JP6735308B2 - Toilet roll - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toilet roll obtained by rolling up a two-ply toilet paper.

The toilet paper is commercially available, which is mainly packaged in units of 4 rolls or 12 rolls. Since 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. In addition, storage space is limited at home, workplace, public facilities, etc.
Under these circumstances, toilet rolls have been developed in which the basis weight of each sheet of toilet paper is reduced to 14 g/m ² or less and the roll length is increased (Patent Documents 1 and 2).
Further, the applicant of the present application has developed a toilet roll having a long roll length while improving the texture and the feeling of use by making the basis weight of each toilet paper higher than 13 g/m ² (Patent Document 3).

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

However, when the basis weight of the paper is reduced, the strength is lowered and the usability and bulkiness are lowered. On the other hand, if the calendering process is weakened in order to increase the bulk of the paper in order to compensate for these problems, there is a problem in that the smoothness becomes poor and the roll diameter becomes large, making it difficult to fit in the toilet paper holder.
Further, the technique described in Patent Document 3 improves the texture while increasing the basis weight of the toilet paper, but the softness of the roll has not been examined.
Here, the softness of the roll is the tactile sensation of holding the toilet roll in the store, and does not directly reflect the softness of the sheet. However, since it is not possible to unroll the roll at the store to check the softness of the sheet, even if the sheet itself is soft, if the roll is hard, the sheet seems to be hard, and it is not possible to encourage purchase. There is.
Accordingly, the present invention provides a toilet roll which is excellent in the softness of the sheet and roll without lowering the grammage, increases the winding length per roll, enhances the sales promotion effect, and is excellent in space saving during carrying and storage. With the goal.

The present inventors have improved the softness of the sheet of toilet paper by, for example, embossing it into an appropriate uneven shape to further secure the softness and winding length of the roll. Focused on the density.
That is, even if embossing or the like is applied to soften the sheet, if the roll is wound too tightly, the softness of the roll decreases. On the other hand, if the roll is wound too weakly, the softness of the roll is improved, but the roll diameter is increased and the roll length is shortened.

In order to solve the above-mentioned problems, a toilet roll of the present invention is a two-ply toilet roll that has embossing and is wound up in a roll shape with toilet paper not coated with a chemical solution , and the embossing depth of the embossing is 0.05-0.40 mm , winding hardness 0.3-1.4 mm, winding length 70-85 m, winding diameter 105-134 mm, winding density 1.2-2.0 m/cm ² . The grammage per sheet of the toilet paper is more than 13 g/m ² and 17 g/m ² or less, and the tensile strength DMDT in the longitudinal direction of the toilet paper when dry as 2 plies is 2.5 to 2.5. It is 4.5 N/25 mm.

It is preferred before Symbol embossing is a single embossing.
The toilet paper preferably contains kraft pulp in an amount of 40 to 100% by mass.
It is preferable to contain waste paper pulp derived from a milk carton in an amount of more than 0 % by mass and 60 % by mass or less .
Through a whiteness UV-in conforming to ISO 2470 when a C light source specified by CIE (International Commission on Illumination) is applied to the surface side of the toilet paper, and a filter that cuts off ultraviolet light having a wavelength of 420 nm or less, The difference Δ from the whiteness UV-cut according to ISO 2470 when the surface of the toilet paper is irradiated with the C light source is preferably 0.0 to 2.5 points.

According to the present invention, a toilet roll which is excellent in sheet and roll softness without lowering the grammage, lengthens the roll length per roll, enhances the sales promotion effect, and is excellent in space saving during carrying and storage. Obtainable.

It is a perspective view showing appearance of a toilet roll concerning an embodiment of the present invention. It is sectional drawing which shows the embossing provided in the roll front surface and the back surface. It is a figure which shows an example of a roll winding processing machine. It is a figure which shows the measuring method of the embossing depth. It is another figure which shows the measuring method of the embossing depth. It is a figure following FIG. It is a figure which shows an example of a machine winder. It is a figure which shows the picked-up image of the embossing recessed part on the roll surface side.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described, but these are provided for the purpose of illustration 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 two-ply laminated toilet paper 10x into a roll shape and having a roll hardness of 0.3 to 1. 0.4 mm, the winding length (winding length) is 63 to 103 m, the winding diameter DR (outer diameter of the roll) is 105 to 134 mm, and the winding density is 1.2 to 2.0 m/cm ² .
The outer surface of the roll of the toilet paper 10x is a roll surface (or the surface of the toilet paper) 10a, and the inner surface of the roll is a roll back surface (or the back surface of the toilet paper) 10b.
As a method of adjusting the winding hardness and the winding density of the toilet roll within the above ranges, 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 a predetermined range is available. is there.

