Resistweave Cloth Coveralls

[nuke11]

I've been researching body armor, helmets, and ballistic inserts and am having a hard time with a uniform made out of this material. It is most likely from the aramid family of fabric, but when used as a uniform this is where the problems begin for the coveralls (don't like the coverall idea either).

Most, if not all types of body armor must dissipate the kinetic energy over a wide surface area with lots of padding and multiple layers of Kevlar.

How is a uniform made out of this stuff working (coverall is around an NIJ I)The current trend in testing of ballistic resistant uniforms are soft Kevlar insert pads within the uniform itself. These are NIJ Level II with at least 24 layers of Kevlar per pad.

[kato13]

I am not sure of the physics exactly, but my assumption was that the fibers were in some ways similar to a super cooled liquid (which will rapidly freeze when disrupted).

So you have a polymer which is totally flexible, but when it is sharply shocked in some way the outer layer will stiffen and the inner layer will convert (and expand) into something like Aerogel.

It is a stretch but it is the best I could come up with.

[nuke11]

I am not sure of the physics exactly, but my assumption was that the fibers were in some ways similar to a super cooled liquid (which will rapidly freeze when disrupted).

So you have a polymer which is totally flexible, but when it is sharply shocked in some way the outer layer will stiffen and the inner layer will convert (and expand) into something like Aerogel.

It is a stretch but it is the best I could come up with.

Interesting idea, very interesting.

[mmartin798]

The most likely way it works is by infusing the fibers with a shear thickening fluid, with is basically a non-newtonian fluid. This is real world work that is being used to make kevlar more resistant to knives and shivs. Work has also been done putting this gel in a vest and stopping a round of unspecified caliber at speeds up to 1400 f/s.

Non-newtonian fluids rapidly change from a flowing liquid to almost solid when stress is applied. In a resistweave material, this would serve to spread the impact over a large area assuming the fabric is something like a kevlar or other ballistic material.

[.45cultist]

I use resistweave utilities with velcro and snaps like chemsuits.

[ArmySGT.]

I use the Air Crewman uniform as my basis for MP project fatigues.

No I don't go with the coveralls unless I am playing a straight MP rules game.

Otherwise players get....... PASGT vest and Helmet..... Second chance IIIA body armor and one ballistic shield for MARS per team.

Boots have the spike and nail proof ceramic inserts.

[nuke11]

The most likely way it works is by infusing the fibers with a shear thickening fluid, with is basically a non-newtonian fluid. This is real world work that is being used to make kevlar more resistant to knives and shivs. Work has also been done putting this gel in a vest and stopping a round of unspecified caliber at speeds up to 1400 f/s.

Non-newtonian fluids rapidly change from a flowing liquid to almost solid when stress is applied. In a resistweave material, this would serve to spread the impact over a large area assuming the fabric is something like a kevlar or other ballistic material.

Would there be enough fluid within the fiber for it to thicken enough to slow and dissipate a fast moving projectile I don't know a lot about these fluids but what would the material feel like And would it need to be kept in a certain temperature range

[mmartin798]

I can't find the video which was impregnating kevlar fibers with this kind of liquid to make them much more resistant to being stabbed with a knife. But here is one that shows the gel insert for a vest that illustrates the ability to stop a bullet. If i find the one about the kevlar and knives, which is more likely what resistweave would be like, I will post it.

http://www.sciencealert.com/liquid-armour-is-now-a-thing-and-it-stops-bullets-better-than-kevlar

Here is a link to a journal article about it. One highlight from the article is that an army research study found that 4 layers of STF impregnated kevlar was as effective as 14 layer of untreated kevlar. So as far as how it moves, would not be too bad.

http://dujs.dartmouth.edu/fall-2013/liquid-body-armor

[nuke11]

I can't find the video which was impregnating kevlar fibers with this kind of liquid to make them much more resistant to being stabbed with a knife. But here is one that shows the gel insert for a vest that illustrates the ability to stop a bullet. If i find the one about the kevlar and knives, which is more likely what resistweave would be like, I will post it.

http://www.sciencealert.com/liquid-armour-is-now-a-thing-and-it-stops-bullets-better-than-kevlar

Here is a link to a journal article about it. One highlight from the article is that an army research study found that 4 layers of STF impregnated kevlar was as effective as 14 layer of untreated kevlar. So as far as how it moves, would not be too bad.

http://dujs.dartmouth.edu/fall-2013/liquid-body-armor

Ok, it seems that a 45% reduction in layers of material can be achieved when dipped in STF.

