JP2003522857A - Method and apparatus for calendering paper including a heatable roll - Google Patents

Abstract

A method and a device for calendering paper in a calender which comprises at least one calender unit (10; 110) in which a first calendering nip (N1; N3) is formed between a heatable calender roll (16; 116) and an extended-nip roll (12; 112), which nip is an extended nip, through which a paper web (W) is guided to run in order to calender the paper on at least one side. In the calender unit (10; 110), a second calendering nip (N2; N4) is formed with the heatable calender roll (16; 116) and a third calender roll (17; 117), which nip is a roll nip, and the paper web (W) is guided to run through said roll nip (N2; N4) such that, in both calendering nips (N1, N3; N2, N4), the same side of the paper web (W) is in contact with the heatable calender roll (16; 116).

Description

Detailed Description of the Invention

The present invention relates to a method for calendering paper in a calender in which a first calendering nip comprises at least one calendering unit formed between a heatable roll and an expanding nip roll, said nip Is an expanded nip through which the paper web is advanced to calender the paper on at least one side.

The invention also relates to a calender comprising at least one calender unit including a calender frame, a heatable calender roll and an extended nip roll provided in said calender frame, said rolls being first calenders relative to each other. Forming a hanging nip,
The nip is an expanded nip, which guides the progress of the paper web through the nip for calendering the paper on at least one side.

If it is desired to improve the level of calendering, then, in the conventional manner, the only possibility in the supercalender is, in fact, to increase the number of calendering nips. This makes the structure of the calendar more complex and also makes control of the paper web and tail threading more difficult. In particular, in the case of online machines, it is necessary to resolve the contradictions that arise from high operating speeds and full speed paper feed. Attempts have been made to solve these problems with various belt calenders and shoe nip calenders, whereby the calender nip is expanded and various belts and shoes are used, thus making the operation of the nip more efficient. Conventionally, for example, belt calendars are disclosed in Finnish Patents 95061, 102304, and 102305. The technology relating to shoe calendars is disclosed in German Published Patent Application 4
No. 344165 and US Pat. No. 5,163,364.

Belt calenders and shoe calenders, or the more general extended nip calenders, provide a quality gloss corresponding to supercalendered gloss, or at least a gloss that is fairly close to that obtained by supercalendering. Obtaining the corresponding smoothness is difficult. The maximum pressure in the nip of belt calenders and shoe calenders remains lower than the traditional nip formed between the two rolls due to the wider nip, so the extended nip calender is very important to maintain bulk. Most suitable for grade paper. The extended nip calendar has a low gloss (
It has been found to be particularly good at calendering graded paper up to 40% Hunter). If, obviously, high gloss is desired and required, the nip pressure provided by the extended nip calender by itself is not sufficient to produce gloss.

The object of the present invention is to provide a new method and a new calendar, which avoids the drawbacks of the prior art and provides an improved calendering result compared to the prior art.

In view of achieving this object, the method according to the invention mainly comprises, in the calender unit, a second calendering nip with a heatable calender roll and a third calender roll, the nip being a roll nip. , The paper web is guided through the roll nip, so that in both calendering nips both sides of the paper web come into contact with the heatable calender rolls.

In the calender of the present invention, the third calender roll is installed in the calender unit, the roll forms a calendering nip that is the second roll nip together with the heatable calender roll, and the paper web passes through the roll nip. It is characterized in that it is guided to proceed so that, in both calendering nips, the same side of the paper web contacts the heatable calender roll.

A second calendering nip, or roll nip, is formed in the calender unit on one side of the heatable calender roll as opposed to the expanded nip. A second calendering nip is formed by the third calender roll, which is advantageously a deviation compensating roll. The third calender roll may be provided with a soft roll cover depending on the calendering process requirement, in which case the second calender nip is a soft nip, or the roll is a hard calender. It may be a roll, in which case the second calendering nip is a hard nip.

