JP2020058860A - Sanitary paper roll - Google Patents

Abstract

To provide a sanitation paper roll that is compact but bulky despite the elongated wound length thereof and has excellent water absorption and strength.SOLUTION: A two-ply sanitation paper roll 10 with embossment 2 has a basis weight of one ply of 13 to 29 g/m, a paper thickness of 1.0 to 3.2 mm/10 pcs, a roll length of 15 to 60 m, a roll density of 0.4 to 1.0 m/cm, the number of pieces of embossment of 300 to 1600 pcs/100 cm, an average area per embossment of 1.0 to 7.0 mm/embossment and an embossment depth of 0.10 to 0.60 mm.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a 2-ply sanitary paper roll that can be suitably used for paper towels, kitchen towels, and the like.

In order to secure the texture of a sanitary paper roll such as a kitchen towel, ease of wiping, water absorption, etc., embossing is applied (Patent Document 1).
Further, in recent years, from the viewpoint of portability and storability, there has been a demand for a compact roll having a long winding length and a large winding diameter.

JP 2003-73999 JP

However, in general, there is a problem that the embossing depth must be reduced in order to make a long-winding roll into a compact product having a small winding diameter. When the embossing depth is small, the water absorbency (Water-g / m ² , Water-g / g) is poor and the function as a paper towel is reduced. On the other hand, if the emboss is deeply inserted, the winding diameter becomes large, so that it becomes difficult to realize the compactness of the roll.
Therefore, an object of the present invention is to provide a sanitary paper roll which is compact and bulky while having a long winding length and which is excellent in water absorption and strength.

The present inventors have defined the area (size) and the total number (total area) of individual embosses, the emboss depth, the paper thickness, the basis weight, and the winding density, thereby making it possible to increase the winding length while achieving a compact size. It has been found that it is possible to secure bulkiness and water absorption.
Of these, it was found that the paper thickness was reduced and the water absorption was lowered when the area (size) of each emboss was too large or too small. Similarly, it was found that even if the number of embosses was too small, the paper thickness was reduced and the water absorption was reduced.
Therefore, the embossing depth is made small so that it is compact even if the winding length is made long, and the decrease in water absorption due to it is suppressed by specifying the area (dimension) and total number (total area) of each embossing. I succeeded in doing so.
In addition, by limiting the paper thickness and basis weight within a predetermined range, both strength and water absorption and compactness were achieved.

In order to solve the above problems, the sanitary paper roll of the present invention is a two-ply sanitary paper roll having embossing, in which the basis weight of one ply is 13 to 29 g / m ² , and the paper thickness is 1.0 to 3.2 mm /. Ten sheets, the winding length is 15 to 60 m, the winding density is 0.4 to 1.0 m / cm ² , the number of the embosses is 300 to 1600/100 cm ² , and the average area per one emboss is 1.0 to. 7.0 mm ² / piece, and the depth of the emboss is 0.10 to 0.60 mm.

The water absorption amount per area is preferably 105 to 250 Water-g / m ² .
The amount of water absorption per mass is preferably 5.5 to 10.7 Water-g / g.
The specific volume is preferably 5 to 15 cm ³ / g.
The 2-ply DGMT is preferably 6.0 to 15.0 N / 25 mm.
The winding diameter is preferably 82 to 155 mm.
The area ratio of embossing is preferably 7 to 60%.

  According to the present invention, it is possible to obtain a sanitary paper roll which is compact and bulky and has excellent water absorption and strength while having a long winding length.

It is a perspective view showing appearance of a sanitary paper roll concerning an embodiment of the present invention. It is a figure which shows the measuring method of the area of embossing. It is a figure which shows the specific measuring method of the area of embossing. It is a figure following FIG. It is a figure which shows the relationship between the average area (size) per embossing, and a sheet gap (bulkiness). It is a figure which shows an example of an embossing apparatus. It is a figure which shows the measuring method of water absorption.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described, but these are given for the purpose of illustration and do not limit the present invention.
As shown in FIG. 1, a sanitary paper roll 10 according to an embodiment of the present invention is a sanitary paper roll obtained by winding a sheet 10x stacked on two plies in a roll shape, and the basis weight of one ply is 13 to 29 g /. m ² , the paper thickness is 1.0 to 3.2 mm / 10 sheets, the winding length is 15 to 60 m, the winding density is 0.4 to 1.0 m / cm ² , and the predetermined embossing described later is provided.
The surface of the sheet 10x on the outer side of the roll is the roll surface (or the surface of the sheet) 10a, and the inner surface of the roll is the back surface of the roll (or the back surface of the sheet) 10b.
As a method of adjusting the roll density of the sanitary paper roll within the above range, there is a method of adjusting the winding strength of the roll with a roll winder (particularly a surface type) while adjusting the basis weight and the paper thickness within predetermined ranges.

