JP6629786B2 - Toilet roll - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toilet roll in which toilet paper wound on two plies is wound.

Toilet paper is commercially available mainly packed in units of 4 rolls or 12 rolls. Because these packages are bulky, the amount that can be carried at the time of purchase is limited, and the amount that can be purchased at one time is naturally limited. Also, storage space is limited in homes, workplaces, and public facilities.
From such a situation, toilet rolls in which the basis weight per toilet paper sheet is reduced to 14 g / m ² or less and the roll length is lengthened have been developed (Patent Documents 1 and 2).
In addition, the applicant of the present application has developed a toilet roll having a longer roll length while improving the feel and usability by increasing the basis weight per toilet paper to more than 13 g / m ² (Patent Document 3).

JP 2006-087703 A JP 2013-208297 A JP 2014-188342 A

However, when the basis weight of the paper is reduced, the strength and the feeling of use and the bulkiness are reduced. On the other hand, if the calendering is weakened in order to increase the bulk of the paper to compensate for these problems, there is a problem that the smoothness is poor or the roll diameter is large, making it difficult to fit in the toilet paper holder.
Further, in order to increase the winding length of the toilet roll and not to increase the winding diameter so as not to hinder the mounting on the paper holder, it is necessary to wind the roll firmly. However, in this case, there is a problem that an excessive pressure is applied particularly to the inner-wrapped toilet paper, and the emboss provided on the inner-wrapped toilet paper is crushed, resulting in poor aesthetics during use.
Accordingly, the present invention provides a toilet roll that is excellent in sheet softness without decreasing the basis weight, lengthens the winding length per roll, and maintains the aesthetics by embossing and is excellent in space saving during carrying and storage. The purpose is to provide.

The present inventors have found that, in order to improve the softness and aesthetics of the toilet paper sheet, when embossing is applied to improve the degree of unevenness, while increasing the winding length of the toilet roll, the winding diameter is increased. It has been found that the difference between the embossing depth of the outer winding and the inner winding of the roll needs to be within a predetermined range in order to prevent the diameter from becoming large.
In other words, if the roll is too tightly wound, excessive pressure is applied to the inner-wrapped toilet paper, the embossing provided on the inner-wrapped toilet paper is crushed, and the aesthetics deteriorate when the inner roll is used. On the other hand, if the roll is wound too weakly, the emboss will not be crushed, but the winding diameter will be large and it will be difficult to attach to the paper holder, or the winding force of the inner winding will be too weak, as shown in FIG. Is protruded in the axial direction, resulting in a defective product.

In order to solve the above-mentioned problem, the toilet roll of the present invention is a toilet roll in which toilet paper rolled up in two plies and single embossed toilet paper is rolled, and each ply is made of kraft pulp. １００100% by mass, winding length is 70 to 85m, winding diameter is 111 to 123mm, winding density is 1.43 to 1.77m / cm ² , emboss depth D1 is 0.11 to 0.35mm, emboss depth is D2 is 0.08 to 0.30 mm, embossed area 2.5~6.0mm ^2, and D1> D2, the winding hardness is 0.4 to 1.1 mm. However, the embossing depth D1 is a depth of the embossing at a position corresponding to 10% of the winding length from the edge of the outermost winding when the toilet roll is unwound, and the embossing depth D2 is The emboss depth at a position corresponding to 90% of the winding length from the edge of the outermost winding.

It is preferred that the used paper pulp from Mi Rukukaton containing more than 60 wt% more than 0 mass%.
When a C light source defined by CIE (International Commission on Illumination) irradiates the surface side of the toilet paper with whiteness UV-in conforming to ISO 2470 and a filter that cuts ultraviolet light having a wavelength of 420 nm or less, It is preferable that a difference Δ from whiteness UV-cut based on ISO 2470 when the C light source is irradiated on the surface side of the toilet paper is 0.0 to 2.5 points.

  ADVANTAGE OF THE INVENTION According to this invention, the toilet which is excellent in the softness of a sheet | seat, does not reduce a basis weight, lengthens the winding length per roll, and is excellent in space saving at the time of carrying and storage while maintaining the aesthetics by embossing. You can get a roll.

It is a perspective view showing the appearance of the toilet roll concerning an embodiment of the present invention. It is sectional drawing which shows the emboss provided on the roll front surface and back surface. It is a figure showing an example of a roll winding machine. It is a figure showing a measuring method of emboss depth. It is another figure which shows the measuring method of an emboss depth. It is a figure following FIG. It is a figure showing an example of a machine winder. FIG. 4 is a diagram showing a photographed image of an embossed concave portion on the roll surface side. It is a figure showing the method of measuring emboss depth D1 and D2. It is another figure which shows the method of measuring emboss depth D1, D2. It is a figure which shows the defective article which the inner winding side of the roll protruded in the axial direction.

Hereinafter, preferred embodiments of the present invention will be described, but these are provided for illustrative purposes and do not limit the present invention.
As shown in FIG. 1, a toilet roll 10 according to an embodiment of the present invention is a toilet roll obtained by winding a toilet paper 10x that has been superimposed on two plies and has been embossed into a roll, and has a winding length (winding length). The take-up length) is 63 to 103 m, the winding diameter DR (outer diameter of the roll) is 105 to 134 mm, the winding density is 1.2 to 2.0 m / cm ² , and the emboss depth D1 (mm) and the emboss depth D2 (Mm) ratio {(D2 / D1) × 100} is 45 to 100%.
The outer surface of the roll of the toilet paper 10x is the roll surface (or the surface of the toilet paper) 10a, and the inner surface of the roll is the back surface of the roll (or the back surface of the toilet paper) 10b.
As a method of adjusting the winding density of the toilet roll and the hardness of the toilet roll to be in the above range, the strength of winding the roll with a roll winder (especially a surface type) while adjusting the basis weight and the paper thickness to a predetermined range. There is a way to do it.

