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<p><font size="2" face="sans-serif">According to the Product Data Sheet from TriSeal, the seal mentioned by Jean-Marc, F-217 PE Seal, is a three-ply co-extruded liner consisting of a foamed Low Density Polyethylene (LDPE) core sandwiched between two layers of solid Low Density Polyethylene (</font><a href="http://tri-seal.tekni-plex.com/sites/default/files/tds_tri-seal_f-217_-_rev5.pdf"><font size="3" color="#0000FF" face="serif"><u>http://tri-seal.tekni-plex.com/sites/default/files/tds_tri-seal_f-217_-_rev5.pdf</u></font></a><font size="3" face="serif"> </font><font size="2" face="sans-serif">)</font><font size="2" face="sans-serif">. This is different from the liner described by Paul as made from polyethylene foam. The presence of the solid LDPE layer adjacent to the contents will greatly change properties of the liner such as extractability of additives, strength, resistance to tear when cap is twisted on, sealability, etc . We may be discussing different products, not just different batches of the same product. This demonstrates the need for extreme precision when describing and ordering products. Product differences, especially if these include structural differences, are probably more significant than batch differences. </font><br>
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<font size="2" face="sans-serif">My experience during investigations of adhesive and adhesive tapes has been that seldom are there significant batch differences in products from large primary manufacturers. After all these manufacturers are supplying products to many secondary converters who rely on and demand that properties do not change. Therefore, the primary manufactures tend to be very careful to maintain properties. Also, because manufacturing processes usually are quite delicate processes with complicated interactions of sub-processes, it is usually quite difficult and expensive to change the manufacturing process, including the raw materials used to make the product. Usually when this is done, a new product is produced, usually with a new product number or process number, new properties are published, and the new product is described as a substitute or replacement for the old. This is not the case with secondary converters who assemble various manufacturer's products into a finished product. Here the demand on the converter is to produce a final product with consumer defined properties. The converter tends use whatever is available and economically advantageous to reach that goal. Usually the customer does not care what is used to make his product, just that the product does the job desired in his application. Since the converters product still does the same job, his product name probably does not change, even though the constituents may have. A common occurrence of this is the adhesive on self-adhesive consumer (not technical) products. </font><br>
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<font size="2" face="sans-serif">I do not know about Paul's liners but TriSeal F-217 mentioned by Jean-Marc is a technical product, with very tight specifications (and approvals) from Food and Drug regulators, certainly for constituent polymers and additives, and perhaps for performance factors such a sealing ability. This approval probably disappears if the product composition or structure changes. Therefore we can expect uniform batches. Unfortunately it is always important to keep in mind that the shelf life expected by the manufacturer for his products may be much shorter than what we want. For example, TriSeal may only expect (and guarantee?) their liners to last for a few years in a consumer product like cosmetics or drugs (which always have expiry dates), and not the decades we want. </font><br>
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<font size="2" face="sans-serif">All this considered, it must be stated that 20 years of successful application of the F-217 seal at CMN is a good evidence that this product is performing well in a pretty harsh application. I wonder if TriSeal would be surprised to hear this?</font><br>
<br>
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<font size="2" face="sans-serif">R. Scott Williams<br>
Senior Conservation Scientist (Chemist), Canadian Conservation Institute<br>
1030 Innes Road, Ottawa, Ontario, Canada K1A 0M5<br>
tel: (613) 998-3721<br>
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email: scott.williams@pch.gc.ca</font><br>
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<img width="16" height="16" src="cid:1__=0ABBF0DEDFC24F808f9e8a93df9386@pch.gc.ca" border="0" alt="Inactive hide details for Jean-Marc Gagnon ---2012-08-01 08:14:36 AM---Paul, At the Canadian Museum of Nature, we have been usi"><font size="2" color="#424282" face="sans-serif">Jean-Marc Gagnon ---2012-08-01 08:14:36 AM---Paul, At the Canadian Museum of Nature, we have been using F217 PE Seals for a good 20 years and hav</font><br>
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<font size="1" color="#5F5F5F" face="sans-serif">From: </font><font size="1" face="sans-serif">Jean-Marc Gagnon <JGagnon@mus-nature.ca></font><br>
<font size="1" color="#5F5F5F" face="sans-serif">To: </font><font size="1" face="sans-serif">"'Paul Callomon'" <callomon@ansp.org>, "NH-COLL listserv (nhcoll-l@mailman.yale.edu)" <nhcoll-l@mailman.yale.edu></font><br>
<font size="1" color="#5F5F5F" face="sans-serif">Date: </font><font size="1" face="sans-serif">2012-08-01 08:14 AM</font><br>
<font size="1" color="#5F5F5F" face="sans-serif">Subject: </font><font size="1" face="sans-serif">Re: [Nhcoll-l] Potential problem with older PE jar lid liners</font><br>
<font size="1" color="#5F5F5F" face="sans-serif">Sent by: </font><font size="1" face="sans-serif">nhcoll-l-bounces@mailman.yale.edu</font><br>
