TW201348546A - Non-woven fabric and method for producing non-woven fabric - Google Patents

Abstract

Provided is a method for producing a non-woven fabric enabling a high-strength, bulky, and flexible non-woven fabric to be obtained. This method for producing a non-woven fabric comprises the following: a step (16) for feeding a raw paper material, which includes moisture and latently crimpable fiber, onto a belt that moves in one direction, and forming a paper layer on the belt; a step (12, 15) for spraying one side of the paper layer with a high-pressure water flow to form a first groove extending in a mechanical direction on the one side; a step (20) for drying the paper layer that was sprayed with the high-pressure water flow, so that the moisture percentage reaches 10 to 45%; and a step (13, 14) for spraying the other side of the dried paper layer with a high-pressure water vapor from a vapor nozzle to form on the other side of the paper layer a second groove that is wider than the first groove and that extends in the mechanical direction, and to cause crimping of the latently crimpable fiber of the paper layer. Also, this non-woven fabric is produced by this method for producing a non-woven fabric.

Description

Non-woven fabric and non-woven fabric manufacturing method

The present invention relates to nonwoven fabrics, and more particularly to nonwoven fabrics suitable for use in wipes. Further, the present invention relates to a method of manufacturing the above nonwoven fabric.

A method for producing a bulky paper which is well known in the prior art, characterized in that a fiber sheet having a water content of 50 to 85% by weight is transferred to an open mesh net around the suction portion, and the fiber sheet is held The fiber sheet is attracted to the state of the mesh on the perforated mesh, and at the same time as or before the attraction, water flakes having a heat of 5 kcal/kg or more are sprayed on the fiber sheet to form and open the mesh of the fiber sheet. The pattern corresponding to the web is dried in the drying step to thereby obtain a embossed paper to which a pattern is imparted (for example, Patent Document 1). By the method for producing the bulky paper, it is possible to produce a bulky paper having a large thickness, high absorbability, good flexibility, and moderately firmness.

[Previous Technical Literature] [Patent Document]

Patent Document 1 Japanese Patent No. 3461122

The volume of the nonwoven fabric which is improved as compared with the conventional manufacturing method, such as the manufacturing method described in the patent document 1, is the pressure which is not woven by the nonwoven fabric in the subsequent steps, such as a cutting process, a winding process, etc. of a cutting machine. There is a situation where the flattening becomes lower. Therefore, it is expected that the pressure is applied to the non-woven fabric, and after the applied pressure is released, the large-sized non-woven fabric can be maintained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide that a pressure is applied to a nonwoven fabric and that a higher volume nonwoven fabric and a method of manufacturing the nonwoven fabric can be maintained after the applied pressure is released.

In order to solve the above problems, the present invention adopts the following configuration.

In other words, the manufacturing method of the nonwoven fabric of the present invention has a step of supplying a papermaking raw material containing moisture and a latent crimping fiber to a belt body that moves toward one direction, and forming a paper layer on the belt body; a step of spraying a high-pressure water stream on one side of the paper layer, forming a first groove extending in the machine direction on the one side, and drying the paper layer having the high-pressure water stream to a moisture content of 10 to 45%; and The steam nozzle sprays high-pressure water vapor on the other side of the dried paper layer, thereby forming a surface on the other side of the paper layer There is a step in which the width of the first groove is larger than the width of the first groove, the second groove extending in the machine direction, and the crimping of the latent fibers of the paper layer is presented.

Further, the nonwoven fabric of the present invention contains a latent crimpable fiber, and has a plurality of first groove portions extending in one direction and arranged in a direction perpendicular to the one direction on one surface, and having a one-way direction on the other surface The plurality of second groove portions extending in a direction perpendicular to the unidirectional direction and having a width larger than the width of the first groove portion, the crimping fibers present on the surface of the second groove portion are curled up, and there is a first The crimping of the potentially crimped fibers on the face of the groove is large.

According to the present invention, it is possible to obtain a pressure which is applied to the non-woven fabric, and after the applied pressure is released, a large-sized non-woven fabric can be maintained.

1‧‧‧Nonwoven manufacturing equipment

11‧‧‧Material supply head

12‧‧‧High pressure water jet nozzle

13‧‧‧Attraction roller

14‧‧‧Vapor nozzle

15‧‧‧Attraction box

16‧‧‧Paper layer forming conveyor

17‧‧‧Attracting pickers

18,19‧‧‧Paper handling conveyor

20,22‧‧‧dryer

21‧‧‧Winding machine

23‧‧‧paper layer

31‧‧‧High pressure water flow

32‧‧‧Ditch

41‧‧‧Paper layer forming belt

51‧‧‧High pressure water vapor

52‧‧‧Ditch

Fig. 1 is a view for explaining a nonwoven fabric manufacturing apparatus using a method of manufacturing a nonwoven fabric according to an embodiment of the present invention.

Fig. 2 is a view showing an example of a high pressure water jet nozzle.

Fig. 3 is a view showing an example of a nozzle hole of a high pressure water flow nozzle.

Fig. 4 is a view for explaining the principle of entanglement of fibers of a paper layer by a high pressure water flow.

Figure 5 is a section of the width of the paper layer that is sprayed with high pressure water. Figure.

Fig. 6 is a view showing an example of a high pressure water vapor nozzle.

Fig. 7 is a view showing an example of a nozzle hole of a high-pressure steam nozzle.

Fig. 8 is a view for explaining the principle of the fiber of the paper layer being unwound by the high-pressure water vapor, the volume of the paper layer becoming large, and the fiber of the paper layer being crimped.

Fig. 9 is a cross-sectional view in the width direction of a paper layer on which high-pressure water vapor is sprayed.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. A method of manufacturing a non-woven fabric. Fig. 1 is a view for explaining a nonwoven fabric manufacturing apparatus 1 using a method of manufacturing a nonwoven fabric according to an embodiment of the present invention.

The papermaking raw material is supplied to the raw material supply head 11. Being supplied to The papermaking raw material of the raw material supply head 11 is supplied from the raw material supply head 11 to the paper layer forming belt of the paper layer forming conveyor 16, and is deposited on the paper layer forming belt. The paper layer forming belt is preferably a support having a gas permeability through which steam can pass. For example, a metal mesh, a felt, or the like can be used as a paper layer forming tape.

