The method of control curl and the finishing section of paper machine when the treatment surface sized paper
Technical field
The present invention relates to a kind of method of at the finishing section of paper machine size press coated paper especially fine paper being handled according to claim 1 preamble.The invention still further relates to a kind of method of the preamble according to claim 4.
In addition, the present invention relates to a kind ofly be used for the especially finishing section of the paper machine of fine paper of treatment surface sized paper according to claim 11 preamble.The invention still further relates to a kind of finishing section of the paper machine according to claim 15 preamble.
Background technology
As is known in the art, many cylinder group of paper machine adopt two net tractions and/or single net traction.In the traction of two nets, cylinder group comprises two nets, one of them net from the top another net push breadth from the below and make it cylinder surfaces near heating.Between described drying cylinder row (it typically is level row), paper web be freely not have supporting traction, described traction susceptible to and swinging, and this may cause breadth to rupture, and is especially all the more so when breadth is still moistening relatively, so the intensity of breadth is low.Therefore, recently adopt described single net traction more and more, in single net traction, each is organized drying cylinder and only comprises a dry net, breadth under the support of this dry net by whole group, thereby this dry net is pushed breadth and is made it cylinder surfaces near the heating of drying cylinder, and breadth be held in place the reversing cylinder between described drying cylinder or the outside curve side of roller.Therefore, in single net traction, drying cylinder is arranged on the net ring outside, and reversing cylinder or roller are arranged on described net ring inboard.
In the prior art of so-called normal single-wire draw groups, the drying cylinder of heating is arranged on row, and reversing cylinder is arranged on down row, and these arrange common level and parallel to each other.When hereinafter using term " standard (drying) group " and " commutation (drying) group ", it specifically is meant single net draw groups of above-mentioned many cylinder group.
From prior art, can learn and come dry-web by contactless drying.A kind of contactless drying means is the airborne web drying, about the prior art of this point, and can be with reference to Finnish patent 98944 and 107623.Impingement drying also is non-contact drying, as for the prior art of this point, and for example can be with reference to Finnish patent application 20002429 and Finnish patent 106269.
When by normal single-wire draw groups when drying is carried out to paper in the bottom side of paper, if forwardly all be extended with this asymmetric drying on the whole length of dryer section, then this drying makes that the bottom surface side of paper web is at first dry, along with the progress of drying, this dry effect also is diffused into the upper surface side of paper web.Gan Zao paper has curling test because of this asymmetric drying usually like this.
As is known in the art, by the speed difference between selected weir plate spout and the net and other operational factors influence with form breadth especially page form the curling test of the paper that the stage produces.Yet, in paper machine, especially in the major part of drying section length, have single the net in the fine paper machines of drawing, also must use other device to control the curling test of paper in practice, make dry upwards fully symmetrical at z.
Can know from prior art, carry out drying if paper one side is moistening from one or both sides, perhaps the paper both sides are impartial moistening and carry out drying from a side, and then paper all can curl.Can also know that the air dry-set by being arranged on a side is impingement hood or drying cylinder for example, can control the curling of paper from a side.When a side is carried out drying to paper, paper is dry also to curl to dried side, and this curls and can also control its drying then by the opposite side of the moistening paper of moistening device, thereby paper is flattened.
For above-mentioned purpose, applicant's Finnish patent 98387 discloses different paper ornamenting groups, in particular for the ornamenting group of fine paper.
About prior art, can be with reference to Finnish patent 101987, it discloses a kind of method of surperficial treatment paper especially fine paper being carried out drying.In the method, at first in the forward dryer section of paper machine by plurality of continuous, under the support of single net draw groups at dry net of under shed, paper is carried out drying; Then, paper web is carried out ornamenting, in this finishing section, breadth is carried out top sizing or coating at finishing section.In the method, at finishing section, in the drying group, supply damp-heat air to suppress evaporation at the desired locations of breadth expectation side, perhaps supply heated dry air to promote evaporation, thereby control is curled, and eliminates and/or compensate the curling test that paper web forwardly produces in the dryer section substantially.
