Ribbon Cable

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:D Hi folks, Great Site!!!! So much knowledge and experience. Regarding PM content, is the wire in ribbon cables silver? I have found both silver and gold contacts on the end of the ribbon. Please advise. Thanks, Rick
 
Welcome to the forum Rick. I am not the one for that answer, but rest assured some will catch it for you. You just getting into this. Tell us a little about your adventures, so to speak. See you on the flip side.

Ralph
 
rickjackieb said:
:D Hi folks, Great Site!!!! So much knowledge and experience. Regarding PM content, is the wire in ribbon cables silver? I have found both silver and gold contacts on the end of the ribbon. Please advise. Thanks, Rick

Can anyone provide some insight on this?

Regards,

Rick
 
rickjackieb said:
rickjackieb said:
:D Hi folks, Great Site!!!! So much knowledge and experience. Regarding PM content, is the wire in ribbon cables silver? I have found both silver and gold contacts on the end of the ribbon. Please advise. Thanks, Rick

Can anyone provide some insight on this?

Regards,

Rick

My years of refining revolved around high grade wastes, so I don't now a great deal about electronic scrap, but it would be simple to test the ribbon in question. If the wire within is copper colored, pretty good bet that's what it is. If, by chance, you find it to be white in color, dissolve a tiny bit of it in a few drops of nitric acid and a touch of water----tap water will do. If you get a slight white precipitate in the solution as the wire dissolves, it's likely silver---and a touch of table salt will prove it is, or isn't. If it's silver, the salt will precipitate the silver nitrate as silver chloride, which will resemble cottage cheese to a degree.

If, on the other hand, your solution is blue, it's likely the wire is nothing more than copper, perhaps tinned.

Harold
 
Rickjackieb,

Welcome to the forum.

Sorry for the delays in answering this one. Harold's suggested test will provide you a definitive answer to your question.

I can assure you that silver paste is definitely used to print some of these ribbions. Another place you'll find silver printed circuits is inside keypad membranes. From microwave oven keypads to laptop keyboards, this silver printing process is a very common manufacturing process for membrane keypad circuits.

Here is proof of what Harold and myself are talking about:

This is an overview of a disassembled older laptop keyboard:

laptop_all.jpg



Here is a close up of the mylar sheets that contain the silver traces:
laptop_mylar.jpg



You will need to peel off the thin sticky backing on one side of the ribbon:

A shot of the nitric working on the silver traces:

laptop_nitric.jpg



And finally table salt has been added to produce the white silver chloride 'cottage cheese':

laptop_agcl.jpg



The fact that the silver is sandwiched between the mylar sheets makes recovering it an involved process. I would suggest controlled melting as an initial step to remove the protective mylar coatings. Mylar melts at 254C and silver melts at 961C.

I hope this helps.

Steve
 
All,

I spent one hour harvesting desktop keyboards for the mylar sheets. I processed 20 assorted keyboards in the hour. Of the 20 desktop keyboards 18 contained silver printed mylars. The total weight of the mylars was 9.8 oz. Here's a photo of the mylars:

mylars_9_8oz.jpg


I'll post more accurate silver yields when time permits.


Steve
 
Is anyone following this thread? :?

It's so quite you could hear a pin drop.

Anyway, I've slowly melted one mylar from a keyboard. The mylar and silver traces weighed 5 grams after gently melting with a heat gun set to medium. The mylar melted with no fumes and just crumpled into a semitransparent ball in the melting dish.

I then went at it with my Oxy/Act torch on the lowest possible gas flow and with the tip 6-8 inches from the mylar silver mass in the melting dish. After 30 minutes of tedious melting and periodic pouring off of black resins the silver began to group into a nice mash under the black goo. I tried to keep the mylar from igniting and producing a sooty smoke.

When no more melted resin would pour off, I added two teaspoons of borax and stepped up the heat; not full on but hotter and closer. Within five minutes the silver pooled into a BB while the borax flamed up as the last of the mylar residue burnt away in it.

