JP5288480B2 - Paper making method - Google Patents

Description

The present invention relates to the paper how. More specifically, it relates to as wet paper forming engineering to form a wet web from a pulp slurry of the papermaking process.

  2. Description of the Related Art Conventionally, a paper making apparatus is used that includes a wire having a paper making net formed into an annular endless track belt, and a plurality of wire rolls that are arranged so as to contact the wire and rotate as the wire travels. Yes.

  In such a papermaking apparatus, the wear of the wire is severe, and if the wire is frequently replaced, the productivity is remarkably lowered due to the operation stop due to the wire replacement.

  Therefore, as a measure to suppress the progress of wire wear and reduce the frequency of wire replacement, the progress of wire wear is suppressed by making paper by mixing silica sand with heavy calcium carbonate used as an internal filler. A technique is disclosed (for example, see Patent Document 1).

  Moreover, the technique which suppresses the abrasion progress of a wire is disclosed by making paper using the paper stock which added the alumina and the zirconia in the pulp slurry in which the filler was internally added (for example, refer patent document 2).

  Furthermore, paying attention to the fact that the ears of the wire on which the paper layer is not placed are more easily worn than other parts, a technique for suppressing the progress of wear of the wire by adding a wire life-extending agent to the ears of the wire that is easily worn. Is disclosed (for example, see Patent Document 3).

JP-A-8-144190 Japanese Patent Laid-Open No. 10-298894 JP 2007-16362 A

  However, since the method described in Patent Document 1 or 2 requires the addition of a filler to the pulp slurry, the wet paper containing the filler is affixed to the cylinder surface of the Yankee dryer. There was a risk of adverse effects.

  In the Yankee dryer, wet paper is pasted on the cylinder surface and dried, and a base paper (dried wet paper) is obtained by peeling from the cylinder surface while forming a crepe with a creping doctor. At this time, a coating agent is sprayed on the cylinder surface in order to make the peeling force (adhesive force) at which the base paper peels from the cylinder surface constant and to form a uniform crepe.

  However, when a filler is added to the pulp slurry, the wet paper containing the filler comes into contact with the cylinder surface, whereby the coating agent disappears, and the peeling force (adhesive force) may become uneven. In such a case, a uniform crepe cannot be formed on the base paper, resulting in deterioration of productivity and workability as well as deterioration of the base paper such as generation of dry spots, defects in the winding shape, and variations in paper quality. Is also undesirable. Moreover, there existed a problem that abrasion of the width direction side edge part (ear | edge part) of the wire in which a pulp slurry was not sprayed among wires could not be suppressed.

  Furthermore, the method described in Patent Document 3 has a problem that, of the wires, wear of the central portion in the width direction of the wire on which the pulp slurry is sprayed cannot be suppressed.

The present invention has been made in order to solve the problems of the prior art as described above, without mixing the filler into the pulp slurry or adding the wire life-extending agent to the wire. it is possible to suppress the wear progresses, there is provided a papermaking how it is possible to reduce the replacement frequency of the wire.

As a result of intensive studies to achieve the above problems, the inventors of the present invention have a wire that is a paper net on which pulp slurry is sprayed, and a contact portion (nip portion) of a wire roll that rotates with the traveling of the wire, It has been found that the above problem can be achieved by spraying water, and the present invention has been completed. According to the present invention, the following papermaking how is provided.

[1] Using a paper making apparatus comprising a wire having a paper making net formed in an annular endless track belt, and a plurality of wire rolls arranged so as to contact the wire and rotating as the wire travels, In the wet paper forming step of forming a thin layered wet paper by spraying a pulp slurry onto the surface of the wire and squeezing water contained in the pulp slurry from the mesh of the wire, the wire and the wire roll to the nip portion between while sprayed water entire width of the wire is run the wire, a paper making method to form a wet paper web, with spraying of water from the wire track upstream side with respect to the nip When the water is sprayed on the nip portion, the thickness of the wire is measured and the wire thickness in the width direction of the wire is measured. To thin regions, papermaking methods sprayed a large amount of water compared to other regions.

