JP5777475B2 - Wet tissue manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a wet tissue.

  Two rolls are rolled out, the rolled-out rolls are folded, the folded rolls are impregnated with chemicals, the rolls impregnated with chemicals are stacked, and the stacked rolls are cut In the prior art, a wet tissue manufacturing method for manufacturing a wet tissue package is known by preparing wet tissues, laminating wet tissues, and packaging the laminated wet tissues (for example, Patent Document 1). ). Also known as a prior art is a wet tissue manufacturing method in which a continuously supplied raw material is impregnated with a chemical solution, cut to produce a wet tissue, the wet tissue is laminated, and the laminated wet tissue is further impregnated with the chemical solution. (For example, Patent Document 2).

Japanese Patent Application Laid-Open No. 2011-2601 JP-A-7-204118

  In order to improve the wiping performance of the wet tissue, a bulky wet tissue is desired.

The present invention employs the following configuration in order to solve the above problems.
That is, the present invention is a wet process including a step of preparing a fiber sheet, a step of folding the fiber sheet, a step of impregnating the fiber sheet with a chemical solution, a step of cutting the fiber sheet, and a step of laminating the fiber sheet. A method for producing a tissue, comprising a step of increasing the moisture content of a fiber sheet and a step of injecting high-pressure steam onto the fiber sheet having an increased moisture content, between the step of preparing the fiber sheet and the subsequent step. The step of increasing the moisture content of the fiber sheet includes increasing the moisture content of the fiber sheet on a suction drum, and the step of injecting the high-pressure water vapor injects high-pressure water vapor onto the fiber sheet on the suction drum. To do.

  According to the present invention, a bulky wet tissue can be produced.

FIG. 1 is a perspective view of a package in which a wet tissue manufactured by a wet tissue manufacturing method according to an embodiment of the present invention is packaged. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a perspective view showing the wet tissue in a folded state. FIG. 4 is an enlarged perspective view of a part of the wet tissue. FIG. 5 is a schematic diagram illustrating an example of a wet tissue manufacturing apparatus used in the wet tissue manufacturing method according to an embodiment of the present invention. FIG. 6 is a diagram showing an example of a spray used in the method for producing a wet tissue in one embodiment of the present invention. FIG. 7 is a diagram showing an example of a steam nozzle used in the method for producing a wet tissue in one embodiment of the present invention. FIG. 8 is a view for explaining the principle that fibers of a fiber sheet are loosened by high-pressure steam and the bulk of the fiber sheet becomes high. FIG. 9 is a schematic cross-sectional view in the width direction of a fiber sheet on which high-pressure steam is jetted. FIG. 10 is a diagram showing an example of the arrangement of the holes of the steam nozzle used in the wet tissue manufacturing method according to one embodiment of the present invention. FIG. 11 is a schematic diagram showing a modification of the wet tissue manufacturing apparatus used in the wet tissue manufacturing method according to an embodiment of the present invention.

  Hereinafter, the manufacturing method of the nonwoven fabric of one Embodiment of this invention is demonstrated with reference to figures. FIG. 1 is a perspective view of a package in which a wet tissue manufactured by a wet tissue manufacturing method according to an embodiment of the present invention is packaged, and FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a perspective view showing the wet tissue 4 in a folded state, and FIG. 4 is an enlarged perspective view of a part of the wet tissue.

  The package 1 includes a main body 2 having an opening 3, a wet tissue 4 accommodated in the main body 2, and a label member 5 that covers the opening 3 of the main body 2.

  The main body 2 has a bag shape, and seals the wet tissue 4 when the opening 3 is covered with the label member 5. Thereby, the main-body part 2 suppresses that the wet tissue 4 impregnated with the chemical | medical agent dries. The wet tissue 4 can be taken out through the opening 3 of the main body 2. Even after the label member 5 is peeled off from the main body 2, the label member 5 can be attached to the main body 2 again to cover the opening 3. Adhesive is applied.

  As shown in FIG. 2, the wet tissue 4 is laminated in a folded state in the main body 2. 2 and 3, the wet tissue 4 is folded so that the cross section is substantially Z-shaped, and the end 41 (upper end) of the wet tissue 4 on the opening side is also a cross section. Is folded so as to be substantially Z-shaped. The direction of the fold line of the wet tissue 4 corresponds to the machine direction (MD) in which the wet tissue 4 moves in the manufacturing method described later, and the width direction (CD) in which the folded direction is orthogonal to the machine direction (MD). It corresponds to. The wet tissue 4 can be easily taken out from the opening 5 by pinching the portion 41 that is folded in a substantially Z shape at the upper end of the wet tissue 4.

  As shown in FIG. 4, the wet tissue 4 includes a plurality of high bulk portions 42 extending in a predetermined direction and a groove portion 43 provided between the adjacent high bulk portions 42. The extending direction of the high bulk portion 42 corresponds to the machine direction (MD) in which the wet tissue 4 moves in the manufacturing method described later, and the direction in which the plurality of high bulk portions 42 are arranged is a width orthogonal to the machine direction (MD). It corresponds to the direction (CD).

  The high bulk portion 42 of the wet tissue 4 has a high density of fibers, and thus has a high basis weight. On the other hand, in the groove part 43 of the wet tissue 4, the density of fibers is low, and therefore the basis weight is low. Since the basis weight of the high-bulk portion 42 is high, when the object is wiped with the wet tissue 4, the high-bulk portion 42 can easily scrape the object. On the other hand, since the basis weight of the groove 43 is low, when the object is wiped with the wet tissue 4, the groove 43 can easily absorb dirt on the object. Therefore, the dirt of the object can be efficiently wiped off by the combination of the high-bulk portion 42 having a high basis weight and the groove portion 43 having a low basis weight.

