EP1088933B1 - Semi-permeable membrane with interconnected pores for a press - Google Patents

Description

The invention relates a uniform membrane for use in a pressing device with in particular several a chamber forming rollers. It also concerns a procedure for producing a corresponding membrane. A method of in the preamble of claim 10 specified type For example, in WO 95 25200 A described (See also EP-A-0 473 969).

There have been attempts for many years, external air pressure to use it to push water out of a paper web. Instead of compressing a sheet at a nip to the point expels water at the hydraulic pressure, as it does in the normal Wet pressing is the case, it was considered that more water removed and sheet volume could be maintained when applying air pressure could be to the hydraulic pressures generated by the nip to support. Such an attempt involves that a Multi-roll structure is provided, which is a closed chamber forms, with air being circulated through the chamber, to transport moisture out of the paper web.

The provision of an effective seal of a multi-roll chamber can be problematic. It is known to form a roller assembly, wherein the rubber rollers are arranged so that they are with rollers with solid surface interact. It is while trying one To seal such a chamber, a possible problem that a considerable Load on the roll structure may be required to seal maintain between the rollers. Accordingly, a more robust Frame required to limit the roll structure. It is at Attempting to seal such a chamber is another potential problem that any cuts in the rubber surface easily lead to it would make the entire roller unusable.

It has also been found that conventional wet-pressing processes thereby very inefficient are that only a small part of a roll circumference is used for processing the paper web. To this limitation some attempts have been made to overcome a firm, To adapt impermeable tape such that an extended gap formed for pressing the paper web and thus dewatered the paper web becomes. A problem with such an approach, however, is that the impermeable band, the flow of a drying fluid, such as air, prevented by the paper web.

Accordingly, there is a need for an improved fabric, which allows for improved drainage of a continuous web and effective sealing of a chamber at the nips provides.

The membrane according to the invention solution according to claim 1 brings a improved drainage of a continuous web, such as Paper, with itself and allows for effective sealing of a chamber at the nips in a pressing device.

Thus, the invention provides a uniform membrane according to for use in a pressing device. The pressing device comprises two in the longitudinal direction of the membrane extending edge portions and a semipermeable section with a variety of interconnected standing pores. The semipermeable section is between the arranged in the longitudinal direction of the membrane extending edge portions. The unitary membrane comprises a forming fabric and has a thickness less than about 2.54 mm (0.1 inch). The semipermeable section has a permeability of greater than zero and less than 0.025 m / s (five CFM per square foot) as determined by the TAPPI test procedure TIP 0404-20 measured (see claim 1).

In some of the particular specified in the dependent claims 2 to 9 Embodiments are the two extending in the longitudinal direction of the membrane Edge portions tapered such that a cross section of the uniform Membrane has a trapezoidal shape. Likewise, the two are in the longitudinal direction the membrane extending edge portions preferably impermeable.

The invention further provides a method for Producing the unitary membrane and comprises the steps specified in claim 10.

It is an advantage of the present invention when used in a pressing device is used with a pressurized chamber, the a plurality of rollers is formed so that they have a predetermined fluid flow through a continuous web, such as a paper web and a mechanical compressive force can cause this to to promote improved drainage of the continuous web.

It is a further advantage of the invention, when used in a pressing device is used, that the invention sealing a pressurized set chamber, which is formed of several rolls, two or supports more nips.

Advantageous embodiments of the invention Method are in the subclaims 11 to 18 specified.

Fig. 1

eine teilweise schematische Seitenansicht einer Ausführungsform der vorliegenden Erfindung,

Fig. 2

eine perspektivische Seitenansicht der Anordnung der Walzen der Ausführungsform von Fig. 1,

Fig. 3

eine Teilfrontansicht der Anordnung der Walzen der Ausführungsform von Fig. 1,

Fig. 4

eine schematische Darstellung einer Variante einer Endabdichtungsplatte der vorliegenden Erfindung,

Fig. 5

eine schematische Darstellung einer Variante einer weiteren Endabdichtungsplatte der vorliegenden Erfindung,

Fig. 6

eine in übertriebenem Maßstab dargestellte Seitenansicht einer Variante eines Hauptwalzenprofils der Erfindung,

Fig. 7

eine schematische Darstellung einer Variante der Ausführungsform mit einer einzigen Kammer von Fig. 1,

Fig. 8

eine schematische Darstellung einer Ausführungsform der Erfindung, die zwei Kammern umfaßt, und

Fig. 9

eine Explosionsteilschnittansicht, die Kammerabdichtungsaspekte der vorliegenden Erfindung veranschaulicht,

The invention is explained in more detail below with reference to embodiments with reference to the drawing; in this show:

Fig. 1

a partial schematic side view of an embodiment of the present invention,

Fig. 2

3 a perspective side view of the arrangement of the rollers of the embodiment of FIG. 1,

Fig. 3

a partial front view of the arrangement of the rollers of the embodiment of Fig. 1,

Fig. 4

a schematic representation of a variant of a Endabdichtungsplatte the present invention,

Fig. 5

a schematic representation of a variant of another end sealing plate of the present invention,

Fig. 6

an exaggerated scale side view of a variant of a main roll profile of the invention,

Fig. 7

1 is a schematic representation of a variant of the embodiment with a single chamber of FIG. 1, FIG.

Fig. 8

a schematic representation of an embodiment of the invention, which comprises two chambers, and

Fig. 9

FIG. 4 is an exploded fragmentary sectional view illustrating the chamber sealing aspects of the present invention; FIG.

Corresponding reference numerals indicate correspondingly throughout the views Parts on. The embodiments listed herein illustrate preferred embodiments of the invention.

Fig. 1 shows a pressing arrangement 10th shown, which is particularly useful in papermaking. The Press assembly 10 comprises a frame 12, a loading cylinder 14, a press roll assembly 16, a clamping structure 18, a membrane 20 and a control unit 21.

