JP6104550B2 - Method for producing non-woven fabric - Google Patents

Description

  The present invention relates to a nonwoven fabric, and further relates to a method for producing the nonwoven fabric.

  Bulky paper is used as a wipe for cooking paper, paper towels, tissues, etc. In recent years, development of manufacturing technology related to bulky paper has been actively conducted for the purpose of further improving the quality of bulky paper.

  For example, in Patent Document 1, a fiber sheet having a moisture content of 50 to 85% by weight is transferred to an aperture pattern net that circulates along the suction portion, and the fiber sheet is held on the aperture pattern net. The fiber sheet is sucked, and water vapor having a calorie of 5 kcal / kg or more is sprayed on the fiber sheet simultaneously with the suction or before and after the suction to form a pattern corresponding to the aperture pattern net on the fiber sheet. There has been proposed a method for producing a bulky paper, which is characterized by obtaining a bulky paper patterned by drying in a drying step. According to the method for producing a bulky paper of the invention of Patent Document 1, by applying a heat quantity in the vicinity of the suction portion, pattern formability is improved, a bulky paper rich in bulkiness and absorbability is obtained, and the thickness is large. It is possible to obtain a bulky paper having high absorbency, excellent softness and moderate strength, and furthermore, since the aperture pattern net only circulates along the suction part, it is not necessary to manufacture a net so long. Have been described. In the invention of Patent Document 1, the pattern shape can be easily changed by a simple operation of simply replacing the aperture pattern net, and the aperture pattern net 31 is not guided into the drying process. Even if it is used continuously for a long time, it is difficult to deteriorate, and its service life is prolonged.Furthermore, by moving the patterning process and removing it from the traveling path of the fiber sheet, normal paper production can be facilitated. It is described that switching is easy.

Japanese Patent No. 3461122

  However, in the method for producing a bulky paper as described in, for example, Patent Document 1, a fiber sheet containing a predetermined moisture is pressed against an aperture pattern net as a support by an injection pressure of water vapor, and the aperture pattern net Since the fiber sheet has a pattern corresponding to the following, the following problems arise. In other words, the concave and convex mold made by the pattern net is easily crushed by processes such as winding and slitting, it is difficult to maintain bulk, and a pressing pattern is applied by the pressure of steam, so thermoplastic fibers etc. are used like embossing Otherwise, it is difficult to maintain the shape in the wet state. In addition, it is apparently bulky because the fiber sheet is pushed in, and the texture is bulky, but because the fibers are not moving, the fiber density is equivalent to the sheet before shaping Or partially densified. Furthermore, since the fiber sheet is not entangled, it is necessary to use a paper strength enhancer or the like in order to maintain the strength.

  The present invention solves the above-mentioned problems. That is, the present invention provides a method for producing a bulky nonwoven fabric using at least two high-pressure steam spray nozzles shifted in the width direction (CD direction) on each of at least two surfaces of the nonwoven fabric. For the purpose. Another object of the present invention is to provide a non-woven fabric having at least two surfaces and having a bulkiness in which the phase of the pattern of the concavo-convex portions formed on each of the at least two surfaces is different. And

Means for achieving the above object are the following items (1) to (11).
(1) supplying a papermaking raw material containing moisture onto a belt moving in one direction, and forming a paper layer having at least two surfaces on the belt;
Spraying high-pressure steam onto each of the at least two surfaces of the paper layer formed on the belt using a first high-pressure steam spray nozzle and a second high-pressure steam spray nozzle;
A method for producing a nonwoven fabric, comprising:
The step of injecting the high-pressure water vapor extends in the machine direction and is intermittently arranged in the width direction on one of the at least two surfaces of the paper layer using the first high-pressure water vapor injection nozzle. A first recess and a first protrusion are formed, and the second high-pressure steam spray nozzle is used to extend in the machine direction to the other of the at least two surfaces of the paper layer and intermittent in the width direction. A second concave portion and a second convex portion that are arranged side by side, the phase of the pattern of the first concave portion is different from the phase of the pattern of the second concave portion, and the phase of the pattern of the first convex portion is the first It is a process different from the phase of the pattern of the two convex portions.
A method of manufacturing a nonwoven fabric.
(2) supplying a papermaking raw material containing moisture onto a belt moving in one direction, and forming a paper layer having at least two surfaces on the belt;
Spraying high-pressure steam onto each of the at least two surfaces of the paper layer formed on the belt using a first high-pressure steam spray nozzle and a second high-pressure steam spray nozzle;
A method for producing a nonwoven fabric, comprising:
The step of injecting the high-pressure steam divides the distance of the full length portion of the first high-pressure steam injection nozzle into two equal parts, the position of the first virtual center line parallel to the machine direction, and the second high-pressure steam The first high-pressure steam injection nozzle is divided so that the distance of the full length portion of the injection nozzle in the width direction is divided into two equal parts, and the position of the second virtual center line parallel to the machine direction is different in the width direction. Disposing in one surface direction of the at least two surfaces of the paper layer and disposing the second high-pressure steam spray nozzle in the other surface direction of the at least two surfaces of the paper layer. Is,
A method of manufacturing a nonwoven fabric.
(3) In the step of injecting the high-pressure steam, the vapor pressure of the high-pressure steam is 0.2 MPa or more and 1.5 MPa or less, and the suction force of the suction drum or its belt is −1 kPa or more. A method for producing the nonwoven fabric according to item 1) or item (2).
(4) The moisture content of the paper layer after the step of jetting the high-pressure steam is 0% or more and 40% or less, and at least 5% of the moisture content of the paper layer before the step of jetting the high-pressure steam The method for producing the nonwoven fabric according to any one of items (1) to (3), which is low.
(5) Any one of items (1) to (4), wherein the vapor pressure on the other side of the paper layer is equal to or greater than the vapor pressure on the one side of the paper layer. A method for producing the nonwoven fabric according to item.
(6) After the step of forming the paper layer on the belt, a high-pressure water stream is jetted onto one of the at least two surfaces of the paper layer formed on the belt, and the machine direction is The nonwoven fabric according to any one of items (1) to (5), further comprising a step of forming a groove portion extending and intermittently arranged in the width direction on the one surface of the paper layer. How to manufacture.
(7) After the step of injecting the high-pressure water stream, the paper layer to which the high-pressure water stream has been jetted so that the paper layer to which the high-pressure water stream has been jetted has a moisture content of 10% to 45%. The method for producing a nonwoven fabric according to item (6), further comprising a step of drying by following the surface of the first rotating cylindrical dryer.
(8) a step of drying the paper layer on which the high-pressure water vapor has been jetted along the surface of the second rotating cylindrical dryer;
Winding up the dried paper layer;
Further including
The moisture content of the paper layer after winding of the dried paper layer is 5% or less,
A method for producing the nonwoven fabric according to any one of Items (1) to (7).
(9) The paper layer bulk density of the dried paper layer is 0.10 g / cm ³ or less by causing the paper layer on which the high-pressure steam is jetted to be along the surface of the second rotating cylindrical dryer. A method for producing the nonwoven fabric according to item (8).
(10) a longitudinal direction, a transverse direction intersecting the longitudinal direction, a thickness direction perpendicular to the longitudinal direction and the transverse direction, and one surface perpendicular to the thickness direction; The other surface facing the one surface in the thickness direction, the first recess formed on the one surface, extending in the vertical direction and intermittently arranged in the horizontal direction, and the first surface A first convex portion, and a second concave portion and a second convex portion formed on the other surface, extending in the longitudinal direction and intermittently arranged in the lateral direction;
A non-woven fabric having
The first concave portion and the second concave portion are displaced in the width direction from each other and positioned on the one surface and the other surface, respectively, and the first convex portion and the second convex portion are mutually in the width direction. Located on each of the one surface and the other surface,
Non-woven fabric.
(11) The nonwoven fabric according to (10), wherein the DRY cantilever evaluation value is 100 mm or less in the machine direction and the width direction.

  According to the present invention, there is provided a method for producing a bulky nonwoven fabric in which at least two high-pressure steam spray nozzles are shifted in the width direction (CD direction) on each of at least two surfaces of the nonwoven fabric. The Furthermore, according to the present invention, there is provided a nonwoven fabric having at least two surfaces, and having a bulkiness in which the phase of the pattern of the concavo-convex portions formed on each of the at least two surfaces is different. .

FIG. 1 is a view showing a nonwoven fabric production apparatus used in one embodiment of a method for producing a nonwoven fabric according to the present invention. FIG. 2 shows that high-pressure steam is jetted onto the front and back surfaces of a paper layer using the first high-pressure steam jet nozzle and the second high-pressure steam jet nozzle used in the method for producing a nonwoven fabric according to the present invention. It is an example figure. FIG. 3 shows a nozzle pattern of a high-pressure water flow nozzle used in the method for producing a nonwoven fabric according to the present invention, a nozzle pattern of a first high-pressure steam spray nozzle arranged on the back side of the paper layer, and a surface side of the paper layer. It is a figure of an example which shows the nozzle pattern of a 2nd high pressure steam injection nozzle. FIG. 4 is a schematic cross-sectional view showing the production process of one embodiment of the method for producing a nonwoven fabric according to the present invention. FIG. 5 is a schematic cross-sectional view showing one embodiment of the nonwoven fabric according to the present invention. FIG. 6 shows an example of a nozzle pattern of a high-pressure water flow nozzle used in the method for producing a nonwoven fabric according to the present invention, an example of a nozzle pattern of a first high-pressure steam spray nozzle on the back side of the paper layer, and the surface side of the paper layer. It is a figure which shows one example of the nozzle pattern nozzle pattern of the 2nd high pressure steam injection nozzle. FIG. 7 is a photomicrograph showing the front and back surfaces of the nonwoven fabric produced by carrying out Example 1, Comparative Example 1 and Comparative Example 2.

