Dave Plowman (News) wrote:
Just as an update having seen some different makes, it appears some are
made out of copper clad Kapton, which is a thin flexible plastic sheet,
suitable for high temperatures, made by DuPont. The copper cladding is
etched into the element - rather like a PCB - and then laminated with a
second layer of plain Kapton. This sounds like it would be suitable for a
small production run - I know of several others who'd like replacement
elements. I've found a couple of suppliers of this stuff in the UK but not
had any replies to my e-mails.

Anyone have details of this process and suggestions for a supplier?

I've used these guys in a professional capacity:
http://www.minco.com/
They do a range of off-the-shelf heaters but also custom to you design
- size, resistance etc.

Basicly the process is as you describe. Etched resistive material (not
exaclty sure what) sandwiched between two layers of Kapton.

I found them helpful, flexible and relatively cheap. (I needed 10,000)
but my application was much smaller and higher precision than yours.

Regards,
Jon.