The fiber supplied to the raw material supply head 11 is used in the raw material of the papermaking material. The dimension is preferably a short fiber having a fiber length of 20 mm or less. Examples of the short fibers include wood pulp of chemical pulp of conifer or hardwood, semi-chemical pulp and mechanical pulp, mercerized pulp which chemically treats the wood pulp, and non-wood of crosslinked fibers, hemp or cotton. Fiber and ruthenium Examples of cellulose fibers such as regenerated fibers such as rayon fibers, and synthetic fibers such as polyethylene fibers, polypropylene fibers, polyester fibers, and polyamide fibers are exemplified.

The papermaking raw material contains potentially crimped fibers. Potential volume The shrinkable fiber is a crimped fiber upon heating. The crimping of the latent crimping fibers takes advantage of the cross-sectional anisotropy of the fibers. In the case of the latent crimping fiber, for example, a side-by-side type composite fiber in which a high shrinkage component and a low shrinkage component are arranged side by side, and a core having a high shrinkage component as a core and a low shrinkage component are used as a sheath. The eccentric core-sheath type composite fiber of the core and the sheath is disposed in such a manner that the center of gravity of the two components is not superimposed on one point. When the potentially crimped fibers are crimped, the potentially crimped fibers are, for example, crimped into a spiral. The latent crimp fibers are made of, for example, polyester, polypropylene, or the like.

Relative to the weight of all the fibers contained in the papermaking material, The proportion of the latent crimpable fibers in the papermaking raw material is preferably 5% by weight or more and 80% by weight or less. When the proportion of the latent crimpable fibers in the papermaking raw material is less than 5% by weight, it may be difficult to uniformly disperse the latent crimpable fibers in the paper layer. Further, when the proportion of the latent crimpable fibers in the papermaking raw material is more than 80% by weight, the texture unevenness may occur on the produced non-woven fabric, or the fiber entanglement by the high-pressure water flow described later may be weakened. Therefore, the non-woven fabric according to an embodiment of the present invention preferably contains 5% by weight or more and 80% by weight or less of the potential crimping fiber with respect to the weight of all the fibers contained in the nonwoven fabric. The potential crimping fiber system in the non-woven fabric comprises: the fiber which has been crimped by the heat treatment of the step of manufacturing the non-woven fabric, and the strong entanglement with each other by the fiber even by the heat treatment Unable to present the crimped fibers.

Papermaking material deposited on the paper layer forming belt by the suction box 15 is suitably dehydrated to form a paper layer 23. The paper layer 23 passes between two high-pressure water flow nozzles 12 disposed on the paper layer forming belt, and two suction boxes 15 disposed at positions facing the high-pressure water flow nozzle 12 with the paper layer forming belt interposed therebetween. The suction box 15 collects water sprayed from the high pressure water flow nozzle 12. The high-pressure water jet nozzle 12 injects the high-pressure water jet onto the paper layer 23, and a groove portion is formed on the upper surface (the surface on the high-pressure water flow nozzle 12 side, and the surface on which the high-pressure water jet is sprayed below is referred to as a high-pressure water jet ejection surface).

One of the high pressure water jet nozzles 12 is exemplified in Fig. 2. high pressure The water flow nozzle 12 ejects a plurality of high-pressure water streams 31 arranged in the width direction (CD) of the paper layer 23 toward the paper layer 23. As a result, a plurality of groove portions 32 extending in the width direction (CD) of the paper layer 23 and extending in the machine direction (MD) are formed on the upper surface of the paper layer 23.

An example of the nozzle hole of the high pressure water jet nozzle 12 is shown in the third Figure. The nozzle holes 121 of the high-pressure water jet nozzle 12 are arranged in a line in the width direction (CD) of the paper layer, for example. The nozzle hole 121 preferably has a diameter of 90 to 150 μm. When the diameter of the nozzle hole 121 is less than 90 μm, the nozzle may be clogged. Further, when the diameter of the nozzle hole 121 is larger than 150 μm, the processing efficiency may be deteriorated.

Hole spacing of the nozzle holes 121 (in the width direction (CD) phase The distance between the centers of the adjacent holes is preferably 0.5 to 1.0 mm. When the hole pitch of the nozzle hole 121 is less than 0.5 mm, there is a fear that the pressure resistance of the nozzle is lowered and damage is caused. In addition, the hole pitch of the nozzle hole 121 is greater than 1.0 mm. At the time, there is a case where the fiber entanglement is insufficient.

When the paper layer 23 is subjected to a high-pressure water flow, as shown in Fig. 2 The layer 23 is formed with the groove portion 32 and the fibers of the paper layer 23 are intertwined with each other, so that the strength of the paper layer 23 becomes high. When the paper layer 23 is subjected to a high-pressure water flow, the principle of the fibers of the paper layer 23 interlacing with each other will be described with reference to Fig. 4 . However, this principle does not limit the invention.

As shown in Fig. 4, high pressure is applied from the high pressure water flow nozzle 12. When the water stream 31 is ejected to the paper layer 23, the high pressure water stream 31 passes through the paper layer forming belt 41. The fibers of the paper layer 23 are thereby brought to the center by the portion 42 of the paper layer forming belt 41 by the high pressure water stream 31. As a result, the fibers of the paper layer 23 are gathered toward the high-pressure water stream 31 through the portion 42 of the paper layer forming belt 41 to entangle the fibers with each other.

The paper layer 23 is strong by the fibers of the paper layer 23 intertwined with each other. The degree becomes high, whereby in the subsequent step, even if the high-pressure water vapor is sprayed on the paper layer 23, the paper layer 23 is perforated, the paper layer 23 is broken, and the scattering is reduced. Further, the papermaking raw material can increase the wet strength of the paper layer 23 without adding a paper strength enhancer.

Passing the paper layer 23 through two high pressure water jet nozzles 12, and two A schematic view of a cross section in the width direction at a position after the stage between the suction boxes 13 (the position of the symbol 24 in Fig. 1) is shown in Fig. 5. The groove portion 32 is formed on the high-pressure water jet ejection surface of the paper layer 23 by a high-pressure water flow. On the surface opposite to the high pressure water jet surface of the paper layer 23, a pattern (not shown) corresponding to the pattern of the paper layer forming belt is formed.

Thereafter, as shown in Fig. 1, the paper layer 23 is attracted by suction. The pickup 17 is transferred to the paper layer conveyance conveyor 18. Further, the paper layer 23 is transferred to the paper layer conveyance conveyor 19 and then transferred to the dryer 20.