  A method for producing a nonwoven fabric according to the present invention comprises a step of supplying a papermaking raw material containing moisture onto a belt moving in one direction to form a paper layer having at least two surfaces on the belt, Injecting high-pressure steam onto each of at least two surfaces of the paper layer formed on the first and second high-pressure steam injection nozzles using the first high-pressure steam injection nozzle and the second high-pressure steam injection nozzle, 1 forming a first concave portion and a first convex portion extending in the machine direction and arranged intermittently in the width direction on one of the at least two surfaces of the paper layer using a high-pressure steam spray nozzle; A second concave portion and a second convex portion extending in the machine direction and intermittently arranged in the width direction are formed on the other of the at least two surfaces of the paper layer using a second high-pressure steam spray nozzle. The phase of the pattern of the first recess is Unlike turn phase, and wherein the phase of the pattern of the first protrusion is a phase different steps of the pattern of the second protrusion is a method for producing the nonwoven fabric.

Further, the method for producing a nonwoven fabric according to the present invention includes supplying a papermaking raw material containing moisture onto a belt moving in one direction, and forming a paper layer having at least two surfaces on the belt; Injecting high pressure steam onto each of the at least two surfaces of the paper layer formed on the belt using a first high pressure steam spray nozzle and a second high pressure steam spray nozzle;
And the step of injecting high-pressure water vapor divides the distance of the full length portion of the first high-pressure water vapor injection nozzle into two equal parts, the position of the first virtual center line parallel to the machine direction, and the second The first high-pressure steam spray nozzle is divided so that the distance of the full length part of the high-pressure steam spray nozzle in the width direction is halved and the position of the second virtual center line parallel to the machine direction is different in the width direction. Is disposed in the direction of one of the at least two surfaces of the paper layer, and the second high-pressure steam spray nozzle is disposed in the direction of the other surface of the at least two surfaces of the paper layer. A process for producing a non-woven fabric, characterized in that it is a process.

  At least two surfaces of the paper layer are in the direction 1 corresponding to the machine direction (MD direction), the direction 2 intersecting the direction 1 and corresponding to the width direction (CD direction), and the directions 1 and 2. Preferably, the direction 3 is perpendicular, one surface is perpendicular to the direction 3, and the other surface is opposed to the direction 3 with respect to the one surface. Of the two surfaces of the paper layer, the surface that contacts the surface of the belt is referred to as the back surface of the paper layer, and the surface that faces the back surface in the thickness direction of the paper layer is referred to as the surface of the paper layer. One of the two surfaces may be the back surface of the paper layer, and the other of the two surfaces may be the front surface, and one of the two surfaces may be the paper layer. The other surface of the two surfaces may be the back surface. The nozzle in the present invention refers to a device for ejecting liquid or gas having one or more holes. The nozzle in the present invention may have an arbitrary shape, but is preferably a box shape.

  The nonwoven fabric according to the present invention includes a longitudinal direction, a transverse direction intersecting the longitudinal direction, a thickness direction perpendicular to the longitudinal direction and the transverse direction, and one perpendicular to the thickness direction. The first surface, the other surface facing the one surface in the thickness direction, and the first surface extending in the longitudinal direction and intermittently arranged in the lateral direction. A concave portion and a first convex portion, and a second concave portion and a second convex portion formed on the other surface, extending in the longitudinal direction and intermittently arranged in the lateral direction; The second concave portion is displaced in the width direction from each other and is located on each of the one surface and the other surface, and the first convex portion and the second convex portion are displaced in the width direction from each other in the one surface and the other surface. It is a nonwoven fabric located on each of the surfaces. The vertical direction is the machine direction (MD direction) and is preferably the width direction (CD direction).

  When the surface treatment is performed in the same phase as the back-surface treatment part by the method for producing a nonwoven fabric according to the present invention, the paper layer is loosened from the front and back surfaces, resulting in a significant decrease in strength and a decrease in the surface area due to the back-surface treatment. Therefore, the amount of fibers that can be surface-treated is small, and it can be formed only to such an extent that the uneven-shaped forming cannot be understood. Therefore, by shifting the phase, a significant decrease in strength can be prevented, and the surface side is also sufficient. It is possible to develop a non-uniform embossed mold, and it is possible to produce a double-sided embossed nonwoven fabric, and the high pressure steam treatment is applied to the entire paper layer by shifting the phase from the front and back. Therefore, the moisture content of the paper layer can be effectively reduced, the drying efficiency can be increased, and the flexibility of the nonwoven fabric can be increased. In addition, according to the method for producing a nonwoven fabric according to the present invention, it is possible to produce a wipe having good wiping properties on both the front and back of the nonwoven fabric when used as a wipe by forming a large uneven mold on both sides of the nonwoven fabric by shifting the phase. Also, when used as DRY wipes and WET wipes, a bulky and flexible nonwoven fabric can be obtained with little difference between the front and back, so in the case of pop-up WET wipes, surface friction between the nonwoven fabrics is important for smooth pop-up Although it becomes an element, the contact area between the nonwoven fabrics is reduced by performing both-side molding, and it is possible to pop up smoothly. Here, the pop-up is a method that when one sheet is taken out like a BOX tissue, the next sheet is pulled out to a position where it can be easily removed. Decrease.

  Further, according to the method for producing a nonwoven fabric according to the present invention, after the paper layer is formed, the fibers are entangled by high-pressure water flow treatment to give the paper layer strength, and then the transport process to the transport conveyor, press for dewatering Passing through the step of reducing the paper layer thickness by applying pressure to the paper layer, such as the step of transporting the paper layer to the rotating cylindrical dryer, and after passing through the at least one rotating cylindrical dryer, the first high-pressure steam spray nozzle By using high pressure water vapor on the back side of the high pressure water flow treatment and applying heat and pressure at the same time, the fibers are scraped while forming the nozzle marks on the nonwoven fabric, forming irregularities and making the fibers loose at the same time The flexibility of the paper layer is increased and the moisture content of the paper layer is reduced, and then the second high-pressure steam spray nozzle is used to treat the high-pressure water treatment surface side (to the first high-pressure steam spray nozzle). That in spraying the backside), and, spraying high-pressure steam so as not to overlap the blowing portion by the first high-pressure steam injection nozzle, with a high-pressure steam spraying nozzle marks on both sides of the paper layer, to form a concave-convex shaping. Since the fiber entanglement is stronger on the high-pressure water jet side than on the back side, the amount of energy required to scrape and form the fibers is higher than that on the back side, and the first high-pressure steam jet nozzle and the second high-pressure steam jet are required. By making the nozzle as close as possible, it is possible to make it difficult for phase shift due to the meandering of the nonwoven fabric. The second high-pressure steam spray nozzle can be moved horizontally with respect to the machine drive direction, and can be adjusted when a phase shift occurs. Moreover, in order to efficiently perform unevenness formation with high-pressure saturated steam, it is important that the paper layer contains moisture so that the fibers can move easily. If the moisture content is too low, a strong hydrogen bonding force is generated in the paper layer, and a large amount of high-pressure steam energy is required to form irregularities, resulting in a significant reduction in efficiency.

  However, if the moisture content of the paper layer during high-pressure steam treatment is high, high-pressure steam energy is required greatly when the high-pressure steam treatment is also used for final drying, and the efficiency is remarkably deteriorated. At this time, in order to increase the drying efficiency, high-pressure steam at a temperature higher than the temperature of the first rotating cylindrical dryer is sprayed to reduce the moisture content of the paper layer after the high-pressure steam treatment by 5% or more, and the paper layer temperature is No. .1 By making the temperature of the paper layer at the dryer outlet equal to or higher than that, the final drying efficiency in the first rotating cylindrical dryer can be effectively increased. Further, since the high-pressure steam treatment is performed to a certain degree of dryness (raw dryness), it is possible to form an uneven mold while proceeding with drying, and to create a molded state in which the bulk is not easily crushed during winding. In addition, the method of producing the nonwoven fabric of the present invention is usually caused by high-pressure steam molding, and the paper layer strength is lowered and depending on the molding conditions, the strength becomes too low and breakage or the like is likely to occur during production. Then, drying is promoted at the same time as shaping (hydrogen bonding force is generated when dried), so that an extreme decrease in strength of the nonwoven fabric due to the shaping treatment does not occur, and troubles such as cutting that deteriorates productivity can be prevented.

  Hereinafter, the nonwoven fabric and the method for producing the nonwoven fabric according to the present invention will be described in more detail with reference to the drawings. In addition, the nonwoven fabric of this invention and the method of manufacturing a nonwoven fabric are not limited to embodiment of this invention represented with a figure in the range which does not deviate from the objective and main point of this invention.