The frame 12 includes a main frame 22, an upper swing frame 24, a lower swing frame 26, an upper swing arm 28, a lower pivot arm 30 and a pair of side frames 32, 33. The Side frame 32 is shown with a broken-away part to an inner Part of the side frame 33 to expose. The pivot arms 24, 26 are, for example, by welding or screws, firmly on the Main frame 22 attached. The pivot arms 28, 30 are each about a plurality of pivot 34 in a conventional manner pivotally to the Swing frame 24, 26 mounted. Each pivot arm 28, 30 has a first End 36, 38, which is each designed such that it opposite Ends 40, 42 of the loading cylinder 14 via pins 44 receives. Each pivot arm 28, 30 has a second end 46, 48 which is formed, for example, by welding or screws, that it firmly holds the respective bearing housing 50, 52. The first and second side frames 32, 33 are on opposite sides of Main frame 22 mounted.

The press roll assembly 16 includes a plurality of rollers 60, 62, 64, 66 (four Rollers as shown) for cooperative rotation in the frame 12 are arranged. By cooperative rotation is meant that the rotational speed at the peripheral surface of each of the rollers 60, 62, 64, 66 together are substantially the same, wherein substantially no slip occurs between the roll surfaces. The expediency Sometimes, rollers 60, 62 are the main rollers and the rollers 64, 66 referred to as pressure rollers.

Referring to FIGS. 2 and 3 are generally all rollers 60, 62, 64, 66 closed Hollow cylinder each having a first circular end 68, 70, 72, 74, a second circular end 76, 78, 80, 82 and a cylindrical, middle peripheral surface 84, 86, 88, 90, and they are all each radially symmetrical about a rotation axis 92, 94, 96, 98. A set Gaskets 99 may be attached to the first circular ends 68, 70, 72, 74 and the second circular ends 76, 78, 80, 82. The Main rollers 60, 62 and pressure rollers 64, 66 are arranged axially parallel. The circumference of each pressure roller 64, 66 is smaller than the circumference of each Main roller 60, 62. According to FIG. 1, the rollers 60, 62, 64, 66 are arranged in such a way that that they have a corresponding number of nips 100, 102, 104, 106 define.

The pressure rollers 64, 66 are used to seal along the axial extent of the main rollers 60, 62 at the nips 100, 102, 104, 106. Each roller 60, 62, 64, 66 may be elastic Coating, such as rubber, comprise the seal to assist at the nips. The seal to the Nips 100, 102, 104, 106 requires a relatively uniform Pressure along all nips 100, 102, 104, 106. With the probable Bending of the main rollers 60, 62 due to the application of force to this through the pressure rollers 64, 66 is any mechanism necessary to create a uniform nip pressure on the Roll nips 100, 102, 104, 106 to assist. Accordingly For example, the pressure rollers 64, 66 may be hydraulic pressure and a series of pistons within the roll mantle of rolls 64, 66 to the roll shell of the rollers 64, 66 in the roll shell of the main rollers 60, 62 to apply a uniform pressure to the associated Provide columns. Alternatively, a crowned or a deflection compensating pressure roll could be used.

Referring to Fig. 3, the first and second side frames 32, 33 respectively a first and a second sealing plate 108, 110, to a Inside of these are mounted. The first and the second sealing plate 108, 110 are forced by the side frames 32, 33 to with a portion of the first circular ends 68, 70, 72, 74 or a part of the second circular ends 76, 78, 80, 82 of the rollers 60, 62, 64, 66 of the press roll assembly 16 to engage a Chamber 112 to define and thus a final seal of the chamber 112 effect. Optionally, at least one tie rod 113 is between a first sealing plate 108 and a second sealing plate 110 is connected in the chamber 112. In some embodiments the first and second sealing plates 108, 110 are flexible and so on constructed and formed so that they are each substantially to the Shape of the first circular ends 68, 70, 72, 74 and second circular Adjust ends 76, 78, 80, 82 of the rollers 60, 62, 64, 66. Around To further support the sealing of the chamber 112 are seals respectively between the first and second sealing plates 108, 110 and the first and second circular ends 68, 70, 72, 74 and 76, respectively, 78, 80, 82 arranged. Such seals can mechanical seals and fluid seals.

The main rollers 60, 62 are used on the side frames 32, 33 conventional bearing mounting structures, such as those, the rolling bearings or bushes, fixed rotatably mounted. In this context means fixed rotatably mounted, that the position of the axes 92, 94 of the rollers 60, 62 with respect to the main frame 22 and the side frames 32, 33 following the installation is not moved, but a rotation is allowed around the axes 92, 94 around.

Preferably, the main roll 60 extends over the membrane 20 in FIG Fluid communication with the chamber 112 is at least one void in Shape of a groove, a hole and a pore, in its central peripheral surface is formed to a pressure difference across the membrane 20th and any intermediate material, such as the continuous web 140, to relieve it. The main roll 62, which is not in fluid communication with the chamber 112 over the membrane 20, preferably comprises no such space in its central peripheral surface. each Roller may have an elastic coating, such as rubber over the entirety or part of its roll surface comprise the Seal the chamber 112 at the nips 100, 102, 104, 106 to support.

The pressure rollers 64, 66 are each rotatable on bearing housings 50, 52nd assembled. However, the axes of rotation 96, 98 of the rollers 64, 66 with respect to on the main frame 22 in each case via pivot arms 28, 30 movable to to cause a load of the press roll assembly 16. As the scope and the corresponding diameter of each pressure roller 64, 66 preferably smaller than the circumference and the corresponding diameter each Main roller 60, 62 are those generated on the pressure rollers 64, 66 Reduces forces, thereby reducing the forces within the smaller structures Chamber 112 can hold.

For example, the pressure rollers 64, 66, which are relatively smaller, require a lower actuation force than a relatively larger counterpressure roller would do. When the diameter of the pressure rollers 64, 66 a One third of the diameter of the main rollers 60, 62 can be on the pressure rollers 64, 66 forces applied in comparison with the forces on the main rollers 60, 62 are reduced by 40 percent.

The closer the distance between the main rollers 60 and 62, and ever greater the diameter difference between the main rollers 60, 62 and Pressure rollers 64, 66, the greater is generally the difference of Forces generated by the main rollers 60, 62 and the pressure rollers 64, 66 on the frame 12 is exercised. This arrangement allows the support structure, e.g. the frame 12, for the Preßwalzenaufbau 16 easier becomes. For example, because most of the force is due to the relatively larger Main rollers 60, 62 are applied, the main rollers 60, 62 on bearings mounted, which are fixedly attached to the side frames 32, 33, the in turn firmly attached to the main frame 22. By the Main rollers 60 and 62 structurally interconnected and their relative Positions are fixed, the main forces within the press assembly 10 within a relatively simple mechanical structure held.