  Next, with reference to FIG. 5, the manufacturing method of the wet tissue 4 in one Embodiment of this invention is demonstrated. The method of manufacturing the wet tissue 4 in one embodiment of the present invention includes a step of preparing a fiber sheet, a step of increasing the moisture content of the fiber sheet, a step of spraying high-pressure steam onto the fiber sheet, a step of folding the fiber sheet, and a chemical solution. A step of impregnating the fiber sheet, a step of cutting the fiber sheet, and a step of laminating the fiber sheet. FIG. 5 is a schematic view showing an example of a wet tissue manufacturing apparatus used in the method for manufacturing the wet tissue 4 in one embodiment of the present invention.

(Process for preparing fiber sheet)
A fiber sheet 51 is supplied from the rolls 11 and 12 to the conveyor 16. The fiber sheet 51 is a nonwoven fabric produced by a spunlace method, an airlaid method, or the like, and the basis weight of this nonwoven fabric is preferably 25 to 100 g / m ² . Further, since the fiber sheet 51 is deformed by high-pressure steam injection in a later step and the fibers of the fiber sheet 51 need to be loosened again, the nonwoven fabrics of the raw fabric rolls 11 and 12 are bonded by a water jet punch. It is preferable. Since the fiber sheet 51 is impregnated with a chemical solution, the nonwoven fabric used for the fiber sheet 51 includes hydrophilic fibers.

  It is preferable that polyphenylene sulfide (PPS) having high heat resistance is used for the conveyor 16.

  The volume of the fiber sheet 51 can be increased by a process of increasing the moisture content of the fiber sheet 51 described later and a process of spraying high-pressure steam onto the fiber sheet 51. Therefore, even when producing a bulky wet tissue, the bulk of the fiber sheets of the raw fabric rolls 11 and 12 may be low. Thereby, the original fabric rolls 11 and 12 with long winding length can be used, and the frequency | count of replacement | exchange of the original fabric rolls 11 and 12 can be decreased. Therefore, the production efficiency can be increased by the method for manufacturing the wet tissue 4 in one embodiment of the present invention.

(Process to increase the moisture content of the fiber sheet)
The fiber sheet 51 supplied to the conveyor 16 moves below the spray 13 that radiates water, and water is applied from the spray 13. As shown in FIG. 6, the nozzles 131 of the spray 13 are arranged side by side in the width direction (CD) of the fiber sheet 51. Thereby, the moisture content of the fiber sheet 51 increases. Here, the moisture content is the mass of water contained in the fiber sheet when the mass of the dried fiber sheet 51 is 100%.

  The moisture content of the fiber sheet 51 increased by the process of increasing the moisture content of the fiber sheet is not particularly limited as long as it is higher than the moisture content of the fiber sheet 51 in the raw fabric rolls 11 and 12, but is 10% or more and 45% or less. Preferably there is. When the moisture content of the fiber sheet 51 is smaller than 10%, the hydrogen bonding force between the fibers of the fiber sheet 51 becomes strong, and the energy required to loosen the fibers of the fiber sheet 51 by high-pressure steam described later becomes very high. . On the other hand, if the moisture content of the fiber sheet 51 is greater than 45%, the hydrogen bonding force between the fibers of the fiber sheet 51 becomes too weak, so that the strength of the fiber sheet 51 is too low or after high-pressure steam is injected. In order to increase the strength of the fiber sheet 51, a step of drying the fiber sheet 51 may be required after the step of injecting high-pressure steam described later onto the fiber sheet 51.

  In addition, if the moisture content of the fiber sheet 51 can be raised, the liquid radiated | emitted from the spray 13 is not limited to water. For example, an aqueous solution in which another compound is dissolved in water may be emitted from the spray 13.

  When the moisture content of the fiber sheet 51 is increased, the hydrogen bonding force between the fibers of the fiber sheet 51 is weakened, so that the entanglement between the fibers is weakened. For this reason, the fiber of the fiber sheet 51 can be easily loosened, and the processing of the fiber sheet 51 becomes easy.

  The hole diameter and hole pitch of the spray 13 are appropriately selected so that a predetermined amount of water is uniformly applied to the entire fiber sheet 51.

(Process of injecting high-pressure steam onto the fiber sheet)
Next, the fiber sheet 51 is moved between the steam nozzle 14 and the suction box 15 by the conveyor 16. At this time, high-pressure steam is sprayed onto the fiber sheet 51 from one steam nozzle 14 disposed above the conveyor 16. Note that high-pressure steam may be jetted to the fiber sheet 51 from two or more steam nozzles. The suction box 15 has a built-in suction device and sucks the high-pressure steam sprayed from the steam nozzle 14. Grooves are formed on the upper surface of the fiber sheet 51 (surface on the steam nozzle 14 side) by the high-pressure steam sprayed from the steam nozzle 14.

  The high-pressure steam sprayed from the steam nozzle 14 may be steam composed of 100% water, or steam containing other gas such as air. However, the high-pressure steam sprayed from the steam nozzle 14 is preferably steam composed of 100% water.

  An example of the steam nozzle 14 is shown in FIG. The steam nozzle 14 injects a plurality of high-pressure steam 142 arranged in the width direction (CD) of the fiber sheet 51 toward the fiber sheet 51. As a result, a plurality of grooves 512 extending in the machine direction (MD) are formed on the upper surface of the fiber sheet 51 along the width direction (CD) of the fiber sheet 51. A suction box 15 is provided on the opposite side of the steam nozzle 14 with respect to the conveyor 16.