[2] Using a paper making apparatus comprising a wire in which a paper making net is formed into an annular endless track belt, and a plurality of wire rolls arranged so as to contact the wire and rotating as the wire runs, In the wet paper forming step of forming a thin layered wet paper by spraying a pulp slurry onto the surface of the wire and squeezing water contained in the pulp slurry from the mesh of the wire, the wire and the wire roll to the nip portion between while sprayed water entire width of the wire is run the wire, a paper making method to form a wet web, with spraying of water from the wire track upstream side with respect to the nip When the water is sprayed onto the nip portion, the dryness of the wire is measured and the wire is dried in the width direction of the wire. Degrees with respect to a region having a high, papermaking methods sprayed a large amount of water compared to other regions.

Paper how the present invention is mixed and the filler to the pulp slurry, without the addition of wires prolonging agent to the wire, it is possible to suppress the wear progress of the entire wire, to reduce the replacement frequency of the wire be able to. Therefore, the operation stop time due to the replacement of the wire can be reduced, and the production efficiency can be improved.

It is process drawing which shows typically one Embodiment of the papermaking method and papermaking apparatus of this invention. It is a side view which shows typically the shower used in the papermaking method and papermaking apparatus shown in FIG.

  Hereinafter, embodiments for carrying out the papermaking method and the papermaking apparatus of the present invention will be specifically described with reference to the drawings. However, the present invention broadly includes a papermaking method and a papermaking apparatus having the invention-specific matters, and is not limited to the following embodiments.

[1] Features of the papermaking method of the present invention:
As shown in FIG. 1, the paper making method of the present invention is a wet paper forming process 50 in which the wire 2 is applied to the nip portion between the wire 2 and the wire roll 4 while spraying water 6 over the entire width direction of the wire 2. It is characterized in that the wet paper 10 is formed by running.

  By running the wire 2 while spraying water 6 against the nip portion between the wire 2 and the wire roll 4, without adding a filler into the pulp slurry 9 or adding a wire life-extending agent to the wire 2. The wear of the wire 2 can be suppressed.

  In addition, by running the wire 2 while spraying the water 6 over the entire width direction of the wire 2, unlike the case of adding a filler to the pulp slurry 9 or adding a wire life-extending agent to the wire 2, Wear of the wire 2 can also be suppressed over the entire width direction.

  Thus, according to the papermaking method of the present invention, the frequency of replacing the wire 2 is reduced, and the operation stop time due to the replacement of the wire 2 is also reduced, so that the papermaking production efficiency can be improved.

[2] Configuration of the papermaking method and papermaking apparatus of the present invention:
The papermaking method of the present invention includes a wet paper sheet forming process for forming a thin wet paper sheet from pulp slurry as an essential process, and includes a dehydration process, a drying process, a calendering process, a winding process and the like as necessary. Hereinafter, it demonstrates for every process.

[2-1] Wet paper forming step:
As shown in FIG. 1, the wet paper web forming process 50 is a process of forming the thin lamellar wet paper paper 10 by squeezing the water contained in the pulp slurry 9.

  As the pulp slurry, for example, water, various additives (for example, deinked waste paper pulp obtained by deinking chemical pulp obtained from hardwood, softwood, newspaper waste, high quality waste paper, OA waste paper, etc.) , Dyes, wet paper strength enhancers, dry paper strength agents, pitch control agents, slime control agents, etc.) can be added to form a slurry.

  As shown in FIG. 1, the squeezing of the water contained in the pulp slurry 9 is arranged so as to abut the wire 2 in which the papermaking net is configured as an annular endless track belt. It can carry out using the papermaking apparatus 1 provided with the several wire roll 4 which rotates. The part constituted by the wire 2 and the wire roll 4 in the paper making apparatus 1 is referred to as a wire part 40. The wet paper web forming process 50 is performed in the wire part 40.

  Specifically, the pulp slurry 9 is sprayed on the surface of the wire 2, and water contained in the pulp slurry 9 is squeezed from the mesh of the wire 2. The pulp slurry 9 is sprayed thinly on the surface of the wire 2 configured in a mesh shape, and the moisture contained in the pulp slurry 9 is removed from the mesh of the wire 2, so that the moisture contained in the pulp slurry 9 is squeezed, and the lamellar layer The wet paper 10 is formed.

  For example, as shown in FIG. 1, the spraying of the pulp slurry 9 can be performed using a head box 8 (also referred to as “flow box” or “stuff box”). The head box 8 is a device that rectifies the pulp slurry 9 and sprays it on the surface of the wire 2 at a desired thickness, width, and speed. As the head box, for example, a conventionally known head box such as an open type, a sealed air pressure type, and a hydraulic type can be used.

