POLYMER MADE ELECTRIC HEATER MAKING METHOD Russian patent published in 1997 - IPC

FIELD: electrical engineering. SUBSTANCE: polymer made electric heater, for instance glass-fibre plastic one, making method includes electrical insulating backing forming and it impregnating with compaction by elemental carbon, graphite and modified phenolic formaldehyde resin to create resistive layer. External covering of resistive layer is making by epoxy, epoxy-phenol or phenol-formaldehyde binding impregnating. Then every layers are pressing at corresponding temperature, pressure and timing regimes, after they are gathering to stack with other resistive layers and treating by hardening process at temperature equal to 130-140 deg C during 10-12 min per one mm of stack thickness. After hardening processing each member is extracting out of stack for electric insulation covering layer-by-layer making with binding material using differently so that at electrically conducting layer surface it adding is 1,2-1,27 times less then at article external surface which is equal to 40-47 mass percent. EFFECT: less article reject yield of polymer made electrical heaters, higher availability and durability of operating. 3 tbc