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Old 3rd January 2010, 02:19 AM   #241
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Quote:
Originally Posted by bear View Post
I wonder if we could identify what exactly this "nylon 6.6" is?
I'm unfamilliar with it...
[-OC-( CH2)4-CO-NH-(CH2)6-NH-] n
Nylon 6,6 is made of hexamethylene diamine and adipic acid, which give nylon 6,6 a total of 12 carbon atoms, and its name.

To Calvin:
Exact Quad techology has not been disclosed yet - so it is just idle talk.
Quad coating is quite grayish which means it does contain carbon one way or another.
Elvamide dealimination is impressively proved by quad as well - otherwise there will not be that many repair kits on avail, including few provided by DIYaudio community.

DIYaudio has been offered another solution.
It did create lovely discussion mostly because it is fully disclosed like TESA glue one.
Let's treat it the same way by repeating it, instead of looking for the reasons why it CAN NOT BE DONE.
Alex
P.S. If it would of been a simple dehydration - than the coating would of turn opaque reasonably fast.
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Old 3rd January 2010, 09:17 AM   #242
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Hi,

if claims are made that sound doubtfully You should accept that the claims are put to test.
For the procedure shown and the following discussion these claims were made (as far as I understood)
claim1: a diaphragm made of a plastic film like PET is coated with a layer of carbon to achive a certain conductivity. A second layer made from PA6.6 is brought onto the membrane film and said 1st layer to protect the conductive layer from environmental influence.
claim2: The PA6.6 layer heated till it melts. As such the layers are ´welded´ together forming a single conductive compound thats layers don´t delaminate
claim3: the process leads to a film compound with desirable electrical properties
claim4: the process leads to a film compound which is unaffected by environmental stress

claim1: Polyamides prooved to have desirable electrical conductivity for usage as ESL diaphragm coating, apart from a strong relation of resistance values to moisture. The conductivity of PA renders a first conductive layer of carbon obsolete. Especially since a good uniformity of conductivity is very difficult to achieve with carbon layers. If one wishes to remain with carbon as concutive layer a different set of parameters for a protective coating would be desirable, as for example reduced moisture sensitivity, hydrophobicity, increased dielectric strength, higher flammabilty resistance et al.
claim2: The heat treatment is applied to an array of layers of which the base layer is tightly stretched. PET has a specified melting point of 254°C to 260°C, pure PA6.6 one of 260°C. Glass-transition points are similar too at ~60°C-70°C. So immediately before(!) PA6.6 melts the PET film melts too, thereby loosing all its mechanical tension and beeing destroyed.
claim3: Even if it were possible to form a compound film with this technique the uniformity of conductivity would still be no better than that of the original carbon layer and the surface of the ´protective´ PA-layer would still be hyproscopic and moisture sensitive.
claim4: citing from a PA6.6 (or PA66) manufacturere´s Website:
Quote:
Polyamide is hygroscopic and moisture sensitive, so pre-drying is recommended as a matter of rule. Material that is not pre-dried to a moisture level below 0.1% will degrade, causing surface defects, parts that are out of dimension and brittle parts.
The volume resistance diagram shows a decrease in the order of 6 exponents over a range from 10e15 down to 10e9 over a range of 0.1% to 8% of moisture content. The tendency to absorb water is increased when fibres or dopings are added.

So all in all I strongly doubt that the claims describe what is really happening here and that the result of the process is as claimed.
Instead I assume that the heating reverses the gelling process (cloudy, milky appearance). The solving agent alcohol evaporates and the coating is stabilized (no new gelation, hence it stays transparent)

jauu
Calvin
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Old 3rd January 2010, 09:32 AM   #243
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Quote:
Originally Posted by alexberg View Post
Elvamide dealimination is impressively proved by quad as well - otherwise there will not be that many repair kits on avail, including few provided by DIYaudio community.
The fact that repairs are needed does not prove that the coating delaminates. Do you have any other reason to believe that this is the case?


@Calvin
nice post!
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Old 3rd January 2010, 12:16 PM   #244
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Quote:
Originally Posted by arend-jan View Post
The fact that repairs are needed does not prove that the coating delaminates. Do you have any other reason to believe that this is the case?


@Calvin
nice post!
To Calvin: Nice explanation, but have you tried? We are still going towards applied chemistry scholastic discussion.

Quads were in production for quite a while - so we can have some statistics - and could derive some suggestions.
One needs multiple Quad sets in posession to analyze. Delamination is an impression I have got from the internet, unfortunately...