  When high-pressure steam is sprayed on the fiber sheet 51, the fibers of the fiber sheet 51 are loosened. The loosened fibers are moved by the high-pressure steam on both sides in the width direction of the portion where the high-pressure steam is jetted. Thereby, the bulk of the fiber sheet 51 becomes high. The principle of increasing the bulk of the fiber sheet 51 will be described in detail with reference to FIG. 8, but this principle does not limit the present invention.

  As shown in FIG. 8, when the steam nozzle 14 ejects the high-pressure steam 142, the high-pressure steam 142 passes through the fiber sheet 51 and hits the conveyor 16. A part of the high-pressure steam 142 hitting the conveyor 16 is returned to the conveyor 16. Thereby, the fiber of the fiber sheet 51 is rolled up and loosened. In particular, since the hydrogen bond between fibers is weakened by applying water to the fiber sheet 51, the entanglement between the fibers is weak. For this reason, the fiber of the fiber sheet 51 is further easily rolled up, and thereby the fiber is further easily loosened.

  Further, the water in the fiber sheet 51 is rapidly evaporated by the high-pressure steam 142. By applying water to the fiber sheet 51, the moisture content of the fiber sheet 51 is increased, so that the expansion of water vapor due to the rapid evaporation of the water also increases. As a result, gaps between the fibers are increased, and the fibers are easily loosened.

  The fibers of the fiber sheet 51 are further divided by the high-pressure steam 142, and the separated fibers are moved and gathered on both sides in the width direction of the portion 514 where the high-pressure steam 142 hits the transport conveyor 16. A certain high bulk portion 513 is formed. In addition, since the fibers are concentrated in the high bulk portion 513, the basis weight of the high bulk portion 513 is increased. On the other hand, a groove portion 512 is formed in the fiber sheet 51 where the fibers are separated. In the groove part 512, since the fiber of the fiber sheet 51 is loosened, the basis weight of the groove part 512 becomes low.

  FIG. 9 is a schematic view showing a cross section in the width direction of the fiber sheet 51 after jetting high-pressure steam. The region 52 where the groove portion 512 exists is a region where the basis weight of the fiber sheet 51 is low, and the region 53 where the high bulk portion 513 exists is a region where the basis weight of the fiber sheet 51 is high. In the fiber sheet 51, the groove portions 512 and the high-bulk portions 513 are alternately present in the width direction, and the regions 52 having a low basis weight and the regions 53 having a high basis weight are alternately present in the width direction.

  When the fiber sheet 51 is produced using water-dispersible fibers having a fiber length of 20 mm or less, the fiber sheet 51 becomes a water-degradable wet tissue. The part with a low basis weight of the fiber sheet 51 is easily hydrolyzed. Therefore, since the fiber sheet 51 has regions 52 having a low basis weight and regions 53 having a high basis weight alternately in the width direction, when the fiber sheet 51 is used as a water-decomposable wet tissue, the wet tissue is rapidly hydrolyzed. be able to.

  Since the fiber sheet 51 is shaped by partially blowing the fibers with the high-pressure steam 51, the entanglement between the fibers is strong. For this reason, in order to maintain the bulky state of the fiber sheet 51, it is not necessary to mix a plastic fiber with the fiber sheet 51. In addition, since the high bulk portion 513 is formed on the fiber sheet 51 by collecting the fibers, the high bulk portion 513 is not easily crushed even when pressure is applied in the thickness direction or in a wet state. Therefore, in the process of impregnating with the chemical solution described later, even if the moisture content of the fiber sheet 51 increases, the high bulk portion 513 of the fiber sheet 51 is not crushed so much.

  A part of the high-pressure steam 142 hitting the conveyor 16 passes through the conveyor 16 and is sucked into the suction box 15. Thereby, the thermal energy of the high-pressure steam 142 is efficiently transmitted to the fiber sheet 51, and the fiber sheet 51 can be efficiently dried. Further, the suction of the suction box 15 can suppress the spread of water vapor generated after the high-pressure water vapor 14 is sprayed onto the fiber sheet 51. Thereby, it can suppress that dew condensation arises in the device around the steam nozzle 14.

  The temperature of the high-pressure steam is preferably 130 to 220 ° C. As a result, the drying of the fiber sheet 51 proceeds even when high-pressure steam is sprayed onto the fiber sheet 51, and the fiber sheet 51 dries at the same time as the bulk increases. When the fiber sheet 51 is dried, hydrogen bonding between the fibers of the fiber sheet 51 is strengthened, so that the strength of the fiber sheet 51 is increased and the increased bulk of the fiber sheet 51 is not easily crushed. In addition, since the strength of the fiber sheet 51 is increased, it is possible to prevent the fiber sheet 51 from being pierced or cut off by the injection of high-pressure steam.

  It is preferable that the steam pressure of the high-pressure steam sprayed from the steam nozzle 14 is 0.3 to 1.5 MPa. If the vapor pressure of the high-pressure steam is smaller than 0.3 MPa, the bulk of the fiber sheet 51 may not be so high due to the high-pressure steam. Further, when the vapor pressure of the high-pressure steam is larger than 1.5 MPa, the fiber sheet 51 may be perforated, the fiber sheet 51 may be torn or blown off.

  The suction box 15 has a built-in suction device that sucks the steam ejected from the steam nozzle 14. The suction force with which the suction box 15 sucks the fiber sheet 51 by this suction device is preferably −1 to −12 kPa. If the suction force of the suction box 15 is less than −1 kPa, there may be a problem that it is dangerous because the steam cannot be sucked up and is blown up. Further, if the suction force of the suction box 15 is larger than −12 kPa, there may be a problem that the fibers drop into the suction box.

