JP2013151774A - Nonwoven fabric and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonwoven fabric having a pattern that is not formed by printing and kneading of pigment.SOLUTION: A nonwoven fabric 10 is produced by an air-through process. In the nonwoven fabric 10, a plurality of small fiber aggregates 30 having a color deeper than that of a texture of the nonwoven fabric 10 are arranged so as to disperse in a scattered dot-like pattern over the whole area of the nonwoven fabric 10. When a thickness of the nonwoven fabric 10, which is measured in a position at which the small fiber aggregate 30 is arranged at a pressure of 7.64 kPa is defined as T1, and a thickness of the nonwoven fabric 10, which is measured in a position at which the small fiber aggregate 30 is not arranged at the same pressure is defined as T2, a difference T3 of the thickness defined by T3=T1-T2 is 1 mm or less.

Description

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

  The air-through nonwoven fabric has a feature that the touch is softer than the nonwoven fabric manufactured by the heat embossing method because the heat-sealed portion is formed at the intersection of the fibers. In addition, when compared with other nonwoven fabrics having the same basis weight, the air-through nonwoven fabric has a greater thickness, so it has a soft touch and is still soft. Accordingly, an air-through nonwoven fabric is suitable as the nonwoven fabric used for the portion that touches the skin.

  As means for further improving the feel of the air-through nonwoven fabric, for example, it is known to use fine fibers. This is because thin fibers have a reduced rigidity, and a nonwoven fabric made from such fibers becomes soft. However, when a thin fiber is used, there is a problem that a fiber lump called a nep is easily generated when the fiber is processed by a card machine. A nep is a knot of yarn formed by intertwining fibers, and is recognized as a white lump on the nonwoven fabric when viewed macroscopically. When heat treatment is performed on the web containing the nep by the air-through method, the neps are fused to each other at a high density, resulting in a rough grain shape. This phenomenon contributes to significantly worsening the touch of the nonwoven fabric. Therefore, it is not easy to increase the touch of the nonwoven fabric by simply using thin fibers.

  Apart from the above-mentioned technology, a technology is known in which the air-through nonwoven fabric is calendered in two stages to flatten the fibers, thereby imparting a suppleness and softness to the nonwoven fabric (see Patent Document 1). However, this technique aims to increase the touch of the nonwoven fabric, and no study has been made on improving the aesthetics of the appearance of the nonwoven fabric.

  In order to impart aesthetics to the appearance of the nonwoven fabric and to cover it, there has been a demand for adding a pattern to the nonwoven fabric. Printing is easy to apply the pattern, but printing is expensive, and it is desirable to refrain from using ink from the viewpoint of safety when using the non-woven fabric on the part touching the skin. Therefore, instead of providing a pattern by printing, a pattern is formed using fibers kneaded with a pigment.

  Titanium dioxide is known as one of representative pigments. However, since titanium dioxide only colors the fibers white, it is difficult to impart a pattern even if the entire nonwoven fabric can be uniformly whitened. Moreover, when titanium dioxide is kneaded into a fiber, the spinnability of the fiber tends to deteriorate. In addition, when the fiber in which titanium dioxide is kneaded is incinerated as waste, titanium dioxide remains as a burnout, and there is a problem with respect to zero emission.

  A technique is known in which a nonwoven fabric made of fibers to which titanium dioxide is added to some extent is compressed by embossing to make the embossed part (seal part) cloudy, thereby improving the reflectance and concealability (see Patent Document 2). However, since this technique uses embossing, there is a problem that the touch of the nonwoven fabric deteriorates. In addition, the pattern formed by embossing is not easily recognized as a pattern due to its fineness and regular arrangement, and is only recognized as a whitish non-woven fabric as a whole.

JP 2006-233365 A Japanese Patent Laid-Open No. 7-292551

  As a result of diligent research on the technology for applying a pattern to a nonwoven fabric without performing printing or mixing of pigments, the present inventors have made active use of NEP that has been avoided so far, It has been found that an unprecedented pattern can be imparted to the nonwoven fabric without impairing the good touch it has.

The present invention has been made based on the above knowledge, and is a nonwoven fabric produced by an air-through method,
In the non-woven fabric, a plurality of small fiber masses that are darker than the formation of the non-woven fabric are dispersed and arranged in a scattered manner over the entire area of the non-woven fabric,
The thickness of the nonwoven fabric measured under 7.64 kPa at the position where the fibril mass is arranged is T1, and the thickness of the nonwoven fabric measured under the same pressure at the position where the fibril mass is not arranged is T2. In this case, a nonwoven fabric having a thickness difference T3 defined by T3 = T1-T2 of 1 mm or less is provided.

Moreover, the present invention uses a short fiber as a raw material, forms a web by a card method, and then blows hot air to the web by an air-through method to fuse the intersections of the fibers,
After the fibers are fused to obtain an air-through nonwoven fabric, a pair of smooth rolls are used, and the linear pressure between the rolls is set to 100 N / cm or more and 1500 N / cm or less, and the air-through nonwoven fabric is subjected to calendering. The present invention provides a method for producing a nonwoven fabric that reduces the difference in thickness between a position where a small fiber lump is disposed and a position where the small fiber lump is not disposed.

  ADVANTAGE OF THE INVENTION According to this invention, the nonwoven fabric which has a pattern which does not depend on printing and the kneading of a pigment is provided, without impairing the favorable touch which an air through nonwoven fabric originally has. Moreover, according to this invention, the nonwoven fabric which has such a pattern can be easily manufactured using the edge cut of the nonwoven fabric conventionally discarded.

FIG. 1 is a plan view showing an embodiment of the nonwoven fabric of the present invention. FIG. 2 is a schematic view showing an apparatus suitably used for producing the nonwoven fabric shown in FIG. FIG. 3 is a plan view showing an embodiment of the nonwoven fabric of the present invention. FIG. 4 is a diagram illustrating a main part of the card machine in the nonwoven fabric manufacturing apparatus used in the examples.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The top view of one Embodiment of the nonwoven fabric based on this invention is shown by FIG. The nonwoven fabric 10 shown in the figure is manufactured by the air-through method. The air-through method is a method in which hot air is blown to a fiber web containing heat-fusible fibers produced by various web production methods to fuse the intersections of the heat-fusible fibers in the web. A method of forming a nonwoven fabric. As shown in the figure, in the non-woven fabric 10, the deeply formed portions 20 and the thinly formed portions 21 are alternately extended in stripes with irregular widths and lengths. The direction in which the deep portion 20 and the thin portion 21 extend generally coincides with the flow direction (MD) when the nonwoven fabric 10 is manufactured. In the present specification, the term “geometry” refers to the distribution of constituent fibers and the color tone on the appearance resulting from the distribution among the quality of the nonwoven fabric. In general, the nonwoven fabric 10 is often white due to the material of the constituent fibers and the like, but the portion 20 having a deep formation looks relatively dark white. On the other hand, the part 21 with a thin formation looks relatively light white.

