Glass Screen Printing Needs to Improve Screen Printing Technology

Glass-screen printing refers to the screen printing method using glass plates or glass containers as the main products. The use of glass has a long history in China. Even today, modern glass still plays an important role in our lives. At present, the financial crisis originating from Wall Street in the United States, such as the "tsunami," generally impacts the nerves of the world and has caused a certain impact on the economies of various countries in the world. Since 2008, the soaring of international oil prices, the appreciation of the renminbi, and the reduction of export tax rebates have had a negative impact on the export-oriented enterprises of China's screen printing industry. The outbreak of this global financial crisis has resulted in the printing of originally low profits and operational difficulties. For enterprises, it is even worse, especially for small and medium-sized packaging and printing companies. In addition, after the implementation of the new labor law, the increase in labor costs has increased the operating costs of screen printing companies, coupled with the serious delinquency of their downstream customers, resulting in tight or even broken capital chain, increasing the difficulty of screen printing companies. Therefore, screen printing companies should rationally combine the company's actual situation and product characteristics, and provide services to customers with the lowest production cost and the highest production efficiency. Under the condition of this opportunity and challenge, the application of screen printing to glass products is undoubtedly a very effective countermeasure. It can increase the market development and open up a variety of marketing channels.

Glass as a building decoration material has a flat and transparent, can block wind and rain, easy to scrub and other advantages. After the screen printing, the glass is used for indoor and outdoor decoration more popular, and it greatly meets people's life and aesthetic needs. A variety of beautiful patterns are contending for creativity and exquisite work. Glass containers have begun to develop into medical supplies and industrial products. The high quality of glass products decorated with screen printing technology will become a new growth point for glass printing.

First, the glass screen printing process According to the principle of screen printing, the ink is printed on the surface of the glass, and then the ink curing measures, the printed pattern is firm and durable. The process flow is as follows: stretch netting → sizing → drying → printing → developing → drying ↓ flat glass → cutting → edging → cleaning and drying → printing sinter

1. Suitable for printing glass According to the user's requirements, the glass can be cut into regular shapes or irregular shapes, and then it can be processed by edge grinding, cleaning, and drying. Here special attention should be paid to the surface of the glass.

2. Selection of Wire Mesh The screen printing plate used for glass printing is the same as a general screen printing plate. The glass fiber printing plate uses synthetic fiber mesh, stainless steel mesh, and natural fiber mesh. When the general color material is printed, the above screens can be used. In general, inexpensive synthetic fiber screens are selected; when used as gold and silver decorations, stainless steel screens cannot be selected. The specifications of the screen generally use 270-300 mesh.

3. The choice of the frame is currently more formal, the deformation of the network frame is aluminum alloy frame, the size should be larger than the pattern, the specific size should be the pattern of the outer edge of the frame should be between 70 ~ 100mm. In addition to the selection of the frame, its strength is very important, the key is that the rigidity in the horizontal direction is sufficient.

4. The stretch net chooses the screen and the net frame to combine the two. This is the stretch net. There are many ways to stretch the net, and manual, mobile, and pneumatic methods can be used. At present, advanced pneumatic screens that can stretch high-quality screens are pneumatic stretching machines. The requirement of the stretch net is that the tension is uniform, the net latitude and longitude are kept vertical, and the adhesive net is firm and cannot be relaxed.

5. Selection of Photosensitive Adhesives The currently marketed photopolymers are dichromate, diazonium, and iron salts. The requirements for photo-sensitive adhesives in silk screen printing are: good plate-making performance and ease of coating. Photographic range of 340 ~ 440nm, good performance, high resolution, good stability, easy storage, and economic health, non-toxic and pollution-free. The requirements for printing on photosensitive materials are: the film formed by the photosensitive material is adapted to the performance requirements of different types of ink, has a considerable resistance to printing, can withstand the scraping pressure of the squeegee a considerable number of times; the binding force with the screen is good, when printing Does not produce film failure; easy to peel, conducive to the use of screen plate material recycling.

6. After the printing plate has selected the above materials, the sensitized adhesive is coated in a dark room; uniform and uniform drying is required, and the coating is generally required to be applied twice. Shaiban requires exposure on a cold light source plate, and the exposure time is determined according to the pattern, generally between 12 and 30 minutes. After the exposure and development, a screen printing screen was prepared.

7. Printing machines for printing flat glass are available in manual, semi-automatic, fully automatic types. Manual presses are suitable for small-batch, small-format flat glass. Semi-automatic, full-automatic printers are suitable for printing large quantities of large-format, multi-color printing with the advantages of accuracy and speed. The largest semi-automatic printer can print 2000 x 1500mm size glass. Fully automatic printers are generally used for the printing of windshields in automobiles. Several companies abroad can provide such devices.

8. Ink inorganic glass screen printing with two inks, one is the inorganic pigment after grinding to reach a certain degree of fineness. Plus acrylic resin, screen printing on the glass surface, the need for high temperature (600 °C above) roast 1 ~ 2min, the ink layer and the glass surface layer melt together, excellent fastness. The heat-resistant temperature of this ink is above 600°C. However, because this screen printing process is costly and the process is more complicated, it is rarely used in the screen printing industry. The other type is inorganic glass ink with polymer compound as binder. Both amino type and epoxy type are required to be baked, which is widely used in the domestic market. The applied ink is screen-printed at 1300-1400°C for 30 minutes after screen printing. The heat resistance temperature of this ink is relatively low. However, the baking time is longer, the ink has good fastness and hardness, and the brightness is also very good, and it can resist low concentrations of electrolytes and solvents such as ethanol, acetone, benzenes, and cyclohexanone.

9. Sintered glass is an amorphous inorganic material that softens as the temperature increases, and the glass deforms when heated to the softening temperature of the glass.