Water-based ceramic ink printing failure causes and solutions (2)

4, ceramic graphic discoloration

The discoloration of the image after burning of the waterborne ceramic screen printing ink is often due to wood science compatibility in the (color) ink system. For example, penetrants (dispersants) that react with aqueous screen printing ceramic inks and metal oxide pigments are added by mistake.

Note: The basic requirement for the coloring on the glaze is that it must be firmly attached to the glazed surface at a glaze temperature of 700-900°C. For this purpose, it is necessary to mix with an aqueous medium without allowing the coloring pigment to penetrate into the glaze due to the dispersant and flow.

5, ceramic products on the same color difference

In the firing (junction) process, the dispersion medium (such as resin and water solvent) as the linking material in the graphic will be converted into dust or gas and volatilized with the increase of the firing (junction) temperature. Colorant. However, due to differences in the number of screens, printing pressures, and the type of colorant contained in the water-based screen printing ceramic ink system, or the residual medium in the graphic and textual materials, differences in the same color after firing (knots) will appear. .

In addition to firing (junction) under the different temperature conditions affecting the same color, the use of different metal oxides for colorants in aqueous screen printing systems can also make the color difference. For example, white colorants include magnesium oxide, magnesium carbonate, aluminum oxide, calcium borate, titanium oxide, zinc oxide, arsenate, antimony oxide, metallic silver, and yttrium compounds; red colorants include basic chromium chromate and lead uranium And uranium oxide, lead uranium, barium salt Cassius Zijin, red iron oxide and iron salt, cadmium selenium red, manganese oxide, manganese and so on. When we learned that the chemical reaction in the glaze formation process is mainly dissociation and vitrification, we can learn the difference of the same color.

6, shrinkage and bursting after firing (knots)

The main reason for this failure is the ink in the ink system (the linking material or the ink adjustment: oil emulsion glutinous rice balls Jingjing: bale blister; plasticizers and other designs are not reasonable. From: Yu Ling ink and blanks The surface has strong adhesive force, if the ink design is unreasonable, it will cause the graphic to curl, shrink and burst the flower during the process of heated firing (knot).The processing method is: reasonably design the ink composition, ink and color glaze No agglomeration can occur after mixing and grinding.

After the ink is dried, its decomposition and gasification temperature is higher than the decomposition temperature of the organic polymer. Otherwise, the ink is decomposed and vaporized in the process of heating and sintering, which often leads not only to shrinkage and blooming, but also to glaze on the ceramic surface. It will also be jacked up to form raised defects.

7, plug the screen after printing

The blockage of the screen printing plate often leads to the loss of the dot. One of the reasons for the blockage is that the ink is too thick or has large particles; secondly, the ink of the ink system does not rewet so as to dry the shaanxi.

Whether the ink is dried too fast or the ink is too rough, it can cause the conjunctiva of the mesh to be blocked during the screen printing process or the blockage of the coarse colorant to print a clear ink film pattern. The usual remedy is to add a retarder.