Polycarbonate and Sunlight technical question

Factual Questions
1

I am considering buying a nice top of the line Fencing mask from
Leon Paul. This is a Polycarbonate clear face type mask. here is a link.

http://www.leonpaul.com/v2000/clearhit.html

My question is of a technical nature.
Since I will want to use this mask in SCA fencing as well*
This means using it outside on a regular basis.

How fast does Polycarbonate lose strength when exposed to UV?
Some facts:

we are talking about a 3mm primary plate and a thin replaceable sheet (for scratches)
The amount of sunight it woud expect to see.
2 hours a week thru spring and summer (5 months) Plus an additional 5 hours a month.

Thanks in advance.
Osip

  • [sub]I am getting information together before I bring up the mask for approval. getting all the ducks in a row so to speak.[/sub]
2

All plastics will degrade after a certain amount of exposure to UV, depending on the plastic, additives and coatings.

Quick google.

3

I think the more important question is whether the manufacturer will guarantee safety in those circumstances. Ask them.

There are different grades of polycarbonate. Some are used in outdoor applications - car headlight covers, skylight, bulletproof windows, motorcycle windshields, etc. My guess (just a guess!) is that even if it’s not made of UV-proof polycarbonate, most of the UV is absorbed in the thin replaceable sheet and the primary plate would be safe.

4

If it’s Lexan, you’re good. They make jet fighter canopies out of that stuff. It’s nearly impervious to UV.

5

The prescription safety eyeglass program through my place of employment uses polycarbonate lenses in all the safety eyeglasses that they issue, including the Safety Perscription Sunglasses, so I would imagine that it’d stand up to reasonable ammounts of UV bombardment before degrading.

6

I have polycarbonate glasses too. OK if they are on your head, they absorb UV thus protecting your eyes, but I wouldnt leave them out in the sun for 12 months.

7

yes polycarbonate does degrade somewhat in fierce sunlight. Perspex is much better for UV resistance, though not half as tough

8

It’s not so much the strength that suffers, it’s the clarity. Polycarbonate will get a bit cloudy over time if it’s not first coated. In automotive uses, parts are sprayed with an acrylic clear-coat before being sent out into the world.

9

Thanks everyone. I do of course plan on asking the manufacturer.
I just need to know a bit more about the whole sunlight effect before asking so I do not come off as a [bugs]Maroon[/bugs]

They do mention the outter sheet is coated to resist scratches, hopefully similar to headlights as scr4 mentioned.

If visibility is effected more than strength even better, They are replaceable sheets and being used in a fencing mask I am sure degradtion of visiblity will be reasonability easy to spot.

The fact the outter sheet will absord most of the UV is also a plus since it is supposed to be replaces at leaast 4 to 6 times a year.

You all are great. If anyone else has an additional information it will be greatly appreciated.

Osip