Abstract: Calender having a frame having a roll stack therein and a lower deflection control roll as the lowermost roll of the roll stack. The lower deflection roll has a sleeve supported on a bracket having opposed ends. The lower deflection control roll further has a deflection control device configured to secure the bracket against rotation. The deflection control device is further configured to operate in the direction of a center place of the roll stack. The calender further has a pair of bearing blocks, each bearing block being configured to hold a respective end of the bracket. Each bearing block is adjustable by a respective loading device. The calender further includes a pair of pivoted arms each having a proximal end and a distal end, the proximal end swivelly connected to the frame, and the distal end connected to a respective bearing block.

Abstract: A paper calender has a stack of rolls arranged one above the other. They form an upper stack and a lower stack with a common center roll. Additional center rolls are carried on levers that are capable of pivoting about axes fixed with respect to the frame, and are capable of being placed under load by devices applying force. These devices should be designed to be powerful enough to be capable of compensating for more than the total weight of the associated roll and the parts connected to it. As a result of the various possible settings for the line load, the finishing of the paper can be improved. A method is provided for operating a paper calender having an upper stack of rolls and a lower stack of rolls positioned below the upper stack. Each stack is individually capable of being placed under load by upper and lower force generators.

Abstract: A calender for a sheet material, e.g., paper, having at least two treatment stations through which the sheet material passes in succession. To regulate a desired parameter of the sheet material, each treatment station may include a plurality of adjacently arranged adjustment zones positioned in a row extending across a width of the sheet material. The adjustment zones of one of the treatment stations are positioned to be offset relative to the adjustment zones of the other treatment station by a fraction of a width of the adjustment zones, e.g., one-half the width. The particular arrangement enabling improved correction potential without increasing structural expenditure.

Abstract: A calender includes a roll stack that has two end rolls and at least one intermediary roll, wherein the end rolls each have a deflection compensation device that acts in the direction of the intermediary roll. At least one end roll has an additional deflection compensation device that acts in the direction away from the intermediary roll. On the side of the at least one end roll which is remote from the intermediary roll is disposed a supplementary roll. This calender is able to carry out a matte satination operation without being fixed as to roll-specific pressures, which pressures must be of a precise magnitude so as to compensate for the deflection of the intermediary rolls.

Abstract: A calender is provided for calendering a fibrous web wherein the moisture profile of the web can be controlled. The calender includes a plurality of rolls wherein at least one of the rolls comprises a profiling roll. The profiling roll has a plurality of profiling zones extending in a cross-machine direction to define a profiling nip. The roll is independently expandable in each of the zones, such as by an internal pressurized shoe arrangement, so that the pressure in the profiling nip can be varied in the cross-machine direction. A waterbox is positioned adjacent to the profiling nip and water is carried directly into the profiling nip where at least a portion of the water is transferred to the web such that the moisture profile of the web can be varied in the cross-machine direction by varying the nip pressure in the respective profiling zones.

Abstract: A process and device for satining paper may include guiding a sheet through a roll gap defined by a heated hard roll and a soft roll having with a covering. A paper sheet width of the paper may be less than a width of a cylindrical part of each of the covering and the hard roll. The two rolls may be axially adjusted in relation to each other and in accordance with the paper sheet width. Further, the two rolls are positioned such that a first sheet edge is located adjacent a first end of the cylindrical part of the covering and a second sheet edge is located adjacent a second end of the cylindrical part of the hard roll. That is, the cylindrical parts of the covering and hard roll are positioned to be directly over each other, i.e., beyond the sheet edge, at most by a predetermined permissible edge width.

Abstract: A method for quick-opening a set of rolls in a calender, in particular a supercalender, in which a paper or board web to be calendered is passed through calendering nips formed by a variable-crown top roll, a variable-crown bottom roll and by two or more intermediate rolls arranged between the top and bottom rolls. The rolls are arranged to form a substantially vertical stack of rolls, and the intermediate rolls are supported by the use of hydraulic relief cylinders so as to relieve the nip load produced by the mass of the bearing housings of the intermediate rolls and auxiliary devices associated therewith. During the quick-opening of the set of rolls, the bottom roll of the set of rolls is lowered and the relief pressures in the hydraulic relief cylinders are discharged so as to open the calendering nips.

Abstract: A cross directional caliper control system for a calender. A coarse caliper control mechanism adjusts the pressure over a first range of values. A fine caliper control mechanism adjusts the pressure over a second range of values, where the second range of values is smaller than the first range of values. Sensors sense the dimension of the paper web passing through the calender. A control mechanism coupled to the coarse calender control mechanism, the fine calender mechanism and the sensors controls the caliper across the width of the paper by varying the nip pressure with both the coarse caliper control mechanism and the fine caliper control mechanism to shift the variability of the caliper so that it corresponds to nip pressure adjustments within the second range of values. Bumpless adjustments of the coarse control mechanism are made by making counteracting adjustments to the fine control mechanism.