  The distance between the tip of the steam nozzle 14 and the upper surface of the fiber sheet 51 is preferably 1.0 to 10 mm. If the distance between the tip of the steam nozzle 14 and the upper surface of the fiber sheet 51 is less than 1.0 mm, there may be a problem that the fiber sheet 51 is perforated, the fiber sheet 51 is torn or blown away. is there. Moreover, when the distance between the front-end | tip of the steam nozzle 14 and the upper surface of the fiber sheet 51 is larger than 10 mm, the force for forming a groove part in the surface of the fiber sheet 51 in a high pressure steam will disperse | distribute, and the fiber sheet 51 will be disperse | distributed. The efficiency of forming the groove on the surface of the film becomes worse.

  The hole diameter of the steam nozzle 14 is preferably 150 to 600 μm. If the hole diameter of the steam nozzle 14 is smaller than 150 μm, the energy of the high-pressure steam is insufficient, and there may be a problem that the fibers cannot be scraped sufficiently. Moreover, when the hole diameter of the steam nozzle 14 is larger than 600 μm, the energy of the high-pressure steam becomes too large, and there may be a problem that damage to the fiber sheet 51 due to the high-pressure steam becomes too large.

  It is preferable that the hole pitch (distance between the centers of adjacent holes) of the steam nozzle 14 is 1.0 to 10.0 mm. If the hole pitch of the steam nozzle 14 is smaller than 1.0 mm, the pressure resistance of the steam nozzle 14 may be reduced, and the steam nozzle 14 may be damaged. Moreover, when the hole pitch of the steam nozzle 14 is larger than 10.0 mm, the ratio of the part which received the process by the high pressure steam in a fiber sheet will become small, and the effect by the high pressure steam with respect to a fiber sheet may become small.

  The holes of the steam nozzle 14 may be arranged in a line in the width direction (CD) of the fiber sheet 51, or may be arranged in two or more lines. In FIG. 10, an example of arrangement | positioning of the hole of the steam nozzle 14 is shown. In the steam nozzle 14, the holes 143 arranged in the width direction (CD) of the fiber sheet 51 are arranged in two rows. The hole diameter is, for example, 300 μm, and the hole pitch, that is, the distance 144 between the centers of the adjacent holes 143 is, for example, 2.0 mm.

  By adjusting the hole diameter and hole pitch of the steam nozzle, the distance between the tip of the steam nozzle 14 and the upper surface of the fiber sheet 51, the moisture content of the fiber sheet 51, and the like, the height and width of the high bulk portion 513, the groove portion The depth and width of 512 can be adjusted. Therefore, the height and width of the high bulk portion 513, the depth and width of the groove portion 512, and the like can be easily controlled.

  The moisture content of the fiber sheet 51 after jetting high-pressure steam is preferably 0 to 20%, and more preferably 0 to 5%. If the moisture content of the fiber sheet 51 after jetting high-pressure steam is greater than 20%, the hydrogen bonding force between the fibers of the fiber sheet 51 becomes too weak, so that the fiber sheet 51 is subjected to processing in a later step. The strength of the fiber sheet 51 may be too low. Moreover, the drying process for raising the intensity | strength of the fiber sheet 51 after injecting high-pressure steam is unnecessary as the moisture content of the fiber sheet 51 after injecting high-pressure steam is 0 to 20%.

  By injecting high-pressure water vapor onto the fiber sheet 51 having an increased moisture content, the thickness of the fiber sheet 51 can be increased by 30% or more than the thickness of the fiber sheet 51 of the original fabric rolls 11 and 12.

  A cartridge heater 141 is provided on each of two surfaces of the steam nozzle 14 in the machine direction (MD). The cartridge heater 141 heats the steam nozzle 14 to a temperature higher than the temperature of the high-pressure steam jetted from the steam nozzle 14, preferably higher than 20 ° C. By heating the steam nozzle 14 with the cartridge heater 141 to a temperature higher than the temperature of the high-pressure steam ejected from the steam nozzle 14, it is possible to suppress the generation of drain in the steam nozzle 14. Thereby, it is possible to prevent water from dripping onto the fiber sheet 51 from the steam nozzle 14.

  For example, when the temperature of the high-pressure steam is 175 to 180 ° C. and the steam pressure of the high-pressure steam ejected from the steam nozzle 14 is 0.7 MPa, if the steam nozzle 14 is not heated by the cartridge heater 141, There is a case where a large amount of drainage is generated and the fiber sheet 51 is partially wetted. However, when the steam nozzle 14 is heated to 180 ° C. by the cartridge heater 141, the drain generated in the steam nozzle 14 is reduced. When the vapor nozzle 14 is heated to 190 ° C. by the cartridge heater 141, the drain generated in the vapor nozzle 14 is further reduced. When the vapor nozzle 14 is heated to 200 ° C. by the cartridge heater 141, the drain generated in the vapor nozzle 14 is further reduced, and the fiber sheet 51 is hardly wetted. When the steam nozzle 14 is heated to 210 ° C. by the cartridge heater 141, the drain is hardly generated in the steam nozzle 14, and the fiber sheet 51 is not affected by the drain.

  When water is dripped from the steam nozzle 14 onto the fiber sheet 51 due to the drain generated in the steam nozzle 14, there is a problem that a portion of the fiber sheet on which the water is dripped is broken in the process of folding the fiber sheet described later. There is a case.

(Process to fold fiber sheet)
As shown in FIG. 5, the fiber sheet 51 in which the high bulk portion and the groove portion are formed moves to the folding device 17. The folding device 17 includes, for example, a folding board 171 having a predetermined folding edge (not shown) and divided into two left and right, and a positioning stay 172 having a movable adjustment mechanism (not shown). In the folding device 17, the fiber sheet 51 is folded in the width direction as shown in FIG. 3.