About prior art, can be with reference to Finnish patent 105935, it discloses a kind of method of dry paper, this method comprises the following stage: a) paper web to be dried is reached forward dryer section from press section, forwardly in the dryer section, bottom surface side from paper web in the drying group that adopts normal single-wire draw carries out drying to this paper web, and this forward dryer section only comprises single net draw groups of using normal single-wire draw; B) paper web is reached finishing section from this forward dryer section, paper web is coated with/top sizing by coating/top sizing device at this, in the oven dry group portion of rear portion, carry out drying then, in the drying group of at least one employing normal single-wire draw, carry out drying at this paper web, paper web press polish in calendering device afterwards, and reach coil paper portion, be wound at this paper web on the winding up roller of paper machine.In the method, by at least one steam chest in finishing section zone at least paper web is curled and to control, strengthen the effect of described steam chest by cooling breadth before described steam chest, and in the method, the curling of paper web controlled by the combination that the member in finishing section zone at least and/or assembly and described member form.
Can also be about prior art with reference to Finnish patent 101488, it discloses a kind of after-dryer section at paper machine surface-treated paper web or equivalent has been carried out dry method.In the method, paper web at first carries out ornamenting at finishing section, in this finishing section, on both sides paper web is carried out top sizing or coating by the ornamenting device; Afterwards, paper web is carried out drying.In after-dryer section, paper web is dry in only using the drying group of normal single-wire draw, and combines with dry run or after drying, by the device that the curling test to paper web compensates paper web is handled.
Can also be about prior art with reference to Finnish patent 106270, it discloses a kind of after-dryer section at paper machine surface-treated paper web or equivalent has been carried out dry method.In the method, paper web at first carries out ornamenting at finishing section, by the ornamenting device paper web is carried out top sizing or coating in this finishing section, afterwards paper web is carried out drying.In this finishing section, paper web carries out drying in drying group of the single net traction of at least one use, simultaneously, by combining the percussion mechanism that is provided with described dry at least one cylinder organized or roller paper web is carried out drying.
Summary of the invention
One object of the present invention is further to improve above-mentioned device, make can be in after-dryer section than before more effectively control the curling test of paper.
A problem of the known device of prior art is, forwardly use in the dryer section single net traction in the dry group of under shed, the strong curling test of dry paper and consequent stress can not moisteningly by top sizing produced discharge fully, particularly be transformed into when adopting surperficial sizing material with dry solids more all the more so.Even one object of the present invention is to provide a kind of device that still can eliminate the paper web curling test or make paper web curling test minimum at least under such situation.
One object of the present invention is to provide a kind of device that is used for paper especially top sizing fine paper is carried out the method for ornamenting, and it is eliminated with the curling relevant problem of paper or makes with the curling problem of being correlated with of paper minimum.
To achieve these goals and the purpose that occurs later on, principal characteristic features of the method according to the invention is the described content of characteristic as claimed in claim 1.
Principal characteristic features of the method according to the invention is the described content of the characteristic of claim 8.
Be the described content of characteristic of claim 11 according to the principal character of the finishing section of paper machine of the present invention.
In addition, be the described content of characteristic of claim 15 according to the principal character of the finishing section of paper machine of the present invention.
The present invention relates to a kind of paper machine, wherein adopt the drying group under shed of single net traction to be used in the forward dryer section, therefore in paper web, produce curling test; Perhaps in this paper machine, forwardly the end of dryer section also has the drying group that adopts two net tractions, and this moment is in fact littler to the demand of curl control.Forwardly after the dryer section, paper web carries out top sizing; Afterwards, paper web mainly carries out drying by contactless drying in the cylinder group of the rear portion of finishing section---airborne web drying and/or air drying and/or impingement drying and/or infra-red drying.Hereinafter, term " rear portion drying " is meant the drying in the cylinder group of rear portion, that is, make moisture after the top sizing preferably at least 60%, more preferably at least 75% even provide by contactless drying to the evaporation of the water yield the final contained humidity of breadth and the power demand up to 90-100%.
