Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H23/00—Registering, tensioning, smoothing or guiding webs
  • B65H23/02—Registering, tensioning, smoothing or guiding webs transversely
  • B65H23/022—Registering, tensioning, smoothing or guiding webs transversely by tentering devices
  • B65H23/025—Registering, tensioning, smoothing or guiding webs transversely by tentering devices by rollers
  • B65H23/0251—Registering, tensioning, smoothing or guiding webs transversely by tentering devices by rollers with a straight axis
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F7/00—Other details of machines for making continuous webs of paper
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G1/00—Calenders; Smoothing apparatus
  • D21G1/0066—Calenders; Smoothing apparatus using a special calendering belt
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2301/00—Handling processes for sheets or webs
  • B65H2301/50—Auxiliary process performed during handling process
  • B65H2301/51—Modifying a characteristic of handled material
  • B65H2301/514—Modifying physical properties
  • B65H2301/5143—Warming
  • B65H2301/51432—Applying heat and pressure

Definitions

• the present invention relates to a method for controlling a tension profile of a web, like a paper or board web, and web tension profile control apparatus. Further, the present invention relates to a method for manufacturing a web including such a method for controlling a tension profile of a web and web manufacturing machine including such a web tension profile control apparatus.
• a tension profile measuring roll wherein a web tension profile is measured by means of a spiral inclined pressure sensor film which contacts the web at an inclination (WO 2006/075055A1) .
• a measuring roll is distributed under the name iRoll.
• the present invention provides a method for controlling a tension profile of a web comprising the steps heating and pressure treating the web so as to plasticize the web, measuring the tension profile of the web, and profiled treatment of the web in accordance with the measured tension profile of the web in the width direction of the web using heat treatment or mechanical force.
• Plasticizing the web means a plastication of the fibers of the web so as to enable a plastical deformation of the fibers .
• Profiled treatment of the web in the width direction means an unequal or varied treatment of the web in the web cross direction perpendicular to the web conveying direction and perpendicular to the web thickness direction.
• the amount of unequal or varied treatment depends on the measured tension profile .
• a varied amount of heat is applied to the web in the web cross direction in accordance with the varied amount of the measured tension profile.
• the measured tension profile is equal or constant, that is unvaried, in the web cross direction
• an equal amount of heat is applied to the web or no heat is applied to the web.
• a slack portion of the web that is an area with a low tension
• the tension of a tight portion of the web is reduced by the use of a lower
• Profiled treatment of the web using heat treatment can be profiled heat treating the web.
• step profiled heat treating the web can be performed in the heating step.
• the web is treated by means of heat in a profiled manner.
• step profiled heat treating the web can be performed after the heating step, for example, by applying additional heat to respective portions of the web or by appropriately cooling respective portions of the web.
• profiled heat treating the web can include heating as well as cooling respective portions of the web in the width direction of the web for obtaining a target temperature profile of the web in the width direction.
• a varied mechanical force is applied to the web in accordance with the measured tension profile.
• the mechanical force is provided to be at least in part directed in the web cross direction.
• different mechanical forces in the web cross direction are applied in accordance with the different amount of tension at the respective position. Accordingly, in order to reduce slack portions of the web, the slack portions of the web are tightened more using a mechanical force pulling in the width direction of the web.
• Profiled treatment of the web using a mechanical force can be profiled spreading the web.
• slack edges of the web can be tensioned and obliqueness of the web can be compensated away.
• the web can be a paper web or a board web.
• the present inventors found that a plastication of fibers of a web by means of heat and pressure enables easily affecting the tension of the web and, thus the tension profile of the web without any use of moisture.
• the present invention may also provide a control to receive a curved target tension profile.
• the actual tension profile can be adjusted to any target tension profile.
• the method for controlling a tension profile according to the present invention can be executed without any use of a moistening/dampening means.
• the method is simplified and can be employed easily in existing web manufacturing processes.
• this method can be additionally used by merely modifying the dry end of the board manufacturing process.
• the profiled treatment of the web in accordance with the measured tension profile can be performed
• the profiled treatment of the web can be conducted in sections that is stepwise / gradually.
• the steps heating and pressure treating can be performed simultaneously. That is, the steps heating and pressure treating of the web are conducted substantially at the same time.
• heating and pressure treating can be shifted with respect to each other in the web conveying direction.
• one of heating and pressure treating could include a longer dwell time.
• heating and pressure treating of the web are conducted in an overlapping manner in this case.