(Process to impregnate the fiber sheet with the chemical solution)
The folded fiber sheet 51 passes through the impregnation device 18 and is impregnated with the chemical solution. The impregnation apparatus 18 includes an impregnation roll in which a plurality of pores are formed on the surface and capable of discharging a chemical solution from the plurality of pores, a chemical solution tank (not shown) that stores a chemical solution as a liquid, and the chemical solution tank to the impregnation roll A pump (not shown) for supplying a chemical solution. The fiber sheet 51 moves so as to contact the impregnation roll, and the fiber sheet 51 is impregnated with the chemical solution discharged from the impregnation roll. The fiber sheet 51 impregnated with the chemical solution passes through the transport roll 19.

  Next, the fiber sheet 51 supplied from one original fabric roll 11 and impregnated with the chemical solution and the fiber sheet 51 supplied from the other original fabric roll 12 and impregnated with the chemical solution are overlapped by the overlapping roll 20. Thereby, the lamination sheet 54 which consists of the fiber sheet 51 supplied from one original fabric roll 11 and the fiber sheet 51 supplied from the other original fabric roll 12 is produced.

  The laminated sheet 54 is conveyed to the cutting roll 23 while being sandwiched between the upper conveyor 21 and the lower conveyor 22. Thereby, when the lamination sheet 54 is conveyed, it can suppress that the lamination sheet 54 meanders.

(Process to cut fiber sheet)
With the cutting roll 23, the laminated sheet 54 is cut in the width direction at a predetermined interval in the machine direction (MD) to form a two-layer body 55 in which two wet tissues are stacked. The cutting roll 23 includes an anvil roll 231 having a smooth surface and a cutter roll 232 having a cutting blade on the surface.

(Process of laminating fiber sheets)
The two-layer body 55 is moved to the laminating device 25 by the transport conveyor 24. The laminating apparatus 25 includes a pressure 251, an upper transport conveyor 252 below the pressure 251, and a lower transport conveyor 253 disposed at a position facing the upper transport conveyor 252. The upper transport conveyor 252 has a suction mechanism (not shown), and this suction mechanism can adsorb the two-layer body 55 to the upper transport conveyor 252. The two-layer body 55 is adsorbed under the upper transfer conveyor 252. Further, the upper conveyor 252 is configured such that the pressure 251 can move downward through the upper conveyor 252. A plurality of two-layer bodies 55 are stacked on the lower conveyor 253 by pushers 251 that move up and down at predetermined time intervals. Then, a wet tissue laminate 56 in which a plurality of two-layer bodies 55 are laminated is produced.

  The wet tissue laminated body 56 is moved from the laminating apparatus 25 by the lower transfer conveyor 253. And it is packaged by a packaging process (not shown).

  A bulky fiber sheet can be used as a raw fabric roll, and a bulky wet tissue can be produced using the raw fabric roll. However, the high bulk portion of the fiber sheet is deformed when the fiber sheet with increased bulk is wound up in order to produce the raw fabric roll. For this reason, the high-bulk part of a wet tissue cannot be stably formed with the original fabric roll of the fiber sheet which raised the bulk. On the other hand, in one embodiment of the present invention, after increasing the bulk of the fiber sheet, the fiber sheet is subjected to the steps of folding the fiber sheet, impregnating the fiber sheet with a chemical solution, cutting the fiber sheet, and the fiber sheet. Proceed to the lamination process. Therefore, since the high bulk portion of the fiber sheet can proceed to the above process without being deformed, the high bulk portion of the wet tissue can be stably formed.

The wet tissue manufacturing method according to the above embodiment can be modified as follows.
(1) In the wet tissue manufacturing method according to the embodiment described above, the process proceeds in the order of folding the fiber sheet, impregnating the fiber sheet with the chemical solution, cutting the fiber sheet, and laminating the fiber sheet. However, the order in which the process proceeds is not limited to this. For example, the fiber sheet may be folded after the fiber sheet is cut. In addition, the chemical liquid may be impregnated after the fiber sheet is cut or after the cut fiber sheets are laminated before folding the fiber sheet.

(2) The step of folding the fiber sheet, the step of impregnating the fiber sheet with the chemical solution, the step of cutting the fiber sheet and the step of laminating the fiber sheet are respectively the step of folding the fiber sheet, the step of impregnating the fiber sheet with the chemical solution, If the step of cutting the fiber sheet and the step of laminating the fiber sheet, the step of folding the fiber sheet in the above embodiment, the step of impregnating the fiber sheet with the chemical solution, the step of cutting the fiber sheet and the fiber sheet are laminated. It is not limited to a process.

(3) In the wet tissue manufacturing method according to the embodiment described above, the vapor nozzle 14 is heated using the cartridge heater 141. However, if the vapor nozzle 14 can be heated, the apparatus for heating the vapor nozzle 14 includes the cartridge heater 141. It is not limited. For example, a pipe through which high-temperature steam flows may be disposed in the steam nozzle 14 to heat the steam nozzle 14.

(4) Although the moisture content of the fiber sheet 51 was raised by irradiating the fiber sheet 51 with water or an aqueous solution from the nozzle 13 according to the above embodiment, the moisture content of the fiber sheet 51 was raised by other methods. Also good. For example, by impregnating the fiber sheet 51 with water or an aqueous solution using an impregnation roll capable of discharging water or an aqueous solution from the plurality of pores formed on the surface, the moisture content of the fiber sheet 51 can be increased. It may be raised.

(5) Water or an aqueous solution may be applied only to the portion of the fiber sheet 51 that injects high-pressure steam, and the moisture content of only the portion of the fiber sheet 51 that injects high-pressure steam may be increased. Moreover, when making a part of the fiber sheet 51 bulky, you may make it raise the moisture content of only the part made the fiber sheet 51 bulky.

