Abstract: A security paper for producing security documents, such as bank notes, identity cards or the like, having at least one opening, whereby the opening is produced during papermaking and does not have a sharp limiting edge in the edge area.

Abstract: A forming section has a lower wire loop (11), which constitutes a single-wire section (T) following a breast roll (12). A first dewatering zone (Z1) has at least one stationary, first forming shoe (40) followed by a pulsating strip cover (50). The first forming shoe has leading and trailing edges and underpressure affecting through holes of the cover. The holes are openings or slots substantially in the longitudinal direction of the machine, whereby non-pulsating dewatering is applied on the stock travelling on top of the lower wire. A pulp suspension jet is fed from a headbox (30) at an impact point after the shoe leading edge. The cover is straight at least in the area between the impact point of the pulp suspension jet and the trailing edge. The impact of the pulp suspension jet on the forming wire is thus better controlled in a better way, increasing production speed.

Abstract: The invention relates to an apparatus used in the formation of paper. More specifically the present invention is directed to an apparatus for maintaining the hydrodynamic processes involved in the formation of a fiber mat or paper sheet. The performance of this apparatus is not affected by the velocity of the paper machine, the basis weight of the paper sheet and or the thickness of the mat being formed.

Abstract: The present invention is directed to an apparatus used in the formation of paper. More specifically the present invention is directed to an apparatus, system, and method for lowering the consistency or degree of density of fiber suspension on the forming table, and improving the quality and physical properties of the paper formed thereon.

Abstract: A method for making a fibrous structure including a plurality of synthetic fibers disposed in a predetermined pattern and a plurality of cellulosic fibers generally randomly distributed throughout at least one layer of the fibrous structure. The method includes depositing an aqueous slurry including synthetic fibers and an aqueous slurry including cellulosic fibers onto a fluid-permeable forming member having a pattern of channels. The slurries are dewatered to form a fibrous web, wherein the at least some of the cellulosic fibers are randomly distributed throughout at least a portion of the fibrous web and a plurality of synthetic fibers are at least partially non-randomly distributed in the channels.

Abstract: A forming section of a paper or board machine 10 in the forming section of a paper or board machine has a cover 36 having an outlet groove 20 between a suction zone 18 of circular holes and an outlet edge 40. A wire comes to the cover area from an inlet edge 38 and leaves from an outlet edge 40. The outlet groove 20 is essentially in the cross-machine direction of the cover 36. The suction zone accomplishes non-pulsating dewatering, and the outlet groove accomplishes pulsating dewatering. The non-pulsating suction zone first accomplishes good retention, and after this formation is improved on the outlet groove. When pulsating dewatering takes place in the same direction as non-pulsating dewatering and immediately after non-pulsating dewatering, the web formed has a particularly good formation potential. Potential marking caused by non-pulsating dewatering can also be removed efficiently by means of pulsating dewatering taking place on the same side.

Abstract: A method for dewatering a fiber suspension in a twin-wire press is disclosed including feeding the fiber suspension to an inlet end of an elongated dewatering space, dewatering the fiber suspension during displacement of the endless lower and upper wires which form the elongated dewatering space by flowing filtrate through the endless lower and upper wires, collecting the filtrate in outlet boxes, and adjusting the pressure differential between the elongated dewatering space and each of the upper and lower outlet boxes by controlling the counter-pressure applied to the filtrate flow on both sides of the endless upper and lower wires directly adjacent the inlet end of the dewatering space. A twin-wire press is also disclosed therein.

Abstract: A non-woven mat of inorganic fiber is disclosed having a substance which is lower at the edges of the mat than in the remainder of the mat. Apparatus for making such a mat includes: a source of a slurry of inorganic fiber in a liquid; a forming wire disposed to move past the source, the liquid passing through the forming wire to deposit the inorganic fiber on the forming wire; a mask across a part of the width of the forming wire to hinder passage of the liquid through the forming wire over the part, the effectiveness of the mask varying in the direction of movement of the forming wire past the slurry source.

