Hydraulic pressure resistance

DAVID DIAZ DIAZ

I need to build a customized hydraulic pressure resistance tester in the lab. The idea is to measure easily but with a good reliability the resistance to hydraulic pressure (either external pressure on the water drops or the pressure caused by a column of water for example) of different paper surfaces. The commercial available testers in the market are very expensive, so any suggestion would be very appreciated.

Thank you very much, DDD.

mgb_phys

Do you mean hydrostatic pressure?
That is what column height of water a material can support - as quoted on expensive waterproofs?

Easiest way is probably a very tall plastic tube full of water with a scale on the side.
If you don't have a high enough room then a shorter tube, sealed at the top and a bike pump to presurise the air above the column of water would probably work.

DAVID DIAZ DIAZ

Thanks!

Yes, my aim is to improve the hydrostatic pressure resistance of different paper coatings, and I need an easy method to compare this resistance for different paper sheets.

If I understand you well you would attached somehow the paper sheets to the bottom of the column with some container bellow, and then fill the column with water from the top and see when the paper is broken? maybe I missunderstand your design.

Would it be possible you send me by email a quick draw of the system you have in mind? ddiazdiazster@gmail.com

DAVID DIAZ DIAZ

The paper surface is superhydrophobic. However, the external pressure on a drop of water (or a column of water) can destroy the superhydrophobic property and then the water will penetrate into the paper. So, what I'm trying to do is to compare different paper surfaces and see which one is more resistan to the water pressure.

mgb_phys

Yes, thats the system used to test waterproof clothing material ( I live in Vancouver!), you stretch a piece of the material over the open bottom end of the tube and hold it in place wiht a clamp. You then fill the column until it leaks. Of course you might need a column several metres high so a more practical arrangement is a 1m high column with a sealed top and an air space above the water, you can pump compressed air into the top to increase the effective water pressure.

DAVID DIAZ DIAZ

I live in Switzerland! so I guess the waterproof clothing idustry here would love also the idea!

My only doubt is how to accurate control the water pressure. I guess I can find some pump compressed air that give me a lecture of the pressure I'm applying ...

Thanks!
DDD

mgb_phys

Each extra bar ( atmosphere) of pressure is equal to 9.8m height of water.
You probably only need something like a car foot pump with a pressure guage.

DAVID DIAZ DIAZ

Thank you!
DDD