Hi Steve, I wonder if there is any way these could be parylene coated after assembly. That should extend their shelf life quite nicely. KennyB -----Original Message----- From: Steve Kelly [mailto:[log in to unmask]] Sent: Tuesday, July 14, 2009 2:12 PM To: [log in to unmask] Subject: Re: [TN] Storage life for rigid flex Hi Inge, Thank you - good common sense. I can work with this. Regards Steve -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Inge Sent: July-14-09 5:08 PM To: [log in to unmask] Subject: Re: [TN] Storage life for rigid flex Steve, I think there would be no problem with the storage in itself, however, what happens when the part is to be used after 20 years. It might depend, as a certain person use to say, parts are used differently. A part that is vibrating or is part of moving function will react to small changes more than a 'stiff' one. I have seen flexes with sharp bends delaminate after long use. On the other side, non movable and fixed flexes in e.g. cameras seem to live for ever. And finally an example from a copiator used in one of our vehicles for 'desert' use. The machines had been half filled by sand, had been frequently used and under awful conditions. There was absolutely no problem with the large flex that operates the head. So, PI is very tough. The answer to your question is probably dependant of the application. Interesting case, I recognise your situation. Missiles, grenades and a lot of other mil stuff is often stored for many years, and are supposed to work instantly despite the long storage time. In such cases, there will be little wear with operational time only seconds or minutes and hence no problems. I suppose you get the best information from the PI manufacturers themselves. Would be surprised if someone at TN can give a real safe answer to your q. Good Luck. Who seekest will find. /Inge --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------