Methods for Improving UV Resistance of LPCs

Conventional Polyesters Good (some yellowing with time) 

Epoxies Moderate (need surface coatings for good protection) 

Vinyl Esters Moderate (more degradation due to -OH groups) 

Carbon Good, dark color gives UV screening 

However, such addition of UVAs or pigments into the bulk of the composites is not a cost effective method. A better option is to improve the surface resistance of the composites where the weathering occurs primarily. The methods used for improving surface resistance of the composites include coating, lamination and coextrusion. All of these methods entail producing a UV resistant layer on the surface of the composites. Of these, coating is the most widely used method in the wood industry [ 14]. 

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