  FIG. 1 is a diagram for explaining a nonwoven fabric manufacturing apparatus 1 used in an embodiment of a method for manufacturing a nonwoven fabric according to the present invention. A papermaking raw material containing moisture such as a fiber suspension is supplied to the raw material supply head 11. The papermaking raw material supplied to the raw material supply head 11 is supplied from the raw material supply head 11 onto a paper layer forming belt of a paper layer forming conveyor 16 (also referred to as a paper layer forming belt) and is deposited on the paper layer forming belt. The paper layer forming belt is preferably a support having air permeability through which steam can pass. For example, a wire mesh, a blanket, etc. can be used as a paper layer forming belt.

  As a fiber used for the papermaking raw material supplied to the raw material supply head 11, for example, a short fiber having a fiber length of 20 mm or less is preferable. Such short fibers include, for example, wood pulp such as soft and hardwood chemical pulp, semi-chemical pulp and mechanical pulp, mercerized pulp and cross-linked pulp obtained by chemically treating these wood pulp, and non-wood fibers such as hemp and cotton. In addition, cellulosic fibers such as regenerated fibers such as rayon fibers, and synthetic fibers such as polyethylene fibers, polypropylene fibers, polyester fibers, and polyamide fibers. The fibers used for the papermaking raw material are particularly preferably cellulosic fibers such as wood pulp, non-wood pulp, and rayon fiber.

  The papermaking raw material deposited on the paper layer forming belt is appropriately dehydrated by the suction box 15 to form the paper layer 23. The paper layer 23 includes two high-pressure water flow nozzles 12 disposed on the paper layer formation belt and two suction boxes 15 disposed at positions facing the high-pressure water flow nozzle 12 with the paper layer formation belt interposed therebetween. Pass between. The high-pressure water flow nozzle 12 injects a high-pressure water flow onto the paper sheet 23. The suction box 15 sucks and collects the water sprayed from the high-pressure water flow nozzle 12. A high pressure water flow is jetted from the high pressure water flow nozzle 12 onto the paper layer 23, and a groove is formed on the surface of the paper layer 23.

  The high-pressure water nozzle 12 injects a plurality of high-pressure water streams arranged in the width direction (CD) of the paper layer 23 toward the paper layer 23. As a result, on the surface of the paper layer 23, a plurality of groove portions that are intermittently arranged in the width direction (CD) of the paper layer 23 and extend in the machine direction (MD) are formed.

  When the paper layer 23 receives a high-pressure water flow, a groove is formed in the paper layer 23 and the fibers of the paper layer 23 are entangled with each other, and the strength of the paper layer 23 is increased.

  When the high pressure water flow nozzle 12 ejects the high pressure water flow onto the paper layer 23, the high pressure water flow passes through the paper layer 23 and the paper layer forming belt. Thereby, the fibers of the paper layer 23 are drawn toward a predetermined portion where the high-pressure water flow passes through the paper layer forming belt 41. As a result, the fibers of the paper layer 23 gather toward a predetermined portion where the high-pressure water stream passes through the paper layer forming belt, and the fibers are entangled with each other.

  When the fibers of the paper layer 23 are entangled, the strength of the paper layer 23 is increased. As a result, even if high-pressure steam is jetted onto the paper layer 23 in a later step, the paper layer 23 is less likely to be perforated, the paper layer 23 torn, or blown away. Further, the wet strength of the paper layer 23 can be increased without adding a paper strength enhancer to the papermaking raw material.

  Grooves are formed on the surface of the paper layer 23 by the high-pressure water flow. A pattern (not shown) corresponding to the pattern of the paper layer forming belt is formed on the surface opposite to the surface on which the high-pressure water flow is jetted.

  Thereafter, as shown in FIG. 1, the paper layer 23 is transported to the paper layer transport conveyor 18 by the suction pickup 17. Further, the paper layer 23 is transported to the paper layer transporting conveyor 19 and then transported to the first rotating cylindrical dryer 20.

  By placing the paper layer 23 along the surface of the first rotary cylindrical dryer 20, the paper layer 23 to which the high-pressure water stream has been jetted is dried. As the first rotating cylindrical dryer, for example, a Yankee dryer may be used. The first rotating cylindrical dryer 20 may be a rotating cylindrical dryer, and the surface of the first rotating cylindrical dryer 20 may be heated to about 160 ° C. by steam or the like.

  The first rotating cylindrical dryer 20 dries the paper layer 23 so that the moisture content is preferably 10 to 45%, more preferably 20 to 40%. Here, the moisture content is the amount of water contained in the paper layer when the dry mass of the paper layer 23 is 100%.

  When the moisture content of the paper layer 23 is smaller than 10%, the hydrogen bonding force between the fibers of the paper layer 23 becomes strong, and the energy required to loosen the fibers of the paper layer 23 by high-pressure steam described later becomes very high. There is a case. If the moisture content of the paper layer 23 is smaller than 10%, the adhesion of the paper layer 23 to the surface of the first rotating cylindrical dryer 20 may be weakened.

  On the other hand, when the moisture content of the paper layer 23 is greater than 45%, the energy required for drying the paper layer 23 to a predetermined moisture content or less by high-pressure steam described later may become very high. Moreover, when the moisture content of the paper layer 23 is greater than 45%, the hydrogen bonding force between fibers in the paper layer may be weakened.

  Next, as shown in FIG. 1, the paper layer 23 that has passed through the first rotating cylindrical dryer 20 moves onto the mesh-shaped outer peripheral surfaces of the cylindrical suction drum 13-1 and the suction drum 13-2. After that, as shown in FIG. 2, high-pressure steam is jetted onto the paper layer 23 from the first high-pressure steam jet nozzle 14-1 disposed above the outer peripheral surface of the suction drum 13-1, and then the suction drum 13. -2 is jetted onto the paper layer 23 from the second high-pressure steam jet nozzle 14-2 disposed below the outer peripheral surface. As shown in FIG. 1, the surface on which the high-pressure water flow is jetted is the surface of the paper layer 23, so the surface on which the first high-pressure steam jet nozzle 14-1 jets high-pressure steam is the back surface of the paper layer 23, and the second The surface on which the high-pressure steam spray nozzle 14-2 sprays high-pressure steam is the surface of the paper layer 23. The first high-pressure steam spray nozzle 14-1 and the second high-pressure steam spray nozzle 14-2 divide the distance of the full length portion of the first high-pressure steam spray nozzle 14-1 into two equal parts and are parallel to the machine direction. The position of the first virtual center line and the position of the second virtual center line that is parallel to the machine direction are divided in half by dividing the distance of the full length portion of the second high-pressure steam injection nozzle 14-2 in the width direction. They are arranged differently. The first high-pressure steam spray nozzle 14-1 is disposed on the back surface of the paper layer 23, and the second high-pressure steam spray nozzle 14-2 is disposed on the surface of the paper layer 23. The suction drum 13-1 and the suction drum 13-2 have a built-in suction device, and the high-pressure steam sprayed from the first high-pressure steam spray nozzle 14-1 and the second high-pressure steam spray nozzle 14-2 is sucked by the suction device. Is done. As shown in FIG. 2, the concave portion 32 and the convex portion 33 are wider on the back surface of the paper layer 23 than the groove portion formed by the high-pressure water flow due to the high-pressure steam jetted from the first high-pressure steam jet nozzle 14-1. Next, the high-pressure steam jetted from the second high-pressure steam jet nozzle 14-2 causes the concave portion 34 and the convex portion 35 to have a larger width than the groove portion formed by the high-pressure water flow on the surface of the paper layer 23. Is formed. The concave portion 32 and the convex portion 33, and the concave portion 34 and the convex portion 35 can extend in the machine direction (MD direction) and can be intermittently arranged in the width direction (CD direction). Further, the phase of the pattern of the concave portion 32 is different from the phase of the pattern of the concave portion 34, and the phase of the pattern of the convex portion 33 is different from the phase of the pattern of the convex portion 35.

  In addition, if a high-pressure steam spray nozzle trace is attached to both the front and back sides of the paper layer to form an uneven mold, the first high-pressure steam spray nozzle (back side) of the nonwoven fabric manufacturing apparatus 1 shown in FIG. And the second high-pressure steam spray nozzle (front side) is not limited to the arrangement, for example, after the high-pressure steam from the first high-pressure steam spray nozzle is sprayed on the back surface of the paper layer, the paper layer itself is 180 degrees in the width direction. Inverted, high-pressure steam from the second high-pressure steam spray nozzle may be sprayed onto the surface of the paper layer. In that case, the first high-pressure steam spray nozzle and the second high-pressure steam spray nozzle are both disposed above or below the paper layer transport belt (paper layer transport path) in the step of spraying high-pressure steam in the nonwoven fabric manufacturing apparatus.

  The high-pressure steam sprayed from the first high-pressure steam spray nozzle 14-1 and the second high-pressure steam spray nozzle 14-2 may be steam composed of 100% water, or steam containing other gas such as air. . However, the high-pressure steam ejected from the first high-pressure steam spray nozzle 14-1 and the second high-pressure steam spray nozzle 14-2 is preferably steam composed of 100% water.

  The temperature of the high-pressure steam is preferably 105 to 220 ° C. As a result, the drying of the paper layer 23 proceeds even when high-pressure steam is sprayed onto the paper layer 23, and the paper layer 23 dries at the same time as the bulk increases. When the paper layer 23 is dried, the hydrogen bonds between the fibers of the paper layer 23 are strengthened, so that the strength of the paper layer 23 is increased and the increased bulk of the paper layer 23 is not easily crushed. In addition, since the strength of the paper layer 23 is increased, it is possible to prevent the paper layer 23 from being perforated or the paper layer 23 from being cut by the injection of high-pressure steam.

