Modern food packaging is multifunctional. Its main purpose is to create an aesthetic appearance in order to attract the attention of potential buyers. But there are other reasons to pay attention to packaging, for example, giving products such properties as convenience in transportation and extending the shelf life. The latter quality is especially important, since unsold goods are subject to destruction, which entails direct losses.
Vacuum packaging of fish is one of the most popular methods of solving all these problems. It does not require significant capital investments and large production areas, therefore it is accessible even for small enterprises.
Depending on the volume of production, either high-performance lines or semi-automatic machines are used, which have become the most massive device by which fish are packaged.
Manufacture various vacuum packing semiautomats: one-, two-chamber, floor (on castors) and desktop. The dimensions and shapes of the chambers are also different. Packaging of fish is usually done in machines with oblong stainless steel chamber, since aluminum does not tolerate the acidic environment typical for this type of product.
The principle of the arrangement of any vacuum packer is quite simple, in its design there must necessarily be a compressor evacuating the air from the chamber and a welder creating a seam on the polymer bag. In addition, a control and parameter control scheme is required during the operation of the system, including a manometer.
The product, in this case the fish, is packed in vacuum bags, which should be considered for consideration. They are made of a barrier polymer film having a multilayer structure. The requirements for packages are quite serious: they must have optical properties that allow them to visually assess the quality of the product, the specified thickness, measured in microns (for example, 60, 100, 120 or 150), and the dimensions needed by the customer enterprise, and they may be non-standard. In addition, one side is opaque so that the fish looks more beautiful. Colors are chosen based on what kind of product is packaged, for example, red varieties look great on a golden background. Packaging for fish is usually oblong, while for meat products, square packets are often used.
Welders inside the chamber can also be different, they are linear and angular. The latter are used for closing on both sides in cases where the fish is long and it is difficult to pack it in a package through its narrow side.
Vacuum packaging of fish can significantly extend the shelf life if it is produced with pre-extrusion of air from the chamber with special gas mixtures prepared for each product. The fact is that in nature there are anaerobic bacteria, to which the absence of air does not interfere with multiplying and damaging the packaged fish. The so-called "subgas", which precedes the usual packer cycle, reliably protects them from them.
The operation of vacuum packers is quite simple and does not require special qualification. It is necessary to monitor the state of the Teflon fabric, which is covered with the heating elements of the welders, and monitor the condition of the oil in the compressor through a special glass window. If its color became beige, foam is visible, so it needs to be changed.