Patent ID: 6228422
Filing Date: 2001-05-08
Classification: B05C,E04D

Abstract:
A method for manufacturing an asphalt roofing material, comprising:coating a continuous base mat with liquid asphalt to form a tacky asphalt-coated sheet; anddischarging granules from a series of granule applicators onto the asphalt-coated sheet to form a granule-coated asphalt sheet, at least one of the granule applicators discharging blend drops of granules onto the asphalt-coated sheet, the discharging of a blend drop comprising:discharging granules through a discharge slot of a granule feed chamber onto the asphalt-coated sheet, and controlling the discharge of a blend drop of granules by moving a slidegate with an actuator between an open position in which the slidegate opens the discharge slot so that granules are discharged through the discharge slot, and a closed position in which the slidegate closes the discharge slot so that granules are not discharged through the discharge slot, wherein the actuator moves the slidegate between the open position and the closed position with sufficient quickness to produce a blend drop on the asphalt-coated sheet having a uniform distribution of granules.