The present invention has several advantages over the prior art, for example, in this connection: The properties of conventional calenders provided with expanded nip calenders and roll nips are combined in the present invention so that such expanded and low pressure nips, especially when the expanded and low pressure nip is used as the first nip of the calender. The nip allows heating and plasticizing to properly shape the paper prior to the subsequent roll nip. By this means, the bulk of the paper can be maintained without damaging other properties. At a standard gloss level, it is about 7 compared to the conventional super calendar application.
A% bulk savings can be obtained. The resulting benefits are based on longer nip dwell times and higher calendering temperatures. The calendering process is often a somewhat "rough" operation on the paper, but in particular, the calendering nip extended by the present invention, when used as the first nip of the calender, is a structure of the paper. With the result that it does not hurt in calendering, it does not exert as much pressure as a conventional roll nip. The strength properties of the paper remain good. The arrangement of the present invention provides a force parallel to the surface of the paper, and by the force parallel to the surface of the paper as well as its effect on the plasticization of the web, the smoothness of the calendered paper also , Which is better than the smoothness which is the standard of the past.
In particular, compared to today's soft calendering, improved microroughness and high gloss are considered benefits of the present invention, in addition to bulk retention. According to the invention,
The calendering can use the roll nip as the first nip and the expansion nip afterwards, if desired. Of course, the calendar could be used to use only one of the extended or soft nips. However, web caliper profiling is performed as a means of roll nip.
Other advantages and features of the present invention will become apparent from the description of the invention given below.
A further advantage is that the structure of the calender allows easy replacement of the extended nip rolls within the calender.

[0010]   Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall schematic side view of an embodiment of a calendar of the present invention, particularly for two sided calendaring.

FIG. 2 is a schematic side view of another embodiment of a calendar for two sided calendaring.

FIG. 3 shows the calendar of FIG. 2 in which the advancement of the web is pivoted such that the side of the web opposite that shown in FIG. 2 is first calendered.

FIG. 4 shows one calender unit of the calender shown in FIGS. 2 and 3 with the nip opened for the replacement of the expanding nip rolls.

The calendar shown in FIG. 1 includes two calendar units 10 and 110, which are arranged alternately in the traveling direction of the paper web W. A calender unit including the two calender units 10 and 110 shown in FIG. 1 is used when the paper web W is calendered on both sides. This type of paper, which is typically calendered on both sides, is, for example, the fine paper for offset printing. Of course, the present invention is also applicable to single-sided calendaring of paper web W, requiring only one of the calendar units shown in FIG. This type of paper, which is typically calendered on one side, is, for example, label paper.

The first calender unit 10 includes a calender frame 11, and in the calender frame 11, the expansion nip roll 12, a heatable calender roll that is a so-called heat roll 16, and a third calender roll 17 form a stack. It is installed. The roll 12, 16 and 17, each other to form a nip _{N 1} and the nip _{N 2,} the nip _{N 1} between the extended nip roll 12 and the heatable calender roll 16 is an extended nip, the heatable calender roll 16 a The nip N ₂ between the third calender roll 17 and the calender roll 17 is a roll nip. In FIG. 1, the extended nip roll 12 includes a roll support 13, a belt shell 14 provided on the roll support 13, and a load shoe 1.
5, the load shoe 15 is used to load the belt shell 14 against the heatable calender roll 16 to form the extended nip N ₁ . As shown in the figure, the third roll 17 is a so-called soft roll provided together with the soft roll cover 18, especially the polymer cover. In this case, the roll nip N ₂ between the heatable calender roll 16 and the third calender roll 17 is a soft nip. On the other hand, if calendered paper is desired, the third calender roll 17 does not need a soft polymer cover, so that the third calender roll 17 is a hard roll and also the roll nip N _2. It is also a hard nip.

In FIG. 1, the paper web W first advances in the expansion nip N ₁ of the calendar unit 10 while being guided by the wide roll 20. The paper web W advances from the expansion nip N ₁ into the roll nip N ₂ using the take-out roll 21 and the wide roll 22. In the figure, the paper web W advances from the second nip of the first calendar unit 10, for example, the roll nip N ₂ to the second calendar unit 110 of the calendar by using the guide rolls and the linear rolls 23 to 27. When the paper web W needs to be calendered on only one side, the paper web W does not of course go to the second calender unit 110, but after the second nip, for example the roll nip N ₂ of the first calender unit 10. , Go directly to further processing, eg winding.

