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I am in process of embedding a wire in a choice of substrates. I would apply voltage so much as to heat it (the wire) to 220 degree Celsius max. What are the best choice of substrates I can use so that if an element which has shock resistance of 180 degree Celsius will be efficiently heated and not crack down when kept on it?

Please assist me

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Electric oven elements are usually swaged metal tube over ceramic (mullite or alumina) beads strung on NiCr wire. The ceramic beads will crack, but once the metal tube is drawn tight over the cracked parts, the whole assembly remains intact through many temperature cycles.

The packed granules of temperature-stable ceramic are able to maintain spacing of the heating wire from the external tube. It isn't resistant to cracks, but remains functional despite them.

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  • \$\begingroup\$ how many times can i use the assembly you described (substrate layer of wire, ceramic bead and swag metal tube) to heat a material which has 180 degree Celsius shock resistance, making heat wire no more than 1.5 mm in length? considering what I described, do you suggest this link can be an appropriate fit? Can you please suggest a better in market substrate such as this? Thank you (alibaba.com/product-detail/…) \$\endgroup\$ – KSR Jan 31 '17 at 9:45
  • \$\begingroup\$ One can cycle the heat elements of an electric oven for years, with temperature excursions far above 220C. The link refers to an unknown PVC/silicone material; silicones can make formaldehyde at 250C. If the wire forms a hot spot, average temperature 220C could be destructive. \$\endgroup\$ – Whit3rd Jan 31 '17 at 9:59
  • \$\begingroup\$ I am trying to cut the need of ovens, I am trying cheaper fixes like externally heating up the material, allowing enough layers of substrates (dielectric and insulators) between heating wire and object to be heated, so as to prevent the material which will be heated from shock. have you come across any such assembly before? thank you \$\endgroup\$ – KSR Jan 31 '17 at 10:06
  • \$\begingroup\$ Heat tape and aluminum foil are commonly wrapped around items to make temporary ovens; see <today.slac.stanford.edu/feature/tin-foil.asp>. I'm unsure of what is inside the (ceramic or glass fiber jacket) heat tape. \$\endgroup\$ – Whit3rd Jan 31 '17 at 10:13
  • \$\begingroup\$ I am not able to access that link, i guess some sort of intranet. \$\endgroup\$ – KSR Jan 31 '17 at 10:17

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