If the roll length of the toilet roll 10 is less than 63 m, the roll length per roll becomes short, and space saving during storage cannot be achieved. When the roll length exceeds 103 m, the roll diameter DR exceeds 134 mm, making it difficult to fit in a toilet paper holder or the like.
The winding length is preferably 70 to 85 m, more preferably 73 to 78 m.

When the winding diameter DR is less than 105 mm, the winding length is also reduced to less than 63 m. If the winding diameter DR exceeds 134 mm, it becomes difficult to fit in a toilet paper holder or the like.
The winding diameter DR is preferably from 108 to 125 mm, more preferably from 113 to 119 mm.

As described above, when the roll is too tightly wound, an excessive pressure is applied to the inner-wrapped toilet paper, and the emboss provided on the inner-wrapped toilet paper is crushed, and the cosmetic property is reduced during use. On the other hand, if the roll is wound too weakly, the emboss will not be crushed, but the winding diameter will be large and it will be difficult to attach it to the paper holder, or the winding force of the inner winding will be too weak, and the inner winding side of the roll will be in the axial direction. Defective products occur. For this reason, the winding density is defined as a factor for expressing the winding strength of the roll.
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 roll outer diameter (winding diameter DR) portion}-(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.
If the winding density is less than 1.2 m / cm ² , the winding diameter DR will exceed 134 mm, making it difficult to fit in a toilet paper holder or the like, and the winding force of the inner winding will be too weak, and the inner winding side of the roll will It protrudes in the axial direction (poor shape retention of the roll), resulting in a defective product. When the winding density exceeds 2.0 m / cm ² , the softness of the sheet is inferior, the embossing provided on the toilet paper is crushed, and the cosmetic property is reduced during use.
The winding density is preferably from 1.4 to 1.8 m / cm ² , more preferably from 1.5 to 1.7 m / cm ² .

When the basis weight per sheet of the toilet paper 10x is more than 13 g / m ² and not more than 17 g / m ² and the paper thickness is more than 0.6 mm / 10 and not more than 1.1 mm / 10, the roll hardness is increased. , The winding length, the winding diameter DR, and the winding density are preferable because they can be easily adjusted to the above ranges.
Methods for adjusting the basis weight and paper thickness of the toilet paper 10x per sheet to the above ranges include calender conditions (paper thickness and specific volume after calendering, paper thickness difference before and after calendering) and embossing conditions of the base paper web. Is defined.

When the basis weight per sheet of the toilet paper 10x is 13 g / m ² or less, or the paper thickness is 0.6 mm / 10 or less, the strength is reduced and the feeling of use (bulk height) is also reduced. There are cases. When the basis weight per one piece of the toilet paper 10x exceeds 17 g / m ² , or when the paper thickness exceeds 1.1 mm / 10 sheets, the toilet paper becomes thick, and the roll diameter DR of a roll formed by winding the toilet paper 63 m or more. May exceed 134 mm, making it difficult to fit in the toilet paper holder.
The basis weight per sheet of the toilet paper 10x is more preferably 13.5 to 16.5 g / m ² , and still more preferably 14.1 to 16.0 g / m ² . The paper thickness of the toilet paper 10x is more preferably 0.65 to 0.90 mm / 10, and still more preferably 0.71 to 0.83 mm / 10.

<Emboss>
The toilet roll 10 (toilet paper 10x) of the present invention is embossed. In particular, single embossing is preferred.
As shown in FIG. 3, the single emboss is formed by pressing the embossed convex portion of the emboss roll 151 only from one surface of the toilet paper 10x in which the sheets are stacked in two plies.
FIG. 2 is a sectional view showing the single emboss 2 provided on the toilet roll 10 (toilet paper 10x). In the example of FIG. 2, the toilet paper 10x is formed by stacking sheets in two plies, and the upper part of FIG. 2 corresponds to the roll surface 10a side. An emboss (single emboss) 2 is formed on the surface (the front surface in FIG. 2) of the toilet paper 10x against which the emboss roll 151 is pressed, where the concave portion 2R and the convex portion 2P appear on the back surface.
FIG. 2A shows the case where the emboss depth is deep, and FIG. 2B shows the case where the emboss depth is shallow.

In this case, the paper thickness t2 of the toilet paper 10x after the embossing process (this paper thickness reflects the distance between the non-embossed portion on the front surface of the toilet paper 10x and the embossed convex portion 2P on the back surface) is the same. However, the sheet obtained by embossing the sheet obtained by reducing the base paper to the paper thickness t1 by calendering so that the emboss depths D1 and D2 are deeper is softer and has a better texture. This is considered to be due to the fact that, in FIG. 2A, in which the embossment is conspicuous, the bulk of the base paper relative to the thickness of the base paper is higher (the density is lower), the base paper is easily deformed, and the softness of the sheet is improved. .
In the case of FIG. 2A, in order to increase the emboss depths D1 and D2, it is necessary to reduce the paper thickness t1 per sheet by that much to make the unevenness conspicuous. The softness of the sheet is improved due to strong calendering.
On the other hand, if the surface of the toilet paper 10x is made smooth without embossing, the surface is too smooth and crisp, and the softness of the sheet is inferior. In the toilet paper 10x, when the embossed recess 2R is provided on the outside of the roll (on the side of the roll surface 10a) where water easily adheres when using the warm water flush toilet seat, the recess 2R has a better tactile sensation than the projection. The softness of the sheet is improved.
FIG. 8 shows a photographed image of the embossed concave portion 2R on the roll surface 10a side.