Abstract: A non-woven mat of inorganic fiber is disclosed having a substance which is lower at the edges of the mat than in the remainder of the mat. Apparatus for making such a mat includes: a source of a slurry of inorganic fiber in a liquid; a forming wire disposed to move past the source, the liquid passing through the forming wire to deposit the inorganic fiber on the forming wire; a mask across a part of the width of the forming wire to hinder passage of the liquid through the forming wire over the part, the effectiveness of the mask varying in the direction of movement of the forming wire past the slurry source.

Abstract: Fibrous stock is supplied by a paper or board machine headbox (1) between looped forming wires (11, 12). Water is removed in a first dewatering zone (Z1) formed with a fixed forming shoe (3) having a curved surface against which a wire (12) is supported while the opposite wire (11) is unsupported in the area of the shoe (3). Water is removed in a second dewatering zone (Z2) formed by fixed dewatering blades (21) on the other side of the wires (11, 12) and supported against the stock therebetween (21) and on the opposite side of the wires (11, 12) by dewatering blades (24), loaded in a controlled manner against the fixed dewatering blades (21) at gaps (22) between these so that pulsating dewatering is caused in the second zone (Z2). The wires (11, 12) are guided so the shoe (3) causes essentially non-pulsating dewatering in the stock.

Abstract: A method for making a fibrous structure, the method comprising the steps of: providing a mixture of synthetic fibers and short cellulosic fibers onto a forming member so as to form one or more layers including the mixture of synthetic fibers and short cellulosic fibers; providing a plurality of long cellulosic fibers onto the mixture of synthetic fibers and short cellulosic fibers so as to form one or more layers including predominantly long cellulosic fibers; and forming a unitary fibrous structure including the one or more layers including the mixture of synthetic fibers and short cellulosic fibers and one or more layers including predominantly long cellulosic fibers.

Abstract: The temperature of the ceramic elements of a supporting or wiping strip that is assigned to a wire or a felt in a paper production facility, is controlled by guiding a cooling carrier medium or a heating carrier medium through the supporting or wiping strip. For that purpose, the supporting or wiping strip is formed with at least one channel, through which the carrier medium for heat or for cold is pumped.

Abstract: A method and apparatus for transferring vibrational forces to a wire of a papermaking machine for forming a web on the wire and for dampening vibrations imparted to the papermaking machine. In some embodiments, the apparatus is a vibrational device including a vibrational device frame, a vibration isolator coupled to the vibrational device frame to dampen vibration transmission to the papermaking machine, a vibration-inducing mechanism coupled to the vibrational device frame and operable to generate a vibration having a frequency and positioned laterally with respect to the vibration isolator in the cross-machine direction, and a vibrational head coupled to the vibration-inducing mechanism and directly contacting the wire to impart vibration to the wire.

Abstract: The invention relates to a method of draining a fiber pulp suspension, where the fiber pulp suspension is applied to a convergent dewatering space arranged between two wires travelling in the same direction. In the dewatering space, water and powdery substance are removed from the fiber pulp suspension through the wires. Pressure pulses are generated in the fiber pulp suspension along the length of the dewatering space with pressure pulse elements that are on opposite sides of the wires relative to the fiber pulp suspension and in contact with or at a distance from the wires. The invention also relates to an apparatus according to the method.

Abstract: A screen (i) for use in forming a patterned paper by a wet-laying technique. The screen is of a mesh material (2) that is pervious to water and has formed therein repeats of pattern forming elements 3a–c, 4a–d and 5 which are defined by an area of at least partial blockage of the mesh and which are bounded by mesh that is not blocked to drainage. The pattern forming elements have a maximum are of 100 mm2 that is blocked to drainage. The screen may be used for producing patterned tissue paper from which tea and coffee bags may be produced.

Abstract: A variable frequency foil (VFF) box assembly and mechanisms for moving individual foils/foil beams and individual foil beam sets relative to each other to adjust the frequency of a paper making machine, and method of use are provided. The VFF box assembly allows for continuously and uniformly adjusting the pitch distances of individual foils within foil sets over a finite range, and also adjusting the distance between foil sets during the continuous operation of a paper making machine. Also provided is a variable frequency assembly comprising a combination of dewatering elements such as one or more foil elements and table rolls, a multi-surfaced foil element, and/or an adjustable angle foil element.

