1、Titanium Dioxide Particle Size and Particle Size Distribution

The particle size requirements for titanium dioxide used in plastic profiles are much finer compared to other fields. Typically, industries such as coatings require a particle size range of 0.2-0.4 micrometers, while for titanium dioxide used in plastic profiles, the particle size requirement is 0.15-0.3 micrometers. This allows for the attainment of a blue undertone, as within the blue undertone, visually and based on the principles of colorimetry, the perception tends to be whiter. From the perspective of plastic profile processing, this helps to mask the light yellow color of resin raw materials and the yellow color of other materials. However, making the particle size too fine is not necessarily better; if the particle size is too fine, it can significantly reduce the weather resistance of titanium dioxide, affecting its performance. At the same time, it is desirable for the particle distribution range to be as narrow as possible, with virtually no presence of abnormal large particles. Titanium dioxide particles within the optimal size range can effectively scatter incident light in the visible spectrum.

2、Coverage of Titanium Dioxide

The coverage of titanium dioxide in the profile industry is expressed in terms of opacity. The higher the opacity of titanium dioxide, the higher the whiteness of the plastic profile after coloring. The coverage of titanium dioxide is mainly influenced by the particle size distribution, particle size, and crystalline form of the pigment.

3、Dispersion of Titanium Dioxide

The dispersion of titanium dioxide has a significant impact on the production of plastic profiles, and it is an important performance indicator in the plastic profile industry. Titanium dioxide with good dispersion results in a uniform appearance of the profile, without yellowing and with high whiteness. The main factors affecting the dispersion of titanium dioxide include particle size distribution, specific surface area, surface potential, pH value, etc.

Qualitative characterization of titanium dioxide dispersion is done using electron microscopy, while quantitative methods generally involve particle size distribution measurement using a particle size analyzer. Currently, most research and production units evaluate dispersion effectiveness through practical tests to determine the quality of dispersion.

4、Optical Properties of Titanium Dioxide

For plastic profiles made from various substrates, the main optical performance indicators are the brightness and hue of titanium dioxide, with the test results obtained from instrumental measurements being the primary source for these two indicators.