Abstract: Method and apparatus for applying a liquid film of controlled thickness to a paper web. The apparatus is in the form of a flexible blade coater having a flexible blade fixed at one end and bearing against a backing roll (with interposed web) at a free end. The blade has independent loading means, preferably pneumatic. An intermediate loading means applies a first load intermediate the fixed and free ends which serves primarily and substantially independently to establish blade geometry or tip slope. A second loading means positioned near the free end of the blade primarily and substantially independently establishes tip load for a given geometry established by the first loading means. The compound loading arrangement allows a wider range of finer control of coating film thickness.

Abstract: A coater and a method of operating such coater is disclosed. The method of operating the coater includes the steps of separating a first tail from a full width web unwound from an unwind stand at threading velocity and threading the first tail at the threading velocity through a pull stack. The first tail is widened to the full width of the web so that a full width web extends through the pull stack. The full width web emerging from the pull stack is dumped into a first broke chute which is disposed below the pull stack. The full width web extending through the pull stack is accelerated along with a coating apparatus to coating velocity so that both the full width web and the coating apparatus attain coating velocity. A second tail is cut in the full width web between the unwind stand and the pull stack and such second tail is threaded through the coating apparatus while the second tail is moving at coating velocity.

Abstract: An apparatus for the application of a sizing composition or the like to a traveling web under high speed conditions which involves passing the web into the nip formed between two counter-rotating rolls and supplying a sizing composition to the nip to thereby form a pond of sizing material on both sides of the traveling web. Additional amounts of sizing material are constantly being supplied to the ponds by means of a suitable applicator and nozzle arrangement, while the depth of the ponds is controlled continuously by the application of a reduced pressure to the existing ponds resulting in some of the sizing composition being drawn up into the applicator from where it is delivered to a reservoir for further circulation through the applicator.

Abstract: A fountain type web coating applicator and method wherein flow of coating material from source to a doctor blade coating nip with the continuously travelling web is subjected to a plurality of successive pressure drops so that coating material reaches the coating nip uniformly throughout the extent of the doctor blade edge. One of the pressure drops is through a multi-port pressure drop device and another pressure drop is through a slit orifice pressure drop device. A novel arrangement for easy replacement clamping of the doctor blade is provided. A doctor blade thruster is adjustable up and down along the blade relative to the upper coating nip edge of the blade.

Abstract: An end dam sealing means for at least one end of a coating application chamber defined in part by a doctor blade and backing surface means such as a roll on which a web to be coated travels continuously, is adapted for engaging sealingly with a chamber surface area, the doctor blade and the backing surface means roll, and the sealing means has a device for draining coating material that may migrate from the application chamber between the sealing means and the backing surface means roll. Static seal is provided for the contiguous end of a pressure drop chamber and a slit orifice which communicate with the coating application chamber.

Abstract: Pond pressure controlling device, e.g. a tiltably mounted metering lip baffle is mounted on the floor area which in part defines with an upstanding doctor blade and rib running on the backing surface roll a coating application pond chamber, provides an adjustable output orifice for the chamber spaced from the blade at an upstream location relative to the direction of travel of the web. A pressure fluid responsive device, e.g. an inflatable bladder, is adapted for selectively adjusting the pond pressure controlling lip baffle for obtaining a desired output orifice dimension. In another form the controlling device may comprise simply an inflatable tubular bladder mounted on the floor area provided with any adjustable orifice-defining rib.

Abstract: A method for the application of a sizing composition or the like to a traveling web under high speed conditions which involves passing the web into the nip formed between two counter-rotating rolls and supplying a sizing composition to the nip to thereby form a pond of sizing material on both sides of the traveling web. Additional amounts of sizing material are constantly being supplied to the ponds by means of a suitable applicator and nozzle arrangement, while the depth of the ponds is controlled continuously by the application of a reduced pressure to the existing ponds resulting in some of the sizing composition being drawn up into the applicator from where it is delivered to a reservoir for further circulation through the applicator.

Abstract: A coater for applying a coating material to both sides of a traveling web with the web passed over a back-up roll and a first coating such as sizing applied to the back-up roll surface in advance of a coating zone for transfer to the web at the coating zone and the second surface of the web being coated by a trailing blade coater applying pressure to the web urging it against the back-up roll.

Abstract: A holder for rotatably mounting the metering rod in a rod-type web coating apparatus, such as used to coat paper, is made of a rigid but yieldably deformable material, such as a plastic. The holder includes a plurality of longitudinally extending conduits for carrying water to lubricate the rotating rod and removing coating particles which are carried by the rod from the web surface and into the rod cavity. The holder has a surface opposite the rod cavity for receiving a uniformly applied load along the longitudinal length of the rod holder for aligning the rod surface and/or applying a uniform nipping load between the rod and surface of the web being coated. A second surface also extends longitudinally for the length of the holder along a lip portion which protrudes from one side of the cylindrical rod cavity.

Abstract: A traveling web coater for applying a smooth uniform layer of liquid coating of controlled weight onto the surface of a traveling web including a gate coater having a plurality of gate rolls for metering and applying coating to a traveling web supported on a backing roll with an air knife positioned to direct air onto the web downstream from the gate rolls and to essentially smooth the coating removing a minimum amount of the coating which has been accurately metered by the gate rolls.

Abstract: A rotary hollow shell cylindrical heat transfer roll for either chilling or heating a web has a device therein for controlling a heat transfer liquid to flow as a uniform thin layer stream in heat transfer relation to the inner cylindrical surface of the roll substantially throughout the width and limited to substantially the circumferential length of the area of the outer periphery of the roll over which the web travels. The direction of flow of the heat transfer stream is opposite to the direction of rotation of the roll.