Screen printing technology to decorate flat glass

According to the principle of screen printing, the ink is printed on the surface of the flat glass, and then the curing measures of the ink are used to make the pattern firm and durable. The process is as follows:

Stretching net â†’ sizing â†’ drying â†’ printing plate â†’ developing â†’ drying â†“
Flat glass â†’ Cutting â†’ Edge grinding â†’ Cleaning and drying â†’ Printing â†“
sintering

Glass for printing

According to user requirements, the glass can be cut in a regular shape or an irregular shape, then beveled, processed, washed, and dried for use. Special attention should be paid here that there should be no traces of water on the surface of the flat glass.

The choice of wire mesh

The screen printing plate used for flat glass printing is the same as the general screen printing plate. The glass screen printing plate uses synthetic fiber screen, stainless steel screen, and natural fiber screen. When printing general color materials, either of the above screens is acceptable. Generally, cheap synthetic fiber screens are used; when used as gold and silver decoration, stainless steel screens cannot be selected. The specifications of wire mesh are generally 270 ï½ž 300 mesh.

Selection of screen frame

At present, the more regular and less deformed mesh frame is an aluminum alloy mesh frame, and its size should be larger than the pattern. The specific size should be the outer edge of the pattern from the mesh frame should be between 70-100mm. In addition, it is important to choose the frame. The key is that the horizontal rigidity is sufficient.

Stretch the net

I chose net silk and net frame to combine the two, this is the stretch net. There are many ways to stretch the net. Manual, motorized, and pneumatic methods can be used. At present, the more advanced one that can stretch the high-quality screen is the pneumatic stretch machine. The requirements for the stretched net are uniform tension, the warp and weft of the wire mesh should be kept vertical, and the sticky mesh glue should be firm and not loose.

Choose photosensitive glue

Currently, commercially available photoresists include dichromate system, diazonium salt system, and iron salt system. The requirements for the photoresist in silk-screen printing are: good plate-making performance and easy coating. The photosensitive spectrum range is 340 ï½ž 440nm, with good developing performance, high resolution, good stability, easy storage, economical and sanitary, non-toxic and non-pollution. The requirements for the photosensitive material in printing are: the plate film formed by the photosensitive material adapts to the performance requirements of different types of inks. It has considerable resistance to printing and can withstand the scraping pressure of the squeegee for a considerable number of times; it has a good binding force with the screen and does not cause film release failures during printing; it is easy to peel and is conducive to the recycling of screen materials. The DS series of photoresist produced by Beijing Taipingqiao Printing Material Factory works well and basically meets the requirements of flat glass screen printing.

Copy

After selecting the above materials, apply the photoresist in the dark room; it needs to be uniform and then dry. Generally, it needs to be applied twice. Exposure requires exposure on a cold light source exposure machine, the exposure time should be determined according to the pattern, generally between 12-30 minutes. After exposure and development, a silk screen is produced.

There are several types of flat glass printing machines: manual, semi-automatic, and fully automatic. The manual printing machine is suitable for flat glass in small batches and small specifications. Semi-automatic and full-automatic printing machines are suitable for large-volume, large-format multi-color printing, which has the advantages of accuracy and speed. The largest semi-automatic printing machine can print 2000 Ã— 1500mm glass. Fully automatic printing machines are generally used for the printing of automobile windshields. Several foreign companies can provide such equipment.

Ink

The decorative ink for flat glass is divided into organic ink and inorganic ink. The colorants and binders of organic inks are all organic. This kind of ink decorates flat glass with good results, but the film has poor firmness and poor chemical stability. It is a short-life decoration method. Inorganic inks are composed of colorants, fluxes, and binders. The colorants are inorganic colorants such as chromium oxide and cobalt oxide. The flux is a low-melting glass, and common ones are lead oxide and borosilicate glass. The most important thing about the performance of the flux is that it is not too different from the thermal expansion coefficient of the printed glass. The composition of typical fluxes: SiO2 19182%, As2O3 2113%, MgO 0146%, PbO 62110%, CaO 0127%, K2O 1183%, B2O3 10175%, Al2O3 1163%, Na2O 1176%. The connecting agent in the inorganic ink, scraper oil, is an organic substance that is completely burned out during the sintering process, but has no effect on the decorative effect.

The composition of the scraper oil is: ethyl cellulose 3g, terpineol 100ml, turpentine 10ml, alkyd resin 5ml. The ratio of the pigment of the inorganic ink to the linking agent is 10g: 8ml, which can be obtained by stirring and grinding.

sintering

Glass is an amorphous inorganic material that softens with increasing temperature. When heated to the softening temperature of glass, the glass will deform. The glass glaze is decorated on the surface of the flat glass by silk screen, and it needs to be consolidated on the glass surface by high temperature sintering, but the sintering temperature must be lower than the softening temperature of the decorated glass to ensure that the decorative glass is not deformed. Generally, the sintering temperature of glass glaze is not higher than 520 â„ƒ, usually controlled at 480 ~ 520 â„ƒ.

There are several domestic manufacturers of low-temperature glass glazes, and the prices are relatively low. There are several companies in the world that can provide similar products, but the price is one to twenty times different from the domestic ones. The domestic consumption level has not yet reached the level of using this kind of glaze, but the glaze provided by foreign countries is indeed much better than the domestic color and level. To improve the quality of decorative glass, it is inevitable to improve the grade of glaze. Sintering equipment includes flame furnace and resistance furnace. The resistance furnace is divided into vertical hanging type and horizontal roller table type according to the hanging method of glass. The vertical hanging sintering furnace has the advantages of small sintering deformation and yield rate of more than 95%, but the equipment is complicated. Horizontal roller table adjustment is not easy, it is easy to appear large deformation, low yield, etc.In addition, it is also feasible to use horizontal tempering furnace to produce decorative glass, the grade of the product is improved, the safety is also guaranteed, and it is the ideal sintering method

Little Giant Ladder

One item of Multipurpose Ladder, the Aluminum Little Giant Ladder with more special designed strong construction . It`s also be A type Ladder . or Straight ladder , the longest meters can be reached 5 meters .

You can adjust the height of little giant ladder rung by rung . It`s pretty flexible with lock by the side of ladder . The huge flared legs with slip resistant can hold the whole part of the ladder steady .

The max loading of the little giant ladder is 150kgs . Conforms to EN131 the European standard .

More details as follows :

$738A]8RN87{{28W@`V_4NGM$