The dryer 20 dries the paper layer 23. Dryer 20 For example, a Yankee dryer is used. The dryer 20 causes the paper layer 23 to be dried by attaching a high-pressure water jet surface of the paper layer 23 to a drum heated to about 110 ° C by steam.

The entire paper layer 23 after drying by the dryer 20 The water content is preferably from 10 to 45%, more preferably from 20 to 40%. Here, the water content means the amount of water contained in the paper layer when the dry mass of the paper layer 23 is set to 100%.

When the water content of the paper layer 23 is less than 10%, there is a paper layer 23 The hydrogen bonding between the fibers becomes strong, and the energy required to unwind the fibers of the paper layer 23 by the high-pressure steam described later becomes extremely high. In addition, the curling of the latent crimping fibers in the paper layer 23 causes the paper layer 23 to become dry, and in order to make the hydrogen bonding between the fibers of the paper layer 23 stronger, the fibers of the paper layer 23 are less likely to move, or The case where the crimping of the latent crimping fibers in the paper layer 23 is difficult to present.

On the other hand, when the water content of the paper layer 23 is more than 45%, There is a case where the energy required to dry the paper layer 23 to a predetermined water content or less is extremely high in order to use the high-pressure steam described later. Further, the heat imparted to the paper layer 23 by the high-pressure steam described later is mostly used to raise the temperature of the water in the paper layer 23 or to evaporate the water in the paper layer 23, and the temperature of the paper layer 23 is present. The case where the temperature at which the crimping of the latent crimpable fibers in the paper layer 23 is sufficiently exhibited is not reached.

The high pressure water jet surface of the paper layer 23 is attached to the dryer 20 The drum is heated to the high pressure water jet surface of the paper layer 23, whereby the paper layer 23 is dried. Therefore, the water content of the high pressure water jet surface portion of the paper layer 23 is smaller than the water content of the entire paper layer 23. Therefore, in the portion of the high-pressure water jet surface, the hydrogen bonding between the fibers of the paper layer 23 becomes strong, and the fibers of the portion of the high-pressure water jet ejection surface become less movable, so that there is a portion of the high-pressure water jet surface of the paper layer 23. A situation in which the shrinkage of a potentially crimped fiber is difficult to present.

Next, the paper layer 23 is attached to the cylindrical suction roller 13 The mesh-like outer peripheral surface moves. At this time, one steam nozzle 14 disposed above the outer peripheral surface of the suction drum 13 sprays high-pressure water vapor on the paper layer 23. The suction drum 13 is internally provided with a suction device, and the water vapor sprayed from the steam nozzle 14 is sucked by the suction device. The high-pressure water vapor sprayed from the steam nozzle 14 is formed on the upper surface of the paper layer 23 (the surface on the side of the steam nozzle 14 and the surface opposite to the high-pressure water jet surface) to form a groove portion having a width larger than that formed by the high-pressure water flow. Larger ditch. In addition, the latent crimping fibers in the paper layer 23 are crimped by the high pressure water vapor sprayed from the vapor nozzles 14.

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

The temperature of the high-pressure water vapor sprayed from the steam nozzle 14 Better than the temperature of the crimping of the potentially crimped fibers in the paper layer Above °C high. Thereby, the crimping of the latent crimping fibers in the paper layer can be exhibited by spraying high pressure water vapor on the paper layer. For example, the temperature of the high-pressure steam sprayed from the steam nozzle 14 is preferably 115 to 250 °C. When the temperature of the high-pressure water vapor sprayed from the vapor nozzle 14 is lower than 115 ° C, there is a case where the crimping of the latent crimpable fibers in the paper layer does not occur. When the temperature of the high-pressure water vapor sprayed from the steam nozzle 14 is higher than 250 ° C, there is a curling of the latent crimping fibers in the paper layer formed on the surface of the paper layer by the high-pressure water vapor, or potential crimping property. The fiber is melted and melted, and it is difficult to form a groove on the surface of the paper layer.

In addition, in order not to spray the high-pressure water vapor after the paper layer 23 The water content is greater than the moisture content of the paper layer 23 before the high pressure water vapor is sprayed, and preferably the temperature of the high pressure water vapor is higher than the temperature of the dryer 20. Thereby, the drying of the paper layer 23 is carried out when the high-pressure water vapor is ejected from the paper layer 23, and the paper layer 23 is dried while being bulky. Since the hydrogen bonding of the fibers of the paper layer 23 becomes stronger when the paper layer 23 is dried, the strength of the paper layer 23 is increased, and the bulky paper layer 23 is less likely to be crushed. Moreover, since the latent crimping fiber in the paper layer 23 is curled, the volume of the paper layer 23 becomes larger, and it is less likely to be crushed. Further, by the strength of the paper layer 23 being increased, it is possible to prevent the paper layer 23 from being perforated and broken by the injection of the high-pressure water vapor.

Figure 6 shows the arrangement above the suction drum 13 An example of the steam nozzle 14. The steam nozzle 14 sprays a plurality of high-pressure water vapors 51 arranged in the machine direction (MD) and the width direction (CD) of the paper layer 23 toward the paper layer 23. As a result, the paper layer 23 is formed on the paper sheet 23 in the width direction and in the machine direction (MD). The plurality of groove portions 52 are extended. As described above, the width of the groove portion 52 is larger than the width of the groove portion 32 (see FIG. 2) formed by the high-pressure water flow 31.

a plurality of jets of vapor nozzles 14 arranged in the width direction (CD) Since the nozzle holes are arranged in three rows in the machine direction (MD), as shown in Fig. 6, the plurality of high-pressure water vapors 51 arranged in the width direction (CD) are arranged in three rows in the machine direction (MD). However, the number of columns in which the plurality of nozzle holes arranged in the width direction (CD) are arranged in the machine direction (MD) is not limited to three columns, and may be one column, two columns, or four columns or more. For example, as in the vapor nozzle 14A shown in Fig. 7(a), the plurality of nozzle holes 141A arranged in the width direction (CD) may be arranged in six rows in the machine direction (MD). Fig. 7 is a view showing an example of a nozzle hole of a high-pressure steam nozzle. Further, as shown in FIG. 7(b), in order to arrange a plurality of nozzle holes 141B arranged in the width direction (CD), a plurality of columns (for example, six columns) may be arranged in the machine direction (MD), and may be arranged in the width direction. The plurality of nozzle holes 141B of (CD) are arranged in two rows of high-pressure water vapor nozzles 14B in the machine direction (MD), and a plurality of columns (for example, three columns) are arranged in the machine direction (MD).