As mentioned above, the calendar shown in FIG. 1 also includes a second calendar unit 110 having a structure and operation similar to that of the first calendar unit 10. Thus, in FIG. 1, the second calender frame is numbered 111, the extended nip rolls mounted in the frame are numbered 112, the heatable rolls are numbered 116, and the third calender rolls are numbered 116. 117 is attached. Similar to the first calendar unit 10, the expansion nip roll 112 in the second calendar unit 110 also includes a roll support 113, a belt shell 114 on the roll support 113, and a load shoe 1.
15 and a load shoe 115 is used to heat the first calender roll 116 to form a first nip of the second calender unit 110, eg, an expansion nip N _3.
Then, the load of the belt shell 114 is applied. Furthermore, similar to the first calender unit 10, the third roll 17 forms with the heatable calender roll 116 a second nip of the calender unit, eg roll nip N ₄ . Also in this calender unit, the third calender roll 117 may be a soft roll cover, in particular a soft face roll provided with a polymer cover, or alternatively a hard roll may be used depending on the treatment. As shown in FIG. 1, the paper web W is guided by the guide rolls and the linear rolls as described above, similarly to the guide rolls 119 and the wide rolls 120, and the first web of the first calendar unit 10 to the first calendar unit 110. It passes through a nip, for example the expansion nip N ₃ . In the example of FIG.
The paper web W, using a take-out roll 121 and the wide roll 122 advances from the extended nip _{N 3} second nip of the calender unit, for example, the roll nip _{N 4.} The paper web W proceeds from the roll nip N ₄ to further processing, for example winding.

In the embodiment shown in FIG. 1, the paper web is thus calendered on both sides first by the expansion nips N ₁ , N ₃ and then by the roll nips N ₂ , N ₄ , said roll nips being soft or hard nips. It may be either. Furthermore, as mentioned above, the use of the extended nips N ₁ , N ₃ makes it possible, for example, to obtain a large amount of bulk savings compared to traditional supercalendering and to provide sufficient gloss to the roll nip. The calendaring effect can be enhanced by N ₂ and N ₄ . Caliper profiling of paper webs is accomplished by means of roll nips. The calendering can be obtained first by means of roll nip N ₂ , N ₄ , and if necessary by means of extension nip N ₁ , N ₃ . At this point, the progress of the paper web W is in the direction opposite to the direction shown in the figure.

In the calender shown in FIGS. 2 and 3, calendering is carried out by the roll nip in the first stage and then by the expansion nip. In the arrangement shown in FIGS. 2 and 3, as also shown in FIG. 1, the paper web W is calendered on both sides. For this reason, the calendars shown in FIGS. 2 and 3 have two calendar units arranged alternately and are numbered 30 and 130. Thus, one side of the paper web W is calendered by the first calender unit 30 and the opposite side of the web is calendered by the second calender unit. However, the figure
As in case 1, it is possible in this embodiment to calender only one side with only one calender 30 or 130 required for calendering. 2 and 3 are different from each other so that the calendering starts from which side of the web W, and thus the structure of the calender has been described with respect to the difference between FIG. 2 and FIG. Listed only in relation to.

Thus, in the embodiment of FIG. 2, the calendar includes two calendar units 30, 130, which are arranged alternately, both of which are extended nip rolls 32, 132 and, for example, heat rolls 36, 136. Includes a heatable roll and a third calender roll 37, 137 provided in a calendar frame 31, 131 forming a stack, said roll forming mutually a nip N ₁ , N ₂ and N ₃ , N ₄ . To do. The roll nip N ₂ is formed between the heat rolls 36 and 136 and the third calendar rolls 37 and 137, and similarly, the expansion nips N ₁ and N ₃ are connected to the expansion nip rolls 32 and 132 and the heat rolls 36 and 136, respectively. Formed during. As shown in FIG. 2, the arrangement of rolls is advantageously such that the third calendar rolls 37, 137 are at the top and the thermo rolls 36,
Reference numeral 136 denotes a central roll of the calendar unit, which includes the expansion nip rolls 32 and 132.
Acts as a bottom roll. Most advantageously, the third calendar roll 37, 13
7. For example, the top roll is a deviation compensating roll, and the caliper profile of the paper is corrected by the upper nip N ₂ , N ₄ means. Further, in the arrangement shown, the rolls 32, 36, 37; 132, 136, 137 are in the same nip plane and the top rolls 37, 137 and the extended nip rolls 32, 132 are located on opposite sides of the heat roll. And the centrally located thermal rolls 36, 136 are simultaneously supported by the upper nips N ₂ , N ₄ and are extended to the problematic thermal rolls 36, 136 by the expansion nip rolls 32, 132 located at the lowest height. High linear load can be applied. Advantageously, the top roll or third calender roll 37, 137 is provided with a soft roll cover as described with reference to FIG. However, a hard roll may be used as the top roll if desired.

