Help identifying item,something like wool for the protection of electronics. - Page 1
Forum section: electronics / general

author: sotos
author_rank: Frequent Contributor
timestamp: September 14, 2012, 10:40:55 am
content: Help identifying item, it’s something like wool and is for the protection of electronic cards, electronic instruments, delicate gear and more.Can someone please tell me how it’s called and where I can find it?Thanks in advance.Sotiris.

author: T4P
author_rank: Super Contributor
timestamp: September 14, 2012, 12:40:23 pm
content: Isn't that the same stuff used for fish tank filters? I think it should be.

author: robrenz
author_rank: Super Contributor
timestamp: September 14, 2012, 12:44:20 pm
content: It looks like what would be called in the US "polyester batting" and can be found in places that sell sewing materials and supplies. also the stuff in most cheap pillows. The sheet material you are showing would be sold as a fill for making quilts.

author: Psi
author_rank: Super Contributor
timestamp: September 14, 2012, 12:55:08 pm
content: Also looks like the stuff they put inside speaker cases.

author: madires
author_rank: Super Contributor
timestamp: September 14, 2012, 01:17:42 pm
content: Quote from: Psi on September 14, 2012, 12:55:08 pmYep, it's damping wool for speakers. For protecting delicate gear most people use rigid foam.

author: Dawn
author_rank: Regular Contributor
timestamp: September 14, 2012, 02:53:51 pm
content: I've seen similar looking material by the roll in craft and fabric shops. Also try looking in an upholstry supply.

author: LEECH666
author_rank: Frequent Contributor
timestamp: September 14, 2012, 04:04:36 pm
content: Looks a little bit like this:http://en.wikipedia.org/wiki/Nonwoven_fabric(felt)In German this kind of fabric is called "Vlies" which coincidentally is pronounced like the English word fleece, which is also some kind of fabric (http://en.wikipedia.org/wiki/Polar_fleece). Both fabrics are different tho.Florian

author: G7PSK
author_rank: Super Contributor
timestamp: September 14, 2012, 05:19:56 pm
content: It is polyester felt.http://www.britishfelt.co.uk/acatalog/Admiral_Polyester_Felt.html?gclid=CJDUsf3JtbICFcQNfAod5R0ANwhttp://www.textileinnovations.co.uk/products/felt/

author: Fraser
author_rank: Super Contributor
timestamp: September 14, 2012, 05:51:14 pm
content: I used to sell it under the title "Baffle Wadding" for speaker cabinets as has already been stated.FraserUK

author: AndyC_772
author_rank: Super Contributor
timestamp: September 15, 2012, 07:35:28 am
content: Do be aware that materials like this are only suitable for packaging finished goods, not components or exposed PCBs. The reason is ESD.Components or exposed PCBs should be packaged in conductive or dissipative bags or foam (usually silver or black), and then packed in non-tribocharging material (foam or bubble wrap) which is usually pink.The conductive bag screens the board against electric fields, but not against magnetic fields. When an ESD event occurs, there's a very high dI/dt which results in a strong magnetic field around the discharge event, and that can in turn induce a current in a nearby conductor - even if that conductor is the opposite side of a conductive bag.That's why the pink foam is needed; it provides mechanical separation between the sensitive equipment and anything which could cause an ESD event. Pink foam is still an insulator, though, so although it doesn't generate unwanted static charge of its own, it offers no protection against charge that already exists. That's why the conductive or dissipative bag is also required.You would be AMAZED at the number of engineers and manufacturers who don't know or understand this - even those who do it for a living and who ought to be experts in this area. Many - including people who would never consider themselves advocates of bad engineering practice in any other area - are even publicly hostile to the idea of protecting equipment properly from ESD, and I've never understood why.

author: sotos
author_rank: Frequent Contributor
timestamp: September 15, 2012, 09:20:53 am
content: Thank you all very much for your time. You were very helpful.Sotiris.

author: sotos
author_rank: Frequent Contributor
timestamp: September 15, 2012, 09:26:57 am
content: Quote from: AndyC_772 on September 15, 2012, 07:35:28 amThey were very big electronic cards 40x40 cm, shipped from the manufacturer in this stuff.So I thought it’s the best for transporting PCBs and other.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: September 15, 2012, 10:54:32 am
content: Quote from: sotos on September 15, 2012, 09:26:57 amThe boards themselves are not ESD sensitive, but if they come packed like that, the boards could hold a charge and some effort should ideally be made to discharge the PCB before starting to mount components. For example laying the board flat on an ESD mat, on both its sides. Maybe I'm just paranoid, though.

author: amyk
author_rank: Super Contributor
timestamp: September 15, 2012, 11:17:36 am
content: A quick search shows thatthere is such a thing as conductive wool.

author: sotos
author_rank: Frequent Contributor
timestamp: September 15, 2012, 11:42:19 am
content: Quote from: amyk on September 15, 2012, 11:17:36 amIts not clear.It seems thas something black is inside of it.

author: sotos
author_rank: Frequent Contributor
timestamp: September 15, 2012, 11:46:17 am
content: Quote from: nitro2k01 on September 15, 2012, 10:54:32 amThe boards are populated they have MCUs, memories and other on them.