When the roll length of the sanitary paper roll 10 is less than 15 m, the roll length per roll becomes short, the roll replacement frequency increases, and space saving during storage cannot be achieved. A roll having a roll length of more than 60 m has a roll diameter DR of more than 155 mm and is difficult to fit in a roll holder or the like.
The winding length is preferably 20 to 50 m, more preferably 30 to 40 m.

The winding density is represented by (winding length × number of plies) ÷ (cross-sectional area of roll). The cross-sectional area of the roll is represented by {cross-sectional area of outer diameter (roll diameter DR) portion of roll}-(cross-sectional area of core outer diameter portion). The core outer diameter DI (see FIG. 1) is the diameter of the center hole of the roll. When the core (core paper tube) is mounted inside the roll, the core outer diameter corresponds to DI.
If the winding density is less than 0.4 m / cm ² , the winding diameter DR will exceed 155 mm, making it difficult to fit in a roll holder or the like. When the winding density exceeds 1.0 m / cm ² , the paper thickness is low and the water absorption is poor, or the basis weight is low and the paper is easily torn.
The winding density is preferably 0.5 to 0.9 m / cm ² , and more preferably 0.6 to 0.8 m / cm ² .

A winding diameter DR of 82 to 155 mm is preferable because the winding length is increased to 15 m or more and easily accommodated in a roll holder or the like. If the winding diameter DR is less than 82 mm, the winding length per roll becomes short, the frequency of roll replacement may increase, and space saving during storage may not be achieved. If the winding diameter DR exceeds 155 mm, it may be difficult to fit it in a roll holder or the like.
The winding diameter DR is more preferably 95 to 140 mm, further preferably 110 to 125 mm.

When the basis weight per sheet (1 ply) of the sheet 10x is less than 13 g / m ² or the paper thickness is less than 1.0 mm / 10 sheets, the strength and the paper thickness are reduced and the water absorption is Inferior. When the grammage per sheet 10x exceeds 29 g / m ² or the paper thickness exceeds 3.2 mm / 10 sheets, the sheet becomes thick, and the winding diameter DR of the roll wound 15 m or more is 155 mm. It becomes difficult to fit in the roll holder.
The grammage per sheet of the sheet 10x is more preferably 16 to 26 g / m ² , and further preferably 19 to 23 g / m ² . The sheet thickness of the sheet 10x is more preferably 1.2 to 2.5 mm / 10 sheets, and further preferably 1.4 to 2.0 mm / 10 sheets.
An embossing condition is defined as a method for adjusting the basis weight and the sheet thickness of each sheet 10x within the above range.

<Emboss>
The following embossing is applied to the sanitary paper roll 10 (sheet 10x) of the present invention. The embossing may be single embossing or double embossing, but double embossing is preferable. In the double embossing, a sheet of a two-ply sanitary paper roll is embossed, and the two plies are laminated so that the convex surfaces of the emboss of each sheet face each other.
By using double embossing, it is easy to increase the paper thickness and specific volume, and it is easier to increase water absorption. Further, in the case of double embossing, it is possible to make two plies by edge embossing or glue, but it is preferable to use glue because the shape of the emboss can be easily maintained. Moreover, as the double embossing, a nested embossing is preferable.

<Average area (size) per embossing>
The average area per embossing is 1.0 to 7.0 mm ² / piece. When the average area is less than 1.0 mm ² / piece or more than 7.0 mm ² / piece, the paper thickness becomes low and the water absorption is lowered.
The reason for this will be described with reference to FIG.
FIG. 5A shows a case where the average area per embossing is 1.0 to 7.0 mm ² / piece, and since the area (size) of each embossing 2 is appropriate, double embossing ( In the case of "nested embossing", the embossing 2 provided on each of the sheets 10a and 10b is overlapped with a proper gap through the glue 6, and the sheet gap becomes large and bulky, resulting in high water absorption.
On the other hand, as shown in FIG. 5B, when the area (size) of each embossing 2 becomes too small, the embossing 2 provided on each of the sheets 10a and 10b becomes a double embossing (nested embossing). Are closely aligned, the sheet gap is reduced, the bulk is reduced, and the water absorption is reduced.
Further, as shown in FIG. 5C, even if the area (size) of each embossing 2 becomes too large, the embossing provided on each of the sheets 10a and 10b is changed to double embossing (nested embossing). 2 are closely aligned, the sheet gap is reduced, the bulk is reduced, and the water absorption is reduced.

  In the case of single embossing, the reason is not clear, but by defining the average area per embossing in the above range, the paper thickness increases and the water absorption improves, as in the case of double embossing.

Preferably has an average area per embossed is 1.5~5.5mm ^2, more preferably 2.0 to 4.0 mm ^2.

