Air-tight, High Specific-Strength Textiles

[Daniel Sellers]

I am an undergrad student working on a personal research project involving aeronautics. For the purposes of my project I have found that I need a fabric with a specific strength (tensile strength over density) of greater than 130 kNm/kg which is can be made air-tight.
Kevlar, Zylon and Spectra fibers are among the few textiles I've found which meet the strength-to-weight requirements.
I have seen reference to zylon and spectra being used in parachute and sail materials and I was hoping someone here could give me more information (any and all information would be appreciated) regarding how these materials are made to be completely air-tight and/or what materials need to be added to them to do so.
Thanks!

 

[CWatters]

What do they use for car airbags? Space suits?

 

[Daniel Sellers]

Air bags use woven nylon and space suits use a number of different materials including kevlar and nylon.
The issue is that nylon is not strong enough compared to its density. Perhaps I need a layered nylon/kevlar material as well

 

[Nidum]

Hyperlast

 

[JBA]

The suggested Hyperlast site is also a good primer on the types of materials for applications similar to that in which you are interested.

 

[CWatters]

As I understand it high tech sails use a laminate of woven and sheet materials. Will affect the strength/weight ratio though.

 

[Baluncore]

There are three things to combine.
1. A high strength fabric.
2. A film to make it airtight. Consider Mylar, high strength biaxially oriented PET film.
3. An external protection layer such as metallisation to increase lifetime in UV.
This page covers several points. https://en.wikipedia.org/wiki/BoPET#Manufacture_and_properties