In order to keep the membrane 20 under a suitable operating voltage, the clamping structure 18 is mounted on the main frame 22. The clamping structure 18 includes a clamping cylinder 114 and a tension roller 116. Die Tensioning roller 116 is rotatably coupled to the clamping cylinder 114, which is the Tension roller 116 in a direction transverse to the axis of rotation of the tension roller 116 moves.

As shown in Fig. 1 in relation to Fig. 2, the membrane moves 20 in the direction of arrow 118 and is over part of the peripheral surface 88 of the pressure roller 64, runs in an inlet nip 100th into, passes over part of the peripheral surface 84 of the main roll 60 within the chamber 112, runs out of the outlet nip 102nd out, passes over part of the peripheral surface 90 of the pressure roller 66th and runs around half of the peripheral surface of the tension roller 116 around. The membrane 20 is preferably a continuous one A band made of a semipermeable material that way is structured and designed to have a predetermined permeability which allows a predetermined fluid flow therethrough. Also preferably, the semi-permeable membrane 20 is up to one limited degrees both gas permeable and liquid permeable. In addition, the membrane 20 is structured and formed such that they seal the chamber 112 at the inlet gap 100 and at the outlet gap 102 supported. In the chamber 112, after this under pressure has been set, the combined effect of the inlet gap 100, the Membrane 20, which runs around the main roll 60 in the circumferential direction, and the outlet gap 102 to a single extended gap 115th for applying a mechanical compressive force in the direction of the main roll 60 and any intermediate material between the diaphragm 20 and the main roller 60 is arranged to form. Consequently is the membrane 20 with the pressurized chamber 112 and the main roller 60 in conjunction to simultaneously a predetermined Fluid flow through the intermediate material and through to cause a mechanical compressive force on this.

In preferred embodiments, the membrane 20 is approximately 2.54 mm (0.1 inch) or less thick and comprises a forming fabric, the Semipermeable is made by connecting several together standing pores 117 (shown by dots in Fig. 6) in the forming fabric are formed, which are a size, shape, frequency and / or pattern which is selected to provide the desired permeability becomes. The permeability is chosen to be greater than zero and less than about 0.025 m / s (five CFM per square foot) is as through TIPPI test method TIP 0404-20 is measured, and is particularly preferred chosen to be greater than zero and less than about 0.010 m / s (two CFM per square foot). Therefore, the semipermeable Membrane 20 to a limited extent both gas permeable and liquid permeable.

The membrane 20 is made semipermeable by a carrier fabric which is very permeable, and then several communicating pores 117 formed in the carrier web become. On the carrier fabric a padding is applied, the from a mixture of heat-fusible and not heat fusible fibers is made. The padding from the fiber mixture is sewn into the carrier fabric. On the sewn backing fabric Heat is applied to the heat-fusible fibers Melt, in turn, voids in the form of interconnected standing pores similar to those of a foam sponge, leave behind.

The membrane 20 preferably comprises two tapered, impermeable, longitudinally extending outer edges 20A, 20B adjacent to the semipermeable portion of the membrane 20 with each other in Compound pores 117 are formed. The outer edges 20A, 20B can be made impervious by heat fusible fibers at the outer edges of the membrane 20 in the absence melted by non-heat-fusible fibers.

The fiber mixture can be sewn into the carrier fabric to a Drag layer near the surface of the membrane 20, which will be located closest to the chamber 112.

Therefore, in operation, when exposed to chamber pressure, the pressure drop across the membrane 20 near the chamber side surface occur the membrane 20, thereby causing the membrane 20 entrains a minimal amount of chamber air. Because the membrane was entrained, pressurized fluid will release when released from the Chamber runs out, it is desirable, the entrained fluid volume so Small as possible to set up a waste of pressurized set chamber fluid to avoid. Therefore, it is preferable that the flow resistance layer close to the chamber side surface of the To put membrane, and it is preferable to keep the tissue as thin as possible, preferably less than 2.54 mm (0.1 inch). additionally it is preferred that the percentage of membrane void space be as low as possible, preferably less than 40 percent. The chamber side Surface is preferably also resistant to abrasion. The rest of the Tissue that does not comprise the fiber blend may act as a fluid distribution layer act, which receives a fluid flow from the resistive layer and the fluid flow over the underlying continuous Railway 140 distributed.

Alternatively, the communicating pores 117 of the Membrane 20 is formed by applying coating layers to the carrier fabric are applied until the desired permeability is reached. The Permeability is adjusted by changing any parameter of: the type of coating, the entrainment of air into the carrier, to form a foam, and adjusting the solids content of the Coating. The coating process is stopped when the desired Flow resistance level of the membrane 20 is reached.

The control unit 21 comprises a controller 120, a compressed air source 122, a fluid source 124, a differential pressure source 125, and a sensor assembly 126th

The controller 120 preferably includes a microprocessor and a Memory for storing and executing a control program, and comprises an I / O device for establishing the input / output communication and data transmission with external devices. Of the Controller 120 may be, for example, an industrial programmable Controller of a type that is well known in the art.

The compressed air source 122 comprises a plurality of individually controllable outputs. The Compressed air source 122 is connected to the loading cylinder 14 via a line 128 fluid coupled. The compressed air source 122 is also with the clamping cylinder 114 via line 130 fluid coupled. While the preferred working fluid, to operate the cylinders 14, 114 is compressed air, Professionals will find that the compressed air system is against another Fluid source could be exchanged, which is another gas or a used liquid working fluid.

The fluid source 124 is fluidly coupled to the chamber 112 via line 132. The type of fluid depends on the type of user Material that processes the pressing assembly 10, selectable. For example For some applications, compressed air may be desirable to use the chamber 112 to a predefined pressure to pressurize, in preferred embodiments of the invention is a pressure greater than 2,0684 Pa (30 psi) above the pressure of the differential pressure the differential pressure source 125 is. For other applications For example, it may be desirable to have a pressurized gas, such as a heated one Gas, or a liquid, such as water, or a liquid solution too use.