<Number of embosses>
The above-mentioned embosses are formed in a number of 300 to 1600 pieces / 100 cm ² . It exceeds 1600/100 cm ^2, even the number of the embossed is less than 300/100 cm ^2, the sheet thickness becomes water absorption is decreased lower.
This is because when the number of embosses is too small below 300/100 cm ² , even if the average area per emboss is 1.0 to 7.0 mm ² / piece, the spacing between adjacent embosses is large. This is because the paper thickness becomes too small and the paper thickness becomes small at a portion where the embossing interval is large, which is close to the state where there is no embossing. This is because if the number of embosses exceeds 1600/100 cm ² and becomes too large, the average area per emboss becomes smaller than 1.0 mm ² / piece.
The number of the embosses is preferably 450 to 1200 pieces / 100 cm ² , and more preferably 600 to 900 pieces / 100 cm ² .

<Embossing depth>
The emboss depth is 0.10 to 0.60 mm.
If the depth of the emboss is less than 0.10 mm, the water absorption is reduced. On the other hand, when the emboss depth exceeds 0.60 mm, the winding diameter DR exceeds 155 mm, and it becomes difficult to fit the roll holder in a roll holder or the like.
The emboss depth is preferably 0.15 to 0.47 mm, more preferably 0.20 to 0.35 mm.

<Measurement of emboss area and number>
The average area per emboss is obtained by measuring the height difference of the emboss using a microscope.
As the microscope, a product name “One-shot 3D measuring macroscope VR-3100” manufactured by KEYENCE can be used. The product name “VR-H1A” can be used as software for observing, measuring, and analyzing images on a microscope. Further, the measurement conditions are such that the magnification is 12 times and the visual field area is 24 mm × 18 mm. The measurement magnification and the visual field area may be appropriately changed depending on the size of the emboss to be obtained. The three-dimensional measuring machine and the contour shape measuring machine measure points and lines, but in the case of the above-mentioned microscope, the entire surface is measured, so that the entire shape and undulation are easy to understand.

  As shown in FIG. 2, the area of the embossing is measured by measuring the length a of the longest part of the peripheral edge fr of the embossing and the length b of the longest part in the direction perpendicular to the length a, and a xb Calculate as S.

  FIG. 3 shows a specific method for measuring the embossed area (length b). FIG. 3A shows a height profile on the XY plane by a microscope, and it can be seen that the height of the sheet surface is represented by shading. The dark portion in FIG. 3 (a) indicates each emboss 2, and when a line segment AB that crosses the length b of the longest part of one of these is drawn, as shown in FIG. 3 (b). A height (measurement sectional curve) profile of the embossing 2 is obtained. Here, since the convex portion and the concave portion of the emboss can be seen from the light and shade of the color of the XY plane image, the line segment AB can be determined so as to cross the portion where the convex portion and the concave portion are adjacent. In the case of measuring the length a of the longest part of the emboss 2, the line segment AB is in the vertical direction.

The number of embosses is measured by visually selecting an arbitrary 100 cm ² site in the entire width of the sheet and from the entire area between two perforations adjacent in the lengthwise direction. In addition, when the area of 100 cm ² cannot be selected, such as when knurling (edge embossing) is performed, the number of embossed areas is measured for the measurable areas except the area that cannot be measured by knurling (edge embossing) processing, It is calculated as the number of embossments per 100 cm ² .

<Measurement of emboss depth>
Further, the emboss depth is obtained by measuring the height difference of the emboss described above using the microscope.

Here, the height profile in FIG. 3B is a (measurement) cross-sectional curve S that represents the unevenness of the actual sample surface of the sheet, but noise (whether there is a fiber lump on the surface of the sheet or the fiber is a whisker) It also includes a steep peak due to a stretched portion or a fiber-free portion, and it is necessary to remove such a noise peak when calculating the height difference of the unevenness.
Therefore, as shown in FIG. 4, a “contour curve” W is calculated from the sectional curve S of the height profile, and two inflection points P1 and P2 that are convex upward in the contour curve W and the inflection The minimum value sandwiched between the points P1 and P2 is obtained and is set as the minimum depth value Min. Further, the average value of the depth values of the inflection points P1 and P2 is set as the maximum depth value Max.

  In this way, emboss depth = maximum value Max−minimum value Min. Further, the distance (length) of the inflection points P1 and P2 on the XY plane is defined as the length of the longest part a. The "contour curve" is a wavelength shorter than λc: 800 μm (where λc is a "filter that defines the boundary between the roughness component and the waviness component" described in JIS-B0601 "3.1.1.2") from the sectional curve. It is a curve obtained by removing a component of surface roughness by a low pass filter. If λc is set to be equal to or larger than the interval P1 between adjacent embosses (this is referred to as an emboss pitch), the peak may be recognized as noise. Therefore, λc is set to be less than the emboss pitch. For example, when the emboss pitch is 800 μm or less, for example, λc: 250 μm is set. As for the interval of P1 between the adjacent embosses, P1 and P2 are similarly obtained for the next emboss connected to the left or right of FIG. 4, and the interval of the two P1 when the adjacent embosses are aligned with P1, P2, and P1. is there.

