Ballistic Protection / Body Armor / Go into your Kitchen

[7SFCW4]

Good Morning, One of the best kept secrets about ballistic protection is HDPE. High Density Poly-Ethelene. You probably have some of this "...body armor..." at home and don't even realize it. Go into your kitchen and look for a white plastic cutting board. A 3/4 inch thick piece of HDPE will stop a 230 grain .45 ACP dead in it's tracks, is will only penetrate about 3/4 of the way thru.

I can just hear the hoots now, "...what a moron...".

If you purchase two sheets of 3/4 inch HDPE and Gorilla Glue a 1/4 inch sheet of Aluminum between them, you will be surprised, should you fire thru this with a chronograph on the far end. Your average .223 or .308 rifle round may get thru, but it is far from lethal.

HDPE is not light, but, it's lighter than a sheet of Boron-Carbide level 4A plate. And you can heat it in the over and mold it to fit about any contour.

Body armor is line NODS/NVG, it can be a game changer. Don't scrimp. The folks at "BulletProofMe" can assist you over the phone, and more often that not, over the phone will discuss military over runs in stock at substantial savings.

But if you are looking for a low cost, low weight, engine block saver. Look no further.

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[U201491]

Good Morning, One of the best kept secrets about ballistic protection is HDPE. High Density Poly-Ethelene. You probably have some of this "...body armor..." at home and don't even realize it. Go into your kitchen and look for a white plastic cutting board. A 3/4 inch thick piece of HDPE will stop a 230 grain .45 ACP dead in it's tracks, is will only penetrate about 3/4 of the way thru.

I can just hear the hoots now, "...what a moron...".

If you purchase two sheets of 3/4 inch HDPE and Gorilla Glue a 1/4 inch sheet of Aluminum between them, you will be surprised, should you fire thru this with a chronograph on the far end. Your average .223 or .308 rifle round may get thru, but it is far from lethal.

HDPE is not light, but, it's lighter than a sheet of Boron-Carbide level 4A plate. And you can heat it in the over and mold it to fit about any contour.

Body armor is line NODS/NVG, it can be a game changer. Don't scrimp. The folks at "BulletProofMe" can assist you over the phone, and more often that not, over the phone will discuss military over runs in stock at substantial savings.

But if you are looking for a low cost, low weight, engine block saver. Look no further.

Other names are Marine Plywood,
Starboard, UHMW,

and another item is any polycarbonate sheeting of proper thickness.
1" can stop a 30 cal round.

 

[Riot]

HDPE cutting boards vs .40 S&W - YouTube

 

[Sabertooth]

Or you could borrow that plastic peace of material on the bottom of your neighbors drift boat.

 

[AMProducts]

I've been reading about experiments with UHMWPE (ultra-high molecular weight poly ethylene) a decidedly different species than HDPE (high density poly ethylene). However I have yet to try any experiments, that said, there is a decided difference between HDPE and UHMWPE. The most important part, is that what makes a material UHMW is the cross linking between the polyethylene chains. It also seems that the UHMWPE is acting as a semi-rigid substrate for a spectra fabric, this is far from being a cutting board.

In the theme of "extraordinary claims require extraordinary evidence"... lets see it, because right now you're looking to be in the "moron" (your words) camp.

 

[Jamie6.5]

Good luck trying to glue HDPE to anything, even itself. Plastic welding works when attaching it to itself though. This is true of all polyethylenes, which are members of the polyolefin family.

3M has been working on a glue/cement for it for years, with marginal results, and it is expensive.
Super glue will not work, if the joint is stressed at all, it will just pop apart.
If you want to laminate it to something like aluminum sheet, mechanical fasteners like screws or rivets would be an option.

When dealing with PE tarps (the blue plastic ones) one of the best ways is still good ol' duct tape on a clean section. But nothing permanent has been developed yet.

 

[1337BaldEagle]

HDPE cutting boards vs .40 S&W - YouTube

I think 7SFCW4 is trying to kill me

 

[Riot]

Good luck trying to glue HDPE to anything, even itself. Plastic welding works when attaching it to itself though. This is true of all polyethylenes, which are members of the polyolefin family.

3M has been working on a glue/cement for it for years, with marginal results, and it is expensive.
Super glue will not work, if the joint is stressed at all, it will just pop apart.
If you want to laminate it to something like aluminum sheet, mechanical fasteners like screws or rivets would be an option.

When dealing with PE tarps (the blue plastic ones) one of the best ways is still good ol' duct tape on a clean section. But nothing permanent has been developed yet.

I've had good results with Gorilla Glue

 

[cookie]

Good Morning, One of the best kept secrets about ballistic protection is HDPE. High Density Poly-Ethelene. You probably have some of this "...body armor..." at home and don't even realize it. Go into your kitchen and look for a white plastic cutting board. A 3/4 inch thick piece of HDPE will stop a 230 grain .45 ACP dead in it's tracks, is will only penetrate about 3/4 of the way thru.

I can just hear the hoots now, "...what a moron...".

If you purchase two sheets of 3/4 inch HDPE and Gorilla Glue a 1/4 inch sheet of Aluminum between them, you will be surprised, should you fire thru this with a chronograph on the far end. Your average .223 or .308 rifle round may get thru, but it is far from lethal.

