Paper making and fiber liberation – Processes and products – Non-uniform – irregular or configured web or sheet
Reexamination Certificate
2003-05-06
2004-03-30
Fortuna, José A. (Department: 1731)
Paper making and fiber liberation
Processes and products
Non-uniform, irregular or configured web or sheet
C162S205000, C162S111000, C162S206000, C100S038000
Reexamination Certificate
active
06712930
ABSTRACT:
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER
FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The invention relates to methods for calendering tissue paper in general, and more particularly to tissue paper calendering methods involving at least one long belt calendering nip.
Tissue papers contain various sub-grades of silk and tissue papers, such as toilet papers, facial tissues, handkerchief tissues, napkin tissues and wipe-off papers, including e.g. industrial towels, towel papers for use in the kitchen and other towel papers. As is known in the state of the art, tissue papers are conventionally calendered in calendars with a hard nip. The main purpose of calendering is to control the CD (cross direction) thickness. Calendering is performed at very low loads and at a low temperature. In tissue making, calenders are also used in order to bring together the various layers of multi-layer tissue papers before rolling. In connection with the manufacture of some tissue paper grades it has been known to use soft calendering in the calendering of tissue paper, whereby the calendering takes place in a calendering nip, where at least one roll is a so-called soft roll.
U.S. Pat. No. 5,980,691 presents a soft tissue paper with a high density and a method for its manufacture. This publication makes known calendering of a tissue paper web in the calendering nip in such a way that a tissue paper is obtained, the evenness or uniformity of which is less than or equal to 800 microns. In this publication, such a calendering nip is used in the calendering, wherein one roll or both rolls are of steel, surface-coated with rubber, fabric or paper. One roll or both rolls are kept at a temperature, which is optimum for the useful life of the roll in order to prevent overheating of the roll.
As regards the state of the art relating to the invention, reference is also made to Patent Publication WO-9923305, which presents a belt calender, wherein the nip is formed in between the belt and the roll. The belt material used in belt calenders is usually considerably softer than the surface material of soft rolls used in soft calenders.
As is known, the belt material of belt calenders is about ten times softer than the softest surface-coatings of rolls, and it is known in the state of the art that by soft calendering it is possible to achieve significant advantages compared with hard-nip calendering, which is the most commonly used method at present. It is also known that with some paper and board grades the belt calendering concept gives significant advantages in the paper quality compared with soft calendering than soft calendering gives compared with hard-nip calendering. One of the major advantages with board grades is the saving in bulk, since the treatment is very soft and low pressures are used.
SUMMARY OF THE INVENTION
The invention aims at bringing about a new method for calendering of tissue paper, with which maximum bulkiness and softness of the tissue paper are achieved.
REFERENCES:
patent: 2021975 (1935-11-01), Wrigley et al.
patent: 2624245 (1953-01-01), Cluett
patent: 2667910 (1954-02-01), Grettve
patent: 2997406 (1961-08-01), Freeman et al.
patent: 3148108 (1964-09-01), Cluett
patent: 3266972 (1966-08-01), Cramer et al.
patent: 3329562 (1967-07-01), Schaefer
patent: 3515633 (1970-06-01), Futch, Jr.
patent: 3908071 (1975-09-01), Heim et al.
patent: 4701368 (1987-10-01), Kiuchi et al.
patent: 4908103 (1990-03-01), Cronin et al.
patent: 5163364 (1992-11-01), Bubik et al.
patent: 5251551 (1993-10-01), Abe et al.
patent: 5352022 (1994-10-01), Knoblock
patent: 5400707 (1995-03-01), Neider et al.
patent: 5694837 (1997-12-01), Neider et al.
patent: 5830321 (1998-11-01), Lindsay et al.
patent: 5836242 (1998-11-01), Aberg
patent: 5980691 (1999-11-01), Weisman et al.
patent: 6076281 (2000-06-01), Kilpia et al.
patent: 6077390 (2000-06-01), Salman et al.
patent: 6103062 (2000-08-01), Ampulski et al.
patent: 6158334 (2000-12-01), Sáfman et al.
patent: 6193839 (2001-02-01), Ampulski et al.
patent: 6287424 (2001-09-01), Mohan et al.
patent: 6287426 (2001-09-01), Edwards et al.
patent: 6332953 (2001-12-01), Singh et al.
patent: 6397739 (2002-06-01), Viljanmaa
patent: 6418840 (2002-07-01), Viljanmaa
patent: 6440268 (2002-08-01), Baggot et al.
patent: 6551453 (2003-04-01), Weisman et al.
patent: 6598521 (2003-07-01), Wikström
patent: 2236829 (1998-12-01), None
patent: 299 02 451 (1999-07-01), None
patent: WO 99/23305 (1999-04-01), None
patent: WO 02/04743 (2002-01-01), None
Search Report issued in Finnish Priority Application No. 20001637.
International Search Report issued in International Application No. PCT/FI01/00643.
International Preliminary Examination Report issued in International Application No. PCT/FI01/00643.
“OptiDwell shoe nip calender” Metso Paper, Inc. Brochure.
“Metso Paper Calenders, Järvenpää, Finland 2002” cover sheet and pp. 24 and 30.
Fortuna Jos'e A.
Metso Paper Inc.
Stiennon & Stiennon
LandOfFree
Method for calendering tissue paper does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for calendering tissue paper, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for calendering tissue paper will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3238218