JP2016141890A - Papermaking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a papermaking device capable of smoothly converting a wet paper, which is obtained by dehydrating a paper stuff liquid on a papermaking mold, to felt, feeding the felt to a next process and efficiently and stably making paper.SOLUTION: A papermaking device 10 according to this invention comprises: a cylinder mold suction cylinder 12; a head box 11, which supplies a paper stuff liquid to a periphery 120 of the cylinder mold suction cylinder 12; and an endless felt 14A, which is disposed across multiple guide rolls 13. Only one of the multiple guide rolls 13 is a couch roll 13A, which is disposed so as to contact the periphery 120 by being pressed against the periphery. The endless felt 14A is overlaid on wet paper WP on the periphery 120 between the cylinder mold suction cylinder 12 and the couch roll 13A, while the endless felt 14A is not overlaid on the wet paper WP on the periphery 120 upstream a section between the cylinder mold suction cylinder 12 and the couch roll 13A in a rotation direction R1 of the cylinder mold suction cylinder 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a paper machine suitable for a paper machine, particularly a circular paper machine.

  Conventionally, sanitary thin paper such as towel paper, tissue paper, toilet paper, and napkin has been manufactured by a wet papermaking method using various paper machines. For example, Patent Document 1 describes that a paper sheet such as towel paper or toilet paper is manufactured using a circular net paper machine, and specifically, an outer periphery of a circular net that is driven to rotate around an axis. The paper liquid is supplied to the section, and the paper liquid is moved along with the rotation of the circular net while the water of the paper liquid is discharged into the circular net to proceed with the dehydration. Describes a method of manufacturing a paper sheet through a wire part that transfers the wet paper formed by the process to felt.

  FIG. 3 shows an example of a paper making apparatus conventionally used for paper making such as sanitary thin paper. A paper machine 90 shown in FIG. 3 has a basic configuration similar to that of the circular net paper machine shown in FIG. 2 of Patent Document 1, and has a cylindrical shape that rotates around the central axis in the direction indicated by reference numeral R1 in FIG. A circular net suction cylinder 91, a head box 92 for supplying a stock liquid to the outer peripheral portion 910 of the circular net suction cylinder 91, and a plurality of cylindrical guide rolls 93a, 93b, 93c rotatably supported. An endless felt 94 that runs over a running path defined by the plurality of guide rolls 93a to 93d, and supplies the stock liquid from the head box 92 to the outer peripheral portion 910 to provide the wet paper WP. The wet paper WP is transferred from the outer peripheral portion 910 to the endless felt 94 and conveyed to the next process. In the papermaking apparatus 90, two guide rolls 93b and 93c out of a plurality of guide rolls 93a to 93d that span the endless felt 94 are arranged so that the outer peripheral portion 910 of the circular net suction cylinder 91 can be pressed. . Therefore, the endless felt 94 travels in the circumferential direction of the circular mesh suction cylinder 91 while being pressed against the wet paper WP on the outer peripheral portion 910 of the circular mesh suction cylinder 91 while traveling between both guide rolls 93 b and 93 c.

JP 2006-320625 A

When wet papermaking is performed using the conventional papermaking apparatus 90 shown in FIG. 3, the wet paper WP on the outer circumference of the circular net suction cylinder 91 is originally between the circular net suction cylinder 91 and the guide roll 93c. Where the endless felt 94 that should have passed should be transferred to the circular suction cylinder 91 side without success, and as a result, the operation of the paper making apparatus 90 is stopped, resulting in a decrease in paper manufacturing efficiency. There was a problem of inviting significantly. According to the knowledge of the present inventors, this problem of lowering the transferability of wet paper occurs frequently especially when paper with a relatively high basis weight having a basis weight of 30 g / m ² or more is made.

  An object of the present invention relates to a papermaking apparatus that can smoothly transfer a wet paper obtained by dehydrating a stock solution on a papermaking net to a felt and send it to the next process, thereby enabling efficient and stable papermaking. .

