Fillers
Flexible pvc compounds have excellent impact resistance. However, when the end use application will be used under extreme outdoor conditions, fillers are added to perfect surface gloss, mechanical profile properties, color, weathering properties, etc. Filler types include carbon black, aluminum hydroxide, talcum and calcium carbonate.
UV Stabilizers
UV stabilizers slow or stop the degradation process by reacting with radicals. The formulation of the stabilizer is specifically designed upon data about geographic location, weathering conditions, application type and expected life time. A well balanced incorporation into the compound is essential because the stabilizers can impair the flame resistant properties of a product.
UV Light Absorbents
Absorbents convert UV radiation into thermal energy which then disperses throughout the material. The performance of light absorbents alone is generally not sufficient for applications with extreme weathering conditions. Common types of UV light absorbents include:
- Carbon black is one of the most efficient and cost effective light absorbents and is a standard additive to grey and black formulations. Hence black compounds already offer good resistance against UV radiation in moderate climate zones. On the other hand, carbon black is not suitable for intense weather exposures or in cases when colors other than black are required.
- Titanium dioxide (TiO2 ) is a widely accepted light absorbent especially for PVC products and offers very good protection against UV radiation. It is mainly used for conduit systems in other colors than black.
