In general, if a small amount of iron, chromium, cobalt, copper mix in the titanium dioxide will lower the brightness and there will be color cast in the printing ink. Therefore, it's very important to choose fine and inclusion-free titanium dioxide. Titanium dioxide particle's shape and size have an effect on whiteness. Superior titanium dioxide particles have a smooth surface and have non-angular. If you use titanium dioxide with angular, it will weaken the reflection of light and thus reduces the whiteness. Titanium dioxide particle should have suitable size and should be evenly distributed, which show good whiteness.
The impact of titanium dioxide on the printing ink covering power: the refractive index’s level of titanium dioxide itself will directly affect the size of the printing ink covering power. When preparing for the white printing ink, you should select high refractive index titanium dioxide, which enhance the covering power of white printing ink.
Titanium dioxide tinting strength depends on scattering power of titanium dioxide to the visible light and titanium dioxide has a direct impact on the printing ink tinting strength. The bigger the scattering power coefficient, the stronger the tinting strength. Titanium dioxide is the highest refractive index product in white pigment, and the refractive index of rutile titanium dioxide is higher than anatase titanium dioxide applied in decorative paper. Therefore, you should choose the titanium dioxide which has strong scattering power and high refractive index.
The titanium dioxide particle’s shape and the light reflection have a direct impact on the dispersion properties of titanium dioxide. If the titanium dioxide particles’ surface is smooth, reflection is uniform, it has a good dispersion properties and the white ink made by it will has a good gloss and whiteness.
In summary, with the rapid development of domestic and international packaging and publishing and printing industry, the demand of printing ink will increase. As a white pigment, titanium dioxide is very important for printing ink and many of its property and function can’t be replaced by any other materials. Therefore, the number of titanium dioxide in the printing ink for walnut decorative paper will increase year by year, the market will be very broad.