The nozzle hole of the steam nozzle 14 preferably has a diameter of 150~ 500 μm. When the diameter of the nozzle hole is less than 150 μm, there is a problem that the energy is insufficient and the fiber cannot be sufficiently removed. Further, when the pore diameter of the vapor nozzle 14 is larger than 500 μm, there is a problem that the energy is too large and the substrate is excessively damaged.

Hole spacing of the nozzle holes (adjacent to the width direction (CD) The distance between the centers of the nozzle holes is preferably 1.0 to 5.0 mm. Nozzle hole When the hole pitch is less than 1.0 mm, there is a fear that the withstand voltage of the steam nozzle 14 is lowered and damage is caused. Further, when the hole pitch of the nozzle holes is larger than 5.0 mm, the effect of improving the flexibility may be lowered due to insufficient processing.

When the paper layer 23 is sprayed with high-pressure water vapor, the fiber of the paper layer 23 The dimension is unwound and then the volume of the paper layer 23 is made larger. Thereby, the softness of the paper layer 23 is improved, and the touch of the paper layer 23 is improved. Moreover, when high pressure water vapor is sprayed onto the paper layer 23, the crimping of the latent crimping fibers in the paper layer 23 is exhibited. Thereby, pressure is applied to the paper layer 23, and the large volume of the paper layer 23 can be maintained even after the applied pressure is released. When the paper layer 23 is subjected to high-pressure water vapor, the fiber of the paper layer 23 is unwound, the volume of the paper layer 23 is increased, and the principle of curling of the latent crimping fibers in the paper layer 23 is described with reference to FIG. . However, this principle does not limit the invention.

When the steam nozzle 14 sprays the high-pressure steam 51 as shown in Fig. 8(a), the high-pressure steam 51 comes into contact with the suction drum 13. Most of the high pressure water vapor 51 is bounced back to the suction drum 13. Thereby the fibers of the paper layer 23 are rolled up and then unwound. In particular, on the opposite side of the high-pressure water jet ejection surface, the fibers are not strongly entangled as in the high-pressure water jet ejection surface, so that it is easy to eject the high-pressure water vapor 51 by spraying the high-pressure water vapor 51 on the opposite side of the high-pressure water jet ejection surface. Then, the fibers of the unwound paper layer 23 are separated by the high-pressure water vapor 51 to form a groove in the paper layer 23. The fiber to be removed is moved toward the width direction side of the portion 53 where the high-pressure steam 51 contacts the paper layer 23, so that the volume of the paper layer 23 becomes high. The moisture contained in the paper layer 23 is evaporated by the heat of the high-pressure steam 51 and removed from the paper layer.

In order to increase the volume of the paper layer, high pressure water vapor is used in the paper. Since the layer forms the groove portion, the width of the groove portion formed by the high-pressure water vapor is larger than the width of the groove portion formed by the high-pressure water flow.

Moreover, as shown in Fig. 8(b), steaming by high pressure water The heat of the gas 51, the latent crimping fibers 121 in the paper layer 23 are heated to cause the crimping of the potentially crimpable fibers 121 in the paper layer 23. Thereby, the paper layer 23 which becomes high in height is not easily crushed. Further, the pressure is applied to the non-woven fabric, and the large volume of the paper layer 23 can be maintained even after the applied pressure is released. Moreover, even if the paper layer becomes wet, the volume of the raised paper layer 23 is not easily crushed. The fibers of the untwisted portion of the fibers of the paper layer 23 are easily moved, so that the crimping of the latent crimpable fibers 121 is particularly easy to be exhibited on the surface on which the high-pressure water vapor 51 is sprayed.

On the other hand, due to the side of the high pressure water jet surface side Since the fibers are strongly entangled, the fibers are not easily moved, and even if the heat of the high-pressure steam 51 is applied to the side of the high-pressure water jet surface, the crimping of the latent crimp fibers is not easily exhibited. Thus, in the face where the paper layer 23 is sprayed over the high-pressure water vapor 51, the crimping of the latent crimping fibers in the paper layer 23 is very easy to present, and on the opposite side of the surface on which the paper layer 23 is sprayed over the high-pressure water vapor 51. The surface of the high pressure water jet surface (the side of the high pressure water jet surface), the degree of curling of the latent crimping fibers in the paper layer 23 is smaller than the surface of the high pressure water vapor 51. Thereby, even if the paper layer 23 is sprayed over the surface of the high-pressure water vapor 51, the crimping of the latent crimping fibers in the paper layer 23 is very easy to present, and the paper layer 23 can be suppressed from being oriented in the width direction (CD) and/or Mechanical direction (MD) shrinks. Thereby, it is possible to suppress the size unevenness of the nonwoven fabric from becoming large.

Potentially crimped fiber sprayed on the side of the high pressure water vapor 51 The degree of curling and the degree of curling of the potentially crimpable fibers on the side of the high-pressure water jet ejection surface can be compared by comparing the number of crimped fibers and/or the crimp ratio. The number of crimps and the crimp ratio can be measured in accordance with, for example, JIS-1015 (2010)-8.1.12. When the crimping of the latent crimping fiber is large, the number of crimps and/or the crimping ratio of the crimped yarn becomes large, and when the crimping of the latent crimping fiber is small, the curling is presented. The number of crimps and/or the crimp ratio becomes smaller.

Figure 9 shows the injection of high-pressure water vapor (Figure 1 A schematic view of a cross section in the width direction of the paper layer 23 at the position of the symbol 25). In the paper layer 23, a region 54 on the surface side of the groove portion 32 formed by the high-pressure water flow is present, and a strong region of the paper layer 23 is formed, and the region 55 on the surface side of the groove portion 52 is formed by the high-pressure water vapor. The area where the strength of the paper layer 23 is slightly weaker than the above-described region 54 by the high-pressure water vapor but the paper layer 23 becomes bulky. In this manner, the paper layer 23 is formed with a strong region 54 and a weak but bulky region 55, whereby the balance between the strength and the bulk of the paper layer 23 can be obtained. In other words, it is thereby possible to form a bulky and high-strength paper layer 23.

