Patent DE-102008040584-A1 (DE)
Title: Machine for coating a fluid or pasty coating medium on a surface of a moving material web such as paper or cardboard by curtain coating tool, comprises a curtain coating head, which is implemented with a discharge opening arrangement
Inventor: PLATZOEDER WERNER
IPC: B05C1/14
Filed: 2008-07-21
Abstract: The machine comprises a curtain coating head (110), which is implemented with a discharge opening arrangement (116a) connected or enclosable on a coating medium supply. The discharge opening arrangement brings a glide or draining-off surface (118) of the curtain coating head in the processing of the coating medium. The glide or draining-off surface is leaned and/or extends against the horizontals and ended in a tear-off edge (120) arranged against the discharge opening arrangement. The coating medium slides and/or discharges from the glide or draining-off surface. The machine comprises a curtain coating head (110), which is implemented with a discharge opening arrangement (116a) connected or enclosable on a coating medium supply. The discharge opening arrangement brings a glide or draining-off surface (118) of the curtain coating head in the processing of the coating medium. The glide or draining-off surface is leaned and/or extends against the horizontals and ended in a tear-off edge (120) arranged against the discharge opening arrangement. The coating medium slides and/or discharges from the glide or draining-off surface and is delivered from the tear-off edge in the form of a curtain movable itself under gravity force and the influx of the further force on the surface of material web (122) in a coating section of the progress of the material web. The progress of the material web diverts horizontally or corresponding to a radium of a reflecting and supporting rollers of the curtain coating tool or a rate of motion higher in horizontal direction than in the vertical direction. The curtain extends itself over a fall height between the tear-off edge and an impact line on the surface of the material web and a lower section of the curtain coating tool comprises a vertical distance from the material web surface and/or a horizontally running reference plane containing the impact line. The vertical distance has 80% of the fall height. The discharge opening arrangements are arranged along a glide- or tear off direction of the glide-or tear-off surface. The discharge opening arrangement brings the glide- or tear-off surface in the treatment of the coating medium. The discharge opening arrangements are connected to a characteristic coating medium supply in order to supply coating medium simultaneous to the glide or tear-off surface by the discharge opening arrangement. The fall height is 200 mm. An angle between a medium supply channel of the curtain coating head flowing in the discharge opening arrangement, and the glide- or tear-off surface or a tangential plane to curved glide- or tear-off surface on place of the discharge opening arrangement is greater than 90[deg] . The curtain coating head is modularly arranged from segments arranged to each other. Each discharge opening arrangement is assigned a defined segment. The segments comprising the tear-off edge comprises a slighter dimension in vertical direction than the segments of the curtain coating head. The dimension in vertical direction of the remaining segments of the curtain coating head is slighter than the dimension in the vertical direction of the opposite glide- or tear-off direction of the directly adjoining segments. The dimension in vertical direction of the curtain coating head in glide or tear-off direction decreases from segment to segment. A curved section of the glide or tear-off surface is 30% of the total surface of the glide- or tear-off surface between the tear-off edge and the discharge opening arrangement and/or the discharge opening arrangement stripped from the tear-off edge. The curved section of the glide or tear-off surface and/or the curved section of the glide or tear-off surface has a local curved radius of 30-50 mm. The curved section of the glide or tear-off surface extends in vertical direction over the height of 40-60 cm. The angle between the glide or tear-off surface or a tangential plane to the curved glide or tear-off surface and a horizontal plane on the place of the discharge opening arrangement is greater than 40-70[deg] . The planar section of the glide or tear-off surface between the tear-odd edge or a curved section guiding to the tear-off edge on the one side and a discharge opening arrangement on the other side and/or a planar section of the glide or tear-off surface between two directly adjoining discharge opening arrangement has a length in the glide and/or tear-off direction, where the length is greater than a thickness of the curtain coating head orthogonal to the planar section. The segments of the curtain coating head have a dimension in horizontal direction that is larger than a corresponding dimension in vertical direction of the segment. The curtain coating head is connected on a side external surface of the curtain coating head extending itself vertical to the tear-off edge on a coating medium source of the coating medium supply by a supply line. The curtain-coating head is connected on an external surface opposite to the glide- or tear-off surface in related to a breadth direction corresponding to the progress of the tear-odd edge by the area of the external surface of the curtain coating head by a supply line on a coating medium source of one of the coating medium supply. The supply line extends itself from the external surface of the height area of the curtain coating head with slight slop to a side area of the machine near to the material web. The internal medium supply channel of the curtain coating head is arranged in such a way that it cares for a uniform distribution of the coating medium to be supplied along the discharge opening arrangement.