摘要:
A method and an arrangement for controlling evaporation and moisture in a multinip calender (10) when a continuous fibrous web (W) is calendered in calendering nips (1,_2,—3,—4,—5) placed one after the other before the fibrous web is wound on a reel-up/winder (9). With a view to making the net evaporation from and the final moisture content of the web (W) constant when the running situations in the calender (10) change, the web is passed in the calender from the outlet of at least one nip into an air-float chamber (20) of the turning airborne type.
摘要:
A paper or board web (W) is calendered in at least one calendering nip (N1-N8), and the web (W) is moisturized before calendering. The web (W) is moisturized by means of liquid moisturization (20; 21) very close before at least one calendering nip (N1, N5). A calender for calendering a paper or board web has at least one liquid moisturizing calendering nip (N1-N8) and at least one device (20; 21) for moisturizing the web (W) is placed very close before at least one calendering nip (N1; N5).
摘要:
A multi-roll calender for controlling the moisture gradient of a fibrous web and for enabling the manufacture of high quality paper grades, such as WFC, LWC-roto and SC-A by on- and off-line calendering. An on- or off-line multi-roll calender formed of separate sets of rolls is used for calendering, and the fibrous web (W) is subjected to intermediate moistening between the sets of rolls (A, B).
摘要:
The moisture profile and/or moisture gradient of a paper web of at least SC quality paper is controlled in a paper machine comprising a calender (1) which has at least two roll stacks (21, 22; 31, 32), one stack has at least three rolls and another has at least five rolls. The web is moisturized to a desired pre-moisture content M1 by a pre-moisturizer (7) before the calender. At least one intermediate moisturizer (3) is arranged between two roll stacks moisturizes the web to a desired intermediate moisture content M2 before the last roll stack (31, 32), in which the web is dried to a desired final moisture value M3. For continuously controlling and optimizing the moisture profile and/or moisture gradient of the web, the pre-moisturizing W1 of the web is controlled by a pre-moisturizer (7) control parameter which corresponds to the final moisture value M3 of the web.
摘要:
In a paper/board or finishing/converting machine, a calender (1) comprises a number of rolls (2, 3) formed into a roll stack, and a number of lift-out rolls (4), which are arranged in such a way that the web (W) being treated travels from one calender (1) nip (N) to another via a lift-out roll (4). Between the calender (1) roll (2, 3) and the lift-out roll (4), the web (W) being treated is supported by means of at least one closing member (5, 5′, 6) not extending through the nip (N), which closing member is formed by a belt, wire or metal wire (7), which is arranged to travel via two or more guide rolls (4, 8).
摘要:
The moisture profile and/or moisture gradient of a paper web of at least SC quality paper is controlled in a paper machine comprising a calender (1) which has at least two roll stacks (21, 22; 31, 32), one stack has at least three rolls and another has at least five rolls. The web is moisturized to a desired pre-moisture content M1 by a pre-moisturizer (7) before the calender. At least one intermediate moisturizer (3) is arranged between two roll stacks moisturizes the web to a desired intermediate moisture content M2 before the last roll stack (31, 32), in which the web is dried to a desired final moisture value M3. For continuously controlling and optimizing the moisture profile and/or moisture gradient of the web, the pre-moisturizing W1 of the web is controlled by a pre-moisturizer (7) control parameter which corresponds to the final moisture value M3 of the web.
摘要:
In the method for treating the surface of the web, liquid is added on the surface of a paper or paperboard web (W), possibly with other constituents. The absorbency of the surface of the paper or paperboard web is increased before liquid is brought on the surface of the web or simultaneously with bringing the liquid on the surface of the web. The method is used for wetting the surface of the web before calendering, or for coating the web in surface sizing or pigmenting. The absorbency of the surface is increased before bringing the liquid for example by means of a corona treatment, a flame treatment, an ozonization or by adding steam.
摘要:
A method for a multi-roll calender and a multi-roll calender for controlling the moisture gradient of a fibrous web and for enabling the manufacture of high quality paper grades, such as WFC, LWC-roto and SC-A by on- and off-line calendering. An on- or off-line multi-roll calender formed of separate sets of rolls is used for calendering, and the fibrous web (W) is subjected to intermediate moistening between the sets of rolls (A, B).
摘要:
In the method for manufacturing surface-treated printing paper, a paper web is first dried down to a target moisture of the surface treatment, and it is wetted again to the target moisture before the surface treatment. The rewetting to the target moisture is conducted on the web running to the surface treatment before a device effecting the surface treatment of the web, as seen in the travel direction of the web. Before re-wetting, the moisture profile of the web is adjusted in the drying section by wetting the web at a point which is located before the area of the heavy shrinkage (cd shrinkage area) in the travel direction of the web.
摘要:
A method and apparatus for manufacturing calendered paper in which the paper is calendered after drying. The paper is dried (D) sown to a moisture lower that the target moisture of calendering. The paper is run via wetting (1) to calendering, wherein at least one of the surface layer of the paper is wetted in the wetting in such that the moistening water is absorbed in the surface layer of the paper while at lest the central part remains substantially dry. From the paper wetted at least on one of its sides, gradient paper is manufactured by means of gradient calendering by restricting the paper-molding effect of the calender to the wetted surface layer in such a way that at least the paper is elastically restored substantially in its original state, whereafter the obtained gradient paper is reeled.