In order to enable the unwinding of the fibers of the paper layer, the paper layer The moisture removal and the crimping of the latent crimping fibers of the paper layer are reliably carried out. As shown in Fig. 7, the nozzle holes of the steam nozzle are preferably arranged in the machine direction (MD). The method of arranging the nozzle holes of the steam nozzles in the machine direction (MD) may be provided with a plurality of nozzle holes 141A arranged in the machine direction (MD) in one steam nozzle 14A as shown in Fig. 7(a). It can also be set in the machine as shown in Figure 7(b). A method of arranging a plurality of vapor nozzles 14B in the machine direction (MD). For example, in the steam nozzles 14A, 14B shown in Figs. 7(a) and (b), among the nozzle holes 141A, 141B of the six rows arranged in the machine direction (MD), the two rows of nozzle holes from the upstream side of the step The high-pressure water vapor sprayed mainly acts on the fiber unwinding of the paper layer and the moisture removal of the paper layer. The high-pressure water vapor sprayed from the nozzle holes in the center of the two rows mainly acts on the moisture removal, from the downstream side of the step. The high-pressure water vapor sprayed by the column nozzle holes mainly acts on the crimping of the latent crimping fibers of the paper layer.

As shown in Figure 7 (a), in a vapor nozzle 14A A plurality of nozzle holes arranged in the machine direction (MD) are provided, whereby the apparatus for spraying high-pressure steam can be miniaturized. Further, as shown in Fig. 7(b), by arranging the plurality of vapor nozzles 14B in the machine direction (MD), the plurality of steam nozzles 14B can be set to a suitable high-pressure water vapor for unwinding the fibers of the paper layer. The spraying conditions, the spraying conditions for setting the appropriate high-pressure water vapor for removing the moisture of the paper layer, and the spraying conditions for setting the suitable high-pressure steam for presenting the crimping of the latent crimping fibers of the paper layer, etc. Moreover, it is very convenient to finely control the size of the groove on the surface of the paper layer, the degree of crimping of the potential crimping fiber of the paper layer, and the like.

The vapor pressure of the high pressure water vapor injected from the steam nozzle 14 It is preferably 0.2 to 1.5 MPa. When the vapor pressure of the high-pressure steam is less than 0.2 MPa, there is a case where the volume of the paper layer 23 cannot be made too large by the high-pressure steam. In addition, since the heat of the high-pressure water vapor is not deeply transmitted to the paper layer, there is a case where the crimping of the latent crimping fibers in the paper layer is less likely to occur. Further, when the vapor pressure of the high-pressure steam is more than 1.5 MPa, the paper layer 23 is perforated, the paper layer 23 is broken, and the film is sprayed.

Attracting the attraction of the vapor ejected from the vapor nozzle 14 The drum 13 is configured to attract the suction force of the paper layer 23 by the suction means built in the suction drum 13, preferably from -1 to -12 kPa. When the suction force of the suction drum 13 is less than -1 kPa, there is a case where the vapor is not completely sucked and the discharge is caused. Further, when the suction force of the suction drum 13 is larger than -12 kPa, the amount of fibers falling into the suction becomes large.

Between the front end of the vapor nozzle 14 and the upper surface of the paper layer 23 The distance is preferably 1.0 to 10 mm. When the distance between the tip end of the vapor nozzle 14 and the upper surface of the paper layer 23 is less than 1.0 mm, there is a problem that the paper layer 23 is perforated or the paper layer 23 is broken and scattered. Further, when the distance between the tip end of the vapor nozzle 14 and the upper surface of the paper layer 23 is more than 10 mm, the force of the high-pressure water vapor for forming the groove portion on the surface of the paper layer 23 is dispersed, and the energy efficiency of forming the groove portion on the surface of the paper layer 23 is obtained. The situation of deterioration.

The water content of the paper layer 23 after spraying high-pressure water vapor is preferably It is 35% or less, more preferably 30% or less. When the water content of the paper layer 23 after the high-pressure water vapor is sprayed is more than 35%, the water content of the paper layer 23 may not be 5% or less by drying by a dryer described later. In this case, it is necessary to further add drying, and there is a case where the manufacturing efficiency of the nonwoven fabric is deteriorated.

After that, as shown in Figure 1, it is transferred to the dryer 20 different dryers 22. The dryer 22 is, for example, a Yankee dryer, and the paper layer 23 is attached to a drum heated to about 160 ° C by steam to transfer the paper layer 23 Dry it. The paper layer 23 that has passed through the dryer 22 must be sufficiently dried. Specifically, the water content of the paper layer 23 after passing through the dryer 22 is preferably 5% or less. Further, when the water content of the paper layer 23 immediately after the high-pressure water vapor is sprayed is 5% or less, the paper layer 23 which has been sprayed with the high-pressure water vapor may be dried without using the dryer 22 or the like.

The dried paper layer 23 (non-woven fabric) is taken up by the winder 21.

Cut the fabricated non-woven fabric into a predetermined size as described above, Thereby, the nonwoven fabric can be used as a dry wiping paper. Further, the nonwoven fabric produced is cut into a predetermined size as described above, and the cut nonwoven fabric is impregnated with a predetermined amount of the chemical liquid, whereby the nonwoven fabric can be used as a wet wipe paper.

As mentioned above, since the non-woven fabric contains the potential for curling In the case of the crimped fiber, the step of forming the wipe from the nonwoven fabric, for example, the step of cutting the nonwoven fabric, the step of immersing the nonwoven fabric in the chemical liquid, and the like, does not cause the large volume of the nonwoven fabric to be crushed. Therefore, the wiping cloth produced from the nonwoven fabric of one embodiment of the present invention is bulky and has a good touch. Further, the groove portion formed by making the nonwoven fabric bulky is not crushed and remains after the wiping cloth is processed. Therefore, the depth of the groove can be maintained. Thereby, the wiping performance of the wiping cloth is good.

The manufacturer of the non-woven fabric of one of the above embodiments The method is modified as follows.

(1) The non-woven fabric of one of the above embodiments may also include A fiber having a fiber length of 20 mm or less which is dispersible in water (for example, fibrillated rayon fiber). Thereby, the non-woven fabric is hydrolyzable, and It is easier to discard the non-woven fabric after using the cloth.