  The present invention provides a cylindrical circular mesh suction cylinder whose outer peripheral portion is formed by a papermaking net and rotates around a central axis, a head box for supplying a stock liquid to the outer peripheral portion of the circular net suction cylinder, and a plurality of guides An endless felt that runs across a roll and that runs on a traveling path defined by a plurality of the guide rolls, and supplies the stock liquid from the head box to the outer periphery of the circular net suction cylinder. The moisture content of the stock liquid is reduced by suction from the inside of the cylinder to form a wet paper on the outer peripheral portion, the endless felt is stacked on the wet paper, and the wet paper is put on the endless portion from the outer peripheral portion. A papermaking apparatus that transfers to a felt and sends it to the next process, wherein only one of the plurality of guide rolls spanning the endless felt is the circular net suction cylinder It is a couch roll arranged so that the outer peripheral part can be pressed, and the wet paper web is transferred from the outer peripheral part to the endless felt at the closest part of the couch roll to the circular net suction cylinder. The endless felt is stacked on the wet paper on the outer periphery of the circular net suction cylinder between the circular net suction cylinder and the couch roll, and more than between the circular net suction cylinder and the couch roll. On the upstream side in the rotation direction of the circular net suction cylinder, the paper making apparatus cannot be overlaid on the wet paper on the outer periphery of the circular net suction cylinder.

  According to the present invention, there is provided a papermaking apparatus capable of smoothly transferring wet paper obtained by dehydrating a stock solution on a papermaking net to a felt and sending it to the next process, and efficiently and stably making paper. Provided.

FIG. 1 is an overall schematic view of an embodiment of a paper making apparatus according to the present invention. FIG. 2 is a schematic view of a main part of the paper making apparatus shown in FIG. 1, that is, a circular net suction cylinder and its peripheral part. FIG. 3 is a schematic view of a circular net suction cylinder and its peripheral part in a conventional papermaking apparatus.

  Hereinafter, a paper making apparatus of the present invention will be described based on preferred embodiments with reference to the drawings. 1 and 2 show a paper making apparatus 10 according to the present embodiment. The papermaking apparatus 10 has an outer peripheral portion 120 formed of a papermaking net, and a cylindrical circular net suction cylinder 12 that rotates in the direction indicated by reference numeral R1 in FIG. A head box 11 and an endless felt 14A that travels on a traveling path defined by the plurality of guide rolls 13 and spans the plurality of cylindrical guide rolls 13. A liquid stock is supplied to the outer peripheral portion 120 of the sheet, and a wet paper WP is formed on the outer peripheral portion 120 by reducing the water content of the stock liquid by suction from the inner side of the circular net suction cylinder 12. The endless felt 14A is overlapped on the wet paper WP, and the wet paper WP is transferred from the outer peripheral portion 120 to the endless felt 14A and sent to the next process.

  More specifically, as shown in FIG. 1, the paper making apparatus 10 includes a wire part portion 10 </ b> A that forms the stock liquid supplied from the head box 11 on the wet paper WP on the outer peripheral portion 120 of the circular net suction cylinder 12; A press part 10B that transfers the wet paper WP on the outer periphery 120 to the endless felt 14A and squeezes it, a dryer part 10C that dries the wet paper WP to make the paper DP, and a reel part that winds the paper DP 10D.

  The wire part portion 10 </ b> A includes a head box 11 and a circular net suction cylinder 12. As shown in FIG. 2, the head box 11 has a supply port 110 for ejecting the stock liquid, and the supply port 110 is located at the closest part of the head box 11 to the circular net suction cylinder 12. Further, the head box 11 extends from the supply port 110 position along the outer peripheral portion 120 of the circular net suction cylinder 12 to the downstream side in the rotation direction R1 and covers the outer peripheral portion 120 with a predetermined gap, and the supply port 110. And a lower lip 112 disposed on the upstream side in the rotation direction R1, and the both lips 111, 112 define a flow path of the stock liquid ejected from the supply port 110. The circular mesh suction cylinder 12 receives power from a motor (not shown) such as a motor and rotates around the central axis in the direction of arrow R1. The outer peripheral portion 120 of the circular net suction cylinder 12 is made of a cylindrical body formed by weaving a metal wire or a synthetic resin wire into a cylindrical shape. As the wire, what is usually used for this type of suction cylinder is used. It can use without a restriction | limiting especially, The mesh size of this wire can be selected suitably.