• the step heating can be performed immediately before the step pressure treating, that is sufficiently close to the pressure treating step, so that the web is still
• the method can be implemented in an existing web manufacturing process comprising an appropriate pressure treating step like a calendering step, so that only a heating step and a profiled treatment step have to be added.
• the method can be implemented in an existing web manufacturing process, wherein the web still has an appropriate temperature, so that only a pressure treating step and a profiled treatment step have to be added.
• the web can be preheated before the pressure treating step and can be heated supplementary during the pressure treating step.
• the step measuring the tension profile can be performed downstream of the profiled treatment of the web.
• control of the tension profile of the web can be performed by feedback-controlling the tension profile of the web .
• the step measuring the tension profile can be performed upstream, i.e. before, the heating step, the pressure treating step or merely before the profiled treatment of the web.
• the step pressure treating the web can be preferably performed by passing the web through a long treatment zone which may include a long nip.
• the pressure treating using a long treatment zone can be formed by using a heat conductive belt and a counter roll.
• the heat conductive belt can be a metal belt.
• a method using any other long treatment zone may be used.
• a long treatment zone provided between two heat conductive belts can be applied.
• the two heat conductive belts i.e. two endless heat conductive belt loops
• pressurized fluid may be supplied to pressure chambers of the pressing means for obtaining a target nip pressure.
• the pressing means can apply pressure by means of rolls arranged on the inner sides of the heat conductive belt loops.
• the dwell time can be increased by extending the length of the long treatment zone and/or by raising the conveyance speed of the web.
• elements in contact with the web can be subjected to profiled heat treating in the width direction of the web in accordance with the measured tension profile for heating / heat treating the web.
• any of the elements forming the long treatment zone can be subjected to profiled heat treating.
• any of the elements forming the long treatment zone can be subjected to profiled heat treating.
• Profiled heat treating of the elements can mean heating and cooling sections of the elements in accordance with the tension profile, that is in accordance with the intended effect on the tension profile.
• the counter roll mentioned above can be subjected to profiled heat treating in the width direction of the counter roll, that is the width direction of the web, dependent on the measured tension profile.
• sections of the counter roll corresponding to a measured low tension are heated more than sections of the counter roll corresponding to a measured high tension.
• sections of the counter roll corresponding to a measured high tension are heated less than sections of the counter roll corresponding to a measured low tension, or the sections of the counter roll corresponding to a
• the heat conductive belt can be subjected to profiled heat treating in the width direction of the web in accordance with the measured tension profile. Accordingly, the heat conductive belt is heat treated in the width direction of the conductive belt, that is the width
• sections of the heat conductive belt corresponding to a measured low tension of the web are heated more than sections of the heat conductive belt corresponding to a measured high tension of the web.
• both of heat treating the counter roll and heat treating the heat conductive belt can be performed.
• profiled heat treating can be performed by blowing hot air and/or cold air on a surface of the respective elements in accordance with the tension profile. For instance, the lower the measured tension of a section of the web the larger the amount of hot air blown on the outer surface of the corresponding section of the counter roll or the heat conductive belt.
• the respective elements can be heat treated by generating induction current within these elements in accordance with the tension profile, that is in accordance with the intended effect on the tension profile. For instance, the lower the measured tension of the respective portion of the web the larger the amount of induction current generated in the corresponding section of the element.
• the pressure chambers for applying pressure on a metal belt as described above can be partitioned in the web cross direction and can be supplied with pressurized fluid heat treated in accordance with the measured tension profile.
• the profiled treatment is performed after the steps heating and pressure treating by passing the web over a spreader roll and actuating sections of the spreader roll in
• the spreader roll generates a mechanical force pulling the web in the width direction of the web.
• the spreader roll can have several actuators for actuating the sections of the spreader roll in accordance with the measured tension profile. For instance, the lower the measured tension of a section of the web the more the actuator of the corresponding section of the spreader roll is actuated so as to pull the web in the width direction of the web .
• the tension profile can be measured online.
• the present invention provides a method for manufacturing a web comprising the steps drying a web, controlling a tension profile of the web after the drying step in accordance with the method for controlling a tension profile as described above, and passing the web to a further treatment like reeling-up the web after
• a web tension profile control apparatus is provided
• profiled treatment means adapted to treat the web in the width direction of the web in accordance with a measured tension profile by profiled actuation of a profilable heat treating means or profiled actuation of a profilable spreading means.
• a profiled heat treating means is adapted to apply a varied amount of heat to the web in the web cross direction in accordance with the varied amount of the measured tension profile.
• the web heating means and the heat treating means can be provided integral with each other.
• profilable heat treating means can be provided downstream of the web heating means.
