UV Stabilization ?
Weatherability is measured through 3 key criteria's:
1. Colour retention
2. Gloss Retention (fading/chalking)
3. Retention of mechanical properties
You can add additive such as UV to the products however this does not make the product a weatherable product it improves the colour and gloss retention only. It is also important to bear in mind it will usually reduce the mechanical performance of the product. (with plastics when you add an additive to improve a type of performance you lose performance else where)
ASA Weatherability is excellent and is truly a "weatherable" material. Mechanical properties ok but not has good initially from impact or chemical as a KYDEX or ABS material. Also if you add flame Retardance additive to this you lose virtually all impact and colour and gloss retention .
ABS Good mechanical properties due to the rubber, however once in contact with UV/chemicals product losses performance and visual properties. Once Flame resistance added you reduce the mechanical property performances slightly also.
KYDEX Very good mechanical properties and as it is inherently flame retardant do you do not lose any performance mechanical properties even if weathered as the product holds all of it performance properties with in contact with UV and chemicals, however visually the product will lose colour retention and gloss if weathered.
To make a decision on the above the customer really needs decided which criteria is more important from weatherability, performance properties i.e impact/chemical resistance, FR performance, Colour/gloss retention etc.as you can see you can not have all the requirements listed below in one product.