Abstract: A calender for full and light calendering has rollers disposed one above the other. At least the middle rollers are mounted on bearing blocks, which are supported by levers. The levers are pivotably mounted on respective support blocks. The levers can pivot between an upper stop and a lower stop. A lifting device for the lowest roller moves the lowest roller through a separation stroke between an operating position and a separation position. The lifting device also move the lowest roller through an overstroke between the operating position, through a relief position in which the support blocks are spaced from their respective support elements, into an overstroke position, in which the support blocks of some of the uppermost rollers are lifted to an inactive position to permit the calender to be used for light calendering.

Abstract: A calender for treating a paper web includes a roller stack being loaded with a load on one end. The calender has at least two hard rollers each having a substantially smooth outer surface. The at least two hard rollers each have a device for heating a surface of the roller to a temperature of at least 100.degree. C. The calender also includes at least two soft rollers, wherein each of the at least two soft rollers is disposed adjacent to at least one of the at least two hard rollers to form a working nip therebetween. At least one working nip has a dwell time of the paper web passing through the working nip of at least 0.1 ms. The load on the rollers produces an average compressive stress in the at least one working nip of at least 42 N/mm.sup.2. An arithmetic mean of the numerical value of the surface temperature T, the dwell time t and the compressive stress p in all of the working nips satisfies the following relationship:a target value Zg=1.378-0.00356.multidot.T-(0.00825-5.12.multidot.10.sup.-5 T)p-?0.

Abstract: A calender for the two-sided treatment of a paper web has two similar stacks each of which has at least two soft rollers and two hard rollers. Working nips are formed between each hard and soft roller. The calender has at least one working nip wherein the dwell time (t) is at least 0.1 ms, the surface temperature (T) is at least 100.degree.C., and the load (P) on the stack creates an average compressive stress in the working nip of more than 42 N/mm.sup.2. This provides a calender that is smaller and less expensive to manufacture and operate than super-calenders of the prior art but that also affords excellent finishing results.

Abstract: A calender for treating both sides of a web of paper includes a roller stack. A working nip is formed between the juncture of one hard roller and one soft roller. A changeover nip is formed between the juncture of two soft rollers. The roller stack has eight rollers. The two middle rollers form the changeover nip. One of the middle rollers is a deflection adjustment roller and has an upper support device which can be pressure loaded and a lower support device which also can be pressure loaded. The supporting force that is exerted on the jacket by the upper support device is greater than the supporting force that is exerted by the lower support device.

Abstract: A calender having one stack of rollers has a working nip formed between a hard roller and a soft roller. A changeover nip is formed between adjacent soft rollers. The changeover nip is arranged approximately in the center of the roller stack. The cumulative weight of the rollers is such that the sum of the loads per unit of length of the working nips disposed above the changeover nip is at least 80 percent of the sum of the loads per unit of length of the working nips disposed below the changeover nip.

Abstract: A calender for a web including a calender frame and a stack of rolls mounted on the frame and consisting of four rolls arranged one above the other. In the stack, adjacent rolls placed one above the other are arrangeable in nip-defining relationship with one another so as to calender the web in the nips. The stack of rolls in the calender is composed of three variable-crown rolls, of which rolls the roll mantle of at least one roll is displaceable in relation to its roll axle in the direction of the nip plane by loading devices arranged inside the roll, and one heatable roll arranged between two variable-crown rolls. The rolls are preferably arranged vertically so that the two lowest rolls and the uppermost roll are variable-crown rolls and that the third roll from the bottom of the stack is a heatable roll.

Abstract: A frame structure for calenders in a paper machine in which two vertical legs are horizontally connected to one another. The calender rolls are mounted, one above the other, between the vertical legs so that the upper roller is fixed vertically while the lower roller is able to slide vertically. A loading cylinder is used to move the lower cylinder vertically within the frame. The loading cylinder is mounted on a beam structure which is attached at its ends to the inner walls of the frame legs. The beam structure is shaped so that it is able to flex or pivot relative to the frame's legs so that only vertical forces are transmitted to the frame and transmission of bending moments from the beam structure to the frame structure and the foundation is substantially eliminated.