• the profilable heat treating means can be adapted to heat as well as to cool respective portions of the web in the width direction of the web for obtaining a target
• the spreading means is adapted to apply a varied amount of a mechanical force to the web in accordance with the measured tension profile.
• the mechanical force is provided to be at least in part directed in the web cross direction.
• the spreading means is adapted to apply at different positions in the web cross direction different mechanical forces in the web cross direction in accordance with the different amount of tension at the respective position.
• profilable heat treating means and profilable spreading means can be provided adapted to control the tension profile of the web.
• the web heating means can be formed integral with the pressure treating means.
• the web heating means can be provided
• the tension profile measuring means is arranged downstream of the profiled treatment means .
• the tension profile control apparatus can be adapted to feedback control the tension profile of the web.
• the pressure treating means may comprise a long treatment zone.
• the long treatment zone can be formed between a heat conductive belt and a counter roll. Further, the long treatment zone can be formed between two heat conductive belts. Also, the long treatment zone may be formed between a shoe roll or soft roll and a counter roll.
• the heat conductive belt can be a metal belt.
• the heat treating means can be adapted to perform profiled heating of elements in contact with the web for profiled heat treating the web.
• the heat treating means can be a profilable hot air-blow device.
• the heat treating means can be a profilable hot air-blow device.
• the heat treating means can be a profilable induction heating device.
• the profiled treatment means can comprise a spreader roll as a spreading means arranged downstream of the heating means and the pressure treating means, and is adapted to actuate the spreader roll in accordance with the measured tension profile.
• the present invention provides a web
• Fig. 1 shows the structure of a web tension profile control apparatus according to a first embodiment of the present invention .
• Fig. 2 shows a structure of a web tension profile control apparatus according to a second embodiment according to the present invention.
• Fig. 3 shows a structure of a web tension profile control apparatus according to a third embodiment according to the present invention.
• Fig. 4 shows a structure of a web tension profile control apparatus according to a fourth embodiment according to the present invention.
• the tension profile control apparatus comprises a metal belt arrangement 5 as a web heating means and pressure treating means including a long nip 6 as a long treatment zone.
• the long nip 6 is formed by an endless metal belt 9 as a heat conductive belt supported by rolls 13 and 15 and a counter roll 11 arranged opposed to the metal belt 9.
• the metal belt 9 is arranged so as to follow at least partly the outer circumference of the counter roll 11.
• the metal belt 9 is arranged on an upper side of a web 1 and the counter roll 11 is arranged on a lower side of the web 1, so that the web 1 is nipped in the long nip 6 between the metal belt 9 and the counter roll 11.
• a profilable induction heating device 3 as a combined heating means and heat treating means according to the present invention is provided opposed to the counter roll 11.
• the profilable induction heating device 3 is adapted to heat the surface layer of the counter roll 11 variably in the width direction of the counter roll 11.
• a tension profile measurement roll 7 as a tension profile measuring means is provided downstream of the long nip 6, being adapted to measure the tension profile in the width direction of the web.
• the first embodiment comprises a controller 8 connected with the tension profile measurement roll 7 as well as with the profilable induction heating device 3.
• the controller 8, the profilable induction heating device 3 and the tension profile measurement roll 7 form a profiled treatment means according to the first embodiment of the present invention.
• the controller 8 receives measurement data from the tension profile measurement roll 7 and is adapted to control the profilable induction heating device 3 in accordance with the measured tension profile.
• the controller 8 effects that the profilable induction heating device 3 heats the surface of the counter roll 11 in the width direction of the counter roll 11 with varied power to approach the actual tension profile of the web to a target tension profile of the web .
• the heated counter roll 11 heats the web 1 in a profiled manner when being pressure treated in contact with the web 1 in the long nip 6.
• the fibers of the web are plasticized in a profiled manner.
• plastication of the fibers of the web is affected by the dwell time of the web 1 in the long nip 6.
• the plastication can be influenced by the web speed and the length of the long nip 6. Further, the amount of heat affects the plastication of the web 1.
• the web 1 is heated in accordance with the tension profile measured by the tension profile measurement roll 7 that is in accordance with the deviation of the actual tension profile measured by the tension profile measurement roll 7 from a target tension profile.
• portions of the web 1 comprising a low tension are heated more - and thus tightened more - than portions of the web 1 comprising a high tension.
• the web tension profile control apparatus can be easily attached to the dry end of an existing paper or board machine previous to reeling-up the web or any other further treatment of the web without the requirement of profiled moistening for controlling the tension profile.
