Characteristics of Titanium Dioxide for the Papermaking
Papermaking is the third largest user of titanium dioxide. Titanium dioxide is not generally used in low-grade paper due to production costs. Porcelain clay, talc and calcium carbonate are mainly used, but they reduce the strength and increase the weight of the paper. Titanium dioxide must be used in decorative paper, Bible paper and paper money (e.g. dictionaries, pictorials, magazine covers, computers, banknotes, photocopier paper and decorative paper). Paper using titanium dioxide has good whiteness, high strength, glossy, thin and smooth, does not penetrate when printed, and is 10 times more opaque than calcium carbonate and talc under the same conditions, and can also reduce its weight by 15% to 30%.
Decorative paper, also known as titanium white paper, is mainly used as a raw material for making furniture, flooring, wallpaper, etc. For papers with ageing resistance requirements, rutile must be used; more rutile is used in high ash papers, and this high ash paper must use rutile because the covering power of anatase titanium white does not meet the requirements. Rutile is used in low grey paper, such as Bible paper and banknotes. Bible paper requires good opacity, which is generally met by using anatase; mint paper also requires good opacity, which is mainly used in anatase. In China, the amount of titanium white used in decorative paper is much higher than the other two varieties, and this situation is determined by the level of consumption in China. Due to the large demand for house decoration and high-grade furniture, the amount of decorative paper gradually rose; Bible paper due to the use of titanium white as raw materials, the cost is much higher than ordinary paper, given the level of domestic consumption, the market for Bible paper is very limited; and the manufacture of mint paper is controlled by the state, the amount of relatively stable, will not have an impact on the titanium white market. According to incomplete estimates, the domestic use of titanium dioxide for decorative paper is more than 30,000 tons per year. Decorative paper in the amount of titanium white 20 ~ 40%, other paper in the titanium white 1 ~ 5%. As the traditional cultural paper production plants have been transformed into the production of decorative paper, decorative paper production increased rapidly, the price of decorative paper in recent years is a downward trend.
Regardless of which paper (original paper), the production process is the same:
Rutile for weathering, high ash paper, anatase for weathering requirements are not high, low ash paper, the main reason for deciding what titanium white paper mills choose is the cost of paper, that is, the cost performance of titanium white. As the proportion of titanium white in the cost of paper up to 30 to 50%, so paper mills in the case of meeting the requirements of users, the choice of titanium white can be said to be calculating, can use anatase never use rutile. Paper industry requirements for the quality of titanium white, in the order of importance for:
1) Opacity (opacity): the ability of paper containing the same titanium white to cover the base colour, this indicator determines the cost effectiveness of the titanium white. Simply put, a titanium white with high opacity is generally more expensive but uses less, so the cost of titanium white per tonne of paper may be lower; a titanium white with low opacity is less expensive but uses more, resulting in a higher cost per tonne of paper.
2) Whiteness: the whiteness of the titanium white determines the appearance of the paper after forming
