At present, the surface decoration of ceramic ware has been changed from traditional hand-painted and spray-painted to simple and easy-to-print screen-print decals. However, the screen printing technology of ceramic decals is not exactly equivalent to ordinary screen printing. This article describes the technical issues in this area. >> Screen Printing Ceramics Beautiful Art Hall

Screen printing ceramic decals features

1) Ceramic decals are mainly used for the patterning and color decoration of ceramic vessels and can replace the hand-painted and spray-painted processes that were used in the past.

2) Screen printing ceramic decal paper resolution of up to 40 ~ 50 lines / cm.

3) After the screen printing ink pattern on the ceramic decal paper is affixed to the ceramic ware, it must be fired at a temperature of 700-800° C. or 1100- 1350° C. to adhere firmly, and the color may depend on the type of the coloring agent in the ceramic.

4) Ceramic decals are the carriers of ceramic decorative patterns and are divided into ceramic glaze decals and ceramic underglaze decals. Flower paper is slightly different due to its different composition.

5) Due to the strong hiding power and poor transparency of ceramic inks, it is currently not possible to apply the principle of three-primary coloration. Dot printing uses non-overprinting side-by-side special color ink dot printing.

6) The ink used for printing on glaze decals is high-temperature solvent type ink, and the under-glaze decal paper printing ink is high-temperature water-based ink.

Classification of ceramic decal paper screen printing

According to the order of the decals and glazing and the different sintering methods, the ceramic decal screen printing technology is divided into ceramic glaze paper and ceramic glaze paper.

1. Ceramic Glaze Applique Paper Screen Printing
The ceramic glazed applique is a ceramic vessel glazed, post-applique paper, and then sintered, ie the pattern is printed on the PVB (polyvinyl butyral) film surface with a pottery pigment web, and the PVB film is coated with the vinyl chloride adhesive. The backing paper of the agent (180 g/m2) was coated twice with a PVB solution (total thickness: 0.01 to 0.011 mm). When used, the bottom paper is separated from the screen-printed PVB film, and then the PVB film is immersed in alcohol and then transferred to the glaze of the ceramic vessel. After sintering at 780-830° C., the PVB film is carbonized and the color pattern is attached to the ceramic. The surface of the vessel completes the color transfer of the ceramic vessel.

2 ceramic underglaze paper screen printing
Ceramic underglazed appliques are first embossed paper on ceramic vessel embryos, then coated with a transparent enamel and sintered at high temperature into colored ceramic ware. The ceramic underglaze paper screen printing is to be printed on a floral paper. The floral paper is obtained by temporarily blending cotton paper and 180 g/m2 wood pulp paper. The binder liquid and the filler liquid are generally used. According to a certain proportion, it is necessary to use a special mixing solution. The graphic carrier is cotton paper, also called leather paper. When it is used, the paper is transferred to the ceramic embryo. After removing the liner, a layer of transparent enamel is applied to cover the entire ceramic embryo, and then the porcelain embryo is formed. Sintered below 1350°C into colored ceramicware.

Composition of porcelain ink 1. Composition of glaze-printing porcelain ink
Binder: It is composed of organic solvent that dissolves solids and dissolves the resin.

Coloring agent: Heavy metal oxides determine the hue of ceramics after firing.

Auxiliaries: increase the brightness of the color, so that the screen printing porcelain ink is burned and burned, and fusion with the ceramic glaze. Commonly used additives are generally lead glass body, low melting point boron.

2. Composition of underglazed screen printing porcelain ink
The same as the glaze printing ink, but the link material is a water-soluble material.

1) Use yellow or other dyed nylon mesh.

2) General ceramic products with 270 ~ 320 mesh / inch screen; flower surface with 220 ~ 250 mesh / inch screen, easier to produce relief effect; fine text products with 340 ~ 400 mesh / inch screen.

3) The ratio of the minimum screen line to the screen mesh number for color dot printing is: the number of screen lines: the number of screen meshes = 1:3, but the grain thickness, over-web, and no moiré of the ceramic ink must be considered. Comprehensive factors.

4) The moire phenomenon produced in the color dot printing can be eliminated or reduced by changing the number of screen meshes, the angle of the cable or the angle of the stretching net, the dot type, and the dot arrangement.

5) screen printing glaze porcelain ink screen should be solvent-resistant screen, with oily photosensitive plastic, water and oil sensitive emulsion or photosensitive capillary film plate.

Screen printing underglazed porcelain ink screen should be water resistant screen, with water-resistant photosensitive plastic or water-oil two sexy light plastic plate.

6) Precautions for screen printing ceramic decals
1 screen printing environment temperature is maintained at 22 ~ 26 °C, relative humidity of 65% ~ 70% is appropriate.

2 screen printing underglazed decal decals, the paper should be placed in advance printing screen, storage time depends on the ambient temperature and humidity, usually a few days, to be stable after the size of printing.

Reprinted from: "Printing Technology"