  The wire 2 is formed by forming a net-like body (paper netting) made of, for example, metal or plastic into an annular endless track belt. As the wire, for example, a conventionally known wire such as a long net type, a circular net type, or a twin wire type can be used.

  The wire 2 is caused to travel by a drive roll (a roll that rotates by itself and imparts a propulsive force to the wire) arranged so as to contact the wire 2. In the papermaking apparatus 1 shown in FIG. 1, the two felt rolls 24 a and 24 b are drive rolls, and the felt roll 24 a runs the wire 2. That is, the felt roll 24 a rotates and the rotational force is transmitted to the wire 2, so that a propulsive force is applied to the wire 2. As long as the driving roll can apply a propulsive force to the wire, the driving roll may not be in direct contact with the wire but may be in contact with the wire via another member or the like. In the illustrated example, a felt roll 24 a that is a drive roll is in contact with the wire 2 via the dryer felt 22 and the wet paper 10. That is, this is an example in which all of the wire rolls 4 are driven rolls (rotation of the drive roll, roll that rotates following the progress of the wire 2). However, all or some of the plurality of wire rolls 4 may be drive rolls.

  In the paper making method of the present invention, as shown in FIG. 1, the wire 2 is caused to travel while spraying water 6 over the entire width direction of the wire 2 against the nip portion between the wire 2 and the wire roll 4, and the wet paper 10 Form. The “nip portion” means a contact portion between the wire 2 and the wire roll 4, and “the entire width direction” means not only the central portion in the width direction of the wire 2 on which the pulp slurry 9 is sprayed, but also pulp slurry. 9 also includes both side edges (referred to as “ear parts”) in the width direction of the wire 2 to which 9 is not sprayed.

  As the wire continues to be used, it may deteriorate and curl both sides. When the wire is run in this state, both side edges of the wire float from the surface of the wire roll and slip, and the wire is easily worn. The papermaking method of the present invention can suppress wear at both side edges in the width direction of the wire as well as at the center in the width direction of the wire, which is in strong contact with the wire roll and easily wears.

  There is no particular limitation on the method of spraying water on the nip portion. However, as shown in FIG. 1, it is preferable to spray water 6 using a shower 12. According to the shower 12, a sufficient amount of water can be sprayed with a simple device.

  In the paper making method of the present invention, it is preferable to spray water from the upper side of the wire track river to the nip portion. For example, as shown in FIG. 1, the shower 12 is disposed on the upper side of the runway of the wire 2 with respect to the nip portion. By spraying the water 6 from the upper side of the runway river of the wire 2, the water 6 enters the nip portion as the wire 2 travels, and the effect of spraying the water 6 can be sufficiently obtained.

  In addition, “the river upper side of the wire runway” means the position between the wire roll to be sprayed with water and the wire roll that is adjacent to the wire roll and installed on the river upper side of the wire runway. To do. Especially, it is more preferable to spray water from the vicinity of the wire roll used as the object to spray water.

  In the paper making method of the present invention, when water is sprayed on the nip portion, it is preferable to spray a larger amount of water on a specific region in the width direction of the wire than on other regions. That is, it is preferable not to spray a uniform amount of water over the entire width direction of the wire but to make a difference in the amount of water sprayed in the width direction of the wire. By such a method, water can be preferentially sprayed on a portion where the wire is heavily worn, and the wire wear can be more efficiently suppressed.

  Specifically, it is preferable to measure the thickness of the wire, and to spray a larger amount of water to the region where the wire thickness in the width direction of the wire is thinner than other regions. Since it is considered that the wear of the wire is progressing in the region where the wire thickness is thin, the progress of the wear in the region can be delayed by spraying a large amount of water onto the region. Examples of the portion where the wire wears heavily include the width direction edge region of the wire where wear due to slip is likely to occur.

  It is also preferable to measure the dryness of the wire and to spray a larger amount of water on the region where the wire dryness in the width direction of the wire is higher than other regions. A region with high dryness is most prone to wear and deterioration among wires. Therefore, wire wear and deterioration can be effectively suppressed by spraying a large amount of water onto the region. As a part with a high dryness of a wire, the width direction side edge area | region (ear part) of the wire in which a pulp slurry is not sprayed can be mentioned, for example.