In the embodiment of FIG. 1, fluid flows into the chamber 112 the conduit 132 and flows out of the chamber 112 via the voids, For example, grooves, holes or pores in the middle peripheral surface 84 of the main roll 60 are formed out. The voids in the main roller 60 are connected to the differential pressure source 125 via a Line 133 in connection. The differential pressure source 125 may, for example a vacuum source, a pressure source operating at a pressure, which is lower than the pressure in the chamber 112, or simply one Vent to the atmosphere, which is via line 133 to the interior the roller 60 is coupled to effect evacuation of the voids.

Alternatively, venting via line 133 is not necessary if the Main roll 60 includes grooved spaces and the grooves with Atmospheric pressure. Similarly, a vent be removed via line 133, when the roll voids, such as blind holes, are big enough, and when they enter the gap at a pressure, which is lower than the chamber pressure. In this case, the Empty spaces act as a differential pressure source until the voids reach the Reach chamber pressure. The void size can be chosen such that the effectiveness of the dewatering process is controlled.

The pressurized chamber 112 has its own pressure relief, by causing excessive pressure build-up in the chamber 112 is that one or more rollers 60, 62, 64, 66 open to release the pressure instead of causing catastrophic failure.

The controller 120 is electrically connected to the compressed air source 122 via a Electric cable 134 connected to the fluid outlet of this selectively control and thus the operation of the load cylinder 14 independently to control and load on the Preßwalzenaufbau 16, and the Operation of the clamping cylinder 114 to control independently and thus a to provide predetermined voltage on the semipermeable membrane 20.

The controller 120 is electrically connected to the fluid source 124 via an electrical cable 136 connected. The controller 120 is also electrically connected to the Sensor assembly 126 connected via an electric cable 138. The sensor structure 126 includes one or more sensor mechanisms for electrical To provide feedback signals to the controller 120, one or the other Combination of a pressure, a temperature or a represent another environmental factor within the chamber 112. Of the Controller 120 processes the feedback signals to output signals to be supplied to the fluid source 124 to selectively the To control fluid output from this.

In operation, the controller 120 processes from the sensor assembly 126 received feedback signals to a pressure of the pressurized Chamber 112 preferably to control a pressure that is greater than 30 psi is above the pressure of the differential pressure source 125. The rollers 60, 62, 64, 66 are rotated with little or no slippage between them, and the membrane 20 is at the same speed as the Surface speed of the rollers 60, 62, 64, 66 driven. A continuous web or paper web 140 and a web support layer 142 are introduced into the intake nip 100 in the direction of the arrow 143 introduced and from the membrane 20 through the extended gap 115th passed through the outlet nip 102. The membrane 20 is inside the roller assembly 16 arranged so that they next to a first Page 144 of the continuous web 140 lies about their direct connection to effectively separate with the pressurized chamber 112. In other words, the fluid in the chamber 112 can not be on the continuous web 140 except through the membrane 20 through. The web support layer 142 is arranged so as to coincide with the cylindrical one Central surface 84 of the main roller 60 is in contact, and that with a second side 146 of the continuous web 140 is in contact.

The membrane 20 is structured and formed to have a permeability having a predetermined fluid flow therethrough through to the continuous web 140, and communicates with the pressurized chamber 112 and at least one void of the Main roll 60 in conjunction to a pressure difference across the membrane 20 and the continuous web 140 away. This pressure drop causes a mechanical compressive force on the continuous Web 140 is applied, which helps to solidify them. Therefore, it stands the membrane 20 with the pressurized chamber 112 and the Main roller 60 in combination at the same time a predetermined Fluid flow through the continuous web 140 and through to cause a mechanical compressive force on these and thus a to promote improved drainage of the continuous web 140.

The invention is particularly advantageous when the dry content of the continuous web 140 prior to dewatering is greater than about 6 percent and less than about 70 percent, and when the basis weight of the continuous web 140 is greater than about 25 g / m ² .

The web support layer 142 preferably has a thickness of approximately 2.54 mm (0.1 inch) or less and may be a felt or alternatively comprise a felt disposed adjacent to a hydrophobic layer, wherein the hydrophobic layer adjacent to the second side 146 of the continuous Path 140 is arranged. The web support layer 142 comprises preferably a felt layer 142A integral with a hydrophobic one Layer 142B is formed, wherein the hydrophobic layer 142B water transported away from the continuous web 140 by capillary action, so that it is picked up by the felt layer 142A (see Fig. 6). The hydrophobic layer 142B provides an effect of post-wetting protection ready, which prevents water from getting back into the continuous web 140 flows.

The relative sizes of the applied to the continuous web 140 mechanical pressure is caused by factors such as the chamber pressure in the chamber 112, the permeability of the semipermeable Membrane 20 and the permeability of the continuous web 140. The fluid flow, preferably air, through the continuous web 140 is influenced by factors such as the Chamber pressure in the chamber 112, the permeability of the semipermeable Membrane 20 and the size (e.g., length) of chamber 112. The dynamic Fluid pressure in the pressurized chamber 112 is at the Basis of the monitoring of the chamber pressure by the sensor structure 126 controlled. The sensor assembly 126 detects a pressure within the Chamber 112 and provides a pressure feedback signal to the controller 120. The controller 120 processes the pressure feedback signal to to generate a pressure output signal supplied to the fluid source 124 is to selectively control their fluid output and thus a pressure the pressurized chamber 112 at a predetermined pressure, preferably a pressure greater than 2.0684 Pa (30 psi) above the pressure of the differential pressure source 125 is to steer. When a temperature in relation to a pressure within the pressurized chamber 112 of FIG Is important, the sensor assembly 126 can be adapted so that a temperature within the chamber 112 detected and a temperature feedback signal supplies. The controller 120 processes the temperature feedback signal together with the pressure feedback signal, to generate output signals which are supplied to the fluid source 124, around the pressure and the temperature in the pressurized Chamber 112 to regulate.

The controller 120 also controls the loading of the main rollers 60, 62 by the pressure rollers 64, 66 by controlling a print size, the the loading cylinder 14 on the upper and lower pivot arms 28, 30 applies. The load size of the main rollers 60, 62 is preferably with a pressure in the pressurized chamber 112, monitored by a pressure sensor of the sensor assembly 126 becomes. The load can be a preload in addition to a load which is proportional to the pressure in the chamber 112.

