摘要:
The invention concerns a method in the calendering of a paper or of an equivalent web material. In the calender, the web material (W) to be calendered is passed through nips (N1...N9) formed by a variable-crown upper roll (13a), a variable-crown lower roll (14a), and by two or more intermediate rolls (15a...22a) arranged between said upper and lower rolls (13a, 14a). The rolls (13a...22a) are arranged as a substantially vertical stack of rolls (12a). As the intermediate rolls (15a...22a), such rolls are used in which the form of the natural deflection line produced by their own gravity is substantially equal. The nip load produced by the masses of the intermediate rolls (15a...22a) and of the auxiliary equipment (167a) related to same is relieved substantially completely in the method, and an adjustable load is applied to the calendering nips (N1...N9) by means of the variable-crown upper or lower roll (13a, 14a) and/or by means of an external load (143a) applied to the upper or lower roll. The invention also concerns a calender that makes use of the method.
摘要:
The invention relates to a former-press section (100, 110) of a paper machine and to a method of transferring a web from a former to a press section. Between the former section (100) and the press section (110) there is a pre-press zone (PP) which removes water from the web (W) and through which the web (W) is passed as a closed draw from the former section (100) to the press section (110). The upper wet wire (10) or the equivalent transfer wire (10A) of the former section (100) is passed through the pre-press zone (PP), the web (W) being passed on the lower face of said wire into and through the pre-press zone (PP). Inside the loop of the upper wet wire (10) or of the equivalent transfer wire (10A) and/or inside the loop of the lower wet wire (20) there are transfer devices (15, 15a, 16, 26) based on the use of a pressure difference. The transfer devices (15, 15a, 16, 26) are arranged to operate in connection with threading or an operational malfunction such that the web (W) is separated from the upper wet wire (10) or the equivalent transfer wire.
摘要:
A paper or board machine having a double-felted first press nip and a double-clothed second press nip. According to the invention the first press nip has a suction roll (11) with a suction zone (49), the downstream end (51) of which is situated downstream of the press nip, the top felt (15) being separated from the bottom felt (13) at a point (P) before the downstream end of the suction zone. The bottom felt (13) of the first press nip carries the web to the second press (10) which has a top felt (22) which carries the web from the bottom felt (13) of the first press nip to the second press nip, which is an extended press nip. A pickup suction roll (24) is arranged in the top felt loop (22) of the second press (10) for transfer of the web from the bottom felt of the first press to the top felt of the second press (10). The latter bottom felt (13) leaves the suction roll (11) at the downstream end (51) of the suction zone (49) and is provided in its loop with suction boxes (17) situated at a point before the transfer of the web to the top felt of the second press. Heat-supply devices (40) are arranged outside the two top felts at points where one side of the web is exposed and the other side adheres to the top felts.
摘要:
Method and assembly for forming a paper or board web and a product made using the method. According to the method, the web (11) is made from fibers and then the web (11) is treated with pigment particles. The web is treated with microscopic pigment particles whose average size is so small as to permit the particles to adhere to each other by van der Waals forces. The particles are transferred to the web and adhered thereto advantageously using an ion-blast technique.
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 re-wetting 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:
The invention concerns a method for conditioning of a roll, in particular of a roll (10) in a paper machine or in a paper finishing device. In the method the face/coating on the roll of the paper machine is cleaned and/or ground. In the method, the cleanliness and/or condition of the roll (10) is/are measured continuously during operation and, based on the measurement results, the roll face/coating is cleaned and/or ground so that the roll (10) remains constantly in good condition and the level of quality of the paper remains at the desired level. The invention also concerns a device for conditioning of a roll, in particular of a roll in a paper machine and/or in a paper finishing device, which device (20) comprises means for cleaning and/or grinding the roll. The device (20) consist of an assembly (20) of devices which comprises a cleaning/conditioning unit (24, 23, 29), a control unit (33), and measurement units (30, 31, 32), and the device operates continuously and can be operated during running.
摘要:
The invention concerns a method for manufacture of paper, most appropriately for manufacture of glossy and porous paper for colour powder printing. In the method paper is manufactured by means of a paper machine. In the method the paper stock is fed out of the headbox (100) into the wire part (200), in which wire part (200) water is drained out of the paper web in both directions. In the method the paper web (W) is passed from the wire part (200) into the press section (300) in order to press water out of the paper web (W), and after the press section (300), the paper web (W) is dried in the dryer section (400) and coated/pigmented in the coating section (500), dried in an after-dryer section (600) and calendered in a calender (600), and reeled in a reel-up (800). The paper web (W) is made of layers in the Z-direction so that the desired distributions of additives and fillers are obtained in the different layers in the Z-direction of the paper web (W), and the paper web (W) is calendered in at least one calendering nip, which maintains or at least substantially retains the porosity of the web preceding the calendering. The invention also concerns a paper machine, most appropriately for manufacture of glossy and porous paper for colour powder based printing. The paper machine comprises a headbox (100), a wire part (200), a press section (300), a dryer section (400), a coating section (500), an after-dryer section (600), a calender (700), and a reel-up (800). The headbox (100) and the wire part (200) have been formed so that the desired layers with different compositions in the Z-direction are provided in the paper, and the calender (700) is a calender device that maintains or at least substantially retains the porosity of the paper web (W) preceding the calendering.
摘要:
A cleaning device in a paper or board machine, for cleaning a fabric therein, the fabric moving in a direction of movement. The device comprises a nozzle which directs a water shower or jet against the fabric which is to be cleaned, the nozzle including a first turning point, and wherein there is a first plane of the water shower or jet issuing from the nozzle. A plurality of water conduits which transport water to the nozzle. And, the nozzle being mounted so that the position thereof may be changed by turning the nozzle back and forth around the first turning point in the first plane, so as to change the direction of the water shower or jet discharged from the nozzle and so that the water shower is moved in a first linear movement.
摘要:
In the method in reeling of a paper or paperboard web, a web (W) is guided by means of a reeling cylinder (1) onto a reel (R) to be formed around a reeling axle (2). There are at least two reeling cylinders (1), both of which are used to reel in turn the web (W) onto the corresponding reel. The reels (R) are formed in turn in reeling stations located on opposite sides of the pair of reeling cylinders (1). The web (W) travels between the reeling cylinders (1) to either reeling cylinder (1) and the corresponding reel (R).