In the case where double embossing is performed instead of the single embossing of FIG. 2, after embossing each sheet on the front side and the back side of the toilet paper 10x, ply-up is performed with the embossed convex surfaces of each sheet inside. To 2 plies. Therefore, the paper thickness t2 of the toilet paper 10x becomes too high, the winding density becomes low, and it may be difficult to secure the winding length. Even in the double embossing, if the embossing depths D1 and D2 are made shallow, the paper thickness t2 is reduced, but the softness of the sheet may be poor. Therefore, single embossing is preferred.
The means for ensuring the softness of the toilet paper (sheet) 10x is not limited to embossing as long as it imparts irregularities to the surface. For example, irregularities may be applied to the web during papermaking using an irregular fabric. Good. In this case, it is preferable that the depth of the unevenness is in a range corresponding to emboss depths D1 and D2 described later.

<Emboss depth D1, D2>
In the present invention, as a factor for expressing the winding strength of the roll, by defining the difference between the emboss depth of the outer winding and the inner winding of the roll, the emboss is not collapsed, and the winding diameter is not increased. I have. Specifically, the ratio {(D2 / D1) × 100} between the emboss depth D1 (mm) and the emboss depth D2 (mm) is set to 45 to 100%. The ratio is preferably 55 to 100%, more preferably 65 to 100%.
Here, as shown in FIG. 9, the embossing depth D1 is the embossing depth D1 of the embossing 2 at the position M1 corresponding to 10% of the winding length from the edge 10e of the outermost wound toilet paper when the toilet roll 10 is unwound. The emboss depth D2 is the depth of the recess 2R of the emboss 2 at the position M2 corresponding to 90% of the winding length from the edge 10e. For example, when the winding length is 75 m, the position M1 is a part 7.5 m from the edge 10 e. The specific method of measuring the emboss depths D1 and D2 will be described later.

  When the above ratio is less than 45%, the roll is too tightly wound and excessive pressure is applied to the inner-wrapped toilet paper, the emboss provided on the inner-wrapped toilet paper is crushed, and the balance of cosmetics during use is poor. When the above ratio is more than 100%, the roll is wound too weakly, the winding diameter becomes large and it becomes difficult to mount the roll on the paper holder, and the winding force of the inner winding becomes too weak, and the inner winding side of the roll becomes the shaft. It jumps out in the direction, resulting in a defective product.

The emboss depths D1 and D2 are determined by measuring the height difference of the emboss using a shape measuring laser microscope. The shape measuring laser microscope scans a laser light source, which is a point light source, through an objective lens into pixels obtained by dividing an XY plane in an observation field into a plurality of parts, and detects reflected light of each pixel with a light receiving element. . Then, the objective lens is driven in the height (Z-axis) direction, and the height information and the reflected light amount are detected with the Z-axis position having the highest reflected light amount as a focal point. By repeating scanning in this manner, a light quantity ultra-depth image and a high-low image (information) that are in focus on the whole are obtained. Since the laser light source is a pinhole confocal optical system, the measurement accuracy is high.
As a shape measurement laser microscope, a product name “One-shot 3D measurement macroscope VR-3100” manufactured by KEYENCE can be used. The product name “VR-H1A” can be used as software for observing, measuring, and analyzing the image of the laser microscope. The measurement is performed under the conditions of a magnification of 12 times and a visual field area of 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.

  First, as shown in FIG. 4, the longest part a of the peripheral edge fr of the emboss is determined. FIG. 5A shows a height profile on an XY plane by a shape measuring laser microscope, and it can be seen that the height of the toilet paper surface is represented by shading. 5 (a) shows the individual embossments 2, and the longest part a of one emboss 2 can be distinguished from FIG. 5 (a). When a line segment AB crossing the longest portion a is drawn, a height (measurement section curve) profile of the emboss 2 is obtained as shown in FIG. 5B. Here, the embossed portion (non-embossed portion) and the concave portion can be recognized from the shading of the color of the XY plane image, and therefore the line segment AB is determined so as to cross the portion where the convex portion and the concave portion are adjacent to each other. Just fine.