(6) In the wet tissue manufacturing apparatus 100 in one embodiment of the present invention described above, water or an aqueous solution is applied to the fiber sheet 51 and high-pressure steam is sprayed onto the fiber sheet 51 on the conveyor 16. As in the wet tissue manufacturing apparatus 100 </ b> A shown in FIG. 11, water or an aqueous solution may be applied to the fiber sheet 51 on the suction drum 16 </ b> A and high-pressure steam may be sprayed onto the fiber sheet 51. By using the suction drum 16A, it is possible to reduce the size of the wet tissue manufacturing apparatus as compared with the case where the transport conveyor 16 is used.

  It is also possible to combine one or a plurality of embodiments and modifications. It is possible to combine the modified examples in any way.

  The above description is merely an example, and the present invention is not limited to the above embodiment.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

  In Examples and Comparative Examples, fiber sheet moisture content before steam injection, fiber sheet moisture content after steam injection, fiber sheet basis weight, fiber sheet thickness, density, dry tensile strength, dry tensile elongation, wet tensile strength and wet tensile elongation Was measured as follows.

(Fiber sheet moisture content before steam injection)
In the wet tissue manufacturing apparatus 100 shown in FIG. 5, the fiber sheet 51 from which water was emitted from the spray 13 was sampled, and the mass (W1) of the sample piece of the sampled fiber sheet 51 was measured. Then, after leaving the sample piece to stand in a 105 degreeC thermostat for 1 hour, and making it dry further, the mass (D1) of the sample piece was measured. And the moisture content of the fiber sheet before vapor | steam injection was computed using the following formula.
Moisture content of fiber sheet before steam injection = (W1-D1) / W1 × 100 (%)
The average value of the fiber sheet moisture content before steam injection of 10 sample pieces was defined as the fiber sheet moisture content before steam injection of the example or comparative example corresponding to the sample piece.

(Fiber sheet moisture content after steam injection)
In the wet tissue manufacturing apparatus 100 shown in FIG. 5, the fiber sheet 51 into which high-pressure steam was jetted from the steam nozzle 14 was sampled, and the mass (W2) of the sample piece of the sampled fiber sheet 51 was measured. Then, after leaving the sample piece to stand in a 105 degreeC thermostat for 1 hour, and making it dry further, the mass (D2) of the sample piece was measured. And the moisture content after a steam blowing injection was computed using the following formula | equation.
Moisture content of fiber sheet after steam injection = (W2-D2) / W2 × 100 (%)
The average value of the fiber sheet moisture content after steam injection of ten sample pieces was used as the fiber sheet moisture content after steam injection of the example or comparative example corresponding to the sample piece.

(Fiber sheet basis weight)
In the wet tissue manufacturing apparatus 100 shown in FIG. 5, the fiber sheet 51 into which high-pressure steam was jetted from the steam nozzle 14 was sampled and cut into a size of 30 cm × 30 cm to produce a sample piece. Thereafter, the sample piece was left in a thermostat at 105 ° C. for 1 hour and further dried, and then the mass of the sample piece was measured. And the mass of the measured sample piece was divided by the area of the sample piece, and the fiber sheet weight per unit area was calculated.
The average value of the fiber sheet basis weight of 10 sample pieces was used as the fiber sheet basis weight of the example or comparative example corresponding to the sample piece.

(Fiber sheet thickness)
In the wet tissue manufacturing apparatus 100 shown in FIG. 5, the fiber sheet 51 into which high-pressure steam was jetted from the steam nozzle 14 was sampled, and the sampled fiber sheet 51 was cut into a size of 10 cm × 10 cm to produce a sample piece. Using a thickness gauge (model FS-60DS manufactured by Daiei Chemical Seiki Seisakusho Co., Ltd.) equipped with a 15 cm ² probe, the thickness of the sample piece was measured under measurement conditions of a measurement load of 3 g / cm ² . Three sample thicknesses were measured for one sample piece, and the average value of the three thicknesses was taken as the fiber sheet thickness of the example or comparative example corresponding to the fiber sheet.

(density)
The density of the fiber sheet was calculated from the basis weight of the fiber sheet and the thickness of the fiber sheet.

(Dry tensile strength)
In the wet tissue manufacturing apparatus 100 shown in FIG. 5, the fiber sheet 51 in which high-pressure steam is jetted from the steam nozzle 14 is sampled, and from the sampled fiber sheet 51, the longitudinal direction is 25 mm, which is the machine direction (MD) of the fiber sheet. A sample for measurement was prepared by cutting out a strip-shaped test piece having a width and a strip-shaped test piece having a width of 25 mm whose longitudinal direction is the width direction (CD) of the fiber sheet. Tensile tester equipped with a load cell with a maximum load capacity of 50 N (Shimadzu Corporation) for the tensile strength of each of three machine direction (MD) measurement samples and three width direction (CD) measurement samples (Manufactured by Autograph Model AGS-1kNG). The average value of the tensile strengths of the three measurement samples was taken as the dry tensile strength of the example or comparative example corresponding to the measurement sample.

(Dry tensile elongation)
In the wet tissue manufacturing apparatus 100 shown in FIG. 5, the fiber sheet 51 in which high-pressure steam is jetted from the steam nozzle 14 is sampled, and from the sampled fiber sheet 51, the longitudinal direction is 25 mm, which is the machine direction (MD) of the fiber sheet. A sample for measurement was prepared by cutting out a strip-shaped test piece having a width and a strip-shaped test piece having a width of 25 mm whose longitudinal direction is the width direction (CD) of the fiber sheet. The tensile elongation of each of the three machine direction (MD) measurement samples and the three width direction (CD) measurement samples was measured using a tensile testing machine equipped with a load cell having a maximum load capacity of 50 N (Shimadzu Corporation) ), Autograph Model AGS-1kNG), and measurement was performed under the conditions of a distance between grips of 100 mm and a tensile speed of 100 mm / min. Here, the tensile elongation is a value obtained by dividing the maximum elongation (mm) when the measurement sample is pulled by a tensile tester by the distance between grips (100 mm). The average value of the tensile elongation of the three measurement samples was taken as the dry tensile elongation of the example or comparative example corresponding to the measurement sample.

