h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Up with elastane
Down with sagging dead jumpers!

From experience with cycling shorts and swimming trunks, Lycra does seem to have similar ageing properties to standard elastic, albeit on maybe a longer timescale - it stays functional for years, and then the entire garment gives up the ghost at once, and turns into a shpaeless rag.

Regarding potentially embarrasing body-hugging materials, I think my red silk underwear must come a close second.
Silk *thermal* underwear for caving, I hasten to add. Even the smallest trace of a beergut becomes blindingly obvious.

Just a few points.

Elastane is not resistant to chemical attack from Chlorine. This is the reason that it eventually gives up the ghost. To limit the effects, swimwear for example should be rinsed after use in a chlorinated swimming pool.

Elastane also ages under heat in a similar fashion to other rubbers, so care should be taken to follow the manufacturers instructions regarding drying. A hot tumble dryer will shorten a garments life considerably.

Elastane's impact on clothing and on Du Pont itself has been remarkable beyond even their wildest expectations. It is a commercial dream to come up with a product such as elastane.

Elastane is only 2% of the material used in the garment, so Du Pont only need to make a relatively small quantity each year, less than 100,000 tonnes. Other manufacturer's of elastane only push global production to around 200,000 to 250,000 tonnes per annum. By comparison Du Pont also make polyester at a rate of at least 1,000,000 tonnes per annum in a global market for polyester of more than 20,000,000 tonnes per annum (global consumption of all fibres man-made, synthetic and natural is slightly over 40,000,000 tonnes per annum).

Consumers are now very much aware of the benefits of elastane in garments and so demand is easily managed. Du Pont only have to keep the brand name in consumers awareness and they will sell all they can make. Other fibres are more cyclical as fashions waver largely between cotton and polyester. Elastane is blended with both with equal facility.

Elastane is produced in relatively small volumes, so it is not sold as a commodity like other fibres. Therefore the gross margin on sales is higher than with the other, higher volume fibres such as polyester. The net result is that Du Pont can reasonably aim to make as much money from elastane sales as from their total sales of polyester.

And best of all, elastane does degrade, so the consumer has to come back to buy some more!

This article could do with expanding to include some of the above points. All production figures are approximate, but firmly based on market data from the late 1990's through to 2001.

thank's for the info!
I can excite and amaze my friends

Madent! Potholer! Where were you guys when I put this through peer review? This entry would be vastly improved if it included your additional info.

And Hammythamster, I'll have you know that saggy dead jumpers have feelings too.

I don't particularly watch PR.

Are you doing any other fibres stuff.

http://www.bbc.co.uk/h2g2/guide/A654987
http://www.bbc.co.uk/h2g2/guide/A593732

These are the only other articles I know of.

That's kind of flattering, but I'm not sure I said anything hugely worthwhile - Madent is the one with the real knowledge.

Regarding PR, I'd looked in there a little in the past, but only really stared looking more often quite recently, after posting something of my own there.
Having now replied to some other entries in PR, I do visit more often, since one or other thread I've joined gets posted to by someone else, and I end up seeing other entries when I go to check out comments.

Regarding elastic materials in general, one thing I've found a little odd is how socks worn while soaking wet sometimes seem to get really baggy all over, but socks worn for a similar time on sweaty feet, which are certainly wet, if not actually dripping, lose little or no shape.
For example, if I wear regular thin cotton or cotton-rich socks underneath my thick walking socks or neoprene wetsocks on a long wet caving trip where I get my wellies full of water, when I take them off, they sometimes seem to be loose or entirely shapeless. Simple rinsing and drying doesn't do much, apart from making them very stiff, but they usually seem to recover partly or entirely after a machine wash.

I've just checked back with the data I have from last year.

Du Pont capacity 66,000 tonnes per annum
Total world capacity c 200,000 tonnes per annum

Elastane is produced by four methods:

dry spinning (80%)
melt spinning (13%)
wet spinning (5%)
reactive spinning (2%)

Production capacity is currently growing at an average of around 12% per annum.

A fair estimate suggests that 50% of garments produced worldwide contain elastane.

The above data were reasonably accurate for the first half of 2001.

Madent