It seems that Calaton/Elvamide recipies have to have a lot of know-how: ethanol soluble nylon coating does not have any adhesion to PET film.
It forms something looking as a thin layer of dust, easily removable

My contibution in "MELT MATTER" was a mere translation...
Again I failed to reproduce what has been described: film has melted but the coating behaved the way it has been shown in clip. I tried an alcohol used in yarn production as solvent... not ethanol, for sure.
It seems though, if phenol was present melting point would be lower...

On the other hand, the biggest challenge is to make a permanent coating - this thread is a proof.
And it's quite possible no such thing exists due to dissimilarity of the substrate and overcoat subjected to uncoutable number of bends not
saying about the environment.
Plazma deposited or otherwise embedded into a membrane conductive material is probably the best known solution - Martin Logan claims so.

BTW Could anybody tell me whether or not TESA glue is water soluble after drying?
Sincerely,
Alex
P.S. At least nobody speaks about "triboelectric" self-charging... or putting some futty acids as a primer...
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Old 3rd January 2010, 04:30 PM   #245
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Even Martin Logan have had some problems with their plasma sputtered coatings.....but I remember that Aucostat bragged about their indestructible panels, not one were changed of 18000 built!
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Old 3rd January 2010, 04:46 PM   #246
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alexberg
Thanks for supporting my method of coating.
Calvin
Heat treatment changing stretch film (PET) really, but the whole point is that processing of the membrane-coated nylon is advance before installing the ESL. Stretch of the membrane is another topic for conversation.
claim2: The heat treatment is applied to an array of layers of which the base layer is tightly stretched. PET has a specified melting point of 254°C to 260°C, pure PA6.6 one of 260°C. Glass-transition points are similar too at ~60°C-70°C. So immediately before(!) PA6.6 melts the PET film melts too, thereby loosing all its mechanical tension and beeing destroyed.
But you have to notice the fact that the nylon coating is much thinner than the membrane of mylar, and if you look closely watched videos that could be seen in the slow movement of the Hot air gun over the surface of the diaphragm and hence the upper layer warms up more strongly than the lower..

So all in all I strongly doubt that the claims describe what is really happening here and that the result of the process is as claimed.
Instead I assume that the heating reverses the gelling process (cloudy, milky appearance). The solving agent alcohol evaporates and the coating is stabilized (no new gelation, hence it stays transparent)


The fact that the coating nylon only after pre-drying may be subject to thermal treatment.

Last edited by Statics man; 3rd January 2010 at 05:04 PM.
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Old 3rd January 2010, 05:29 PM   #247
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Calvin
claim3: Even if it were possible to form a compound film with this technique the uniformity of conductivity would still be no better than that of the original carbon layer and the surface of the ´protective´ PA-layer would still be hyproscopic and moisture sensitive.
The volume resistance diagram shows a decrease in the order of 6 exponents over a range from 10e15 down to 10e9 over a range of 0.1% to 8% of moisture content.

But the resistance of the coating and should not be less than 10e9 ohms.
In other words, nylon 6.6 has all the qualities necessary to cover the membrane

Last edited by Statics man; 3rd January 2010 at 05:33 PM.
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Old 3rd January 2010, 05:48 PM   #248
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Statics man, I would like to try your method, can you make a list of what is needed?

I have mylar, 6 and 12 uM, I also have a heat gun with adjustable heat.
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Old 3rd January 2010, 06:13 PM   #249
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JonasKarud

I would like to try your method, can you make a list of what is needed?

I have mylar, 6 and 12 uM, I also have a heat gun with adjustable heat.



This is a very labor-intensive process requires great precision in the work on this, the video shows one of the stages of this process. If you're ready. Contact me by mail.

P.S. In general, my method is available here : http://www.audioportal.su/showthread.php?t=11841&page=3

Last edited by Statics man; 3rd January 2010 at 06:27 PM.
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Old 3rd January 2010, 06:35 PM   #250
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Quote:
Originally Posted by alexberg View Post
Quads were in production for quite a while - so we can have some statistics - and could derive some suggestions.
One needs multiple Quad sets in posession to analyze. Delamination is an impression I have got from the internet, unfortunately...
I have seen hundreds of Quad panels (I refurbish them) and have never seen anything that looked like the coating coming off. I know this is what people write, the only thing I can say is that there is a lot of stuff out there on the web which just ain't true. Some panels do look like they were only partially coated in a sloppy way, and this is probably the case
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