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Homemade Shell Wrapping Machine


Raceman17

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For cylinder shells in particular I would advise against the use of reinforced paper for a few reasons, namely:

 

1) Cylinders derive much of their structural integrity from the spiking. While spiking provides confinement when the shell breaks, it also provides some multiaxial compression, which gives the shell enough strength to withstand lifting.

 

2) Fiber reinforcement increases the tensile strength of the paper, but the paper is not applied in a uniform manner to the cylinder shell. The use of reinforced paper would complicate shell design if break symmetry was an objective. In a cylinder shell, paper is concentrated circumferentially, so how would longitudinal confinement be achieved?

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In most cases the reinforced paper is actually too strong. It's easy to overdo it, and can venture into a territory where the shell may have have enough break confinement but not sufficient physical integrity.

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Another concern is that the papers and natural glues, and cotton or jute strings traditionally used in fireworks are biodegradable, whatever the reinforcement of the tape may not be.

 

While fireworks obviously has a carbon footprint (and other green terms) there is little reason to go dropping surplus plastic thread or sheets wherever we have fired things.

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I concur with you Arthur and actually reached the same conclusion myself.

 

I additionally questioned the plastic taking fire and burning on the ground. This forum has severed me well in discouraging even building a few experimental shells with the reinforced draft. Thanks!

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