FI123535B - Fastening roller and method for winding a fibrous web - Google Patents

Description

Fastening roller and method for winding up a fibrous web - Upprullningsan-ordning och förfarande för att roll upp en fiberbana

The invention relates to a reel for continuously wounding a fibrous web around a reel roll to a machine reel comprising a reeling cylinder for forming an en-5 reel nip with a reel reel and a secondary nip roll for forming a reel nip with a reel reel.

The invention also relates to a method for continuously wounding a fibrous web around a reel roll into a machine reel, the method comprising forming a primary nip with a reeling machine reel and a secondary nip with a secondary nip 10 to form a secondary nip with a reeling machine reel.

A roller winder is a device that winds material produced as a continuous fibrous web into a roll of a machine. In a fiber web production process, rewinding is generally the first sub-process in which continuous production is interrupted sequentially. The machine reel is formed around a reel core 15 serving as a reel core, i.e. one fiber web on the reel has a beginning and an end. A constant trend in the industry is the steady increase in the size of machine rolls, which causes a constant need for further development of the reels. However, since it is a dynamic environment and the fibrous web is a rollable material susceptible to various faults, the role of the reel roller in maintaining the efficiency of the paper or board machine is very significant. One of the reasons for the steady growth of machine rolls of 20 sizes is the desire to have fewer disruptive or distracting beginnings and endings for efficiency in fiber web production.

Controlling the runnability and winding of lightweight fibrous webs by the coil winder co is particularly challenging, since lightweight fibrous web types are generally weaker than heavy fiber webs of tensile or tear strength and thus susceptible to damage, g. , until the end of the fibrous web can be retracted

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through the production machine and rewinding to start a new reel reel. When replacing the machine roll £, the fibrous web is intentionally cut and the fibrous web coming from the production machine is guided to roll around the new reel roll. For light fiber types, this is in a sense a simple operation because the fiber web is easily broken o. On the other hand, the fibrous web may not break in the desired manner, in which case the fibrous web will be broken, but will not roll in the desired manner around the new reel reel. In some cases, the bottom of the machine reel forms a multiple folded pile at the base of the fibrous web 2 which "" appears "through a plurality of reeled layers, causing a possible winding failure.

As fiber web production rates increase, denser as well as smoother types of fiber webs, such as heavily calendered or coated paper and board grades, have caused ai-5 to increase the use of a soft-surface winding roller because the soft surface can reduce air consumption. In the immediate vicinity of the fibrous web, air passes at the same speed as the fibrous web. This air entrained with the fibrous web is commonly referred to as boundary layer air. In practice, high-speed non-woven web winding is a two-component, 10-reel winding with both a fibrous web and an air film running on both sides of the fibrous web.

While the lightweight and potentially tear-resistant fibrous web described above is still poorly air permeable and smooth, the winding of the fibrous web is a particularly challenging task. Known winding parameters must be selected very accurately according to the driving situation, and must be repeatable once and again with very high accuracy. The weighting of the winding parameters may be different from that of a conventional "easy" winding fiber web.

It is an object of the invention to provide a roller coil which is particularly well suited for smooth and air-permeable, possibly low-tensile fiber types. One particular object is to provide a reel which is suitable for continuous operation as the first reel of a fiber web line, whereby, for example, the coating and / or calendering of the fiber web is performed as an on-line process. It is also an object of one embodiment of the invention to provide a reel with particular attention to serviceability with respect to the requirements of the first 25 reel of the fiber web, with the aim of making all critical components of the reel as easy and fast as possible. endeavor to minimize. Compared to the off-line reel, the on-line reel se- curity time is more critical because there is no production during the on-line reel downtime. The off-line reel, in turn, can later "shut down" stock production, where serviceability is not as critical.

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O) In the description of the present invention, the following designations are used for ease of explanation: the machine direction (MD) is called the x-direction, the cross direction (CD) is called the y-direction 35, and the elevation is called the z-direction. . The upstream direction of the fibrous web is referred to as the upstream direction and the upstream direction of the fibrous web is referred to as the downstream direction. The reel core is referred to herein as the reel spool, but it could equally be called the reel axis.

The rewinder roller according to the invention is characterized in that the winding cylinder 5 is hard surface and vented and the secondary nip roll is soft, whereby a surface drawing difference can be formed between the primary nip and the secondary nip so that the radial deflection

The method according to the invention is characterized in that a hard surface and a veneer rolled cylinder provides a primary stretch and a primary compression on the fibrous web and a soft surface secondary nip roll provides a secondary stretch and secondary extrusion radial depression with corresponding line load.