  A couch roll 13A, which is one of a plurality of guide rolls 13 spanning the endless felt 14A, is located downstream of the position corresponding to the supply port 110 in the outer peripheral portion 120 of the circular net suction cylinder 12 in the rotational direction R1. However, it arrange | positions so that the outer peripheral part 120 can be press-contacted. Among the plurality of guide rolls 13, only the one couch roll 13 </ b> A is disposed so that the outer peripheral portion 120 can be pressed. The couch roll 13A receives power from a motor (not shown) such as a motor and rotates around the central axis in the direction of arrow R2. The diameter of the couch roll 13 </ b> A is larger than the diameter of the other guide rolls 13, but smaller than the diameter of the circular net suction cylinder 12. The ratio between the diameter of the couch roll 13A and the diameter of the circular net suction cylinder 12 is preferably 0.50 or more, more preferably 0.55 to 1.00, and even more preferably 0.70 to 1.. 00.

  The wet paper web WP on the outer peripheral portion 120 of the circular mesh suction cylinder 12 is transferred from the outer peripheral portion 120 to the endless felt 14A at the closest part of the couch roll 13A to the circular mesh suction cylinder 12. The closest part is the transfer position of the wet paper WP. The upper lip 111 of the head box 11 described above does not extend to the transfer position of the wet paper web WP, but extends to a substantially intermediate position between the transfer position and the supply port 110.

  As shown in FIG. 2, the inside of the circular net suction cylinder 12 has a range in the rotational direction R1 from the position corresponding to the supply port 110 of the head box 11 to the transfer position of the wet paper web WP. It is partitioned into a plurality of independent space portions 12A, 12B, 12C. The space portions 12A, 12B, and 12C are each connected to a vacuum suction pump (not shown) via a valve (not shown), and the suction force of the space portions 12A, 12B, and 12C is independently adjusted by the opening degree of the valve. It has been made possible.

  In the wire part portion 10A, the stock liquid is supplied from the supply port 110 of the head box 11 to the outer peripheral portion 120 of the circular net suction cylinder 12 in a state in which the circular net suction cylinder 12 is rotationally driven in the direction indicated by R1. . The stock liquid supplied to the outer peripheral portion 120 is dehydrated by suction from the inside of the circular mesh suction cylinder 12 in the process of moving along with the rotation of the circular mesh suction cylinder 12, and when the dehydration proceeds to a certain extent, A wet paper web WP is formed on the outer periphery 120. The suction force by the circular net suction cylinder 12 effectively acts on the stock liquid due to the presence of the upper lip 111, thereby promoting the dehydration of the stock liquid. In the circular net suction cylinder 12, suction may be performed in all of the space portions 12A, 12B, and 12C, and suction is performed only in a part of the plurality of space portions, for example, the space portions 12A and 12B. Natural suction may be performed at the transfer position of the wet paper web WP corresponding to the space portion 12C and in the vicinity thereof without performing suction.

