Curtain- or spray coating equipment for fibrous web used to make e.g. paper or card, runs web over one or more rollers with textured surfaces allowing escape of air boundary layer

摘要: Either or both of the rollers (5, 6) on either side curtain (4) coating nozzle (3a) in unit (3), is constructed as a known form spreading roller (50, 60). The 60) has structured surface with hardness between 20 and 90 measured by P&J plastometer. structure comprises depressions intervening strips, which offer volume for air escape. pattern repeated over each half length roller, opposed spiral configurations (i.e. chevron-like texture). An alternative roller(s) wavy strips grooves running axially along surface. This alternatively extends radially transversely respect to roller. In further variant, small cups, number studs grids, uniform distribution entire circumference.