NIce Hybrid Material

[cannon freak]

I was watching television the other day and seen a little clip on how they shoot up fireworks in some of the large amusement parks, but my question is what is the pipe that is used to house the fireworks when they are shot off? I’m just asking this because they use black powder to shoot it out, about a 7 pound ball 300 feet straight up, so it has to be some very strong material. So if anyone could tell me it would be appreciated.

[benstern]

Actually, it is just High-density polyethylene (HDPE)!
http://skylighter.com/mall/plastic_mortar_tubes.asp

For the larger shells, they actually buy the tubes in the ground to make them almost indestructible.

[cannon freak]

Hey if you were to encase a hybid in about 3 inches of conctreate do you think it would make it capable of widthstanding much higher pressures, or would the concreate be cracked and fly off due to the shock of the exsplosion.
I know that it would not be very manuverable, or very practical but it would be awsome to fire.

[FiveseveN]

About the fireworks: Cardboard tubes are also used (single use and only up to 5''), and I've seen HDPE up to 1' ID being used.
As for concrete... there's more than one kind, and if you don't mix it well chances of cracks increase. I think using steel would be a better idea.

[ammosmoke]

They generally use HDPE tubes, and steel. However, steel is not usually recommended for shells because if they fail to lift, the steel fragments all over the place. If it blows in the HDPE, it just cracks and splits, venting the pressure instead of fragmenting. Also, artillery shells use MUCH coarser grain powder (lift powder) than what they would use for a 9mm for instance. Sure, it creates lots of pressure, but less than fine grain powder. If they were to fine grain powder instead, it would blow up every time because of the faster burn rate.