Vacuum packaging is packaging that protects products from environmental contamination and extends the shelf life of food and other products, increasing their value and quality. Vacuum packaging technology originated in the 1940s. Since 1950, polyester and polyethylene plastic films have been successfully used in the packaging of goods, vacuum packaging machines have been rapidly developed.

A wide range of plastic vacuum packaging abounds in people’s lives and workplaces. Lightweight, airtight, fresh, anti-corrosion and rust-proof plastic vacuum packaging is used in a wide range of applications, from food to pharmaceuticals and knitwear, from precision product manufacturing to metalworking plants and laboratories. The growing use of plastic vacuum packaging has driven the development of plastic vacuum packaging machines and has placed higher demands on them.

The mechanism of vacuum packaging: its purpose is to reduce the oxygen content of the package, to prevent mold and rot of packaged food, to maintain the colour and flavor of food, and to extend the shelf life.

Vacuum inflatable packaging in the vacuum and then filled with nitrogen, carbon dioxide, oxygen, a single gas or a mixture of two or three gases. Its nitrogen is an inert gas, filling the role of the bag to maintain positive pressure, to prevent the air outside the bag into the bag, the food to play a protective role. Its carbon dioxide can be dissolved in various types of fat or water, leading to a weak acidic carbonic acid, which has the activity of inhibiting microorganisms such as moulds and spoilage bacteria. Its oxygen has the ability to inhibit the growth and reproduction of anaerobic bacteria, keeping the freshness and colour of fruits and vegetables, and high concentrations of oxygen can make fresh meat keep its bright red colour. The freshness of the fruit and vegetables but the nutrition is not lost.

One of the important aspects of vacuum packaging is the removal of oxygen, which helps to prevent food spoilage, and its principle is relatively simple, because food mould deterioration is mainly caused by the activities of micro-organisms, and most micro-organisms (such as mould and yeast) need oxygen to survive, and vacuum packaging is the use of this principle, the bag and the food cells within the oxygen pumped away, so that micro-organisms lose ” living environment”. Experimental evidence: when the concentration of oxygen in the bag ≤ 1%, the growth and reproduction rate of microorganisms will drop sharply, oxygen concentration ≤ 0.5%, most microorganisms will be inhibited and stop reproducing. (Note: vacuum packaging can not inhibit the reproduction of anaerobic bacteria and enzymatic reactions caused by food deterioration and discolouration, so it is also necessary to combine with other auxiliary methods, such as refrigeration, freezing, dehydration, high temperature sterilization, irradiation sterilization, microwave sterilization, salt pickling, etc..

In addition to inhibiting the growth and reproduction of micro-organisms, another important function of vacuum de-oxygenation is to prevent oxidation of food, as fats and oils contain a large amount of unsaturated fatty acids, which are oxidised by the action of oxygen, causing the food to become tasteless and spoiled. In addition, oxidation causes the loss of vitamin A and vitamin C. Unstable substances in food colouring are affected by the action of oxygen, causing the colour to darken. Therefore, oxygen removal can effectively prevent food spoilage and maintain its colour, aroma, taste and nutritional value.

A variant of vacuum packaging is inflatable packaging. The main role of inflatable packaging in addition to the vacuum packaging has the function of oxygen preservation, there are mainly anti-pressure, gas barrier, freshness, etc., can more effectively make the food long-term to maintain the original colour, fragrance, taste, shape and nutritional value. In addition, there are many foods that are not suitable for vacuum packaging, but must be used inflatable packaging. Such as brittle and fragile food, easy to caking food, easy to deformation away from the oil food, sharp edges or high hardness will pierce the bag of food, etc.. Food by the food vacuum packaging machine pumping packaging, filled with some gas, so that the inflatable pressure inside the bag is greater than the atmospheric pressure outside the bag, can effectively prevent the food pressure broken deformation, and does not affect the appearance of the bag and printing and decoration.

Inflatable packaging in the vacuum and then filled with a single gas such as nitrogen, carbon dioxide, rare gases or a mixture of 2-3 gases. Nitrogen is a chemically stable gas, which protects the goods from oxidation and other external disturbances, and keeps the bag under positive pressure to prevent the packaging from being flattened to the point of damage to the goods. Carbon dioxide can dissolve in various types of fat or water to form a less acidic carbonic acid, which has the activity to inhibit micro-organisms such as mould and spoilage bacteria. The principle of rare gases is similar to that of nitrogen.

Vacuum packaging machine variety, in the selection should focus on the following factors.

When purchasing, packaging solids, granules and other dry and non-corrosive materials, you can choose aluminum alloy, while packaging with soup, salt, acid composition of high materials, you can choose stainless steel or aluminum-magnesium alloy material. The sealing ring is generally made of silicone rubber, black rubber, a few low-grade products using foam rubber, silicone rubber high temperature resistance, corrosion resistance, good sealing, long service life, foam rubber sealing is poor, easy to fall off, short service life.

A brief analysis of the future prospects of vacuum packaging technology.

Vacuum packed products have been widely used in people’s life. Vacuum packed products have many advantages, such as preservation of quality and freshness, anti-corrosion and rust, small space occupation, easy to carry, etc. Vacuum packaging is widely used and has penetrated into all walks of life, and is welcomed by everyone!