This provides an object-oriented adhesive reel and a method for retracting a fibrous web which is particularly well suited to thin, slippery, and low air permeable fibrous webs. By means of the invention, the fibrous web can be gradually tensioned on a fibrous web roll in such a way that the boundary layer air is optimally removed between the fibrous web layers and at the same time the fibrous web is stretched by tension roller and secondary nip rollers. For slippery fibrous web types, removal of said boundary layer air is particularly important because the boundary layer air acts as a lubricant between the fiber web layers. This feature is particularly emphasized in low air permeable fiber webs.

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The invention will now be described in more detail with reference to the accompanying drawings, in which: FIGS.

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Figure 1 shows an example of a winder,

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Figure 2 shows another example of a reel winder,

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Fig. 3 shows an example of venting of the winding cylinder, and Fig. 4 schematically shows the factors affecting the tension of the machine roll as a function of the diameter of the machine roll.

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Fig. 1 shows an example of a winder 1 applying the invention for continuously winding a nonwoven web around a reel roll 5 into a machine roll 6 comprising a winding cylinder 10 to form a primary nip NP with a winding machine 6 and a secondary nip 10 is hard surface and vented 11, secondary nip roll 18 is soft surface 181, whereby a surface tension difference can be formed between primary nip NP and secondary nip NS such that radial deflection of secondary nip roll 18 to machine roll is less than the radial deflection of the winding cylinder. In Fig. 11 the torque Te of the winding cylinder 10, the torque Tr of the center drive and the torque Ts of the secondary nip roll 18 are shown in their direction of rotation, but as will be explained later, each torque may also be applied in its opposite direction, i.e. rotation. The tension Tw of the fibrous web before the winding cylinder is practically achieved by the speed difference between the winding cylinder and the preceding rolling roll.

Correspondingly, the method of continuously winding the fibrous web W around a reel roll 5 into a machine roll 6 can be applied to the reel of Fig. 1, wherein the reel 1 and the vented winding cylinder 10 provides a primary stretch and a primary compression of the fibrous web and a soft surface 181 secondary nip roll 18 provides a secondary elongation and secondary compression, whereby a surface tension difference between the primary deflection co with corresponding line load. Line load, as used herein, refers to the computational property of the nip load, considering only the width of the nip in the y-g direction and the applied force, but excluding other factors such as nip length in the direction of the web (x) and the like.

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30 ta. The line load unit is typically used in kN / m.

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In one embodiment of the invention, there is a connection between the primary nip NP and the secondary nip NS

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The distance g is greater than 60 degrees, preferably greater than 90 degrees, based on the center angle of the machine roll. This distance has an effect on the stretch length of the fibrous web 00 after the primary nip NP and before the secondary nip NS makes its own portion of the tightness of the machine roll to be formed.

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Fig. 2 shows another example of a reel applicator applying the invention in which the position of the primary nip NP and secondary nip NS differs slightly from that of Fig. 1. Otherwise, the features of the retractors 1 of Fig. 1 and 2 are the same.

Fig. 3 shows a veneer 11 of the winding cylinder 10 according to one embodiment. The vent 11 of the winding cylinder 10 comprises a circumferential groove having a single groove width 111 of about 2 ± 1 mm, a groove depth 112 of about 4 ± 2 mm and about 10 ± 5 mm. The venting may be the same across the entire width of the winding cylinder or the width of the fibrous web W, or the venting 10 may vary for some or some of the above parameters, for example from the centerline CL towards the edge of the fibrous web. Suction channels 114 may also be provided in connection with the venturi to provide a vacuum or overpressure effect. The venturi may also be arranged in a spiral shape such that in the axial direction the groove extends, for example, from the center towards the edges. The venturi may also be formed in multiple heads, whereby the coil described above is formed by a plurality of parallel grooves, such as seven grooves. This creates an elevation of the vent that is seven times the slot.

According to a further embodiment, the surface of the winding cylinder 10 may also be coated with a carbide or similar coating with a coarser coating relative to the surface of the fibrous web, thereby improving the frictional properties between the winding cylinder and the fibrous web. One commonly available technique for providing such a hard and high friction coating on the surface of the winding cylinder 10 is thermal spraying. The hard surface winding cylinder may also mean in this context, for example, a surface of a winding cylinder having a hardness of 105 to 90 ShA, preferably 103 to 98 ShA.