  The press part 10B squeezes and dehydrates the wet paper WP formed in the wire part 10A to form a wet paper WP having a lower water content. As shown in FIG. It includes endless felts 14A and 14B that are stretched over and a pair of press rolls 15a and 15b. The press part 10B includes two types of endless felts 14A and 14B having different traveling paths. The endless felt 14 </ b> A is a so-called pickup felt that is stretched over a couch roll 13 </ b> A that is arranged so that the outer peripheral portion 120 of the circular net suction cylinder 12 can be pressed, and that transfers the wet paper WP from the outer peripheral portion 120. It is introduced between the press rolls 15a and 15b together with the WP. On the other hand, the endless felt 14B is not stretched over the couch roll 13A, travels on a different travel path from the endless felt 14A, and is introduced between the press rolls 15a and 15b. The endless felts 14A and 14B may have basic functions such as squeezing water from the wet paper, smoothness to improve the smoothness of the wet paper, and wet paper transport properties for transporting the wet paper. An endless felt generally used in various types of papermaking machines can be used without any particular limitation. For example, a base made of woven fabric and the like, and staple fibers entangled and integrated with the base by a needle punch A felt including a layer is mentioned.

  In the press part 10B, as shown in FIG. 1 and FIG. 2, the wet paper WP on the outer periphery 120 of the circular mesh suction cylinder 12 is endlessly felt at the closest part to the circular mesh suction cylinder 12 of the couch roll 13A. 14A, the wet paper WP and the endless felt 14A are integrated into an integrated product 20, and the integrated product 20 is introduced between the pair of press rolls 15a and 15b. The endless felt 14B is introduced between the press rolls 15a and 15b together with the integrated product 20, and the wet paper WP in the integrated product 20 is pressed and squeezed by the press rolls 15a and 15b while being sandwiched between the endless felts 14A and 14B. . The wet paper WP squeezed in this manner adheres to the endless felt 14B to form an integrated product 21, and is conveyed to the dryer part 10C together with the endless felt 14B. On the other hand, the endless felt 14A moves away from the wet paper web WP and travels along a predetermined traveling path toward the couch roll 13A again.

  As shown in FIG. 1, the dryer part section 10 </ b> C includes a Yankee dryer 16 that is a rotary cylinder type paper machine dryer. In the dryer part unit 10 </ b> C, one side of the wet paper WP is closely dried on the peripheral surface of the cylindrical Yankee dryer 16 to form the paper DP, and then the paper DP is peeled off from the Yankee dryer 16 using the doctor blade 17. At that time, the paper DP may be creped by the doctor blade 17 on the Yankee dryer 16 by a known method. The paper DP obtained by the dryer part 10C is wound in a roll shape by the reel part 10D. Thereafter, the paper DP can be subjected to various known processes such as cutting and calendaring as necessary.

  As one of the main features of the paper making apparatus 10 of this embodiment, as shown in FIG. 2, an endless felt 14A (pickup felt) is provided between the circular net suction cylinder 12 and the couch roll 13A. The wet paper web WP on the outer peripheral portion 120 is overlaid on the wet paper web WP on the outer peripheral portion 120 on the upstream side in the rotational direction R1 from between the circular suction cylinder 12 and the couch roll 13A. . Here, “between the circular mesh suction cylinder 12 and the couch roll 13A” means the normal line NL of the couch roll 13A at the closest part (transition position of the wet paper web WP) with the circular mesh suction cylinder 12 of the couch roll 13A, This is a region sandwiched between the tangent line TL of the couch roll 13A that is parallel to the line NL and located on the upstream side in the rotational direction R1 of the circular net suction cylinder 12.

Thus, the timing at which the endless felt 14A is superimposed on the wet paper WP on the outer peripheral portion 120 of the circular mesh suction cylinder 12 is limited to the timing at which the wet paper WP exists between the circular mesh suction cylinder 12 and the couch roll 13A. Thus, the wet paper web transfer failure, which has been a problem in the conventional circular paper machine as shown in FIG. 3, is effectively prevented. Therefore, the wet paper web WP is smoothly transferred to the endless felt 14A and sent to the next process. This enables efficient and stable papermaking. In the conventional circular net paper machine, the wet paper transfer failure is particularly frequent in the case of making a relatively high basis weight paper having a basis weight of 30 g / m ² or more. the amount 30 g / m ² or more, preferably 35~100g / m ^2, more preferably useful for paper making of paper 35~70g / m ^2.