Abstract: A calender arrangement having vertically-arranged upper, center and lower rollers with matching upper, center and lower carrier-blocks and a suspended spindle, comprises a support element above a bearing-surface on the upper carrier-block. The support-element aids in lifting the suspended spindle and a carrier-nut when raising the upper carrier-block. An insert is placed between a bearing-surface on the upper carrier-block and the support-element, which comprises a horizontal slider seated on the upper carrier-block, which enables a relatively small motor to be used to reset the carrier-nut.

Abstract: A method and device for calendering of a paper or an equivalent web material, in which the web material to be calendered is passed through nips formed by a variable-crown upper roll, a variable-crown lower roll, and by two or more intermediate rolls arranged between the upper and lower rolls. The upper roll, lower roll, and intermediate rolls are arranged as a substantially vertical stack of rolls. As the intermediate rolls, rolls are used in which the form of the natural deflection line produced by their own gravity is substantially equal. The nip load produced by the masses of the intermediate rolls and the auxiliary equipment related to the intermediate rolls is substantially relieved, and almost even completely relieved. An adjustable load is applied to the calendering nips by the variable-crown upper roll or lower roll and/or by an external load applied to the upper or lower roll.

Abstract: A multi-roll calender for treating a web material, of the type which develops a linear force, has at least two rolls stacked one above the other in a press plane. A lower roll is constituted as a sag-compensation roll. The other rolls in the calender stack are all equidistant relative to the sag-compensation roll, i.e., they are supported the same distance away from the two supports of the rolls. One of the outermost rolls (either the top or the bottom roll) is fixed in a stand while all the other rolls are movably mounted. The moveable rolls can be acted upon by support forces acting in the plane of the stack. The support forces and the internal pressure of the sag-compensation roll are adjustable via a control device, e.g., a computer, so that even when the rolls sag, the linear force distribution of the rolls is identical over their width.

Abstract: In a calender or roll frame, apparatus is provided for the vertical adjustment of the rolls which are journalled in bearing housings (2) and also vertically displaceably connected with the roll frame (5) via sliding supports (3) and guides (4). The connection between each sliding support and the roll frame (5) takes place via a threaded spindle (7) with a nut (8) without self-locking and also via a housing (9). The nut (8) has at its inner surface (10) a toothed arrangement (11) and the housing (5) has a further toothed arrangement (13) at its inner surface confronting the toothed end face of the nut. The nut (8) and the housing (9) can be moved relative to one another by a switching piece (14) which determines whether the toothed arrangements are meshed or disengaged. In the disengaged state the rolls can move downwards under their own weight.

Abstract: A multi-roll calender for treating a web material, of the type which develops a linear force, has at least two rolls stacked one above the other in a press plane. A lower roll is constituted as a sag-compensation roll. The other rolls in the calender stack are all equidistant relative to the sag-compensation roll, i.e., they are supported the same distance away from the two supports of the rolls. One of the outermost rolls (either the top or the bottom roll) is fixed in a stand while all the other rolls are movably mounted. The moveable rolls can be acted upon by support forces acting in the plane of the stack. The support forces and the internal pressure of the sag-compensation roll are adjustable via a control device, e.g., a computer, so that even when the rolls sag, the linear force distribution of the rolls is identical over their width.

Abstract: In a calender (1) one or several rollers (2) can be positioned by being raised or lowered jointly with the roller stack disposed therebelow; and vertically displaceable sliding members (3) connected with the roller journals are jointly driven, and are blocked when the roller to be positioned (2) is adjacent the desired working position by way of a separate fixation device (6) supported on the frame (4). In a development of the method the rollers are brought in a desired working position after blocking of the fixation device.

Abstract: An actuator (10a, 10b) for calender rolls (3, 4) in a machine calender connected on-line to a paper machine, wherein the actuator is situated between the calender frame (9) and support arms (11), which adjust the movable calender rolls (3,4), in order to load and unload the nips (N.sub.3, N.sub.2) formed by the calender roll (3, 4) in question and its counter roll (3, 2), and to lock the calender rolls (3, 4) to the top position (3', 4'). The actuator (10a, 10b) is of modular construction and consists of a movable frame (13), which forms the frame of the actuator, and which can be connected to the vertical side (9c) of the claender girders (9) so that the vertical position of the movable frame (13) can be adjusted. The actuator module is equipped with a double acting hydraulic cylinder (12), which is connected between the movable frame (13) and the support arms ( 11) of the calender rolls (3, 4) to load and unload the calender nips and to lift the rolls (3, 4) to the top position.