(Wet tensile strength)
In the wet tissue manufacturing apparatus 100 shown in FIG. 5, the fiber sheet 51 in which high-pressure steam is jetted from the steam nozzle 14 is sampled, and from the sampled fiber sheet 51, the longitudinal direction is 25 mm, which is the machine direction (MD) of the fiber sheet. A strip-shaped specimen having a width and a strip-shaped specimen having a width of 25 mm whose longitudinal direction is the width direction (CD) of the fiber sheet were cut, and 2.5 times the mass of the cut specimen was tested. A sample for measurement was prepared by impregnating a piece (moisture content, 250%). Tensile tester equipped with a load cell with a maximum load capacity of 50 N (Shimadzu Corporation) for the tensile strength of each of three machine direction (MD) measurement samples and three width direction (CD) measurement samples (Manufactured by Autograph Model AGS-1kNG), measurement was performed under the conditions of a distance between grips of 100 mm and a tensile speed of 100 mm / min. The average value of the tensile strengths of the three measurement samples was taken as the wet tensile strength of the example or comparative example corresponding to the measurement sample.

(Wet tensile elongation)
In the wet tissue manufacturing apparatus 100 shown in FIG. 5, the fiber sheet 51 in which high-pressure steam is jetted from the steam nozzle 14 is sampled, and from the sampled fiber sheet 51, the longitudinal direction is 25 mm, which is the machine direction (MD) of the fiber sheet. A strip-shaped specimen having a width and a strip-shaped specimen having a width of 25 mm whose longitudinal direction is the width direction (CD) of the fiber sheet were cut, and 2.5 times the mass of the cut specimen was tested. A sample for measurement was prepared by impregnating a piece (moisture content, 250%). The tensile elongation of each of the three machine direction (MD) measurement samples and the three width direction (CD) measurement samples was measured using a tensile testing machine equipped with a load cell having a maximum load capacity of 50 N (Shimadzu Corporation) ), Autograph Model AGS-1kNG), and measurement was performed under the conditions of a distance between grips of 100 mm and a tensile speed of 100 mm / min. The average value of the tensile elongation of the three measurement samples was taken as the wet tensile elongation of the example or comparative example corresponding to the measurement sample.

  Hereinafter, the production methods of Examples and Comparative Examples will be described.

Example 1
Example 1 was produced using the wet tissue manufacturing apparatus 100 in one embodiment of the present invention shown in FIG. The fiber sheet 51 was fed out from the raw fabric roll 11. The fiber sheet 51 is composed of 70% by weight of softwood bleached kraft pulp (NBKP) and 30% by weight of rayon (Corona, manufactured by Daiwabo Rayon Co., Ltd.) having a fineness of 1.1 dtex and a fiber length of 7 mm. . The fiber sheet 51 is a fiber sheet that has been subjected to a high-pressure water flow treatment with a paper machine when the fiber sheet 51 is manufactured. The high-pressure water flow energy of this high-pressure water treatment was 0.2846 kW / m ² . The unrolled fiber sheet 51 was moved under the spray 13 by the conveyor 16 (manufactured by Nippon Filcon Co., Ltd., using an 18 mesh polyphenylene sulfide (PPS) resin net).

  The moisture content of the fiber sheet 51 was increased by radiating water from the spray 13 (Spraycart III, manufactured by Spraying System Japan Co., Ltd.) to the fiber sheet 51. The moisture content of the fiber sheet 51 before increasing the moisture content of the fiber sheet 51 was 20%.

  Next, high-pressure steam was sprayed onto the fiber sheet 51 using the steam nozzle 14. The vapor pressure of the high-pressure steam at this time was 0.7 MPa, and the vapor temperature was 175 ° C. The temperature of the steam nozzle 14 heated by the cartridge heater 141 was 210 ° C. The distance between the tip of the steam nozzle 14 and the upper surface of the fiber sheet 51 was 2 mm. Furthermore, the arrangement | positioning of the hole of the steam nozzle 14 is an arrangement | positioning of the hole shown in FIG. 10, the hole diameter of the steam nozzle 14 was 300 micrometers, and the hole pitch was 2.0 mm. Further, the suction force with which the suction box 15 sucks the fiber sheet 51 was −5.0 kPa. The moisture content of the fiber sheet 51 after spraying the high-pressure steam onto the fiber sheet 51 was 5%. The fiber sheet 51 into which the high-pressure steam is jetted is Example 1. The line speed when manufacturing Example 1 was 70 m / min.

(Example 2)
Example 2 is the manufacturing method of Example 1 except that the amount of water radiated from the spray 13 to the fiber sheet 51 is adjusted so that the moisture content of the fiber sheet 51 before steam injection is 10%. Was produced by the same method. The moisture content of the fiber sheet 51 after jetting high-pressure steam onto the fiber sheet 51 was 3%.

(Example 3)
Example 3 is the manufacturing method of Example 1 except that the amount of water radiated from the spray 13 to the fiber sheet 51 is adjusted so that the moisture content of the fiber sheet 51 before steam injection is 45%. Was produced by the same method. The moisture content of the fiber sheet 51 after spraying the high-pressure steam onto the fiber sheet 51 was 17%.

