[pure-silver] Re: Problem with 2 tray hypo (fixer).
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sat, 5 Dec 2009 00:21:32 -0800
----- Original Message -----
From: "Nicholas O. Lindan" <nolindan@xxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Friday, December 04, 2009 2:07 PM
Subject: [pure-silver] Re: Problem with 2 tray hypo (fixer).
"Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
I got curious and wrote to S.C.Johnson, the maker of
Saran Wrap, to ask if any oxygen permeability tests were
ever made. I suspect they have but will know when they
answer. The same company also makes Zip-Lok bags and many
other products. Saran Wrap is polyethylene.
Saran wrap was made by Dow chemical. It was
polyvinylidene chloride (PVDC) and was impermeable to
pretty much everything. Saran is Dow's trade name
for PVDC.
The name "Saran Wrap" was sold to Johnson who uses it to
sell a completely different and badly performing product
in the US and Canada. It is now a polyethylene
wrap like Glad & Co, and is quite permeable - even
small bacilli can pass through it.
The product sold in the EU is (was?) still made from
PVDC.
The closest one can come to <real> Saran wrap is PVC
shrink-film wrap sold for meat packaging. I believe
Costco carries PVC wrap.
==
Nicholas O. Lindan
Cleveland Engineering Design, LLC
Cleveland, Ohio 44121
That explains why I found the S.C.Johnson statement
about the material puzzling. I did remember than Saran was
invented and sold by Dow but had only a vague memory of the
name of the material. We will see what is in their answer.
BTW they mention that they no longer used chlorine in the
wrap. Evidently this was a cause of enironmental problems of
some sort.
--
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you subscribed,)
and unsubscribe from there.
Other related posts:
