On Tue, 25 Oct 2016 12:00:08 +0100, N_Cook wrote:

Do you happen to know what causes contangion in rubber ?
If one band fails by stretching or going gooey, then the others usually
are failing in the same way. I'm assuming they are not of the same batch
at manufacturing and then the same ageing failure but some gas or
biological vector moving about inside a casing

Sorry, no clue. I have seen the problem, but simply assumed that
there was some kind of gaseous attack on the rubber and that all the
rubber parts were equally affected. This might offer a clue as to
what is happening:
https://en.wikipedia.org/wiki/Tire_recycling#Tire_pyrolysis
However, I don't see how heating in an oxygen free environment
explains the deterioration found in consumer electronics.

I really wished that I knew the mechanism, because I could then make a
fortune devulcanizing rubber automobile tires and recycling the
resultant "goo" into new tires.
https://en.wikipedia.org/wiki/Vulcanization#Devulcanization

Incidentally, there are bacteria that eat rubber:
https://en.wikipedia.org/wiki/Vulcanization#Microbial_degradation
http://www.rubbernews.com/article/19950710/ISSUE/307109993/tire-eating-bacteria-under-study
and eat other hydrocarbons (plastic, fuel, sewage, etc):
https://en.wikipedia.org/wiki/Microbial_corrosion
or the nightmare of having our plastics dominated civilization eaten
alive by GMO bugs:
http://www.extremetech.com/extreme/224678-plastic-eating-bacteria-set-to-revolutionize-waste-disposal
http://www.sciencealert.com/new-plastic-munching-bacteria-could-fuel-a-recycling-revolution

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558