| 摘要 |
A method of making roofing shingles in several lanes in which, after the asphalt saturated base sheet is covered with a first granule layer, a pattern of asphalt patches is printed on each lane and contrasting color granules are adhered to the patches. Each patch pattern repeats each shingle length but is non-symmetric about the center line of the length of each shingle. When the sheet is cut into shingles, the shingles from each lane have a different patch pattern from the other lanes. The shingles are assembled in bundles containing shingles from at least two lanes and approximately equal numbers of the patch patterns are located on opposite sides of the bundle to make sure the bundle is not tilted. The patch pattern is such that when each shingle is cut into tabs (thirds), at least one and preferably two tabs from each shingle has its center free of patches, enabling the tab to bend over a ridge with less risk of cracking. Preferably no patches are located at the lines where the shingles are cut into tabs. |