Here, the height profile in FIG. 5B is a (measurement) cross-sectional curve S representing the unevenness of the actual toilet paper sample surface. (A steep peak caused by a whisker-like extension or a fiber-free portion), and it is necessary to remove such a noise peak in calculating the height difference of the unevenness.
Therefore, as shown in FIG. 6, a “contour curve” W is calculated from the cross-sectional curve S of the height profile, and two maximum curvature points P1, which are convex upward toward the inside of the emboss , of the contour curve W. The minimum value sandwiched between P2 and the curvature maximum points P1 and P2 is determined, and is set as the minimum value Min of the depth. Further, the average value of the depth values of the curvature maximum points P1 and P2 is defined as the maximum value Max of the depth.
In this way, the emboss depth D1 (similarly for D2) = maximum value Max−minimum value Min. The distance (length) of the curvature maximum points P1 and P2 on the XY plane is defined as the length of the longest part a. Note that the “contour curve” has a wavelength shorter than λc: 800 μm (where λc is a “filter that defines the boundary between the roughness component and the undulation component” described in JIS-B0601 “3.1.1.2”) from the cross-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 more than the interval between adjacent embosses P1 (this is referred to as emboss pitch), the peak may be recognized as noise, so λc is set to be less than the emboss pitch. For example, when the emboss pitch is 800 μm or less, for example, λc is set to 250 μm. The interval of P1 between the adjacent embosses is the same as that of P1 and P2 for the next emboss connected to the left or right in FIG. 6, and the interval between two P1s when the adjacent embosses are lined up with P1, P2, and P1. is there.

Similarly, in FIG. 5A, the emboss depths D1 and D2 of the longest portion b in the direction perpendicular to the longest portion a are measured, and among the emboss depths D1 and D2 of the longest portions a and b, The larger value is adopted as the emboss depths D1 and D2. The above measurement is performed for any ten embosses 2 on the surface 10a of the toilet paper 10x, and the average value is adopted as final emboss depths D1 and D2.
The product (a × b) of the longest part a and the longest part b is obtained as the area S of the emboss 2. As the longest part a and the longest part b, values obtained by averaging the respective values of a and b for the ten embosses 2 on the surface 10a of the toilet paper 10x described above are used.
The emboss area S is preferably 0.4 to 7.0 mm ² , more preferably 1.5 to 6.5 mm ² , still more preferably 2.5 to 6.0 mm ² , and most preferably 3.5 to 5.5 mm ² . ² . If the emboss area S is less than 0.4 mm ² , the emboss may be too small and the cosmetic may be inferior. On the other hand, if the emboss area S exceeds 7.0 mm ² , the emboss may be too large, and similarly the cosmetic may be inferior.

When measuring the emboss depths D1 and D2, the measurement surface is the surface 10a side regardless of whether it is single emboss or double emboss.
In addition, when obtaining the emboss depths D1 and D2 and the emboss area S, selecting any ten embosses 2 is performed as shown in FIG. For example, when obtaining the emboss depth D1 and the emboss area S, any ten embosses are selected from the embosses 2 on the position M1 in FIG. At this time, the center of the emboss 2 does not need to pass through the position M1, and the emboss 2 at the position M1 may be put in the field of view of the above-mentioned laser microscope for shape measurement, and the longest portions a and b may be determined. The same applies to the emboss depth D2 at the position M2.
When there are less than 10 embosses 2 on the position M1, a group of outer winding side embosses 2F adjacent to the embossment 2 on the position M1 or an inner winding side adjacent to the embossing 2 on the position M1. An insufficient number of embosses may be selected from the group of embosses 2E. When the position M1 or M2 corresponds to the perforation, the measurement is performed on the group of the embossment 2 on the outer winding side adjacent to the perforation.

The emboss depth D1 is preferably 0.05 to 0.40 mm, more preferably 0.09 to 0.35 mm, and still more preferably 0.13 to 0.30 mm. The emboss depth D2 is preferably 0.05 to 0.35 mm, more preferably 0.09 to 0.32 mm, and still more preferably 0.13 to 0.29 mm.
If the embossing depths D1 and D2 are smaller than the above ranges, the degree of embossing unevenness becomes small, the bulk becomes low (the density becomes high), and it may be difficult to improve the softness of the sheet. If the embossing depths D1 and D2 exceed the above ranges, the embossment becomes too conspicuous, the bulk becomes too high (the density becomes too low), the winding diameter DR exceeds 134 mm, and the toilet roll is attached to the paper holder. 10 may be difficult to wear.

FIG. 3 shows an example of the roll winding machine 150. The stencil roll is preliminarily formed into two plies by a ply machine and calendered, and becomes a web 4 (sheet thickness t1 of each sheet). The web 4 is set on a roll winder 150, is subjected to a single embossing process by an embossing unit (embossing roll) 151, and is wound by a winding mechanism 153 around a wide toilet paper roll 10W having the above winding diameter. Taken. Thereafter, the original roll 10W is cut into a predetermined width (114 mm or the like) to form the toilet roll 10.
The roll winding machine 150 is roughly classified into a surface type and a center type. The surface method is a method in which the roll to be wound is wound while being supported from outside by a plurality of other drive rolls, and the wound roll of the wound toilet roll 10 is easily controlled, and the production speed becomes higher. The center method is a method of winding by driving a shaft passing through the center of a winding roll. The wound toilet roll 10 is a relatively soft product, and is suitable for a product having a delicate emboss. In the present invention, the film can be wound by any method, but a surface method is preferable.
In addition, the machine winder 100 may be incorporated in the roll winding machine 150, and ply-up, calendering, and embossing may be performed in this order by the roll winding machine. Alternatively, one sheet of sanitary thin paper may be plied up after calendering and embossed.

