Abstract: The manufacture of sag-resistant, lightweight structural mineral panels on a foraminous support wire is accomplished by forming a dilute aqueous dispersion of mineral fiber and/or aggregate and an anionically stabilized latex binder, coupling the binder solids onto the mineral fiber materials by adding a small amount of a flocculant such as a cationic polyacrylamide, and passing the slurry onto a first flooded section of the support wire to form an open, entangled, structural mass having water in interstitial spaces of the entangled mass. Water is stripped from the mass and the mass dried without collapse of the open structure by passing heated dry air through the open entangled structure.

Abstract: There is disclosed a novel cellulosic web and a method for its manufacture. The web is fabricated of fibrous material and is characterized by one of its surfaces being nubby. Such web is formed by the deposition of fibers from an aqueous slurry onto the surface of a multiplex forming fabric defining pockets in one surface thereof, under conditions of flow and rate of water removal that establish high shear fluid flow and result in the orientation of fibers and/or fiber segments at an angle with respect to the plane of the forming fabric. The resultant web has a high apparent bulk and good absorbency and strength properties.

Abstract: Low density mineral wool structural panels are manufactured by frothing a dilute aqueous dispersion of mineral wool, lightweight aggregate, binder and a small amount of amine-based cationic surfactant onto a non-woven scrim cover sheet, dewatering the mass and drying it. The froth is a mass of weakly resilient bubbles that rapidly dewater and burst to concentrate the solids in the mass. The bubbles are readily broken without loss of the voided structural configuration by a first application of brief pulses of high vacuum followed by further dewatering under vacuum and rapid drying by passing large volumes of air through the voided mass without collapse of the structure to result in lightweight structural mineral wool panels.

Abstract: Disclosed is an elongate, nonwoven flexible sheet structure and a method for its manufacture. The sheet structure consists essentially of a commingled mixture of about 45 to about 70% by weight short fibers of aromatic polyamide and about 30 to about 55% by weight fibrids of poly(meta-phenylene isophthalamide). The sheet structure has an interior thickness remote from the edges of between about 75 and about 150 microns with a thickened area along and adjacent each of the side edges having a maximum thickness which is at least about 5% greater in average thickness than the interior thickness of the sheet along and adjacent the thickened areas.

Abstract: A method for the manufacture of very low density mineral wool structural panels on a moving foraminous support wire by frothing a dilute aqueous dispersion of mineral wool is disclosed. The forth, a mass of delicate, non-resilient and non-uniform bubbles among the entangled mineral wool fibers readily breaks, is stripped of water and dried without substantial loss of the highly open, porous structural configuration by a first controlled rate of maturation dewatering followed by brief pulses of high vacuum. Then the open structure is rapidly stripped of remaining water and dried by passing high volumes of heated dry air through the structure with continued vacuum. The drainage water may be recycled in the process to maintain a low level of binder and any frothing aid additions.

Abstract: A method for hydroentangling nonwoven fibrous sheet material to significantly increase the strength thereof at low latex add-on values employs small diameter jets of high-pressure water in the form of coherent streams that concentrate the hydraulic energy over a distance equal to approximately the diameter of the fibers being entangled. While fiber entangling water jets have been utilized heretofore, the present invention employs a relatively lower pressure for the fiber rearrangement along with a synergistic effect of wood pulp and long polyester fibers coupled with small amounts of latex to achieve the unexpectedly high strengths within these light weight materials. The resultant sheet material possesses excellent uniformity of fiber distribution and improved strength characteristics over those typically obtained from prior art water jet enganglement processes requiring 300-2000% the enganglement input energy employed in this process.

Abstract: A method of and arrangement for resisting formation of undulations in a fiber/water mixture supplied onto a forming wire at an open planar wire section of a paper-making machine include establishing over the wire an air curtain extending over the full breadth thereof, in the region of which the air mass upon the wire is set in motion. The direction of movement of the air mass is the same as the traveling direction of the wire, and the velocity of the air substantially equals the speed of the wire. The air curtain commences on the planar wire section, in the machine direction, only at a given distance from a lip slice of a headbox of the machine, and the air curtain extends along the traveling direction of the web over the planar wire section over a given distance.

Abstract: Continuous elimination of at least part of the liquid contained in a layer formed by depositing a liquid compound having a low solid matter content on a mobile, continuous, liquid-porous support, is effected by dripping, pressing and evaporation while the layer is maintained on the formation support without transfer. Evaporation means include means for passing a heated, gaseous flux through the layers.