(2) Dryer 20 before spraying high-pressure water vapor on the paper layer In the drying process, the temperature of the paper roll can also be the temperature at which the crimping of the generally crimped fiber is usually present (when the potential crimping fiber is freely movable, the crimping of the latent crimping fiber) The temperature above is expressed as the temperature. Thereby, the crimping of the latent crimping fibers existing in the high-pressure water jet ejection face portion of the paper layer can be made more difficult to occur. This is because in this case, the drying by the dryer 20 causes the stress of the contraction of the latent crimping fibers existing in the high-pressure water jet ejection face portion of the paper layer to be alleviated. Thereby, it is possible to more significantly suppress the reduction of the paper layer in the width direction (CD) and/or the machine direction (MD).

One of the embodiments and modifications may be used, or It is a combination of plurals. The variants can also be combined with one another in any way.

The above description is only one example, and the invention is not Do not limit the form of the application.

[Examples]

The invention will be explained in more detail below on the basis of examples. However, the invention is not limited by the embodiments.

In the examples and comparative examples, the water content of the paper layer before the steam is sprayed, the basis area of the paper layer, the dry thickness, the density, the dried thickness after pressing, the wet thickness, the dry tensile strength, the dry tensile ductility, and the wet stretching. The strength and wet stretch ductility were measured as described below.

(water content of the paper layer before steam spraying)

A sample piece having a size of 30 cm × 30 cm was sampled from the paper layer dried by the dryer 20, and the weight (W1) of the sample piece was measured. Thereafter, the sample piece was allowed to stand at a constant temperature of 105 ° C for 1 hour and dried, and then the weight (D1) was measured. The moisture content of the paper layer before vapor deposition is the average of the measured values of N=10.

Moisture content of paper layer before steam spraying = (W1-D1) / W1 × 100 (%)

(paper base weight)

The basis weight of the paper layer was measured by sampling a measurement sample having a size of 30 cm × 30 cm from the manufactured nonwoven fabric, and measuring the weight of the sample for measurement. The basis weight of the paper layer is the average of the measured values of N=10.

(dry thickness)

A sample for measurement of a size of 10 cm × 10 cm was sampled from the manufactured non-woven fabric. The thickness of the sample for measurement was measured using a thickness gauge (a model FS-60DS manufactured by Daiei Chemical Seiki Co., Ltd.) having a measuring instrument of 15 cm ² and measuring conditions of a load of ³ gf/cm ² . Three thicknesses were measured for one sample for measurement, and the average of three thicknesses was used as the dry thickness.

(density)

The density of the nonwoven fabric was calculated from the basis weight of the paper layer and the dry thickness.

(dry thickness after pressurization)

A sample for measurement of a size of 10 cm × 10 cm was sampled from the manufactured non-woven fabric. A 1 kg weight weight having a bottom surface of 10 cm × 10 cm was placed on the sample for measurement for 3 minutes, and the measurement sample was pressurized for 3 minutes. After removing the weight from the measurement sample, it was left for 3 minutes. Then, using a 15cm ² includes a measurement sub of a thickness gauge (Daiei Chemical Seiki Co., Ltd. Type FS-60DS), to determine the condition 3gf / cm ² Determination of the load to the pressure measured by the measuring The thickness of the sample. Three thicknesses were measured for one sample for measurement, and the average thickness of the three thicknesses was used as the dry thickness after pressurization.

(wet thickness)

A sample for measurement of a size of 10 cm × 10 cm was sampled from the manufactured non-woven fabric. The measurement sample was immersed in water (water content ratio, 400%) which was four times the mass of the measurement sample. After the determination of the impregnated water placed in the sample for 10 minutes using includes the measuring element of 15cm ² thickness gauge (Daiei Chemical Seiki Co., Ltd. Type FS-60DS), to determine 3gf / cm ² of the load measuring The conditions were measured for the thickness of the sample for measurement. Three thicknesses were measured for one sample for measurement, and the average of three thicknesses was used as the wet thickness.

(dry tensile strength)

From the non-woven fabric manufactured, the strip test piece of 25 mm width in which the longitudinal direction is the mechanical direction of the paper layer is cut, and the length direction is the width of the paper layer. A long test piece of 25 mm width was used to prepare a sample for measurement. For the measurement of the machine direction and the width direction, a tensile tester (available from Shimadzu Corporation, a tabletop precision universal tester type AGS-1kNG) equipped with a dynamometer with a maximum load capacity of 50 N was used. For the measurement samples, the tensile strength was measured under the conditions of a jig pitch of 100 mm and a tensile speed of 100 mm/min. The average value of the tensile strengths of the three measurement samples of the sample for measurement in the machine direction and the width direction was defined as the dry tensile strength in the machine direction and the width direction.

(dry stretch ductility)

From the non-woven fabric to be produced, a long test piece of 25 mm width in the machine direction of the paper layer in the longitudinal direction and a long test piece of 25 mm width in the width direction of the paper layer were cut out to prepare a sample for measurement. For the measurement of the machine direction and the width direction, a tensile tester (available from Shimadzu Corporation, a tabletop precision universal tester type AGS-1kNG) equipped with a dynamometer with a maximum load capacity of 50 N was used. For the measurement samples, the tensile ductility was measured under the conditions of a jig pitch of 100 mm and a tensile speed of 100 mm/min. Here, the tensile ductility refers to a value calculated by dividing the maximum spread (mm) when the measurement sample is pulled by the tensile tester by the jig pitch (100 mm). The average value of the tensile ductility of the three measurement samples of the sample for measurement in the machine direction and the width direction was defined as the dry stretch ductility in the machine direction and the width direction.

(wet tensile strength)

A long test piece of 25 mm width in the machine direction of the paper layer in the longitudinal direction and a long test piece of 25 mm width in the width direction of the paper layer were cut out from the manufactured non-woven fabric to prepare a sample for measurement. The measurement sample was immersed in water (water content ratio, 250%) 2.5 times the mass of the measurement sample. Then, a tensile tester (available from Shimadzu Corporation, a tabletop precision universal tester type AGS-1kNG) equipped with a dynamometer having a maximum load capacity of 50 N was used for the measurement of the machine direction and the width direction. The tensile strength was measured for the three measurement samples under the conditions of a jig pitch 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 sample for measurement in the machine direction and the width direction was defined as the wet tensile strength in the machine direction and the width direction.