Abstract: The invention concerns a calender, in particular a supercalender, on whose frame (1) a set of rolls (2) is mounted, which comprises an upper roll (3), a lower roll (4), and several intermediate rolls (5) placed between the upper roll and the lower roll. The rolls (3, 4, 5) are supported on the frame (1) by the intermediate structure of the base parts (34, 47, 54) being vertically displaceable along guides (7) provided in the frame. Of the base parts, at least the base parts (54) of the intermediate rolls can be positioned in the vertical direction by means of lifting spindles (6) provided in the frame (1) and by means of spindle nuts (56) provided on the spindle. The base parts (54) of the intermediate rolls are supported on the lifting spindles (6) being vertically displaceable by means of pressure-medium operated relief devices (57) arranged between the base parts (54) and the spindle nuts (56) to reduce the journal loads on the rolls (5).

Abstract: To reduce vibrations occurring in sets of rolls that are immediately successive along the direction of travel of a web conducted through the nips formed between the roll sets, a process, especially for use in double calendars used to treat paper webs, is disclosed in which the natural frequency of one set of rolls is altered with respect to the natural frequency of the other set of rolls. In this manner, randomly occurring vibrations in the first set of rolls do not produce a resonance excitation of the second set of rolls. A roll apparatus having reduced vibratory tendencies also is disclosed.

Abstract: A method for calendering paper, especially with glassine calendering in a calender which comprises press rolls arranged successively in the paper-advancing direction where, at least between some of the rolls, press nips are formed for passing paper therethrough. Each press nip is preferably formed by a pair of rolls, one of which is hard and the other elastic. Paper is advanced into the calender at an initial moisture X within the range of 12% .ltoreq..times..ltoreq.25%, at least one of the press nips having a calculable line pressure higher than 250 kN/m. In operating conditions, the ratio X/LP between paper moisture X and calculable line pressure LP is maintained in the press nips within predetermined limits in such a manner that the maximum value of ratio X/LP divided by the minimum value of ratio X/LP is .ltoreq.2.15, whereby X refers to the moisture percentage of paper and LP is the line pressure at a particular press nip expressed as a quantity kN/m (kilonewton/meter).

Abstract: Support of a nip relieving device to compensate for overhanging weights at an elevationally displaceable bearing part of an intermediate roll of the calender is effected relative to the stand of the calender by an elevationally displaceable support member. This support member is displaceable by a threaded spindle which is rotatable with a motor and gearing and supported by the stand, to which threaded spindle the support member is individually engageable. The support member is thus individually displaceable to the related bearing part, according to the elevational position thereof, into a desired relative position. According to a preferred embodiment, the components of the nip relieving device are arranged in a bearing sleeve enclosing the threaded spindle and the support member is formed by a nut which is elevationally displaceable by rotation of the threaded spindle.

Abstract: The roll calender containing superimposed rolls is provided with base elements which are vertically adjustable at the roll stand and in which there are pivotably mounted movable substantially lever-shaped elements. The roll bearings of the rolls of the roll calender are located at the ends of the movable substantially lever-shaped elements. Between the base elements and the movable substantially lever-shaped elements there are arranged force-applying elements which serve for compensation of overhanging loads. There are also provided stops against which the movable substantially lever-shaped elements are supported when the roll calender is opened or nip relieved.

Abstract: A roller press has a press roll and at least one pressure roll applying pressure to it. In the end region of each pressure roll, there is an associated positioning cylinder. The positioning cylinders relieve the pressure of the pressure roll against the press roll automatically upon an impermissible increase in the operating pressure in the positioning cylinder. For this purpose, each positioning cylinder has a safety valve which is operated either by the working fluid in the positioning cylinder to the pressure relief condition or by an electrical signal, in different embodiments, to relieve pressure in the positioning cylinder. The safety valves are coupled to each other by a signal line. When one safety valve relieves one positioning cylinder, all of the positioning cylinders are relieved.

Abstract: Between an uppermost roll and a lowermost roll there are arranged intermediate rolls mounted with their axles in levers. These levers extend across the width of the roll stand of the calender and are vertically pivotably suspended at a pivot at the roll stand. Nip relieving devices act upon these levers and are supported at a support defining a support location at the roll stand. Each pivot is arranged at an associated bearing element which is elevationally adjustable and which is located at the rear side of the roll stand remote from the rolls. If the position of the intermediate rolls change in vertical direction, the related bearing elements are correspondingly individually and vertically displaced, so that the levers are brought into an essentially horizontal position at which the axles of the intermediate rolls and the pivots of the related levers are located in each case in a related horizontal plane.