Abstract: A variable frequency foil (VFF) box assembly and mechanisms for moving individual foils/foil beams and individual foil beam sets relative to each other to adjust the frequency of a paper making machine, and method of use are provided. The VFF box assembly allows for continuously and uniformly adjusting the pitch distances of individual foils within foil sets over a finite range, and also adjusting the distance between foil sets during the continuous operation of a paper making machine. Also provided is a variable frequency assembly comprising a combination of dewatering elements such as one or more foil elements and table rolls, a multi-surfaced foil element, and/or an adjustable angle foil element.

Abstract: The invention relates to an arrangement for controlling the edge of pulp mass in a web former, the web former comprising a space formed by two wires or the like, into which space the pulp mass is fed. The wires or the like are supported on a chamber units, which each time include at least one chamber for receiving the water removed from the pulp mass. In conjunction with the side edge of the said web former are arranged pulp mass edge control means, which include an edge sealing part. The edge sealing part extends, in the lateral direction of the web former, by a distance between the chamber units in such a way that it will prevent the pulp mass edge from passing and/or spreading in the lateral direction of the web former into the area of the said edge of the web former. The invention also relates to a method for controlling the pulp mass edge in a web former.

Abstract: A screen (i) for use in forming a patterned paper by a wet-laying technique. The screen is of a mesh material (2) that is pervious to water and has formed therein repeats of pattern forming elements 3a-c, 4a-d and 5 which are defined by an area of at least partial blockage of the mesh and which are bounded by mesh that is not blocked to drainage. The pattern forming elements have a maximum are of 100 mm2 that is blocked to drainage. The screen may be used for producing patterned tissue paper from which tea and coffee bags may be produced.

Abstract: A forming board for a papermaking machine includes: a support; a transversely-extending lead blade attached to the support, the lead blade; a plurality of transversely-extending trailing blades; a mounting unit for each of the plurality of trailing blades, the mounting unit being attached to a respective trailing blade and to the support such that the upper surfaces of the lead blade and the trailing blades are substantially coplanar and such that gaps are defined between the trailing edges and leading edges of adjacent blades, the gaps being of substantially uniform width; and a drive unit attached to the mounting unit and to the support, the drive unit being configured to drive the trailing blades simultaneously to different longitudinal positions relative to the support, wherein the gap widths vary but remain substantially uniform.

Abstract: A tissue paper making machine, a tissue paper product, and a method for producing such a tissue paper product. According to the invention, a dewatering and sheet-forming wire (13;14) is deposited in the pulp flow area by a texturing wire (16;17) that is provided with a texture comprised of closed wire zones. This results in the production of a tissue paper product having improved optical and haptic properties.

Abstract: Method of producing paper having a three-dimensional pattern of alternating raised and recessed portions which is given the paper in connection with impulse drying, at which the wet paper web is passed through at least one press nip (12) comprising a rotatable roll (13) which is heated and that the paper web when passing through the press nip is given a three-dimensional pattern either by means of a pattern wire (11) and/or by the fact that the heated roll (13) is provided with a three-dimensional pattern, and where the wet paper web (10) before entering said press nip (12) is given a basis weight variation in a non-random pattern.

Abstract: The invention relates to a multi-layered soft paper web, and a method for forming such. A multi-layered soft paper web consists of at least one layer, showing basis weight variations in a pattern. A base-layer of a fibre furnish is firstly formed on a wire (2), whereupon at least one top layer is deposited on top of the base-layer, which is supported by a wire or the like (3, 13, 113, 1113) under the applying of the top layer, whereby the top layer is deposited with a fibre suspension jet, and the hereby deposited top layer is formed with twin wire technology. A pattern is created in connection with the forming of the base layer, or at least one top layer by local redistributions within the layer of at least one substantial part of the solid material in the fibre furnish, whereby the pattern in said layer is created under simultaneous dewatering, and that the local redistributions are dependent of the pattern as well.