Of course, variations are the embodiment described above possible. For example, and according to Fig. 4, to the end of the seal Chamber 112 to maintain and wear between the sealing plates 108, 110 and the rollers 60, 62, 64 and 66 to prevent a lubricating and sealing fluid, such as air or water, or any viscous fluid into a plurality of seal openings 148 via a conduit ring 150 are pressed with a fluid source 152 via a Line 153 is coupled. The pressurized fluid source 152 is electrically connected to the Controller 120 is coupled via an electrical cable 155 and is thereby controlled. The seal openings 148 in the seal plates 108, 110 are arranged so as to face the ends of the rollers 60, 62, 64, 66 are to pressurized lubricating and sealing fluid between the sealing plates 108, 110 and parts of the respective ones circular ends 68, 70, 72, 74 and 76, 78, 80, 82 forward. Due to the injection of the lubricating and sealing fluid, swim the sealing plates 108, 110 over the circular ends 68, 70, 72, 74 and 76, 78, 80, 82 in small controllable distances with little or without physical contact between the sealing plates 108, 110 and the circular ends 68, 70, 72, 74 and 76, 78, 80, 82 of the Rollers 60, 62, 64, 66. Although there is leakage around such a seal assembly is around, the size of the leakage is due to the careful Selection of distance tolerances and the lubricating and sealing fluid so controllable that she is small.

In addition, the main roll 62 is also intended to vent to a differential pressure source and that the continuous web 140 is guided together with the membrane 20 such that it passes through all four gaps through, such as in gap 106 in, from Gap 104 out into gap 100 and out of gap 102 to the To increase residence time over which the membrane 20 with the continuous Lane 140 interacts.

Fig. 5 shows another variant of the invention, in which the end seal the chamber 112 is improved by fluid openings 154 in sealing plates 108, 110 are arranged so that they are close to the Ends of the rollers 60, 62, 64, 66, however, arranged this not facing are. A conduit ring 156 is coupled to the openings 154 and is coupled to the fluid source 152 via line 158 to provide a lubricating and Sealing fluid, such as air or water, or any other viscous Fluid through the openings 154 into the chamber 112 inside supply. The fluid source 152 is electrically connected to the controller 120 coupled via electrical cable 155 and is thereby controlled. The pressure in the chamber 112, the added fluid presses between the circular ones Ends 68, 70, 72, 74 and 76, 78, 80, 82 of the rollers 60, 62, 64, 66th and the sealing plates 108, 110, thereby allowing the Seal plates 108, 110 float over the circular ends. In this embodiment, the leakage is controlled by the distance between the circular ends 68, 70, 72, 74 and 76, 78, 80, 82 of the rollers 60, 62, 64, 66 or sealing plates 108, 110 so controlled is that in any area an excessive leakage occurs, and that excessive wear between the sealing plates 108, 110th and rollers 60, 62, 64, 66 is prevented.

FIG. 6 shows another variant of the invention in which a main roll 160 having the profile shown would replace the main roll 60. The main roll 160 includes a first circular end 162, a second circular end 164, a first cylindrical end surface 166 and a second cylindrical end surface 168, a first inclined annular surface 170, a second inclined annular surface 172 and a cylindrical central surface 174. The first cylindrical end surface 166 is disposed adjacent to the first circular end 162, and the second cylindrical end surface 168 is disposed adjacent to the second circular end 164. The cylindrical center surface 174 has a circumference smaller than the circumference of the first and second cylindrical end surfaces 166, 168. The first inclined annular surface 170 provides a transition from the cylindrical central surface 174 to the first cylindrical end surface 166, and the second inclined annular surface 172 provides a transition from the cylindrical central surface 174 to the second cylindrical end surface 168.
The width of the central cylindrical surface 174 is selected to be approximately equal to the width of the diaphragm 20. The first and second inclined annular surfaces 170, 172 define a guide path for the membrane 20, the continuous web 140 and the web support layer 142. Each of the membrane 20 and the web support layer 142 preferably includes two tapered outer edges defining the first and second sloped annular surfaces 170, 172 touch. More preferably, the permeable membrane 20 includes two tapered, impermeable, longitudinally extending outer edges 20A, 20B formed adjacent a semipermeable portion 20C to enhance sealing along the inclined annular surfaces 170, 172. Also preferably, the web support layer 142 comprises a felt layer 142A and a hydrophobic layer 142B. Optionally, the web support layer 142 may include two impermeable, longitudinally extending outer edges contacting the first and second inclined annular surfaces 170, 172.

7 schematically illustrates a further variant of the invention, in which a pressing assembly 200 has a roller assembly 201 with a plurality Rollers 202, 204, 206, 208 which are in a quadrangular pattern for interacting rotation when processing a first continuous Web 209, such as a paper web, on a Web carrier layer 210 is taken, and a second continuous Web 212, such as a paper web, resting on a web support layer 214 is taken, is arranged. The web carrier layers 210, 214 may, for example, be felt layers.

Each of the plurality of rollers 202, 204, 206, 208 is of the above as main rollers 60, 62 and / or 160 and pressure rollers 64, 66 described Type and is therefore not described in detail again. It is also to understand that sealing plates of the same general type, as described above with respect to the sealing plates 108 and 110 were in the manner described above with reference to Figs. 4 and 5 would be used to define a chamber 216. The tax- and pressure source ports for the chamber 216 and associated ones Operation is as described above with respect to Figs. 1-4 which is therefore not repeated here.

For purposes of this discussion, rolls 202 and 204 will be main rolls and rollers 206, 208 are referred to as pressure rollers, Although in the present embodiment, the rollers 202, 204, 206, 208 are approximately the same size. The main rollers 202, 204 and the pressure rollers 206, 208 are arranged to have a plurality of Nips 220, 222, 224, 226 define, of which on the Based on the rotation of the main roller 202 in the arrow 230 the nips 220, 224 inlet nips of the Press assembly 200 form and the nips 222, 226 Auslaßwalzenspalten form.

The first continuous web 209 and the first web support layer 210 enter the inlet gap 220 and pass through the chamber 216 processed around the circumference of the main roll 202 around. The second continuous web 212 and second web support layer 214 enter the inlet gap 224 and are through the chamber 216 therethrough processed the peripheral surface of the main roller 204 around. The first web carrier layer 210, the continuous web 209, the continuous web 212 and the second web support layer 214 pass through the outlet gap 222 is processed to form a laminated web 228, the the continuous webs 209, 212 exists. During processing the second continuous web 212 remains due to the surface tension or due to the vent in the main roll 202 through holes, Grooves or pores in the cylindrical surface of the main roll 202 are formed in contact with the first continuous web 209. It is intended that the second continuous web 212 and the second web support layer 214 through one on the continuous web 209 applied coating layer could be replaced.

