| abstract |
The disclosure relates to a method for producing hollow cylindrical structures, and more particularly for producing hollow cylindrical structures which may serve as collector electrodes for electrostatic precipitators; the method comprising the forming of a first resin and fiberous structural layer on a rotating mandrel, then applying a foam structure forming resin on the first structural layer, then permitting the foam structure to cure into a structural condition, then lathe turning the periphery of the foam structure to a uniform annular cylindrical surface, then applying a second layer of resin and fiberous material to form an external structural layer and then finishing the exterior of the last mentioned structural layer to a uniform annular shaped surface, and finally coating the last mentioned surface with a water resistent resinous material and then removing the glossy surface from said last mentioned material to prevent surface tension of water from separating flow on said last mentioned surface; the disclosure also relating to detailed instruction of the aforementioned fiberous structural layers. |