The rolls 32, 36, 37; 132, 136, 137 are provided in both calender units 30, 130 in the support of the bearing housing and are attached to each other by means of long mounting bolts 58, 158 and nip. The forces are not transferred mainly to the frame structures 31, 131 and the base of the calendar, all outside the bearing housing. In FIG. 2, for example, bearing housings of the top rolls such as the third calendar rolls 37 and 137 are numbered 37a and 137a, and bearing housings of the thermal rolls 36 and 136 are numbered 36a and 136a. The bearing housings of the extended nip rolls 32, 132 are numbered 32a, 33; 132a, 133. As described above, the bearing housings of the extended nip rolls 32 and 132 are the outer housings 32a and 132a and the inner housings 33 and 133 that are inside the outer housings 32a and 132a and are movably fitted in the outer housings.
Including one part. Usually, during this type of calendar arrangement, the heat rolls 36, 136 are
It is necessary to use a high temperature, which is large because of sufficient heat transfer capacity, and the load non-uniform surface may be large. With the extended nip rolls 32 and 132, it is possible to apply a load of about 400 kN / m, which is higher than that of the top roll. Structure shown,
That is, the extended nip rolls 32, 132 in the bottom position in the calendar are primarily for safety reasons, but from an operational perspective, the extended nip rolls can be used in a higher position.

As shown in FIGS. 2 and 3, the paper web W includes a top roll 37 and a heat roll 36.
First, the nip N ₂ above the first calendar unit 30 formed between the _two is advanced. The upper nip N ₂ is a roll nip. As shown in FIG. 2, the paper web W advances through the roll nip N ₂ as guided by the guide roll 40 and the wide roll 41, with the upper surface of the web initially positioned relative to the hot roll 36. The paper web W advances to the expansion nip N ₁ by means of the take-out roll 42 and the wide roll 43. The paper web W advances from the expansion nip N ₁ of the first calender unit 30 to the second calender unit 130, and the wide roll 1
Guided by 41, it advances to the roll nip N ₄ formed between the top roll 137 and the heat roll 136. As shown in FIG. 2, the second calendar unit 1
One side of the web W with respect to the heat roll 136 inside the first calendar unit 30
On one side of the web W for the hot roll. Web W has guide rolls 14
2 and the wide roll 143, the upper nip N ₄ further advances to the expansion nip N ₃ provided between the heat roll 136 and the wide nip roll 132. Finally, the web W is taken out from the expansion nip N ₃ and the guide roll 1
Proceed further while being guided by 44 and 145.

In FIG. 3, in the embodiment, the web W passes through the upper nip N ₂ between the top roll 37 and the heat roll 36 in the first calendar unit 30 while being guided by the wide roll 41, The bottom surface of the web W differs from FIG. 2 only in that it is initially positioned with respect to the thermo roll 36. The paper web W has a take-out roll 42.
And from the upper nip N ₂ which is a roll nip by the wide roll 43 to the expansion nip N ₁ formed by the heat roll 36 and the expansion nip roll 32, the paper web W is further moved by the take-out roll 44 and the guide rolls 45, 46. Proceed from the expansion nip N ₁ to the second calendar unit 130. In the second calender unit 130, the web W advances to the expansion nip N ₃ between the heat roll 136 and the expansion nip roll 132 by the wide roll 141, and further, the heat roll 136 and the wide roll 143 are formed by means of the take-out roll 142 and the wide roll 143. The roll nip N ₄ between the top rolls 137 is advanced to the take-out roll or the guide roll 14.
The process of 4 proceeds to further processing.

