Moulded Kevlar

[guido666]

Ok, I'm super confused about what you're doing, now. This is what I think I'm hearing...



You made Pepakura models, which you will make a mold from, then you will cast the piece in plastic, then add fiberglass, then add Kevlar?



I think that regardless of any of the stuff talked about here so far, the simplest, yet best result ("impact resistant" and "good quality" as you put it) would be to simply cast it in a high performance impact resistant plastic, like Task 12. A good pair of impact resistant glasses can stop low caliber bullets and shotgun pellets. Quality cast armor would be simple, you could make and test it in a variety of different materials before your final decision, and the result would be superb and highly durable.



It doesn't seem like there is a lot of sound engineering behind the current plan, although it does visit almost every possible combination of construction materials and fabrication methods (and also all the risks involved with each), all in one shot.

 

[Mr Toad]

I've gotta go with Awesomeness, your answers are all over the place from "doing this for a qualification" to "mass production".

If you're just looking to line the inside of a cast helmet with CF it's a total waste of money.

 

[Tylkon]

I read through this topic and have made an assumption.



TC is actually Bruce Wayne and he is simply tired of being Batman.



(Money is no object, battle ready, only TC can make it, etc.)



Actually, if TC wants to make a suit out of Play-Doh, I would still give my support. Now if we hear about a bullet proof MC robbing banks six months from now, I'll rethink my position...



p.s. If you still have the sheets from when you cut out your pep, you could actually weigh the leftover sheets versus the weight of a single uncut sheet, and use math to formulate a likely surface area. The flaps will be figured in, but if you are estimating cost, you always want to over-estimate.

 

[GremlinLord]

There seems to be a lot of confusion going on in this thread. The opening premises was he wanted to know the surface area of a model to calculate material costs. Then we got out that he wants his armor to be "impact resistant" but it will not be used for paintball/airsoft/other unsafe uses of our non certified armors.



Now I would personally love to see some new construction methods even if they are doomed to fail cause we all learn from failures. Now my option if this is for "impact resistant" armor uses a durable plastic cast like Awesomeness said. First make your pep then finish it like you want your final product to look. Then mold and cast it in your durable plastic. This is pretty much like everyone else does it.



The other way to make a durable object is to use a concoction similar to Rondo. Instead of bondo + resin use resin jelly + resin. The down side of this is that it is heavy. However I did a MK6 helmet made out of it and I would drop it on concrete without any real worries. I use that concoction to repair some rather large holes in car rocker panels, it does hold up. Resin jelly even when cured has some flex to it.



From what you have said so far you want to make a model and harden it then from the outside add thin layers of Kevlar and resin to build it up. This is very similar to the vacuum bagging system used to make boats and could work but it is a lot of work. Ether way it seems you have a plan so go forth, take a chance, and show us all up. Pepakura used to the the redheaded step child of these forums too so who knows. Very few people on this board have ever tried the method you are talking about using so pretty much anything we say is just our opinions, including me. I'm not here to dissuade you based on cost or my own opinion as you never asked for it; all we can do is provide the info you wanted and insight where you ask for it. Again at this point all we can do is wish you luck and answer any further questions.

 

[Mr Toad]

Help and advice can be given in many ways. Sometimes the best advice is to not waste the time or money.

 

[Trigger]

Well I personally didn't say anything about him wanting it to be impact resistant or anything I don't judge I'm just saying that if all he was gonna do was glass the inside with it that would be a complete waste... What would make more sense is if he did was make casts of the armor pieces then vacuum sheets of carbon fiber and pop them off like how carbon fiber is normally made. Which it sounds like he wants to make the pieces and then fiberglass over them and then carbon fiber over that? I hope you don't mean laying strips on it again you wouldn't get the look of carbon fiber it would look like carbon fiber patchwork quilt and thats no bueno. You need to find out how to properly form carbon fiber. As to explaining the vacuum forming process with carbon fiber sorry I ain't got much of a clue. Cast, vacuum form, finished part? lol



PS most of carbon fiber's strength comes from it's high quality resin, the carbon fiber provides a strong - lightweight medium to form around, kind of like concrete and rebar.