So if we take NIJ I for an AV of 6, that would be around 9 layers of Kevlar 29. If we reduce this by 45% that would be 4 layers. Now Kevlar 29 is about .61 mm thick when woven into a cloth. So that would be about 2.45 mm for 4 layers of Kevlar 29, too thick for a uniform, but we have other options to look at now.

Kevlar 159 (correctional fabric Kevlar) which is .18 mm thick when woven into a cloth and then Kevlar LT (comfort Kevlar) which is .15 mm thick when woven into a cloth http://www.kevlarsupply.com/kevlar-fabrics/

So looking at this information we could be using a combination of say 5 or 6 layers of Kevlar 159 and LT to come up with a uniform that is about 1.25 mm, which I think would be around the same as the current CORDURA NYCO fabric (need to research this more).

So I think we do have a technical solution to what Resistweave could be, but then this opens up the question of layered clothing, undershirt, shirt and jacket an AV of around 14

[ArmySGT.]

I think we need to consider wear and abuse in the resistance factor. Wearing on a daily basis and a weekly wash (if possible!) are going to significantly impact the ballistic protection of a set of coveralls.

[cosmicfish]

Just as a quick note, TMP is full of technologies for which we do not have any current explanation. Is the goal in this thread to reduce resistweave to something that current science can at least roughly explain, or is the goal to provide a characterization of the material that would allow for a more detailed usage Because the first sacrifices game effect in order to gain an explanation while the second sacrifices explanation in order to gain a game effect.

[mmartin798]

My leanings are more like Sgt's. The description of a cache often lists replacement coveralls. This means they can and do wear out in some fashion, there is a need for extra coveralls (but why call them replacements then), or the team members take them off and forget where they put them. The latter two seem less likely than the first. So, how the coveralls work give some insight as to the degree of wear to expect.

[cosmicfish]

So, how the coveralls work give some insight as to the degree of wear to expect.

I understand that, but it is still fiat. Resistweave is a fictional supermaterial that is already clearly unlike any existing material or any material on our current technological horizon. It is suitable for coveralls (and presumably similar outerwear), it provides a certain level of protection, and it is provided without any information about wearing out other than the existence of replacements (which exist for literally everything).

Rather than guessing about which cutting edge technologies might be impossibly twisted to get something that isn't quite resistweave, why not just hammer out some rules and see if they sound reasonable

For example:

Resistweave (and other personal protective gear, which would reasonably just be made of more layers of this wonder material!) loses one SP every 2 years or for every 5 points of penetrating E-Factor (meaning that SP 7 armor hit by an E-Factor weapon would see 3 points penetrate). Keeping track of initial damage, half of it can be repaired at the expense of ten minutes and one patch (standard issue) per penetrating point.

How does that look It make no suppositions on what the material actually is because anything that exists even on the horizon would seem to contradict the game effect, but it still provides a framework for game play.

[bobcat]

the reason that the resistweave uniforms need replaced isn't ballistic degradation it's CBRN contamination. remember the mission was supposed to happen 5 years after the boom which means lots of stray fallout and undispersed chemical and biological contamination all over the place. if you're going to be working with survivors and don't want to bury half of them you need to replace the uniforms frequently enough to not track contamination all over the place.

[mmartin798]

That may be part of the reason, but it certainly is not clear. 3rd edition states the coveralls are water and gas resistant while 4th edition only states water resistance. Though you are very correct that there is most likely, in either case, an activated carbon inner lining to mitigate casual contact with harmful substances when not wearing a hazard suit. That would give a reason to replace them regularly.