• a web tension profile control apparatus and a corresponding method according to a second embodiment of the present invention are described with reference to Fig. 2.
• the tension profile control apparatus includes a metal belt arrangement 5 formed by an endless metal belt 9 and a counter roll 11 arranged opposed to the metal belt 9.
• the metal belt 9 and the counter roll 11 form a long nip 6 as a long treatment zone.
• the counter roll 11 is adapted to be heated uniformly, so that the counter roll 11 forms a web heating means according to the present invention.
• the metal belt 9 or one or both of the rolls 13 and 15 supporting the metal belt 9 can be heated.
• the tension profile control apparatus comprises a tension profile measurement roll 7 as a tension profile measuring means.
• a spreader roll 17 is provided downstream of the metal belt arrangement 5.
• the spreader roll includes actuators in the width direction thereof in order to spread the web in the width direction by applying a force at least partly in the width direction of the web.
• the spreader roll 17 is composed of several sections in the width direction, wherein the alignment of the rotational axes of the sections can be controlled individually.
• the obliqueness of a tension profile can be straightened by turning the spreader roll 17 or sections of the spreader roll 17 equivalently oblique.
• a controller 8 is provided receiving the
• the controller 8 compares the measured tension profile of the tension profile measurement roll 7 with a target tension profile and controls the spreader roll 17 that is the several sections of the spreader roll 17 in accordance with the deviation of the actual tension profile from the target tension profile.
• the controller 8, the tension profile measurement roll 7 and the spreader roll 17 form a profiled treatment means according to the second embodiment of the present
• controller 8 can be omitted and the spreader roll 17 can be actuated manually.
• a nip roll 19 is provided between the spreader roll and the tension profile measurement roll 7 and the web is guided around the nip roll 19.
• the metal belt arrangement 5 with a heating function provides a sufficient plastication of the web facilitating a permanent change of the tension profile by means of the spreader roll 17.
• the spreader roll 17 applies a force component in the width direction of the web 1 in accordance with the target tension profile of the web to tighten slack portions of the web .
• the web tension profile control apparatus comprises a metal belt calender 50 as a pressure treating means including a long nip 6 as a long treatment zone.
• An endless metal belt 9 as a heat conductive belt is supported by rolls 13, 15 and 23 and a counter roll 11 arranged opposed to the metal belt 9.
• the metal belt 9 is arranged on a lower side of a web 1 and the counter roll 11 is arranged on an upper side of the web 1.
• a pressure roll 21 arranged in contact with an inner side of the metal belt loop is provided for applying additional pressure on the web 1 within the long nip 6.
• the web 1 runs via a guide roll 25 into the long nip 6. Downstream the long nip 6, the web is guided by means of a guide roll 27 to the tension profile measurement roll 7.
• a control of the tension profile of the web is conducted similar to the first embodiment by profiled heating the counter roll 11 being a thermo roll as a combined heating means and heat treating means in accordance with the present invention using a controller 8. Moreover, the metal belt 9 can be subjected to profiled heating using the controller 8.
• the tension profile control apparatus comprises a metal belt arrangement 500.
• a metal belt loop formed by a metal belt 9 and two rolls 13 and 15 as well as a metal belt loop formed by a metal belt 10 and two rolls 14 and 16 are arranged opposed to each other forming a long nip 6 as a long treatment zone.
• Pressure chambers 31 and 32 are provided on the inner side of the metal belts 9 and 10, respectively.
• the pressure chambers 31 and 32 are supplied with pressurized fluid so as to press the metal belts to each other forming an appropriate nip pressure.
• the pressure chambers 31 and 32 form a pressure treating means in accordance with the present invention.
• a profilable heating device is provided integral with the roll 14 as a combined heating means and heat treating means in accordance with the present invention.
• the metal belt 10 can be heated in a profiled manner in the width direction of the web 1.
• a further profilable heating device can be integrated within the roll 13.
• other means for subjecting the metal belts 9 and 10 to profiled heat treating could be implemented.
• measurement roll 7 is provided downstream the metal belt arrangement 500.
• the fourth embodiment comprises a controller 8 connected with the tension profile measurement roll 7 as well as with the profilable heating device of the roll 14.
• the controller 8, the profilable heating device of the roll 14 and the tension profile measurement roll 7 form a profiled treatment means according to the fourth embodiment of the present invention.
• controller 8 controls the profilable heating device based on the

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• 2010
  • 2010-04-26 EP EP10718538A patent/EP2563700A1/de not_active Withdrawn
  • 2010-04-26 WO PCT/EP2010/055516 patent/WO2011134487A1/en active Application Filing

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