The present invention also is suitable for and also adopts the finishing section of the paper machine of cylinder dried to be used in combination except that adopting contactless drying, but, is undertaken by contactless drying to the small part drying.
In a preferred embodiment of the invention, finish by the airborne web drying to the contactless drying of small part, wherein, place the not adjustable power of the airborne web drying device of homonymy of breadth, thereby can further compensate not releasable stress and residual thus curling test in the top sizing process.The ratio that the airborne web drying accounts for the rear portion drying is at least 60%, preferably at least 70%, even can be up to 90-100%.In conjunction with the present invention, can use the contactless drying that the curling infra-red drying device of controlling is not produced as for contactless drying, for example carry out 10% rear portion drying by the infra-red drying device.About the present invention, also can use the cylinder of heating cylinder as the clamping group, about changing the clamping group, described heating cylinder can be used for controlling curling on the breadth bottom side, perhaps only is used to improve dry power.In this case, in the drying of rear portion the about 10-20% in the dry water can evaporate by the described cylinder of this clamping group.
In another preferred embodiment of the present invention, also can finish to small part rear portion drying based on impingement drying, about impingement drying, preferred use is provided with the percussion mechanism of curl control.In this case, the dry ratio of being finished by impact is at least 50% of a rear portion drying, and is preferred 70%, even up to 90%.Consider then to curl, by determining that percussion mechanism acts on the not size of the part of homonymy of breadth, for example makes its length difference---promptly in after-dryer section to pre-dried paper carries out more top side drying from the bottom side---and the speed of the used air-flow of percussion mechanism and temperature still can be remained in the curl control permissible range.
According to a further advantageous embodiment of the invention, can use the different airborne web dryings and the combination of impingement drying, to set up the contactless after-dryer section that suitable control is curled.
According to a preferred embodiment of the present invention, except the airborne web drying, also adopt the standard cylinder group of single net traction, wherein drying is a contact drying.In this embodiment, breadth preferably at first carries out drying by the airborne web drying, carries out drying by drying cylinder then, carries out drying by the airborne web drying more afterwards.By this device, also can be controlled at the curling test that produces in the forward dryer section at high speed, and be the airborne web of carrying out when dry when last drying from the breadth both sides, produce high moisture gradient will can not resembling fully from a side when dry in the paper web.Dry breadth also provides more adjusting possibilities of control curling test from both sides.
According to a preferred embodiment of the present invention, in the finishing section of paper machine, adopt airborne web drying and impingement drying in the drying of rear portion, and in addition, also adopted the standard cylinder dried of single net traction as contactless drying.In this embodiment, impingement drying preferably is embodied as vertical drying, and after-dryer section is easy to be provided with enough impingement drying length like this.In the preferred embodiment of the present invention, dry the making of airborne web can be from both sides drying breadth, thereby can control curling test by the parameter of adjusting the airborne web drying device, and when carrying out on the not coplanar at breadth when cylinder dried and impingement drying, can be from both sides drying breadth, and, can control curling test by regulating the power that impacts.
The method according to this invention and paper machine can be controlled at the curling test that produces in the forward dryer section that adopts single net traction.
According to the present invention, after-dryer section is used top sizing technology and contactless drying, is that airborne web drying or impingement drying are curling to control to small part wherein.By this device, can eliminate the curling test of breadth.In the present invention, use air or impingement device, it is placed on the breadth both sides, and can adjust the drying device of both sides separately, i.e. the drying of homonymy ratio not, thus make paper web to carry out drying to eliminate the required mode of curling test.Preferably, can use the drying device that dry power is distributed along the breadth transverse copying, thereby can influence curling profile, for example by adjusting along breadth horizontal air blowing speed and/or air blowing temperature.
The spray nozzle device of the airborne web drying device that is used in combination with one embodiment of the present invention is preferably asymmetric with respect to the top side and the bottom side of breadth, thereby make heat exchange asymmetric, can not curl because of control like this causes dry power loss, and considers that the default basic spray nozzle device that curls still leaves whole curl control power for use.Alternatively, in conjunction with the present invention, an adjustable air breadth drying device is for example used in curl control power operation that can also be less.