The emboss depths D1 and D2 can be controlled by appropriately adjusting the nip width of the rubber roll (see FIG. 3) facing the emboss roll 151. The nip width varies depending on the characteristics of the roll, but is preferably 20 to 45 mm, more preferably 25 to 42 mm, and still more preferably 30 to 39 mm. If the nip width exceeds 45 mm, the emboss becomes too strong and the front-back difference increases, or the paper thickness increases and the roll diameter DR of the roll increases. On the other hand, if the nip width is less than 20 mm, the emboss may be weak and the softness of the sheet 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 carbon paper and ordinary copy paper are set one on top of the other. Next, a nip is applied to the embossing roll. After that, release the nip and remove the carbon paper and copy paper. Since the color of the carbon paper at the portion where the nip is applied by the embossing roll is transferred to the copy paper, the nip width can be measured.
The embossing depths D1 and D2 can be adjusted by narrowing the nip width when the embossing roll has deep irregularities, and increasing the nip width when the embossing roll has shallow irregularities.

  Printing, embossing, perforation, tail sealing, and cutting of a predetermined width (114 mm or the like) can be simultaneously performed by the roll winding machine, and the toilet roll 10 can be manufactured. Further, after that, film packaging processing can be performed to manufacture a toilet roll package.

The roll hardness of the toilet roll 10 is preferably 0.3 to 1.4 mm, more preferably 0.4 to 1.2 mm, and most preferably 0.5 to 0.9 mm.
When the roll hardness is less than 0.3 mm, the roll is too tightly wound, and the emboss of the inner roll toilet paper is crushed, and the ratio {(D2 / D1) × 100} is less than 45%, resulting in inferior cosmetics during use. In addition, the softness of the roll may be inferior.
On the other hand, if the roll hardness exceeds 1.4 mm, the roll becomes too soft and may be crushed after being packaged with the toilet roll 10 in a film, or the roll diameter DR of the roll may be too large to fit in a toilet paper holder or the like. There is. Further, the winding force of the inner winding becomes too weak, and the inner winding side of the roll may protrude in the axial direction to cause a defective product.
Here, the softness of the roll is a tactile sensation when the user holds the toilet roll in a shop, and does not directly reflect the softness of the sheet. However, it is not possible to check the softness of the sheet by unwinding the roll at the store, and if the roll itself is hard even if the sheet itself is soft, the sheet is considered to be hard, and purchase cannot be encouraged. For this reason, the sales promotion effect can be enhanced by improving the softness of the roll.

The hardness of the toilet roll 10 is measured as follows using a compression tester (KES-G5, a handy compression tester manufactured by Kato Tech Co., Ltd.). First, the toilet roll 10 is placed sideways on a hard table so that the axis is horizontal. Next, the above-mentioned KES-G5 compressor (area of 2.0 cm ² ) is pressed into the center of the roll surface of the toilet roll 10 from above at a speed of 10 mm / min. Asshukuko is the indentation depth when the pressure pushing the rolls of 0.5gf / cm ² T0, the indentation depth when the pressure of 50 gf / cm ² as Tm, and Makikata of the (Tm-T0). The measurement is performed five times, and the measurement results are averaged.

It is preferable that the specific volume of the toilet paper is 4.0 to 6.5 cm ³ / g.
If the specific volume is less than 4.0 cm ³ / g, the softness of the sheet may be poor, or the bulk (bulk) may be reduced, resulting in poor water absorption. On the other hand, when the specific volume exceeds 6.5 cm ³ / g, the bulk (bulk) of the sheet increases, but the paper thickness after embossing increases and the winding diameter may increase. The specific volume is preferably from 4.3 to 6.1 cm ³ / g, more preferably from 4.7 to 5.6 cm ³ / g.

According to JIS P8113, the longitudinal tensile strength of toilet paper (two-ply sheet) when dry is DMDT (Dry Machine Direction Tensile strength), and the transverse tensile strength when dry is DCDT (Dry Cross Direction Tensile strength). ), DMDT is preferably 2.2 to 5.0 N / 25 mm, more preferably 2.5 to 4.5 N / 25 mm, even more preferably 2.7 to 4.0 N / 25 mm, and DCDT is preferably 0. It is 0.8 to 2.2 N / 25 mm, more preferably 0.9 to 1.9 N / 25 mm, and still more preferably 1.0 to 1.6 N / 25 mm.
If the DMDT and DCDT are less than the above values, they may be easily broken and may not be suitable for practical use. When DMDT and DCDT are higher than the above values, the sheet becomes hard, and the softness of the sheet may be impaired.
In addition, the flow direction of the papermaking of the toilet paper is referred to as “vertical direction”, and the direction perpendicular to the flow direction is referred to as “lateral direction”.

The water absorption of the toilet paper (two sheets) based on the old JIS S3104 is preferably 7.0 seconds or less, more preferably 5.0 seconds or less, and even more preferably 3.0 seconds or less. The higher the water absorption, the better. However, if it exceeds the above range, the water absorption may be poor.
The ease of loosening based on JIS-P4501 when the toilet paper is peeled into one sheet is preferably 60 seconds or less, more preferably 50 seconds or less, and even more preferably 40 seconds or less. The ease of loosening is better if it is faster, but if it exceeds the above range, the water disintegration in the toilet may be poor.

