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Decorating goods
There has been a very clear downtrend in the cost of manufactured products lately. What is the reason for that? First of all it is the toughest competition at the consumer goods market. New manufacturers enter the market offering goods with very good performance at more attractive prices. The secret of low price lies also in cheapening of production technology and used materials. In this article we are going to cover one of the ways to reduce the cost of china and glass factories production. We all know very well that the commercial success of any glassware or china item for home use depends a lot on decoration. The cost of decoration is by far trttfuiTrrcosfT" Russian gfass and china industries traditionally use paints with high baking temperature for decoration of kitchenware and consumer goods, although in some cases organic dyes would be more effective.
 Organic-borne varnishes have a number of advantages as compared to high-temperature paints: First, the lower unit cost; Second, short setting time and lower temperature required for setting - 5 minutes at 180°C instead of 1 hour at 600°C, and therefore higher economic and production efficiency of the process.
If production is just being set up, then the lower initial expenses will be of great importance: a cheap and economic drying chamber will be required instead of the expensive and "voracious" baking oven. Just compare: a medium-sized baking oven takes about 150 sq.m of useful area, while the drying chamber is less space-requiring and can be accommodated in almost any room.
Simplicity and flexibility of the entire production process is yet another undoubted advantage of production management, from the possibility of hand painting to the use of high-performance automatic oainting lines. Due to the wide range of varnish colors and tints it is possible to get a great result with any selected decoration. Using organic-borne varnishes we can get both transparent and flat colored finish of any tone and intensity, as well as a wide spectrum of non-transparent metallic finish with pearly effect.
So, we have seen that all coatings based on organic-borne varnishes feature good hardness, resistance to scratches and chemical solutions.
The process of painting on painting line includes :."e following stages and is rather simple:
- plasma treatment of the item surface before oainting to remove dirt and dust;
- varnish application by spraying in the painting chamber;
- evaporation of solvent in a special zone;
- coating setting in a tunnel oven at 200-250°C with exposure time usually not exceeding 10 min. Exposure time depends on the item weight and size: thus 5 min at 180°C is enough for complete setting of coating, but some more time is required to heat the item to the desired temperature. It is obvious that hand painting may be used for small areas with minimum equipment cost; however the efficiency of such method is only several hundred thousands of items per month. Installation of an automatic line for painting of glassware or flatting by means of painting makes it possible to significantly increase the quality and efficiency.
The painting capacity of one line is from several hundred thousands to several millions of items per month. Electrostatic spraying at the stage of varnish application allows to reduce the cost by up to 50% and to After organic-borne varnish has hardened in the oven we get a very strong coating enduring hundreds of cycles in a dishwashing machine.
The use of paints makes the whole painting process economically efficient. For example, the cost of materials for painting a small scent bottle into a bright color is as small as 0.3-0.5 rubles, and for flatting of a bottle - about 1 ruble. Due to combining painting and setting at one line all production process takes as few as 15 min, and production capacity depending on the type of painting line and size of item may reach the value of 120 items per minute.
The use of flat varnishes in painting of glassware allows in many cases successfully replacing such traditional flatting techniques as chemical etching and abrasive treatment of glass, which are hazardous for both human health and environment.
In recent years the leading manufacturers have developed and recommend transparent, flat and painted varnishes on epoxy or polyurethane base for painting. These new materials do not require any special adhesive dressing and have become wider known due to the simplicity of their use.
Unusual possibilities for serial decoration of glassware and ceramic items are provided by the 3D image transfer method. The core of this method is the transfer of selected design from a special water-soluble film onto the item being decorated. The film is put into a water bath with adjustable temperature.
After the base has dissolved and the thin dissolvable fiim with an image has uniformly spread upon the water surface, the item is placed into the bath and the image transfers onto the item surface. Before this the item should be coated with primer, enamel or varnish. The use of colored sublayer of primer or enamel significantly expands decoration capabilities. To secure the image the surface is lacquered and exposed to a short thermal treatment (5 min, 180°C), during which the paints migrate into the finish and get tightly secured in it. It should be noted that the item being decorated can be of any shape, which is of course very convenient for the manufacturer enabling him to perfect the products design.
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