Abstract: A calender for surface treatment of material webs, wherein in the event of one sided seizure of an intermediate roller the fixed roller not subject to pressure is adjusted in position at one end such that the asymmetrical linear force profile resulting from the seizure is symmetrically adjusted according to the desired condition in order to optimise processing of the material web.

Abstract: A dewatering device for the web-forming or wet section of a papermaking machine comprises foils arranged transverse to a forming wire, that is to say, extend in the cross-machine direction. Force or powering elements act upon the foils so as to exert a force or pressure upon the forming wire, and thus, bring about dewatering and sheet formation of a layer of fiber stock suspension reposing upon the forming wire. The force elements are constructed and positioned such that additional moments are generated which counteract tilting moments produced by the frictional force present between the foils and the forming wire. In certain arrangements, the force elements also can be interconnected with one another.

Abstract: A twin wire former wherein the forming turbulence of a first forming section is quieted by a main forming roller. Behind the main forming roller, as viewed with respect to a predetermined direction of travel of the forming wires, there is accomplished a further forming of the paper web or sheet from the fiber stock suspension in a second forming section. Due to this arrangement there is possible optimum formation of the paper web or sheet with the use of very little dilution water for the fiber stock suspension. Additionally, due to intensive shear forces present in the second forming section flocks formed in the fiber stock suspension and the paper web or sheet at the region of the main forming roller, can be eliminated so that the structure of the paper web or sheet is made more uniform.

Abstract: Pump-like inlet blading has operatively connected therewith a multi-stage stepped diffusor axially opening into a separation chamber. For the removal of light particles, openings or recesses are provided at the outlet side of an inner cylinder and such merge with withdrawal channels at the inner cylinder. If necessary, there are provided for the heavy particles a collecting groove at least in front of turbine-like outlet blading and from which lead openings, so-called saveall openings towards the outside. These saveall openings are briefly alternatingly opened and closed during operation of the stock suspension cleaner. The fluid stream of the cleaned stock suspension is removed by the turbine-like outlet blading. At least one part of the inner cylinder which delimits the separation chamber is separately rotatable relative to the outer cylinder, so that such inner cylinder part can be rotated at a different rotational speed than the outer cylinder.

Abstract: Heat protection hood for heated rolls (1) in particular for rapidly running rolls (1) in paper machines which are partly surrounded by the heat protection hood. In this arrangement an outer screen (7) is arranged partly around the roll (1) and is concentric to it. The outer screen (7) and a likewise concentrically extending partition screen (4) present between it and the roll (1) form an inner gap (5) and an outer gap (6). Respective deflection zones (9) for the air flow drawn along by the roll (1) in the inner gap (5) adjoin each of the ends of the partition screen (4). Deflecting units (10, 11) are provided there so as to deflect the recirculating air flow around the ends of the partition screen (4). The invention is intended to substantially reduce heat losses through radiation and convection and offers the possibility of influencing the axial temperature profile of the roll (1).

Abstract: The apparatus for the continuous winding of a web, in particular a paper web, onto a motor-driven roll core can also continue to be operated during the change of the roll core. A guiding drum serves as a support for the empty roll core during the change and is used for guiding the web. The guiding drum is continuously maintained at a distance remote from the winding. A pressing roll serves to press the web against the winding, a setting signal for a drive of a roll support carriage being derived from the position of the pressing roll, with the position changing based upon an increase in size of the winding.

Abstract: The calendering occurs in a press nip of a calender with application of pressure, moisture and heat. To achieve a desired surface quality, the surface of the paper or cardboard web which is to be calendered is brought in the press nip to a condition above the glass transition curve of the materials. Prior to expiration of 20 to 60 milliseconds, the surface of the paper web departing from the press nip is subjected to a transition step by virtue of a cooling device first in combination with a change in moisture content to a condition beneath the glass transition point of the material. The cooling can occur during contact of the surface to be cooled with a cooled surface or by direct contact with a cooling, preferably inert gas. After calendering there thus arises a diminished increase in the roughness of the paper web, so that the surface quality obtained in the press nip is predominantly retained. There have been illustrated suitable apparatuses for carrying out the method.

Abstract: A process for manufacturing a slotted hole screen made by mechanically joining a plurality of longitudinal members to a plurality of cross bars reduces joint roughness, burrs and recesses by including a step of covering the joints with a covering material which has a smooth exterior surface. The covering material is liquefied and has sufficient surface tension to form the smooth surface. In an alternative embodiment, the joints in a slotted screen formed by welding a plurality of longitudinal members to a plurality of cross bars are smoothed by selectively remelting the joints to form the smooth exterior.

Abstract: The invention relates to a flotation-deinking-device comprising a flotation vessel and at least one inlet for introducing the suspension into the flotation vessel, the inlet being a staged diffusor (12) in which in a region of the stage transition (26) an air inlet opening (20) is arranged. A turbulence generator (28) without an air supply is arranged upstream of the stage transition (26) as seen in the direction of flow.

