|Publication number||US3861996 A|
|Publication date||Jan 21, 1975|
|Filing date||Mar 16, 1971|
|Priority date||Mar 17, 1970|
|Also published as||DE2112395A1|
|Publication number||US 3861996 A, US 3861996A, US-A-3861996, US3861996 A, US3861996A|
|Inventors||Gerhard Walter Dorfel|
|Original Assignee||Ahlstroem Oy|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (7), Referenced by (38), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Umted States Patent [191 [111 3,861,996 Dorfel Jan. 21, 1975  PAPER WEB TRANSFER SYSTEM 2,709,398 5 1955 Beachler 162/306 CARRYING THE WEB FROM FORMING 3,207,657 9/1965 Wagner et al. 162/361 X 3,526,574 9/l970 Beachler,etal..... 162/358 X WIRE T0 PRESS SECTION 3,629,056 l2/l971 Forrest 162/305 75 Inventor: Ge h d W lter D fl 1 fg "16h" f f g FOREIGN PATENTS OR APPLICATIONS  Assigneez A. Ahlstrom Osakeyhtio, 565,550 ll/l958 Canada 162/360 Noormarkhv Finland Primary Examiner-S. Leon Bashore  Filed: Mar. 16, 1971 Assistant ExaminerRichard H. Tushin  Appl No 124 766 Attorney, Agent, or Firm-Brooks, Haidt & Haffner  Foreign Application Priority Data  ABSTRACT Mar 7 1970 Finland 714/70 Apparatus for transferring a paper web from a papermaking machine forming wire to a press section. A  Cl. 162/274 162/306 162/358 suction pick-up roll located adjacaent the forward run 162/366 of the forming wire is wrapped in part by a first end- Inti. less pick-Up felt picks the Wb up from the  Field of 'i; 16 210 360 forming wire and carries it through the first press nip "fag of the press section. Prior to contacting the paper web the first felt passes through a press nip (for liquid re-  References Cited moval) formed between the suction pickup roll and a press roll. A second felt (i.e., lower support felt) UNITED STATES PATENTS contacts the web carried by the first pick-up felt belii ii a1 162/113 x en the forming wire and press section. 1 spaug 2,694,346 11/1954 Goodwillie 162/306 X 1 Claim, 6 Drawing Figures PATENTEDJANZHQYB 3.86139 SHEETIUF 2 Fig. 3
SHEET 2 BF 2 Fig. 5
PAPER WEB TRANSFER SYSTEM CARRYING THE WEB FROM FORMING WIRE TO PRESS SECTION BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to the field of pressing a fiber web in a press section.
2. Description of the Prior Art Various arrangements have been introduced previously for the pressing of a paper web. US. Pat. No. 2,911,040 introduces a pressing part which is situated at a distance from the pick-up roll in the moving direction of the paper. The arrangement introduced in this patent has, however, the disadvantage that the part of the felt between the pick-up point and the first pressing point is under tension and the wet paper web stretches in this area. This takes place, in spite of the fact that the pick-up roll and the pressing roll rotate at the same peripheral speed, since slipping of the felt occurs at the pick-up roll. Due to stretching of the paper web, an orientation of the fibers takes place in the longitudinal direction which diminishes the longitudinal elasticity of the finished paper. Owing to the different longitudinal and transversal orientations of the fibers the finished paper sheet will not remain even.
SUMMARY OF THE INVENTION According to the invention the pick-up felt is pressed against the pick-up roll by means of a press roll to eliminate slipping of the felt and stretching of the web.
The paper produced in accordance with the invention has better elasticity than paper manufactured by prior known methods.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates schematically a press section of a paper machine for carrying out the method according to the invention, and
FIGS. 2-6 illustrate schematically alternative embodiments of the press section.
DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 13 is the wire of the web-forming part, from where the suction roll 2 working as a pick-up roll moves the paper web 12 with the suction effect of the roll to the endless felt 8. The suction roll, together with roll 1, forms a press nip through which the felt 8 runs. The felt and the paper web run to roll 3 at a distance from roll 2; roll 3 and roll 4 together form another press nip, where liquid is pressed out of the paper web 12. Thereafter the paper web is separated from the felt and it runs to the next pressing point which is formed by roll 4 together with roll 5. A suitable roll combination is a suction roll 3, a stone roll 4, and a grooved roll 5. The direction of the movement of the paper web is illustrated by arrows.
Because the felt runs through two press nips at a distance from each other, with no slipping occuring at the pressing points, it is possible, by choosing a somewhat lower peripheral speed for roll 3 than for roll 2, to obtain a longitudinal shrinking of the felt and thus also of the paper web between the pressing points, in which case the elasticity of the finished paper increases. FIG. 1 also illustrates the drying and cleaning devices of the endless felt 8 and the respective devices 16 of the pressing felt l4.
