[Nhcoll-l] Jar liners

Fri Nov 20 04:08:51 EST 2020

Hey there,

I totally agree with Dirks statement. Glass lids are much more stable than any other kind of material used in fluid collections.

I would like to share my experience with a sort of new jar type from Duran® (former Schott). They have a product line called "GLS 80" jars. It has a mouth opening of 80 mm, but the size varies from 500ml to 25000 ml. The mouth opening works very well for smaller specimens.

The jars are made of borosilicate and sold at an affordable price, because they are made for the pharma industry. This is why they also have "filling marks", which esthetically speaking is not so nice, but it still fulfills the purpose of the jar. One of the sales agents of DWK (Duran Group), offered me that at a certain amount of jars, there could be a batch (around 1000 jars) made without "filling marks".
There is a new type of lid for this jars too, made of Polysulfone (PSU) with a PTFE coated silicone liner.

The Duran Group works worldwide, so if you have any questions regarding this contact Eric Lehnen (eric.lehnen at dwk.com<mailto:eric.lehnen at dwk.com>). He knows about the use of the jars for collections purpose.

This seems to be a very good improvement to move away from poor quality "sausage jars" with fast degrading lids.

I have made a one year aging test with three jars with ethanol 70% mixed with a buffered formaldehyde solution 3,4% (9:1) and have seen no negative reactions on the lids. But this still should be tested more thoroughly.

Hope this helps you out!

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Von: Nhcoll-l [mailto:nhcoll-l-bounces at mailman.yale.edu] Im Auftrag von Dirk Neumann
Gesendet: Freitag, 20. November 2020 09:10
An: nhcoll-l at mailman.yale.edu
Betreff: Re: [Nhcoll-l] Jar liners

Hi Tonya & Lennart,

I guess there are several layers to unfold here:

Foamed liners - like the F217 liners you mention - consist of a foamed cell structure which - if the lid is screwed down tight - is compressed again the neck of the jar. This outs the cells under pressure and closed cells would withstand this tension better then open cell structures. It is hard to tell if the F217 liners you mention has open or closed cells, which gas is used for filling of the foam structure, etc. Even if the F217 liners would have the right composition, right thickness, closed cells - it still a is compressible gasket which has a limited life span.

To produce a good closure, you would further need to consider the threads on the jar (continuous or not), the composition of the lid itself (the best liner does not help if the plastic used for the lid itself is of poor quality, etc. Most important seems to me that sizes of such lids are standardised (rather then customised for specific jars), so that they can easily be replaced if they fail. This is one of the huge problems many collections with Copehagen jars now face after plastic lids reached the end of their life span, sized where customised, company went out of production: it is virtually impossible to replace these lids - which causes huge problems in many collections.

It seems that F217 and PTFE liners are often used as inlays for Phenolic caps (Bakelite) - which is a no-go in fluid collections because this sort of thermoset plastics is easily degraded by residual formaldehyde escaping from formaldehyde preserved specimens, even if they have been transferred in to alcohol. As said: the best liner is worthless if the plastic lid itself is unsuited.

In general, plastic lids are not a good oxygen barrier - this is also worth remembering, especially if specimens inside such jars release a lot of fats or oils.

Rather then concentrating on specific lids I would look into jars that are designed for the pharmaceutical sector. Here, both the jar (soda-lime glass) and the lid are expected (and usually tested) to withstand a wide range of chemicals AND to provide a good barrier against oxygen.

There are different suppliers of such jars, the disadvantage of the wide mouth jars however is that the largest opening in these jars is 65 mm. So a good option for for 100 - 1000 ml jars, but not for larger jars.  Stölzle (who also produce high quality borosilicate stoppered jars) is a possible source for such jars, but there are many others as well: https://pharma.stoelzle.com/en/product_category/weithalsglaser/

So as mostly no clear cut answer, but hopefully one that is useful.

All the best

Dirk

Am 20.11.2020 um 00:29 schrieb Haff, Tonya (NCMI, Crace):
Hi all,

I know I've asked about this before, but may I please clarify again.... Does anyone have preference regarding PTFE (e.g. Teflon, I believe) lid liners vs F217 liners, which are layered polyethylene (as far as I understand). Can anyone give me advice as to what would be better as a lid liner for specimens kept in 70-90% EtOH? Advice very appreciated!

Cheers,

Tonya

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Dr Tonya Haff
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