  The deep part 20 and the thin part 21 of the formation do not need to extend over the entire length of the nonwoven fabric, and may be intermittent. In the case of being intermittent, the extension length of the dark portion 20 and the extension length of the thin portion 21 may be the same or different. Further, the deep portion 20 and the thin portion 21 need not have a constant width along the extending direction. Rather, it is preferable that the width changes irregularly because the visual aesthetics become remarkable. The width of the dark portion 20 and the width of the thin portion 21 may be the same or different.

  The site | part 20 with a deep formation and the site | part 21 with a thin formation are generally produced by the basis weight difference of the nonwoven fabric resulting from the distribution state of a constituent fiber. Specifically, the dense part 20 has a higher density of constituent fibers than the thin part 21, and as a result, the basis weight is relatively high. On the contrary, the portion 21 with a low formation has a lower distribution density of the constituent fibers than the portion 20 with a high formation, and as a result, the basis weight is relatively low. It is not necessary for the dense portions 20 that exist in the nonwoven fabric 10 to have the same basis weight. Similarly, a plurality of thin portions 21 in the nonwoven fabric 10 need not have the same basis weight.

  The portion 20 with a deep formation has a relatively higher basis weight than the portion 21 with a thin formation. There is no difference as much as the amount. The ratio of the thickness of the dark part 20 and the thin part 21 (thickness of the dark part 20 / thick part 21) is the thin part 20 and the thin part. The ratio is smaller than the ratio of the basis weight to the part 21 (basis weight of the part 20 having a deep formation / basis weight of the part 21 having a low formation), specifically, ½ or less. As a result of the ratio of the thickness of the dense part 20 and the thin part 21 being not as different as the basis weight ratio of the dense part 20 and the thin part 21, the dense part The light transmittance of 20 is relatively lower than that of the thin portion 21. Due to this, the dark portion 20 appears to be relatively whiter than the light portion 21.

  In addition to the deep portion 20 and the thin portion 21, the nonwoven fabric 10 is provided with a plurality of small fiber masses 30 that are darker than the formation of the nonwoven fabric 10. The small fiber mass 30 has an irregular shape, and its outline and size are various. Further, the small fiber masses 30 are irregularly distributed in a scattered manner over the entire area of the nonwoven fabric 10. There is no particular relationship between the arrangement position of the small fiber mass 30 and the formation position of the above-described dark portion 20 and the thin portion 21. For example, the fibril mass 30 can be located on the dark portion 20. It can also be located on the thin part 21 of the formation. Or it can also be located so that the site | part 20 with a deep formation and the site | part 21 with a thin formation may be straddled. Since the fibril mass 30 is in such a shape, size, and arrangement, the fibril mass 30 exhibits a cloud-like pattern scattered on the ground of the nonwoven fabric 10, and thereby the nonwoven fabric. No. 10 has the appearance of a cloud paper that is a kind of Japanese paper.

  The small fiber lump 30 is configured from a dense aggregate of the constituent fibers of the nonwoven fabric 10. In the small fiber lump 30, the basis weight is higher than the other parts of the nonwoven fabric 10. As a result, the small fiber lump 30 has a lower light transmittance than other portions of the nonwoven fabric 10, and as a result, the fibril mass 30 has a darker color than the formation of the nonwoven fabric 10. As described above, since the nonwoven fabric 10 is generally white, the small fiber mass 30 has a darker white color than other parts of the nonwoven fabric 10. Depending on the raw material of the nonwoven fabric 10, the small fiber mass 30 may have a higher degree of fusion at the intersection of the constituent fibers than the other portions of the nonwoven fabric 10. By increasing the degree of fusion, the dark color (the dark white degree) of the fibril mass 30 is further increased.

  From the viewpoint of further increasing the dark color (dark white degree) of the small fiber mass 30, the fibers constituting the small fiber mass 30 have fine irregularities such as fine wrinkles and / or fine cracks on the surface thereof. It is preferable. The constituent fiber of a general nonwoven fabric is made of a synthetic resin having fiber forming ability, and the surface of such a fiber is usually smooth, but by forming fine irregularities on the surface of the fiber, light is emitted to the irregularities. Due to irregular reflection, the dark color of the small fiber mass 30 becomes more prominent. The formation of irregularities on the fiber surface can be confirmed by electron microscope observation of the fiber surface. Moreover, in order to form an unevenness | corrugation on the surface of a fiber, what is necessary is just to perform the calendar process employ | adopted, for example in the manufacturing method of the nonwoven fabric 10 mentioned later.

  The size of the small fiber mass 30 when the nonwoven fabric 10 is viewed in plan varies. However, since the presence of an excessively large fibril mass 30 may not lead to an improvement in the appearance of the nonwoven fabric, the size of the fibril mass 30 should be within a certain range. Is preferred. From this viewpoint, for example, the equivalent circle diameter of the small fiber mass 30 by image analysis of the nonwoven fabric 10 in a plan view is preferably 0.5 mm or more and 30 mm or less, more preferably 1 mm or more and 15 mm or less, and the standard deviation at that time Is preferably 1 mm or more and 30 mm or less, and more preferably 4 mm or more and 15 mm or less.

  On average, the fibril lump 30 is at least 1, preferably 1 to 600, more preferably 10 to 300, and still more preferably 32 to 100 in a 10 cm square region of the nonwoven fabric 10. The following arrangement is preferable from the viewpoint of improving the aesthetic appearance due to the small fiber mass 30.