According to the present invention, in the after-dryer section and nonessential use cylinder dried, but cylinder/roller group might must be set in the after-dryer section to be used as breadth clamping group, to be used to provide and improve the performance of advancing of paper web.Yet even see that from the angle of curling the cylinder of described clamping group is positioned at the wrong side of breadth, but the cylinder of described clamping group also can be used for increasing dry power.Yet the cylinder of dry breadth bottom surface also can be used in the curl control control surplus as opposite side.
In these embodiment of the present invention, in the cylinder group of the rear portion of finishing section, adopt cylinder dried, compare with the contactless drying in the drying of rear portion, can regulate the dry tenacity of contact drying by the power of adjusting dryer cylinder, thereby can also control curling by the cylinder dried parameter.
In a preferred embodiment of the invention, drying in the after-dryer section after top sizing is mainly finished by the airborne web device---and the drying that is realized by the airborne web drying device is at least 60%, being preferably 70%---described airborne web drying device is positioned at the both sides of breadth, like this, when the airborne web drying device that is arranged on the breadth both sides is controlled dry power respectively---when preferably controlling air blowing speed and/or temperature, the asymmetric drying that forwardly produces in the dryer section can obtain correcting.
According to a further advantageous embodiment of the invention, size press coated paper carries out drying by air dry-set, and described air dry-set is positioned at the breadth both sides, and preferably, the temperature of homonymy and air blowing speed are not regulated separately.In the preferred embodiment of the present invention, the both sides drying device that can be adjusted independent of one another by homonymy is not controlled curling, thereby avoids the use and the consequent considerable drying cost of wetting moisture.
According to a preferred illustrative embodiment of the present invention, if desired, aid in curl control in the after-dryer section by steam chest, this steam chest for example can use like this: if paper is straight naturally, then do not use steam chest, because do not need control to curl; If the edge of paper web upsweeps---this is a modal trend after the forward dryer section that adopts single net traction, then uses steam chest; When if the edge of paper web tends to curl, then for example use the drying cylinder of the clamping group of rear portion cylinder group downwards.Steam chest preferably places and is right after the preceding position of winding roll, and is colder than the breadth in dryer section at this breadth, and because drying is mainly undertaken by contactless drying, therefore do not need steam chest that too many drying is provided.
According to a preferred embodiment of the present invention, impingement drying is used for contactless drying, the Finnish patent application 20002429 that associated prior art can the application reference people, and it discloses the device that is used for non-size press coated paper; And applicant's Finnish patent 106269, it discloses the percussion mechanism that acts on to the front/rear portion dryer section, and its application can be used in combination with the present invention.
According to supplementary features of the present invention, impingement drying can be used as a kind of possible control device, wherein impingement device for example combines setting, the suction cylinder type that described suction cylinder is preferably sold with the trade mark of VAC ROLL as the applicant with reversing cylinder or trough of belt deflector roll or suction roll or suction cylinder on market.The impingement device that is used in combination with the present invention also can be so-called vertical percussion mechanism, and its details for example has more detailed description in applicant's Finnish patent application above-mentioned 20002429.
If desired, may the curling of having done slightly to be coated with by size press or other means of paper also can be corrected by the way.Yet, the curl control in the coating usually not necessarily, but when becoming the scumbling cloth that adopts dry solids more, have and must carry out curl control by further press polish slightly (it also has the curl control effect) possibly.In size press coated paper, can also control moving of water in the paper, to reduce since the fiber roughing of paper and adhesive move due to the both sides smoothness of dust.
Description of drawings
Illustrate in greater detail the present invention below with reference to the accompanying drawings, but the present invention does not straitly only limit to its details.
