When PVC profiles are recycled, they will basically turn yellow. Some manufacturers will choose to use titanium dioxide for whitening, but after adding a large amount of titanium dioxide, they cannot be made into pure white. And because of too much added, the quality of the plastic has also declined.
Optical brightener is an optical reaction additive, so adding optical brighteners to different plastic products will not change the properties of the product itself. Optical brighteners absorb light in the UV and re-emit light in the blue region. By absorbing the UV radiation they also delay the aging of plastics.
Oribrite OB-1 has good instantaneous whiteness, high fluorescence intensity, wide application range, and is also the most cost-effective optical brightener.