Since the small fiber mass 30 is dark white, the nonwoven fabric 10 has a high reflectance per unit basis weight. As a result, the nonwoven fabric 10 has high concealability. The reflectance per unit basis weight (g / m ² = gsm) of the nonwoven fabric 10 is preferably 1.2% / gsm or more, more preferably 1.4% / gsm to 5.0% / gsm. More preferably, it is 1.8% / gsm or more and 2.5% / gsm or less. The reflectance per unit basis weight is measured under the following measurement conditions using, for example, a color difference meter NF333 manufactured by Nippon Denshoku Industries Co., Ltd., and the reflectance calculated from the following formula is calculated based on the basis weight (g / M ² ).
Measurement part diameter: φ30 mm (in accordance with this, the internal lens is for φ30 mm)
Number of times: 10 times Wavelength: 500 nm
Calculation formula: reflectance (%) = [(r−r ₀ ) / (100−r ₀ )] × 100
(Where, r: value of nonwoven fabric, r ₀ : value of red reference plate)
The red reference plate was manufactured by Nippon Denshoku Industries Co., Ltd., and the color defined by (X26.86, Y16.85, Z5.34) was used.

  As described above, the nonwoven fabric 10 has the deep portion 20 and the thin portion 21 and the small fiber masses 30 are arranged in the form of scattered dots. Express the pattern. Moreover, since the nonwoven fabric 10 is manufactured by an air-through method, it is bulky, flexible, and has a good touch. Therefore, the nonwoven fabric 10 is particularly useful as a material constituting the outermost surface of various articles. For example, it is suitably used as a layer constituting the outermost surface of a disposable wearing article such as a disposable diaper or a disposable medical garment.

Although it depends on the specific use of the nonwoven fabric 10, the basis weight of the nonwoven fabric 10 is generally 6 g / m ² or more and 100 g / m ² or less, particularly preferably 15 g / m ² or more and 30 g / m ² or less.

  In relation to the thickness of the nonwoven fabric 10, the nonwoven fabric 10 was measured under a pressure of 7.64 kPa at the position where the small fiber mass 30 was arranged (the tip of the probe is a disk and the diameter is 5 mm). When the thickness of the nonwoven fabric 10 measured under the same pressure at a position where the fibril lump 30 is not disposed 10 is T2, the thickness difference T3 defined by T3 = T1−T2 is T3. 1 mm or less. That is, the thickness difference between the position where the small fiber mass 30 is arranged and the other positions is small. As described above, since the small fiber mass 30 is a mass in which the constituent fibers of the non-woven fabric 10 are densely gathered, there is a tendency to exhibit a hard feel, so that the difference between the thickness T2 and the thickness T1 is reduced. Thus, when the surface of the nonwoven fabric 10 is touched, the hardness due to the small fiber mass 30 is hardly perceived. As a result, the touch of the nonwoven fabric 10 is improved. From the viewpoint of making this effect more remarkable, T3 is 0 mm or more, preferably 0.1 mm or less, and more preferably 0.05 mm or less.

  The thicknesses T1 and T2 of the nonwoven fabric 10 are measured using, for example, a dial gauge thickness gauge (JIS B 7503 (1997), UPRIIGHT DIAL GAUGE, No. 25, measuring element 5 mmφ flat type manufactured by PEACOCK) under the above-described pressure. Is done. The measurement is performed at 10 points or more for each of T1 and T2. Then, the arithmetic average value of T1 and the arithmetic average value of T2 are calculated, and the difference between them is T3.

  Examples of the constituent fibers of the nonwoven fabric 10 include heat-fusible fibers. Examples of the heat-fusible fiber include a bicomponent composite fiber composed of a low-melting point resin and a high-melting point resin, and the low-melting point resin forms a part in the fiber length direction. Specific examples include core-sheath type composite fibers and side-by-side type composite fibers. Although the thickness of these fibers depends on the specific use of the nonwoven fabric 10, it is preferably 0.5 dtex or more and 8 dtex or less, particularly preferably 0.5 dtex or more and 3.0 dtex or less. In particular, by using fine fibers, the small fiber mass 30 can be successfully formed. Specifically, it is preferable to use a thin fiber of 0.5 dtex or more and 2.5 dtex or less, more preferably a thin fiber of 0.5 dtex or more and 1.5 dtex or less, and a thin fiber of 0.8 dtex or more and 1.2 dtex or less. More preferably, fibers are used.

  Examples of the combination of the low melting point resin and the high melting point resin constituting the bicomponent composite fiber include polyethylene terephthalate (PET) / polyethylene (PE), polypropylene (PP) / polyethylene (PE), and the like.

  The nonwoven fabric 10 may contain only the heat-fusible fiber described above, or may contain fibers other than the fiber in addition to the heat-fusible fiber. Examples of such fibers include fibers having no heat fusibility such as cotton and rayon. When the nonwoven fabric 10 contains fibers other than the heat-fusible fibers, the proportion of the fibers in the nonwoven fabric 10 is preferably 50% by mass or less.

  A white pigment is kneaded into the constituent fibers of the nonwoven fabric 10 to increase the whiteness of the nonwoven fabric 10, resulting in a pattern caused by the small fiber mass 30, a dark portion 20 and a thin portion 21. The pattern may be more prominent. For this purpose, for example, titanium oxide can be used as a white pigment. The white pigment is preferably contained in an amount of 0.1% by mass or more and 5.0% by mass or less, more preferably 1.5% by mass or more and 4.0% by mass or less based on the mass of the entire fiber.

  When the nonwoven fabric 10 is produced by a method using a card machine, which will be described later, it is preferable to use short fibers having a fiber length of 20 mm to 75 mm, particularly 45 mm to 75 mm as the constituent fibers.

  The nonwoven fabric 10 is basically composed of a single layer of nonwoven fabric obtained by the air-through method. However, the nonwoven fabric 10 includes other nonwoven fabrics and films as long as the appearance pattern of the nonwoven fabric 10 is not impaired. You may be in the state laminated | stacked with the other sheet material.

  Next, the suitable manufacturing method of the nonwoven fabric 10 is demonstrated, referring FIG. FIG. 2 shows an apparatus 100 suitably used for manufacturing the nonwoven fabric 10. The apparatus 100 includes a raw cotton opening part 110, a web forming part 120, a hot air blowing part 130, and a calendering part 140 from the upstream side toward the downstream side.

  The raw cotton opening part 110 is an opener 111 that opens the fibers that are the raw material of the nonwoven fabric 10 and an endless belt that conveys the fiber opening 11 of the fibers opened by the opening machine 111 to the web forming part 120. A conveyance belt 112 is provided.

