Paper making and fiber liberation – Apparatus – With cutting – scoring – perforating or tearing
Patent
1985-04-01
1987-03-10
Bashore, S. Leon
Paper making and fiber liberation
Apparatus
With cutting, scoring, perforating or tearing
162193, 162255, 162359, 34117, 226 92, D21F 700, D21F 504
Patent
active
046489428
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL AREA
The invention concerns a paper machine which is intended to be suited preferably for the production of mass papers (for instance printing paper, corrugated liners or similar) at maximum operating speeds.
STATE OF THE ART
1. DE-OS No. 33 33 040
2. WO No. 82/02937;
3. DE-PS No. 287 998;
4. DE-AS No. 25 38 846
5. DE-AS No. 23 65 438 (similar to U.S. Pat. No. 4,000,035);
6. WO No. 83/00514;
7. DE-OS No. 32 36 576.
The invention is based on the paper machine known from document 1. On that machine, the paper web runs successively through several press gaps and thereafter into the drying section, after it has been transferred from the web-forming screen with the aid of a felt belt. In each of the press gaps the paper web is located between two felt belts and is thus not in direct contact with any of the press rolls. Therefore, none of the press rolls needs to be a stone roll. (As generally known, a stone roll would in many cases have to be made from natural stone, causing extremely high cost. Besides, only a relatively low press force can be applied when using stone rolls.) Another advantage of the prior paper machine is that the paper web proceeding through the press section and transfering from the press section to the drying section is constantly supported by at least one of the felt belts and/or by the backing belt of the drying section, so that the still wet paper web is considerably less stretched in longitudinal direction than in other prior paper machines where an open draw exists between the press section and the drying section.
A similar prior paper machine is described in document 2. On this machine, the paper web runs together with the backing belt of the drying section first across the lower cylinder area of a first drying cylinder located within the backing belt loop. The arrangement according to document 1 is different: the paper web proceeds together with the backing belt first across the upper cylinder area of the first drying cylinder which is located outside the backing belt loop.
A disadvantage of the designs known from documents 1 and 2 is that the first "threading" of the paper web into the drying section (after a shut-down or web break) causes serious difficulties. Documents 1 and 2 do not mention this problem. The teaching of documents 3 and 4 is that a rope carrier be provided in the drying section with the aid of which a narrow edge strip of the paper web, the so-called transfer strip, is first introduced into the drying section. The remaining part of the paper web is passed from the web-forming screen or from one of the press rolls into a scrap container during this threading phase. Next, the transfer strip is broadened until it has assumed the width of the full paper web. As generally known, the rope carrier is located on the tending edge of the drying cylinders, and at that, outside the paper web width, with the entrance point into the rope carrier being arranged on or before the first drying cylinder. For that reason, the transfer strip must be deflected sideways from its normal path before the entrance point of the rope carrier (i.e., before the first drying cylinder). With the paper machines according to documents 1 and 2 this is difficult or not possible at all because the transfer strip runs on the backing belt as it enters the drying section. In other words:
The fact that the paper web runs according to documents 1 and 2 without open draw through the press section and from the press section into the drying section offers the advantage of reduced longitudinal stretching of the moist paper web, but grave disadvantages exist with regard to threading the paper web into the drying section.
SUMMARY OF THE INVENTION
The problem underlying the invention is improving the paper machines known from documents 1 and 2 to the effect that the "threading" of the paper web into the drying section can be performed with the aid of a rope carrier, without the above difficulties while the advantage of the continuous paper web backing with the correspondingly reduced longitudina
REFERENCES:
patent: 1104759 (1914-07-01), Sheahan
patent: 1676305 (1928-07-01), Weldon
patent: 1688267 (1928-10-01), Cram
patent: 1734879 (1929-11-01), Read
patent: 1789515 (1931-01-01), Cram et al.
patent: 3268390 (1966-08-01), Ely
patent: 3529755 (1970-09-01), Spangenberg et al.
patent: 4000035 (1976-12-01), Schiel et al.
patent: 4014740 (1977-03-01), Koponen et al.
patent: 4056433 (1977-11-01), Koponen et al.
patent: 4359827 (1982-11-01), Thomas
patent: 4501643 (1985-02-01), Kluru
patent: 4502231 (1985-03-01), Fissmann et al.
patent: 4526655 (1985-07-01), Karvinen et al.
patent: 4543160 (1985-09-01), Kurttula et al.
"Svensk Papperstidning", 1982, pp. 10-16.
"Wochenblatt fur Papierfabrikation", 1979, p. 17.
Hauser Ludwig
Wanke Wilhelm
Anderson Andrew J.
Bashore S. Leon
J.M. Voith & GmbH
Jeffers Albert L.
Niewyk Anthony
LandOfFree
Paper machine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Paper machine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Paper machine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1020452