When paper with a basis weight of 30 g / m ² or more is made on a conventional circular paper machine, the wet paper does not transfer to the felt at the closest part to the circular mesh suction cylinder of the couch roll, and the circular mesh suction cylinder The reason for remaining on the outer periphery is not clear, but is presumed as follows. In other words, in order to smoothly transfer the wet paper to the felt, it is necessary for the wet paper to have a proper paper strength (such as stiffness) while maintaining the wet state at the transfer position. For this purpose, the moisture content of the wet paper must be within a certain range at the transition position. The moisture content of the wet paper web present on the outer periphery of the circular net suction cylinder can be adjusted by adjusting the suction force of the circular net suction cylinder as appropriate. As a result, the suction force of the circular net suction cylinder decreases, and it becomes difficult to adjust the moisture content of the wet paper by the suction force. In the conventional paper making apparatus 90 shown in FIG. 3, the endless felt 94 has an outer periphery of the circular net suction cylinder 91 on the upstream side in the rotational direction R1 from between the circular net suction cylinder 91 and the guide roll 93c (coach roll). The endless felt 94 is overlapped on the wet paper WP on the outer peripheral portion 910 at a timing earlier than that of the papermaking apparatus 10 shown in FIG. 2, and the endless felt 94 and the outer peripheral portion 910 are overlapped with each other. The state where the wet paper web WP overlaps is maintained for a relatively long time. Therefore, in the papermaking apparatus 90, the dewatering of the wet paper WP due to the suction of the circular net suction cylinder 91 is difficult to proceed, and the wet paper WP on the outer peripheral portion 910 overlaps the endless felt 94 in a state containing an excessive amount of moisture. As it is, it is transferred to the transition position (the closest part of the guide roll 93c to the circular net suction cylinder 91), and part of the moisture in the wet paper WP is absorbed by the endless felt 94 during the transfer. At the transition position, the moisture absorbed from the wet paper WP and contained in the endless felt 94 is squeezed out by the guide roll 93c, and the squeezed water is absorbed by the wet paper WP by suction by the circular net suction cylinder 91. Therefore, the paper strength of the wet paper WP is reduced, and as a result, the wet paper WP does not transfer to the endless felt 94 and the wet paper WP remains on the outer peripheral portion 910.

  In contrast, the paper making apparatus 10 of the present embodiment has a timing at which the endless felt 14A is superimposed on the wet paper WP on the outer peripheral portion 120 of the circular net suction cylinder 12, and the wet paper WP is connected to the circular net suction cylinder 12 and the couch roll 13A. Since the wet paper WP alone can be maintained on the outer peripheral portion 120 for a longer time than the conventional paper making apparatus, the suction force of the circular net suction cylinder 12 is adjusted. The moisture content of the wet paper web WP can be easily adjusted by the wet paper web WP, and the wet paper web WP smoothly transfers from the outer peripheral portion 120 to the endless felt 14A at a predetermined transfer position (the closest portion of the couch roll 13A to the circular net suction cylinder 12). obtain.

  From the viewpoint of ensuring the above-described effects, the endless felt 14A is disposed on the wet paper WP on the outer peripheral portion 120 of the circular net suction cylinder 12 between the circular net suction cylinder 12 and the couch roll 13A. Assuming that the endless felt 14A is overlapped, the endless felt 14A is within 150 mm along the rotational direction R1 upstream of the rotational direction R1 from the closest part (the transfer position of the wet paper web WP) with the circular net suction cylinder 12 of the couch roll 13A. In particular, it is preferable to overlap the wet paper WP on the outer peripheral portion 120 of the circular net suction cylinder 12 in an area within 70 mm, particularly within 30 mm.

