Simply, the dispersion is the degree of scatter particles of pigment occurring in the medium of the base in certain condition of dispersion and time. Or under certain condition of dispersion, the needed time for the system to reach the certain degree of dispersion. During the process of producing the titanium dioxide, the semi-finished product should be grinded generally to make it have qualified fineness so that the surface treatment can be carried out. If the titanium dioxide can not be scattered fully during this process, it will accour agglomeration problem, causing the grinding difficult.

Dispersivity, also known as abrasive dispersing or abrasive wetting, is called water dispersion when used with the medium as water and is called oil dispersion when used in coating systems such as solvent. The dispersion index is an important application index for tio2 titanium dioxide. Whether the dispersion is good or not will affect not only the index like reducing power, covering power and oil absorption, but gloss and weather resistance of coating film or the shape of profile. When grinding and dispersing in paint industries, the quality of dispersivity will influence the dispersing time, which is one of the significant economic indexes in the production of paint. Also, when the grinding time is too long, it will increase the pollution of the equipment, leading to bad whiteness of the products. When manufacturing the plastic masterbatch or profile, dispersion will have an impact on periodic replacement of the screen mesh of head and the performance of final products.