Abstract: A method and apparatus are provided for the adjustment of the dewatering in the wire section of a paper machine. A fiber web is fed on to a forming wire, and the forming wire is passed over the surface of at least one dewatering means and a partial vacuum dependent on the difference in the speeds of the wire and said surface is created under the forming wire. An additional movable wire is positioned to move between the forming wire and the dewatering means and the dewatering is adjusted according to the kind of the fibre web to be dewatered, by adjusting the speed of the additional wire independently of the speed of the forming wire.

Abstract: A web-forming method is applied in a paper machine. The web-forming section which includes a lower wire loop having an initial single-wire run and dewatering zone in which the web is dewatered through and an upper wire loop having a joint run with a subsequent run of the lower wire to form a two-wire dewatering zone within which dewatering takes place substantially through the upper wire. A first open faced forming roll is situated within the upper wire loop so that the two-wire dewatering progress begins upwardly in the region of the first forming roll. A forming shoe within the lower wire loop has a curved deck whose center of curvature is situated on the side of the lower wire loop and further guides the joint run of the upper and lower wires in the two-wire dewatering zone. A second forming roll situated within the lower wire loop after the forming shoe guides the joint run of the upper and lower wires over a downwardly curved sector thereof.

Abstract: A method for operably adjusting a leading strip of a forming board of papermaking wire wherein the position and length of an impinging papermaking slurry is detected and the length of the leading strip adjusted.

Abstract: A papermaking machine including a non-dewatering forming board comprising a plurality of contiguous blades and a plurality of shower nozzles for showering stock carried by a forming medium over the forming board with a plurality of needle jets of water, each needle jet of water extending in a downstream direction, forming a small acute angle with the stock, and being in close proximity with the stock so that the needle jets of water impinge upon the stock as continuous streams.

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: Improved infusion web material for tea bags and the like is provided by using synthetic pulp in the heat seal phase and forming therein an array of a large number of small discrete craters. These craters, which exhibit an average planar area of at least about 1.times.10.sup.-3 square centimeters, are formed prior to drying the initially formed multi-phase material by directing a low impact mist-like liquid spray onto the heat seal phase. The droplets from the spray displace the fibers to form the shallow craters and, at times, expose portions of the underlying non-heat seal fiber phase. The small craters are present throughout the heat seal phase at a concentration of at least about 40 per square centimeter and occupy about 10-75 percent of the total exposed surface area of the heat seal fiber phase of the material. The web also is treated with a surfactant.

Abstract: A non-laminated paper sheet product characterized by regions or islands of increased thickness, usually located in the center of the sheet for more economical use of the paper product and for conservation of wood pulp. The regions of increased thickness are formed by depositing or laying additional pulp stock onto a generally uniform thickness paper web in the web-forming area of a paper machine in either wet or dry methods of paper production. Continuous regions of increased thickness in the web can be formed by corresponding variations in the width of the web or by spraying the additional pulp onto the forming web. Islands of increased web thickness can be formed by periodically interrupting pulp stock depositing sprayheads disposed at spaced locations across the width of the forming web, with timing devices or web thickness sensors controlling the sprayheads.

Abstract: This relates to the manufacture of wet process hardboard. The invention involves supplying additional heat curable resin to the mid-thickness regions of the panel by injecting additional resin into the moving mat as it is being formed on a forming surface. The region of injection of the resin is selected so that the bottom of the partially formed mat is sufficiently consolidated to resist the passage of resin therethrough while at the same time the top of the mat is still sufficiently liquid so that disturbances of the fibers of the partially dewatered mat caused by the injection of the resin have an opportunity to mend. The resin may be injected into the longitudinal marginal portions of the mat in continuous fashion such that, after the edges of the final board product have been trimmed, the resin treated areas are exposed to view. The additional resin reinforces the edge portions and assists in providing uniform caliper of the board across its width.

Abstract: A web dewatering concept which has particular utility in papermaking processes wherein overall compression and compaction of the paper web by mechanical means is avoided comprising a high pressure jet of compressible fluid such as air or steam emitting from a slot extending across the entire width of the web. The web is constrained between a pair of foraminous supporting members while it is passed across a slotted nozzle expelling a jet of compressible fluid at pressures up to about 50 psig. The jet of compressible fluid scrubs the free water from the spaces between the fiber matrix of the web and the foraminous supporting members. The edges of the slotted nozzle make intimate contact with and form a seal against the interior surface of the foraminous supporting member closest the nozzle. This causes direct penetration of the web and the carrying members by the fluid jet, thereby continuously expelling an atomized stream of moisture from the web.

