De-watering drum for manufacture of paper, carton or tissue paper has regular array of de-watering holes with overlapping countersunk surface inlets

摘要

A paper-making assembly has a de-watering drum whose outer mantle is perforated by an array of drain holes (1) of diameter d1. The drain holes are countersunk in the surface zone. Some or all of the hole (1) overlaps with an adjacent countersunk depth (d1). Also claimed is a drum manufacturing process in which the grooves are formed by a stamp or die, followed by de-burring, sand blasting and coating with an anti-wear compound.