  FIG. 3 shows a nozzle pattern 41 of a high-pressure water flow nozzle, a nozzle pattern 42 of a first high-pressure steam spray nozzle disposed on the back side of the paper layer 23, and a second high-pressure steam spray nozzle disposed on the front side of the paper layer 23. It is a figure of an example which shows the nozzle pattern 43 of this. The nozzle pattern of the high pressure water flow nozzle, the nozzle pattern of the first high pressure steam spray nozzle and the nozzle pattern of the second high pressure steam spray nozzle are determined by the hole diameter and nozzle pitch, respectively. The nozzle pattern 41 of the high-pressure water nozzle is arranged in a row with holes in a row in the width direction (CD) of the paper layer. The hole diameter of the nozzle pattern 41 of the high-pressure water flow nozzle may be 90 to 150 μm. When the hole diameter of the nozzle pattern 41 of the high-pressure water flow nozzle is smaller than 90 μm, the high-pressure water flow nozzle may be easily clogged, and when the hole diameter is larger than 150 μm, the processing efficiency may be deteriorated.

  The nozzle pitch (the distance between the centers of two holes adjacent in the width direction (CD)) of the nozzle pattern 41 of the high-pressure water flow nozzle may be 0.5 to 1.0 mm. When the nozzle pitch of the nozzle pattern 41 of the high-pressure water flow nozzle is smaller than 0.5 mm, the pressure resistance of the nozzle may be reduced and may break, and when the nozzle pitch is larger than 1.0 mm, the fiber entanglement becomes insufficient. There is a case.

  As shown in FIG. 3, the nozzle pattern 42 of the first high-pressure steam spray nozzle arranged on the back side of the paper layer 23 has holes arranged in the width direction (CD direction) of the paper layer in the machine direction (MD direction). The nozzle pattern 43 of the second high-pressure steam spray nozzle arranged in three rows on the surface side of the paper layer 23 is machine direction with the holes forming a row in the width direction (CD direction) of the paper layer. They are arranged in three rows in the (MD direction). Therefore, as shown in FIG. 2, the plurality of high-pressure steams 31 arranged in the width direction (CD direction) are arranged in the machine direction (MD) by the first high-pressure steam spray nozzles 14-1 arranged on the back side of the paper layer 23. Direction) in three rows. The plurality of high-pressure steams 31 arranged in the width direction (CD direction) are arranged in three rows in the machine direction (MD direction) by the second high-pressure steam injection nozzle 14-2 arranged on the surface side of the paper layer 23. . In addition, three hole rows that are arranged in the width direction (CD direction) of the nozzle pattern 42 of the first high-pressure steam injection nozzle and the nozzle pattern 43 of the second high-pressure steam injection nozzle are arranged in the machine direction (MD direction). The number is not limited to three, and may be one, two, or four or more. Further, by arranging the first high-pressure steam spray nozzles 14-1 or the second high-pressure steam spray nozzles 14-2 in the machine direction (MD direction), a plurality of hole rows arranged in the width direction (CD direction) are formed. You may arrange so that a line may be made | formed in a machine direction (MD direction). In addition, by arranging the holes so that the plurality of hole rows arranged in the width direction (CD direction) form a plurality of rows in the machine direction (MD direction), the uneven portion can be reliably formed in the paper layer. Thus, the bulk of the paper layer may be reliably increased.

  As shown in FIG. 3, it is preferable that the hole diameter of the nozzle pattern 42 of the 1st high pressure steam injection nozzle arrange | positioned at a back surface side is 200 micrometers-600 micrometers. If the hole diameter of the nozzle pattern 42 of the first high-pressure steam spray nozzle is smaller than 200 μm, it may be difficult to form unevenness due to insufficient processing energy. If the hole diameter is larger than 600 μm, the amount of energy becomes too large. There are cases where the layers are torn.

  As shown in FIG. 3, the nozzle pitch (the distance between the centers of two holes adjacent in the width direction (CD direction) of the nozzle pattern 42 of the first high-pressure steam spray nozzle arranged on the back surface is defined. Is preferably 3 mm to 20 mm. As shown in FIG. 3, the nozzle pitch may be a fixed distance, and unlike the case shown in FIG. 3, the nozzle pitch may not be a fixed distance. If the nozzle pitch is smaller than 3 mm, it may be close to the entire surface processing, and there may be no phase difference between the front and back sides. If the nozzle pitch is larger than 20 mm, the distance between the concave and convex molds becomes too wide and bulky. There are cases where it tends to collapse.

  As shown in FIG. 3, it is preferable that the hole diameter of the nozzle pattern 43 of the 2nd high pressure steam injection nozzle arrange | positioned at the surface side is 200 micrometers-600 micrometers. If the hole diameter of the nozzle pattern 43 of the second high-pressure steam spray nozzle is smaller than 200 μm, it may be difficult to form unevenness due to insufficient processing energy. If the hole diameter is larger than 600 μm, the amount of energy becomes too large. There are cases where the layers are torn.

  As shown in FIG. 3, the nozzle pitch (distance between the centers of two holes adjacent to each other in the width direction (CD direction)) of the nozzle pattern 43 of the second high-pressure steam spray nozzle arranged on the front side is 3 mm to 20 mm. It is preferable that As shown in FIG. 3, the nozzle pitch may be a fixed distance, and unlike the case shown in FIG. 3, the nozzle pitch may not be a fixed distance. If the nozzle pitch is smaller than 3 mm, it may be close to the entire surface processing, and there may be no phase difference between the front and back sides. If the nozzle pitch is larger than 20 mm, the distance between the concave and convex molds becomes too wide and bulky. There are cases where it tends to collapse.

  As shown in FIG. 3, the nozzle pattern 42 of the first high-pressure steam spray nozzle is arranged so that the position of the first virtual center line and the position of the second virtual center line described above are different in the width direction (CD direction). A nozzle pattern 43 of the second high-pressure steam spray nozzle is disposed. That is, as shown in FIG. 3, the nozzle pattern 43 of the second high-pressure steam spray nozzle is directed in the width direction (CD direction) toward the machine direction (MD direction) with respect to the nozzle pattern 42 of the first high-pressure steam spray nozzle. ) To be shifted to the left side. Although not shown, if the nozzle pattern of the first high-pressure steam spray nozzle and the nozzle pattern of the second high-pressure steam spray nozzle are the same, that is, the hole diameter of the first high-pressure steam spray nozzle and the hole diameter of the second high-pressure steam spray nozzle Are the same size, and the nozzle pitch of the nozzle pattern of the first high-pressure steam spray nozzle is the same as the nozzle pitch of the nozzle pattern of the second high-pressure steam spray nozzle, the first high-pressure steam spray nozzle Even if the nozzle pattern of the second high-pressure steam spray nozzle is shifted to the left or right side in the width direction toward the machine direction with respect to the nozzle pattern of When the holes of the nozzle pattern of the high-pressure steam spray nozzle are aligned in a straight line toward the machine direction, the first high-pressure steam spray The phase of the pattern of the first recess formed by the slip and the phase of the pattern of the second recess formed by the second high-pressure steam spray nozzle are the same, and the first pattern formed by the second high-pressure steam spray nozzle The phase of the pattern of one convex part and the phase of the pattern of the second convex part formed by the second high-pressure steam spray nozzle may be the same.

  The vapor pressure of the high-pressure steam injected from the first high-pressure steam injection nozzle 14-1 and the second high-pressure steam injection nozzle 14-2 is preferably 0.2 to 1.5 MPa. If the vapor pressure of the high-pressure steam is smaller than 0.2 MPa, the bulk of the paper layer 23 may not be so high by the high-pressure steam 31. In addition, when the vapor pressure of the high-pressure steam is higher than 1.5 MPa, the paper layer 23 may be perforated, the paper layer 23 may be torn, or blown off.

  When the high-pressure steam 31 is jetted onto the paper layer 23, first, the fibers of the entire paper layer 23 are loosened by the jetting of the first high-pressure steam jet nozzle 14-1 disposed on the back side, and the back side of the paper layer 23 is The bulk becomes high, and the fibers of the entire paper layer 23 are loosened by the jetting by the second high-pressure steam jet nozzle 14-2 arranged on the front side, and the bulk on the front side of the paper layer 23 becomes high. The back side bulk and the front side bulk deviate in the width direction (CD direction). Thereby, the softness | flexibility of the paper layer 23 increases and the tactile sense of the paper layer 23 is improved.

  When the first high-pressure steam spray nozzle 14-1 disposed on the back side sprays the high-pressure steam 31, the high-pressure steam 31 hits the suction drum 13-1. When the second high-pressure steam spray nozzle 14-2 disposed on the front side sprays the high-pressure steam 31, the high-pressure steam 31 hits the suction drum 13-2. The high-pressure steam 31 is mostly returned to the suction drums 13-1 and 13-2. As a result, the fibers of the paper layer 23 are rolled up and loosened. Then, the fibers of the loosened paper layer 23 are scraped by the high-pressure steam 31. As a result, the concave portion 32 and the convex portion 33 are formed in the paper layer 23 by the ejection of the first high-pressure steam spray nozzle 14-1 disposed on the back surface side, and the second high-pressure steam spray nozzle 14 disposed on the front surface side. The concave portion 34 and the convex portion 35 are formed by the injection of -2. The separated fibers gather as the high-pressure steam 31 moves to the width direction side of a predetermined portion corresponding to the paper layer 23, and the bulk of the paper layer 23 increases. Further, the moisture contained in the paper layer 23 is evaporated by the heat of the high-pressure steam 31 and is removed from the paper layer 23. Thereby, the drying of the paper layer 23 proceeds.