Abstract: This invention relates to an improvement in coatings particularly suited for the preparation of paper products having an ink jet coating applied thereto and to the resulting paper products. The improvement in ink jet coatings resides in the incorporation of a primary amine functional polyvinyl alcohol (PVOH/PVNH2) as a polymeric binder. One form of an amine functional polyvinyl alcohol is produced by the hydrolysis of a copolymer of vinyl acetate and N-vinylformamide or vinyl acetate and allyl amine. Another is the polyvinyl butyral derivative of polyvinyl alcohol which typically is formed by the reaction of a 4-amino alkyl aldehyde dialkyl acetal, such as 4-aminobutyraldehyde dimethyl acetal with polyvinyl alcohol.

Abstract: A variable frequency foil (VFF) box assembly and mechanisms for moving individual foils/foil beams and individual foil beam sets relative to each other to adjust the frequency of a paper making machine, and method of use are provided. The VFF box assembly allows for continuously and uniformly adjusting the pitch distances of individual foils within foil sets over a finite range, and also adjusting the distance between foil sets during the continuous operation of a paper making machine.

Abstract: A web of tissue is formed in a crescent former, followed by an air press for water removal in the pressing section, passing onto a Yankee dryer. A headbox injects stock between upper and lower dryer fabrics brought together on a breast roll. The fabrics move over vacuum boxes, and the web is heated with steam and passed between an upper pressure box and a lower vacuum box forming an air press which dewaters the web. A sheet transfer pickup vacuum box holds the sheet to the upper fabric as the lower fabric diverges from the upper fabric. A pressure roller transfers the web onto a Yankee dryer. The fabrics are cleaned on vertical runs before returning to the breast roll. A second upper fabric or transfer fabric operating at a lower speed then the first can be used to form a rush transfer between the forming fabrics and the Yankee dryer which increases web bulk and absorbency. Instead of a second fabric, a vacuum pressure roll may perform the rush transfer between the lower forming fabric and the Yankee dryer.

Abstract: A mat containing highly machine direction oriented (90% or greater), discontinuous reinforcement fibers, is produced on inclined wire or rotary paper making machinery. Fibers are first uniformly dispersed in an aqueous medium containing thickeners and wetting agents. In one embodiment, antifoaming agents are also added to prevent floating fibers which entangle and reduce orientation. Thermoplastic fibers or particles may also be included. Stock is brought into an open headbox in a flow pattern which allows the fibers to decelerate before approaching the porous suction belt (wire). As the fibers approach the suction belt, the fibers begin to turn and align in the streamline so as to present one end toward the suction wire. The leading ends of the fibers are gripped by the moving belt which drags the fibers out of the dispersion stock in a straight line. The porous mat produced may be dried and bonded through hot air, heat and/or pressure, or chemical binders.

Abstract: A method and apparatus for generating turbulence in stock to deflocculate the stock in an open surface forming section of a paper making machine comprises a dewatering box providing vacuum assisted drainage and which has a set of dewatering elements that impart turbulence into relatively thick stock layers carried at machine operating speeds of equal up to about 400 m/min, for the production of paper products having a basis weight generally in excess of about 160 gsm. Each set of elements includes a lead-in element, at least one intermediate element, and a trailing element. The path of the forming fabric is deflected downwardly as it passes over the intermediate elements, which are inclined at an angle of from about 0.25.degree. to about 10.degree. from a plane defined by forming fabric supporting surfaces on the lead-in and riser elements. This vertical movement initiates turbulence and agitation in the stock, which acts both to deflocculate the stock and to diminish the possibility of sheet sealing.

Abstract: Improved method of removing water from a wet web of paper includes the steps of (a) passing the web and its supporting fabric above and in sliding contact with a surface of a meniscus separator unit having a plurality of spaced cells in contact with the inner surface of the fabric; (b) applying a small vacuum to an internal space of each cell to extract water from the web using the tension meniscus of water while preventing air from passing through the web; and (c) permitting air from the atmosphere only to be applied to the inner surface of the fabric by each cell and thence into the fabric to replace water removed from the fabric in step (b) thereby enhancing the removal of water from the web and from the fabric, the atmospheric air passing along and through the interstices between the inner and outer surfaces of the fabric to the internal space of each cell.

