Abstract: Method and apparatus for applying a secondary layer or coating on surfaces of wet formed board materials are disclosed. The secondary layer is applied to the wet mat material of the board being manufactured during press rolling of the wet mat. The secondary layer material is supplied in the form of a slurry which is caused to adhere to the surface of a wire screen. The wire screen surface bearing the layer of slurry material is then pressed onto the mat surface to deposit the slurry layer thereon.

Abstract: Apparatus for forming one or more sheets from a dilute suspension of fibers in a liquid has a Fourdrinier wire the upper reach of which travels above a foraminous support, and a head box which has an outlet discharging the suspension onto the upstream portion of the upper reach. The liquid passes through the wire and support, and the fibers form a mat which is carried and advanced by the upper reach of the wire. The apparatus has several deckles which are impervious to liquid and are mounted in or on the support or at a level immediately above the upper reach of the wire. Each deckle extends lengthwise of the entire outlet of the head box and its width is only a small fraction of the width of the outlet. Feed screws or the like are used for moving the deckles sideways so that they overlie selected elongated zones of the upstream portion of the upper reach of the wire, and each deckle can be releasably fixed in the selected position.

Abstract: The invention relates to a method and a device for separating liquids and solids from a mixture, in which the mixture is applied in the form of a layer to a movable, endless filter belt, which is supported from a subjacent suction box adapted to move parallel to the belt, in which box a subatmospheric pressure is intermittently produced, the liquid constituents of the mixture being drawn across the filter belt during the periods of subatmospheric pressure, while the filter belt and the suction box are in intimate contact with each other and do not move relatively to each other owing to the suction force, whereas at the restoration of the atmospheric pressure in the suction box a relative displacement of the filter belt and the suction box is carried out.

Abstract: A papermaking machine of the Fourdrinier type having a machine wire which passes about a breast roll adjacent a head box and which passes around a further curved guide member spaced from the breast roll and about which guide member there is also entrained a belt in the form of a felt or additional wire. Beneath the machine wire between the breast roll and the curved guide member is a suction region which is characterized in that it is free of any wire supports or the like which would create pressure impulses in the suspension on the wire, which pressure impulses would interfere with the formation of the paper sheet.