  The web forming unit 120 includes a card machine. As the card machine, for example, a parallel card machine, a semi-random card machine, a random card machine, or a parallel card machine in which a cross layer and a drafter are combined is used. In particular, it is preferable to use a parallel card machine that is a card machine that can easily form the dark portion 20 and the thin portion 21.

  The card machine has a feed roller 121, a take-in roller 122, a pre-cylinder 123, a transformer roller 124, a main cylinder 127 having a plurality of workers 125 and a stripper 126 arranged on the peripheral surface, a doffer 128 and a condenser roller 129 in this order. Configured. The rotation direction of each roller is the direction shown by the arrow in FIG. The opened body 11 transported by the transport belt 112 is carded while being transferred by each roller in the card machine to form the web 12 and is taken out on the take-up conveyor 131.

  The feed roller 121 and the take-in roller 122 are rollers that supply the spread body 11 transported by the transport belt 112 to the pre-cylinder 123. The pre-cylinder 123 is a roller that preliminarily opens the opened body 11 before supplying the opened body 11 to the main cylinder 127. A stripper 150 and a worker 151 are disposed on the circumferential surface of the pre-cylinder 123. One stripper 150 and one worker 151 form one set, and a plurality of sets of strippers 150 and workers 151 are arranged. The transformer roller 124 is a roller that adjusts the supply amount of the spread body 11 to the main cylinder 127 according to the rotation speed.

  The main cylinder 127 and a plurality of pairs of workers 125 and strippers 126 on the peripheral surface thereof are transferred to the worker 125 of the opened body 11 supplied to the main cylinder 127 and the opened body 11 transferred to the worker 125. This is the part where the spread body 11 is opened by repeating the return to the main cylinder 127 by the stripper 126.

  The doffer 128 receives the web on the main cylinder 127 that rotates at a high speed at a low speed, thereby increasing the weight of the web. The condenser roller 38 rotates at a lower speed than the doffer 37, receives the web on the doffer 37, adjusts the shape of the web, and adjusts the delivery of the web to the transfer speed of the take-up conveyor 39. The doffer 37 and the condenser roller 38 randomize the fiber arrangement by repeating the delivery of the web.

  The hot air blowing unit 130 includes a hood 132 and a conveyor belt 133 made of a breathable net that circulates in the hood 132. Inside the hood 132, hot air is blown toward the conveyor belt 133 in the direction of the arrow in FIG. The conveyor belt 133 is made of a resin such as metal or polyethylene terephthalate. Further, the hot air blowing unit 130 includes a transport belt 134 that is an endless belt that transports the web 12 taken out on the take-up conveyor 131 into the hood 132.

  The calendar processing unit 140 includes a pair of calendar rollers 141 and 142 whose peripheral surfaces are smooth. The calendar rollers 141 and 142 are made of, for example, metal, rubber, paper, or the like. The calendar rollers 141 and 142 may be made of the same material or different materials. Of the calendar rollers 141 and 142, one of them is preferably made of metal and the other is made of paper.

  A preferred method of manufacturing the nonwoven fabric 10 using the manufacturing apparatus 100 having such a configuration will be described with reference to FIG. First, in the raw cotton opening section 110, raw fibers are put into the opening machine 111, the opened fiber body 11 is manufactured, and the opened body 11 is transported to the web forming section 120 using the transport belt 112.

  As the raw material fibers, for example, short fibers of heat-fusible fibers made of bicomponent composite fibers are used. Furthermore, it is also preferable to use a short fiber obtained by subjecting a non-woven fabric to a defibrating treatment as a part of the raw short fiber. The cut end of the nonwoven fabric refers to a portion generated by cutting, with a slitter, an unfavorable formation that occurs in the left and right side regions in the flow direction during production of the nonwoven fabric. Such cuts are usually discarded, but in the present invention, the above-described small fiber mass 30 is efficiently generated in the nonwoven fabric 10 by reusing it. The cut end of the nonwoven fabric may be produced in the production process of the nonwoven fabric of the present invention, or may be produced in the production process of another type of nonwoven fabric. From the standpoint that the types of raw materials are the same, it is preferable to use cuts generated in the process of manufacturing the nonwoven fabric of the present invention. As will be described later, it is not essential to use a cut end of the nonwoven fabric as the raw fiber, and a small fiber mass can be produced in the nonwoven fabric without using the end cut.

  In this manufacturing method, Preferably, what cut | disconnected the above-mentioned non-woven fabric to the defibrating process and returned to the short fiber again is used as a part of the raw fiber. Short fibers are regenerated by subjecting the end of the nonwoven fabric to defibration treatment, but it is not easy to reliably perform defibration. Some bonds (fusion, etc.) remain. By using the short fibers in such a state as a part of the raw fibers, the small fiber mass 30 is successfully formed in the manufacturing process of the nonwoven fabric 10, specifically, in the web forming unit 120. Moreover, it becomes easy to form the site | part 20 with a deep formation and the site | part 21 with a thin formation in the nonwoven fabric 10 by using the short fiber reproduced | regenerated from the cut end as a part of raw material fiber. For example, a defibrator can be used for defibrating the cut ends. As such a defibrating machine, the same ones conventionally used in the technical field can be used. For example, a device having a feed roll for supplying a piece of nonwoven fabric and a garnet cylinder around which a saw-like wire is wound and further provided with a blower mechanism can be used as a defibrating machine.

  From the viewpoint of successfully forming the small fiber mass 30, the ratio of the short fibers regenerated from the cut ends to the raw fiber is preferably 1% by mass or more and 40% by mass or less, particularly preferably 3% by mass or more and 30% by mass or less. .

  From the viewpoint of successfully forming the small fiber mass 30, it is also advantageous to use a fiber having a small fiber diameter as the raw fiber as described above. Specifically, as described above, it is preferable to use fine fibers of 0.5 dtex or more and 2.5 dtex or less, and it is more preferable to use fibers of 0.5 dtex or more and 1.5 dtex or less.

  In order to adjust the number and size of the small fiber masses 30 formed on the web 12, the ratio of the regenerated fibers from the end cut, the adjustment of the worker speed of the card machine, the rotation speed of the main cylinder, etc. may be controlled.