  In the method for producing a nonwoven fabric according to the present invention, in order to increase the bulk of the paper layer, the concavo-convex portion is formed on the paper layer with high-pressure steam. Therefore, in order to increase the amount of fibers scraped by the high-pressure steam, the width of the recess formed by the high-pressure steam is larger than the width of the recess formed by the high-pressure water flow.

  The suction drum or suction belt built in the suction drums 13-1 and 13-2 sucks the high-pressure steam jetted from the first high-pressure steam jet nozzle 14-1 and the second high-pressure steam jet nozzle 14-2. 13-1 and 13-2, or the suction force with which the belt sucks the paper layer 23 is preferably −1 to −12 kPa. If the suction force of the suction drums 13-1 and 13-2 or the belt is less than -1 kPa, the steam may not be sucked and blowing up may occur. Further, if the suction force of the suction drums 13-1 and 13-2 or the belt is larger than -12 kPa, there are cases where the fibers fall into the suction.

  The distance between the tip of the first high-pressure steam spray nozzle 14-1 and the top surface of the paper layer 23, and the distance between the tip of the second high-pressure steam spray nozzle 14-2 and the top surface of the paper layer 23 are: Preferably it is 1.0-10 mm. The distance between the tip of the first high-pressure steam spray nozzle 14-1 and the top surface of the paper layer 23 and the distance between the tip of the second high-pressure steam spray nozzle 14-2 and the top surface of the paper layer 23 are 1. If it is smaller than 0.0 mm, a hole may be formed in the paper layer 23, or the paper layer 23 may be torn or blown off. Also, the distance between the tip of the first high-pressure steam spray nozzle 14-1 and the top surface of the paper layer 23, and the distance between the tip of the second high-pressure steam spray nozzle 14-2 and the top surface of the paper layer 23. If it is larger than 10 mm, the force for forming uneven portions on the surface of the paper layer 23 in high-pressure steam is dispersed, and the efficiency of forming the uneven portions on the surface of the paper layer 23 may deteriorate.

  The moisture content of the paper layer 23 after the step of spraying high-pressure steam is preferably 0% or more and 40% or less, more preferably 0% or more and 35% or less, and further preferably 0% or more and 30% or less. . If the moisture content of the paper layer 23 after jetting high-pressure steam is greater than 40%, it may be difficult to reduce the moisture content of the paper layer 23 to 5% or less by drying with a second rotating cylindrical dryer described later. . In this case, additional drying is required, and the production efficiency of the nonwoven fabric is deteriorated.

  Thereafter, as shown in FIG. 1, the paper layer 23 is conveyed to a second rotary cylindrical dryer 22 different from the first rotary cylindrical dryer 20. The second rotating cylindrical dryer 22 dries the paper layer 23 sprayed with high-pressure steam until it becomes a non-woven fabric that is a final product. As the second rotating cylindrical dryer 22, for example, a Yankee dryer is used. The second rotating cylindrical dryer 22 is heated to about 150 ° C. by steam, and the paper layer 23 is dried along the surface of the second rotating cylindrical dryer.

  The paper layer 23 after passing through the second rotating cylindrical dryer 22 needs to be sufficiently dried. Specifically, the moisture content of the paper layer 23 after passing through the second rotating cylindrical dryer 22 is preferably 5% or less. In addition, when the moisture content of the paper layer 23 immediately after jetting high-pressure steam is 5% or less, the paper layer 23 jetted with high-pressure steam may not be dried using the second rotating cylindrical dryer 22 or the like. Good.

The paper layer bulk density of the paper layer dried by following the surface of the second rotating cylindrical dryer is preferably 0.10 g / cm ³ or less, more preferably 0.08 g / cm ³ or less. Preferably, it is 0.07 g / cm ³ or less.

  The dried paper layer 23 (nonwoven fabric) is wound up by a winder 21 to obtain a nonwoven fabric.

  FIG. 4 is a schematic cross-sectional view showing the production process of one embodiment of the method for producing a nonwoven fabric according to the present invention. As shown in FIG. 4 (a), a paper layer 23 is formed, and the fibers in the paper layer 23 are entangled by high-pressure water jet, and at this time, the entanglement is more advanced on the surface side (high-pressure water jet surface). A paper layer is formed. Furthermore, on the surface side (high-pressure water flow ejection surface), traces through which the high-pressure water flow has passed are generated as finely shaped irregularities in a streak pattern, and the back surface of the paper layer 23 is slightly uneven.

  As shown in FIG. 4B, the moisture content of the paper layer 23 is reduced to 45% or less by bringing the surface side (high-pressure water jet surface) into contact with the first rotating cylindrical dryer (130 ° C. or higher). Primary drying.

  As shown in FIG. 4 (c), first, on the back side of the paper layer 23 adjusted so that the moisture content is 45% or less by the first rotating cylindrical dryer, the first high-pressure steam spray nozzle 14-1 is used. High-pressure steam (160 ° C or higher) is sprayed and the paper layer is momentarily loosened by the steam pressure. At the same time, the moisture content of the sprayed part in the paper layer 23 is reduced almost uniformly by 5% or more. The rate is adjusted to 40% or less.

  As shown in FIG. 4D, the second high-pressure steam injection nozzle 14 is arranged so that a phase difference appears in the phase and width direction (CD direction) of the pattern of the irregularities formed by the first high-pressure steam injection nozzle. -2 sprays high-pressure steam (175 ° C. or higher) to instantaneously loosen the paper layer partly at the steam pressure, and simultaneously reduces the moisture content of the steam spraying part of the paper layer by 5% or more. The moisture content of the layer 23 is adjusted to 35% or less.

  As shown in FIG. 4 (e), the paper layer 23 having moisture that could not be completely dried by spraying high-pressure steam had a moisture content of the paper layer of the second rotary cylindrical dryer (160 ° C. or higher). It is heat-dried to 5% or less and wound up.

  In order to develop a large uneven shape molding efficiently on both the front and back sides of the paper layer 23, it is performed in two stages in which the phase of the back surface molding and the surface molding is shifted, and the stronger surface of fiber entanglement is higher than the back surface By increasing the number of holes in the vapor pressure or nozzle pattern and increasing the amount of vapor, it is possible to produce a double-sided uneven-type nonwoven fabric with little difference between the front and the back. In addition, as a result, when the whole surface of the paper layer is unraveled with high-pressure steam, the moisture content decreases almost uniformly, and the moisture content unevenness is reduced, so that the drying efficiency is improved and the bulky nonwoven fabric is made efficient. It becomes possible to manufacture well.

  FIG. 5 is a schematic cross-sectional view showing one embodiment of the nonwoven fabric according to the present invention. As shown in FIG. 5, the first concave portion 51 and the first convex portion 52 are formed on the back surface side of the nonwoven fabric 5, and the first concave portion 53 and the first convex portion 54 are formed on the front surface side of the nonwoven fabric 5. Is done. As shown in FIG. 5, the first concave portion and the second concave portion are shifted from each other in the width direction (CD direction) and located on one surface and the other surface, respectively, and the first convex portion and the second convex portion The portions are shifted from each other in the width direction (CD direction) and are located on one surface and the other surface.

  The nonwoven fabric according to the present invention preferably has a DRY cantilever evaluation value of 100 mm or less in the machine direction and the width direction, and more preferably 100 mm or less.

  By cutting the nonwoven fabric produced as described above into a predetermined size, this nonwoven fabric can be used as a dry wipe. Moreover, this nonwoven fabric can be used as a wet wipe by cutting the nonwoven fabric produced as described above into a predetermined dimension and impregnating the nonwoven fabric with a predetermined amount of chemical solution into the fabric.

  Hereinafter, an example for explaining the present invention more concretely is provided. In addition, this invention is not limited to a following example in the range which does not deviate from the objective and the main point.

  First, the evaluation method and measurement method used in Examples 1 to 4 and Comparative Examples 1 to 5 will be described. Paper layer moisture content before high-pressure steam spraying, paper layer moisture content after high-pressure steam spraying, paper layer moisture content after winding, paper layer basis weight, dry thickness, density, dry (DRY) tensile strength, dry (DRY) tensile elongation Degree, wet (WET) tensile strength, wet (WET) tensile elongation, soil removal rate on the high-pressure steam injection surface, and soil removal rate on the high-pressure water jet surface and the high-pressure steam injection surface are as follows: Measurements were made in an environment of temperature and 60% relative humidity.