To keep the felt and the paper track essentially horizontal between the pressing points, an endless, synchronically moving, wire 9 can be placed below them. An arrangement like this is illustrated in FIG. 2. FIG. 5 illustrates a corresponding arrangement in a case in which the rolls 6 and 7 of the supporting wire 9 participate in forming the pressing points.
The felt and the web can be supported in other ways as well. In the application according to FIG. 3, a suction box 10 has been fitted above the felt to keep the felt part horizontal. In the case according to FIG. 4, a blowing device 11 has been respectively fitted below the felt; this device creates a cushion of air to support the felt part.
The pair of rolls 1 and 2 forms the so-called washing press of the felt and removes from the felt liquid that has been absorbed by it. Because the paper web is supported between rolls 2 and 3, the felt can be relatively dry there, in which case the proportionate dryness of the paper web, also, will be high after the first pressing point.
According to another embodiment, shown in FIG. 6, the paper web travels from the upper pick-up felt 8 running around the pick-up roll 2, to the lower support felt 9 at the pressing point formed by pressing roll 6, which is inside the lower felt, together with the pick-up felt. The paper track, supported by the lower felt, runs to the next pressing point formed by pressing roll 7, which is inside the lower-felt loop, together with pressing roll 3, onto which the paper web moves following the pressing point. Thus the embodiment of FIGS. 5 and 6 have in common the passage of the upper pick-up felt alone through a press nip, a second press nip through which the web is passed between two felts, and a third nip through which the paper web passes along with the support felt. In both of these cases the web is separated from the felt by appropriate guide means as shown by the arrows and the small rolls for the departing felts 8 and 9 in the two embodiments.
On the straight part of the felt between the pressing points of shrinking, or in certain cases also a so-called microcreping, of the paper web can be obtained which improved the elasticity of the paper. The pick-up roll is a positive one and the pressing roll in contact with it may also be positive. Both or one of the rolls of the pressing point after the straight felt part may be positive. The numbers of revolutions of the first and the second pressing points can be changed without gradation so that the speed of the felt at these points may be the same or greater at the first pressing point than at the second.
Suction rolls, rolls with different coatings, smooth rolls, or grooved rolls, in suitable combinations, can be used as pressing rolls, as in paper machines in general.
What is claimed is:
1. An improved press section in a web forming machine of the type having at least two traveling endless felts for contacting and carrying the web, which includes a pick-up roll urging a pick-up felt against the web for transferring the web to the felt, said pick-up felt passing around said pick-up roll and through a press nip for the pick-up felt defined between a press roll and said pick-up roll, a second press roll opposedly positioned to said pick-up roll and defining a second press nip between said pick-up roll and said second press roll through which the web, said pick-up felt and a support felt pass, the web being carried through said ing the web between said second and third press nips; one roll of each of said second and third press nips constituting a guiding roll for said support felt, and roll means for separating the web from the felt after said third press nip.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2043351 *||Jun 1, 1935||Jun 9, 1936||Int Cellucotton Products||Method of making a tissue paper product|
|US2204426 *||Jun 19, 1936||Jun 11, 1940||Sandusky Foundry And Machine C||Papermaking machine|
|US2694346 *||Mar 25, 1950||Nov 16, 1954||Beloit Iron Works||Web transfer assembly|
|US2709398 *||Jun 2, 1950||May 31, 1955||Beloit Iron Works||Suction transfer assembly with deckle edge control|
|US3207657 *||Jan 22, 1963||Sep 21, 1965||Huyck Corp||Method and apparatus for making paper by contracting the forming carrier to compact the web|
|US3526574 *||Mar 27, 1967||Sep 1, 1970||Beloit Corp||Vacuum transfer device in papermaking machine|
|US3629056 *||Apr 3, 1969||Dec 21, 1971||Beloit Corp||Apparatus for forming high bulk tissue having a pattern imprinted thereon|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4016032 *||Apr 14, 1975||Apr 5, 1977||Valmet Oy||Suction roll for transferring a web away from a press section|