Fig. 8 is a schematic illustration of another embodiment of the invention, in which a pressing assembly 300 is a roller assembly 301 with a plurality of rollers 302, 304, 306, 308, 310 and 312, which belongs to interacting rotation when processing a continuous Web 314, such as a paper web are arranged. each Roller 302, 304 is of the type previously described as main roller 60 and / or 160 Kind and is with a differential pressure source in a way fluid coupled, which is described above. The rollers 306, 308, 310, 312 are of the above with respect to non-vented main and pressure rollers, such as the main roll 62 and the pressure roll 64, described Type and are therefore not described in detail again. Likewise is the sealing plate 316 of the same general type as above with respect to the sealing plates 108 and 110, and can be used in the manner described above with reference to FIGS. 4 and 5 become.

For purposes of this discussion, rolls 302 and 304 will be main rolls and rollers 306, 308, 310 and 312 are referred to as Pressure rollers referred to, due to their respective main function within a given chamber with respect to the continuous web 314. In the present embodiment, the rollers 302, 304, 306, 308, 310 and 312 are approximately the same size. The main rollers 302, 304 and pressure rollers 306, 308, 310, 312 are arranged so that they define multiple nips 320, 322, 324, 326, 328, 330, 332 whose basis is a rotation of the main roll 302 in the direction indicated by the arrow 334, the nips 320, 326, 330 are inlet nips of the press assembly 300, the nips 322, 328, 332 Outlet nips form and the nip 324 forms a chamber dividing nip is. The orientation and / or size of the rollers 302, 304, 306, 308, 310 and 312 may be modified such that the nips are arranged at the desired locations and the efficiency of Processing is optimized.

The sealing plates 316, together with the rollers 302, 304, 306, 308, 310 and 312 a first chamber 336 and a second Chamber 338, wherein each chamber has at least one inlet gap and at least an outlet gap is assigned.

A first pressure source 340 is connected to a chamber 336 via a conduit 342 fluid coupled, and a second pressure source 344 is with a chamber 338 via a line 346 fluid coupled. Lines 342 and 346 extend each of the sealing plate 316 in the chambers 336th or 338 into it to distribute a flow of fluid therein. The controller 120 is electrically coupled to the pressure source 340 via an electrical cable 348 and is electrically connected to the pressure source 344 via an electrical cable 350 coupled. A sensor assembly 352 is electrically connected to the controller 120 connected via an electric cable 354. The sensor assembly 352 is such configured to measure the pressure and temperature of each chamber 336, 338 monitored.

The pressing assembly 300 further includes a first semipermeable membrane 360 and a second semipermeable membrane 362. The membranes 360, 362 interact with the peripheral surfaces of the main rollers 302, 304, around a first extended gap 364 and a second to define extended gap 366. The extended gap 364 is located is in the first chamber 336, and the extended gap 366 is located in the second chamber 338.

The continuous web 314 includes a first side 370 and a second side Page 372. While in the chamber 336, a fluid is flowing through the continuous web 314 in a first direction from the first side 370 to the second side 372 at the extended one Gap 364. While in the chamber 338, a fluid is flowing through the continuous web 314 in a second direction opposite to the first direction, from the second side 372 to the first Page 370 at the extended gap 364. A first membrane 360 is with the first chamber 336 and the main roller 302 in conjunction to a mechanical pressing force on the continuous web 314 in the first Direction, i.e., from the first side 370 to the second side 372. A second diaphragm 362 communicates with the second chamber 338 and the main roller 304 in conjunction to a mechanical pressing force the continuous web 314 in the second direction, i.e., from the second Page 372 to the first page 370 apply. This is what the stand Diaphragms 360, 362 each with the respective pressurized Chambers 336, 338 and the respective main rollers 302, 304 in conjunction, in combination at the same time a predetermined fluid flow and a mechanical pressing force on the continuous web 314 in FIG to effect two directions and thus improved drainage the continuous web 314 to promote. In the present embodiment The main rollers 302, 304 each comprise at least one White space, such as a hole, a groove or a pore, to a pressure difference across the continuous web 314.

Preferably, each of the first semipermeable membrane is 360 and of the second semipermeable membrane 362 from a forming fabric approximately 2.54 mm (0.1 inch) or less thick and semi-permeable, by having a plurality of communicating pores 117 in the Form fabric formed with a size, shape, frequency and / or pattern which is selected to provide the desired permeability as described more fully above in connection with the membrane 20 is. The permeability of each of the first semipermeable Membrane 360 and the second semipermeable membrane 362 is chosen to be greater than zero and less than about 0.025 m / s (five CFM per square foot) is as by the TAPPI test procedure TIP 0404-20 measured, and in particular greater than zero and less than is about 0.01 m / s (two CFM per square foot).

In preferred embodiments, the pressing assembly 300 further comprises a first web support layer 361 and a second web support layer 363, each on opposite sides of the continuous web 314 are arranged. According to Fig. 8, the first web support layer 361 is between the diaphragm 362 and the rollers 302 and 312, and the second web support layer 363 is between the membrane 360 and the Rollers 306 and 304 are arranged. Alternatively, the first web support layer 361 be arranged so that they are between the continuous Web 314 and membrane 362, and the second web support layer 363 may be arranged to be between the continuous Lane 314 and the membrane 360 is located. Preferably, each of the Web support layers 361, 363 an integral fabric, the felt layer and a hydrophobic layer having a total thickness of approximately 2.54 mm (0.1 inch) or less, and is oriented such that the hydrophobic layer facing the continuous web 314.

Referring to Figure 8, the expanded gaps 364 and 366 are substantially the same length up. However, the gap lengths can be different which can be effected, for example, by main rollers chosen with different perimeters and / or by the perimeter size is changed by any one or more of the pressure rollers effectively the location of one or more nips 320, 324 and 328 to change.

