How to select titanium dioxide for PVC sys.?
Key points and precautions for selecting titanium dioxide for PVC profiles:
1, Excellent long-term weather resistance.
In order to adapt the PVC profile to the requirements of the door and window, the PVC profile must have excellent weather resistance. In addition to adding antioxidants and UV absorbers to the PVC system, the weather-resistant rutile titanium dioxide is the most efficient way to the white PVC profile against UV damage. Titanium dioxide is a white pigment in PVC profile systems and an important light-shielding agent. When a sufficient amount of TiO2 is added to the PVC furnish, most of the light irradiated on the surface of the profile is reflected, thereby protecting the PVC molecular structure from damage, but the titanium dioxide itself has a photocatalytic effect, which leads to the gradual degradation of the polymer. Degradation begins with a decrease in surface gloss and gradual pulverization as the pigment is exposed to the light one layer and another. In order to reduce the photochemical activity of titanium dioxide, a method of coating with a metal oxide such as Al2O3, SiO2 or the like coating method in the process of producing titanium dioxide. When titanium dioxide is used, the time coast of pulverization can be used as a quality measure of titanium dioxide stability.
2. Flow Dispersibility.
Since the PVC-U system for doors and windows is a non-plasticized non-wetting material system, the titanium dioxide used for PVC-U profiles should have better dispersibility and dry powder flow.
3. Select the suitable titanium dioxide for the PVC-U profile of different stabilizer systems.
When using lead salt stabilizers for PVC profiles, such as titanium dioxide without surface treatment, under the action of sunlight and water, PVC profiles will produce gray color, which will affect the appearance and color of the products. Therefore, when using lead salt stabilizers, Choose a surface-treated titanium dioxide variety, such as the special developed TINOX® R-2280 & TINOX® R-2240.