(Water content of paper layer before high-pressure steam spraying)
The paper layer dried by the first rotating cylindrical dryer 20 is sampled to a size of 30 cm × 30 cm, the outlet weight (W1) of the first rotating cylindrical dryer 20 is measured, and then the sample piece is placed in a constant temperature bath at 105 ° C. After standing for a while and completely drying, the weight (D1) is measured. The moisture content of the paper layer before high-pressure steam spraying is an average value of measured values at N = 10.
Water content of paper layer before high-pressure steam spraying = (W1-D1) / W1 × 100 (%)

(Water content of paper layer after high-pressure steam spraying)
A paper layer in which high-pressure steam is jetted onto a paper layer from one oscillating high-pressure steam nozzle 14 on one suction drum 13 is sampled to a size of 30 cm × 30 cm, and the weight after passing through the oscillating-type high-pressure steam nozzle 14 ( W2) is measured, and then the sample piece is allowed to stand in a constant temperature bath at 105 ° C. for 1 hour and completely dried, and then the weight (D2) is measured. The moisture content of the paper layer after high-pressure steam spraying is an average value of measured values at N = 10.
Paper layer moisture content after high-pressure steam spraying = (W2-D2) / W2 × 100 (%)

(Paper layer moisture content after winding)
The paper layer passed through the second rotating cylindrical dryer 22 is sampled to a size of 30 cm × 30 cm, the weight (W3) after winding is measured, and then the sample piece is placed in a thermostatic bath at 105 ° C. After standing for a while and completely drying, the weight (D3) is measured. The paper layer moisture content after winding is the average value of the measured values at N = 10.
Paper layer moisture content after winding = (W3-D3) / W3 × 100 (%)

(Paper layer weight)
The basis weight of the paper layer was calculated from the absolute dry sample weight (D3) when measuring the moisture content of the paper layer during winding. The paper layer basis weight is an average value of measured values at N = 10.

(Dry thickness)
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 manufactured nonwoven fabric was measured under the measurement conditions of a measurement load of 3 g / cm ² . . Three thicknesses were measured for one measurement sample, and the average value of the three thicknesses was defined as the dry thickness before pressing.

(density)
The dry bulk density was calculated from the basis weight of the paper layer and the dry thickness of the paper layer after the press described above.

(Dry (DRY) tensile strength)
For measurement, a strip-shaped test piece with a width of 25 mm whose longitudinal direction is the machine direction of the paper layer and a strip-shaped test piece with a width of 25 mm whose longitudinal direction is the width direction of the paper layer are cut from the manufactured nonwoven fabric. A sample was prepared. Samples for measurement in the machine direction and width direction are each for three measurements using a tensile tester (manufactured by Shimadzu Corporation, Autograph Model AGS-1kNG) equipped with a load cell with a maximum load capacity of 50N. For the sample, the tensile strength was measured 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 strength of each of the three measurement samples of the measurement sample in the machine direction and the width direction was defined as the dry (DRY) tensile strength in the machine direction and the width direction.

(Dry (DRY) tensile elongation)
For measurement, a strip-shaped test piece with a width of 25 mm whose longitudinal direction is the machine direction of the paper layer and a strip-shaped test piece with a width of 25 mm whose longitudinal direction is the width direction of the paper layer are cut from the manufactured nonwoven fabric. A sample was prepared. Samples for measurement in the machine direction and width direction are each for three measurements using a tensile tester (manufactured by Shimadzu Corporation, Autograph Model AGS-1kNG) equipped with a load cell with a maximum load capacity of 50N. The sample was measured for tensile elongation 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 each of the three measurement samples of the measurement sample in the machine direction and the width direction was defined as the dry (DRY) tensile elongation in the machine direction and the width direction.

(Wet (WET) tensile strength)
A 25 mm wide strip-shaped test piece whose longitudinal direction is the machine direction of the paper layer and a 25 mm wide strip-shaped test piece whose longitudinal direction is the width direction of the paper layer are cut out from the manufactured nonwoven fabric, and a measurement sample Was prepared, and the measurement sample was impregnated with water 2.5 times the mass of the measurement sample (water content magnification: 250%). Then, using the tensile tester (manufactured by Shimadzu Corp., Autograph Model AGS-1kNG) equipped with a load cell with a maximum load capacity of 50N, three samples for measurement in the machine direction and the width direction were used. For the measurement sample, the tensile strength was measured 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 strength of each of the three measurement samples of the measurement sample in the machine direction and the width direction was defined as the wet (WET) tensile strength in the machine direction and the width direction.

(Wet (WET) tensile elongation)
A 25 mm wide strip-shaped test piece whose longitudinal direction is the machine direction of the paper layer and a 25 mm wide strip-shaped test piece whose longitudinal direction is the width direction of the paper layer are cut out from the manufactured nonwoven fabric, and a measurement sample Was prepared, and the measurement sample was impregnated with water 2.5 times the mass of the measurement sample (water content magnification: 250%). Then, using the tensile tester (manufactured by Shimadzu Corp., Autograph Model AGS-1kNG) equipped with a load cell with a maximum load capacity of 50N, three samples for measurement in the machine direction and the width direction were used. For the measurement sample, the tensile elongation was measured 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 each of the three measurement samples of the measurement sample in the machine direction and the width direction was defined as the wet (WET) tensile elongation in the machine direction and the width direction.

(Dirt removal rate on the back of the high-pressure water jet surface and the high-pressure steam jet surface)
The soil removal rate on the surface of the nonwoven fabric on which high-pressure water vapor was jetted (high-pressure water vapor jet surface) was measured by the following procedure. As the nonwoven fabric, WET wipes impregnated with distilled water so as to have a moisture content of 300% (vs. nonwoven fabric (base material mass)) was used.
(1) 12.6% by weight of carbon black (Carbon Black, manufactured by Yoneyama Pharmaceutical Co., Ltd.), 20.8% by weight of beef tallow extremely hardened oil (manufactured by NOF Corporation) and 66.6% by weight of fluid A simulated soil paste containing paraffin (manufactured by Nacalai Tesque) was prepared. The simulated soil paste was diluted with hexane so that the soil paste: hexane (manufactured by Nacalai Tesque Co., Ltd.) was in a weight ratio of 85:15 to prepare a simulated soil agent.
(2) 0.05 ml of the simulated soiling agent was dropped on the prepared slide, and the prepared slide in which the simulated soiling agent was dropped was dried in an atmosphere of a temperature of 20 ° C. and a humidity of 60% for 24 hours.
(3) After drying, using a scanner (Calario GT-750, manufactured by Epson), document type: film, type: positive film, image: 16-bit gray, quality: image quality priority, resolution: 1200 dpi, document size: 68 .6 × 237 mm, output: The image of the slide is captured under the same magnification condition. From the image data of the captured image, the range of 16.9 mm × 16.9 mm in the portion where the simulated stain of the slide is attached The color was calculated. Here, the color was calculated as follows. An image captured by tone correction with a predetermined threshold value set was converted to two gradations. The threshold value for making two gradations was set so that the gradation of the part where the dirt was attached was 0 (black) and the gradation of the part where the dirt was not attached was 255 (white). Then, using Excel 2007 (manufactured by Microsoft), a histogram in which the horizontal axis is gradation and the vertical axis is frequency is created. The frequency of 0 gradation was used as the color.
(4) Wiping of the simulated soiling agent adhering to the preparation with the nonwoven fabric was performed by applying a plastic film- and sheet-friction coefficient test method (JIS-K-7125: 1999). A sample for measurement having a size of 140 × 190 mm was sampled from the manufactured nonwoven fabric, and the sample for measurement was attached to the table of a friction coefficient measuring device (manufactured by Tester Sangyo Co., Ltd.) so that the high-pressure steam spraying surface was on top. At this time, the measurement sample was arranged so that the moving direction of the sliding piece was the direction in which the measurement sample was wiped off (machine direction (MD) or width direction (CD)). After placing the preparation with the simulated soiling agent on the measurement sample so that the surface with the simulated soiling agent contacts the measurement sample, the surface opposite to the surface of the preparation with the simulated soiling material attached Sliding pieces and load cells were attached to the. Then, the coefficient of friction measurement was performed once under the conditions of a feed rate of 150 mm / min and a load of 60 g, thereby wiping the simulated soiling agent adhering to the preparation with the measurement sample.
(5) After wiping off the simulated stain adhering to the slide, the image of the slide is captured under the same conditions using the scanner described above, and the color in the slide before the simulated stain is wiped from the image data of the captured image. The same range of color as the range in which the taste was calculated was calculated.
(6) The color after wiping off the simulated stain adhering to the slide from the color before wiping off the simulated stain adhering to the slide is subtracted from the color before wiping off the simulated stain attached to the slide. The color change rate was calculated by dividing the value. This value was defined as the dirt removal rate of the measurement sample. If the measurement sample has good wiping properties, the simulated stain adhering to the preparation is wiped clean by the measurement sample, so that the color change rate, that is, the stain removal rate increases. On the other hand, if the wiping property of the measurement sample is poor, a lot of the simulated stain remains in the slide where the simulated stain is wiped off by the measurement sample, so that the color change rate, that is, the stain removal rate becomes small. Thus, the ability to wipe off the dirt of the measurement sample can be evaluated by the value of the dirt removal rate. The soil removal rate was measured for three measurement samples, and the average value was taken as the soil removal rate of the measurement sample.

(High-pressure water jet surface and high-pressure steam jet surface, high-pressure water jet surface, back side of high-pressure water jet surface, and dirt removal rate on high-pressure steam jet surface)
Measured so that the high-pressure water jet surface (the surface from which the high-pressure water jet is jetted), the high-pressure steam jet surface, the high-pressure water jet surface, the back surface of the high-pressure water jet surface, and the high-pressure steam jet surface are up The dirt removal rate on the high-pressure water jet surface and the high-pressure steam jet surface was measured by the same method as the stain removal rate on the high-pressure steam jet surface, except that the sample for use was attached.

