FI119632B - Method and apparatus in a paper web reel - Google Patents

Description

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The invention relates to a method according to the preamble of claim 1 in a paper web reel.

The invention also relates to a device according to the preamble of claim 7 in a paper web reel.

EP 0369977 discloses a method and apparatus in a paper web reel, wherein the roll is formed around a reel axis and / or on support rolls or support belts, and which method and device uses a reel web? which forms a scrolling nip with the roll. The deflection of the cylindrical shell rotating about the center roll of the roller cylinder is controlled by a loading device, for example a hydraulic device, and by means of the deflection, the linear pressure distribution of the roller nip is controlled, e.g.

Figure 4 shows an embodiment in which the axis and sheath of the winding cylinder; The space between the two is sealed into two parts. A pressurized medium which is adjustable in pressure is introduced into a part space facing the forming web roll 20. The pressure medium adjusts the line pressure of the winding nip so that a steady line load is achieved at various stages of the winding.

EP 0912435 discloses a method and a reel for continuously rolling a web 25 of material. The reel comprises a movable reel cylinder for forming a reel nipple, wherein in the disclosed method the line load of the reel nip is controlled by a movable reel cylinder. In the arrangement disclosed in the reference, the winding cylinder moves horizontally or at an angle. For example, a deflection compensated reeling cylinder is used as the reeling cylinder.

DE-A-4418549 discloses a bombable roll which preferably forms a nip with another roll. The roll comprises a shaft having at its ends shaft pins through which the roll is rotatably mounted on the bearing brackets. The roll ends have end portions supported by shaft pins, on which the roll casing is supported by supports 5. The coolable sheath of the roll consists of two cylindrical sleeves supported by stairs between the end portions of the roll and the end portions.

The roll shell thus rotates with the shaft. There is a space between the inner cylinder sleeve of the jacket and the shaft which can be supplied with a medium for cooling the jacket of the roll or for bombarding the jacket. The pressure of the medium in said space can be adjusted by adjusting the volume of the space through a plurality of threaded pins extending from the end portions into the space. Turning the pins so that they lean deeper into the space will reduce the volume of the space, thereby increasing the pressure of the medium in the space and vice versa. The radial thickness of the inner cylinder sleeve of the jacket may vary in the axial direction of the roll, e.g., such that the inner cylinder sleeve 15 is thicker at the ends of the roll and thinner at the center of the roll. Such a variable shell thickness profile can influence the shape of the shell bombardment. An example of an embodiment is disclosed in which a roll forms a nip with another roll and to this nip is fed a molten plastic from which a plastic film is calendered. λ 20 In prior art applications, the use of a deflection compensated roller roller as a roller roller cylinder has been aimed at providing a uniform / desired nip force profile with the miller and eliminating the problems caused by an eccentric nip load. In addition, attempts have been made to solve the problems of the paper profile in the transverse direction and the problems of air forming with the paper web. The above-described technology; however, solutions known from the prior art have not been able to completely eliminate the winding problems described above. In addition, as is known in the art, problems with the nip force may occur with the nip force, for example due to changes in the friction of the conductors, which cannot be detected, for example, in pressure measurements of hydraulic cylinders or force sensors.

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Also known in the art are rollers which have been bombarded on the outer surface of the mating cylinder shell. The problem with these applications, however, is that the bombardment will function as desired only at a certain roll diameter and nip load level. Generally, prior art bombee-5 blades achieve the ideal bottom of a forming roll, but larger roll diameters do not provide prior art bombardment.

As the diameter of the forming roll increases, the bombardment must be such that air entrained in the paper web is not conducted inside the forming roll, and at the same time, the venting inside the roll must be functional. Bombing in known solutions of the prior art allows compensation of a nip deflection with a certain constant nip load. Attempts have been made to determine the correct value of the bombardment by calculating using many different types of parameters, but sufficiently good nip shape, e.g., straightness is very difficult to achieve over the entire required line loading range as the roll diameter changes.

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It is an object of the present invention to provide a winding cylinder so that the disadvantages and problems of the prior art solutions described above are eliminated or at least minimized.

It is a further object of the invention to provide a winding cylinder such that its applications are more versatile and reliable than prior art solutions.

It is also an object of the invention to provide a deflection adjustable winding cylinder which eliminates or at least minimizes the problems of prior art solutions associated with bombardment of a milling cylinder.

In order to achieve the above stated objectives, the method of the invention is essentially characterized by what is set forth in the characterizing part of claim 1.

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The device according to the invention, in turn, is essentially characterized by what is stated in the characterizing part of claim 7.

Preferably, the casing of the winding roller 5 used in connection with the method and apparatus of the invention is a composite material, for example glass fiber or carbon fiber, which provides an advantage in manufacturing costs because the manufacturing process is simple and fast and raw materials are inexpensive. In addition, the roller is more sensitive to operation than prior art rollers because the composite-curved deflection-adjustable roller is lighter, less frictional and particularly sensitive to low forces, e.g., less than 1 kN / m. When the composite material is used as the sheath material for the deflection adjustable roll, low shear pressures provide sufficient sheath movement to provide the necessary nip force to the winding nip.

