Abstract:
Doctor blade dosing systems for devices used for coating material webs, particularly paper or paperboard webs, exist that have a doctor blade rod, which serves as a dosing element while being held inside a slot of a doctor blade bed that, in turn, is mounted in a support that can be fastened inside the frame of the system. According to the disclosure, the doctor blade rod has a diameter of less than 25 mm. The doctor blade bed is inserted in removable manner into a slot of the support situated on the face thereof. The ratio of the cross-sectional area (measured in mm2) of the doctor blade to the diameter (measured in mm) of the doctor blade rod is less than 60 mm, preferably less than 30 mm. The support is made of a plastic material and is shaped like a clamp having at least one rearward extending clamp limb and one joint location, whereby the holding slot that accommodates the doctor blade bed forms the clamp mouth. A tightening tube that presses the slot walls of the holding slot toward one another is placed on a clamp limb.
Abstract:
In the two-sided coating of a web by feeding the web through the nip of a pair of pressing rolls onto which the coating substance is metered, the amount of the coating substance applied to each pressing roll is measured by infrared absorption and the relative coating quantities RW.sub.o onto the upper side and RW.sub.u to the underside are calculated by the relationsRW.sub.o =M2.sub.o /(M2.sub.o +M2.sub.u) andRW.sub.u =M2.sub.u /(M2.sub.o +M2.sub.u); andwhere M2.sub.o represents an infrared absorption measurement of the coating on the roll applying the coating to the upper side and M2u represents the absorption measurement of the coating on the roll applying the substance to the underside of the web.
Abstract:
Coater for coating a material web, in particlular a paper web, guided along a backing roller, with a chamber for receiving the coating material, a doctor blade located where the web leaves the chamber, seen in the direction of travel of the material web, an adjustable overflow plate located at the front end of the chamber and with sealing members arranged in the edge region of the backing roller, covering the edges of the material web, comprising recesses extending in the direction of the web, edge scrapers extending in the direction of travel of the web from in front of the overflow plate to immediately in front of the doctor blade, with a channel and compressed air supply opening in the region of the overflow plate.
Abstract:
A device for adjusting a chuck to axially tension core tubes and consisting of a driven spindle and of a spindle nut that can be displaced by the spindle and is attached to the chuck. The object is to improve the chuck-adjusting device to the extent that the force involved in tensioning the core tube can be precisely prescribed. The chuck is accordingly connected to the spindle nut by a frictional connection that is subjected to pressure from a force generator and can be released from that pressure by the recoil exerted at the core tube during axial tensioning.
Abstract:
A slot nozzle for coating webs of material, for example, paper, paperboard, cardboard, with a flowable coating substance, for example, a pigment coating, has a slot shaped outlet channel to which a distribution chamber extending over the width of the web is connected. A plurality of supply conduits are connected to the distribution chamber in spaced relationship across the width of the web and the length of the outlet channel and each supply conduit has a valve for adjusting the volume flow of the coating liquid. A respective diffuser is provided between each supply conduit and the distribution chamber and widens in the direction of the latter.
Abstract:
In a web-coating apparatus a web moving continuously in a travel direction passes in a contact arc partially around a cylindrical surface of a backing roller centered on an axis. An applicator system has an applicator roller extending parallel to the backing roller, having a smooth cylindrical outer surface, and forming a gap with the backing roller. The web passes through the gap. A substantially stationary support extends generally parallel to the backing roll axis across a full width of the web and a pusher element limitedly movable generally radially toward and away from the backing-roller axis on the support bears radially of the backing-roller axis on the applicator roller along the full width of the web. An inflatable hose between the pusher element and the support along the full width of the web urges the element and applicator roller toward the backing roller. A coating liquid is supplied to the gap across the full width of the web.
Abstract:
A coater for a web of material, especially a web of paper or cardboard, that travels around a backing roll, with a doctor blade that presses against the backing roll and with components for adjusting the pressure that are distributed along the doctor and affect different areas along it. The adjusting components are piezotranslators (16).
Abstract:
In a device for coating a web of material that travels around a backing roller, the device having a coating chamber that opens toward the backing roller, that extends over the operating width, that has a slot demarcated at the web-intake end by an overflow plate for supplying liquid coating, and having a flow-control system at the downstream end, the improvement which comprises structures defining a coating-guide channelthat extends over the operating width at the outlet end of the coating chamber and terminates just upstream of the flow-control system,that is demarcated at one end by the backing roller and at the other by a baffle that essentially parallels the surface of the backing roller,that extends along the direction of travel at least 50% of the length of the overflow plate plus the flow-control system,that is open along its width perpendicular to the axis of the backing roller from 1.5 to 15% and preferably from 2.5 to 5% of its length, andthat terminates just upstream of the flow-control system.
Abstract:
Doctor blade dosing systems for devices used for coating material webs, particularly paper or paperboard webs, exist that have a doctor blade rod, which serves as a dosing element while being held inside a slot of a doctor blade bed that, in turn, is mounted in a support that can be fastened inside the frame of the system. According to the disclosure, the doctor blade rod has a diameter of less than 25 mm. The doctor blade bed is inserted in removable manner into a slot of the support situated on the face thereof. The ratio of the cross-sectional area (measured in mm2) of the doctor blade to the diameter (measured in mm) of the doctor blade rod is less than 60 mm, preferably less than 30 mm. The support is made of a plastic material and is shaped like a clamp having at least one rearward extending clamp limb and one joint location, whereby the holding slot that accommodates the doctor blade bed forms the clamp mouth. A tightening tube that presses the slot walls of the holding slot toward one another is placed on a clamp limb.
Abstract:
An apparatus for applying a coating liquid to a web moving continuously along a path has a main frame forming an open space and a main backing roller journaled on the main frame and around which the web passes. A second frame in the space is independent of the main frame and displaceable relative thereto from a position in the space juxtaposed with the backing roller. An applicator unit on the second frame applies an excess of the coating liquid to the web and a dosing unit downstream along the path from the applicator unit strips from the web excess coating liquid and leaves on the web a coating of the liquid of a predetermined thickness.