  The dryness of the wire also changes while the wire is running. For example, as shown in FIG. 1, after the wire 2 passes through the wire roll 4a, the wet paper 10 already containing moisture has been transferred to the dryer felt 22, so that the dryness of the wire 2 is increased. Therefore, in the paper making method of the present invention, it is also preferable to spray water 6 on the wire 2 at a portion where the dryness of the wire 2 is high in the running path of the wire 2.

  In the papermaking apparatus 1 shown in FIG. 1, the shower 12 is installed on the upper side of the wire roll 4b and the wire roll 4c, and water 6 is sprayed onto the wire 2 at the subsequent stage of the wire roll 4a where the dryness of the wire 2 is increased. It is configured as follows.

  In addition, the dryness (it is also called "carry back") of the wire 2 collects the water | moisture content adhering to the outer surface of a wire, or contained in the inside of a wire with the following method, and measures the moisture content. Can be done. Specifically, first, an air nozzle having a predetermined orifice diameter is installed at a position away from the wire by a predetermined distance on the back surface side (inner track inner peripheral side) of the wire. Next, air is blown from the air nozzle to the wire with a predetermined pressure, and the water adhering to the outer surface of the wire or contained in the wire is recovered. The dryness of the wire can be measured by weighing the amount of water collected per unit time.

  Although the amount of water spraying is not particularly limited, it may be determined as needed and is not particularly limited. Usually, a shower nozzle having a discharge amount of 0.2 to 100 L / hour is used. Therefore, it may be determined appropriately within this range.

  In order to spray water over the entire width direction of the wire, the shower preferably has a plurality of shower nozzles arranged in the width direction of the wire. Rather than spraying water from a single shower nozzle, it becomes possible to spray water uniformly over the entire width direction of the wire. The shape of the shower nozzle is not particularly limited, and a conventionally known one can be used. Examples of the shape include a flat nozzle and a full cone (tubular shape).

  As shown in FIG. 2, when the shower 12 has a plurality of shower nozzles 14, a valve 16 that adjusts the amount of water supplied to the shower nozzle 14 is attached to the front of the shower nozzle 14. It is further preferable that In this way, by attaching the valve 16 to each shower nozzle 14, the amount of water sprayed can be changed for each shower nozzle 14. For example, with respect to the amount of water sprayed in the central region in the width direction of the wire, the amount of water sprayed in the region on both sides in the width direction of the wire can be increased extremely simply.

  As shown in FIG. 2, the shower 12 is configured as a multi-port shower 20 in which a plurality of shower nozzles 14 are integrated so that water can be sprayed over the entire width direction of the wire. The shower 12 preferably includes an actuator that reciprocates the multi-mouth shower 20 in the wire width direction (the direction of arrow W in FIG. 2). According to such a configuration, even if the number of shower nozzles 14 is small, water can be sprayed evenly over the entire width direction of the wire. The multi-mouth shower 20 shown in FIG. 2 is configured integrally by attaching a plurality of shower nozzles 14 to a single pipe 18.

  The type of the actuator is not particularly limited as long as the multi-mouth shower can be reciprocated in the width direction of the wire. For example, a servo motor, a hydraulic cylinder, a pneumatic cylinder, a hydraulic motor, etc. can be mentioned.

[2-2] Dehydration step:
As shown in FIG. 1, the dehydration step 52 is a step of further removing the moisture of the thin layered wet paper 10 formed in the wet paper forming step 50.

  As shown in FIG. 1, the moisture in the wet paper 10 is removed by arranging the felt as an annular endless track belt, the dryer felt 22 and the dryer felt 22, and rotating as the dryer felt 22 travels. , And a plurality of felt rolls 24 can be used. In the paper making apparatus 1, a part constituted by the dryer felt 22 and the felt roll 24 is referred to as a press part 42. The dehydration process 52 is performed in the press part 42. Specifically, the wet paper 10 fed from the wire part 40 is placed on the surface of the dryer felt 22, and the moisture contained in the wet paper 10 is further removed through the fibrous dryer felt 22.

[2-3] Drying step:
As shown in FIG. 1, the drying step 54 is a step of drying the wet paper 10 from which moisture has been removed in the dehydration step 52.

  As shown in FIG. 1, the wet paper 10 can be dried by a paper making apparatus provided with a cylindrical dryer cylinder 26. In the papermaking apparatus 1, a portion where the dryer cylinder 26 is disposed is referred to as a dry part 44. The drying process 54 is performed in the dry part 44.