The upper nips N ₂ and N ₄ are loaded by the movement of the shells of the top rolls 37 and 137, and the nips can be independently opened by the movement of the shells.
The lower nips, that is, the expansion nips N ₁ and N ₃ are bottom rolls (expansion nip rolls 3).
2, 132) is loaded by the movement of unillustrated load elements and the somewhat larger opening of the nip required by the expanding nip rolls 32, 132 of today's construction is fitted inside the outer housing 32a, 132a. The expansion nip rolls 32, 132 are provided by the cylinders 54, 154 so that the expansion nip rolls 32, 132 are
, 136 of the bearing housings 36a, 136a are lifted from the inner housings 33, 133 (support). The lifting operation is performed by the outer casing 32a, 13 of the extended nip roll.
Guided by guide parts 51, 151 fitted in 2a, guide pins 59, 1
Similar to the case of 59, it is arranged between the outer casing and the inner casing. The outer casings 32a and 132a of the bearing casings of the extended nip rolls 32 and 132 are the horizontal cylinders 53,
Similar to 153, it is compatible with moveable support components 52, 152. When the inner casings 33, 133 of the expansion nip rolls and the bearing casings 36a, 136a of the heat rolls come into contact with each other, the supporting parts 52, 152 are pushed below the inner casings 33, 133 by the horizontal cylinders 53, 153, The housing is lowered to rest on the support and the lower cylinders 54, 154 are unloaded and only the weight of the extended nip roll.
When the expansion nip roll is lowered and the inner casings 33 and 133 are placed on the support parts 52 and 152, a small gap (on the order of about 1 mm) is formed between the inner casing and the heat roller bearing casing 3.
It remains between 6a and 136a. However, since the expansion nips N ₁ and N ₃ proceed only with a high linear load as described above, such a gap is not a problem from the viewpoint of operation. The belt shells 34, 134 of the extended nip rolls 32, 132 can be replaced without removing the rolls from the machine. Belt shells 34, 1
In order to replace 34, the inner casings 33, 133 are at a lower position, and there is a gap between the inner casing and the outer casings 32a, 132a, and the belt shell 3
4,134 can be replaced. Guide members 51, 15 for replacement
Only one must be separated. The situation where the inner housing is in the lower, lower position is shown in FIG.

Replacement of the entire extended nip roll 32 is accomplished in the following manner, shown in FIG. The extended nip roll 32 is lowered to a lower position for roll replacement. The long mounting bolts 58 are loosened and turned into the plane shown in FIG. The top roll 37 is lifted by about 200 mm, and in the raised position,
The bearing housing 37a of the top roll is firmly fastened to the side pillar of the calendar frame 31, and the top roll is hung from the bearing housing 37a by the support of the side pillar. The central roll or heat roll 36 is lifted, for example, about half the lift distance of the top roll 37 (eg, about 100 mm), and the heat roll is fastened from the bearing housing 36a to the side posts of the calendar frame.

In the calender frame 31, below the outer housing 32a in the bearing arrangement of the expansion nip roll 32, there is a lifting cylinder 55, which raises the outer housing in relation to the frame. In a normal operating position, there is a wedge (not shown) between the outer casing 32a and the frame 31, and the outer casing is directed onto the frame 31 by the support of the wedge. Within the calendar frame 31, there is a rail 57 extending in the axial direction of the roll, an outer housing 32a is provided with rotating wheels 56, which raises the rotating disk 56 when the calendar is in the operating position. It is not related to the carrying load. For roll replacement,
The outer housing 32a is lifted by the lifting cylinder 55 to lift the wedge support. The rotating disc 56 provided in the outer housing 32a is locked in a lower position by providing an intermediate part (not shown) on the rotating disc, and thereafter, the lifting cylinder 55 enables a lower movement, and as a result. The rotating disk 56 of the outer housing is placed on the rail 57, and the outer housing is oriented to the rotating disk 56 on the support of the rail 57. The roll 32 can then be pulled out along the rail 57. The roll can be lifted by a hall crane so that the outer housing remains on the rail and the inner housing goes out with the roll. Proper mounting of the rolls is done in reverse order.