Abstract: The characteristic profile of a paper web is adjusted on the fourdrinier by means of a number of fluid spray stations positioned across the papermachine. Each spray station is provided with two or more fan spray nozzles of different flow capacity oriented to impact the pond with fluid along a common line. Flow to each nozzle is binary controlled with respective binary command, full flow valves. By discrete manipulation of valve selection, total flow rate to the web may be adjusted without flow throttling and consequent impact velocity variations.

Abstract: Hard and medium density board made of lignocellulosic fibers having a central layer with substantially higher concentration of set resin than both the outer layers of said board have as good strength properties as a corresponding board having said higher concentration of said resin throughout the thickness of the board. Said board is produced by introducing a thermosetting resin solution or a high resin content pulp into and evenly across the width of the central layer of the pulp or the wet lap to be pressed and heat treated, the pressing period being shortened as well as the press cycle. Said process can be carried out with an apparatus including a member to be inserted in the pulp slurry flow in the headbox of a board machine or in the flow on the moving continuous wire screen of the board machine comprising an element having nozzles or slits through which a thermosetting resin solution or a high resin content slurry can be brought to flow.

Abstract: A slurry of cellulosic material is diluted to a flowable consistency and subjected to a pressure differential on a permeable surface to increase the slurry consistency to a value between the consistency of the diluted slurry and the consistency of the slurry prior to dilution thereby forming a mat of cellulosic material on the permeable surface. The liquid and solids which pass through the permeable surface as a result of the pressure differential are recycled for use as slurry diluent, and to the mat of cellulosic material, while the mat remains on the permeable surface and subject to the pressure differential, is countercurrently applied, in a plurality of treatment stages, a treating liquid, such as a wash liquid, including application of a fresh treating liquid to said mat in the last stage of said treatment stages, whereby the treating liquid displaces at least a portion of liquid present in said mat from said mat and through the permeable surface in each treatment stage.

Abstract: A web-forming method and apparatus particularly suited for cellulose pulp. The web is initially formed on a rotary wire cylinder which has a horizontal axis and a crest situated at the highest part of the cylinder over the horizontal axis, the cylinder during rotation thus having an upwardly travelling side which turns upwardly toward the crest and a downwardly travelling side which turns downwardly from the crest. At the upwardly travelling side of the cylinder is a headbox having its slice situated adjacent the crest for projecting onto the rotating cylinder a pulp slurry jet at a speed greater than the peripheral speed of the cylinder, so that the deposited pulp slurry will start to form a web while turning with the cylinder up to and then downwardly from the crest thereof. An outer wire has a portion wrapped partially around the cylinder, through an angle of at least 180.degree.

Abstract: A slurry of cellulosic material is diluted to a flowable consistency and subjected to a pressure differential on a permeable surface to increase the slurry consistency to a value between the consistency of the diluted slurry and the consistency of th slurry prior to dilution thereby forming a mat of cellulosic material on the permeable surface. The liquid and solids which pass through the permeable surface as a result of the pressure differential are recycled for use as slurry diluent, and to the mat of cellulosic material is applied a treating liquid, such as a washing liquid.

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: A tufted nonwoven web material exhibiting high loft, bulk and absorbency is made by a papermaking technique using an apertured, plate-like, fiber-collecting element having a structure appropriate to preventing entanglement between adjacent tufts prior to removal from the element. The apertured element is adapted not only to form the tufted nonwoven fibrous web but also to permit consolidation of individual tufts and facilitate the formation of tufted webs from 100 percent wood pulp. Additionally, webs having tufts on both planar surfaces also can be formed by this technique.

Abstract: A Fourdrinier steam shower positioned over the wire includes a steam distributor pipe extending across the path of motion of the machine wire and fed with pressurized steam. This steam pipe is connected to support members in the Fourdrinier machine. Positioned around said steam pipe for the width of the machine wire is a steam distributor including legs extending downward and outward from the pipe at an angle so as to define and enclose a steam chamber open at the bottom. Steam enters the steam distributor from jets in the steam pipe and is directed through a tortuous path into the steam chamber. Water collecting in the legs of the steam distributor is discharged through drains located at the bottom of each leg.