  In the papermaking apparatus 10 of the present embodiment, as shown in FIG. 2, the endless felt 14A is tangential to the couch roll 13A at the closest part (the transfer position of the wet paper WP) to the circular net suction cylinder 12 of the couch roll 13A. And is introduced between the circular net suction cylinder 12 and the couch roll 13A. Therefore, the endless felt 14A and the wet paper WP on the outer peripheral portion 120 are overlapped at the transfer position of the wet paper WP or in the vicinity thereof in the paper making apparatus 10 of the present embodiment. With such a configuration, in the paper making apparatus 10, moisture in the wet paper WP is absorbed by the endless felt 14 </ b> A superimposed on the wet paper WP at an early stage before the wet paper WP on the outer peripheral portion 120 reaches the transfer position. Therefore, the above-described transfer of moisture from the endless felt 14A to the wet paper WP at the transfer position is suppressed, and the transfer of the wet paper WP to the endless felt 14A is smoothly performed.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention. For example, the position, shape, and length of the upper lip 111 and the lower lip 112 of the head box 11 are appropriately adjusted according to the paper material liquid ejected from the supply port 110, its pressurizing condition, the suction force of the circular net suction cylinder 12, etc. Is done. Further, the dryer part section 10C is not limited to a Yankee dryer as shown in the figure, and may include a drying means that is usually employed in this type of paper making apparatus. The papermaking apparatus of the present invention can be used for manufacturing various types of paper, and is particularly suitable for manufacturing sanitary thin paper such as towel paper, tissue paper, toilet paper, and napkin.

10, 90 Papermaking apparatus 10A Wire part 10B Press part 10C Dryer part 10D Reel part 11, 92 Head box 110 Supply port 111 Upper lip 112 Lower lip 12,91 Circular suction cylinders 12A, 12B, 12C Circular suction Cylinder inner space 120, 910 Circular net suction cylinder outer peripheral part 121 Partition plate 13, 93a, 93b, 93c, 93d Guide roll 13A Couch roll 14A, 14B, 94 Endless felt 15a, 15b Press roll 16 Yankee dryer 17 Doctor blade 20, 21 Integrated product of wet paper and endless felt WP Wet paper DP paper (dried wet paper)

Claims (4)

A cylindrical circular mesh suction cylinder whose outer peripheral part is formed by a papermaking net and rotates around the central axis, a head box that supplies the stock liquid to the outer peripheral part of the circular net suction cylinder, and a plurality of guide rolls. And an endless felt that travels on a travel path defined by the plurality of guide rolls,
Supply the stock liquid from the head box to the outer periphery of the circular mesh suction cylinder, reduce the water content of the stock liquid by suction from the inner side of the circular mesh suction cylinder, and wet paper on the outer peripheral portion A papermaking apparatus for superimposing the endless felt on the wet paper, transferring the wet paper from the outer periphery to the endless felt, and sending it to the next process,
Only one of the plurality of guide rolls spanning the endless felt is a couch roll disposed so as to be able to press-contact the outer periphery of the circular net suction cylinder, and the couch roll is connected to the circular net suction cylinder. The wet paper web is transferred from the outer periphery to the endless felt at the closest part,
The endless felt is stacked on the wet paper on the outer periphery of the circular net suction cylinder between the circular net suction cylinder and the couch roll, and more than between the circular net suction cylinder and the couch roll. A papermaking apparatus that is not superposed on the wet paper on the outer periphery of the circular net suction cylinder on the upstream side in the rotational direction of the circular net suction cylinder.   The said endless felt is piled up on the said wet paper on the outer peripheral part of the said circular net suction cylinder in the area | region within 150 mm to the upstream of the rotation direction of the said circular mesh suction cylinder from the said nearest part. Paper machine.   The papermaking apparatus according to claim 1 or 2, wherein the endless felt travels along a tangential direction of the couch roll at the closest portion and is introduced between the circular net suction cylinder and the couch roll. The papermaking apparatus as described in any one of Claims 1-3 which papermaking paper with a basic weight of 30 g / m < ² > or more.

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