Method for perforating roofing sheet material

摘要

The apparatus of the present invention comprises at least one hole-punching device operated by a pneumatic cylinder for driving a punch rod through the peripheral surface and radially to the center of a roll of roofing sheet material. The method of the invention provides for the steps of preparing the sheet roofing material, winding the sheet into a roll, and punching a plurality of perforation holes in the roll from the surface to the center thereof.