  Similarly, in FIG. 3A, the emboss depth and the length of the longest part a are measured also for the longest part a, and the larger one of the emboss depths of the longest part a and b is determined. To be adopted as. The above measurement is performed for any 10 embossments 2 on the surface 10a of the sheet 10x, and the average value thereof is adopted as the final emboss depth. Further, the lengths of the longest portions a and b are respectively measured for the ten embosses 2, and each average value is adopted as the final length of the longest portions a and b, and a × b is the average area.

When measuring embossing, the measurement surface is on the surface 10a side regardless of whether it is single embossing or double embossing.
Further, when selecting any 10 embosses by measuring the embossing, the portion corresponding to 10% of the roll length of the sanitary paper roll 10 from the end of the outer roll of the sanitary paper roll 10 (the position where the sheet starts to be used) is selected. taking measurement. For example, when the winding length is 30 m, the measurement is made at a portion of 30 m × 10% = 3 m from the end. When 10% of the winding length hits the perforation, the outer winding side of the perforation is measured.

  The means for ensuring the water absorption of the sheet (sheet) 10x is not limited to embossing as long as it gives unevenness to the surface, and for example, uneven web may be used to make unevenness at the time of paper making. Further, in this case, the unevenness corresponds to embossing.

The area ratio of the emboss is preferably 7 to 60%. Here, the area ratio of embossing is a ratio of the total area of embossing per unit area of the sheet. The total area of embossing is calculated from the above-mentioned average area per embossing and the number of embossing per unit area.
If the area ratio of embossing is less than 7% or more than 60%, the water absorption is lowered. Even if the area (dimension) of each embossing is within the above range, when the number of embossing is small, the area ratio becomes lower than 7%, the paper thickness becomes low, and the water absorption may be poor. Even if the area (dimension) of each embossing is within the above range, the area ratio may exceed 60% and increase when the number of embossing is large, and similarly the paper thickness may decrease and the water absorption may be poor. is there.

The water absorption amount of the sheet 10x stacked in two plies is preferably 105 to 250 Water-g / m ² . If the water absorption amount is less than 105 Water-g / m ² , the water absorption may decrease, and if it exceeds 250 Water-g / m ² , the cost may increase or the texture may become hard.
More preferably water absorption amount is 130~220Water-g / ^{m 2,} further preferably 150~190Water-g / ^{m 2.}

It is preferable that the water absorption of the sheet 10x stacked in two plies is 5.5 to 10.7 Water-g / g. If the water absorption amount is less than 5.5 Water-g / g, the water absorption decreases, and if it exceeds 10.7 Water-g / g, the paper thickness increases and the winding diameter DR also increases, making it difficult to fit in a roll holder or the like. Sometimes.
The water absorption amount is more preferably 6.5 to 9.7 Water-g / g, further preferably 7.5 to 9.0 Water-g / g.

In addition, as a unit of water absorption, Water-g / m ² is the water absorption per sheet area, and if the basis weight is increased, Water-g / m ² is improved, but the cost is increased accordingly. On the other hand, Water-g / g is the amount of water absorption per mass of the sheet. Even if the basis weight is increased, Water-g / g does not simply improve, and the paper thickness (specific volume) of the sheet is increased. Therefore, Water-g / g also becomes high.
That is, by prescribing a suitable range of both Water-g / m ² and Water-g / g as a unit of water absorption, it is possible to secure water absorption while achieving both cost and paper thickness (bulkness).

The water absorption is measured as shown in FIG. First, a sheet 10x stacked on two plies is collected and cut using a square die having a size of 7.62 cm (3 inches) to form a rectangular test piece with a side of 7.62 cm. The mass of the test piece before water absorption is measured with an electronic balance. The test piece is set in a holder (a jig that fixes three points of the test piece, and the jig is made of a metal that does not absorb water).
Next, distilled water is put into a commercially available vat to a depth of 1 cm, and the test piece set in the holder is immersed in distilled water for 2 minutes. After dipping for 2 minutes, the test piece is taken out of the distilled water together with the holder, and the strip 210 is attached to one corner portion 200d of the test piece 200 as shown in FIG. The strip 210 is formed by cutting a 1-ply general kitchen towel paper product into a size of 2 mm in width and 15 mm in length, and affixing it to a 6 mm portion from the corner 200d of the test piece toward the center. Next, the holder and the test piece 200 are hung on a rod installed in an empty water tank with the corner 200a facing the corner 200d facing upward, and the lid of the water tank is closed and left for 30 minutes. Then, the holder 220 and the test piece 200 are taken out from the water tank, the band 210 and the holder 220 are removed, and the mass of the test piece 200 is measured by an electronic balance. From the change in mass of the test piece 200 before and after soaking in distilled water, the water absorption of distilled water per 1 m ^{2 of} the test piece (Water-g / m ² ) is calculated. Further, by dividing the water absorption amount (Water-g / m ² ) by the basis weight of the test piece, the water absorption amount (Water-g / m ² ) / basis weight (g / m ² ) = water absorption amount (Water-g / g) is calculated. The measurement was performed 5 times for each sample, and the average value was adopted.
In addition, this measurement is performed in accordance with JIS-P8111 at a temperature of 23 ± 1 ° C. and a humidity of 50 ± 2%. Also, keep distilled water at 23 ± 1 ° C.

