plastic as conductive material?

[originator]

I am designing a product that uses laminated glass with a yet unknown product between the glass that can simulate a netal surface. I am using touch circuitry, and the material needs to act like metal in the sense that metal works great for touch pads. 1/4" glass over the metal works fine as well, however for cutting and glueing I prefer a mylar type substance that is easier to work with.

Is there a plastic product that will act like metal in the sense desribed above? Ideally, I'd like to attach a bolt through the two sides of glass and come in contact with the plastic laminate, creating the conditions for touch circuitry to perform. The thought of a conductive paint may work as well if such exists. I am not versed in plastics or related conductive products, any tips would be great for a plastic conductive product 4'x8' x 1/16" in size. Thanks

 

[patprimmer]

Conductive is a relative term. It depends on what you call conductive.

Stainless steel fibres will make many plastics conductive.

Regards

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[dans95]

We use a conductive paint on plastic parts to provide EMI shielding. Electrodag EMI paint from Acheson Colloids Co.

We also use a carbon filled polypropylene in a capacitive contact sensing system. I don't know the specifics of the materials but seems that something like that could work for your application.

 

[ornerynorsk]

Carbon fiber?

 

[patprimmer]

High surface area carbon black, special grades of carbon fibre and stainless steel fibre as well as special conductive polymeric additives and even simple surfactants like quaternary ammonium compounds can impart various levels of conductivity with various levels of permanence and various levels of influence on other properties.

Does this application require transparency. Carbon black kinda ruins that if that is the case.

Quats are not very effective nor consistent nor permanent, so I guess their out.

SS fibre in polycarbonate could do it as it can be translucent if that is advantageous.

SS fibre gives the highest conductivity, but it still falls well short of metals re conductivity. It is very very expensive.


Regards

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[ozchevy]

I'm interested in a coating to be applied by spraying onto the surface of ABS that is conductive, so it can then be Chrome plated. If any of you guys know of such a product please post it on here. The EMI Paint sounds ideal, but I cannot find that product here in Australia, so much for Google.

 

[patprimmer]

ABS can be plated.

The plater can treat it in a bath that deposits nickle on the surface, they build from there.

For reliable good results, the part should be new, clean, unstressed and platable grade ABS.

There are several companies in Australia that do it. At least one in Sydney and at least one in Melbourne.

Regards

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[originator]

Thanks guys for the info!

Todd

 

[patprimmer]

ozchevy

I just saw you are in Sydney.

Try Vulkan Plastics in Garnet Street Rockdale.

Are you at Revesby or StMarys

Regards

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Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[ozchevy]

Hi patprimmer,

Yes I am very close to St Marys, I work in that suburb so know it well. Is there a plater in St Marys that can plate ABS? Just looked in the phone book and online, didn't come up with anything, although I do see Vulkan Plastics listed.

Regards

 

[dans95]

ozchevy wrote: "The EMI Paint sounds ideal, but I cannot find that product here in Australia, so much for Google."

Try

http://www.achesoncolloids.com

We buy it from our local Sherwin Williams dealer.