This test was meant to document the environmental stress limits or lack thereof of aramid soft armor. For this test I used two 6"x6" panels made by duckdiver123, who sells these on eBay for $20 a piece. These are the same panels as the ones used in my other test of these panels. However, these particular ones included two plies of polyethylene in between the 14 ply aramid halves as well as one ply of laminated aramid on both the front and back. Those additions were removed for the sake of this test, with a caveat that will be explained later.

The results of the previous test will be used as "control" results as those panels were not exposed to any environmental hazards before testing.

The armor: The armor used in this test was two 6"x6" panels. Each panel is constructed of two 14 ply halves with 1.25" quilts using aramid thread, with one half having it's quilting set at an angle to the other half. Two plies of aramid material are used as covers, to which the label is attached.



Below is with cover layers removed. SF is for "Strike Face", just a reminder to myself.



Test 1: UV Resistance.

It is known that aramid (Kevlar by DuPont brand name) degrades when exposed to UV light. It is often stated that UV exposure will damage an armor insert to the point it may be rendered unsafe. I set out to prove this is incorrect in any real world scenario. UV light does indeed degrade aramid fibers but in an armor insert there are many plies of material. The first one or two plies of material on the side facing the sun should take the brunt of UV damage, leaving the subsequent plies unharmed.

Supporting my stance is this paragraph from DuPont's Kevlar Technical Guide:



To truly test the effect of UV light on the panel I removed the outer cover layers of aramid so the ballistically relevant plies were directly exposed to the sun with zero shielding. The panel was left outside for approximately 412 hours of daylight, assuming only 7 hours of sunlight exposure a day over the course of 58 full days plus the half days when I put the insert outside and retrieved it for the test.



Caveat: This is the caveat I mentioned before. I initially believed the polyethylene plies in between the two 14 ply halves would be difficult to remove without damaging the insert and I was confident they would have no impact on the test in terms of UV exposure. Upon opening the second panel for this test (submersion panel) I knew they would have to removed for that test and found they were merely adhered to the insert and not well enough to damage it during removal. The poly plies in this panel were removed around the 140 hour mark.

I have absolute confidence the presence of those polyethylene plies had zero impact on the test. They were between the two panel halves, so there was 14 plies of aramid on top of them on the side exposed to the sun. Present or not UV light would not have penetrated anywhere near that deep through the plies. In terms of their impact on the test I consider their temporary presence irrelevant.

As mentioned, the panel was in the sun for about 412 hours. In addition to the UV exposure this panel was also left out in pouring rain for 2 days, so it was also exposed to an extreme amount of moisture. On top of that this panel had it's aramid cover layers removed, so the ballistic material itself was directly exposed to UV and moisture. Below is an image from DuPont's Kevlar technical guide which can be used as a general reference for the expected amount of degradation in percent after exposure to however many hours of UV light. As you can see it takes an extended period of time to significantly degrade Kevlar yarns.


Test Shoot:

The panel was backed up against a sand bag filled with fine sand. It was affixed to the bag with Gorilla Tape. All tests used a Glock 17 and Ruger LCR.

Rounds used -

• One .327 Federal Magnum 100gr soft point
• One 9mm 115gr FMJ

Before the shoot: On the right is the UV exposure panel, on the left is the submersion panel which was stored in a cool room until test day. The discoloration of the material and fading of the sharpie mark can be seen clearly on the UV exposure panel. However, as seen in the next photo, the interior of the panel does not have this discoloration which is only seen at the edges past the first ply of material.







After the shoot:

Both rounds failed to penetrate and were stopped on the third ply of aramid after penetrating two plies. This mirrors the results of my "control" panel from the previous test.



Shots marked. Shot 1 is 9mm, Shot 2 is .327.



Showing the third ply of material, where the rounds stopped.



Test 2: Submersion

For this test another stripped down panel identical to the first was used. The purpose of this test was to demonstrate if a waterlogged insert would still effectively stop projectiles or if it would fail. The idea behind this is that the water acts as a lubricant which allows the fibers to move and shift easily which can result in them being pushed or pulled out of the way, defeating the friction factor that panels such as these partly depend on to stop penetration.

Rounds used -

• One .327 Federal Magnum 100gr soft point
• One 9mm 115gr FMJ

Before the shoot: This panel was kept in a plastic bag filled with water for about 88 minutes, ensuring it was completely waterlogged.



After the shoot:

First shot was taken only one or two minutes after removal of the insert from the water bag. This is after shot 1, the 9mm. It did not fully penetrate but was very close to doing so, having pulled out a path through the insert. The projectile was caught in the fibers.



This is after shot 2, the .327. This round did penetrate fully through the insert into the sand bag.



Submersion panel with shots marked:



Back side:



Results:

UV Exposure Test - The results of the UV exposure test confirmed my belief that simple UV exposure is NOT a death sentence for an aramid armor insert. As I suspected the first ply of material, the one facing the sun, took the vast majority if not all of the UV damage, protecting the inner plies. An actual armor insert would also have a cover and be used within an armor carrier, providing extra barriers against UV light. The carrier alone would be enough to prevent damage.

This test could have been improved by allowing more time for UV exposure but I felt 412 hours of direct, unprotected exposure PLUS being rained on for two days was enough to get the point across. This insert was exposed to the environment in a way no armor insert would ever be when being worn. This is a level of abuse that could only be achieved purposefully and the insert still did its job as expected. Penetration and deformation both mirrored the results of my "control" test.

Submersion test - This one was a bit of a surprise for me but I now have a better understanding of the mechanics behind waterlogged aramid inserts failing. While the 9mm round did not quite penetrate out of the insert it was very close to doing so and the injuries sustained if wearing this would have likely been akin to a stab wound with extreme blunt force damage in addition. The .327 did penetrate fully through the insert and into the sandbag. The insert failed spectacularly in this test.

Retrieved slugs:







Conclusion:

The UV exposure test confirmed that simple UV exposure to an aramid armor insert does NOT mean an insert becomes useless. The panel was directly exposed to 412 hours of sunlight plus two days of rain and still performed as expected. I do not believe that UV exposure should be seen as a serious concern for aramid armor inserts.

The submersion test however showed that allowing an aramid armor insert to become waterlogged is very bad and can result in deadly injuries if a hit is taken while wearing a waterlogged insert. Laminated aramid may not be subject to this effect, or at least may not be affected as heavily due to its non-woven nature and the fact that the fibers are literally laminated together with a covering film.

There are of course limits to this test. Small sample size, uncontrolled factors, etc. But for what it is I believe it serves as a good demonstration of the resistance and limits to such resistance of woven aramid armor inserts to environmental factors.

@bluemax_1

You expressed interest in seeing the submersion test in my first thread using these panels.

Thanks for doing these.

I've always been told wet armor doesn't work but it does when it dries.

Yeah, I wasn't sure of it myself but there it is. As I mentioned the UV test panel did get rained on and it rained enough to soak the panel, so it will be fine when allowed to dry.

Awesome data! Thanks!

This backs up what I learned 20+ years ago when I started researching armor.

UV degradation only affects the the top ply and it has to be DIRECT UV exposure.  Since the armor panels are almost always wrapped in a water resistant material and then placed into a vest/carrier, there is no way for UV rays to even reach the bare aramid.

Same goes for the water test.  This is why the aramid panels are wrapped in a water resistant material.  When the panels are allowed to dry, their protection level is back to 100%