The specific volume of the sheet 10x is preferably 5 to 15 cm ³ / g. If the specific volume is less than 5 cm ³ / g, the water absorption may be poor. On the other hand, when the specific volume exceeds 15 cm ³ / g, the bulk (bulkness) becomes too high, and the winding diameter DR exceeds 155 mm, which may make it difficult to fit in a roll holder or the like.
The specific volume is more preferably 6~12cm ³ / g, more preferably from 7~9cm ³ / g.
The specific volume is expressed by the volume cm3 per unit g, which is obtained by dividing the paper thickness to be measured as described later by the basis weight.

It is preferable that the sheet 10x stacked in two plies has a DGMT of 6.0 to 15.0 N / 25 mm.
When the tensile strength in the vertical direction during drying based on JIS P8113 is DMDT (Dry Machine Direction Tensile strength) and the tensile strength in the horizontal direction during drying is DCDT (Dry Cross Direction Tensile strength), the strength DGMT (Dry Geometric Mean Tensile strength) is represented by (DMDT × DCDT) ^1/2 . Note that DMDT and DCDT are measured with respect to the product of the sheet 10x that is still stacked in two plies.
If the DGMT is less than 6.0 N / 25 mm, the water absorbability may decrease and the image may easily shake. When DGMT exceeds 15.0 N / 25 mm, the cost may increase or the texture may become hard (rough).
The DGMT is more preferably 7.6 to 12.5 N / 25 mm, further preferably 9.1 to 11.1 N / 25 mm.

The DMDT is preferably 11.0 to 27.0 N / 25 mm, more preferably 14.5 to 22.5 N / 25 mm, and most preferably 16.5 to 20.0 N / 25 mm. The DCDT is preferably 3.3 to 8.3 N / 25 mm, more preferably 4.0 to 7.0 N / 25 mm, and most preferably 4.8 to 6.2 N / 25 mm.
When DMDT and DCDT are less than the above-mentioned values, water absorption may decrease and the image may easily shake. If DMDT and DCDT are higher than the above values, the cost may increase or the texture may become hard.
In addition, the flow direction of the sanitary paper is referred to as "longitudinal direction", and the direction perpendicular to the flow direction is referred to as "transverse direction".

The sheet may consist of 100% by weight of wood pulp and may contain waste paper pulp and non-wood pulp. In order to obtain the target quality, it is preferable to use NBKP (softwood kraft pulp): LBKP (hardwood kraft pulp) = 25 to 70:30 to 75 (mass ratio) as a raw material, and a more preferable range is NBKP: LBKP = 35-60: 40-65, and a more preferable range is NBKP: LBKP = 40-55: 45-60.
Pulp manufactured from Eucalyptus genus Eucalyptus represented by Eucalyptus grandis and Eucalyptus globulus is preferable as the material of the above LBKP. Further, up to 100 parts by mass of waste paper pulp derived from a milk carton may be contained with respect to 100 parts by mass of the NBKP and LBKP pulps. Since waste paper pulp has a large quality variation, and if the blending ratio increases, it has a great influence on the quality of the product, especially the softness, so that it is preferably 50 parts by mass or less, more preferably 100 parts by mass with respect to 100 parts by mass of the pulp of NBKP and LBKP. It is desirable to add 30 parts by mass or less, more preferably 10 parts by mass or less, and most preferably 0 parts by mass.

  In order to secure proper strength to the sheet, it is possible to mix the raw materials by an ordinary means and adjust the strength by beating the pulp fiber. As the beating to obtain the target quality, in the pulp before and after beating, the commercially available virgin pulp has a Canadian standard freeness of 20 to 350 ml, more preferably 50 to 300 ml, further measured by JIS-P8121. Preferably 100-250 ml reduce freeness.

When a virgin raw material is used for the stock, the sheet can be prepared by blending a softwood kraft pulp and a hardwood kraft pulp having a fiber length and a fiber roughness within a certain range in a specific range for papermaking. As an additive to paper materials, depending on the required quality of the final product, softeners including debonder softeners, bulking agents, dyes, dispersants, dry paper strength enhancers, drainage improvers, pitch control agents, absorbency Improvers, wetting agents and the like can be used. In particular, it is preferable to add known dry paper strength enhancer and wet paper strength enhancer so as to obtain desired strength.
When using a waste paper material as a sheet, the same treatment as in the case of the virgin type is performed.