Abstract: A mat containing highly machine direction oriented (90% or greater), discontinuous reinforcement fibers, is produced on inclined wire or rotary paper making machinery. Fibers are first uniformly dispersed in an aqueous medium containing thickeners and wetting agents. In one embodiment, antifoaming agents are also added to prevent floating fibers which entangle and reduce orientation. Thermoplastic fibers or particles may also be included. Stock is brought into an open headbox in a flow pattern which allows the fibers to decelerate before approaching the porous suction belt (wire). As the fibers approach the suction belt, the fibers begin to turn and align in the streamline so as to present one end toward the suction wire. The leading ends of the fibers are gripped by the moving belt which drags the fibers out of the dispersion stock in a straight line. The porous mat produced may be dried and bonded through hot air, heat and/or pressure, or chemical binders.

Abstract: A drainage device and method which provides for drainage from paper or pulp stock on a fabric in a sheet or mat making machine which includes a primary blade and trail blade with a gap therebetween for drainage wherein the size of the gap controls drainage and the primary blade is so configured so as to force a portion of the drained liquid through the fabric to create paper stock activity and disbursement while minimizing turbulence and maintaining laminar flow in the machine direction along with providing reinforcement of CD shear.

Abstract: Improved system for controlling the forming and dewatering of a web of paper by submerged drainage in which air does not penetrate the fiber/aqueous dispersion and the formed web. The dewatering is via altering the natural tension of the meniscus of the water to induce enhanced drainage of water from the aqueous dispersion of paper making fibers in the wetter end of the system and from the drier end of the fabric. Also, the improved horizontal system provides substantially equivalent side surfaces to the paper formed in such system.

Abstract: A method of producing a nonwoven fiber glass mat that contains discrete areas which are of different construction than the remainder of the mat. The permeable forming screen onto which a fibrous aqueous slurry is deposited is of a different structure in areas corresponding to the discrete areas of the mat so as to restrict the flow of water through those areas. Less fiber is deposited in those areas, resulting in the discrete areas being comprised of a thinner mat. The orientation of fibers within the discrete areas can be controlled by correlating the restricted flow of slurry in these areas to the flow of slurry necessary to cause this condition.

Abstract: A paper making machine forming board is described wherein the rate of drainage of the stock through the forming fabric is curtailed and controlled by applying a low positive air pressure (above ambient atmospheric) to the machine side of the forming fabric. Additionally, a controlled level of agitation is induced in the stock on the forming board, providing better initial paper formation.

Abstract: A method and apparatus are disclosed whereby the rate of drainage of the stock on a Fourdrinier paper making machine can be controlled for the full length of an open surface forming section. A continuous sealed drainage box is used from adjacent the head box slice to the end of the forming section, within which the air pressure can be controlled. In the area adjacent the head box slice drainage is hindered by the use of a positive (above ambient atmospheric) pressure, while further along the forming section the pressure is decreased to a negative value (below ambient atmospheric). Improved paper formation and first pass retention are obtained.

Abstract: In a Fourdrinier paper making machine a dispersion roll mounted between the headbox and the suction and dewatering means, underneath in contact with the Fourdrinier travelling fabric and extending laterally across the width of the fabric, and adapted to rotate at about the same speed as that of the fabric; the roll having a fluted surface of alternating lands and grooves, and a plurality of spaced, parallel, lateral slots across each said land to communicate each groove with the next adjacent groove. The function of the roll is to vibrate the travelling fabric and cause better dispersion of the paper fibers.

Abstract: The invention is directed to a method for extracting water from a paper web in a paper making machine using a ceramic foam component. The component includes a supporting structure and a water permeable member is mounted on the supporting structure and is adapted to support a paper web. The water permeable member comprises a rigid mass of ceramic foam having a plurality of interconnected cells. The ceramic foam has an air permeability in the range of 10 to 1,000 cubic feet per square foot of surface area per minute and has a density of 5 to 100 lbs/cubic foot. When a pressure differential is applied to the permeable member to the paper web, moisture will be extracted from the web and passes through the permeable member.