Surprisingly the borax came out clear yellow when the last of the silver BB's joined together.

Here's a photo of the silver from the above process:

key_yield.jpg


I can't weigh the BB on my scales due to it's size , but I estimate it is no more than a quarter of a gram. If it is a quarter gram then a single pair of keyboard mylars should produce approximately 1/2 gram of silver per keyboard.

More to come later.

Steve
 
Well, if that don't beat all Steve! That't pretty cool. But you must of thought about the cost of supplies.
 
Phillip,

Absolutely. This was merely a test of the waters, a proof of concept if you will.

I have access to hundreds of free keyboards. If I can develop a large scale method to process pounds of these mylars in a single batch they may prove to be profitable. If nothing else they can provide very good silver for inquartations. :wink:

Steve
 
Is anyone following this thread?

It's so quite you could hear a pin drop.


I always follow your post steve. With great anticipation i might add.
But like a good cat i just lurke in the shadows. :shock:

I've been off following ( or trying to ) your latest video series.
I'm trying to learn the chemistry behind it. Dummy version of course.
Always looking for improvement, so to say.

You keep making them video's your going to need an agent one day. lol

I now know about keyboards thanks to you. :wink:

Ralph
 
aflacglobal said:
You keep making them video's your going to need an agent one day. lol

I now know about keyboards thanks to you. :wink:

Ralph

Don't know wether to love ya or to watch out for ya! LOL
 
Steve,

I just took apart about a dozen keyboards of different makes/model.

When I looked at the pair of mylar sheets that came of them all, the silver coloured traces are sat on the surface. I can get a sharp craft knife and scrape bits of them off.

Would this mean i could just pass the sheets through Nitric to dissolve the traces or would the Mylar interfere with this?

I'd have a go and see but i just don't like messing with Nitric!

Kind Regards
Buzz
 
Buzz,

You are right on the money. Passing the mylars thru a shallow pan of dilute nitric works. I tested a small piece a few months back. Like you said, I don't like working with nitric either, maybe there is an alternative solvent which will accomplish the same task.

I haven't done any more work on the subject as my silver supply is at a level that meets my inquartation needs for now.

Steve
 
Steve

Would boiling the mylars in just water separate the layers? If that were to work you could have access to the traces from above and maybe use a foam brush to spread the nitric over the traces, process and dispose of waste. Of course these are just thoughts so Im not sure if they would work.

dennis
 
Dennis,

The two mylars peel apart easily (they are only connected at a few points). The silver is printed on the mylar surface and is easily removed with dilute nitric. A scrub brush (toothbrush) would speed the process, but expose you to the acid more.

Steve
 
I've been following this thread, Steve. I've been lurking here for a long time now. I've stockpiled quite a few mylars. I am certainly interested in learning a cost effective way of processing these.

Fix
 
Welcome back,

I'm toying with using a dilute nitric bath dip tank for the mylars. I've tested it with a large clean pickle jar as the tank and my initial tests shows it works pretty well.

Steve
 
I did some quick math in my head and I will try to show my work here. You stated that one milar sheet could yield 1/2 gram, we will use that for our number. It takes 31.1034 grams to get one troy ounce. Quick math to me says you will need at least 63 keyboards to get one troy ounce of silver of todays value of $14.69. Thats a lot of work for what seems very little pay off because of materials needed to recover, almost break even on the deal.

I think this is possibly a project you take a bunch of keyboards into a second grade class with cheap #2 philips screwdrivers and have a group take them apart for you. The kids can use the contact rubber pads for projects, you get the milar steel and wire, and the school can dispose of the plastic (if non recyclable).
 
Evil said:
You stated that one milar sheet could yield 1/2 gram, ...


I said:
I can't weigh the BB on my scales due to it's size , but I estimate it is no more than a quarter of a gram. If it is a quarter gram then a single pair of keyboard mylars should produce approximately 1/2 gram of silver per keyboard.

Steve
 

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