The internal pressure of each of the first chamber 336 and the second Chamber 338 is individually controlled by controller 120 and can be pressurized to different pressures. The chamber 338 is preferably at a greater pressure than the pressure of the chamber 336 pressurized. In some cases it may also be desirable be to fill the chamber 336 with a first material and the Chamber 338 with a second material made from the first material different is to fill. Such materials can be dry air, Steam or gas, water or other fluid.

In addition to controlling the pressures in the chambers 336, it is in some If desired, the temperatures of the chambers 336, 338 on the to control the same or possibly different temperatures. Fig. 8 further shows a temperature control unit 374, which via lines 376, 378 is fluid coupled to respective chambers 336, 338, respectively the chambers 336, 338 a heating or cooling fluid, such as air, supply. The temperature control unit 374 is electrically connected to the controller 120 coupled via an electric cable 380. The controller 120 receives Temperature signals, which are the temperatures of the chambers 336, 338 from the sensor assembly 352. The controller 120 uses then these temperatures based on temperature output signals of predefined target temperatures, that of the temperature control unit 374 are supplied. The temperature control unit 374 then responds to the temperature output signals to the temperatures the chambers 336, 338 to regulate. The temperature of the chamber 338 is preferably controlled to be higher than the temperature of the Chamber 336 is.

Alternatively, the temperature control of the chambers 336, 338 causes in each case by the temperature of the first pressure source 340 and / or the second fluid source 344 to the respective chambers 336, 338 supplied fluids is regulated. In such a case, the temperature control unit 374 be eliminated.

FIG. 9 shows a part of the roller arrangement 400 which has a main roller 402 and a pressure roller 404 which, instead of those previously described Main rollers or pressure rollers can be used.

The main roll 402 has a general structure similar to that of FIG in Fig. 6 main roller 160 corresponds. While in Fig. 9 only one right end portion 406 of the main roll 402 is shown, the left end of the roller 402 is a mirror image of the right end 406 is and thus the same reference numerals that are used to to describe right end 406 for the left end of the main roll 402 will apply.

The main roll 402 includes a cylindrical central surface 408, left and right circular ends 410, left and right cylindrical end surfaces 412 and left and right inclined annular surfaces 414. The cylindrical End surfaces 412 are disposed adjacent to respective circular ends 410. The cylindrical central surface 408 has a circumference which is smaller is the circumference of the cylindrical end surfaces 412. The inclined ring surfaces 414 provide a transition from the cylindrical central area 408 ready for the cylindrical end surfaces 412. The cylindrical central area 408 includes at least one void, such as a groove, a hole or a Pore to a pressure difference across the membrane 20 and each intermediate Material across.

The distance between the inclined annular surfaces 414 of the main roll 402 is chosen such that it is approximately equal to the width of the semipermeable Membrane 20 is. The inclined annular surfaces 414 define a guide path for the semipermeable membrane 20 and the web support layer 142. Preferably, each of the semipermeable membranes 20 and 20 includes the web support layer 142 has two tapered outer edges, which are the inclined ones Touch ring surfaces 414. Particularly preferably, the semipermeable comprises Membrane 20 two tapered, impermeable, longitudinally extending outer edges 20A, 20B (see Fig. 6) to the seal along the inclined annular surfaces 414 to improve. The web carrier layer 142 comprises a felt layer 142A and a hydrophobic Layer 142B. The profiles of the semipermeable membrane 20 and the Web support layer 142 is preferably sized to fit into the web Roll profile of the main roll 402 between the inclined annular surfaces 414 fit so that the diaphragm 20 and the cylindrical end surfaces 412 in have substantially the same circumference height. In operation would be a continuous web, such as a paper web (not shown) between the semipermeable membrane 20 and the web support layer 142.

At the circular ends 410 are interchangeable end seals 416 attached, which include a plurality of fluid cavities 418. The attachment is caused by adhesive or fasteners. The interchangeable ones End seals 416 are preferably made of an elastic material, such as rubber, and can be a reinforcing fabric, like nylon or steel.

The pressure roller 404 comprises a generally cylindrical structure, the that corresponds to the pressure roller 64 shown in Figs. 1-3. While only a right end portion 420 of the pressure roller 404 is shown in FIG It will be understood that the left end of the pressure roller 404 is a mirror image the right end 420 is and thus the same reference numerals, which are used to describe the right end 420 for which left end of the pressure roller 404 will apply.

The pressure roller 404 includes a cylindrical central surface 422 and left and right circular ends 424. A sealing sleeve 426 having a Inner surface 428 and an outer surface 430 is above the cylindrical Central area 422 added and in a fixed relationship with the Pressure roller 404 held due to frictional forces acting between the cylindrical central surface 422 and the inner surface 428 of the sealing sleeve 426 act. Alternatively, the sealing sleeve 426 may be adhesive or by fasteners under the outer surface 430 of Sealing sleeve 426 disposed and in the cylindrical central surface 422 are held in their place. Preferably however, each sealing sleeve 426 is replaceable such that when the Sealing sleeve 426 shows an unacceptable level of wear, the sealing sleeve 426 without the need, the pressure roller 404th be discarded, can be exchanged. The sealing sleeve 426 comprises a stress layer 432 and a plurality of fluid cavities 434.

At the circular ends 424 are interchangeable end seals 436 attached, which include a plurality of fluid cavities 438. The attachment is effected by means of adhesive or fasteners. The interchangeable ones End seals 436 are preferably made of an elastic Material, such as rubber, and may be a reinforcing fabric, like nylon or steel.

The sealing sleeve 426 is preferably made of an elastic material, such as rubber. The stress layer 432 of the sealing sleeve 426 is used to apply the hoop or strapping stresses and / or stresses of the sealing sleeve 426 over the machine, and includes a reinforcing fabric, such as nylon or steel. The size, shape and geometry the fluid cavities 434 are chosen such that they in particular in the vicinity of the longitudinally extending edges 20A, 20B of FIG semipermeable membrane 20 are elastically deformable. Likewise preferred The fluid cavities 434 either extend in the circumferential direction the sealing sleeve 426 in a repeated pattern over the Width of the pressure roller 404 across, or across the width of the pressure roller 404 in a repeated pattern around the circumference of the sealing sleeve 426 around. Alternatively, the cavities 434 may become diagonal extend around the sealing sleeve 426 around.