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 method for forming a paper web by which web formation is improved and flocculation in the web is reduced includes the steps of feeding steam under pressure into the fiber suspension when the suspension enters into the gap of the former and as web formation is initiated over the perforated mantle of the forming roll. The steam is fed from a steam supply chamber or the like provided within the forming roll through the perforations in the roll mantle within a steam supply sector of the roll mantle. The steam feed is applied to the pulp web when the web is still substantially uncouched and in a manner such that when the steam condenses in the pulp suspension, an implosion is generated in the pulp suspension which produces high frequency mechanical vibrations which can be closely controlled to achieve the desired effects. A twin-wire former and forming roll therefor for applying the method are also disclosed.

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: A process in the forming of a paper web, the dewatering of the pulp web, and of the paper web being formed comprises feeding the pulp suspension jet from the slice of the headbox into a gap formed by two wires, the gap becoming narrower in the feeding direction of the pump suspension jet. Water is removed from the pulp web when the web is in compression between the carrying wire and the covering wire within the twin-wire forming zone, which begins immediately after the feeding gap. The twin-wire forming zone is curved towards the loop of the carrying wire with a curve radius which is selected large enough so that the wire tensioning pressure resulting from it and acting upon the pulp web becomes low and the water removed from the pulp web is not splashed from the inside surface of the wire loop by the effect of centrifugal force dependent upon the curve radius.

Abstract: A process for making a cement and non-asbestos fiber mat on a Hatschek machine having a cylinder vat, a cylinder in the cylinder vat, and a porous surface on the cylinder on which the mat is formed and through which drainage water passes including the steps of introducing a slurry of cement and non-asbestos fibers and clay and poly(ethylene oxide) and water into the cylinder vat, and maintaining a lesser portion of the porous surface in engagement with the cement and non-asbestos slurry than the portion of the surface which is otherwise normally engaged by a cement and asbestos slurry of the same depth to thereby form the cement and non-asbestos fiber mat on the lesser portion of the porous surface and thus provide a lesser area for the slurry to drain than the area through which a cement and asbestos slurry drains, the poly(ethylene oxide) and clay causing the drainage water to be substantially clear and not to have any appreciable amount of cement fines, the cement and non-asbestos fiber mat containing Port

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 method and apparatus are disclosed for influencing the fibers in the uppermost layer of a fibrous web lying on a screen, for example, in applying a watermark or evening the surface of the web, wherein a surface compression is exerted on the web by a screen roller and a second screen guided around the screen roller. The surface compression is maintained over a variable time period and causes a water film to appear on the upper surface of the web, in which the fiber density is much less than in the web prior to the surface compression. This water layer is forcibly aspirated from the web and the fibers therein thus experience a reorientation and become set in desired positions.

Abstract: The wet end of a fourdrinier paper machine includes a transversely disposed roll beneath the wire. The roll is shaped and mounted for rotation at a speed which is different from the speed of the wire to create pulses of negative pressure beneath the wire for drawing liquid from the web of fibers formed thereon. Also disclosed is a fin apparatus transversely disposed beneath the wire to create a wave of positive pressure thereunder to urge the formed web off of the wire.

Abstract: By imposing pressure pulses on mobile fibers in suspension in paper making stock slurry in the primary drainage area of the forming zone of a roll former substantially uniform distribution of the fibers is effected in forming of the paper web. A device for effecting the pressure pulses is located adjacent to the primary drainage area and may comprise a pressure pulse producing element of selected shape to control the length of the pressure pulse for the particular character of paper making fiber stock slurry involved in the paper web being formed.

Abstract: A nonwoven fabric having alternating stripes of high fiber density and low fiber density has fibers of at least 1/2 inch in length and fibers of less than 1/2 inch in length, preferably under 1/4 inch in length. The fabric is made in such a manner as to produce parallel twistless ribbon strands in the high fiber density areas containing both short and long fibers. The twistless ribbon strands are bridged together by the long fibers so as to form the nonwoven fabric. A majority of the bridging long fibers have at least a portion of their length included in adjacent twistless ribbon strands; said ribbon strands having at least one strand width space between said ribbon strands.

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.