Vacuum-formed electrical heating device and method of production

Abstract From the Canadian patent

In a vacuum-moulding process for manufacturing an electrical heating unit, in which process a resistance heating coil is placed on a sieve-like tray, above a suction box, and a slip is applied thereto this slip being, composed of ceramic fibres so that a ceramic fibre layer builds up under the action of suction, it is proposed, according to the invention that portions, of the sieve-tray be closed in regions beneath the resistance heating coil in particular by means of spacing strips and that these strips, which cover, some of the perforations in the sieve-tray be placed beneath the resistance-, heating coil but in a manner such that the impervious regions of the sievetray are narrower than …