UV-skydds yta i strålkastare sanning/myt?

[HildingS]

Fick höra att när man polerar upp en plast strålkastare så slipar man även bort ett UV-skyddslager. Och ifall man inte då sätter på ett nytt lager UV-skydd därefter så kommer de att ganska snabbt gulna igen.

Så jag tänkte att jag ska googla runt lite angående detta, men man hittar förvånansvärt lite fakta om detta, mest lösa åsikter här o där.

här är t.ex en produkt som lovar ge UV-skydd: http://www.bilrutan.com/se/str%C3%A5lka ... it-5716309
Men de känner vi ju alla till att de finns många produkter som lovar guld o gröna skogar, men utan resultat eller begränsat resultat.

Det intressantaste uttalandet jag hittat på nätet är detta:

..I'm an optometrist and very familiar with UV coatings.

Most headlight covers these days are made out of polycarbonate. Polycarbonate is cheap and extremely breakage resistant. This is why it's used. But in its raw state, it is very soft (that's why it pits easily) and is very susceptible to UV damage (yellowing and oxidation). It is also the most popular material to make eyeglass lenses out of because of it's impact resistance and light weight and thinness. But it couldn't become a usable material for glasses until the manufactures (PPG being one of them, I'm sure you guys have heard of them) started putting UV resistant chemicals into the material itself (it's not a coating).

Poly is very difficult to coat with anything. It was years before our industry could develop equipment, chemicals and techniques to coat a poly lens with anything (tint, scratch resistance or AR coats). Headlight and car manufactures don't want to spend the money to use poly with UV protection mixed in cause it costs more. A few coat them with an abrasion resistant coating, but not many.

In the industry, we use UV liquid "dye" (its clear) that can cover any material. It's real simple, inexpensive stuff. But it's not a coating at all. It's heated to about 200 degrees. That way it absorbs into the lens material slightly. It offers 100% UV protection.

While this stuff is real cheap and extremely effective, there is nothing else available that can do the same thing without heating so the material absorbs the stuff. I would be extremely suspect of any company that claims it can, even at $200 a bottle. I'd be happy to test the stuff for anyone though...if you want, you can send me a small sample of headlight material, coated with the $200 a bottle stuff, and I'll put it under the spectrophotometer at work and see if it really does block UV. Then, I'll wash it a few times, etc, and see if it still does. Needs to be bigger than a quarter, but no bigger that a credit card or so.

This is also why, as far as I know, no paint manufacturer has developed paint that includes UV protection, or a clear coat with UV protection. I suppose you could develop a clear coat with UV (or even a wax), but the cost for 100% protection would be far too high. I have tested a couple of waxes that claim UV protection, and they don't.

So, in summary, I doubt there is anything available that you ask for (although I'm sure some manufacturers will try to sell you stuff).

I'd love to test anything....

http://www.tintdude.com/forum/index.php ... rotection/

Någon som har mera information om detta?

[Keawon]

Tjo. När jag själv våtslipar strålkastare eller annan plast så avslutar jag med Mequiar´s Headlight Protectant för att ge extra skydd mot just uv-ljus.

[HildingS]

hmm skadar väl knappast att sätta på :p

Men en sak jag kom att tänka på är att både halogen o xenon lampor avger ju oxå UV-ljus så då hjälper de ju inte med bara en yta på utsidan.
O en annan sak att är det en sån yta på utsidan som så lätt slipas bort så måste den ju vara typ obefintlig efter än 10års körande med en bil.. man borde ju då sätta på nytt lager kanske en gång i året o någon sån rekommendation har jag inte hört från nån biltillverkare.