  The sanitary paper roll of the present invention can be manufactured, for example, in the following order: (1) papermaking and creping, (2) embossing and roll winding. Further, known processing such as calendar processing can be performed.

(1) Paper making and creping First, a web is made from the above stock on a wire part of a known paper machine, and moved to a felt of a press part. Examples of the wire part method include a round net type, a long net (Ford linear) type, a suction breast type, a short net type, a twin wire type, and a crescent former type.
Then, the web is mechanically compressed with a suction pressure roll, a pressure roll without a suction, a press roll, or the like, or dehydration is continued by a dehydration method such as ventilation drying with hot air. Suction pressure rolls or pressure rolls without suction are also used as a means to move the web from the press part to the Yankee dryer.

  Here, a roll press may be placed in the loop of the uneven fabric instead of the felt, and the wet paper may be made uneven by increasing the specific volume. However, in this case, the moisture content of the wet paper becomes high, and the energy for drying with the Yankee dryer may increase. Therefore, it is preferable to perform the roll press using the felt without using such a fabric. As the textured fabric, the number of the warp and weft threads on the top surface (the surface where the wet paper and the wire contact) is 20 to 70 / 2.54 cm, and the wire diameter of the warp and the weft is 0.21 to 0.70 mm. One made of a mesh-like wire in which the warp and the weft are woven. Therefore, the number of warp and weft threads on the top surface (the surface where the wet paper web and the wire contact) is 70 to 200 threads / 2.54 cm, preferably 80 to 170 threads / 2.54 cm, and more preferably 90 to 140 threads / 2.54. It can be cm. In addition, if the wire diameter of the warp and weft is 0.08 to 0.30 mm, preferably 0.09 to 0.27 mm, and more preferably 0.10 to 0.24 mm, it is a fabric made of a mesh-like wire with a fine mesh. Since it has less unevenness, it may be used for roll pressing. The wire diameter on the top surface is a weighted average value of the number of wires and the wire diameter.

The web transferred to the Yankee dryer is dried by a Yankee dryer and a Yankee dryer hood, then creped by a creping doctor, and wound on a reel part.
Creping (making wavy wrinkles called crepes) is the mechanical compression of paper in the machine direction (the direction of sheet travel on a paper machine). When the sheet web is manufactured, the web on the Yankee dryer is peeled off by the creping doctor and wound on the reel part, but the speed difference between the Yankee dryer and the reel part (speed of the reel part ≤ speed of the Yankee dryer). As a result, crepes (wrinkles) are formed by the creping doctor.
The quality required for the sheet, that is, bulkiness, softness, water absorption, surface smoothness, aesthetics (crepe shape) and the like are affected by the speed difference. Although it depends on the conditions such as the speed difference, the basis weight of the web on the reel after creping is about 14 to 31 g / m ² , which is heavier than the basis weight of the web on the Yankee dryer before creping. The grammage is preferably 17 to 28 g / m ² , more preferably 20 to 25 g / m ² , and should be slightly higher than the grammage of the product in consideration of stretching of the sheet during roll winding. Is preferred. If it exceeds the above range, the strength may be increased and the paper may become stiff, and if it is less than the above range, the strength may be weak and the paper may be easily torn.

Here, the crepe rate based on the speed difference between the Yankee dryer and the reel is defined by the following equation.
Crepe rate (%) = 100 x (Yankee dryer speed (m / min) -reel speed (m / min)) / reel speed (m / min)
The quality and operability are generally determined by the creping conditions, and the operating conditions that optimize the creping conditions are important matters for those skilled in the art. In the present invention, the crepe ratio in producing the sheet is preferably 10 to 50%, more preferably 20 to 40%, and most preferably 25 to 35%.

(2) Embossing process and roll winding process The original fabric is embossed by, for example, the embossing device shown in FIG. 6 to obtain the sanitary paper roll 10.
In the embossing device of FIG. 6, the sheet on the roll surface 10a side is passed between the convex embossing roll 40 on which the convex surface 40x of the embossing 2 is formed and the opposing rubber pressing roll, and the embossing 2 is applied. Similarly, the one-ply sheet on the roll back surface 10b side is passed between the convex embossing roll 40 on which the convex surface 40x of the embossing 2 is formed and the opposing rubber pressing roll, and the embossing 2 is applied. Then, after appropriately applying an adhesive (ply bond) 6 to the embossed convex surfaces of both sheets, the two embossed convex surfaces of each sheet are laminated and adhered to the two plies by a stacking roll, Roll up appropriately. Of course, the sheet on the 10a side may be the back surface of the roll, and the sheet on the 10b side may be the front surface side of the roll.
Note that, instead of ply bonding, two plies may be laminated by knurling (edge embossing), but ply bonding is preferable.