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o ™ According to a further preferred embodiment, the retractor comprises means for oscillating the machine roll 6 with a variation in the y-direction of the fiber web W on the machine roll 6. Thin, slippery and low air permeable fibrous webs are characterized by relatively small moisture, thickness, filler or the like, across the fibrous web

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in the g direction, i.e. the y direction, easily causes a big difference in scrollability. In this case, circumferential ridges may form inside the machine roll, which may suddenly slip relative to one another and cause damage to the fibrous web. Therefore, it is advisable to roll up such profile defective fiber webs by oscillating.

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Figures 1 and 2 show a secondary nip roll 18 which has a soft surface. In this art, the roll can be said to have a soft surface with a hardness of 60 to 120 P&J, more preferably 85 to 105 P&J. With the hardness of the secondary nip roll within the above range, it is possible to achieve a situation in which the radial deflection of the secondary nip 5 on the machine roll is less than the radial deflection of the winding cylinder with the corresponding line load. It should also be noted that the thickness of the soft coating 181 and the ratio of the diameters of the winding cylinder 10 and the secondary nip roll 18 have an effect on the indentation. With very thin coating thicknesses, such roller coating indentation does not occur, but the deposition occurs solely on the machine roll side. Therefore, it is recommended that the soft coating 181 of the secondary nip roll be selected to have a thickness greater than or equal to 15 mm, however, taking greater account of the characteristics and other conditions of the fiber web being produced. Correspondingly, the diameter ratio of the winding cylinder 10 and the secondary nip roll 18 is preferably less than 2: 1. It is also to be noted that, according to the preferred embodiment 15, the secondary nip roll 18 is full width, which means that the effective width of the secondary nip roll is the width of the entire fibrous web on the machine roll including any oscillation offsets.

Figure 4 shows schematically the factors affecting machine roll tension H as a function of machine roll diameter D. According to a preferred embodiment 20 of the present invention, the winding parameters are selected such that the ratio of the primary nip to the secondary nip to produce the winding force is varied for each type of fiber web. The more sensitive the fiber web is to produce, the more precise and finer this adjustment must be. The machine roll has a minimum tension Hmin below which tension inside the machine roll causes harmful skidding.

According to the invention, the primary nip is used to remove most of the boundary layer air passing through the fibrous web 5. The small nip load in the primary nip NP has the advantage of producing a WOT c / j with a hard reeling cylinder and the torque of the machine roll center drive Tr. The fiber web layers must be able to slide in the nip relative to one another in order to

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^ fiber web stretching and roller tension increase occur. Then the primary nip nip | 30 loads are relatively smaller than the secondary nip load, so that the fiber web layers at the primary nip can slip over each other

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§ for providing a machine roll at least to the outermost fiber web layer. Thus, the primary nip NP acts primarily as a vent nipple, but nevertheless, the torque Te of the winding cylinder and the primary nip produces more than 50% of the tension of the machine roll. As a result of this division, it is advantageous for the center roll drive torque Te and the secondary nipple to form nearly 50% of the machine roll tension.

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The weighting is thus slightly primary nip-weighted, but still close to 50:50.

According to a further embodiment of the method, the circumferential force reduced by the torque Ts of the secondary nip roll on the surface of the machine roll is greater than the circumferential force reduced by the torque Te of the winding cylinder on the surface of the machine roll. The circumferential force caused by the torque is practically calculated by dividing the roll torque by the radius of the roll and similarly, by dividing the center drive torque Tr by the current diameter D of the machine roll 6. In most preferred embodiments of the present invention, the circumferential force applied to the fiber web on the surface of the machine reel is in the range of 0 to 500 N / m, preferably most likely 150 to 300 N / m.

From the sequence steps of the retractor, it is preferable that the primary nip NP and the secondary nip NS are arranged to load different machine rolls 6 during replacement. With the retractors 1 of the present invention, particularly for smooth and slippery fiber web types, it is important . In this case, the secondary nip roll 18 is preferably loading the completed machine roll 6 in the braking step, whereas the newly started rewinding of the next machine roll 6 is initially performed only by the primary nip forming roller 10. The hard surface winding cylinder, which can be further increased by grip, perforation, and / or carbide coating, if required, provides sufficiently tight reeling of the bottom of the roll so that interlayer slippages resulting in winding defects are prevented. The roll of the machine roll bottom region 25 is preferably rewound by centering torque,

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5 what low primary nipple load enhances.

