A common method for the manufacture of asphalt shingles is the production of a continuous strip of asphalt shingle material followed by a shingle cutting operation which cuts the material into individual shingles.
In the production of the continuous strip of asphalt shingle material, a substrate such as an organic felt or a glass fiber mat is passed into contact with a coater containing liquid asphalt to form a tacky asphalt coated strip. Subsequently, the hot asphalt coated strip is passed beneath one or more granule applicators which apply the protective surface granules to portions of the asphalt coated strip to form a granule coated sheet. The granule coated sheet is cooled and subsequently cut into individual shingles.
In the manufacturing process, the asphalt coated strip is conceptually divided into an equal number of prime lanes, and headlap lanes. The prime lanes receive an application of prime granules while the headlap lanes receive an application of headlap granules. It would be advantageous if shingles could be manufactured with more efficient use of raw materials.