According to the invention, the deflection-adjustable winding cylinder is implemented such that the winding cylinder has a single zone over the entire shell area. In this way, the adjustability of the bulge (bombardment) can be achieved by making, e.g., turning the inside of the jacket in the cross-machine direction during manufacture to the desired thickness profile. In this case, a thinner-than-usual sheath or a composite sheath may be used, whereby a bulging of the sheath may be effected at low pressure. Such a roller is well suited for use in roller reeling roller applications as nip rolls for paper and coating machines, such as press, calender, coating stations, etc.

pro-profile as a function of pressure. The amount of pressure I adjusts the bulging of the jacket

adjusting so that the transverse profile is created by the properties of the sheath, i.e., by the sheath thickness profiles determined at the time of manufacture; most preferably, a thin or composite jacket is used which provides sufficient bulge (bombardment) at low pressure, for example below 10 bar. This provides a simple adjustable roller construction! .¾ ji 5 · 'ϋ * bulk cylinder / nip roll for deflection and nip straightness control. Such; the reeling cylinder can be particularly well used in rebuilding, whereby the normal deflection-adjustable cylinder in the object to be modernized is replaced by a cylinder according to the invention, whereby the inner shell is bombarded, e.g.

The invention adjusts the nip force profile of the reel winding cylinder at each stage of operation of the reel, for example, by employing a direct nip force profile during tapping and a direct or medium-weight nip force profile during winding.

In the following, the invention will be described in more detail with reference to the figures in the accompanying drawings, the details of which, however, are not intended to be limited in any way.

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Figure 1 schematically shows a bombardment of a winding cylinder.

Figure 2 schematically shows the deformation of the sheath in the longitudinal direction of the sheath, depending on the thickness of the sheath, at some starting values.

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Referring to Figure 1, the winding cylinder 10 is formed into a single zone so that its interior space 13 is pressurized as indicated by arrow P. In order to obtain the desired bombardment B, the roll shell 12 of the winding cylinder 10 is fabricated from its thickness profile to The thickness of the wall of the sheath 12 may vary, for example, such that the sheath 12 is thicker at the periphery and narrower at the center, resulting in bulge B outward,; in the middle region as shown in the figure. The shape of the bulge is determined by the shape made in the diaper 12 at the manufacturing stage and by the pressure level of the interior space 30 13.

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2, the shell 12 is deformed with the thickness of the shell 12 shaped as shown in FIG. 2A in accordance with curve 21. By way of comparison, the curve also shows the situation with a flat jacket, denoted by curve 22. In the example, the X-axis has a length-5 direction of the diaper from the edge of the diaper to the center of the diaper and a Y axis. The exemplary curves 21, 22 of the figure are illustrated in a situation where an internal pressure of 10 bar is used.

According to a preferred embodiment of the invention, the roll shell 12 is a composite material 10, e.g. 20 to 50 mm thick, whereby the weight of the roll shell is light because the density of the composite materials (e.g. carbon fiber approx. 1550 kg / m2, glass fiber 2000 kg / m2) density (about 7800 kg / m3).

The invention has been described above with reference only to some preferred embodiments thereof, the details of which, however, are not to be construed in any way as being narrowly limited.

Claims (9)

A method in a paper web reel, comprising forming a web reel (11) around a reel axis and / or a carrier on rolls or straps, using a reeling cylinder (10) which forms a reel nip (N) with a reel (11) ), a pressure medium (P) is applied to the space between the central axis and the roller sheath (12) rotating about the central axis to form an adjustable load on the nip force and / or nip force profile in the winding nip (N). 10) in the axial direction, whereby a bombardment (B) is formed on the roll shell (12), the shape of which depends on said thickness profile and the pressure of the pressure medium in question. Method according to Claim 1, characterized in that ral-15 cylindrical cylinders (10) are used, the deformation of the roll mantle (12) in the axial direction of the roll mantle (12) being in the radial direction of 0.006-0.010 mm when using an internal pressure of 10 bar. pressure. Method according to claim 1 or 2, characterized in that 20 winding cylinders (10) are used, the roll shell (12) of which is made of a composite material. Method according to one of Claims 1 to 3, characterized in that the winding cylinder (10) is adjusted to an optimum nip force profile according to the operation of the winder 25. Method according to Claim 4, characterized in that the nip force profile is adjusted straight during the winding of the web at the beginning of the winding. 30 4 '. '* 8 I- · i Method according to Claim 4, characterized in that during the winding the nip profile is adjusted straight and / or centered. A device in a paper web reel, in which the web reel (11) is formed * 5 around a winding axis and / or on support rolls or carrier belts, comprising a winding cylinder (10) forming a winding nip (N) with a roll (11) (10) comprises a rotatable roller sheath (12) disposed about the central axis, wherein a pressure medium (P) is introduced into the space between the central shaft and the roller sheath (12) to adjust the nip-10 force and / or nip force profile wherein the radial thickness profile of the roll shell (12) varies in the axial direction of the winding cylinder (10), whereby the roll shell (12) is bombarded (B), the shape of which depends on said thickness profile and current pressure medium pressure. Device according to claim 7, characterized in that the deformation of the roller cylinder (10) ·: in the axial direction of the roller shell (12) in the radial direction of the roller shell (12) is 0.006-0.010 mm when used inside the shell. pressure of 10 bar. '>' Ji Device according to Claim 7 or 8, characterized in that the roll shell (12) of the winding cylinder (10) is made of a composite material. 9