The top roll 37 of the calendar unit 30 is directly replaced on the upper side by a hole crane. The central roll, or hot roll 36, is directly superseded by the whole crane after the top roll 37 is first removed.

The present invention has been described above with reference to the drawings with reference to the drawings. However, the present invention is not limited to the example shown in the drawings, and may be variously modified within the scope of the present invention.

[Brief description of drawings]

1 is an overall schematic side view of an embodiment of a calendar of the present invention, particularly for two-sided calendering.

[Fig. 2]   FIG. 6 is a schematic side view of another embodiment of a calendar for two-sided calendaring.

3 shows the calendar of FIG. 2 in which the advancement of the web is pivoted such that the side of the web opposite that shown in FIG. 2 is first calendered.

FIG. 4 shows one calender unit of the calender shown in FIGS. 2 and 3 with the nip opened for replacement of the extended nip rolls.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE, TR), OA (BF , BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, G M, KE, LS, MW, MZ, SD, SL, SZ, TZ , UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, B Z, CA, CH, CN, CR, CU, CZ, DE, DK , DM, DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, J P, KE, KG, KP, KR, KZ, LC, LK, LR , LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NO, NZ, PL, PT, R O, RU, SD, SE, SG, SI, SK, SL, TJ , TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW (72) Inventor Carracker, Heikki             Finland, 05400 Yokera Erate             Ye 10 (72) Inventor Teastra, Ville             Finland, 00550 Helsinki             Rio Ninkatu 6 Sae 48 (72) Inventor Paronen and Seppo             Finland, 05400 Yokera Lepis             Tontier 3 F-term (reference) 4L055 CF42 CH02 FA12 FA14 FA15

Claims (19)