(wet stretch ductility)

A long test piece of 25 mm width in the machine direction of the paper layer in the longitudinal direction and a long test piece of 25 mm width in the width direction of the paper layer were cut out from the manufactured non-woven fabric to prepare a sample for measurement. The measurement sample was immersed in water (water-containing magnification: 250%) 2.5 times the mass of the measurement sample. Then, a tensile tester (available from Shimadzu Corporation, a tabletop precision universal tester type AGS-1kNG) equipped with a dynamometer having a maximum load capacity of 50 N was used for the measurement of the machine direction and the width direction. Tensile ductility was measured for the three measurement samples under the conditions of a jig pitch of 100 mm and a tensile speed of 100 mm/min. Three measurements of the sample for the measurement of the machine direction and the width direction The average value of the tensile ductility of the fixed sample was taken as the wet stretch ductility in the machine direction and the width direction.

(better value of the measured value)

In order to allow the user to recognize the high wiping property of the non-woven fabric to be soiled, the size of the unevenness formed on the surface of the non-woven fabric is preferably a size that can be visually recognized by the user. Therefore, it is preferred that the nonwoven fabric to be produced has a dry thickness of 0.8 mm or more. Further, after the non-woven fabric is applied with pressure in a subsequent step of cutting, winding, or the like using a cutter or the like, the nonwoven fabric is preferably maintained at a thickness equal to or greater than a predetermined value. For example, in the case of a non-woven fabric having a dry thickness of 0.8 mm or more, the dry thickness after pressurization is preferably 0.6 mm or more. Further, in the case where the nonwoven fabric is immersed in the chemical liquid in order to use the nonwoven fabric as a wet wipe, in other words, the nonwoven fabric is in a wet state, the nonwoven fabric is preferably maintained at a thickness equal to or higher than a predetermined value. For example, when the nonwoven fabric has a dry thickness of 0.8 mm or more, the wet thickness is preferably 0.6 mm or more.

When the non-woven fabric is processed into a wet wipe, it will be cut off. When the woven fabric is folded by a folding machine or the like, the nonwoven fabric may be broken. In order to prevent this, the dry tensile strength of the machine direction (MD) of the nonwoven fabric is preferably 4.0 N or more, and the dry tensile strength in the width direction (CD) is preferably 3.0 N or more. Further, when a non-woven fabric is used as the wet wiping cloth, the wet tensile strength in the machine direction (MD) of the nonwoven fabric is preferably 3.0 N or more, and the wet tensile strength in the width direction (CD) is preferably 2.0 N in order to suppress cracking of the nonwoven fabric. the above.

Hereinafter, the production methods of the examples and the comparative examples were carried out. Description.

(Example 1)

The first embodiment was produced using the nonwoven fabric manufacturing apparatus 1 of one embodiment of the present invention. A papermaking raw material is prepared, which comprises: 40% by weight of conifer bleached kraft pulp (NBKP); 20% by weight of dysentery (DAIWABO RAYON Co., Ltd CORONA) having a fiber length of 1.1 dtex and a fiber length of 7 mm; Potentially crimped fiber with a fineness of 2.2 dtex and a fiber length of 5 mm and 40% by weight (made by Uniji Co., Ltd., T81 (PET/low-melting PET side-by-side type composite) Fiber (110 ° C heat setting))). The basis weight of the papermaking raw material was 50 g/m ² .

Then, the papermaking raw material was supplied to a paper layer forming belt (OS80, manufactured by Japan Hier Kang Co., Ltd.) using a raw material head, and the papermaking raw material was dehydrated using a suction box to form a paper layer. At this time, the paper layer of the paper layer had a water content of 80%. Thereafter, a high pressure water jet was used to spray the paper layer using two high pressure water jet nozzles. The high-pressure water flow energy of the high-pressure water jet sprayed on the paper layer using two high-pressure water jet nozzles was 0.2846 kW/m ² . Here, the high-pressure water flow energy is calculated by the following formula.

High-pressure water flow energy (kW/m ² ) = 1.63 × injection pressure (kg/cm ² ) × injection flow rate (m ³ /min) / treatment speed (M / min) / 60

Here, the injection flow rate (cubic M/min) = 750 × total opening area of the orifice (m ² ) × injection pressure (kg/cm ² ) 0.495

In addition, between the front end of the high pressure water jet nozzle and the top of the paper layer The distance is 10mm. Further, the nozzle hole of the high-pressure water jet nozzle has a hole diameter of 92 μm, and the nozzle hole has a hole pitch of 0.5 mm.

After the paper layer is transferred to the two paper layer conveying conveyors, Transfer to a Yankee dryer heated to 110 ° C and dry.

Next, use a steam nozzle to spray high-pressure steam On the paper layer. At this time, the vapor pressure of the high-pressure steam was 0.7 MPa, and the vapor temperature was 170 °C. In addition, the distance between the front end of the vapor nozzle and the upper surface of the paper layer was 2.0 mm. The nozzle holes of the steam nozzle are arranged in six rows in the machine direction (MD). Further, the nozzle hole of the vapor nozzle has a pore diameter of 500 μm and a hole pitch of 2.0 mm. In addition, the attraction force of the suction roller for attracting the paper layer is -1 kPa. A stainless steel 18 mesh opening sleeve is used for the outer circumference of the suction cylinder.

Then, the paper layer is transferred to the Yankee type heated to 160 ° C Dry the dryer and dry it. The dried paper layer became Example 1. The papermaking speed at the time of producing Example 1 was 70 m/min.

(Example 2)

In the second embodiment, except that the ratio of the ruthenium in the papermaking raw material is changed from 20% by weight to 55% by weight, and the ratio of the latent crimpable fiber is changed from 40% by weight to 5% by weight, the rest of the examples are the same as the examples. The manufacturing method of 1 is the same as the manufacturing method.

(Example 3)

In Example 3, except that the conifer bleached kraft pulp (NBKP) was removed from the papermaking raw material, and the ratio of the latent crimping fibers in the papermaking raw material was changed from 40% by weight to 80% by weight, the rest was the same as in Example 1. The manufacturing method is the same as the manufacturing method.

(Example 4)

In the fourth embodiment, the vapor pressure of the high-pressure steam was changed from 170 ° C to 115 ° C, whereby the vapor pressure of the high-pressure steam was changed from 0.7 MPa to 0.2 MPa, and the rest was the same as in the production method of Example 1. The method of manufacturing.

(Comparative Example 1)

Comparative Example 1 was produced by the same method as the production method of Example 1, except that the paper layer was not sprayed with high-pressure water vapor.

