Recent content by Laurencet

Be great to put some numbers behind this.. Assuming the balloon is made from 2 discs 50cm diameter We have an area of approximately 4000cm² Pressure 0.1bar (75 Torr) above the atmosphere? If we forget everything else in the foil lamination apart from the Alu - Thicknesss 10μm How do we...

https://m.tau.ac.il/~tsirel/dump/Static/knowino.org/wiki/Compressibility_factor_(gases).html I just worked through the above method example calculating "a" "b" and Vm to calculate Z This gave me a z of 0.389 and a final density of 205.4kg Further away than the method you used. Is there more...

Thankyou for your answers great to see you came up with the same answer. Do you have a link for where on the NIST website? I searched for XE on the NIST website and came up with 5109 documents... too many to read through. I came up with 201 kg so very close, is there a good website or paper...

Very interesting... I'm going to have to put some numbers into the equation, I'm now wondering if there is a critical thickness for aluminium for diffusion to take place. C. J. Smithells, C. E. RANSLEY Published in Nature DOI:10.1038/134814b0 THE rate of diffusion of gases through metals...

How do I calculate the density of a supercritical fluid? If I have 100 Litres of Xenon at 23°C and 150bar, What will the Xenon in the tank weigh? The phase diagram is here https://encyclopedia.airliquide.com/xenon

All metals have zero permeability, as the foil starts to get below 12nm we start to get faults and holes in the foil that allow for permeability.

I'm surprised no one can answer this question..

The units I quoted are I'm guessing its products where you need to stop the water vapour and oxygen to keep it fresh for longer. I still don't understand why foil helium balloons don't last longer.

Latex balloons do well to last a day, helium is so tiny it just goes straight through. you can buy an additive to add to latex balloons called Hi-float that makes them last a few days but never a year. The helium can definitely go through the mylar ( I have a permeability coefficient of...

Why do metalised film helium balloons only last about a week? Could I improve this result and make a balloon float for a year? (and don't cheat and say just make it bigger) how do I stop it leaking? Are there any better materials to make it from? (unlimited budget) As I understand aluminium...