The roll winding machine is roughly classified into a surface type and a center type. The surface method is a method in which the winding roll is wound from the outside while being supported by another plurality of drive rolls, and the wound sanitary paper roll 10 can easily control the winding diameter, and the production speed becomes higher. The center system is a method of winding by driving a shaft passing through the center of a winding roll, and the wound sanitary paper roll 10 becomes a relatively soft product and is suitable for a product with delicate embossing. In the present invention, the winding can be carried out by any method, but the surface method is preferable.
Instead of double embossing, single embossing in which two sheets are embossed together may be used. Moreover, you may perform a calendar process as needed.

The embossing depth can be controlled by appropriately adjusting the nip width of the rubber roll (see FIG. 6) facing the embossing roll 40. The nip width varies depending on the characteristics of the roll, but is preferably 20 to 60 mm, more preferably 25 to 50 mm, further preferably 30 to 45 mm. If the nip width exceeds 60 mm, the emboss becomes too strong, the paper thickness becomes high, and the roll diameter DR of the roll becomes large. On the other hand, if the nip width is less than 20 mm, embossing may be weakened and water absorption may be poor. The nip width can be measured using carbon paper. As a measuring method, first, the nip of the embossing roll is released, and the carbon paper and the general copy paper are stacked and set. Next, a nip is applied to the embossing roll. Then release the nip and remove the carbon paper and copy paper. Since the color of the carbon paper at the part where the nip is applied by the embossing roll is transferred to the copy paper, the nip width can be measured.
The embossing depth can be adjusted by narrowing the nip width if the embossing roll has deep irregularities and widening the nip width if the embossing roll has shallow irregularities.

  At the same time, printing, perforation processing, tail sealing, and cutting with a predetermined width can be performed by the roll winding processing machine, and the sanitary paper roll 10 can be manufactured. Further, thereafter, film packaging processing can be carried out to manufacture a package of sanitary paper rolls.

  It is needless to say that the present invention is not limited to the above-described embodiments and covers various modifications and equivalents included in the concept and scope of the present invention.

  The pulp composition (mass%) was NBKP 50% and LBKP 50%, and roll pressing was performed through a felt by a known method to produce paper. After that, embossing was performed by the embossing apparatus 100 shown in FIG. 5 to manufacture a sanitary paper roll.

The following evaluation was performed.
The maximum load until breakage was measured in units of N / 25 mm for a two-ply sheet 10x based on the dry longitudinal tensile strength DMDT and the dry transverse tensile strength DCDT: JIS P8113.
Basis weight: The sheet 10x was measured based on JIS P8124.
Paper thickness: The sheet 10x was measured using a thickness gauge (a dial thickness gauge “PEACOCK” manufactured by Ozaki Seisakusho). The measurement conditions were a measurement load of 3.7 kPa, a probe diameter of 30 mm, a sample placed between the probe and the measuring table, and the gauge when the probe was lowered at a speed of 1 mm or less per second was read. The measurement was performed by stacking 10 sheets 10x (5 pairs of 2 plies). The measurement was repeated 10 times and the measurement results were averaged. Then, the obtained average value per sheet was divided by the number of sheets to obtain the paper thickness per sheet 10x.
Specific volume: The thickness of the sheet 10x was divided by the grammage, and the volume was expressed in cm ³ per unit g.
Water absorption: measured by the method described above.

Roll winding diameter DR: Measured using a diameter rule manufactured by Muratec KDS Co., Ltd. For the measurement, 10 rolls were measured and the measurement results were averaged.
The roll density, the area of embossing, the number and the depth of the roll were measured by the above-mentioned methods.

Sensory evaluation was performed by 20 monitors. The evaluation standard was 5 points. It is good if the evaluation standard is 3 points or more.
Note that the basis weight, tensile strength, thickness, specific volume, winding density, and embossing are measured in the equilibrium state under the temperature and humidity conditions (23 ± 1 ° C, 50 ± 2% RH) specified in JIS-P8111. I went later.
Area per amount of water absorption, 150Water-g / ^{m 2} or more is evaluated 5 points, 130~149Water-g / ^{m 2} is 4 points, 105~129Water-g / ^{m 2} is 3 points, 90~104Water-g / ^{m 2} Was 2 points, and 89 Water-g / m ² or less was 1 point.
The water absorption amount per mass is 5 points for 7.5 Water-g / g or more, 6.5 points for 6.5-7.4 Water-g / g, 4 points for 5.5-6.4 Water-g / g, and 5 points. 3 to 5.4 Water-g / g was 2 points, and 5.2 Water-g / g or less was 1 point.

  The obtained results are shown in Tables 1 to 3.

  As is clear from Tables 1 to 3, in the case of each example in which a predetermined emboss is provided and the basis weight, paper thickness, winding length, and winding density are specified, the winding length is long, yet compact and bulky. It also had excellent properties and strength.

On the other hand, in the case of Comparative Example 1 in which the winding length was less than 15 m, the frequency of roll replacement was high.
In the case of Comparative Example 2 in which the winding length exceeded 60 m, the winding diameter exceeded 155 mm and the roll diameter became large, making it difficult to fit in the paper holder.