  The spread body 11 obtained by opening the raw fibers in the raw cotton opening section 110 is transported to the web forming section 120 by the transport belt 22 to form the web 12. Specifically, the spread body 11 is supplied to the pre-cylinder 123 via the feed roller 121 and the take-in roller 122 and pre-opened. The pre-opened opened body 11 is peeled off from the pre-cylinder 123 by the transformer roller 124 and supplied to the main cylinder 127. And with respect to the spread body 11 supplied on the main cylinder 127, using the plurality of workers (four pairs in FIG. 2) 125 and the stripper 126, the operation of moving the spread body 11 to the worker 125, By repeating the operation of returning the spread body 11 transferred to the worker 125 to the main cylinder 127 by the stripper 126, a web is formed. As in the apparatus 100 shown in FIG. 2, it is preferable to use an apparatus having two opening cylinders of a main cylinder 127 (for example, φ950 mm) and a pre-cylinder 123 (for example, φ500 mm).

  The operating condition of the card machine in this manufacturing method is characterized in that the peripheral speed S2 of the worker 125 is very slow with respect to the peripheral speed S1 of the main cylinder 127. That is, the characteristic is that the value of S1 / S2 is smaller than the conventional operating condition of the card machine. Specifically, the value of S1 / S2 is preferably set to 2/1000 or more and 80/1000 or less, more preferably 5/1000 or more and 50/1000 or less. By adopting such operating conditions, the small fiber mass 30 can be successfully formed in the web 12 without using a non-woven fabric end cut as the raw fiber. When the non-woven fabric end cut is used as the raw fiber, the small fiber mass 30 can be formed more successfully by adopting this operating condition. Furthermore, by adopting this operating condition, it becomes easy to form the portion 20 having a deep formation and the portion 21 having a low formation in the web 12. When this operating condition is adopted and the end of the nonwoven fabric is not used as the raw material fiber, as shown in FIG. 3, the darkness of the formation is substantially uniform, and the small fiber mass 30 is scattered throughout the entire area. It becomes easy to obtain the nonwoven fabric 10 that is irregularly distributed. Similarly to the nonwoven fabric shown in FIG. 1, the nonwoven fabric 10 shown in FIG.

  When employing the above operating conditions, the peripheral speed of the worker 125 itself is preferably 70 m / min or less, more preferably 50 m / min or less, and even more preferably 30 m / min.

  In addition, the operating condition of the card machine in this manufacturing method is also characterized in that the clearance between the pre-cylinder 123 and the worker 151 is small. Specifically, among the plurality of workers 151 arranged in the pre-cylinder 123, the clearance between the worker located on the most upstream side and the pre-cylinder 123 is preferably 0.1 mm or more, particularly preferably 0.3 mm or more. 1.0 mm or less, particularly 0.8 mm or less, more preferably 0.5 mm or less. The clearance between the plurality of workers 151 arranged in the pre-cylinder 123 and the pre-cylinder 123 is set so as to become narrower in order from the worker 151 arranged on the upstream side to the worker 151 arranged on the downstream side. It is normal. However, if the clearance between the worker 151 located on the most upstream side and the pre-cylinder 123 is set to be narrower than the clearance between the worker 151 located on the immediate downstream side and the pre-cylinder 123, the end of the nonwoven fabric is not used as the raw fiber. However, the small fiber mass 30 can be successfully formed in the web 12. When the non-woven fabric end cut is used as the raw fiber, the small fiber mass 30 can be formed more successfully by adopting this operating condition. Furthermore, by adopting this operating condition, it becomes easy to form the portion 20 having a deep formation and the portion 21 having a low formation in the web 12.

  In this way, a web 12 is obtained in which a dark portion and a thin portion are formed along the flow direction (MD), and randomly arranged fibrils are formed. The web 12 is conveyed to the hot air blowing unit 130. Hot air heated to a predetermined temperature is applied to the upper surface of the web 12 conveyed into the hood 132 of the hot air blowing unit 130, that is, the surface opposite to the surface facing the conveyor belt 133. Sprayed through. That is, air through processing is performed. Heat is applied to the web 12 by blowing hot air, and the intersections of the fibers are fused.

  The temperature and wind speed of the hot air blown onto the web 12 are appropriately selected according to the melting point of the constituent resin of the heat-fusible fiber and the basis weight of the web 12. When the fusion resin is polyethylene, for example, the temperature of the hot air is preferably set to about 125 ° C. to 145 ° C., and the wind speed is preferably set to about 0.5 m / s to 3 m / s.

  The preliminary nonwoven fabric 13 is obtained by being subjected to the treatment by the hot air blowing unit 130. The preliminary nonwoven fabric 13 is an air-through nonwoven fabric. In the preliminary nonwoven fabric 13, the portion where the small fiber lump is disposed has a harder feel than the other portions of the preliminary nonwoven fabric 13 due to the denseness of the fibers and the close fusion between the fibers. Further, the contrast between the dark part and the thin part is not sufficiently clear. Therefore, for the purpose of reducing the hardness of the portion where the small fiber mass is arranged and sufficiently clarifying the contrast between the dark portion and the thin portion, the preliminary nonwoven fabric 13 in the calendering section 140 is used. To calendar processing. In the calendering process, an external force is applied to the fibers constituting the small fiber lump to cause fine cracks called fine wrinkles and hair cracks on the surface of the fiber, and the degree of irregular reflection of the small fiber lump is reduced. There is also an aim to increase.

  The calender rollers 141 and 142 used for calendering may be used without being heated, or may be used in a heated state. From the viewpoint of reducing the hardness of the portion where the small fiber mass is disposed, it is preferable to use the calendar rollers 141 and 142 without heating. In this case, the surface temperature of the calendar rollers 141 and 142 is room temperature or is slightly higher than room temperature due to friction.

  The linear pressure applied to the preliminary nonwoven fabric 13 sandwiched between the calendar rollers 141 and 142 is preferably 100 N / cm or more, particularly 300 N / cm or more, more preferably 700 N / cm or more, preferably 1500 N / cm or less, particularly 1300 N / cm. Hereinafter, it is preferable that it is 1000 N / cm or less from the point which can reduce the hardness of the site | part in which the small fiber lump is arrange | positioned effectively. Moreover, it is preferable from the point that the contrast of the site | part with a deep formation and the site | part with a thin formation can fully be clarified.

