Three of the detailed glaze printing technology

Third, ceramic decal paper printing technology progress

Since the fifties, the ceramic decal paper printing technology has made remarkable progress, mainly in the following aspects:

1. From hand-dial drawing to photo-engraving. Before definitive printing in the 1950s, decals were mainly printed with lithographs. Drawings were made directly on the lithographs. After the fifties, with the lithographs replacing the lithographs, the plate making method gradually shifted from the manual point. Paint progress to photomaking.

2. Development from hand-made paper to mechanical coating Early decal paper printing is the manual printing of a thin layer of paper on a thick paper substrate. Since the 1970s, it has been improved to mechanically coat polyvinyl alcohol on thick paper substrates. Butyral film as a substrate. The mechanical coating of the film not only saves paper, improves the production efficiency, but also improves the working conditions of workers.

3. From the development of hand-rolled powder to the period of early ink-printing decals on machine-rolled ink, adopt the method of printing water first and manually picking up the pigment powder. In doing so, not only the production efficiency is low, but also the health of workers is impeded, and it is difficult to produce a good superimposed effect. After the lithographic printing replaced the lithographs, in particular, the method of printing the ink with the ceramic printing machine using the printing resin binder material and the direct printing using the plain printing resin ceramic ink completely eliminated the backward processing of the hand powder.

4. From the color to the dot Because of the special color of ceramic pigments, the picture on ceramics has been colorful and colorful for a long time. However, fine observations are the mosaic of color blocks and lack of changes in shades of color. With the popularization of photographic networking technology, since the 1980s, in the process of screen printing decals, screen printing has also been adopted to better express the three-dimensional feeling and texture of the screen, and the decal paper printing quality is obvious. With the increase, Chinese ceramic art has risen again.

Fourth, glass printing

When early decal paper printing was just beginning to become popular, decals were applied to the glass and baked back to make the colored glaze on the flowers stick to the glass, but the effect was not ideal. Since the glass softening temperature is much lower than the ceramic sintering temperature, when the glaze powder on the decal is far from the melting temperature, the glass body has begun to soften, and it is difficult to achieve the desired effect.

After the 1970s, with the development of screen printing technology, the method of printing color glaze directly on glass with a screen was widely used.

1. Printing ink for glass printing is printed on glass with a screen plate, and its plate making and printing are the same as ordinary screen printing. Glass printing is characterized by its ink. The glass printing ink is mainly composed of three components:

(1) Fusible glass frit. The glass frit used for making glass ink is generally composed of silica, boron trioxide, lead oxide and alumina.

(2) Glass pigments. The glass printing must be sintered at high temperature to fix the pigment on the glass. Therefore, the pigment of the ink cannot use organic pigments, and only inorganic metal oxides can be used. Once sintered at high temperatures, these metal oxides are integrated with the glass and the glass is colored. The inorganic pigments commonly used as glass inks are as follows:

Red - cadmium sulfide; yellow - lead chromate, cadmium sulfide, uranium salt;
Green - chromium oxide; blue - cobalt aluminate;
Brown—iron oxide; white—calcium oxide, kaolin, etc.
Black - a mixture of cerium oxide, manganese oxide, etc.;

The color change on the screen is endless, and in order to display various different shades of transition and different brightness of light and shade, a variety of color materials are often used properly.

The fusible glass is mixed with a glass pigment and ground into a fine powder for use as an ink, and it is also referred to as a glass glaze powder.

(3) Diversion oil. The varnish is the link material for glass ink. It is made up of terpineol and turpentine, plus an appropriate amount of alkyd resin. On the one hand, the varnish must have a certain degree of fluidity, so that the glass glaze powder can be well dispersed therein, and has good printability; on the other hand, prior to sintering, the glass glaze must be liquefied before melting. The combustion is clean and there is no adverse effect on the formation of the color glaze.

2. Glass printing screen printing method used directly on the glass color glaze ink, according to the shape of the glass substrate, choose a different screen printing machine. A round glass body such as a glass cup or a Glass Bottle adopts a method of rotating a printing body to contain a seal; for a flat glass body, a flat printing method is used. The plate making and printing techniques related to screen printing have been described in the development of the printing of the stencil sheet in the seventh section of the twenty-third chapter of this book. Therefore, this is omitted.

3. Sintering of colored glass glazes Sintered glass colored glazes are also known as roasted flowers and are generally made in a baking oven. Sintering glass glaze, the key is to control the sintering temperature. Colored glaze inks are formulated with oily solvents and alkyd resins. Burning in the furnace takes about the following stages: First stage: from room temperature to 120°C, preheating, no change in printing ink; Stages: From 120° to 250°C, light oil vaporizes and vaporizes; Stage 3: From 250° to 500°C, heavy oils and resins are burned and gasified; Stage 4: From 500° to 580°C, in color glaze The glass powder begins to melt and the surface of the substrate glass softens slightly. Stage 5: From 580° to 620°C, the glass glaze powder is melted and melted, and the pigment powder is also melted into it. At this time, the surface of the glass body is also completely softened. Glaze and glass were combined to complete the transfer and sintering of the glaze, and then slowly lowered to room temperature.