Hello safety experts,
In relation to my post a month or so ago about battery fire enclosures w.r.t. EN 62368-1 I wondered about using polyimide tape to provide a fire enclosure for a battery. The idea being to wrap the tape around the battery, at least once, probably twice. Suitable materials could include: * DuPont Kapton <https://www.dupont.com/content/dam/dupont/amer/us/en/ei-transformation/public/documents/en/EI-10142_Kapton-Summary-of-Properties.pdf> (UL file E39505) states V-0 for 25um thick * Muller Alhorn Norton TH <https://www.mueller-ahlhorn.com/wp-content/uploads/2024/02/Norton-TH-FI-16011-ENG.pdf> (UL file E231847 <https://iq.ulprospector.com/en/profile?e=599035> ) states V-0 for 25um thick Tapes vs film Plastic material is tested to UL 94 but tapes are tested to UL 510. Therefore, as soon as you put a self adhesive backing on a UL 94 V-0 rated film, even if the material doesn’t change, the material now needs testing to UL 510. As far as I can tell, the test methodology between the two standards are not comparable. I feel like there is no reason that adding a small amount of adhesive on the back would significantly change the flammability characteristics. The alternative “by the book” method would be to wrap the battery in the polyimide film and secure with some regular polyimide tape on the outside 😊 Vertical Burning vs Thin Material Vertical Burning The tests appear to be fundamentally similar in terms of sample size and flame power, just the wrapping of the thin material sample around a supporting mandrel. It looks like V-0 and VTM-0 ratings are comparable in this respect. As always, I would appreciate your thoughts on the matter, particularly in pointing out any problems in logic or understanding on my part. References UL 94 UL 510 This link also discusses some of the same <https://www.cmc.de/en/ul-listung> (If only we had a vertical burning test rig and we could try out some of these ideas…) All the best James James Pawson Managing Director & EMC Problem Solver Unit 3 Compliance Ltd EMC : Environmental & Vibration : Electrical Safety : CE & UKCA : Consultancy <http://www.unit3compliance.co.uk/> www.unit3compliance.co.uk | <mailto:[email protected]> [email protected] +44(0)1274 911747 | +44(0)7811 139957 2 Wellington Business Park, New Lane, Bradford, BD4 8AL Registered in England and Wales # 10574298 Office hours: Every morning my full attention is on consultancy, testing, and troubleshooting activities for our customers’ projects. I’m contactable between 1300h to 1730h from Monday to Friday. For inquiries, bookings, and testing updates please send us an email on <mailto:[email protected]> [email protected] or call 01274 911747. Our lead times for testing and consultancy are typically 4-5 weeks. - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to [email protected] All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/[email protected]/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: [email protected] Rick Linford at: [email protected] For policy questions, send mail to: Jim Bacher: <[email protected]> _________________________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