The toilet paper may be composed of 100% by weight of wood pulp, and may include waste paper pulp, non-wood pulp, and deinked pulp. In order to obtain the target quality, the content of NBKP (softwood bleached kraft pulp) is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, and still more preferably 5 to 15% by mass. The content of LBKP (hardwood bleached kraft pulp) is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, and still more preferably 50 to 70% by mass.
The content of waste paper pulp derived from a milk carton (milk pack) is preferably 0 to 60% by mass, more preferably 10 to 50% by mass, and still more preferably 20 to 40% by mass. , Preferably 40 to 100% by mass, more preferably 50 to 90% by mass, and still more preferably 60 to 80% by mass.
Recycled paper pulp derived from milk cartons (milk packs) is mainly made of softwood pulp, and has the advantage of easily securing the strength of toilet paper. On the other hand, there is a large variation in quality, and if the content ratio is too high, the quality of the product will be affected. The content is preferably in the above range.
Pulp produced from Eucalyptus genus, such as Eucalyptus grandis and Eucalyptus globulus, as a material of the LBKP is preferable.

In addition, 25 parts by mass or less of deinked pulp derived from used newspaper or magazine paper can be blended with 100 parts by mass of the waste paper pulp derived from NBKP, LBKP or milk carton. The content of the deinked pulp in the toilet paper (sheet) when 25 parts by mass of the deinked pulp is blended is 25 parts by mass / (100 parts by mass + 25 parts by mass) × 100 = 20% by mass. The content of the deinked pulp is 0 to 20% by mass, preferably 0 to 10% by mass, more preferably 0 to 5% by mass or less, and most preferably 0% by mass. Since deinked pulp is also used paper, the quality varies greatly. Further, the deinked pulp usually contains a fluorescent dye, and if its content exceeds 20% by mass, it contains a large amount of the fluorescent dye, which is not preferable.
When the deinked pulp contains a fluorescent dye, the difference Δ between the whiteness value of the toilet paper (sheet) under the UV-in condition and the whiteness value under the UV-cut condition increases. Here, the UV-in is a whiteness conforming to ISO 2470 when a C light source (including ultraviolet light) specified by the CIE (International Commission on Illumination) is applied to the sheet surface side. UV-cut is whiteness in conformity with ISO 2470 when the C light source is irradiated on the sheet surface side through a filter that cuts ultraviolet light having a wavelength of 420 nm or less. The difference Δ = (whiteness UV-in) − (whiteness UV-cut).
The difference Δ is preferably 0.0 to 2.5 points, more preferably 0.0 to 1.5 points, still more preferably 0.0 to 1.0 points, and most preferably 0.0 to 0.5 points. It is. The whiteness can be measured using a high-speed spectrophotometer CMS-35SPX manufactured by Murakami Color Research Laboratory Co., Ltd. in accordance with ISO 2470.

  In addition, in order to secure appropriate strength to the toilet paper, the raw materials can be blended by ordinary means, and the strength can be adjusted by beating pulp fibers. As the beating to obtain the target quality, commercially available virgin pulp is filtered at a Canadian standard freeness of 0 to 150 ml, more preferably 0 to 100 ml, still more preferably 10 to 50 ml, as measured by JIS-P8121. Reduce water content. Also, it is preferable not to use a wet paper strength enhancer.

Toilet paper can be made by mixing a softwood kraft pulp and a hardwood kraft pulp having a certain range of fiber length and fiber roughness in a specific range when a virgin raw material is used for the stock. 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, and absorbents can be used as additives to the stock. An enhancer or the like can be used.
The same processing as in the case of the above-mentioned virgin system is performed also when the used paper material is used as the toilet paper.
Details of the method of manufacturing the toilet paper will be described later.

  Toilet paper can be manufactured in the order of (1) papermaking and creping, (2) ply-up and calendering by a machine winder, and (3) embossing and roll winding as follows, for example. Of these, (3) has already been described and will not be described.

(1) papermaking and creping,
First, a web is made from the above stock on a wire part of a known paper machine, and is moved to a felt of a press part. Examples of the wire part type include a round net type, a long net (Ford Linear) type, a suction breast type, a short net type, a twin wire type, a crescent former type, and the like.
Then, the web is mechanically compressed by a suction pressure roll, a pressure roll or a press roll without suction, or dehydration is continued by a dehydration method such as through-flow drying with hot air. Further, a suction pressure roll or a pressure roll without suction is also used as a means for moving the web from the press part to the Yankee dryer.

The web transferred to the Yankee dryer is dried by a Yankee dryer and a Yankee dryer hood, creped by a creping doctor, and wound up by a reel part.
Creping (creping of wavy wrinkles, called crepe) is the mechanical compression of paper in the machine direction (in the direction of sheet travel on a paper machine). When the web of toilet paper is manufactured, the web on the Yankee dryer is peeled off by the creping doctor and wound up by 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) ) Forms crepes (wrinkles) in the creping doctor.
The quality required for the toilet paper, that is, bulk (bulk feeling), softness, water absorption, surface smoothness, appearance (crepe shape), and the like are influenced by the speed difference. Although depending on the conditions such as the speed difference, the basis weight of the web on the reel after creping is approximately 14 to 20 g / m ² , which is heavier than the basis weight of the web on the Yankee dryer before creping. The basis weight is preferably 14 to 18 g / m ² . If it exceeds the above range, the strength may be increased and the paper may be rough, and if it is less than the above range, the strength may be weak and the paper may be easily broken.

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 largely determined by the creping conditions, and the operating conditions for optimizing the creping conditions are important for those skilled in the art. In the present invention, the crepe ratio when producing toilet paper is preferably 10 to 50%, more preferably 15 to 40%, and most preferably 20 to 35%.