  Specifically, the wet paper 10 from which moisture has been removed in the dehydration step 52 is pressed against the outer peripheral surface of the dryer cylinder 26 in a heated state, and further, the outer periphery of the dryer cylinder 26 from an injection port installed inside the hood 28. The wet paper 10 is dried by spraying hot air on the side, and the base paper 31 is obtained. Although the kind of dryer is not specifically limited, For example, a Yankee dryer etc. can be used suitably.

[2-4] Calendar processing step:
As shown in FIG. 1, the calendering process 56 is a process of calendering the base paper 31 obtained by drying the wet paper 10 in the drying process 54.

  The calendering can be performed by a paper making apparatus including a calendar roll 30 and a receiving roll 32 as shown in FIG. In the paper making apparatus 1, a part constituted by the calendar roll 30 and the receiving roll 32 is referred to as a calendar part 46. The calendar processing step 56 is performed in this calendar part 46.

  Specifically, the base paper 31 obtained by drying the wet paper 10 in the drying step 54 is sandwiched between the calender roll 30 and the receiving roll 32 and pressed to smooth the surface of the base paper 31 and the structure is dense. , Uniform paper thickness, and gloss.

  Although the kind of calendar roll 30 is not specifically limited, For example, a metal roll etc. can be used suitably.

[2-5] Winding process:
As shown in FIG. 1, the winding process 58 is a process of winding the base paper 31 that has been subjected to the calendar process in the calendar process 56.

  The winding can be performed by a paper making apparatus provided with a reel 34 as shown in FIG. In the papermaking apparatus 1, a portion where the reel 34 is disposed is referred to as a reel part 48. The winding process is performed in the reel part 48.

  Specifically, the base paper 31 that has been calendered in the calendar processing step 56 is fixed to a winding core attached to the reel 34, and the reel 34 is rotated to wind the base paper 31 around the winding core 38. At this time, winding is performed so that the surface (smooth surface) attached to the surface of the dryer cylinder 26 of the wet paper 10 faces the outside of the roll. Thereby, the base paper roll 36 by which the base paper 31 was wound up by roll shape can be obtained.

Paper how the present invention, tissue paper, paper towels such as kitchen paper, sheet-like toilet paper, can be suitably used for production of sanitary paper, such as wax coating (Kamiwata).

1: Paper machine, 2: Wire, 4, 4a, 4b, 4c: Wire roll, 6: Water, 8: Head box, 9: Pulp slurry, 10: Wet paper, 12: Shower, 14: Shower nozzle, 16: Valve: 18: pipe, 20: multi-mouth shower, 22: dryer felt, 24, 24a, 24b: felt roll, 26: dryer cylinder, 28: hood, 30: calendar roll, 31: base paper, 32: receiving roll, 34 : Reel, 36: base paper roll, 38: core, 40: wire part, 42: press part, 44: dry part, 46: calendar part, 48: reel part, 50: wet paper forming process, 52: dewatering process, 54: drying process, 56: calendaring process, 58: winding process.

Claims (2)

Using a paper making apparatus comprising a wire configured with an annular endless track belt and a plurality of wire rolls arranged so as to contact the wire and rotating as the wire runs,
In the wet paper forming step of forming a thin layered wet paper by spraying the pulp slurry on the wire surface and squeezing the water contained in the pulp slurry from the mesh of the wire,
For the nip portion between the wire and the wire roll, a papermaking method for forming the wet paper by running the wire while spraying water over the entire width direction of the wire ,
A region where the wire thickness is thin in the width direction of the wire when water is sprayed onto the nip portion from the upper side of the wire runway and water is sprayed onto the nip portion. On the other hand, a papermaking method in which a large amount of water is sprayed compared to other areas . Using a paper making apparatus comprising a wire configured with an annular endless track belt and a plurality of wire rolls arranged so as to contact the wire and rotating as the wire runs,
In the wet paper forming step of forming a thin layered wet paper by spraying the pulp slurry on the wire surface and squeezing the water contained in the pulp slurry from the mesh of the wire,
For the nip portion between the wire and the wire roll, a papermaking method for forming the wet paper by running the wire while spraying water over the entire width direction of the wire,
With spraying water from pairs Shi Wa ear runway upstream side to the nip portion, when spraying water against the nip portion, by measuring the dryness of the wire, the wire dryness in the width direction of the wire A papermaking method in which a large amount of water is sprayed on a high area compared to other areas .

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