A Curators viewpoint.. But as some regard their rubber bits and Vinyl as precious.
Useful ?
http://canada.pch.gc.ca/eng/1439925170961
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A Curators viewpoint.. But as some regard their rubber bits and Vinyl as precious.
Useful ?
http://canada.pch.gc.ca/eng/1439925170961
Yes. Good subject. Ageing and deterioration of plastics and rubber (synthetic or organic) is certainly an issue.
Agree - especially the use of rubber in the idler wheels of turntables, the pressure wheel of reel-to-reel tape machines, and the decoupling bushes of some pick-up arms, as well, of course, in the cantilver suspension of cartridges.Quote:
Originally Posted by walpurgis
Interesting Danilo thanks for posting
Pinch rollers on R2R certainly can suffer from Hardening or softening, solvents normally get the blame but its interesting that UV, oxygen and humidity can also start this deterioration process
Alan
Good general info.
Surprised plasticizers were barely mentioned, especially from the nature of the source.
People wrap a lot of things with cling film, to protect them when storing/transporting etc and it is full of the stuff, though the amount varies by brand, if its very stretchy and sticks to itself really easily, the level will be high.
A friend was transporting half a meter of 100mm dia Polycarbonate bar in the boot of his car for me, expensive stuff and he didn't want to damage the mirror polished surface, so he wrapped it in cling film. When he took it out of the car the next day and unwrapped it, to his horror and mine it was destroyed. The surface was heavily crazed and pitted, but worse were the many (100's) of stress cracks running radially to a depth of 10 to 15mm. I knew it attacked this type of material, but I was surprised how quickly it had done its work. So avoid contact with those TT dust covers if they are Polycarb.
A lot of people use cling film in microwave ovens when re-heating food, do they even read the instructions? When the film is heated the plasticizers can be released and transferred on contact, its ok I suppose if the film isn't touching the food, but otherwise its a no no. You don't want to be eating plasticizers, I NEVER use cling film in the microwave.
So glossing over plasticizers is a bit of an omission, but the whole subject of plastic ageing and degradation is a complex one and you could fill a book on it, so within the scope of the article its understandable.
Things like sun screen and insect repellent are horrible when it comes to certain common plastics. We used to do a quick test on components, using Avon sunscreen with built in mozzy repellent, as used by US armed forces etc, one of the most corrosive household substances I have come across. If the product would stand up to this, it would sail through all the proper testing down stream. One application would literally eat its way through a 3mm ABS case in two to three weeks. As we were developing items for military and aero space applications that would have been a problem. :rolleyes:
UV is a problem on many types and especially in plasticized grades, hence UPVC for window frames etc (U = Un-Plasticized). A new Polyprop bucket is robust and will take a lot of knocks, leave it out in the sun for a few weeks and then kick it in the evening when it has cooled down, it will shatter into hundreds of bits.
In many ways, older products using low tech materials will outlast modern products, at least they are easier to repair and keep running, in most but not all cases.
Oh yes - the amount of damage 'neat DEET' (diethyltoluamide, an insect repellant) can do to other plastics has to be seen to be believed. Ironically I found it completely ineffective in repelling mosquitos! :doh:Quote:
Originally Posted by Qwin