Non-stick cookware has become a part of modern everyday life. However, the presence of such a coating does not yet guarantee its quality and durability - the whole point is that there are several methods of processing products.
Modern non-stick coatings are based on polytetrafluoroethylene (or PTFE) polymer. In its properties, the compound is close to noble metals; those. does not react with most aggressive media. At the same time, PTFE is not toxic. Today, there are two main methods of applying non-stick layers.
This method is characterized by a short production cycle time. The thickness of the applied layer is brought to 25 microns. Roll-up is considered an economical method; products processed in this way belong to the economy class and are available to most consumers. How does the process take place?
First, blanks are prepared in the form of aluminum discs with a thickness of up to 2, 7 mm. The production line is a mechanism up to 50 meters long. This includes coating rolls, a pre-drying oven and a finishing oven. First, the discs (3 in a row) are fed into the pre-firing and drying oven. Here the residues of technical oil remaining during the stamping of disks are burned out; along the way, the workpieces are heated to the desired temperature. Next, the first layer of non-stick coating is applied by means of rollers. Then the discs go to the pre-drying oven. Thus, up to 5 coats can be applied. Sometimes a decorative coating is applied over the latter.
According to the technology, the number of layers cannot be less than three. The first coat facilitates the application of subsequent ones; the second, the thickest, is the main one, the third reinforces the previous ones and carries out a protective function. At the end of the line, a product is obtained with a layer thickness of up to 25 microns, which is sufficient to maintain non-stick qualities during the manufacturer's declared service life (usually 1 year).
The main advantage of this method is obtaining a thicker non-stick layer (up to 60 microns), which makes it possible to increase the service life and increase the strength of the coating. Spray-treated dishes are elite, their service life is 3-4 years. How does spraying take place?
The stamped discs are fed into the tunnel, where oil residues and other contaminants are removed from them by means of special detergents; at the same time roughening (for better adhesion). After the washing procedure, the workpieces must not be touched so as not to leave traces of fat. Then the discs are installed in a rotating holder (120 rpm), and PTFE is supplied to them from the nozzles under pressure. As in the roll-up method, each layer is dried and finally warmed up. If necessary, a drawing or pattern is applied to the last layer using silk-screen printing.