What is this? Looks like Kapton material, not tape

Thread Starter

ThePanMan

Joined Mar 13, 2020
357
Sister bought a house. A very old house. Lots of mystery around a whole lot of hidden spaces. No bodies so far, but this was one of the things she showed me and asked if I had any idea what this might be. To me it has the look, feel and thickness of Kapton materials I've used over the years as an electronics assembler. This is a whole dang spool, 14 inches in width and the spool has approximately 3/4 inch of this stuff wrapped around a heavy cardboard spool. What do YOU think it is?
1637521104798.jpeg 1637521103731.png
 

Thread Starter

ThePanMan

Joined Mar 13, 2020
357
We've found some old motors, an old iron(ing) iron, an old soldering iron, the kind you put in the fire and heat it up, some brass oil fired miners headlamps (1 complete and in tact, 1 mostly complete and one reservoir). Found an old "Wonder Bread" bread board, probably belonged to Wonder Bread; no telling how old that thing is. But there's probably more treasures to be found.

Going to put a piece of this material into the vice and put a thermocouple behind it, then hit the face with a torch. Watch the temperature meter carefully and see if/how hot it gets on the other side. As far as pull testing - I don't have anything I could rig up for that.

One other question we have regarding the Kapton - is it worth something?
 

Thread Starter

ThePanMan

Joined Mar 13, 2020
357
Generally speaking, it's pretty tough. A square patch about 1 1/2" seems to have quite a resistance to pulling. However, it takes very little flame to melt the stuff. And once it starts melting it will burn. I don't know if Kapton will or won't burn. So I still don't know what I have.
 

SamR

Joined Mar 19, 2019
4,123
brass oil fired miners headlamps
The reservoir is for water on top and calcium carbide in the screw off bottom with maybe a spade lug on the back for helmet mounting. Acetylene generator lamps. Are they made by Justrite? Back in the 70's we used them for caving and the old ones were quite collectable by cavers. Now everyone uses electric.

The film maybe UV resistant for putting on windows?
 

Andrew Leigh

Joined Sep 8, 2008
131
Kapton is the Tradename used by Du Pont for Polyimide Film. The product was originally developed for NASA and the Apollo program. Developers then searched for alternate applications and it is now used extensively in railway traction motor coils.

The patent for Polyimide Film has expired and now anyone can make it. There are dozens of Polyimide Film manufacturers now. If your film is Polyimide then it is not Kapton but an equivalent. Kapton has a deeper colour tending more to deep orange / rust. Either way it is bloody expensive stuff.

Go peddle it to a d.c. armature winder, nice pocket money.
 

MrSalts

Joined Apr 2, 2020
1,545
Kapton is the Tradename used by Du Pont for Polyimide Film. The product was originally developed for NASA and the Apollo program. Developers then searched for alternate applications and it is now used extensively in railway traction motor coils.

The patent for Polyimide Film has expired and now anyone can make it. There are dozens of Polyimide Film manufacturers now. If your film is Polyimide then it is not Kapton but an equivalent. Kapton has a deeper colour tending more to deep orange / rust. Either way it is bloody expensive stuff.

Go peddle it to a d.c. armature winder, nice pocket money.
Color is proportional to film thickness. Kapton and other polyimide films are available in many thicknesses from <0.001" to >0.0.025". There is no way to diagnose the type of film from the color on a photo. At this point you are guessing.
 

Andrew Leigh

Joined Sep 8, 2008
131
Color is proportional to film thickness. Kapton and other polyimide films are available in many thicknesses from <0.001" to >0.0.025". There is no way to diagnose the type of film from the color on a photo. At this point you are guessing.
Not guessing at all. The company I ran was the South African distributor for both Kapton and Nomex. We were both consumers and resellers. I have handled more Kapton in all grades and thicknesses than I would care to remember, and yes depth of colour is proportional to thickness but not the hue. When the patents ran out on both products we saw a glut of the cheaper non Du Pont product flood the country and we needed to defend against these. The first one we came across was a generic called Apical made in the U.K. and since then many more. All grades of Apical were different in colour to Kapton. We made it our business to understand the differences in the products by sight in order to protect our markets.

I stand by my comment, generic forms of polyimide film tend to have more straw / brass colour hues than Kapton. They could never get close to the Kapton colour no matter how they tried.
 

Thread Starter

ThePanMan

Joined Mar 13, 2020
357
The film I have is 0.0043" thick. I will cut a piece and try with my temperature controlled soldering iron. Will report in about 15 minutes. Unless the wife stops me.
 

DickCappels

Joined Aug 21, 2008
8,686
Back in the 1970's is became apparent that the Kapton insulation used to wrap wiring harnesses in the F-15 aircraft was starting to break down, causing fires aboard the plane -not a happy discovery. A solution was quickly devised. Thermistors were wrapped along with the wires in the harnesses and if a thermistor sensed higher than normal temperatures, it activated a voice playback to alert the pilot. The voice recording started with "This is your Kapton speaking..."
 

Reloadron

Joined Jan 15, 2015
6,526
It looks to me like what we called Nomex developed by Dupont. It has a wide range of uses and we used it as an insulating material in motors we built. We used sheets exactly as pictured but also a honeycomb version. The stuff is used in dozens of applications including aerospace and even clothing.

Ron
 

Andrew Leigh

Joined Sep 8, 2008
131
It looks to me like what we called Nomex developed by Dupont. It has a wide range of uses and we used it as an insulating material in motors we built. We used sheets exactly as pictured but also a honeycomb version. The stuff is used in dozens of applications including aerospace and even clothing.

Ron
Nomex is a paper rather than a film and is a pale cream in colour, it is not transparent. It is made like any paper and is produced in calendered and non-calendered versions. Both Nomex and Kapton find widespread use in the electric motor industry with Nomex being more suited to a.c. applications and Kapton d.c. applications. Nomex fibres were used to make the fabric for racing driver suits and I think still are.

Both are amazing materials but neither like corona discharge. Their use in H.V. are limited to the corona inception voltage.
 

Reloadron

Joined Jan 15, 2015
6,526
Nomex is a paper rather than a film and is a pale cream in colour, it is not transparent. It is made like any paper and is produced in calendered and non-calendered versions. Both Nomex and Kapton find widespread use in the electric motor industry with Nomex being more suited to a.c. applications and Kapton d.c. applications. Nomex fibres were used to make the fabric for racing driver suits and I think still are.

Both are amazing materials but neither like corona discharge. Their use in H.V. are limited to the corona inception voltage.
Uh Oh, yes, thinking back it was a paper. Been retired too long and we used Nomex and yes, it was like a thick paper. My bad and thanks for pointing that out.

Other than Kapton Tape there is also just plain Kapton Film. That could be it. Going on 9 years into retirement and can't remember what I worked with. Getting pretty sad here. :)

Thanks
Ron
 
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