|US4056433 *||Sep 15, 1976||Nov 1, 1977||Valmet Oy||Ascending twin-wire paper machine without web pick-up|
|US4059482 *||Sep 24, 1975||Nov 22, 1977||Valmet Oy||Paper machine pickup and crepe-setting press section|
|US4075056 *||Mar 8, 1977||Feb 21, 1978||Beloit Corporation||Press section structure|
|US4086131 *||May 6, 1975||Apr 25, 1978||Beloit Corporation||Method for pressing bagasse webs|
|US4110156 *||Jun 6, 1977||Aug 29, 1978||Escher Wyss Limited||Compact press at the web transfer position of a paper making machine|
|US4113557 *||Apr 14, 1977||Sep 12, 1978||Valmet Oy||Paper manufacturing structure particularly for detaching a web from a wire|
|US4163688 *||Apr 25, 1977||Aug 7, 1979||Valmet Oy||Apparatus for dewatering in a paper machine|
|US4172759 *||Sep 12, 1977||Oct 30, 1979||Valmet Oy||Paper-machine structure and method for subjecting a web to suction|
|US4188262 *||Feb 23, 1977||Feb 12, 1980||Valmet||Method for dewatering paper in a paper machine press section|
|US4197158 *||Mar 16, 1978||Apr 8, 1980||Beloit Corporation||Paper making machine press section|
|US4209361 *||Apr 25, 1977||Jun 24, 1980||Valmet Oy||Method of multi-nip pressing in a paper machine|
|US4257844 *||Mar 19, 1979||Mar 24, 1981||Beloit Corporation||Press section arrangement|
|US4285766 *||Oct 5, 1979||Aug 25, 1981||Valmet Oy||Press method in a paper machine|
|US4551203 *||Apr 2, 1984||Nov 5, 1985||Valmet Oy||Method and arrangement for guiding a paper web from the press section to the drying section|
|US4792381 *||Sep 11, 1987||Dec 20, 1988||Valmet Oy||Closed and compact press section of a paper machine with double S shaped path or mirror image thereof|
|US4909905 *||Jun 2, 1987||Mar 20, 1990||Valmet Paper Machinery Inc.||Closed press section of a paper machine and a frame construction for same|
|US4919762 *||Jun 17, 1988||Apr 24, 1990||Valmet Paper Machinery Inc.||Press section and press section/frame construction combination in a paper machine|
|US5308450 *||Apr 15, 1992||May 3, 1994||Sulzer Escher Wyss Gmbh||Press section of a papermaking machine|
|US5431787 *||Oct 25, 1993||Jul 11, 1995||Sulzer-Escher Wyss Gmbh||Press section of a papermaking machine|
|US5501775 *||Jan 21, 1994||Mar 26, 1996||J. M. Voith Gmbh||Wet press for a paper making machine|
|US5520782 *||Jan 21, 1994||May 28, 1996||J. M. Voith Gmbh||Method and apparatus for removing water from a web by means of presses|
|US5639351 *||Nov 22, 1994||Jun 17, 1997||Valmet Corporation||Press section of a paper machine, in particular for printing paper qualities|
|US5670023 *||May 27, 1994||Sep 23, 1997||Voith Sulzer Papiermaschinen Gmbh||Press of a paper machine for thin papers|
|US5705034 *||Mar 28, 1996||Jan 6, 1998||Voith Sulzer Papiermaschinen Gmbh||Method and apparatus for removing water from a web by means of presses|
|US5792318 *||Jul 20, 1997||Aug 11, 1998||Mancini; Ralph||Method to stabilize sheet between press section and dryer section of a paper-making machine|
|US5820731 *||Jun 10, 1994||Oct 13, 1998||Valmet Corporation||Method and apparatus in a paper or board machine for dewatering the web|
|US5830321 *||Jan 29, 1997||Nov 3, 1998||Kimberly-Clark Worldwide, Inc.||Method for improved rush transfer to produce high bulk without macrofolds|
|US5865954 *||Jun 18, 1997||Feb 2, 1999||Valmet Corporation||Method for dewatering a web in a paper making machine employing an extended nip press|
|US5888354 *||Apr 2, 1997||Mar 30, 1999||Valmet Corporation||Transfer of a web in a paper machine from a two-felt press nip to a dryer section|
|US5891308 *||Feb 2, 1996||Apr 6, 1999||Beloit Technologies, Inc.||Method of pressing a paper web of tropical hardwood fibers|
|US5951821 *||Sep 25, 1998||Sep 14, 1999||Valmet Corporation||Arrangement and method for transferring a web in a paper machine from a two-felt press nip to a dryer section|
|US6030499 *||Mar 20, 1998||Feb 29, 2000||Valmet Corporation||Method and apparatus in a paper or board machine for dewatering the web|
|US6090244 *||Jan 28, 1998||Jul 18, 2000||Voith Sulzer Papiermaschinen Gmbh||Press section|
|US6228216 *||Jul 10, 1998||May 8, 2001||Kimberly-Clark Worldwide, Inc.||Transfer of a cellulosic web between spaced apart transport means using a moving air as a support|
|US6260287||Apr 27, 2000||Jul 17, 2001||Raffaele Mancini||Wet web stability method and apparatus|
|US6368466 *||Nov 15, 1995||Apr 9, 2002||Valmet Corporation||Press section of a paper making machine employing an extended nip press|
|DE3942396A1 *||Dec 21, 1989||Jun 28, 1990||Tampella Oy Ab||Verfahren und anordnung zum leiten einer faserbahn von einem sieb durch eine pressenpartie|
|U.S. Classification||162/274, 162/360.3, 162/306, 162/358.1|