Fig. 1 is the schematic diagram of one embodiment of the invention;
Fig. 2 is the schematic diagram of another embodiment of the present invention;
Fig. 3 is the schematic diagram of another embodiment of the present invention;
Fig. 4 is the schematic diagram of another embodiment of the present invention;
Fig. 5 is the present invention's schematic diagram of another embodiment again;
Fig. 6 is the present invention's schematic diagram of another embodiment again;
Fig. 7 is the present invention's schematic diagram of another embodiment again; And
Fig. 8 is the present invention's schematic diagram of another embodiment again.
The specific embodiment
In Fig. 8, except as otherwise noted, use identical Reference numeral to represent the parts that correspond to each other at Fig. 1.
Fig. 1 is the schematic diagram of one embodiment of the invention, wherein, paper web W passes to top sizing portion 20 from forward dryer section (not shown), carries out top sizing in the nip of paper web W between roller 22,23 on both sides, and the two sides of paper web W are owing to moisture Cypres becomes moistening in this nip.Like this, paper web asymmetricly dry and that be tending towards curling in the dryer section is forwardly handled, made the internal stress of this paper web discharge or weaken at least.Cypres is delivered on the top sizing roller 22,23 from feedway 21,24.Then, paper web W carries out contactless drying; At first by placing 31, the 32 couples of paper web W of airborne web drying device on the paper web both sides to carry out drying.Afterwards, breadth passes through cylinder or roller 33, and by impingement drying its upper surface is carried out drying by the dry gas stream from impingement hood (impingement hood) 34.Be airborne web drying device 35,36 afterwards, further dry to breadth by airborne web drying device 35,36 from both sides.Then, this breadth arrives the clamping group, and this clamping group is made of two cylinder/ rollers 41,42 and comprises net 46, and this net 46 supports advancing of breadth when breadth is advanced on cylinder 42.Combine with this clamping group and to be provided with steam chest 45, be used for further controlling when needed curling test.Rack construction and base are with Reference numeral 10 expressions.
In exemplary embodiment shown in Figure 2, the start-up portion of this embodiment is corresponding with Fig. 1.After clamping group 40, breadth carries out another contactless drying steps by cylinder 43, and the first air paper web drying device 51,52 carries out drying from both sides to breadth in this step.Cylinder or roller 53 are arranged afterwards, and breadth is by cylinder or roller 53, and the impingement drying air communication overbump drying that is produced by impingement hood 54 is carried out drying from upper surface side to it simultaneously.Then, breadth further passes through between airborne web drying device 55,56, from the breadth both sides breadth is carried out drying here, be the second clamping group 60 afterwards, this second clamping group comprises cylinder/roller 61,62 and breadth is supported in net 66 on the cylinder 62, and the steam chest 65 that combines setting with this clamping group, this steam chest can further be controlled by the curling test to breadth in needs.
In embodiment illustrated in figures 1 and 2, airborne web drying device 31,32,35,36,55,56 may be controlled to breadth not the dry power on the homonymy can regulate, like this, can correct the curling test that may remain in after the top sizing in the breadth.If desired, described airborne web drying device can have profiling distribution (profiling), make like this can be for example by breadth air blowing speed and/or temperature and the dry power of its generation is regulated transversely, thereby make the curling profile that can regulate breadth.
If desired, impingement hood 34 also may be embodied as and makes its power at described transversely profiling distribute (beprofiled).Combining the roller or the cylinder 33,53 that are provided with impingement hood can be the structure of drying cylinder formula---dancing roll or suction roll, for example, the suction roll of the inner suction box of nothing that the applicant sells on market with the trade mark of VAC ROLL.
