| 摘要 |
An electric heater unit is manufactured so as to form a base (8) in a supporting dish (4) by compacting powdered microporous insulation into the base. At least one electrical resistance heating element (12) is supported on or adjacent to the base and a peripheral wall (11) is formed in the supporting dish and integral with the base by compacting further microporous insulation material into the dish to a controlled compaction density. The compaction density of the peripheral wall (11) may be different from that of the base, for example higher. <IMAGE> |