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One particularly preferred application for the reel winder according to the invention is in the so-called wide fiber web lines, wherein the web has a width of about 10 m x or more, with large machine roll diameters over 2.8 m 30 (or slightly narrower machines over 3.2 m) and

when the boats exceed 1650 m / min. It is particularly advantageous to use a secondary nipple NS

c) increase the air removal from the machine roll 6 and the tightness of the surface rolls of the machine roll;

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As will be apparent to a person skilled in the art, the invention and its embodiments are not limited to the exemplary embodiments described above. The expressions in the claims 35 describing the existence of features, such as "secondary nip roll 18, 8 having a soft surface", are open so that the presentation of features does not exclude the existence of other features not set forth in the independent or independent claims.

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CD

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Reference numerals used in the drawings: 1 roller 10 winding cylinder 5 11 venting 111 groove width 112 groove depth 113 u limit 114 suction channel 10 18 secondary nip roll 181 secondary nip roll coating 5 reel roll 6 machine roll CL center line 15 H machine roll tension D to roll roll nip n

Te Rolling cylinder torque 20 Tr center drive torque

Ts is the torque W of the secondary nip roll of the fibrous web

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δ c \ j i m o i c \ j

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Claims (12)

A reeling device (1) for rolling up a fiber web (W) continuously around a tambour roll (5) to a machine reel (6), the reeling device (1) comprising a reeling cylinder (10) to form a primary type (NP) together with the machine roll (6) to be rolled and a secondary nip roll (18) to form a secondary nip (NS) together with the machine roll (6) to be rolled, characterized in that the roll-up cylinder (10) has a hard surface and Venta groove (11) , the Venta groove (11) comprises a circumferential groove in which the width of a groove is 2 ± 1 mm, the depth of a groove is 4 ± 2 mm and the gap distribution is 10 ± 5 mm, and the secondary groove roller (18) has a a soft surface (181), wherein an adhesion difference can be formed between the primary type (NP) and the secondary type (NS), such that the radial depression of the secondary polyp roller (18) in the machine roll (6) is less than the radial depression of the reel cylinder (10) with corresponding line load. 15 Winding device according to claim 1, characterized in that the secondary nip roll (18) has a soft surface where its hardness is 60-120 P&J, preferably 85-105 P&J. The reeling device according to claim 1, characterized in that the reeling device comprises means for oscillating the machine roller (6) to vary the position of the fiber web (W) in the y-direction in the machine roller (6). Roll-up device according to claim 1, characterized in that the distance between the primary type (NP) and the secondary type (NS) calculated according to the center angle (a) is greater than 60 degrees, preferably greater than 90 degrees. C \ J c3 Winding device according to claim 1, characterized in that the thickness of the soft coating (181) of the secondary type (18) is greater than or equal to 15 mm. ό 30 (M The reeling device according to claim 1, characterized in that the ratio of the diameter of the reeling cylinder (10) to the secondary nip roller (18) is c3 less than 2: 1. o CD σ> o ^ 35 A method for continuously rolling a fiber web (W) around a tambour roll (5) into a machine roll (6), wherein a primary type (NP) is formed with the reel cylinder (10) of the reel device (1) together with the machine reel to be reeled; and with the secondary nip roller (18), a secondary nip (NS) is formed together with the machine roll to be rolled, characterized in that with the hardened surface roll-up cylinder (10) and Venta groove (11) a primary elongation and a primary compression in the fiber web (W) are achieved. wherein, by means of the primary nip (NP), the majority of the interlayer air supplied with the fiber web (W) is removed, and with the secondary nip roller (18) having a soft surface, a secondary elongation and a secondary compression are obtained, whereby an adhesion difference can be formed between the primary nip (NP) and the secondary nip (NS), such that the radial depression of the secondary nip roller (18) in the machine roll (6) is smaller than the radius of the reel cylinder (10) la 10 lowering with corresponding line load. Method according to claim 7, characterized in that the ratio between the primary type (NP) and the secondary type (NS) to generate a rolling force is changed according to the nature of the fiber web. 15 Method according to claim 7, characterized in that by means of the torque of the reel cylinder (10) and the primary type (NP), more than 50% of the tension of the machine roller is formed. 20 Method according to claim 7, characterized in that the torque for central operation of the machine roller (6) and the secondary type (NS) forms almost 50% of the tension of the machine roller. Method according to claim 9 or 10, characterized in that the nip load of the primary nip (NP) is relatively less than the nip load of the secondary nip (NS), so that the fiber web layers at the primary nip can slide relative to each other in order to effect an elongation at least in the extreme. the fiber web layer of the machine roll. δ (M i 5) Method according to claim 7, characterized in that the reduced in circumferential force caused by the torque of the secondary nip roll (18) in the surface of the machine roll x (6) is greater than the reduced peripheral force caused by the torque of the reel cylinder (10) in the surface of the machine roll (6). 00 (M o CD CD o o {M