Abstract: A control valve for regulating and maintaining the pressure ratio between two pressures (p.sub.1 and p.sub.2) associated, respectively, with two separate pressure systems at a constant value. In particular, the pressure (p.sub.2), prevailing in hydraulic cylinders which serve to press one press roll against a counter roll in a roll press, is controlled as a function of the pressure (p.sub.1) of the fluid which transfers the contact pressure in a deflection adjusting roll of the roll press. The control valve includes a piston, movably disposed in the housing of the control valve, and provided with a first end face area (A1) at one end thereof and a second end face area (A2) at the opposite end thereof. The end face area (A1) is subjected to the first pressure (p.sub.1) in a first pressure chamber (1a) and the second end face area (A2) is subjected to the second pressure (p.sub.2) in a second pressure chamber (2a).

Abstract: A hydraulic adjustment motor containing a piston-and-cylinder unit is provided at the roll surface of a roll to be moved to position the roll surface relative to another roll surface of a further roll. Each adjustment motor is arranged between the related roll surface to be moved and its related roll stand. A regulation device is arranged between a pressure source, the pressure chamber of the adjustment motor and a hydraulic medium vessel. This regulation device regulates impingement of the pressure chamber with different pressures up to the maximum pressure of the pressure source and regulates the outflow of a selected volume of the hydraulic medium out of the pressure chamber, correlated to the desired lowering of each roll surface, during lowering of the roll surface and for maintaining a residual volume of the hydraulic medium. Consequently, there is provided a defined relative position between the roll surfaces.

Abstract: A calender roll wherein the flexible shell is supported by a row of primary hydrostatic bearing elements serving to transmit first forces toward the nip of such roll with a second roll and wherein the shell is further acted upon by a row of secondary hydrostatic bearing elements which generate second forces opposing the first forces. The rate of fluid flow through the secondary bearing elements is regulated with a view to conform the temperature of the shell along the nip of the two rolls to a preselected pattern. To this end, the compensator of a computer in the fluid pressure regulating unit insures that pressure changes are distributed among the primary and secondary bearing elements with a view to match each change of the first forces by an equal change of the second forces. The temperature of the fluid is regulated only ahead of the regulating unit.

Abstract: A positioning mechanism for four column calender machines is disclosed. The mechanism employs an interconnected piston and cylinder arrangement to permit the rolls to be quickly separated and subsequently automatically repositioned. The rolls are supported on a plate assembly movable on a vertically disposed way mounted on the columns. A lost motion arrangement is provided in the plate assembly so that when a paper break occurs or when it is otherwise desired to separate the rolls quickly, the cylinders are released permitting rapid relative movement between the rolls to prevent damage.

Abstract: A sugar cane mill facility for the extraction with imbibition of sugar from sugar cane.This mill is characterized by the fact that it includes a fourth roller placed in front of the upper roller, against which it presses and, above the inlet roller and mounted on a mobile support, means acting upon the said support in order to flexibly push the fourth roller towards the upper roller, adjustable stops hindering these two rollers from coming together, and a trash plate placed between the fourth roller and the inlet roller integral with the said mobile support. The juices extracted by pressure between the upper roller and the fourth roller can be recycled to the bagasse layer feeding the mill, either with the juices which have passed through this layer, or with the juices extracted by pressure between the upper roller and the inlet and outlet rollers.

Abstract: The lowermost roll of a row of superimposed rolls in the stand of a calender is movable downwardly at a continuously increasing speed through a first distance which suffices to increase the width of clearances between neighboring rolls in the event of breakage of the running web so that the rolls cannot damage each other, and thereupon through a second distance which is at least 50 percent of the first distance. The lowermost roll is braked only during movement through the second distance so that the first distance can be covered, under the action of gravity alone or under the action of gravity plus the action of several double-acting hydraulic cylinders, within a fraction of the time which is required for adequate separation of rolls in a calendar wherein the lowermost roll must be braked during travel through the first distance.

Abstract: A positioning mechanism for calender machines is disclosed. The mechanism employs an interconnected piston and cylinder arrangement whereby the rolls may be separated quickly and subsequently automatically repositioned. When a paper break occurs or when it is otherwise desired to separate the rolls quickly, the cylinders, by means of a lost motion connection, quickly separate the rolls by a specified amount to prevent damage to the apparatus. A hydraulic circuit maintains the spacing required for the lost motion connection and allows for interchanging of rolls of different diameters.

Abstract: Continuously running web material is transferred from a dryer, or the like, to a proximate calender, or the like, along flutter suppressing foils. The web may be calendered in a nip between a rotary calender roll and a reel drum with which a reel core is in nip relation for winding the web on the core. The calender may comprise a single roll or a plurality of rolls. A split torque arrangement is provided for the reel drum and the reel core. Especially useful for handling creped tissue paper web.