New z87.1-2010 ratings may be insufficient

[EagleDriver]

I am not sure about the entire thread but specifically the Z87.1-2010+ impact rating test for mass and velocity carried over from the previous impact rating for Z87.1-2003 unchanged.

High Mass and High Velocity Impact forces to be tested remain essentially the same as the prior standard. The high mass pointed projectile is pointed and weighs 500 grams and is dropped from a height of 50 inches. The high velocity test uses a steel ball .25 inches in diameter that is fired at 150 feet per second at the lens in the test frame.

The .25 inch diameter steel ball launched at 150 FPS is about 1.09 joules of force. The 500 gram pointed object dropped from 50 inches impacts with about 6.22 joules.

Z87.1 without the "+" is not impact rated and does not have to meet either of the above tests so it does not have a 1 joule rating.

[lurkingknight]

from the info posted at http://www.elvex.com/Facts-What-chan...Z87.1-2010.htm

High Mass Impact

Frame shall be capable of resisting impact from a pointed projectile weighing 500g (17.6 oz.) dropped from a height of 127 cm (50 in.).

It says frame, not the lens itself according to the way it was written here.


If you want to take the other test:

Drop-Ball Impact

Basic impact requirement for all devices: 1 inch diameter steel ball dropped at 127 cm (50 inches)

An object dropped at sea level from 127 cm will be traveling at 5 m/s.

1 inch steel ball weighs .066953 kg

.8369 Joule





mass of steel I used for calculation was http://steelmedia.com/steel-balls-data.htm

66.953 kg per 1000 balls. 1 ball is .066953kg per ball.

=0.5*(0.066953*(5*5)

.8369 J

Still not enough.

[Cobrajr122]

Originally Posted by lurkingknight

from the info posted at http://www.elvex.com/Facts-What-chan...Z87.1-2010.htm




It says frame, not the lens itself according to the way it was written here.

This is what I read as well, but when you read the testing procedure for the high mass test it DOES test the lens.

"The alignment shall be such that when the
missile is dropped, its point is in line with the
center of either of the eyes of the headform. "

Also, all this guesstimating of weights of steal balls is not needed as the weight is defined in the tests.

Drop ball test - "A 25.4 mm (1 in.) diameter steel ball, weighing 68 g (2.4 oz)"

High velocity impact test - "a 6.35 mm (0.25in.) diameter steel ball weighing 1.06 g (0.037 oz)"

[mcguyver]

Originally Posted by Cobrajr122

This is what I read as well, but when you read the testing procedure for the high mass test it DOES test the lens.

"The alignment shall be such that when the
missile is dropped, its point is in line with the
center of either of the eyes of the headform. "

So, are we saying that the testing is done with 6.22J at the center of the lense in a direct line with the eye, instead of a glancing blow (which will result in angular conservation of energy of the BB upin deflection)?

If so, this is much ado about nothing and needless fear monging that is worse than counter-productive.

[lurkingknight]

wanting to get to the bottom of a potential issue through researching the safety standards documents and seeing clarification is fear mongering?

lol

[mcguyver]

Originally Posted by lurkingknight

wanting to get to the bottom of a potential issue through researching the safety standards documents and seeing clarification is fear mongering?

It is the internet, where the uninformed see demons due to misinformation and misunderstanding.

Still, useless, reckless fearmongering.

lol

Indeed!!!

[Ricochet]

I have to agree with Mac on this. Same issue with lasers, they're either safe rated or they aren't. Any field is allowed to have its own safety rules that must be adhered to, but your safety is your own concern, at least big picture. No one should look to buy eyewear that is only rated to take a BB impact, always exceed minimum requirements. If a lense is suspect or you're not sure of its manufacturer or rating, then don't buy it. The best eye advice, and it has been said a million times on here, is "don't cheap out with eye protection".

- Only ever buy properly rated and adequate eyewear from a reliable manufacturer. Fuckin' period.

- Most safety lenses are only rated and manufacturely backed to take one strike or scratch, then the rating is considered no good. Period.

- Ballistic or Paintball rated lenses are you best and most reasonably safe bet while participating in airsoft. Period.

- All eyewear should provide the wearer with full coverage, and the frames as well as the lenses must be appropriately rated. Period.

- If you can't afford to adequately protect your eyes, then you can't afford to airsoft. Period. Go play whiffle ball or some shit.