[Claims] 1. A first calendering nip (N ₁ ; N ₃ ) with a heatable calender roll (16, 116; 36, 136) and an extended nip roll (12, 112).
32, 132), said nip being an expanded nip and guided through said nip so that the paper web (W) proceeds on at least one side to calender the paper. One calendar unit (10,
110; 30, 130) in a method of calendering paper with a calendar including
Within the calendar unit (10, 110; 30, 130), the heatable calender rolls (16, 116; 36, 136) and the third calender roll (17,
117; 37,137) a second calendering nip _(N 2 with; _{N 4)} is formed, the nip is a roll nip, the paper web (W), the roll nip _(N 2; guided through _{N 4)} As a result, both sides of the paper web (W) come into contact with the heatable calender rolls (16, 116; 36, 136) in both calendering nips (N ₁ , N ₃ ; N ₂ , N ₄ ). How to characterize. 2. The second calendering nip (N ₂ ; N ₄ ) is opposite the heatable calender roll (16, 11) as opposed to the expanded nip (N ₁ , N ₃ ).
6; 36, 136) formed on one side. 3. The second calendering nip (N ₂ ; N ₄ ) together with the heatable calender roll (16, 116; 36, 136) provides a deviation compensating roll (N).
17. 117; 37, 137). 4. The second calendering nip (N ₂ ; N ₄ ) is provided with a calender roll (17; 117) arranged with a soft roll cover (18; 118) and the heatable calender roll (16, 117). 116; 36, 136) such that the second calendering nip (N ₂ ; N ₄ ) is a soft nip. 5. The second calendering nip (N ₂ ; N ₄ ) comprises a hard calender roll (17, 117; 37, 137) and a heatable calender roll (16, 116; 36, 136). Method according to claim 1, characterized in that the second calendering nip (N ₂ ; N ₄ ) formed in between is a hard nip. 6. The paper web (W) comprises a calendar unit (10, 110:
30, 130) is first calendered by a first calendering nip (N ₁ ; N ₃ ) such as an expansion nip, and then a second calendering nip (N ₂ ; N ₂ ) such as a roll nip. ₄ ) and the paper web (W) is calendered by the calender rolls (16, 1) between calendering nips.
16; 36, 136) withdrawn from contact with the surface. 7. The paper web (W) comprises a calendar unit (10, 110:
30, 130) a second calendering nip (N, eg roll nip) _Two ; N_Four) First calendered and then, for example, in an expansion nip
First calendar hanging nip (N₁; N_Three) Is calendared by
The paper web (W) is heated by a calender roll (16,
116; 36, 136) withdrawn from contact with the surface.
Item 6. A method according to any one of Items 1 to 5. 8. A calender profiling of said paper web (W) in a calender unit (10, 110: 30, 130) is carried out by means of roll nips (N ₂ ; N ₄ ). 7. The method according to any one of 7. 9. In a calender, the paper web (W) passes through two successive calender units (10, 110; 30, 130) between which the paper web (W) is
W) changes direction and in a continuous calendar unit, for calendering both sides of the paper web (W), calender rolls () capable of heating different sides of the paper web (W).
16, 116; 36, 136). 10. A calender frame (11, 111; 31, 131), a heatable calender roll (16, 116; 36, 136) and an extended nip roll (12, 112; 32, 132) provided in the frame. ) And at least one calendering unit (10, 110; 30, 130), wherein the rolls form a _first calendering nip (N ₁ ; N ₃ ) which is an expanding nip with respect to each other and through which the paper In the calendar where the web (W) is guided to proceed to calender at least one side of the paper, the third calender roll (17, 117; 37)
, 137) is mounted in a calender unit (10, 110; 30, 130), said roll together with a heatable calender roll (16, 116; 36, 136) being the second calendering nip (N _2). ; N ₄ ), and the paper web (W) is guided to travel through said roll nips (N ₂ ; N ₄ ), so that both calendering nips (N ₁ , N ₃ ; N ₂ , N 4 ₄ ) The same side of the paper web (W) can be heated in the calendar rolls (16, 116; 36, 136).
) Contacting a calendar. 11. A third calender roll (17, 117; 37, 137) is of a heatable calender roll (16, 116; 36, 136) opposite the expanding nip roll (12, 112; 32, 132). The calendar according to claim 10, wherein the calendar is mounted on a surface. 12. A calendar as claimed in claim 10, characterized in that the third calendar roll (17, 117; 37, 137) is a deviation compensation roll. 13. A third calender roll (17, 117; 37, 137) is provided together with a soft roll cover (18: 118) to provide the third calender roll (1).
7, 117; 37, 137) and heatable calender rolls (16, 116; 36)
Calender according to claim 10, characterized in that the calendering nip (N ₂ ; N ₄ ) between (136) is a soft nip. 14. A calender according to claim 13, characterized in that the roll cover (18: 118) of the third calender roll (17, 117; 37, 137) is a polymer cover. 15. The third calender roll (17, 117; 37, 137) is a hard surface calender roll, and the third calender roll (17, 117; 37, 1).
A calender according to claim 10, characterized in that the calendering nip (N ₂ ; N ₄ ) between 37) and the heatable calender roll (16, 116; 36, 136) is a hard nip. 16. In the calender unit (10, 110; 30, 130), the paper web (W) advances first in a first calendering nip (N ₁ ; N ₃ ) such as an expansion nip. And then heatable calender rolls (16, 1
16; 36,136) taken out of contact with the surface and then arranged to proceed into a _second calendering nip (N ₂ ; N ₄ ) such as a roll nip. The calendar according to any one of claims 10 to 15. 17. In the calendar unit (10, 110; 30, 130), the paper web (W) first advances in a _second calendering nip (N ₂ ; N ₄ ) such as a roll nip. , Then heatable calender roll (16,
116; 36, 136) taken out of contact with the surface and then arranged to proceed into a _first calendering nip (N ₁ ; N ₃ ) such as an expansion nip. The calendar according to any one of claims 10 to 15. 18. The calender unit (10, 110; 30, 130) is provided with means for performing caliper profiling of a paper web (W) with a roll nip (N ₂ ; N ₄ ). A calendar according to any one of 1 to 17. 19. The calendar comprises two consecutive calendar units (10).
, 110; 30, 130), and the paper web (W) passes through the unit in a reversing direction so that different sides of the paper web (W) can be used to calendar two sides of the paper web (W). Heatable calendar rolls (16,116; 36,136
) Is in contact with the calendar according to any one of claims 10 to 18.