(2) Ply-up and calendar processing by machine winder FIG. 7 shows an example of the machine winder 100. As described above, two reels 1 wound by the reel part after creping are set in the machine winder 100, and are superposed and ply-up on two sheets so that the Yankee surface is on the outside. At this time, after the ply-up, the calendar processing is performed in two stages in the order of the calendar machine 101 of the first stack and the calendar machine 102 of the second stack. However, it is also possible to carry out calendar processing before ply-up or on-machine calendar.
The thickness of the toilet paper before embossing (after calendering) is preferably 0.55 to 1.15 mm / 10 sheets, and more preferably 0.60 to 0.80 mm / 10 sheets. Further, the specific volume of the toilet paper in the raw roll 4 before the embossing treatment (after the calendering treatment) is preferably 3.4 to 6.5 cm ³ / g, more preferably 3.7 to 6.0 cm ³ / g, and furthermore Preferably, it is 4.0 to 5.5 cm ³ / g.

Note that the paper thickness of the toilet paper before the embossing is the paper thickness of the raw roll 4 after the calendering in FIG. 7, and corresponds to the paper thickness t1 in FIG. However, as will be described later, the paper thickness is a value measured at a measurement load of 3.7 kPa, and thus does not accurately reflect the paper thickness t1 in FIG.
Also, the paper thickness of the embossed toilet paper shown in Tables 1 and 2 corresponds to the paper thickness t2 in FIG. 2, but is a value measured at a measurement load of 3.7 kPa, so that the paper thickness t2 is accurately reflected. It was not done.
On the other hand, the emboss depths D1 and D2 are measured in a state where the emboss is not compressed. Therefore, the emboss depths D1 and D2 are significantly larger than the values calculated from the paper thicknesses t1 and t2 (this value is a value obtained by compressing the emboss with a measured load of 3.7 kPa).

Each of the calenders 101 and 102 is preferably composed of two metal rolls. However, one of the two rolls may be an elastic roll so that soft calendering can be performed.
The linear pressure of the calender is preferably 3.0 to 8.0 kgf / cm, more preferably 4.0 to 7.0 kgf / cm. When the linear pressure exceeds the above range, the bulk becomes small and the softness may be inferior. Further, when the wire thickness is less than the above range, the bulk becomes large, and the roll diameter DR of the roll becomes large. Further, it is preferable that the linear pressure is higher in the second stack than in the first stack.
At the time of calendering, the draw can be adjusted appropriately. The draw between the reel 1 before the ply-up and the raw material 4 after the calender processing is preferably set to 100 to 110%.
By calendering and draw adjustment, the paper thickness can be controlled to exceed 0.6 mm / 10 sheets and 1.1 mm / 10 sheets or less while the basis weight is maintained at more than 13 g / m ² and 17 g / m ² or less.

It is preferable that the basis weight of the web of the raw material 4 after the calendering process and before the embossing process is 13.5 to 18.0 g / m ² per sheet. In the roll winding process described later, the web is slightly stretched and the basis weight is reduced. Therefore, the web is preferably set to 13.5 to 18.0 g / m ² , which is slightly higher than the target basis weight of the toilet roll 10 in the final form, and more preferably 14 to 15. 0.5 to 17.5 g / m ² . In addition, since the web is slightly stretched in the roll winding process, the paper thickness is reduced before and after the winding as well as the basis weight. However, the target paper thickness of the toilet roll 10 in the final form can be adjusted by embossing.

  The raw material 4 after the calendering process is embossed by, for example, a roll winding machine 150 in FIG. 3 to obtain the toilet roll 10. The winding hardness (and winding density) is determined by pressing the raw roll 10W from the outer peripheral side when the winding mechanism 153 winds up the wide toilet paper raw roll 10W in the roll winding machine 150. The pressing force of the rider roll 154 for sequentially winding the sheet can be adjusted by setting the pressing force within a predetermined range.

  The present invention is not limited to the above-described embodiments, but extends to various modifications and equivalents included in the spirit and scope of the present invention.

  The content of the pulp composition was (mass%) NBKP 10%, LBKP 60%, and wastepaper pulp 30%, and deinked pulp was not contained. The apparatus shown in FIGS. Toilet paper and toilet rolls were manufactured.

The following evaluation was performed.
Longitudinal tensile strength when dry DMDT and horizontal tensile strength when dry DCDT: The maximum load until breakage of toilet paper (two sheets) was measured in units of N / 25 mm based on JIS P8113.
Basis weight: Measured based on JIS P8124 and converted per sheet.
Paper thickness: Measured using a thickness gauge (a dial thickness gauge “PEACOCK” manufactured by Ozaki Seisakusho). The measurement conditions were as follows: the measurement load was 3.7 kPa, the probe diameter was 30 mm, the sample was placed between the probe and the measuring table, and the gauge was read when the probe was lowered at a speed of 1 mm or less per second. In addition, about the web before a calender process, it measures by stacking 10 sheets, and about the calender process (after a ply-up) and a roll, 5 sheets (5 sets) of toilet paper with a 2-ply sheet overlapped I went. 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 a sheet thickness per sheet.

Specific volume: The thickness per sheet was divided by the basis weight per sheet, and expressed as a volume cm ³ per unit g.
Roll diameter DR and core outer diameter DI: Measured using a Diameter rule manufactured by Muratec KDS Corporation. For the measurement, ten rolls were measured, and the measurement results were averaged.
The roll hardness, winding density, and emboss depths D1 and D2 were measured by the methods described above. In addition, the winding density of the roll measured ten rolls used for the measurement of the winding diameter DR of the roll, and averaged the measurement result.

