Method and apparatus for sharp color definition on the application of granules to roofing substrates

摘要

A high speed granule delivery system and method for dispensing granules in intermittent patterns onto a moving asphalt coated substrate includes a granule hopper and a rotationally indexable pocket wheel in the bottom of the hopper. A series of pockets are formed in the circumference of the wheel and separated by raised lands. A seal on the bottom of the hopper seals against the raised lands as the pockets are filled with granules during rotation of the pocket wheel through the hopper. As each pocket is indexed beyond the seal, it is exposed to the moving asphalt coated substrate below and its granules fall onto the substrate to be embedded in the hot tacky asphalt. The speed at which the wheel is indexed is coordinated with the speed of the asphalt coated substrate to form well defined patterns of granules at high production rates.

主权项

1. A method of creating adjacent patches of different colored granules on an asphalt coated substrate moving in a downstream direction in the manufacturing of shingles, the method comprising the steps of:
defining a series of spaced apart first areas along the asphalt coated substrate designated to receive granules of a first color and defining a series of spaced apart second areas adjacent to and between the first areas designated to receive granules of a second color; conveying the asphalt coated substrate along a production path in the downstream direction at a predetermined line speed; incrementally rotating a first pocket wheel to move a pocket of the first pocket wheel into a supply of granules of the first color; stopping rotation of the first pocket wheel to collect a partial charge of granules of the first color within the pocket of the first pocket wheel; incrementally rotating the first pocket wheel to move the pocket of the first pocket wheel across a stationary seal separating the supply of granules of the first color and the moving asphalt coated substrate to cast the partial charge of granules of the first color into the first areas to create granule patches having a sharp leading edge and an indistinct trailing edge, the partial charge being less than sufficient to cover the first areas and thereby leaving a portion of the first areas exposed; incrementally rotating a second pocket wheel to move a pocket of the second pocket wheel into a supply of granules of the second color; stopping rotation of the second pocket wheel to collect a full charge of granules of the second color within the pocket of the second pocket wheel; incrementally rotating the second pocket wheel to move the pocket of the second pocket wheel across a stationary seal separating the supply of granules of the second color and the moving asphalt coated substrate to cast the full charge of granules of the second color into the second areas to create granule patches having a sharp leading edge and an indistinct trailing edge, the full charge being more than sufficient to cover the second areas and thereby overlapping the leading edges of the patches of the first color; filling the exposed portions of the first areas with granules of the first color, and removing loose granules while retaining previously applied and underlying stuck granules to create adjacent granule patches of different colors with sharp linear color definition between patches.