The calendar rollers 141 and 142 can perform processing with the peripheral speed set to be the same. Alternatively, a speed difference may be provided for the peripheral speed. By providing the speed difference, it is possible to effectively reduce the hardness of the portion where the small fiber mass is arranged. When the speed difference, the peripheral speed of the calendar roller of the slower of the peripheral speed of v _1, the peripheral speed of the calendar roller of faster peripheral speeds were and _{v 2, (v 2 -v 1} ) / v 1 It is preferable to set the value of x100 (calendar roll speed ratio) to 0.1% or more, particularly 0.1% to 3%, particularly 0.5% to 2%. When providing the speed difference when the materials of the calendar rollers 141 and 142 are the same, the circumferential speed of either calendar roller may be increased. When the material is different, for example, when one calendar roller is made of metal and the other calendar roller is made of paper, and the material (nonwoven fabric) is wound around a paper calendar roll, the metal calendar Increasing the peripheral speed of the roller is preferable from the viewpoint of ensuring the conveyance stability.

  The target nonwoven fabric 10 is obtained by subjecting the preliminary nonwoven fabric 13 to calendering. The non-woven fabric 10 thus obtained has stripe portions 20 having a deep texture and thin portions 21 having an irregular width and length alternately along the flow direction (MD) in the manufacturing process. It will extend in the shape. Further, the plurality of small fiber masses 30 having an irregular shape that is darker than the formation of the nonwoven fabric 10 are irregularly distributed in a scattered manner over the entire area of the nonwoven fabric 10. Thus, according to this manufacturing method, the nonwoven fabric which has a pattern which does not depend on printing and the kneading of a pigment can be easily manufactured, without impairing the favorable touch which an air through nonwoven fabric has inherently. In addition, since it is possible to utilize the cut end of the nonwoven fabric that has been treated as waste, the environmental load can be reduced and it is economical.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the calendering process in the method for manufacturing the nonwoven fabric 10, one-stage calendering is performed, but two or more calendering processes may be performed as necessary.

  In addition, as described above, in the present invention, as shown in FIG. 1, the dark portion and the thin portion of the formation are alternately extended in stripes with irregular widths and lengths, And a nonwoven fabric in which a plurality of small fiber masses having an irregular shape that is darker than the ground are irregularly distributed in a scattered manner over the entire area of the nonwoven fabric, and a ground as shown in FIG. A non-woven fabric in which a plurality of irregularly shaped small fiber masses having a substantially uniform density and a darker color than the ground are irregularly distributed in a scattered manner over the entire area of the non-woven fabric And both.

  Further, regarding the doffer 128 in the nonwoven fabric manufacturing apparatus 100 shown in FIG. 2, the doffer 128 is preferably a single doffer as shown in the figure, but a double doffer type apparatus is also preferably used. Further, the number of card machines used for manufacturing the web is one in FIG. 2, but a plurality of card machines, for example, two or three card machines may be used.

This invention discloses the manufacturing method of the following nonwoven fabrics and nonwoven fabrics further regarding embodiment mentioned above.
<1> A nonwoven fabric produced by an air-through method,
In the non-woven fabric, a plurality of small fiber masses that are darker than the formation of the non-woven fabric are dispersed and arranged in a scattered manner over the entire area of the non-woven fabric,
The thickness of the nonwoven fabric measured under a pressure of 7.64 kPa at the position where the fibril mass is arranged is T1, and the thickness of the nonwoven fabric measured under the same pressure at the position where the fibril mass is not arranged. A nonwoven fabric having a thickness difference T3 defined by T3 = T1-T2 of 1 mm or less when T2.

<2> The nonwoven fabric according to <1>, wherein at least one of the small fiber masses is disposed in an area of 10 cm square on average.
<3> The nonwoven fabric according to <2>, wherein the fibril mass is averagely arranged in the range of 1 to 600 in a 10 cm square area.
<4> The nonwoven fabric according to <3>, wherein the fibril mass is averagely arranged in the range of 2 to 100 in a 10 cm square area.
<5> The nonwoven fabric according to any one of <1> to <4>, wherein the basis weight is higher than that of other portions of the nonwoven fabric.
<6> The nonwoven fabric according to any one of <1> to <5>, wherein a circle-equivalent diameter of the small fiber mass by image analysis of the nonwoven fabric in a plan view is 0.5 mm or more and 30 mm or less.

<7> The non-woven fabric according to any one of <1> to <6>, wherein in the non-woven fabric, a dark portion and a thin portion are alternately extended in a stripe shape.
<8> The basis weight is relatively higher in the part where the formation is darker than the part where the formation is thin, and the ratio of the thickness between the part where the formation is thin and the part where the formation is thin is The nonwoven fabric according to any one of <1> to <7>, wherein the nonwoven fabric is smaller than a basis weight ratio between a dark portion and a thin portion.
<9> The fiber according to any one of <1> to <8>, wherein the fiber constituting the fibril mass has fine irregularities such as fine wrinkles and / or fine cracks on a surface thereof. Non-woven fabric.
<10> The nonwoven fabric according to any one of <1> to <9>, wherein the reflectance per basis weight is 1.4% / gsm or more and 5.0% / gsm or less.
<11> The nonwoven fabric according to any one of <1> to <10>, wherein a white pigment is kneaded into the constituent fibers.

<12> An absorbent article using the nonwoven fabric according to any one of <1> to <11> as a member.
<13> The absorbent article according to <12>, wherein the nonwoven fabric is used as an exterior material.
<14> The absorbent article according to <13>, which is a disposable diaper.
<15> In a method for producing a nonwoven fabric having a step of using short fibers as raw materials, forming a web by a card method, and then blowing hot air to the web by an air-through method to fuse the intersections of the fibers,
After the fibers are fused to obtain an air-through nonwoven fabric, a pair of smooth rolls are used, and the linear pressure between the rolls is set to 100 N / cm or more and 1500 N / cm or less, and the air-through nonwoven fabric is subjected to calendering. The nonwoven fabric manufacturing method <16> for reducing the difference in thickness between the position where the small fiber lump is disposed and the position where the small fiber lump is not disposed. Preferably, the linear pressure between the rolls is 100 N / cm or more. In particular, the production method according to the above <15>, which is set to 300 N / cm or more, more preferably 700 N / cm or more, and 1500 N / cm or less, particularly 1300 N / cm or less, and further 1000 N / cm or less.