HDPE is not light, but, it's lighter than a sheet of Boron-Carbide level 4A plate. And you can heat it in the over and mold it to fit about any contour.

Body armor is line NODS/NVG, it can be a game changer. Don't scrimp. The folks at "BulletProofMe" can assist you over the phone, and more often that not, over the phone will discuss military over runs in stock at substantial savings.

But if you are looking for a low cost, low weight, engine block saver. Look no further.

I wouldn't stand behind the cutting boards and feel protected.

 

[Jamie6.5]

I've had good results with Gorilla Glue

That's great Riot!
From the GG website:
Gorilla Glue - Gorilla Glue Guide

**Bonds most plastics, but not polyethylene or Polypropylene.

 

[mjbskwim]

Or you could borrow that plastic peace of material on the bottom of your neighbors drift boat.

And you better hurry and get it on cause you'll need it when he catches you

 

[erudne]

You expect me to give-up fried spuds for a bullet proof vest?
Ye be a mad man, a Mad Man!!!!!

 

[chemist]

Two things make UHMWPE a ballistic material, and HDPE cutting boards fail:
1) Extremely long polymer chains, which are linear, not cross-linked, and
2) Alignment of those chains, stretching them out to their full length in the fiber direction.

It's way too high tech to make PE armor yourself, but you can at least demonstrate the principle-
Take one of those thin, crispy, plastic bags and carefully pull a flat, smooth section of it until it yields. It stretches a certain distance and then becomes much stronger and less elastic. At the same time its transparency changes. Both effects are due to strain-alignment crystallization as you convert the amorphous (or biaxial, anyway) linear polymer to a uniaxially aligned, lamellar form.

If you started with UHMWPE (which is hard to make), and could do that strain-alignment stretching perfectly, you could create your own Spectra fiber, and lay it up into armor. In other words, there's a very good reason why it's expensive, and they've done a darn good job of getting the cost down, in fact. As a polymer chemist, I consider it nothing short of a miracle.

One other thing about soft armor: the way it's laminated affects its performance, just like in all composites, whether rigid or flexible. If the matrix is too hard, the fibers will snap off under load. Too soft, and the fibers pull completely out. An ideal marriage of a fiber in a matrix allows some pullout before failure, which spreads the load, arrests fractures, and imparts fatigue resistance. There's a lot to this stuff, in both the materials and the engineering.

Personally, I think six hundred bucks for a thin, light, durable garment that will stop a pistol threat is a freakin' BARGAIN.

 

[mjbskwim]

Two things make UHMWPE a ballistic material, and HDPE cutting boards fail:
1) Extremely long polymer chains, which are linear, not cross-linked, and
2) Alignment of those chains, stretching them out to their full length in the fiber direction.

It's way too high tech to make PE armor yourself, but you can at least demonstrate the principle-
Take one of those thin, crispy, plastic bags and carefully pull a flat, smooth section of it until it yields. It stretches a certain distance and then becomes much stronger and less elastic. At the same time its transparency changes. Both effects are due to strain-alignment crystallization as you convert the amorphous (or biaxial, anyway) linear polymer to a uniaxially aligned, lamellar form.

If you started with UHMWPE (which is hard to make), and could do that strain-alignment stretching perfectly, you could create your own Spectra fiber, and lay it up into armor. In other words, there's a very good reason why it's expensive, and they've done a darn good job of getting the cost down, in fact. As a polymer chemist, I consider it nothing short of a miracle.

One other thing about soft armor: the way it's laminated affects its performance, just like in all composites, whether rigid or flexible. If the matrix is too hard, the fibers will snap off under load. Too soft, and the fibers pull completely out. An ideal marriage of a fiber in a matrix allows some pullout before failure, which spreads the load, arrests fractures, and imparts fatigue resistance. There's a lot to this stuff, in both the materials and the engineering.

Personally, I think six hundred bucks for a thin, light, durable garment that will stop a pistol threat is a freakin' BARGAIN.

I been tryin' to tell folks this for years

 

[Stomper]

Kevlar....

 

[JustShoot]

Kevlar....

-
I been sewing fibers for many years and Aramid Fiber ( Kevlar/Nomex etc. ) and your discussion of UHMWPE are, ( I Think ) my friends are a close genetic kin of each other .
-

 

[erudne]

AR 500

 

[Stomper]

AR don't float! ;-)

 

[7SFCW4]

Wow! I L O V E a good rant!

Don't get me wrong. Me and Mine, we have Promax Military OTV body armor. For the vehicles, yes, I do have some HDPE where it counts. I have no illusions that I have the medical skills to fix ballistic wounds of which I have experienced too many in the past. But, should one fine ones self in some James Bond'esque situation without ones body armor, your inner McGuyver may need some Matrix like data to pull from. Around the normal home, other than linear feet of paper, HDPE is handy and available. As the wise man once said, "...improvise, adapt, overcome...", and most of all, live to fight another day.

 

[Mark W.]

I'll stick with a sheet of .200" thick 4AL 6V Titanium. I watched a .060" piece of it stop a factory 124gr 9mm round from less then 2 yards. It made a heck of a dent in the metal and a tiny bit of copper or lead might have gotten through but less then a #8 bird shot pellet.