Hermann Berstorff Maschinenbau Gmbh

Werner Pawelczyk

Klaus-Dieter Marquardt

Willi Woeckener

Ernst Albrecht

The multi-roll calender for producing a sheet of elastomeric material comprises a calender frame and a series of rolls mounted in the calender frame. The rolls including an intake roll and a series of vertically superimposed rolls, with all adjacent rolls being variably spaced so as to provide variable roll gaps between each adjacent pair of rolls. Means are associated with the rolls for sensing the pressure of the material being calendered in each roll gap and means are provided on opposite ends of certain of the rolls responsive to the sensing means for adjusting the width of each roll gap formed by adjacent rolls to cause the difference between the pressures in said gaps to be as small as is practicable. Means are provided for maintaining the adjusted pressures substantially constant.

Multi-roll calender

A method of controlling a multi-roll calender producing a sheet of synthetic plastics, rubber or other elastomeric material comprising sensing the pressure of material being calendered in roll gaps of the calender, which roll gaps follow one after another in the direction of movement of the sheet; adjusting the width of the two gaps formed with mating rolls on opposite sides of at least some of the rolls to cause the difference between the pressures in the two gaps to be as small as is practicable; and maintaining such pressures substantially constant. The method may include measuring, in per se known manner, the thickness of the finished sheet leaving the calender; controlling the adjustment of the width of the final roll gap in the direction of movement of the sheet in accordance with the thickness measurement; measuring the pressure change in the final roll gap resulting from such adjustment; using the measured pressure change as a control variable for adjustment of the width of the gap preceding said final gap; and repeating this control back to at least the second gap, considered in the direction of movement of the material through the calender, such that adjustment of the gap width and thus change of the pressure in a forward one of the gaps of the calender in the direction of web movement, brings about an adjustment of the preceding gap and thus a change in the rate of supply of material into said forward gap. In a calender on which the method of control can be effected, and in which for each roll of the calender which is adjustable with respect to one or two rolls mating therewith, there is provided a separate adjusting device and for each such separate adjusting device a pressure measuring device is provided.

Method of controlling operation of a multi-roll calender

A multi-roll calender for rubber or synthetic plastics material comprising a pair of rolls mounted at their ends in a calender stand, in which at each of the ends of the pair of rolls, the pair of rolls are rotatably mounted in a bearing block which can be moved to move the pair of rolls together with respect to the calender stand with the gap between the two rolls of the pair rolls maintained constant, one of the rolls of the pair rolls is displaceable relative to the bearing block and to the other roll by having its end engaged in a mounting member which is displaceable in the bearing block, a fixed screw spindle is secured to the mounting member, a rotatable internally threaded sleeve is secured against axial movement in the calender stand and has the fixed screw spindle engagement therein, a drivable worm wheel is rotationally rigidly connected to the internally threaded sleeve, the internally threaded sleeve carries an electromagnetic coupling which can be energised to entrain a spur gear for rotation with the internally threaded sleeve, the spur gear is meshed with two further spur gears each rotationally rigidly connected to a respective further rotatable internally threaded sleeve secured against axial movement in the calender stand and respective screw spindles are secured to the bearing block and are each engaged in a respective one of the further rotatable internally threaded sleeves.

Multi-roll calender for rubber or synthetic plastics materials

Synthetic plastics film manufacturing plant comprising material feed means, preferably in the form of a screw extruder and rolling mill, feeding a sheet material to a multiple roll calender, the multiple roll calender comprising seven rolls comprising four bottom rolls disposed in an L-shape, one of which four bottom rolls provided in the foot of the L, is an input feed roll, and three rolls disposed one above the other with their axes disposed substantially in the same vertical plane, the lowest roll of said three other rolls being disposed in a horizontal juxtaposition and in rolling contact with the topmost roll of said four bottom rolls and on the same side thereof as the input feed roll. Preferably a roll of said four bottom rolls which defines an input feed roll gap with said input feed roll is coupled by links to the roll thereabove to form a first linked roll unit; the uppermost roll of said four bottom rolls and the lowermost roll of said three rolls are coupled together to form a second linked roll unit; and the uppermost roll of said three rolls and the roll therebelow are coupled together to form a third link roll unit; said roll units each being adjustably mounted in a frame of the multiple-roll calender.

Synthetic plastics film manufacturing plant including a multiple-roll

A roll calender, for calendering rubber or synthetic plastics materials and including roll counter bending means and roll oblique positioning means, wherein at least one roll of the calender has journal portions at the ends thereof supported in main support bearings and outer end portions of the journals engaged in spherical bearings, an outer portion of each spherical bearing has each of its two opposite sides rigidly connected to a respective hydraulic cylinder, each hydraulic cylinder has a piston therein with the piston secured to a vertical piston rod, intermediate the ends of the piston rod, such that counter bending of the roll can be effected by pressurisation of the hydraulic cylinders selectively above or below the pistons, and the ends of the piston rod are engaged in respective grooves in respective fixed support members such that said ends are movable horizontally in said grooves in directions substantially perpendicular to the axis of the roll to allow the axis of the roll to be moved into oblique relationship with the axis of a co-operating roll located above or below said roll.

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Hannover, Germany

Werner Pawelczyk