Example 4
Example 4 was manufactured by the same method as that of Example 1 except that the distance between the tip of the steam nozzle 14 and the upper surface of the fiber sheet 51 was 10 mm. The moisture content of the fiber sheet 51 after spraying the high-pressure steam onto the fiber sheet 51 was 9%.

(Example 5)
Example 5 was manufactured by the same method as that of Example 1, except that the hole diameter of the steam nozzle 14 was 500 μm. The moisture content of the fiber sheet 51 after injecting high-pressure steam onto the fiber sheet 51 was 4%.

(Example 6)
Example 6 was manufactured by a method similar to the manufacturing method of Example 1 except that the vapor pressure of the high-pressure steam was set to 0.3 MPa. The moisture content of the fiber sheet 51 after spraying the high-pressure steam onto the fiber sheet 51 was 8%.

(Comparative Example 1)
Comparative Example 1 is the manufacturing method of Example 1 except that the amount of water radiated from the spray 13 to the fiber sheet 51 is adjusted so that the moisture content of the fiber sheet 51 before steam injection is 4%. Was produced by the same method. The moisture content of the fiber sheet 51 after injecting high-pressure steam onto the fiber sheet 51 was 4%.

(Comparative Example 2)
Comparative Example 2 is the manufacturing method of Example 1 except that the amount of water radiated from the spray 13 to the fiber sheet 51 is adjusted so that the moisture content of the fiber sheet 51 before steam injection is 50%. Was produced by the same method. The moisture content of the fiber sheet 51 after jetting high-pressure steam onto the fiber sheet 51 was 26%.

(Comparative Example 3)
Comparative Example 3 was manufactured by a method similar to the manufacturing method of Example 1 except that water was not applied to the fiber sheet 51 and high-pressure steam was not applied. The moisture content of the fiber sheet 51 was 20%.

  Detailed production conditions of the above Examples and Comparative Examples are shown in Tables 1-3.

  Table 2 shows the fiber sheet weight, fiber sheet thickness, density, dry tensile strength, dry tensile elongation, wet tensile strength, and wet tensile elongation of the above Examples and Comparative Examples.

(1) All fiber sheet thicknesses of Examples 1 to 6 were larger than those of Comparative Examples 1 and 3. From this, it was found that the bulk of the fiber sheet can be increased by increasing the moisture content of the fiber sheet before injecting the high-pressure steam onto the fiber sheet.
(2) Since the thickness of the fiber sheet of the original fabric roll was 0.35 mm, all the fiber sheet thicknesses of Examples 1 to 6 were 30% or more thicker than the thickness of the fiber sheet of the original fabric roll. I understood.
(3) All densities in Examples 1 to 6 were lower than those in Comparative Examples 1 and 3. From this, it was found that the fiber sheet can be softened by increasing the moisture content of the fiber sheet before injecting high-pressure steam onto the fiber sheet.
(4) It was found that when the moisture content of the fiber sheet was increased to 50%, the wet tensile strength was weakened although the bulk of the fiber sheet was increased.
(5) When the moisture content of the fiber sheet is increased to 50%, the moisture content of the fiber sheet 51 after jetting high-pressure steam onto the fiber sheet 51 is 26%, and the fiber sheet must be further dried. I understood it.

DESCRIPTION OF SYMBOLS 1 Packing body of wet tissue 2 Main body part 3 Opening part 4 Wet tissue 5 Label member 11,12 Original fabric roll 13 Spray 14 Steam nozzle 15 Suction box 16,24 Conveyor 17 Folding device 18 Impregnation device 19 Conveying roll 20 Overlap roll DESCRIPTION OF SYMBOLS 21 Upper conveyance conveyor 22 Lower conveyance conveyor 23 Cutting roll 25 Laminating apparatus 42,513 High bulk part 43,512 Groove part 51 Fiber sheet 100,100A Wet tissue manufacturing apparatus 141 Cartridge heater

Claims (8)

A wet tissue comprising: a step of preparing a fiber sheet; a step of folding the fiber sheet; a step of impregnating the fiber sheet with a chemical solution; a step of cutting the fiber sheet; and a step of laminating the fiber sheet. A manufacturing method comprising:
A wet tissue comprising a step of increasing the moisture content of the fiber sheet, and a step of spraying high-pressure steam onto the fiber sheet having an increased moisture content, between the step of preparing the fiber sheet and the subsequent step. Production method.   The method for producing a wet tissue according to claim 1, wherein the step of increasing the moisture content of the fiber sheet increases the moisture content of the fiber sheet to 10 to 45%.   The method of increasing the moisture content of the fiber sheet is a method of manufacturing a wet tissue according to claim 1 or 2, wherein the moisture content of the fiber sheet is increased by radiating or impregnating the fiber sheet with water or an aqueous solution.   The method for producing a wet tissue according to any one of claims 1 to 3, wherein a vapor pressure of the high-pressure steam is 0.3 to 1.5 MPa. Wherein the step of injecting the high-pressure steam to the fibrous sheet, the high-pressure steam that has passed through the fibrous sheet, a manufacturing method of wet tissue according to claim 4 for sucking by the suction force of -1 to-12 kPa. Method for producing wet tissue according to any one of claims 1 to 5 fiber sheet moisture content of the post-step is 0-20% for injecting high-pressure steam into the fiber sheet. The thickness of the fiber sheet after the step of injecting the high pressure steam to said fiber sheet, in any one of 30% or more thicker claims 1-6 than the thickness of the fiber sheet which is prepared by preparing a fibrous sheet The manufacturing method of the wet tissue of description. The step of injecting high-pressure steam into the fiber sheet is performed by injecting high-pressure steam from a steam nozzle,
The method of manufacturing a wet tissue according to any one of claims 1 to 7, wherein the steam nozzle is heated to a temperature that is higher by 20 ° C or more than a temperature of the high-pressure steam.

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