Abstract: The discharge pipes of a plurality of stock pumps, each supplying a separate concentrated stock slurry, are connected with a pipe containing comparatively dilute stock, commonly called "white water", discharged under pressure from a single fan pump on a single white water silo to supply separate slurries to separate chambers of a multi-ply web forming machine. The stock pumps have smaller capacities and pressure heads compared with a fan pump, thereby providing increased efficiency at required capacity with the minimum of equipment.

Abstract: A headbox for a papermaking machine or the like in which material, such as supension, flows from the headbox between upper and lower lips and through a discharge slot defined by the lips to a wire or a like receiver. The upper lip is reinforced by a beam extending along the upper lip on top of the lip while a detector is provided for detecting deflection of the upper lip due to the forces exerted thereon by material flowing between the lips. The detector is arranged to emit signals in conformity with deflection of the upper lip and correcting influences can be initiated in conformity with the emitted signals to compensate for the aforementioned deflection.

Abstract: The pressure at the breast box which is dependent on the dehydration capacity of the stock is measured and a measurement signal obtained which is used to regulate the paper machine. The pressure can be measured from the stock in the breast box, or where the pressure on the underside of the fleece on the suction roll is dependent on the pressure in the box, the pressure on the underside of the fleece can be used to obtain the measurement signal. Various components of the machine can be regulated by the obtained signal to produce a uniform paper.

Abstract: Undesirable high concentrations of fiber and moisture in the cross-direction profile of a paper stock slurry laid upon a papermachine fourdrinier screen may be selectively dispersed to level the cross-direction profile by impacting the screen carried pond of slurry at 1.5 to 4 feet down from the headbox slice opening with a fluid spray issued under a pressure drive of from 20 to 100 psi. If a cross-direction high concentration of fiber is to be corrected, the appropriate spray fluid to be used is water. If a cross-direction high concentration of water unaccompanied by a cross-directionally aligned high concentration of fiber is to be corrected, the appropriate spray fluid to be used is air.

Abstract: In a paper machine headbox system including a stock pump and a headbox receiving stock from the stock pump, the stock pump is shunted by a by-pass line. The stock flow to the headbox is primarily controlled by controlling the by-pass flow in the by-pass line by use of a by-pass flow control valve. When the by-pass flow control valve approaches one of its operating limits, i.e. either full open or full closed, the flow to the by-pass line is manipulated so as to reposition and maintain the by-pass flow control valve within its operating limits. A logic inhibit means, logically responsive to by-pass flow control signals, inhibits the stock flow rate in the main stock line.

Abstract: To achieve constant brightness from the chlorine stage of a wood pulp bleaching system, the chlorine addition rate is controlled by two white light photosensors positioned, respectively, 1-5 minutes downstream of the chlorine addition point and immediately prior to the chlorine washers. A relative error signal from the late photosensor is cascaded upon the set-point of a signal differentiator for the early photosensor to generate a chlorine valve control signal. The photosensors comprise selenium photocells positioned against a transparent stock conduit window and reflection illuminated by a low power white light source positioned more remotely from the window than the photocell at a discreet offset angle relative thereto. The white light is directed past the photocells, through the windows and into the flow stream; the photocells being responsive to the relative magnitude of white light reflected from the wood pulp. The power generated from the photocell is correlated to the pulp brightness.

Abstract: A simple and rapid test, and an apparatus for use therein, is described for measuring the filtration, or drainage, characteristics of a fibrous slurry. The results obtained by this test are accurately reproduced in production size systems, e.g. a wet process for the manufacture of asbestos-cement products such as sheet or pipe. The test utilizes a portable, light-weight leaf filter and can be run in 2-3 minutes.

Abstract: The vacuum pressure in the suction box which extends across the sheet-forming zone and terminates at the end of the zone is controlled in dependence on the pressure of the stock in the inlet duct opposite the suction box in order to maintain a constant column of stock liquid in the inlet duct at the end of the inlet duct. Various combinations of vacuum controlled suction boxes can be used.

Abstract: Specifically disclosed is the combination of a paper making machine and a control system including an automatic arrangement which, on demand of the machine operator, performs a coordinated machine speed increase, maintaining the paper sheet characteristics substantially constant until the dryer steam pressure or the steam valve opening reaches a limit. During the speed increase, a number of other machine variables are compared with set limit values and the speed increase is discontinued when a limit is exceeded for a predetermined time period. When the steam pressure has been at a limit, or the steam valve has been wide open, for a predetermined time period the control system, upon sensing the limit being reached, switches to a dryer limited mode of operation wherein the steam pressure is maintained at the limit or the steam valve is locked open.

Abstract: plastic coated sized paperboard, used in the manufacture of leak proof containers for liquids, is provided with a coating of a water-soluble calcium salt disposed between the sized paperboard and the plastic coating. In testing formed containers for defects in the plastic coating by means of a dye solution containing a wetting agent, the coated paperboard of this invention provides for a more positive determination of the nature and size of any defect indicated than heretofore since the calcium ion present in the coating imparts good resistance to excessive penetration and spreading of the dye solution.