The fluid cavities 434 are filled with a fluid, such as air, Water or gel, pressurized to a yielding, but firm Seal with the semipermeable membrane 20 around the cylindrical Maintain end surfaces 412 of the main roll 402. In a mold The invention relates to fluid cavities 434 at the time of manufacture the sealing sleeve 426 pressurized. Alternatively the compressed air cavities 434 at the time of manufacture of the sealing sleeve 426 not pressurized, but rather the sealing sleeve 426 include one or more valve ports 440, such as For example, the type that is commonly used to air in one To introduce pneumatic tire to absorb fluid and thus the cavities 434 under pressure. Alternatively, the valve opening (s) 440 open ports communicating with a fluid source via a fluid conduit and a rotatable fluid coupling are connected. In some applications For example, it may be desirable to communicate the fluid cavities 434 with each other connect to distribute any externally applied forces and effectively form a single cavity.

The fluid cavities 418, 438 of the interchangeable end seals 416, 436 are pressurized with a fluid such as air, water or gel. The size, shape and geometry of the cavities 418, 438 are chosen such that that they are elastically deformable to a yielding but firm Seal between the replaceable end seals 416, 436 and with the associated sealing plates, such as the sealing plates 108, 110 of FIG. 3. In one form of the invention the fluid cavities 418, 438 at the time of manufacture of the end seals 416, 436 pressurized. Alternatively, the fluid cavities become 418, 438 at the time of manufacture of the end seals 416, 436 not pressurized. Rather, the interchangeable ones End seals 416, 436 each one or more valve opening (s) 442, 444, such as the type that is commonly used is to introduce air into a pneumatic tire to absorb fluid and thus pressurizing the cavities 418, 438. In some applications it may be desirable to fluid cavities 418 together or to connect the fluid cavities 438 together. The Connecting the cavities effectively forms a single cavity to any externally applied forces within the formed single Distribute the cavity.

Claims (18)

1. A uniform membrane (20, 360 362) for use in a pressing apparatus having two edge sections (20A, 20B) extending in the longitudinal direction of the membrane (20, 360, 362) and a semi-permeable section (20C) having a plurality of pores (117) communicating with one another, wherein the semi-permeable section (20C) is arranged between the two edge sections (20A, 20B) extending in the longitudinal direction of the membrane (20, 360, 362); and
   wherein the uniform membrane (20, 360, 362) includes a forming fabric, the uniform membrane (20, 360, 362) has a thickness of less than 2.54 mm (0.1 inches) and the semi-permeable section (20C) has a permeability which is larger than zero and smaller than 0.025 m/ s (five CFM per square foot) as measured using the TAPPI test method TIP 0404-20.
2. A uniform membrane in accordance with claim 1, characterized in that the semi-permeable section (20C) has a permeability which is larger than zero and smaller than approximately 0.01 m/s (two CFM per square foot), as measured using the TAPPI test method TIP 0404-20.
3. A uniform membrane in accordance with claim 1, characterized in that the permeability is determined by at least one factor of the factors size, shape, frequency and pattern of a plurality of pores in the semi-permeable section (20C).
4. A uniform membrane in accordance with claim 1, characterized in that the two edge sections (20A, 20B) extending in the longitudinal direction of the membrane (20, 360, 362) are tapered such that the cross-section of the uniform membrane (20, 360, 362) is trapezoidal.
5. A uniform membrane in accordance with claim 1, characterized in that the two edge sections (20A, 20B) extending in the longitudinal direction of the membrane (20, 360, 362) are impermeable.
6. A uniform membrane in accordance with claim 1, characterized in that the forming fabric forms a flow resistance layer in the proximity of a surface of the uniform membrane (20, 360, 362).
7. A uniform membrane in accordance with claim 6, characterized in that the uniform membrane (20, 360, 362) includes a fluid distribution layer in addition to the flow resistance layer.
8. A uniform membrane in accordance with claim 1, characterized in that it includes a wear-resistant surface.
9. A uniform membrane in accordance with claim 1, characterized in that the semi-permeable section (20C) has an empty space percentage of less than 40 percent.
10. A method of manufacturing a uniform membrane (20, 360, 362) for use in a pressing apparatus comprising the steps:

    a forming fabric is provided which is permeable; and

    a plurality of pores (117) communicating with one another are formed in the forming fabric,

    characterized in that
    fibers meltable by heat and fibers not meltable by heat are mixed for the formation of a semi-permeable section (20C) having the pores (117) communicating with one another;
    in that the fiber mix is sewn into the forming fabric; and
    in that heat is applied to melt the fibers meltable by heat which leave empty spaces in the form of pores (117) communicating one another; and
    in that two edge sections (20A, 20B) extending in the longitudinal direction of the membrane (20, 360, 362) are formed between which the semi-permeable section (20C) is arranged,
    wherein the uniform membrane (20, 360, 362) has a thickness of less than 2.54 mm (0.1 inches) and the semi-permeable section (20C) has a permeability which is larger than zero and smaller than 0.025 m/ s (five CFM per square foot) as measured using the TAPPI test method TIP 0404-20.
11. A method in accordance with claim 10, characterized in that the sewing step comprises the step that the fiber mixture is applied inside the forming fabric in the proximity of its surface to form a flow resistance layer in the proximity of the surface of the uniform membrane (20, 360, 362).
12. A method in accordance with claim 11, characterized in that it comprises the step of defining a flow distribution layer in the uniform membrane (20, 360, 362) which distributes the fluid flow absorbed by the resistance layer.
13. A method in accordance with claim 10, characterized in that two impermeable edge sections (20A, 20B) extending in the longitudinal direction of the membrane (20, 360, 362) are formed.
14. A method in accordance with claim 10, characterized in that the formation step comprises the steps that
    a resistance layer is formed; and
    a fluid distribution layer is formed.
15. A method in accordance with claim 10, characterized in that the formation step comprises the step that a coating is successively applied to the forming fabric until the desired permeability has been achieved.
16. A method in accordance with claim 15, characterized in that it comprises the step that the type of coating is modified to adjust the permeability.
17. A method in accordance with claim 15, characterized in that it comprises the step that air is entrained in the coating to adjust the permeability.
18. A method in accordance with claim 15, characterized in that it comprises the step that the solid content of the coating is modified to adjust the permeability.

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