(DRY cantilever)
A cantilever type test apparatus was used. First, five test pieces each having a size of 25 mm × about 150 mm were collected in the vertical and horizontal directions. Align the short side of the sample surface in parallel with the end of the cantilever type test equipment, move it while holding it lightly with a wooden ruler, and measure the length of the bent one when bent by its own weight (unit: (Integer value) mm). Subsequently, each front and back was measured and the average value was taken.

  Hereinafter, Examples 1-4 and Comparative Examples 1-5 will be described in detail.

Example 1
The nonwoven fabric was manufactured using the nonwoven fabric manufacturing apparatus 1 used by one Embodiment of the method of manufacturing the nonwoven fabric by this invention. A papermaking raw material containing 70% by mass of softwood bleached kraft pulp (NBKP) and 30% by mass of rayon (corona) manufactured by Daiwabo Rayon Co., Ltd. having a fineness of 1.1 dtex and a fiber length of 7 mm was prepared. . And the papermaking raw material was supplied on the paper layer formation belt (Nippon Filcon Co., Ltd. OS80) using the raw material head, and the papermaking raw material was spin-dry | dehydrated using the suction box, and the paper layer was formed. The paper layer moisture content of the paper layer at this time was 80%. Thereafter, a high pressure water stream was jetted onto the paper layer using two high pressure water stream nozzles. The high-pressure water entangling energy of the high-pressure water jet sprayed onto the paper layer using two high-pressure water nozzles was 0.2846 kW / m ² . Here, the high-pressure water flow energy is calculated from the following equation.
High-pressure water entangling energy (kW / m ² ) = 1.63 x injection pressure (kg / cm ² ) x injection flow rate (m ³ / min) / treatment speed (M / min) / 60
Here, the injection flow rate (cubic M / min) = 750 × the total orifice opening area (m ² ) × the injection pressure (kg / cm ² ) ^0.495 .

  Moreover, the distance between the front-end | tip of a high pressure water flow nozzle and the upper surface of a paper layer was 10 mm. As shown in FIG. 5, the nozzle pattern 41 of the high-pressure water flow nozzle had a hole diameter of 92 μm and a nozzle pitch of 0.5 mm.

  The paper layer was transported to two paper layer transport conveyors, and then transported to a first rotating cylindrical dryer 20 (Yankee dryer) heated to about 130 ° C. and dried. The line speed in the first rotating cylindrical dryer 20 (Yankee dryer) was 70. The moisture content of the paper layer was 40%.

  Next, using the first high-pressure water vapor injection nozzle 14-1, high-pressure water vapor is injected onto the surface opposite to the surface of the paper layer 23 on which the high-pressure water flow has been injected, that is, the back surface of the paper layer 23, and then the second The high-pressure steam was jetted onto the surface of the paper layer 23 on which the high-pressure water stream was jetted using the high-pressure steam jet nozzle 14-2. The vapor pressure of the high-pressure steam at this time was 0.5 MPa on the back side of the paper layer and 0.7 MPa on the front side of the paper layer. The steam temperature (high-pressure steam spray nozzle temperature) was 160 ° C. on the back side of the paper layer and 175 ° C. on the front side of the paper layer. The distance between the tip of the vapor nozzle and the upper surface of the paper layer was 2.0 mm. As shown in FIG. 5, the nozzle pattern 42 of the first high-pressure steam spray nozzle and the nozzle pattern 43 of the second high-pressure steam spray nozzle are aligned in the machine direction (in the width direction (CD direction) of the paper layer 23. (MD direction) was arranged with three hole rows, the hole diameter was 500 μm, and the nozzle pitch was a constant 4 mm. Further, as shown in FIG. 5, the nozzle pattern 43 of the second high-pressure steam spray nozzle is directed in the width direction (CD direction) toward the machine direction (MD direction) with respect to the nozzle pattern 42 of the first high-pressure steam spray nozzle. ) To the left, and the phase difference of the deviation was 2 mm. The suction force with which the suction drums 13-1 and 13-2 suck the paper layer was -5 kPa. A stainless steel 18 mesh perforated sleeve was used on the outer periphery of the suction drum. The moisture content of the paper layer 23 was reduced by 5% or more, and the moisture content of the paper layer was 35%.

  The paper layer was transported to a second rotating cylindrical dryer 22 (Yankee dryer) heated to about 160 ° C. and dried. The line speed in the second rotating cylindrical dryer 22 (Yankee dryer) was 70 m / min (← Are you sure?). The moisture content of the paper layer after drying was 5%. From the above, a nonwoven fabric was obtained.

(Example 2)
A nonwoven fabric was obtained by the same manufacturing method as in Example 1 except that the vapor pressure of the second high-pressure steam injection nozzle 14-2 was 0.5 MPa.

(Example 3)
A nonwoven fabric was obtained by the same manufacturing method as in Example 1 except that the vapor pressure of the first high-pressure steam injection nozzle 14-1 was 0.8 MPa and the pore diameter was 400 μm.

Example 4
The first high-pressure steam jet nozzle 14-1 is used to jet high-pressure steam onto the surface of the paper layer 23 on which the high-pressure water stream has been jetted, and the second high-pressure steam jet nozzle 14-2 is used to produce high-pressure steam. The water flow is jetted onto the surface opposite to the surface of the paper layer 23, that is, the back surface of the paper layer 23, and the vapor pressure of the first high-pressure steam jet nozzle 14-2 is 0.7 MPa, and the second high-pressure steam jet A nonwoven fabric was obtained by the same production method as in Example 1 except that the vapor pressure of the nozzle 14-2 was 0.5 MPa.

(Example 5)
The vapor pressure of the first high-pressure steam spray nozzle 14-1 is 0.4 MPa, and the holes of the nozzle pattern 42 of the first high-pressure steam spray nozzle 14 are arranged in the width direction (CD direction) of the paper layer 23 in the machine direction (MD 2) in the direction), the hole diameter is 500 μm, the nozzle pitch is a constant pitch of 2.0 mm, the vapor pressure of the second high-pressure steam injection nozzle 14-1 is 0.5 MPa, the second The holes of the nozzle pattern 43 of the high-pressure steam spray nozzle are arranged in a row in the width direction (CD direction) of the paper layer 23 and in two rows in the machine direction (MD direction), the hole diameter is 500 μm, and the nozzle pitch is A nonwoven fabric was obtained by the same production method as in Example 1 except that the pitch was constant at 2.0 mm.

(Example 6)
The first high-pressure steam jet nozzle 14-1 is used to jet high-pressure steam onto the surface of the paper layer 23 on which the high-pressure water stream has been jetted, and the second high-pressure steam jet nozzle 14-2 is used to produce high-pressure steam. A nonwoven fabric was obtained by the same manufacturing method as in Example 1 except that the water flow was jetted onto the opposite side of the surface of the paper layer 23, that is, the back side of the paper layer 23.

(Comparative Example 1)
A non-woven fabric was obtained by the same manufacturing method as in Example 1 except that the step of injecting high-pressure steam was not performed (except that the high-pressure steam was not injected).

(Comparative Example 2)
The high-pressure steam was not jetted onto the surface of the paper layer 23 on which the high-pressure water stream was jetted using the second high-pressure steam jet nozzle 14-2 (high pressure using only the first high-pressure steam jet nozzle 14-1). A nonwoven fabric was obtained by the same production method as in Example 1 except that water vapor was jetted onto the opposite side of the surface of the paper layer 23 on which the high-pressure water stream was jetted, that is, the back side of the paper layer 23.

(Comparative Example 3)
The non-woven fabric was manufactured by the same manufacturing method as in Example 1 except that the nozzle pattern 42 of the first high-pressure steam spray nozzle and the nozzle pattern 43 of the second high-pressure steam spray nozzle were not shifted and the phase difference was 0 mm. Obtained.

  The production conditions of Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 1.

  In Examples 1 to 6 and Comparative Examples 1 to 3, the paper layer moisture content before high-pressure steam spraying, the paper layer moisture content after high-pressure steam spraying, the paper layer moisture content after winding, the paper layer basis weight, the dry thickness, the density, Table 2 shows the measurement results of dry (DRY) tensile strength, dry (DRY) tensile elongation, wet (WET) tensile strength, wet (WET) tensile elongation, and DRY cantilever.

  Table 3 shows the measurement results of the dirt removal rate in Example 1, Comparative Example 1 and Comparative Example 2.

(Evaluation results)
In the nonwoven fabrics obtained in Examples 1 to 6, the phase of the concave pattern on the back surface is different from the phase of the concave pattern on the front surface, and the phase of the convex pattern on the back surface is the phase of the convex pattern on the front surface. Since they are different, it was found that they have bulkiness, flexibility, strength, excellent wiping properties, and excellent pop-up properties (handling properties).

