I have a coil of flexible PVC tubing that has sat on a shelf for a few
years and I went to cut a piece from it and found that the entire coil
seems to be covered in an oily film. Nothing else in the area has this
film so it would seems it hasn't been deposited from the environment so
I assume the tubing has exuded this oily film itself. Does anyone know
if this is a normal occurrence with PVC tubing and is this some sort of
plasticiser leaching from the tubing. If so any thoughts on whether this
is detrimental for the tubing. I saw some of the tubing earlier today
that I had supplied to someone a few years ago and that seemed fine but
maybe general handling will have removed anything exuded so as not to be
noticed. Any thoughts appreciated.

On Sat, 08 Dec 2012 20:37:30 +0000, the renowned David Billington
wrote:

I have a coil of flexible PVC tubing that has sat on a shelf for a few
years and I went to cut a piece from it and found that the entire coil
seems to be covered in an oily film. Nothing else in the area has this
film so it would seems it hasn't been deposited from the environment so
I assume the tubing has exuded this oily film itself. Does anyone know
if this is a normal occurrence with PVC tubing and is this some sort of
plasticiser leaching from the tubing. If so any thoughts on whether this
is detrimental for the tubing. I saw some of the tubing earlier today
that I had supplied to someone a few years ago and that seemed fine but
maybe general handling will have removed anything exuded so as not to be
noticed. Any thoughts appreciated.

Yeah, flexible "PVC" can be 1/3 plasticizer, which is more volatile
than the polymer itself. Unike some things, plastic tends to get
stiffer as it ages.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
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"David Billington" wrote in message
...
I have a coil of flexible PVC tubing that has sat on a shelf for a
few years and I went to cut a piece from it and found that the entire
coil seems to be covered in an oily film. Nothing else in the area
has this film so it would seems it hasn't been deposited from the
environment so I assume the tubing has exuded this oily film itself.
Does anyone know if this is a normal occurrence with PVC tubing and
is this some sort of plasticiser leaching from the tubing. If so any
thoughts on whether this is detrimental for the tubing. I saw some of
the tubing earlier today that I had supplied to someone a few years
ago and that seemed fine but maybe general handling will have removed
anything exuded so as not to be noticed. Any thoughts appreciated.

http://en.wikipedia.org/wiki/Dibutyl_phthalate
http://en.wikipedia.org/wiki/Di(2-ethylhexyl)_phthalate

jsw