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 twin screen paper forming apparatus is provided having upper and lower screens moving in a first direction and wrapping around a portion of a leading forming roller positioned at the beginning of a forming zone where the upper and lower screens converge to form a twin screen. At least one stationary forming element is positioned downstream of the leading forming roller to contact with the lower screen. A water guide element is also located in the region of the forming zone approximately at the start of the forming zone. At least one forming rail contacts the upper screen and a pulp suspension discharge nozzle is positioned, to prevent preliminary draining, upstream of the location where the upper and lower screens converge.

Abstract: A blow extruder for producing hoses made of plastic material has, at the outlet of its nozzle arrangement for producing hoses, a cooling air nozzle ring which encompasses hoses exiting from the nozzle arrangement and to which air is delivered from a blower. An apparatus for cooling air delivered to the cooling air nozzle ring includes a direct evaporator provided with a refrigeration plant and arranged between the blower and the cooling air nozzle ring. The direct evaporator includes a plate fin element and an injection device for a cooling agent and hot air. The cooling apparatus further includes a regulation device for controlling the temperature of the cooling air by controlling operation of the cooling apparatus.

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: The de-watering apparatus for a two-wire paper machine is constructed in such a manner that following the convergence of both wires, firstly, a uniform pressure at a forming roll is exerted on the suspension layer located between the wires. Subsequently, both wires pass de-watering rails which may be located in the upper and/or the lower wire. In this case, an under-pressure is exerted at least at the rails located in the upper wire. At least one further de-watering member then follows before both wires are separated again. The de-watering apparatus can also be used after a preliminary de-watering section, for example an endless wire, and also in the direct vicinity of a head box.

Abstract: Calendering takes place in a calendering zone which operates under pressure with application of temperature and moisture. The desired smoothness is achieved with a correspondingly long dwell time of the material web in a correspondingly long calendering zone in view of the speed of web travel. A web which is still wet is guided between parallel heatable surfaces which are arranged on both sides of the web and face each other through the web and can each be pressed against the web. The surfaces are designed to form and hold a given precise contour of the calendering zone over its full length. One surface is constructed e.g. as a casing of a heated roller and the second surface is constructed as an endless flexible belt which can be pressed in a direction towards the roller casing by means of a concave supporting element. If wished, the web can be calendered on both sides with the method.

Abstract: The vibration device according to the invention includes a compensating device influenced by compensating masses for exciting forces caused by the vibrationary movement, the compensating masses respectively being arranged as partial masses on a hollow shaft, being coaxial with respect to one another, and including a displacing rod in their center by means of which the partial masses of the compensating weights can be displaced in the same manner as the eccentric determining the vibrational movement.

Abstract: Apparatus and process are provided wherein pressure is exerted on a web by at least two rollers. One roller includes a roll shell which is rotatable around a stationary beam, wherein the roll shell is supported against the beam by hydraulic operational support elements on the side of the press, as well as by counterpressure elements exerting pressure in the opposite direction. A particularly rapid and safe opening of the roller device, without damaging the supporting elements or the roll shell because of detached supporting elements, is achieved because the hydraulic pressure medium from the pressure areas of at least part of the operational support elements is routed as directly as possible without detours to the pressure areas of counterpressure elements, such as by a multiple sliding valve located at the beam end.

Abstract: In a controlled deflection roll comprising a roll shell rotatable about a stationary support and braced or supported by support elements at the stationary support, a rotational moment is intentionally exerted at the opposite ends of the roll shell by force-exerting elements. These force-exerting elements extend in axial direction of the controlled deflection roll but are offset in spaced relation with respect to the lengthwise axis of the controlled deflection roll. These force-exerting elements operate in pairs in opposite directions with respect to one another. A lever arm is formed by the distance or spacing between the force-exerting elements and such lever arm exerts a greater rotational moment in the presence of modest space requirements and without deformation of the roll shell.

Abstract: To achieve desired treatment results at both sides of a material web to be calendered, the material web is initially guided through a first nip formed between yieldable elastic surfaces confronting the throughpassing material web. In the first nip there is predominantly applied a relatively high pressure to the material web. Then the material web is guided through a successively arranged second nip formed between practically non-yieldable hard surfaces confronting the throughpassing material web. In the second nip there is applied, apart from pressure, in particular heat to the material web. The treatment result achieved in the first nip, namely the smoothness and glaze values of the treated material web, are augmented at both sides of the material web to achieve desired treatment effects.

Abstract: An extended drainage strip (3) is placed next to the primary sieve (5) of a double-sieve mold. It has a liquid-intake space (2), which is disposed between the part of the surface (4) facing the sieve and the sieve (5). Disposed next to the other sieve (6) is at least one adjustable strip (7) arranged so that it can be placed opposite the intake space (2). Intake space (2) has a cross-sectional size that increases, if necessary, in the direction in which the liquid flows. By pressing the adjustable strip (7) against the intake space (2) of the extended strip (3), the shape of the intake space (2) can be controlled, and the suction or intake of the liquid in the intake space (2) is regulated. One object is to achieve steadily increasing suction in the flow direction. This result assists in preventing undesired pressure surges. The drainage device is simplified and thus easy to monitor. Drainage proceeds carefully, with higher retention of fine particles in the sheet of material between the sieves.