The sensory evaluation was performed by 20 monitors. The evaluation criteria were based on a 5 point scale. If the evaluation criterion is 3 or more, it is good.
Incidentally, the measurement of the basis weight, tensile strength, thickness, specific volume, winding diameter DR, core outer diameter DI, winding hardness, winding density, and emboss depth were performed under the temperature and humidity conditions (23) specified in JIS-P8111. (± 1 ° C., 50 ± 2% RH).

  Tables 1 and 2 show the obtained results.

  As is clear from Tables 1 and 2, in each of the examples in which the roll length, the roll diameter, the roll density, and the ratio (D2 / D1) of the toilet roll are within a predetermined range, the sheet weight is not reduced without reducing the basis weight. While improving the softness, the beauty by embossing was maintained, and the winding length per roll could be increased.

On the other hand, although the softness of the sheet was excellent by imparting an embossment of an appropriate depth, in the case of Comparative Example 1 in which the winding length was less than 63 m, the winding diameter was less than 105 mm, and the roll replacement frequency was increased. .
Although the softness of the sheet was excellent by giving an emboss of an appropriate depth, in the case of Comparative Example 2 in which the winding length exceeded 105 m, the winding diameter exceeded 134 mm, and the roll diameter became large, and the toilet paper holder was used. It became difficult to fit.
In the case of Comparative Example 3 in which the winding hardness was less than 0.3 mm and the winding diameter was less than 105 mm, the softness of the roll was inferior. In addition, since the emboss depths D1 and D2 were both less than 0.05 mm, the degree of embossing unevenness was reduced, the bulk was reduced (density was reduced), and the sheet was inferior in softness.

  In the case of Comparative Example 4 in which the roll hardness exceeded 1.4 mm, the roll diameter exceeded 134 mm, and the roll diameter increased, making it difficult to fit in the toilet paper holder. Further, the embossing depths D1 and D2 exceed 0.40 mm and 0.35 mm, respectively, and the embossed irregularities are too remarkable and the bulk is too high (density is too low). Probably exceeded.

  In the case of Comparative Example 5 in which the toilet paper was rolled too weakly (softly) with a roll winder and the stiffness exceeded 1.4 mm, the roll diameter of the toilet roll exceeded 134 mm, and the roll diameter increased to fit in the toilet paper holder. It became difficult.

In the case of Comparative Example 6 in which the toilet paper was too weakly (softly) wound with a roll winder and the stiffness exceeded 1.4 mm, and the ratio (D2 / D1) exceeded 100%, the diameter of the toilet roll was 134 mm. And the roll diameter became too large to fit in the toilet paper holder. Furthermore, since the ratio (D2 / D1) exceeded 100%, the winding force of the inner winding became too weak, and the inner winding side of the roll protruded in the axial direction, resulting in a defective product (see FIG. 11), and the shape retention of the roll. Inferior.
In the case of Comparative Example 7 in which the toilet paper was rolled too hard (hard) with a roll winder and the roll hardness was less than 0.3 mm, and the ratio (D2 / D1) was less than 45%, the roll diameter was less than 105 mm, Roll softness was poor. In addition, since the ratio (D2 / D1) was less than 45%, the embossing provided on the inner volume of toilet paper was crushed, and the balance of cosmetics during use was poor.

  In the case of Comparative Example 8 in which the winding length exceeded 105 m and the winding diameter exceeded 134 mm, the roll diameter was large and it was difficult to fit in the toilet paper holder. In addition, the emboss depths D1 and D2 were each less than 0.05 mm, the degree of embossment unevenness was reduced, the bulk was reduced (density was reduced), and the sheet was inferior in softness.

  In addition, when the commercially available products 1 to 3 were evaluated in the same manner, the roll length was less than 63 m in all cases, and the roll replacement frequency increased.

2 Emboss 10 Toilet roll 10e Edge of outermost roll of toilet paper 10x Toilet paper D1, D2 Emboss depth

Claims (3)

A toilet roll in which two-ply, single-embossed toilet paper is wound into a roll,
Each ply contains 40-100% by mass of kraft pulp,
The winding length is 70 to 85 m, the winding diameter is 111 to 123 mm, the winding density is 1.43 to 1.77 m / cm ² ,
An emboss depth D1 of 0.11 to 0.35 mm, an emboss depth D2 of 0.08 to 0.30 mm, an emboss area of 2.5 to 6.0 mm ² , and D1>D2;
A toilet roll having a roll hardness of 0.4 to 1.1 mm.
However, the emboss depth D1 is the depth of the emboss at a position corresponding to 10% of the winding length from the edge of the outermost toilet paper when the toilet roll is unwound, and D2 is the depth of the emboss at a position corresponding to 90% of the winding length from the edge. The toilet roll according to claim 1 , wherein the waste paper pulp derived from the milk carton contains more than 0% by mass and 60% by mass or less . When a C light source defined by CIE (International Commission on Illumination) irradiates the surface side of the toilet paper with whiteness UV-in conforming to ISO 2470 and a filter that cuts ultraviolet light having a wavelength of 420 nm or less, 3. The toilet roll according to claim 1 , wherein a difference Δ from whiteness UV-cut based on ISO 2470 when the C light source is irradiated on the surface side of the toilet paper is 0.0 to 2.5 points . 4.