Oh yeah, and definitely good luck

 

[Mr Toad]

Well I personally didn't say anything about him wanting it to be impact resistant or anything I don't judge I'm just saying that if all he was gonna do was glass the inside with it that would be a complete waste... What would make more sense is if he did was make casts of the armor pieces then vacuum sheets of carbon fiber and pop them off like how carbon fiber is normally made. Which it sounds like he wants to make the pieces and then fiberglass over them and then carbon fiber over that? I hope you don't mean laying strips on it again you wouldn't get the look of carbon fiber it would look like carbon fiber patchwork quilt and thats no bueno. You need to find out how to properly form carbon fiber. As to explaining the vacuum forming process with carbon fiber sorry I ain't got much of a clue. Cast, vacuum form, finished part? lol



PS most of carbon fiber's strength comes from it's high quality resin, the carbon fiber provides a strong - lightweight medium to form around, kind of like concrete and rebar.



Oh yeah, and definitely good luck

Actually the resin has little to no strength properties in a CF buildup. Its the fabric that has all the strength. Also, using the helmet like a male mold and laying up the CF overtop of it would quickly wipe out all but the largest details.

 

[009 SPA]

I'm pretty sure that I'm going to use Kevlar, not carbon fibre, since you don't have to do any fancy vacuum shenanigans. I may have mentioned this before, but since I am making this mostly at school, I do have an entire technology department helping me with this project, and they seem to have no problem with my proposals.



On a separate note, I'm glad I researched titanium before asking people on this site. As much as I would love to use it, the cost would be phenomenal. I'll have to settle for aluminium plating instead.

 

[guido666]

Now we've moved to aluminum plating? Where's the anti-troll spray?

 

[009 SPA]

Oh no, what I mean is I'm attaching aluminium plates onto the finished casts.

 

[Mr Toad]

Carbon fiber, kevlar, aramid etc it's all basically the same from a process standpoint particularly what you are looking to do. I also never said it couldn't be done, just a waste of money and time.



You have also never directly answered the question of wht and why you are wanting to do? Are you just trying to make the most expensive suit ever?

 

[Trigger]

Toad, a sheet of carbon fiber without its resin is flimsy... and resin without the carbon fiber has no strength.

 

[Mr Toad]

Toad, a sheet of carbon fiber without its resin is flimsy... and resin without the carbon fiber has no strength.

Here, read this:



http://carbonfiberhe...m/important.php



Partucularly the last sentence of the 2nd paragraph.



"Resin really has no strength in comparison to the fiber. So you need to control the resin content to a minimum versus fiber. Basically the resin is there to keep the fibers in place"



By the way, I work for Boeing on the 787 which, last I checked is a composite aircraft. I do know a "little" about what I'm talking about.

 

[Trigger]

Again, try making a helmet without the resin. The resin holds the stiff microstructures in the carbon fiber together without the resin the fiber has no strength.

 

[009 SPA]

Yeah, I'm basically doing the first process mentioned.

 

[Trigger]

I'm still confused as to what that is SPA, would you mind elaborating? Sorry this is just confusing.

 

[009 SPA]

If you like, I can spell out my project plans without trying to be patronising:

1. Construct all the parts of the suit using the normal Pepakura process, right up to priming.
   
2. Mould all of the parts using either fibreglass or a moudling plastic.
   
3. Cast all the parts by using about three steps to get the finished suits:
   
   • Brush or spray on pigmented gelcoat (outer surface of the armour)
     
   • Use fibreglass cloth or tissue to get all the details filled in, and patch up larger gaps with fibreglass cloth
     
   • Lay up the inner layer of Kevlar, using epoxy resin
     

I hope that makes things perfectly clear.

 

[guido666]

Where's the aluminum/titanium at?

 

[KevlarSpartan]

Battle Ready? What do you expect to do in this costume? Kevlar laminate is more than layering sheets in a resin. Kevlar helmets are cured under heat and pressure in a mold. Even the newest models will only stop a 9mm, and I question that.



Use whatever materials you like, that is your choice, but please do not go testing the armor against projectiles. I fear the best you would have is a cool looking costume to die in.



If you want to play paintball in the armor, there are some resins out there that are extremely tough. Only use approved protective masks though.



SSG V

Haha, yeah, tru stuff, i don't plan to be in the thing while im doing it, but i do plan to do testing, beginning with your low calibre rounds. And the Zylon resin usually takes place for curing, kind of a "no cooking required" method of bonding.

 

[Trigger]

Nah that's not being patronizing. I only wondered cause there was some speculation, so I wanted to hear it from you personally lol.