Process for the manufacture of asphalt shingles

摘要

A rectangular shingle sheet having a butt portion which is longitudinally divided into spaced apart tab segments and an undivided headlap portion which is 1.3 to 1.5 times higher than the outward extensions of said tab segments in the butt portion; the butt portion and headlap portion carrying an asphaltic backing of varying thickness wherein the upper area of the headlap portion which is of a height approximately equal to that of the butt portion is coated with an asphaltic backing of between about 5 and about 15 mils thickness and the remaining lower area of the headlap portion and the entire butt portion is uniformly coated with an asphaltic backing of between about 20 and about 100 mils thickness. In one embodiment, the shingle is a composite roofing shingle comprising a shingle sheet having a butt portion which is longitudinally divided into spaced apart tab segments, and a separate elongated strip underlying the tab segments which fills the space between the tabs. A process for the manufacture of the shingles of this invention. comprises undercoating the butt portion and from about 1/7th to about 3/7ths of the adjoining headlap portion with an asphaltic material in a thickness of from about 20 to about 100 mils, undercoating the remaining headlap portion with asphaltic material in a thickness of from about 5 to about 15 mils and contacting said thicker undercoating with a bar which hydroplanes on the surface of the thicker undercoating to smooth the surface thereof.