One of the details of the color glaze printing technology

Color glaze printing includes ceramic decal paper printing, enamel printing and glass color glaze printing. Among them, the use of ceramic decals is the most important one.

First, ceramic decal paper printing

The transfer printing and ceramic making of the graphic and graphic arts have a long history in China. It was applied to life and production thousands of years ago. However, it is this century that the printing is used for the transfer of ceramic color pictures. Since the 1920s, this was the printing of ceramic decals.

In the late 1920s, Gu Derun, former head of the drawing department of the Commercial Press, who had studied in Japan studying fine arts and printing techniques, co-founded Shanghai Jinhua Applique Printing Co., Ltd., which specializes in printing decals for enamel, ceramics, glass, and hardware. Wood applique. In the 1930s, the enamel industry in Shanghai was booming, and there was a great demand for decals. This situation drove the development of the domestic decal paper printing industry. Jinhua Decal Printing Co., Ltd. is at the right time and its business is booming. However, it was not long afterwards. In 1932, the Japanese imperialists launched the “June 28th” Sino-Japanese War in Shanghai, and the Jinhua decals printing factory was destroyed in Japan’s war. In 1933, Gu Derun set up the porcelain flower department in the Kangyuan can plant. In addition to continuing to print enamel decals, he also printed ceramic decals and sold them to Jingdezhen in Jiangxi Province. Before that, because China could not produce ceramic decals, the decals needed for domestic porcelain would be sold at high prices to Japan and Germany. At that time, the decals printed at the Kangyuan Plant had a decisive advantage of being cheap and good, effectively resisting the dumping of Japanese and German goods. In 1937, the aggressive war of Japanese imperialism once again destroyed the Kangyuan can plant. Japan’s aggression not only destroyed the ceramic industry in China, but also affected the ceramic decal paper printing industry.

In the early 1950s, with the revival of the ceramic industry, the ceramic decal paper printing industry began to develop. Shanghai's decal paper printing factory moved to Jingdezhen, the capital of China. Ceramic decal paper printing plants have been successively built in some of the more famous ceramic producing areas. However, there were only three ceramic decals mills in the 1950s, and the annual output was only 100 million. In addition to supplying major domestic ceramic production bases, there was also a small amount of exports. After the 1960s, ceramic decal printing was further developed. The more important ceramic decals are: Jingdezhen in Jiangxi, Jinan in Shandong, Changsha in Hunan, Wuxi in Jiangsu, Xiamen in Fujian, Shantou in Guangdong, Hebei Handan, Tangshan, and Liaoyang in Liaoning. Since the 1980s, screen printing has been widely used for ceramic appliques.

Because of the ease of screen printing, the development of the ceramic decal printing industry has been driven even further. According to incomplete statistics, since the 1990s, there have been more than 100 ceramic decals manufacturers in China.

1. Particularity of ceramic decal paper printing

Ceramic decal paper printing is a special type of printing, said that it is special, because: 1 ceramic decal paper printing ink is different from the general printing ink. 2 The substrate used for printing ceramic decals is also different from general printing paper. 3 The principle of color printing on ceramic decal paper is different from the principle of color printing on yellow, magenta and blue.

2. Ceramic decal paper printing ink

The ceramic decal paper printing ink is composed of colored glaze powder plus linking materials and auxiliary materials. Unlike ordinary printing inks, the glaze powder here is not an organic pigment in common ink, but is composed of coloring materials and glazes. . The coloring material is mainly composed of some transition elements in the periodic table, bauxite elements, rare earth elements such as iron, cobalt, chromium, manganese, titanium, vanadium, hafnium, zirconium and other oxides; the glaze is colorless kaolin, quartz, feldspar After powders are mixed, they are ground into a powdered instant glazing powder.

The inks used for printing on ceramic decals are generally divided into two categories, printing inks and screen printing inks, in addition to individual special applications. Plain ink is oily; screen ink is water-based.

(1) Printing ink.

Prior to the fifties, lithographs were used to print decals. After the 1950s, with the popularity of plain printing, lithography was gradually replaced by plain printing. Whether it is lithographic printing or plain printing, decal paper printing is the first step in the printing of printing ink on the paper, commonly known as where the vertical water, is the color material without oily link material. Then, the linking material was not dried on the top of the glaze color powder, commonly known as lotus root powder. Why do you need to apply the powder separately from the binder? Because these metal oxide particles are coarse, high in hardness, large in specific gravity, and highly inert, the oil-based binders also have poor wetting properties. On the contrary, lithographs and lithographies must continuously wet the layout with water in the printing process. Because these glaze pigments have poor wettability with oil-based linking materials, they are easily hydrated when exposed to water. Therefore, it is not advisable to mix the glaze pigment powder in the link material in one application. Only the first printing material can be used. Glaze powder approach.

