[Nhcoll-l] PTFE

[Dirk Neumann]

Hi Tonya,

maybe two things to consider here: PTFE is rather inert (stable against 
ethanol and formalin) and a good oxygen barrier; some collections in 
Europe use PFTE liners that are sold by a Swiss based vendor. The key 
question for me would be how thick the liner (?) is; PTFE can be a good 
gasket, if thick enough (i.e. > 0.2 mm)  to avoid damages from 
compression / repeated opening & closing.

The more relevant question for me would be the lid material itself; if 
the PTFE liner should be used with metal lids, it still might trap some 
vapours and moisture between lid and fluid if it is a PTFE inlay or 
(extra) internal gasket inside screw-on lids; this could trigger 
corrosion of the lids - besides all good properties of the PTFE. So good 
quality HDPE or PP plastic lids might be a better choice. Besides all 
this, I would strongly recommend to look into standardised lid sizes - 
this is surely one of the main lessons that can and should be learnt 
from the famous Copenhagen jars: in many fluid collections, the lids 
approach the end of their life span, but can't be replaced easily 
because they were not standardised and the original producer is no 
longer available. Standardised lids are easy to maintain and cost and 
time efficient if they have to be replaced.

Hope this helps,
with best wishes to the other side of the globe
Dirk



Am 21.05.2020 um 04:51 schrieb Haff, Tonya (NCMI, Crace):
>
> Hi all,
>
> I wonder if you all could please give me your opinion on the use and 
> archival nature of PTFE plastic? It is in the lids of some jars we are 
> considering purchasing for use in our EtOH collection, and I see that 
> it is used with chemicals and in scientific settings, but I have not 
> yet heard of it used in a museum setting. Any advice or thoughts would 
> be appreciated!
>
> Cheers,
>
> Tonya
>
> ---------------------------------------------------------
>
> Dr Tonya Haff
>
> Collections Manager
>
> Australian National Wildlife Collection
>
> National Research Collections Australia, CSIRO
>
> Canberra, Australia
>
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>
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-- 


Dirk Neumann

Tel: 089 / 8107-111
Fax: 089 / 8107-300
neumann(a)snsb.de

Postanschrift:

Staatliche Naturwissenschaftliche Sammlungen Bayerns
Zoologische Staatssammlung München
Dirk Neumann, Sektion Ichthyologie / DNA-Storage
Münchhausenstr. 21
81247 München

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http://www.zsm.mwn.de/sektion/ichthyologie-home/

---------

Dirk Neumann

Tel: +49-89-8107-111
Fax: +49-89-8107-300
neumann(a)snsb.de

postal address:

Bavarian Natural History Collections
The Bavarian State Collection of Zoology
Dirk Neumann, Section Ichthyology / DNA-Storage
Muenchhausenstr. 21
81247 Munich (Germany)

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