modified atmosphere packaging for different products:

Raw Red Meat - Oxygen concentration above 70% is required to keep the flesh red during the shelf life

Cooked food, bakery, high-fat snack food, etc. - the oxygen concentration must be kept within 1% to guarantee the shelf life

Fresh fruits and vegetables - the oxygen concentration should be maintained at about 5% to ensure a low respiration rate and achieve the due shelf life

However, as long as there is a leak in the packaging, within three days, the oxygen content will be high enough to allow germs such as bacteria and mold to grow, rendering the shelf life meaningless, or reducing the high concentration of oxygen in the original packaging to air levels, Endangering brand reputation and even causing food safety issues.

Leak point testing Leak testing is a critical step in the quality control of modified atmosphere packaging, with regard to how fast air can enter a leaking package? The following is the leak test of Zhejiang Mingwei.

If an initial modified atmosphere packaging product with an oxygen concentration of 0.1 %. We punched different sized holes in the packaging cover film and measured how long it took for oxygen to enter the packaging from the surrounding air:

With a hole just 50 microns in diameter (roughly half the diameter of a human hair), it would take about 70 hours for the oxygen content in the package to reach 10 percent, a level at which microbes such as mold and bacteria can thrive. Usually the sales flow of products, 70 hours is the time from the factory to the supermarket shelves. In other words, even with such a tiny leak, the shelf life of the product will definitely be shortened considerably.

With a 100-micron diameter hole (one tenth of a millimeter), we found that in less than a week, the oxygen content in the package would approach air levels (20.9%).

Leaks mean shorter shelf life If a leaked package is on a supermarket shelf, this can have serious consequences:

Shortened shelf life - may be from months to weeks or even days

Customer complaints about product quality

Product recycling loss

direct damage to the brand

We want to tell customers who are engaged in modified atmosphere packaging products: Oxygen is a key factor affecting the shelf life of products. There are many sources of leakage in modified atmosphere packaging:

False seal caused by material clamping at the seal, oil stains on the edge of the tray seal, etc.

Leakage caused by heat sealing temperature and sealing quality of packaging machine

There are trachoma in the packaging materials that are difficult to identify with the naked eye.

As we realize the serious hazard of leakage to the shelf life of modified atmosphere packaging, it is especially important that we conduct an effective test of the packaging for sealing before the packaging leaves the production facility.

Inadequacy of traditional water bath leak detection We believe that in the traditional food manufacturing industry, packaging tightness testing is not a new topic, and there should be a lot of detection methods using water bath method (quality control personnel put the packaging into a test container full of water, A vacuum is applied above the liquid level to expand the package of the product immersed in the water, and if there is a leak, the package will show continuous blisters), however:

Visual inspection is too subjective, employee A may find the leak, but employee B may not

Products that have been tested you will have to throw away the packaging, even the product

Hygiene issues, introducing water into food in-house is not a good idea

It can only do random inspection, and cannot cover the whole batch of products 100%

A better leak detection technology for modified atmosphere packaging came into being: because we know that when it comes to modified atmosphere packaging, there is a gas in it that is indispensable, and that is carbon dioxide. **[modified atmosphere packaging for cold fresh meat (contains about 20% CO2); modified atmosphere packaging for cooked food and braised food (contains about 30% CO2); modified atmosphere packaging for fruits and vegetables (contains 5-8% CO2) ]**

The carbon dioxide test method uses CO2 as a tracer gas for non-destructive online 100% inspection: the finished product of the modified atmosphere package is put into a sealed chamber after being connected to the line, and the chamber is evacuated. If the package leaks, the gas in the package will be removed. Withdraw into the chamber. The sensor will collect the carbon dioxide leaked from the packaging, and the carbon dioxide concentration under unit time and pressure is used to judge whether your packaging is leaking, and the back end will reject unqualified products.

Zhejiang Mingwei Modified Atmosphere Packaging Machine solves the preservation solution for you.