Abstract: A calender for the treatment of a paper web has at least one roller stack made of "hard" and "soft" rollers. The soft rollers have a covering made of a plastic whose recovery, after deformation, is such that the depth of the remaining deformation, after a faulty formation of up to 1 mm thick passes through the working nip is a maximum of 5 percent of the thickness of the faulty formation. In this way, paper characteristics that have previously been obtained using conventional 12-roller calender can be obtained with a lower number of rollers.

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 for webs of paper includes a hard roller having a smooth outer surface. A soft roller is disposed adjacent to the hard roller and forms a roll gap therebetween. The soft roller has a coating made of flexible plastic. The coating includes an inner layer and an outer layer. The inner layer is made of a first plastic material and the outer layer is made of a second plastic material. The outer layer has lesser flexibility and greater hardness than the inner layer. The outer layer has an outer surface having wear properties such that under normal operating conditions the average roughness R.sub.a does not exceed 0.5 .mu.m.

Abstract: An apparatus and method for treating a sheet material (3) with an arrangement of rollers (6, 7), including at least one heated roller (8, 9), which defines at least one roller gap through which the sheet of material is passed and acted upon with pressure and/or elevated temperature. A housing (32) surrounds the roller arrangement (6, 7) and the treatment takes place in an environmental atmosphere, the temperature and/or humidity of which can be adjusted to a specified value. A roll of the sheet material is subjected to pretreatment to provide it with desired temperature and humidity conditions before entering the housing (32).

Abstract: A roll whose bend can be controlled has support elements which are designed as ring elements with an annular pocket and an annular pressure surface. The interior space enclosed by the ring element is connected to an outlet line having an adjustable throttle element. By appropriately adjusting the throttle element, any arbitrary intermediate pressure can be maintained in the interior space. Therefore, a wide adjustment rage for the support force is possible, and needs only a feed line for the pressure medium and an outlet line. In this way, relatively large and relatively small path loads can be processed in the roll gap without a major structural change.

Abstract: A pressing apparatus for web-shaped material, especially for smoothing a paper web, has a pressure gap between a roller and a concave pressure shoe. The pressure shoe is loaded by at least two loading elements, which are displaced in the circumferential direction of the roller, and whose loading forces can be adjusted individually. In this way, any desired pressure-stress profile can be set over the width of the pressure gap. Additionally, the radius of curvature of the concave pressure shoe is variable as a function of the loading forces.

Abstract: A roller arrangement with a deflection compensation roller and a counter roller. The deflection compensation roller has a shell, through which a hydrostatic support device is supported on a carrier. The shell-ends are each supported on a ring bearing which is guided in an action plane and is radially adjustable and can be loaded by a force in the slide direction. The shell-ends can each be loaded by a torque which has an axis perpendicular to the action plane. In this way, the deflection of the shell can be matched to be proportionate to the deflection of the counter roller.

Abstract: A bearing for a heated calendar roll comprises a bearing ring having a first surface. The bearing is rotatable about an axis. A first radially fixed hydrostatic bearing arcuate segment has a first surface which mates with the first surface of the bearing ring. The hydrostatic bearing has at least one bearing pocket. The bearing pocket has a device for permitting hydraulic fluid to flow into the at least one bearing pocket. The hydrostatic bearing is disposed substantially at a circumferential position with respect to the bearing which corresponds to a bearing load from the calendar roll. A second hydrostatic bearing arcuate segment has a first surface which mates with the first surface of the bearing ring. The second hydrostatic bearing has a first radially adjustable bearing pocket. The radially adjustable bearing pocket has a device for permitting hydraulic fluid to flow into the radially adjustable bearing pocket.

Abstract: A controlled deflection roll for use in calenders and like machines has a non-rotatable carrier for a hollow cylindrical shell the end portions of which are rotatable on bearings and the central portion of which surrounds hydraulically operated shell deforming elements. A first hydraulic circuit is provided to supply heated oil to the deforming elements, and a second hydraulic circuit serves to feed lubricant to the bearings. The two circuits are separated from each other by thermal barriers which are installed between the shell and the carrier intermediate the deforming elements and the bearings. Valves and/or flow restrictors are provided in the second circuit to vary the rate of feed of lubricant to and/or the flow of lubricant from the bearings. This renders it possible to establish a desired temperature profile along the full length of the peripheral surface of the shell.

Abstract: The cylindrical internal surfaces of inner races of antifriction bearings between the end portions of a deformable shell and the stationary carrier for the shell in a roll for use in calenders surround with some clearance the adjacent cylindrical external surfaces of the carrier. The magnitude of stresses between the pairs of internal and external surfaces is monitored by several sensors at least some of which have pockets machined into the respective internal and/or external surface. The pockets receive a pressurized hydraulic fluid which leaks along paths defined by the respective pair of surfaces to be collected in a tank. An evaluating system monitors the pressure in the pockets and serves to regulate the pressure of supplied fluid and/or the hydrostatic or other supporting elements between the carrier and the shell.

Abstract: A calendar wherein a bottom roll and a deformable top roll flank one or more intermediate rolls is operated in such a way that the shape of the top roll is caused to conform to that of the adjacent intermediate roll before the nip of the top roll with the adjacent roll is narrowed. At least the top roll is heated to enhance the satinizing effect upon paper webs without unduly affecting the specific volume of treated material. It is further proposed to subject the bottom roll to preliminary deformation and/or to heat the bottom roll and/or one or more intermediate rolls.

Abstract: The operation of a calender or a like machine with at least one pair of rolls which define an elongated nip and wherein at least one of the rolls is a so-called bending compensation roll is regulated by a computer which transmits signals to adjustable pressure regulating valves in conduits serving to admit pressurized fluid to a plurality of actuators (such as hydrostatic bearing elements and hydraulic cylinder and piston units for the bending compensation roll) which can alter the load parameter (such as the line load or the compressive strain) in discrete zones of the nip. The computer has inputs for signals which indicate the temperature in the nip, for signals which indicate the characteristics of the web that is advanced through the nip, and for signals from a memory for a pressure reaction matrix.