In the case of Comparative Example 3 in which the embossing depth is less than 0.10 mm and the paper thickness is less than 1.0 mm / 10 sheets, the winding density exceeds 1.0 m / cm ² and the bulk becomes low (the density becomes high), and the mass The water absorption per unit was inferior.
In the case of Comparative Example 4 in which the emboss depth exceeds 0.60 mm and the paper thickness exceeds 3.2 mm / 10 sheets, the winding density becomes less than 0.4 m / cm ² and the bulk becomes too high (the density is low. Too much), the winding diameter exceeded 155 mm, and the roll diameter became large, making it difficult to fit in the toilet paper holder.

In the case of Comparative Example 5 in which the basis weight is less than 13 g / m ² and the paper thickness is less than 1.0 mm / 10 sheets, the winding density exceeds 1.0 m / cm ² and the bulk becomes low (density becomes low), and water absorption Inferior in strength and inferior in strength.
In the case of Comparative Example 6 in which the basis weight was more than 29 g / m ² , the cost was increased and the strength was too high and it was stiff and inferior in usability.

In the case of Comparative Example 7 in which the average area per embossed piece is less than 1.0 mm ² / piece, the paper thickness is less than 1.0 mm / 10 sheets, and the winding density is more than 1.0 m / cm ² and the volume is low. (Increased density) and poor water absorption per mass.
On the other hand, also in the case of Comparative Example 8 in which the average area per emboss exceeds 7.0 mm ² / piece, the paper thickness is less than 1.0 mm / 10 sheets, and the winding density exceeds 1.0 m / cm ^2. The bulk was low (the density was high) and the water absorption per mass was poor.

In the case of Comparative Example 9 in which the number of embosses is less than 300/100 cm ² , the paper thickness is less than 1.0 mm / 10 sheets, and the winding density is more than 1.0 m / cm ² , resulting in low bulk (high density). ), The water absorption per mass was inferior.
Also in the case of Comparative Example 11 in which the number of embosses was less than 1600/100 cm ² , the paper thickness was less than 1.0 mm / 10 sheets, and the winding density was more than 1.0 m / cm ² and the bulk was low (high density However, the water absorption per mass was inferior.

In the case of Comparative Example 10 in which the number of embosses is less than 300 pieces / 100 cm ² while maintaining the paper thickness at 1.0 mm / 10 sheets or more, the specific volume is less than 5 cm ³ / g and the bulk is low (the density is low). However, the water absorption per mass was inferior.
Also in the case of Comparative Example 12 in which the number of embosses exceeds 1600 pieces / 100 cm ² while maintaining the paper thickness at 1.0 mm / 10 sheets or more, the specific volume becomes less than 5 cm ³ / g and the bulk becomes low ( The density was high) and the water absorption per mass was poor.

  When the commercially available products 1 and 2 were evaluated in the same manner, the winding lengths were all less than 15 m, and the roll replacement frequency was high.

2 Embossing 10 Sanitary paper roll 10x Sanitary paper (sheet)
Roll diameter of DR roll

In order to solve the above problems, the sanitary paper roll of the present invention is a two-ply sanitary paper roll having embossing, in which the basis weight of one ply is 13 to 29 g / m ² , and the paper thickness is 1.0 to 3.2 mm /. Ten sheets, the winding length is 30 to 40 m, the winding density is 0.4 to 1.0 m / cm ² , the number of the embosses is 300 to 1600/100 cm ² , and the average area per one emboss is 1.0. ˜7.0 mm ² / piece, and the depth of the embossing is 0.10 to 0.60 mm.

Claims (7)

A two-ply sanitary paper roll having embossing, one ply having a basis weight of 13 to 29 g / m ² , a paper thickness of 1.0 to 3.2 mm / 10 sheets, a winding length of 15 to 60 m, and a winding density of 0. 4 to 1.0 m / cm ² ,
Sanitary paper in which the number of the embosses is 300 to 1600/100 cm ² , the average area per one emboss is 1.0 to 7.0 mm ² / piece, and the depth of the emboss is 0.10 to 0.60 mm. roll. The sanitary paper roll according to claim 1, wherein the water absorption amount per area is 105 to 250 Water-g / m ² .   The sanitary paper roll according to claim 1 or 2, wherein the water absorption amount per mass is 5.5 to 10.7 Water-g / g. Hygiene paper roll according to any one of claims 1-3 specific volume is 5 to 15 cm ³ / g.   The sanitary paper roll according to any one of claims 1 to 4, wherein the two-ply DGMT is 6.0 to 15.0 N / 25 mm.   The roll of sanitary paper according to any one of claims 1 to 5, which has a winding diameter of 82 to 155 mm.   The sanitary paper roll according to any one of claims 1 to 6, wherein the embossed area ratio is 7 to 60%.