What are the main factors that determine how much load is put on the material/how strong it has to be? On the one hand I read how balloon fabrics even on smallest piloted hot air balloons are advanced rip-stop multi layered high tech stuff that's also not cheap but then on the other some generic PET film turns out strong enough to lift a man with only 25 micron thickness - that's thinner than some trash bags!
$\begingroup$
$\endgroup$
2
-
$\begingroup$ How much safety margin do you want? $\endgroup$– Eugene StyerOct 13, 2022 at 14:35
-
$\begingroup$ So, you have some relatively small pressure differential between inside and outside that you have to maintain, so the material needs to be strong enough to withstand that. Then you have the suspension of the weight distributed to the surface most likely via some netting, so the envelope material needs to be able to withstand those focused point loads. But then you have other engineering objectives: Porosity limits. Durability and service life, including rip-stop. Field repairability. Weight. Cost. Stowed size. UV, flame, chemical, sediment resistance. Rain absorption. $\endgroup$– Max ROct 14, 2022 at 1:36
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
In ASTM F2355-14, "structure requirements for ... balloons ... are presented in details." I haven't bought a copy of that specification myself, but someone who has could quote those details here.
answered Oct 13, 2022 at 18:06