It was only in the 1970s that the use of synthetic resin binders for ceramic decal paper printing inks had changed the way in which binders and enamel powders were applied separately. The use of synthetic resins instead of vegetable oils in the refining of the link material plus color glaze powder modulation ceramic decals printing ink, printability has significantly improved in order to meet the requirements of the balance of water and ink leveling. The "Ceramic Applique Resin Ink and Applied Technology Research" developed by the Shandong Jinan Ceramic Applique Factory was awarded the second prize for scientific and technological progress in 1988 by the Ministry of Light Industry.

Although the printing material of the printing ink has been improved, the trouble of the powder can be saved. However, the ink of the flat printing ink is thin, and the color of the colored glaze is not bright and thick, and it is not satisfactory. Since the 1970s, with the promotion of screen printing technology, decal paper printing has gradually shifted from plain printing to screen printing.

(2) Screen printing ink.

Screen printing inks are mostly water-based inks. Glaze powder As mentioned before, the link material is a water-soluble rubber compound, in order to improve its printability, often add some accessories such as glycerin.

3. Color characteristics of ceramic printing

Most of ceramics are handicrafts, floral fish and insects on them, blue water and blue sky, and red and green leaves. However, the principle of coloration of ceramic colored glazes is totally different from the principle of color printing of yellow, magenta, and blue three-color overprinting of ordinary color printing.

In ordinary color printing, yellow, magenta, and blue primary colors plus a black ink are used. These tricolor pigments have been developed over a long period of time, with the spectral characteristics required by the three primary colors. Yellow and magenta can overprint bright red, yellow and blue can be stacked beautiful green. However, any metal oxide in the ceramic glaze pigment does not have the spectral characteristics of the three primary colors of the pigment, so it is impossible to find three basic pigments in the ceramic glaze pigment, and it is superimposed brightly like the ordinary printing. Bright colors come. The iron color material is warm red after being roasted; the golden material is reddish purple after being baked, and they are not overprinted with yellow magenta. Similarly, copper and chromium are green after being roasted, and such green is not overprinted by yellow and green.

Due to the particularity of the ceramic color glaze coloring, the ceramic decal paper is printed with a special-color, special-purpose, multi-colored block splicing method rather than a color material superimposition method. A colorful picture requires the use of five-color, six-color, or even ten-color overlays. For example, a red flower, in order to express different shades of the petals, uses three different glaze color materials instead of red and black.

The colorants commonly used for printing on ceramic decals are gold red, manganese red and iron red, titanium yellow, chromium green, cobalt blue, vanadium black and zirconium white. Some of these metal oxides are contained in natural minerals, and more are artificially synthesized. The color change of natural scenes is endless, and these three hues alone cannot show the true color of the picture. Therefore, in practice, it is more common to mix several different colors with each other to show the varied shades of light and shade. Before the 1950s, most of them could only be deployed in dozens of shades. After decades of efforts, especially with the emergence of more synthetic colors, one or two hundred shades have been deployed.

4. Ceramic decal printed substrates

People say that ceramic decals print, indicating that the original substrate is paper. Because a large number of printing practices over thousands of years have proved that paper is indeed a cheap, suitable substrate. However, ceramic decals are not only subjected to printing ink from printing plates, but more importantly, they must also be reposted on the porcelain plates. After high-temperature roasting in the kiln, the pigments in the ink are converted into color glazes. The substrate-paper, to be completely burned into gas escapes, leaving no ash, does not affect the color effect of the color glaze. So decals are just a transit medium that takes ink and then transfers the ink to the porcelain blank.

The early gravure decals were made of tissue paper, and the latter was printed on thick paper-based tissue paper. A layer of thin paper is laid on a thick paper with a weight of 180-200 grams square meters, and then a layer of water-soluble glue is applied on the thin paper, dried, cut, and packaged for use. After the 1980s, further improvements were made to the printing media. A layer of polyethylene film is first hot-pressed on a thick paper, and then a thin film of polyvinyl butyral is applied to the film, and the film is replaced with a film of this layer to print the image thereon. After printing, the film is removed from the thick paper, which is a ceramic decal, and the thick paper base can be used continuously. The use of polyvinyl butyral facial mask not only saves paper, lowers production costs, improves working conditions, but basically leaves no ash after baking and has good glaze quality.