Abstract: A screen plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.

Abstract: A screen plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.

Abstract: All of the essential operating parts for adding a top former assembly to a new Fourdrinier paper machine or for converting an existing Fourdrinier paper machine into a top former are carried by a supplemental frame assembly which can be mounted on the main Fourdrinier frame with minimal modification of the latter except the addition of simple parts for securing the supplemental frame assembly on top of the main frame. The primary operating parts of the top wire assembly are a hollow foraminous roll and a top wire deflector which cooperate to collect and deliver liquid expressed through the top wire into a receptacle that is carried by the supplemental frame assembly, and special provision is made for utilizing the top wire deflector to correct for irregularities in the cross machine profile of the paper sheet as it is being formed. Provision is also made for operating the resulting top former in roll former mode, blade former mode, or a combination roll and blade former modes.

Abstract: In screening apparatus for paper fiber stock of the type wherein a cylindrical perforate screen member defines screening and accepts chambers on the inner and outer sides thereof in a closed, pressurized housing, the inlet chamber for stock to be screened is located below the screening chamber to facilitate elimination of high specific gravity reject materials before the stock reaches the screening chamber. Special provision is made for accelerating the flow of plastic and other reject materials of lower specific gravity than wet paper fibers to a reject chamber above the screening chamber, and special provision is also made for preventing recirculation of such reject materials to the lower end of the screening chamber and thereby concentrating them in the reject chamber from which they are removed by way of a dewatering device that delivers essentially dry reject material for ready disposal while preventing the escape of pressure from the housing.

Abstract: A rider roll relieveing system includes a microprocessor for controlling the rider roll force applied to a roll of web material being wound which in turn controls the roll's density or hardness. The operator programs into the system the desired rider roll force or load at the start of the wind and a first diameter at which the rider roll relief is to begin. Also, the ending load at a second diameter at which relieving is to finish is programmed into the system. The microprocessor then provides for the progressive elief of the load as function of the roll's diameter, geometry, and weight between the two prestablished diameters to provide the desired hardness or the roll. The rider roll force is maintained constant until the web has been wound to the first diameter and after it has obtained the second diameter. The system digitally displays the winding roll's diameter and the rider roll force during the winding operation.

Abstract: A screen plate and plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.

Abstract: An apparatus for pulping paper making stock at high consistencies which includes a rotor body having a plurality of vanes extending generally radially outwardly therefrom and a feed screw mounted centrally of the rotor body and extending upwardly therefrom along an axis of rotation of the rotor body. The feed screw includes a conical body having a base with a periphery adjacent root portions of the rotor vanes and at least one helical flight extending along the length of the conical body and, in one embodiment, has a tapered end which is located adjacent a vane root. The rotor body and feed screw are mounted for rotation in a center portion of the bottom wall of a tub for holding paper making stock such that, when the rotor is rotated, the conical body and helical screw guide material contacting the feed screw downwardly and outwardly to contact the rotor vanes which impel the stock toward the side wall of the tub with sufficient force to climb the wall.

Abstract: All of the essential operating parts for converting an existing Fourdrinier paper machine into a top former are carried by a supplemental frame assembly which can be mounted on the main Fourdrinier frame with no modification of the latter except the addition of a pair of pivotal mountings and a pair of adjusting jacks for the supplemental frame assembly. The primary operating parts of the top wire assembly are a hollow foraminous roll and a top deflector which cooperate to collect and deliver liquid extruded through the top wire into a receptacle which is carried by the supplemental frame assembly. Provision is also made for operating the resulting top former in roll formation mode, blade formation mode, or a combination roll and blade formation mode.

Abstract: Apparatus for thickening a suspension of pulp material employs a single pair of liquid-impervious rolls and a single loop of wire trained around both rolls which are spaced from each other in substantially the same horizontal plane. The pulp stock to be thickened is delivered into the wedge zone defined by the upper wire run approaching the top of one roll and the surface of that roll, so that the pulp is trapped between the wire and roll as it travels around the roll with the wire, and the rolls are driven at sufficient speed to develop centrifugal forces which cause liquid to be expressed through the wire from the pulp trapped against the roll.

Abstract: In screening apparatus for paper making fiber incorporating a cylindrical screen member provided with cylindrical screening perforations, each of the perforations is characterized by a concentric frustoconical inlet end portion having a maximum diameter at the inlet surface of the screening member which is substantially greater than the portion of the perforation of minimum diameter, the maximum diameter of these inlet end portions being such that adjacent such portions closely approach or intersect each other to define multiple ridges on the surface of the inlet side of the screening member.

Abstract: Apparatus for the purpose of enabling a paper mill to determine the extent to which the performance and/or the product of an existing Fourdrinier paper machine in the mill will be improved by its conversion into a top former machine comprises a fractional version of top forming apparatus which can be readily combined with an existing Fourdrinier machine in such manner that a minor portion of the forming width of the machine will be converted to top forming operation. The apparatus makes it possible to produce, on an existing Fourdriner machine, a sheet of which a small integral portion is formed by drainage through both the primary wire and a top wire, while the remainder of the sheet continues to be produced in the same manner as before the top wire testing.