<17> The manufacturing method according to <15> or <16>, wherein the web is formed by setting a speed of a worker in a card machine used for forming the web to 30 m / min or less.
<18> In a method for producing a nonwoven fabric, comprising using short fibers as raw materials, forming a web by a card method, and then blowing hot air to the web by an air-through method to fuse the intersections of the fibers.
The speed of the worker in the card machine is set to 30 m / min or less to form a web,
After the air-through nonwoven fabric is obtained by fusing the fibers together, the air-through nonwoven fabric is subjected to calendering at a position where the small fiber mass is arranged and a position where the small fiber mass is not arranged. A method for producing a nonwoven fabric that reduces the difference in thickness.
<19> Any one of the above <15> to <18>, wherein a clearance between the worker located at the most upstream side among the workers arranged in the pre-cylinder and the pre-cylinder is 0.1 mm to 1.0 mm. The manufacturing method as described in.
<20> Among the workers arranged in the pre-cylinder, the clearance between the worker located most upstream and the pre-cylinder is set to be narrower than the clearance between the worker located immediately downstream and the pre-cylinder < 15. The production method according to any one of <15> to <19>.
<21> Using a short fiber obtained by subjecting a non-woven fabric end piece to defibration treatment as a part of the short fiber as a raw material, a plurality of irregularly shaped small pieces are formed during the formation of the web. The production method according to any one of <15> to <20>, wherein the fiber mass is irregularly distributed in a scattered manner over the entire area of the web.

<22> Any one of the above <15> to <21>, wherein the short fiber is preferably 0.5 dtex or more and 2.5 dtex or less, more preferably 0.5 dtex or more and 1.5 dtex or less. 2. The production method according to claim 1.
<23> Perform the calendar processing using a pair of smooth rolls,
The production method according to any one of <15> to <22>, wherein a speed difference of 0.1% or more is set between the rolls.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, “%” means “mass%”.

[Example 1]
As the first raw fiber, a concentric core-sheath type composite fiber having a core made of PET and a sheath made of PE was used. This fiber had a length of 51 mm and contained 0.5% titanium oxide as a white pigment. Moreover, the thickness of this fiber was as shown in Table 1.

  In addition to the first raw fiber, a core-sheath type composite fiber regenerated by defibration of the cut end of the nonwoven fabric produced in this example was used as the second raw fiber. For the defibration, a machine called a defibrator, which has a feed roll for supplying a piece of nonwoven fabric, a pre-cylinder around which a saw-shaped wire is wound, and a blower mechanism (not shown) was used. . In the regenerated core-sheath type composite fiber, it was observed that some of the fiber bonds remained. The ratio of the 2nd raw material fiber was made into the value shown in Table 1 with respect to the whole raw material fiber. This second raw fiber is mixed with the first raw fiber in the raw cotton feeder 110.

Using these raw material fibers, a nonwoven fabric was produced using the apparatus 100 shown in FIG. However, as the card machine in the apparatus 100, the one shown in FIG. 4 was used. The operating conditions of each part in the apparatus 100 were as shown in Table 1. The card machine shown in FIG. 4 is a parallel card machine, and the pre-cylinder 123 is provided with three sets of strippers and workers, and the main cylinder 127 is provided with six sets of strippers and workers. One of the calendar rollers was made of iron and the other was made of paper. In this manner, a nonwoven fabric 10 having a basis weight of 25 g / m ² having the pattern shown in FIG. 1 was obtained.

  In the card machine shown in FIG. 4, the main cylinder 127 has a diameter of 950 mm, and the pre-cylinder 123 has a diameter of 500 mm. The peripheral speed of the main cylinder 127 was 1050 m / min. The peripheral speed of the worker 125 arranged in the main cylinder 127 was as shown in Table 1.

  Regarding the clearance between the three workers 151a-151c arranged in the pre-cylinder 123 and the pre-cylinder 123, the clearance between the first worker 151a located on the most upstream side and the pre-cylinder 123 is as shown in Table 1. did. The clearance between the second worker 151b located immediately downstream of the first worker 151a and the pre-cylinder 123 was set to 0.5 mm. The clearance between the third worker 151c located on the most downstream side and the pre-cylinder 123 was set to 0.3 mm.

  The clearance between the three workers 125a-125f arranged in the main cylinder 127 and the main cylinder 127 is 0.5 mm (first worker 125a) and 0.5 mm (second worker 125b) from the upstream side to the downstream side. 0.4 mm (third worker 125c), 0.4 mm (fourth worker 125d), 0.3 mm (fifth worker 125e), and 0.3 mm (sixth worker 125f).

[Examples 2 to 11 and Comparative Examples 1 to 8]
A nonwoven fabric was obtained in the same manner as in Example 1 except that the conditions shown in Table 1 were used.

[Evaluation]
About the nonwoven fabric obtained by the Example and the comparative example, evaluation shown in Table 1 was performed. In the same table, the number of small fiber masses is a result obtained by counting those having an area determined by image analysis of 0.5 mm ² or more. The touch was evaluated by the following method.
That is, the sample was prepared and the touch was evaluated by the average score of the touch of ten panelists. Specifically, a box is prepared in which the sample cannot be seen by the evaluator and only both hands can be inserted, and one 20 cm x 30 cm sample placed on cardboard in the box is used as a panel. Touch and evaluate the touch in 10 levels from 1 to 10. The degree that the panel feels comfortable is 10 points maximum and 1 point minimum. The arithmetic average value (rounded value) of 10 people is taken as the final evaluation score. All the panelists who rated one point answered that they were stiff, hard, or had a foreign body sensation.

  As is clear from the results shown in Table 1, in the nonwoven fabric obtained in each example, the dark portion and the thin portion of the formation are alternately extended in stripes with irregular widths and lengths. It was a thing. In addition, a plurality of small fiber lumps having an irregular shape that is darker than the texture of the nonwoven fabric were randomly distributed in a scattered manner throughout the nonwoven fabric. Furthermore, the nonwoven fabric obtained in each of the examples had a good touch. Although not shown in the table, when the portion of the small fiber mass in the nonwoven fabric obtained in each example was observed with an electron microscope, fine irregularities were formed on the surface of the constituent fiber of the small fiber mass. It was confirmed.

  In contrast, the nonwoven fabrics of Comparative Examples 1 and 2 manufactured under conditions where the first raw fiber is thick, the second raw fiber (end cut) is not used, and the peripheral speed of the worker is high are recognized as small fiber masses. I couldn't. In particular, Comparative Example 1 in which the web was embossed before air-through processing was harder than Comparative Example 2 in which the embossing was not performed.

  In Comparative Examples 3 and 4 in which the calendering was not performed even when the second raw fiber (end cut) was used, a small fiber lump was recognized, but hardness due to the small fiber lump was perceived.