<hr width="100%" size="2" align="left" noshade style="color:#8091A5; "><br>
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<font size="2" color="#1F497D" face="Calibri">Paul,</font><br>
<font size="2" color="#1F497D" face="Calibri"> </font><br>
<font size="2" color="#1F497D" face="Calibri">At the Canadian Museum of Nature, we have been using F217 PE Seals for a good 20 years and have not observed deterioration. This is not to say that we have checked all lids with such gaskets installed since that time, but we have had the opportunity to open quite a few.</font><br>
<font size="2" color="#1F497D" face="Calibri"> </font><br>
<font size="2" color="#1F497D" face="Calibri">As Stott Williams indicated, there may certainly be differences between batches, as it’s been for instance observed for batches of Ethafoam and other closed-cell polyethylene products.</font><br>
<font size="2" color="#1F497D" face="Calibri"> </font><br>
<font size="2" color="#1F497D" face="Calibri">While it is still hard to predict the long-term durability of PE seal, the use of a good sealing tape around the lid can certainly serve to at least partly mitigate this problem and insure the preservation of the collection specimens (Steigerwald, Michele and Sylvie Laframboise, 1996. Tape application: a jar sealing method for reducing ethanol evaporation in fluid-preserved collections. </font><font size="2" color="#1F497D" face="Calibri"><i>Collection Forum</i></font><font size="2" color="#1F497D" face="Calibri"> 12(2): 45-53).</font><br>
<font size="2" color="#1F497D" face="Calibri"> </font><br>
<font size="2" color="#1F497D" face="Calibri">Jean-Marc</font><br>
<font size="2" color="#1F497D" face="Calibri"> </font><br>
<font size="1" color="#1F497D" face="Arial">Jean-Marc Gagnon</font><font size="1" color="#008000" face="Arial"><b>, </b></font><font size="1" color="#008000" face="Arial"><b>Ph.D.</b></font><br>
<font size="1" color="#008000" face="Arial"><i>Past President (2012-2014) of the Society for the Preservation of Natural History Collections (</i></font><a href="http://www.spnhc.org/"><font size="1" color="#0000FF" face="Arial"><i><u>www.spnhc.org</u></i></font></a><font size="1" color="#008000" face="Arial"><i>) </i></font><br>
<font size="3" color="#008000" face="Times New Roman"> </font><br>
<font size="1" color="#008000" face="Arial">Curator / Conservateur des collections</font><br>
<font size="1" color="#008000" face="Arial">Invertebrate Collections / Collections des invertébrés</font><br>
<font size="1" color="#008000" face="Arial">Canadian Museum of Nature / Musée canadien de la nature</font><br>
<font size="1" color="#008000" face="Arial">P.O. Box 3443, Stn "D" / C.P. 3443, Succ. D</font><br>
<font size="1" color="#008000" face="Arial">Ottawa, ON Canada K1P 6P4</font><br>
<font size="1" color="#008000" face="Arial">T: 613-364-4066 / F: 613-364-4027</font><br>
<font size="1" color="#008000" face="Arial">E/C: </font><a href="mailto:jmgagnon@mus-nature.ca"><font size="1" color="#0000FF" face="Arial"><u>jmgagnon@mus-nature.ca</u></font></a><br>
<a href="http://www.nature.ca/"><font size="1" color="#008000" face="Arial"><u>http://www.nature.ca</u></font></a><br>
<font size="2" color="#1F497D" face="Calibri"> </font><br>
<font size="2" face="Tahoma"><b>From:</b></font><font size="2" face="Tahoma"> nhcoll-l-bounces@mailman.yale.edu [</font><font size="2" face="Tahoma"><a href="mailto:nhcoll-l-bounces@mailman.yale.edu">mailto:nhcoll-l-bounces@mailman.yale.edu</a></font><font size="2" face="Tahoma">] </font><font size="2" face="Tahoma"><b>On Behalf Of </b></font><font size="2" face="Tahoma">Paul Callomon</font><font size="2" face="Tahoma"><b><br>
Sent:</b></font><font size="2" face="Tahoma"> July-30-12 3:56 PM</font><font size="2" face="Tahoma"><b><br>
To:</b></font><font size="2" face="Tahoma"> NH-COLL listserv (nhcoll-l@mailman.yale.edu)</font><font size="2" face="Tahoma"><b><br>
Subject:</b></font><font size="2" face="Tahoma"> [Nhcoll-l] Potential problem with older PE jar lid liners</font><br>
<font size="2" face="Calibri"> </font><br>
<font size="2" face="Calibri">Colleagues,</font><br>
<font size="2" face="Calibri"> </font><br>
<font size="2" face="Calibri">I have today found a severely deteriorated jar lid liner in our alcohol collection. The liner is made from polyethylene foam. It was sold to us in 1999 and installed in 2000. The material has failed completely, with crazing and cracking of the surface and tearing along the compression face. The foam has become weak and powdery in places. The jar was filled with 70% ethanol.</font><br>
<font size="2" face="Calibri"> </font><br>
<font size="2" face="Calibri">The manufacturers have suggested that the use of this liner for long-term storage of alcohol is responsible for the deterioration. If this is true, the implications for our collection – we have about 20,000 bottles that use these liners – are potentially serious. </font><br>
<font size="2" face="Calibri"> </font><br>
<font size="2" face="Calibri">Does anyone have experience with this problem? Are Teflon liners a better alternative? </font><br>
<font size="2" face="Calibri"> </font><br>
<font size="3" face="Times New Roman"><b>Paul Callomon</b></font><br>
<font size="3" face="Times New Roman">Collections Manager in Malacology, Invertebrate Paleontology and General Invertebrates</font><br>
<font size="3" face="Times New Roman">The Academy of Natural Sciences of Drexel University</font><br>
<font size="3" face="Times New Roman">1900 Benjamin Franklin Parkway</font><br>
<font size="3" face="Times New Roman">Philadelphia, PA 19103</font><br>
<a href="mailto:callomon@ansp.org"><font size="3" color="#0000FF" face="Times New Roman"><u>callomon@ansp.org</u></font></a><br>
<font size="3" face="Times New Roman">Tel. 215-405-5096</font><br>
<font size="3" face="Times New Roman">ansp.org</font><br>
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