(Comparative Example 2)

In Comparative Example 2, the vapor pressure of the high-pressure steam was changed from 170 ° C to 110 ° C, whereby the vapor pressure of the high-pressure steam was changed from 0.7 MPa to 0.15 MPa, and the rest was the same as in the production method of Example 1. The method of manufacturing.

(Comparative Example 3)

In Example 3, in addition to the removal of the latent crimping fiber from the papermaking raw material, the ratio of the ruthenium in the papermaking raw material was changed from 20% by weight to 60% by weight. The rest were produced by the same method as the production method of Example 1.

The manufacturing conditions of the above examples and comparative examples are shown in Table 1.

The water layer of the steam sprayed in the above examples and comparative examples contains water The rate, basis weight of the paper layer, dry thickness, dry thickness after pressurization, wet thickness, dry tensile strength, dry tensile ductility, wet tensile strength and wet stretch ductility are shown in Table 2.

Each of Examples 1 to 4 has a dry thickness of 0.8 mm or more, and the dried thickness and wet thickness after pressurization are 0.6 mm or more. Further, in all of Examples 1 to 4, the ratio of the thickness after pressing to the dry thickness was 83.5% or more, and the ratio of the wet thickness to the dry thickness was 76.5% or more. From this, it is understood that all of Examples 1 to 4 are bulky, and Examples 1 to 4 still maintain a large volume even after being pressurized or in a wet state. On the other hand, the dry thicknesses of Comparative Examples 1 and 2 were all less than 0.8 mm, and Comparative Examples 1 and 2 did not become bulky. Further, in Comparative Examples 2 and 3, the dry thickness and the wet thickness after pressurization were all 0.6 mm or less, and the ratios of the thicknesses of Comparative Examples 2 and 3 to the dry thickness after pressing were 68.0% and 49.4%, respectively. The ratio of the wet thickness of the dry thickness was 68.0% and 53.0%, respectively. Therefore, it can be seen that Comparative Examples 2 and 3 have a very small volume when pressurized and in a wet state.

Comparing Example 1 with Comparative Example 3, it can be seen that by including the latent crimping fiber in the papermaking raw material, after the pressure is applied to the non-woven fabric, and the applied pressure is released, the maintenance can be maintained. High volume non-woven fabric.

Comparing Example 2 with Comparative Example 3, it can be understood that as long as at least 5% by weight of the latent crimping fiber is contained in the papermaking raw material, pressure can be applied to the nonwoven fabric, and the applied pressure is released. It is also capable of maintaining a high volume of non-woven fabric.

By comparing Example 1 with Comparative Example 1, it is understood that even if the papermaking raw material contains the latent crimping fiber, the nonwoven fabric does not bulk unless the high pressure water vapor is sprayed on the paper layer.

By comparing Example 4 with Comparative Example 2, it is known In order to produce a high-volume non-woven fabric even if pressure is applied to the non-woven fabric and the applied pressure is released, the vapor pressure of the high-pressure steam must be at least 0.2 MPa. When the vapor pressure of the high-pressure steam is less than 0.2 MPa, the fibers of the paper layer are only slightly unwound, and therefore, the latent crimping fibers can only move slightly, and as a result, it is presumed that the degree of crimping is exhibited in the latent crimping fibers. weaken.

1‧‧‧Nonwoven manufacturing equipment

11‧‧‧Material supply head

12‧‧‧High pressure water jet nozzle

13‧‧‧Attraction roller

14‧‧‧Vapor nozzle

15‧‧‧Attraction box

16‧‧‧Paper layer forming conveyor

17‧‧‧Attracting pickers

18,19‧‧‧Paper handling conveyor

20,22‧‧‧dryer

21‧‧‧Winding machine

23‧‧‧paper layer

24‧‧‧ symbol position

25‧‧‧ symbol position

Claims (10)

A method for manufacturing a non-woven fabric, comprising: a step of supplying a papermaking material having a moisture content and a latent crimping fiber to a belt body moving toward one direction, forming a paper layer on the belt body; and one side of the paper layer a step of spraying a high-pressure water jet, forming a first groove extending in the machine direction on the one surface, and drying the paper layer sprayed with the high-pressure water stream to a moisture content of 10 to 45%; Spraying high-pressure water vapor on the other side of the dried paper layer, thereby forming a second groove having a width larger than the width of the first groove and extending in the machine direction on the other surface of the paper layer, and The step of crimping the aforementioned potentially crimpable fibers of the aforementioned paper layer. The method for producing a non-woven fabric according to claim 1, wherein the ratio of the latent crimping fibers in the papermaking raw material is 5% by weight or more and 80% based on the total weight of the fibers contained in the papermaking raw material. Below weight%. The method for producing a nonwoven fabric according to the first or second aspect of the invention, wherein the vapor pressure when the high-pressure steam is sprayed onto the paper layer is 0.2 MPa or more. The method of manufacturing a non-woven fabric according to the first or second aspect of the invention, wherein the steam nozzle has a plurality of nozzle holes arranged in a machine direction. The manufacturer of the non-woven fabric as described in claim 1 or 2 of the patent application The method of forming the second groove on the other side of the paper layer and presenting the crimping of the latent crimpable fiber of the paper layer from a plurality of steam nozzles arranged in a machine direction The other side of the dried paper layer is sprayed with high-pressure water vapor. The method for producing a non-woven fabric according to claim 1 or 2, wherein the step of drying the paper layer to a moisture content of 10 to 45% is performed by heating the surface of the one surface and drying the paper layer. . The method for producing a non-woven fabric according to claim 6, wherein the step of drying the paper layer to a moisture content of 10 to 45% is to heat the surface of the one surface to a portion of the above-mentioned latent crimped fiber. The temperature at which the curl will appear. A non-woven fabric comprising a latent crimping fiber having a plurality of first grooves extending in one direction and arranged in a direction perpendicular to the one direction on one side, and having a direction extending in one direction on the other side The plurality of second groove portions having a width larger than the width of the first groove portion are present in the unidirectional vertical direction, and the crimping fibers of the surface of the second groove portion are present, and the first groove portion is present. The curling of the potentially crimped fibers on the face is large. The non-woven fabric according to claim 8, wherein the ratio of the latent crimpable fibers in the nonwoven fabric is 5% by weight or more and 80% by weight or less based on the total weight of the fibers contained in the nonwoven fabric. Non-woven fabric as described in claim 8 or 9 of the patent application, Among them, fibers having a fiber length of 20 mm or less which can be dispersed in water are contained.