DESCRIPTION OF SYMBOLS 10 Nonwoven fabric 20 Dense part 21 Thin part 30 Small fiber lump 110 Raw cotton supply apparatus 120 Card machine 125 Worker 127 Main cylinder 130 Air through apparatus 140 Calendar apparatus 141 Calendar roll (up)
142 Calendar roll (bottom)

In relation to the thickness of the nonwoven fabric 10, the nonwoven fabric 10 was measured under a pressure of 7.64 kPa at the position where the small fiber mass 30 was arranged (the tip of the probe is a disk and the diameter is 5 mm). the thickness of 10 was used as a T1, when the thickness of the nonwoven 10 measured under the same pressure at a position where the small fiber agglomerations 30 is not placed was T2, the difference in thickness is defined by T3 = T1-T2 T3 Is 1 mm or less. That is, the thickness difference between the position where the small fiber mass 30 is arranged and the other positions is small. As described above, since the small fiber mass 30 is a mass in which the constituent fibers of the non-woven fabric 10 are densely gathered, there is a tendency to exhibit a hard feel, so that the difference between the thickness T2 and the thickness T1 is reduced. Thus, when the surface of the nonwoven fabric 10 is touched, the hardness due to the small fiber mass 30 is hardly perceived. As a result, the touch of the nonwoven fabric 10 is improved. From the viewpoint of making this effect more remarkable, T3 is 0 mm or more, preferably 0.1 mm or less, and more preferably 0.05 mm or less.

The doffer 128 receives the web on the main cylinder 127 that rotates at a high speed at a low speed, thereby increasing the weight of the web. Condenser roller 129 is rotated further slower than doffer 128, receiving the web on the doffer 128, together reshape the web, is intended to align the feeding of the web to the transfer speed of the take-off conveyor 131. The doffer 128 and the condenser roller 129 randomize the fiber arrangement by repeatedly delivering the web.

The spread body 11 obtained by opening the raw fiber in the raw cotton opening section 110 is transported to the web forming section 120 by the transport belt 112 , and the web 12 is formed. Specifically, the spread body 11 is supplied to the pre-cylinder 123 via the feed roller 121 and the take-in roller 122 and pre-opened. The pre-opened opened body 11 is peeled off from the pre-cylinder 123 by the transformer roller 124 and supplied to the main cylinder 127. And with respect to the spread body 11 supplied on the main cylinder 127, using the plurality of workers (four pairs in FIG. 2) 125 and the stripper 126, the operation of moving the spread body 11 to the worker 125, By repeating the operation of returning the spread body 11 transferred to the worker 125 to the main cylinder 127 by the stripper 126, a web is formed. As in the apparatus 100 shown in FIG. 2, it is preferable to use an apparatus having two opening cylinders of a main cylinder 127 (for example, φ950 mm) and a pre-cylinder 123 (for example, φ500 mm).

When employing the above operating conditions, the peripheral speed of the worker 125 is preferably 70 m / min or less, more preferably 50 m / min or less, and even more preferably 30 m / min or less .

<12> An absorbent article using the nonwoven fabric according to any one of <1> to <11> as a member.
<13> The absorbent article according to <12>, wherein the nonwoven fabric is used as an exterior material.
<14> The absorbent article according to <13>, which is a disposable diaper.
<15> In a method for producing a nonwoven fabric having a step of using short fibers as raw materials, forming a web by a card method, and then blowing hot air to the web by an air-through method to fuse the intersections of the fibers,
After the fibers are fused to obtain an air-through nonwoven fabric, a pair of smooth rolls are used, and the linear pressure between the rolls is set to 100 N / cm or more and 1500 N / cm or less, and the air-through nonwoven fabric is subjected to calendering. The manufacturing method of a nonwoven fabric which reduces the difference in thickness by the position where the small fiber lump is arrange | positioned, and the position where this small fiber lump is not arrange | positioned .
<16> The linear pressure between the rolls is preferably set to 100 N / cm or more, particularly 300 N / cm or more, further 700 N / cm or more, and set to 1500 N / cm or less, particularly 1300 N / cm or less, and further 1000 N / cm or less. The manufacturing method as described in said <15>.

Claims (9)

A non-woven fabric manufactured by an air-through method,
In the non-woven fabric, a plurality of small fiber masses that are darker than the formation of the non-woven fabric are dispersed and arranged in a scattered manner over the entire area of the non-woven fabric,
The thickness of the nonwoven fabric measured under a pressure of 7.64 kPa at the position where the fibril mass is arranged is T1, and the thickness of the nonwoven fabric measured under the same pressure at the position where the fibril mass is not arranged. A nonwoven fabric having a thickness difference T3 defined by T3 = T1-T2 of 1 mm or less when T2.   The nonwoven fabric according to claim 1, wherein at least one of the small fiber masses is arranged in an area of 10 cm square on average.   In the said nonwoven fabric, the site | part with a deep formation and the site | part with a thin formation are extended alternately in stripe form.   The nonwoven fabric according to any one of claims 1 to 3, wherein the reflectance per basis weight is 1.4% / gsm or more and 5.0% / gsm or less. In the method for producing a nonwoven fabric having a step of using short fibers as raw materials, forming a web by a card method, and then blowing hot air to the web by an air-through method to fuse the intersections of the fibers,
After the fibers are fused to obtain an air-through nonwoven fabric, a pair of smooth rolls are used, and the linear pressure between the rolls is set to 100 N / cm or more and 1500 N / cm or less, and the air-through nonwoven fabric is subjected to calendering. The manufacturing method of a nonwoven fabric which reduces the difference in thickness by the position where the small fiber lump is arrange | positioned, and the position where this small fiber lump is not arrange | positioned.   The manufacturing method according to claim 5, wherein the web is formed by setting a speed of a worker in the card machine used for forming the web to 30 m / min or less.   The manufacturing method according to claim 5 or 6, wherein the short fiber has a thickness of 0.5 dtex or more and 2.5 dtex or less.   By using short fibers obtained by subjecting a non-woven fabric piece to defibration treatment as a part of the short fibers used as a raw material, a plurality of the small fiber masses are formed throughout the web during the formation of the web. The manufacturing method as described in any one of Claims 5 thru | or 7 disperse | distributed and arrange | positioned over a dot shape over. Perform the calendering using a pair of smooth rolls,
The manufacturing method according to any one of claims 5 to 8, wherein a speed difference of 0.1% or more is set between the rolls.