Sciencemadness Discussion Board

Strapping Tape for Confinement

twelti - 24-5-2019 at 13:11

When I was a wee lad, I used to make FP bombs using handmade paper tubes and with strapping tape around it. You know the tape with fiberglass strands in it. That stuff is amazingly strong and light. I have been thinking of using it for caps, since I am not wanting to use metal tubes (yet anyways). I know there are other options (rolled aluminum foil, carbon, plastic). The nice thing about the strapping tape is you can control how much confinement for each piece, and even where the confinement is. I also don't see it ballooning, it seems like it would hold strong and then just break. I even had some ideas about strategically placing the tape to control how the cap fragments.

Has anyone here any experience or thoughts on it?

MineMan - 24-5-2019 at 16:12

Do you have a link for this tape?

twelti - 24-5-2019 at 16:36

Like:
https://www.tcdtape.com/product/heavy-duty-filament-strappin...

here is comparison of different tapes tensile strength:
https://www.youtube.com/watch?v=uIgls3LM2CE

[Edited on 25-5-2019 by twelti]

SWIM - 24-5-2019 at 18:08

There is another kind of strapping tape that I used when I worked in shipping back in the 1980s which was even stronger.

Can't recall the brand, but it had fibers that were exclusively parallel to the direction of the roll, and the entire width of the tape was reinforced with fibers about 1/4 mm apart or perhaps closer.

That tape was an inch wide and would support 90 Kg (tested by the simple expedient of lifting myself off the ground by pulling a piece of it)

Wish I could remember the brand.
I'm posting this on the off chance that somebody else might remember it and know the brand.

Edit: Looking around a bit on the interwebs I see what looks like the tape I used is called filament strapping tape, and Wikipedia claims some brands have a tensile strength of up to 600 per inch of width which is much more than whatever brand I was using.

Of course, it's only strong in one direction though...



[Edited on 25-5-2019 by SWIM]

twelti - 24-5-2019 at 19:28

Those ones ARE parallel to the roll. It is interesting in that I wonder if it would have an effect in directing the blast axially, if it is only strong laterally.

I do also have some where the fiberglass runs is both ways too.

I wonder how the containment compares to carbon arrow tubes or thin wall aluminum tubes?

[Edited on 25-5-2019 by twelti]

Simoski - 24-5-2019 at 21:11

So wants the idea twelti?
Get plastic tubing, press in the primary and confine with the tape?

If so then yes, do it. Maybe start with clear PVC fish tank tubing, cut a piece to size, melt 1 end shut, press in your primary / DDT mix and confine with the tape. It will work.

twelti - 25-5-2019 at 08:24

Quote: Originally posted by Simoski  
So wants the idea twelti?
Get plastic tubing, press in the primary and confine with the tape?

If so then yes, do it. Maybe start with clear PVC fish tank tubing, cut a piece to size, melt 1 end shut, press in your primary / DDT mix and confine with the tape. It will work.


I hadn't thought of plastic tubing, I was thinking of any thin paper tube that is just a substrate for the tape. Wouldn't the PVC tubing be too "balloony", i.e. stretchy?

Laboratory of Liptakov - 29-5-2019 at 22:14

Maybe it's time try any fiberglass tape. With any substrate core. Paper or plastic. And not just talk about it.....:cool:---LL

twelti - 29-5-2019 at 22:44

I have used it on the last few caps, but I dont have a good way yet to test the relative merits. One could compare the tensile strength of this tape and its weight to the tensile strngth and weight of, say, aluminum.