Net shape holders, insulators, hangers and supports in alumina, mullite and cordierite, cast to close tolerances.
Elements fail where they touch their supports.
The holder decides how evenly they hang and how long they last.
Heating elements at high temperature are supported by ceramic holders that insulate electrically, resist thermal shock and keep their shape under load: typically alumina, mullite or cordierite. Blasch casts element holders, insulators, hangers and structural supports in these materials as net shape parts with close tolerances, so every holder in a furnace is the same and the elements sit where the design puts them. Shapes are made to the furnace design, from small insulators to complete support structures.
An element holder carries a wire, ribbon or rod element inside a furnace wall or roof. It has to hold the element in position at full temperature, insulate it from the furnace structure, and survive every heat up and cool down without cracking.
When holders vary in size, elements sag, touch each other or the wall, and develop hot spots. When a holder cracks, the element drops. Both shorten element life and make the temperature in the furnace less even.
A furnace heats as evenly as its elements hang, and the elements hang as evenly as their holders are alike, which is why tolerance matters as much as temperature.
| Material | Where it fits |
|---|---|
| Alumina | Highest temperatures, electrical insulation |
| Mullite | High temperature with frequent thermal cycling |
| Cordierite | Low thermal expansion where thermal shock dominates |
Cordierite for thermal shock and mullite as a furnace ceramic are described in detail on their material pages.
The Blasch process casts ceramic close to final shape, with a linear tolerance of about ±0.005 in per inch (0.5%), repeatable from part to part. Grooves, slots, holes and threads for the element are cast in, so holders need no machining and fit the same way in every position.
Besides element holders, the same process makes structural supports, induction furnace tubes, hangers, bricks and other furnace parts. How the Blasch casting process works
Element holders are part of the non-ferrous and aluminum group.
Setters, plates and muffle liners for the parts that travel through the furnace.
Ceramic tubes that hold the element inside a metal bath instead of the furnace wall.
Yes. Holders are cast to the furnace design. Dimensions or a sample of the current holder are enough to start.
Where thermal shock is the main load, cordierite and mullite are the usual choices. Where temperature and insulation matter most, alumina.
No. Blasch makes the ceramic holders, insulators and supports around the elements.
Send the furnace design, the element type and the temperature. A Blasch engineer proposes holder shape and material.