Fig. 3 is the schematic diagram of the paper machine of an embodiment of the present invention.Paper pulp is supplied to breadth forming section F from the head box H of paper machine, forms breadth W and from breadth water is removed at this.At press section P, in nip, from breadth, further remove and anhydrate, then, breadth W is sent to forward dryer section D.The D of this front portion oven dry group portion comprises some drying group G1, G2 under shed and the single net traction of employing ... G6.Forwardly after the dryer section D, breadth W marches to top sizing device 20 through measurement mechanism M; Then, carry out drying by the airborne web drying device 31,32 that is arranged on the breadth both sides from both sides to breadth W, the power of each all can be regulated separately to control curling trend in the described airborne web drying device 31,32.Breadth arrives next airborne web dryer section by roller/cylinder 33, at this, carry out further drying by the airborne web drying device 35,36 that is arranged on the breadth both sides from both sides to breadth, described airborne web drying device can be controlled respectively, so that curling test can be controlled by dry power.If desired, described airborne web drying device 31,32,35,36 can also can influence curling profile like this along laterally the controlling of breadth W.Be clamping group 40 afterwards, its by cylinder or/roller forms and as the clamping group, this clamping group comprises cylinder/ roller 41,42,43,44 and net 46, and the steam chest 45 that combine setting with following row's cylinder/roller 43.Then, breadth press polish in calendering device C, breadth W arrives coil paper device (reel-up) R to be wound into the machine paper bowl afterwards.
Fig. 4 is the schematic diagram of one embodiment of the invention, and it uses so-called vertical percussion mechanism 72,73,74, can reference example such as the applicant's Finnish patent application 20002429 about its further details.Each vertical percussion mechanism 72,73,74 comprises impingement hood 91,92, the machine direction of described impingement hood and approximate horizontal is placed vertically substantially, wherein, breadth W advances at the percussion mechanism 72,74 that is being arranged in above the machine plane under the support of net 95 and be arranged on above the breadth W, and breadth W is advancing in the percussion mechanism 73 below machine plane and breadth W under the support of the net 79 of clamping group.This net traction is by alignment deflector roll 94 and reversing cylinder or roller 93 supports.In the embodiment shown in fig. 4, after the top sizing device 20 is airborne web drying device or infra-red drying device 70, and it carries out drying from both sides to breadth W, thereafter, combine with the clamping group and to be provided with impingement device 72,73,74, this clamping group adopts single net traction.Breadth W arrives first impingement device by commutation suction roll 71 from airborne web drying device or infra-red drying device 70, be the clamping group 79 that adopts single net traction afterwards, this net is by Reference numeral 79 expression, and combines with clamping group 79 and to be provided with an impingement device 73.The cylinder of this clamping group is by Reference numeral 75,76,77 and 78 expressions.After the percussion mechanism 74 of upper back is the clamping group, and the net of this clamping group is by Reference numeral 83 expressions, and the cylinder/roller of this clamping group is by Reference numeral 81,82 expressions.Breadth W arrives first impingement device 72 from described commutation suction roll 71, and at this, breadth carries out drying from upper surface, and by the dry gas stream that impingement hood 91,92 produces it is curled and to control.Afterwards, breadth W reaches so-called lower impact drying device 73, the opposite side of the dry breadth W of this impingement device, its structure also can be controlled curling, be to adopt single clamping group of netting traction afterwards, cylinder is represented by width of cloth figure mark 76,78 by Reference numeral 79 expressions, commutation suction roll by Reference numeral 75,77 expressions, net in this clamping group.Be another so-called vertical impingement device 74 afterwards, its structure example is as corresponding with the first top impingement device 72, and its structure also can be controlled curling, and its air blowing speed and power can be adjusted.Be another group afterwards, it is formed by cylinder 81 and net 83 and the suction roll 82 that commutates, and this group is as the clamping group.In Fig. 4, the suction box 99 that is positioned at breadth transmission position is used for guiding breadth W, and is used to guarantee described transmission.In described clamping group, described cylinder is all last row---and except at the percussion mechanism place, and the commutation suction roll is positioned at row down.
