摘要:
A papermaking machine is shown with an inner traveling screen and an outer traveling screen which are led towards each other to form a generally layered arrangement therebetween during a region of their joint travel and, in such region, the inner and outer screens are caused to pass over a portion of a water extracting or dewatering roller; a water collection apparatus situated outside of the roller serves to collect water centrifuged from the screens passing over the roller; and a preliminary water extraction zone preceeds the roller and such zone extends over a portion of, for example, a generally horizontal section of the inner screen.
摘要:
The paper machine comprises a horizontal cylinder, a slurry feed box opening onto the top side of the cylinder and the upper rim of the feed slice of which has been continued in order to form a roof-like upper lip between the feed slice and a feed roll placed on the cylinder at an approximate distance from the feed box in the direction of slurry flow, an endless felt or wire running from the feed roll along the cylinder towards the lower part of the same, an appropriate number of guiding and tension rolls for conducting said felt or wire back to the feed roll, a suction box or suction roll placed on the side of the feed roll opposite to that facing the cylinder and at the point where the slurry web and felt or wire depart from the cylinder surface, and possibly a compressed air box or equivalent placed above the felt or wire and after the feed roll, as seen in the direction of travel of the wire, approximately coincident with the gap remaining between the roof-like upper lip of the feed box and the wire. The horizontal cylinder is a suction cylinder which has therein a suction zone extending substantially from and including the upper roof-like lip continuously to the suction box or suction roll. The upper roof-like lip and suction cylinder form a first drying area for the slurry to form a partially dewatered web while the belt thereafter contacts the web against the surface of the suction cylinder over a major portion of the descending surface of the suction cylinder to form a second drying area in which suction and centrifugal force act upon the web to remove additional water.
摘要:
A portion of a papermaking machine is disclosed having several web-forming units in series for making heavy or multilayer paper. Each forming unit includes a headbox mounted above an impervious forming roll for discharging pulp into a nip between a pair of belts coming together and lapping a down turning side of the forming roll. Both belts may be wire fabrics or, preferably, one belt is a felt fabric making contact with the forming roll and the other belt is a wire and arranged radially outward of the felt. The pulp is formed into a web sandwiched between the radially inner felt and radially outer wire and water is squeezed from the pulp web outwardly through the wire. At the bottom of the forming roll the felt is located over the web and wire, and the felt-web-wire is removed from the forming roll and turned downwardly away from the forming roll and inverted to place the wire and web on top of the felt. The wire is lifted from the web and looped back to the forming roll while the web remains on top of the felt and is carried thereby through successive similar forming units for applying additional layers of pulp to the web.
摘要:
A technique for forming single or multi-layer sheets of fibrous material having a controllable fiber distribution is described. A pair of spraying rollers each having a system of circumferentially spaced radial vanes on its surface are supported within the upper portion of a working zone defined between a pair of continually advancing, downwardly converging sieves that are disposed symmetrical to a longitudinal axis. The rollers are rotated in respectively opposite directions to intercept at least one fibrous suspension downwardly directed into the working zone, and to thereafter propel the intercepted liquid outwardly and downwardly toward the sides of the working zone in symmetrical fashion. The fibrous layers thus built up on the advancing sieves converge into the final sheet in the lower portion of the working zone. Separate facilities are associated with the upper and lower portions of the working zone for drawing liquid from the formed layers outwardly through the sieves.
摘要:
A compound paper machine system for producing multi-layer paper webs which includes several web forming units and a common endless lower wire or felt therebeneath on which the individual webs are deposited. Each web forming unit may comprise a forming cylinder on which slurry is deposited from a headbox and a separate endless wire or felt which laps part of the upper surface of each cylinder and which is guided so as to deposit the individually formed webs onto the common endless lower wire or felt. Optionally the separate lapping wires or felts for each unit can be a single porous belt.
摘要:
A fibrous web is continuously formed between inner and outer endless foraminous forming belts between which stock slurry is fed from a headbox, the belts being held in tension as they wrap a first convexly curved forming run surface from which the outer belt is separated immediately following the forming run, the inner belt carrying the wet web then running over a second convexly curved surface from the offrunning side of which the inner belt is then separated and a porous pickoff belt is pressed by a substantial convex area of an imperforate pickup roll against the wet web on the inner belt, the inner belt being guided to diverge from the pickoff belt commencing at the off-running end of the convex area of contact of the pickup roll and the wet web being forced to adhere to the pickoff belt by the vacuum action of the imperforate surface of the pickup roll. By multiplication of the apparatus a multiply web can be formed. Either top delivery or bottom delivery of the wet formed web to the pickoff belt is provided for.
摘要:
Multi-ply web forming stock jets directed through a slice from a single headbox into a forming zone between converging forming surfaces in a papermaking machine are maintained separated for a sufficient interval after leaving the slice opening to permit drainage and partial ply formation of the stock delivered by one of the stock jets to one of the forming surfaces before the stock in a second of the stock jets joins in fiber felting laminar relation with the contiguous surface of the partially formed ply. Flexible divider sheet members divide the slice chamber of a headbox into separate flow passages aligned respectively with different ones of headbox subchambers to receive streams of the stock from the respective subchambers and maintain the streams separated, and the flexible members extend a substantial distance out of the slice opening in the direction of flow of the stock jets to maintain stock jets separated for a sufficient interval after leaving the slice opening.
摘要:
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.
摘要:
A process and apparatus for forming a multi-ply sheet of cellulosic fibrous material. A dry-laid mat and a wet-laid web of cellulosic fibers are joined together and concurrently the dry-laid mat is consolidated by the concurrent application of heat, pressure and moisture, the moisture being derived from the wet-laid web.
摘要:
A method and apparatus for making a multi-ply paper sheet wherein a first web is formed by wet-laying fibres and a second web is formed by dry-laying fibres, the two webs being combined to form a multi-ply sheet and wherein the dry-laid web is produced by depositing dry fibres on a supporting band and consolidating the web by hot moist pressing before transferring to the first wet-laid web.