  The nonwoven fabric obtained in Examples 1-6 was compared with each of the nonwoven fabric obtained in Comparative Examples 1-3. It has confirmed that the nonwoven fabric obtained in Examples 1-6 has bulkiness with respect to the nonwoven fabric obtained in Comparative Example 1. The nonwoven fabric obtained in Comparative Example 1 was formed with small irregularities with fine nozzle streak traces due to high-pressure hydroentanglement, but only advanced the interentanglement of fibers. It was confirmed that the nonwoven fabrics obtained in Examples 1 to 6 were bulky with respect to the nonwoven fabric obtained in Comparative Example 2. Since the non-woven fabric obtained in Comparative Example 2 is sprayed with high-pressure steam only on the back surface of the paper layer, the bulkiness effect is slightly low, and the difference between the surface and the back surface in the molded state due to the concavo-convex portion is different from Example 1. It became slightly larger than the nonwoven fabric obtained in ~ 6. The nonwoven fabrics obtained in Examples 1 to 6 were found to have strength and bulkiness with respect to the nonwoven fabric obtained in Comparative Example 3. That is, in the nonwoven fabrics obtained in Examples 1 to 6, the phase of the concave pattern on the surface of the paper layer is different from the phase of the concave pattern on the back surface, and the phase of the convex pattern on the surface of the paper layer is the back surface. The phase of the concave pattern on the surface of the paper layer is the same as the phase of the concave pattern on the back surface, and the nonwoven fabric obtained in Comparative Example 3 is different from the phase of the concave pattern of Since the phase of the pattern of the convex portions on the surface of the paper layer is the same as the phase of the pattern of the concave portions on the back surface, the nonwoven fabric obtained in Examples 1 to 6 is not significantly strong and has a raised effect. Was also low.

The nonwoven fabric obtained in Example 1 was compared with each of the nonwoven fabric obtained in Examples 2-6.
In Example 2, the vapor pressure of the second high-pressure steam injection nozzle 14-2 is 0.5 MPa, whereas in Example 1, the vapor pressure of the second high-pressure steam injection nozzle 14-2 is 0.7 MPa. Therefore, the fibers on the surface of the paper layer, which is the hydroentangled surface, are thoroughly loosened, and the nonwoven fabric obtained in Example 1 is more bulky than the nonwoven fabric obtained in Example 2. It was. In Example 3, the pore diameter of the first high-pressure steam jet is 400 μm, but the steam pressure is 0.8 MPa, so the nonwoven fabric obtained in Example 3 is equivalent to the nonwoven fabric obtained in Example 1 It was bulky. In Example 4, since the high pressure water vapor | steam of 0.7 Mpa was sprayed on the surface of the paper layer 23 in which the high pressure water flow was injected using the 1st high pressure water vapor | steam injection nozzle 14-1, it comes out bulky. Due to the buffering effect, it is considered that the efficiency of raising is slightly lower than that in Example 1 during the subsequent medium pressure (0.5 MPa) treatment on the back side of the paper layer. In Example 5, since the nozzle pitch of the nozzles of the first high-pressure steam injection nozzle 14-1 and the second high-pressure steam injection nozzle 14-2 is 2 mm, the entire surface of the nonwoven fabric is sprayed and the load on the nonwoven fabric is in Example 1. It becomes slightly larger than the obtained nonwoven fabric, and its strength is slightly lowered. In Example 6, the first high-pressure steam spray nozzle 14-1 is used to spray high-pressure steam having a steam pressure of 0.5 MPa onto the surface of the paper layer 23 on which the high-pressure water stream has been sprayed. Compared with the nonwoven fabric obtained in Example 1 without loosening the fiber entanglement on the surface, the swelling effect and the softening effect were slightly low.

  As is apparent from Table 3, the results of the soil removal rate of the nonwoven fabric obtained in Example 1 relative to the nonwoven fabric obtained in Comparative Example 1 and Comparative Example 2 are both on the front and back surfaces of the nonwoven fabric obtained in Example 1. The dirt removal rate was high and the wiping property was good.

  7 is a photomicrograph showing the front and back surfaces of the nonwoven fabric obtained in Example 1, the nonwoven fabric obtained in Comparative Example 1, and the nonwoven fabric obtained in Comparative Example 2. FIG. Since the non-woven fabric obtained in Example 1 is out of phase so that the sprayed portions of high-pressure steam do not overlap on the front and back surfaces of the non-woven fabric, an uneven mold is developed on both sides, and the unevenness between the front and back surfaces I can understand that there are few. On the other hand, since the nonwoven fabric obtained in Comparative Example 1 is only jetted with high-pressure water flow onto the surface, the unevenness on the front and back surfaces of the nonwoven fabric is different between the high-pressure water nozzle trace on the front side and the nozzle trace and wire pattern on the back side. large. The non-woven fabric obtained in Comparative Example 1 has a high-pressure steam sprayed surface on the back side of the non-woven fabric, which is greatly uneven, but the back side of the non-woven fabric is not shaped so much, and the unevenness between the front and back surfaces is large. I understand that.

DESCRIPTION OF SYMBOLS 1 The apparatus which manufactures a nonwoven fabric 5 Nonwoven fabric 11 Raw material supply head 12 High pressure water flow nozzle 13-1 1st suction drum 13-2 2nd suction drum 14-1 1st high pressure steam injection nozzle 14-2 2nd high pressure steam injection nozzle 15 Suction Box 16 Paper layer forming conveyor 17 Suction pickup 18 First paper layer conveying conveyor 19 Second paper layer conveying conveyor 20 First rotating cylindrical dryer 21 Winder 22 Second rotating cylindrical dryer 23 Paper layer 31 High-pressure steam 32 Recessed portion 33 Convex part 34 Concave part 35 Convex part 41 Nozzle pattern of high-pressure water flow nozzle 42 Nozzle pattern of first high-pressure water vapor injection nozzle 43 Nozzle pattern of second high-pressure water vapor injection nozzle 51 First concave part 52 First convex part 53 Second concave part 54 Second Convex

Claims (9)

Supplying a papermaking raw material containing moisture onto a belt moving in one direction, and forming a paper layer having at least two surfaces on the belt;
Spraying high-pressure steam onto each of the at least two surfaces of the paper layer formed on the belt using a first high-pressure steam spray nozzle and a second high-pressure steam spray nozzle;
A method for producing a nonwoven fabric, comprising:
The step of injecting the high-pressure water vapor extends in the machine direction and is intermittently arranged in the width direction on one surface of the at least two surfaces of the paper layer using the first high-pressure water vapor injection nozzle. Forming a first recess and a first protrusion, and extending in the machine direction to the other of the at least two surfaces of the paper layer using the second high-pressure steam spray nozzle and intermittent in the width direction A second concave portion and a second convex portion that are arranged side by side, the phase of the pattern of the first concave portion is different from the phase of the pattern of the second concave portion, and the phase of the pattern of the first convex portion is the first It is a process different from the phase of the pattern of the two convex portions.
A method of manufacturing a nonwoven fabric. Supplying a papermaking raw material containing moisture onto a belt moving in one direction, and forming a paper layer having at least two surfaces on the belt;
Spraying high-pressure steam onto each of the at least two surfaces of the paper layer formed on the belt using a first high-pressure steam spray nozzle and a second high-pressure steam spray nozzle;
A method for producing a nonwoven fabric, comprising:
The step of injecting the high-pressure steam divides the distance of the full length portion of the first high-pressure steam injection nozzle into two equal parts, the position of the first virtual center line parallel to the machine direction, and the second high-pressure steam The first high-pressure steam spray nozzle is bisected so that the distance of the full length portion of the spray nozzle in the width direction is different from the position of the second virtual center line parallel to the machine direction in the width direction. Disposing in one surface direction of the at least two surfaces of the paper layer, and disposing the second high-pressure steam spray nozzle in the other surface direction of the at least two surfaces of the paper layer. Is,
A method of manufacturing a nonwoven fabric.   In the step of injecting the high-pressure steam, the vapor pressure of the high-pressure steam is 0.2 MPa or more and 1.5 MPa or less, and the suction force of the suction drum or the belt is -1 kPa or more. A method for producing the nonwoven fabric described in 1.   The moisture content of the paper layer after the step of jetting the high-pressure steam is 0% or more and 40% or less, and at least 5% lower than the moisture content of the paper layer before the step of jetting the high-pressure steam. Item 4. A method for producing the nonwoven fabric according to any one of Items 1 to 3.   The method for producing a nonwoven fabric according to any one of claims 1 to 4, wherein a vapor pressure of the other surface of the paper layer is equal to or greater than a vapor pressure of the one surface of the paper layer. .   After the step of forming the paper layer on the belt, a high-pressure water stream is jetted onto one of the at least two surfaces of the paper layer formed on the belt and extends in the machine direction. The method for producing a nonwoven fabric according to any one of claims 1 to 5, further comprising a step of forming grooves on the one side of the paper layer intermittently arranged in the width direction.   After the step of injecting the high-pressure water stream, the paper layer to which the high-pressure water stream has been jetted is first rotated so that the paper layer to which the high-pressure water stream has been jetted has a moisture content of 10% to 45%. The method for producing a nonwoven fabric according to claim 6, further comprising a step of drying by following the surface of the cylindrical dryer. Drying the paper layer on which the high-pressure water vapor has been jetted along the surface of a second rotating cylindrical dryer;
Winding up the dried paper layer;
Further including
The moisture content of the paper layer after winding of the dried paper layer is 5% or less,
A method for producing the nonwoven fabric according to any one of claims 1 to 7. The paper layer bulk density of the dried paper layer is 0.10 g / cm ³ or less by causing the paper layer sprayed with the high-pressure steam to be along the surface of the second rotating cylindrical dryer. Item 9. A method for producing the nonwoven fabric according to Item 8.