Abstract: In screening apparatus for paper making stock including a housing, a cylindrical perforated screen member separating the interior of the housing into a supply chamber and an accepts chamber on the inside and outside respectively of the screen member, an inlet port for supplying stock to one end of the supply chamber, an outlet port from the accepts chamber, a reject port from the supply chamber, and a rotor mounted for rotation within the screen member, the rotor is characterized by comprising a substantially circular disk which is of a thickness constituting a very minor fraction of the axial length of the screen member and has vanes mounted on its outer periphery which extend lengthwise of the screen member for rotation with the disk in the annular space between the periphery of the disk and the inner surface of the screen member.

Abstract: A cleaner for treating a liquid suspension of mixed relatively heavy and light particles to separate such particles from each other comprises parallel top and bottom plates, an outer wall, and an interior spiral wall cooperating with the outer wall to define a spiral passage having a plurality of turns and leading to an outlet port for heavy particles in the bottom plate. An inlet port delivers the suspension to the outer end of the spiral passage, and there is a second outlet port through one of the top and bottom plates for that portion of the suspension which includes the relatively light particles. Different arrangements of outlet ports are shown to provide for use of the cleaner for forward, reverse, through flow and three-way cleaning action.

Abstract: Paper and paperboard which have been thoroughly dried but not calendered is provided with a smooth surface by rewetting a thin layer (5% to 10% of the thickness) along the surface and then pressing the resulting damp surface against a substantial portion of the surface of a heated dryer drum or other smooth-surfaced cylinder. This technique provides the web with a surface comparable in smoothness with what can be obtained by calendering but without the degree of compaction which occurs in calendering, due to the fact that with the major portion of the web dried, it is highly resistant to such compaction. The same method steps can be applied subsequently to the reverse side of the web to provide it with two smooth surfaces. It is also possible to forego the rewetting step if the initial drying of the web is unsymmetrical so that one surface remains wetter than the remaining portion of the web.

Abstract: Apparatus for pulping paper making stock at high consistencies, e.g. 10 percent to 25 percent solids, includes a cylindrical tub and a rotor constructed and arranged to apply primarily pumping force to the stock which causes it to travel outwardly to and upwardly along the tub wall. This climbing stock is continuously subdivided and directed back into the tub, and a feed screw extending vertically upward from the rotor assures continuous circulation which develops zones of intense hydraulic sheer constituting the major force for effecting the desired defibering.

Abstract: A system for separating paper fibers from contaminants of similar lower specific gravities employs a reverse centrifugal cleaner wherein the discharge port for lights (reject) is located at the apex of the internally conical cleaner body and is formed by a tube which has it inner end located in the open apex end of the cleaner body and of smaller diameter to define with the end of the body an annular discharge outlet for heavies (accepts), the tube being releasably secured in position so that it can be temporarily retracted to relieve blockage of the heavies outlet.

Abstract: A system for the recovery of paper-making fiber from contaminated waste paper products including plastic film and other lightweight non-paper contaminants includes a novel rotary screening machine comprising a perforated drum rotatable about a generally horizontal axis and having openings at opposite ends for the delivery of liquid and paper furnished to the drum and the discharge of contaminants, respectively, a plurality of vanes for lifting material from the bottom of the drum to an upper region as the drum rotates, and a rotor mounted within the drum and having blades which are disposed in spaced relation to the drum vanes in a position to intercept material falling from the upper region of the drum and fling it back against the drum. The resulting fibers or flakes of useful paper are washed through the drum perforations while the rejected contaminants are conveyed to and removed via the discharge end of the drum.

Abstract: Pulping apparatus for pulping high consistency paper pulp includes a tub having a bottom wall and a generally cylindrical side wall extending upwardly therefrom, and a rotor mounted centrally of the bottom wall for rotation about a vertical axis and having a hub portion, a plurality of vanes extending generally radially outwardly from the hub and having pumping and defibering faces thereon, and a plurality of helical screw flights extending upwardly from the hub. Each flight has a concave undersurface such that rotation of the rotor in the presence of high consistency pulp causes the screw flights to draw pulp inwardly toward the axis of rotation and push it downwardly to the defibering faces of the vanes, and the outer surface of each flight being convexly curved and of substantially greater surface are than its undersurface to provide an air foil effect further tending to draw pulp into the path of the undersurface of the following flight.

Abstract: In a horizontal twin-wire paper machine, the paper sheet is initially formed in a wedge-shaped zone defined by generally horizontal runs of the primary wire and top wire which are brought into converging relation by cooperating sets of deflectors which support both runs against relative displacement by the stock therebetween and thereby cause liquid to be expressed through both of the wire runs throughout the wedge zone. The converged wires with the newly formed sheet therebetween then travel partially around one or more imperforate forming rolls, after which the top wire is guided away, and the sheet continues its travel on the primary wire. A major feature is the ease and simplicity with which the structure for supporting the top wire and the elements for defining the wedge zone can be added to an existing Fourdrinier machine to convert it to a twin-wire machine.

Abstract: A roll-type coater for applying a coating material to a web of paper includes an actuator mechanism for accurately controlling the movement and position of a metering roll with respect to a coating transfer roll, to prevent shock loading of the transfer roll upon closing movement of the metering roll, and to provide for rapid opening of the metering roll when necessary. The mechanism includes a bellcrank and link connected to move the metering roll along guideways, in which the linkage approaches, but does not exceed, an overcenter position just before the metering roll comes into contact with one or more micrometer blocks which space it accurately from the coating roll.