Why on earth would anyone wear suspect eyewear? If you are concerned about a field rating being too low, then raise it however you wish. If you aren't in control of the field yet are still concerned, buy yourself adequate eyewear and let all the other idiots go blind.

[EagleDriver]

Originally Posted by lurkingknight

from the info posted at http://www.elvex.com/Facts-What-chan...Z87.1-2010.htm

The actual ANSI standard (which they make you pay for) calls for a 1.1 lb pointed object to be dropped onto the lens for the high mass test. In fact the link you posted above says that the high velocity test did not change.

But I have to agree with Ricochet's one point the most - never re-use safety eye wear that has been damaged!

Here is a good, publicly available summary:

http://www.uvex.us/inspiringsafety/e...ctive-eyewear/

[FirestormX]

Originally Posted by mcguyver

Over-react much?

Sounds like lots of theory and math trumping real-world use.

I'll stick to real-world use, and leave the eggheads to scratch themselves bald.

Says the guy whose avatar is a bald man with an egg-sized head.

With that said, "real-world use" means very little. Building and shaping impact resistant polymers is a science, that requires theory and math.

People don't say "yeah, these building codes in Canada sound like a lot of engineering theory and math trumping the real-world use of the structures in Haiti".
Similarly, people don't say "this material in my glasses that was created by my chemists, and crafted by my engineers, is pretty strong I guess. People have been using them in 3j airsoft events for years now. I know that we didn't test it for that, but I'm still going to guarantee that they will hold up to 3j anyway".

Saying "I'm not concerned. They've held up so far, and I trust my eyes to these glasses" is one thing.
But dismissing it as though anecdotal evidence is on par with "theory and math" conveys what your actually mean quite poorly.

[ThunderCactus]

The deflection test could yield sufficient impact to state they are rated for airsoft. Given that BBs tend to break or absorb some impact upon hitting the glasses, the impact force is a bit more spread out, so it's not going to penetrate as badly as a steel ball.
There are differences in impact physics between low speed and high speed impacts, but I'm not TOO worried about that since we're still dealing with a semi-soft projectile.

Using Z87.1+ glasses in industry, I'm more worried about what it means for metalworkers where they potentially have high speed, sharp edged, metal debris impacting the glasses.

[Amoki]

Too much paranoia in this thread. I have shot a 1mm Lexan at point blank with a 400FPS (~1.5J) ICS M4. Left a mark, but that's about it. Most branded glasses (ESS, Oakley, WileyX etc) are made of at least 2.5mm Polycarb.

[Cobrajr122]

pls

Originally Posted by ThunderCactus

Shooting a pair of glasses in your basement with a 500fps gun and having them survive isn't going to win someone a 1.5 million dollar settlement again UVEX because they lost an eye

[Amoki]

Originally Posted by Cobrajr122

pls

Poor logic.

Am I a representative of UVEX? No. UVEX is the company that is making the claim that their product is a "safety/ballistic eyewear" and earning dollars off that claim.

In fact, Oakley, ESS, UVEX, WileyX etc. have their glasses benchmarked by the US Army under the MCEP and to be listed under the APEL. In order to qualify on the APEL, the glasses in fact had to be shot at with a 0.15 calibre, 5.85g pellet at 640-660 FPS at a minimum so as to considered as appropriate ballistic protection.

But have I shot a piece of 1mm polycarbonate with a 400FPS gun? Yes. What people can infer from that (and there is a lot that you can infer) is up to common sense and persona risk-reward matrix.

[ThunderCactus]

Yeah but that's not how insurance companies work when you're trying to sue someone for their glasses breaking.
What's the ballistic rating on those glasses? 1j
What muzzle energy was the airsoft gun you were shot with shooting at? 2.04j

That's what lawyers refer to as a "slam dunk"

This has nothing to do with whether or not the glasses WILL protect you, it's about what they're RATED to protect you from.

[Azathoth]

Originally Posted by ThunderCactus

Yeah but that's not how insurance companies work when you're trying to sue someone for their glasses breaking.
What's the ballistic rating on those glasses? 1j
What muzzle energy was the airsoft gun you were shot with shooting at? 2.04j

That's what lawyers refer to as a "slam dunk"

This has nothing to do with whether or not the glasses WILL protect you, it's about what they're RATED to protect you from.

^is the truth.