In illustrative examples shown in Figure 5, airborne web drying device and impingement device all are used for controlling curling of breadth W.Breadth W transmits from top sizing device 20, to carry out the airborne web drying by the air dry- set 31,32 that is arranged on the breadth W both sides, preferably, the power of described airborne web drying device can be regulated, and described airborne web drying device preferably can laterally controlling to control curling profile along breadth W.After the airborne web drying is so-called impingement device 72, and at this, breadth W surface from it is dried.The cover of percussion mechanism is with Reference numeral 91,92 expressions, and breadth W advances under the support of net 95 in the impingement drying process.Afterwards, breadth W arrives ensuing impingement device 73, at this opposite side from breadth breadth is carried out drying, and the structure example of this impingement device is as corresponding with said structure.Certainly, the size of described cover and described height of devices can determine as required.The air blowing speed and the power of described percussion mechanism can be controlled.Afterwards, breadth W carries out the airborne web drying, and it is realized by the airborne web drying device 35,36 that is arranged on the described breadth W both sides.Be the clamping group afterwards, its net by Reference numeral 87 expression, on arrange cylinder by Reference numeral 84,86 expression bottoms commutation suction rolls by Reference numeral 85 expressions.
In exemplary embodiment of the present invention shown in Figure 6, breadth W arrives the airborne web drying section from size press portion 20, and described airborne web drying section is formed by the airborne web drying device 31,32 that is arranged on the breadth W both sides.Afterwards, cylinder dried portion 100 is arranged in after-dryer section, it applies cylinder dried, and this cylinder dried portion in the embodiment of the invention shown in Figure 6 comprises the drying groups 101 and 102 of two use normal single-wire draw, and the dry net of described dry group is represented by Reference numeral 103 by Reference numeral 104 expressions, reversing roller/reversing cylinder with Reference numeral 105 expressions, drying cylinder.Be the airborne web drying section that two airborne web drying devices constitute after this cylinder dried portion 100, wherein, breadth carries out drying by the airborne web drying device 35,36,37,38 that is arranged on the breadth W both sides; Be the cylinder group at last, it is as the driving group, and comprises dry net 87, drying cylinder 86 and 84 and reversing cylinder 85.After calendering device C, breadth arrives coil paper device R.In this embodiment of the present invention, the curling test that breadth forwardly produces in the dryer section is mainly controlled by the drying parameter of adjusting the airborne web drying device.Adjust by heating and/or air blowing speed, make it be higher than the corresponding speed of the airborne web drying device of breadth below, can make the upper surface of breadth more dry especially the airborne web drying device on the top side.In addition, can control curling test by the drying parameter of adjusting drying cylinder 10, for example steam regulation pressure to be influencing the surface temperature of cylinder, thereby influence is to the dry ratio of paper bottom side.
In exemplary embodiment of the present invention shown in Figure 7, breadth arrives the airborne web drying section from size press portion (not shown), this airborne web drying section is formed by the airborne web drying device 31,32 that is arranged on the breadth W both sides, be the drying cylinder portion 100 among the embodiment as shown in Figure 6 afterwards, this drying cylinder portion 100 comprises two drying groups 101,102 that adopt normal single-wire draw.Afterwards, breadth arrives vertical impingement drying group 110 by cylinder 107 and 108.The impingement drying cover is by Reference numeral 91,92 and 96 expressions, and wherein drying hood 96 combines setting with reversing cylinder 93, and impingement hood 91,92 is arranged on the roughly vertical course of breadth.The deflector roll of this impingement drying group is by Reference numeral 94 expressions, and the advancing property assembly that the support breadth is advanced is by Reference numeral 105 expressions.After impingement drying, breadth arrives the driving group, and this driving group is formed by cylinder 82 and 84, and breadth is from arriving calendering device C by reversing cylinder 82 here.
The basic element of character of exemplary embodiment of the present shown in Figure 8 is with shown in Figure 7 corresponding, and its difference is that the reversing cylinder VAC ROLL that is arranged on position 88 is replaced by cylinder/deflector roll level and smooth or trough of belt.
In above-mentioned accompanying drawing, if desired, can regulate the air blowing speed and the power of airborne web drying device and impingement device, to realize control, in addition, can also control the transversely moulding that is crimped onto breadth W to curling.
In conjunction with the accompanying drawings, need special consider is, the size of impingement hood and described height of devices are general guide, its size can be determined as required.
Only describe the present invention above, and the present invention does not straitly only limit to its details by reference preferred illustrative embodiment more of the present invention.