FIELD: producing loose materials. SUBSTANCE: openings are arranged in rows in the direction of movement of a belt. The openings in each subsequent row are shifted with respect to each other so that the area overlapped by perforation holes is constant independently of the trajectory of the perforation holes. EFFECT: enhanced efficiency. 7 cl, 5 dwg
Authors
Dates
1997-12-27—Published
1995-05-26—Filed