When the roll hardness of the toilet roll 10 is less than 0.3 mm, the softness of the roll is poor. On the other hand, when the roll hardness exceeds 1.4 mm, the roll becomes too soft and is crushed after packaging the toilet roll 10 with a film, or the roll diameter DR of the roll becomes large and it is difficult to fit in a toilet paper holder or the like. The winding hardness is preferably 0.4 to 1.2 mm, more preferably 0.5 to 0.9 mm.
Here, even if embossing or the like is applied to soften the sheet, if the roll is wound too tightly, the softness of the roll decreases. On the other hand, if the roll is wound too weakly, the softness of the roll is improved, but the winding diameter DR is increased and the winding length is shortened. Therefore, the winding hardness and the winding density are defined as factors for achieving both the softness of the roll and the winding length.
The roll hardness of the toilet roll 10 is measured as follows using a compression tester (Handy compression tester KES-G5 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 KES-G5 compressor (area 2.0 cm ² ) is pushed 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 5 times, and the measurement results are averaged.

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. A roll having a roll length of more than 103 m has a roll diameter DR of more than 134 mm and is 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.

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

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.
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. When the winding density exceeds 2.0 m/cm ² , the softness of the sheet is poor or the softness of the roll is poor.
The winding density is preferably 1.4 to 1.8 m/cm ² , and more preferably 1.5 to 1.7 m/cm ² .

If the basis weight per sheet of toilet paper 10x exceeds 13 g/m ² and 17 g/m ² or less, and the paper thickness exceeds 0.6 mm/10 sheets and 1.1 mm/10 sheets or less, the roll hardness is , The winding length, the winding diameter DR, and the winding density are easily adjusted to the above ranges, which is preferable.
As a method of adjusting the basis weight and the paper thickness of the toilet paper 10x per sheet within the above range, the calender conditions (paper thickness and specific volume after calendering, difference in caliper before and after calendering) and embossing conditions of the base paper web are used. Stipulate.

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 sheets or less, the strength decreases and the usability (bulkness) also decreases. There are cases. When the basis weight per sheet of the toilet paper 10x exceeds 17 g/m ² or the paper thickness exceeds 1.1 mm/10 sheets, the toilet paper becomes thick and the winding diameter DR of the roll wound by 63 m or more. May exceed 134 mm, making it difficult to fit in the toilet paper holder.
The basis weight of each sheet of the toilet paper 10x is more preferably 13.5-16.5 g/m ² , and still more preferably 14.1-16.0 g/m ² . The thickness of the toilet paper 10x is more preferably 0.65 to 0.90 mm/10 sheets, further preferably 0.71 to 0.83 mm/10 sheets.

<emboss>
The toilet roll 10 (toilet paper 10x) of the present invention is preferably embossed with a depth of 0.05 to 0.40 mm. Single embossing is particularly preferable.
As shown in FIG. 3, the single embossing is formed by pressing the embossing convex portion of the embossing roll 151 only from one surface of the toilet paper 10x in which the sheets are stacked in two plies.
FIG. 2 is a cross-sectional view showing the single embossing 2 provided on the toilet roll 10 (toilet paper 10x). In the example of FIG. 2, the toilet paper 10x is made by stacking sheets in two plies, and the upper portion of FIG. 2 corresponds to the roll surface 10a side. The embossing (single embossing) 2 in which the concave portion 2R and the convex portion 2P appear on the back surface is formed on the surface (front surface in FIG. 2) of the toilet paper 10x against which the embossing roll 151 is pressed.
2A shows the case where the embossing depth is deep, and FIG. 2B shows the case where the embossing depth is shallow.

In this case, the paper thickness t2 of the toilet paper 10x after embossing is the same (this paper thickness reflects the distance between the non-embossed portion on the front surface of the toilet paper 10x and the convex portion 2P of the embossed surface on the back surface). However, the sheet in which the base paper is thinned to the paper thickness t1 by calendering and which is embossed so that the embossing depth D is deeper is softer and has a better texture. This is probably because the embossed unevenness shown in FIG. 2(a) has a higher bulk (lower density) with respect to the paper thickness of the base paper, is easily deformed, and improves the softness of the sheet. ..
Further, in the case of FIG. 2A, in order to increase the embossing depth D, it is necessary to reduce the paper thickness t1 per sheet to make the unevenness noticeable. The softness of the sheet is improved by virtue of strongly performing.
On the other hand, if the surface of the toilet paper 10x is made smooth without embossing, the surface is too smooth and the surface feels crispy, and the softness of the sheet is poor. In the toilet paper 10x, when the embossed recess 2R is provided on the outside of the roll (on the roll surface 10a side) where water is likely to adhere when using a warm water washing toilet seat, the recess 2R has a better tactile feel than the protrusion. The softness of the sheet is improved.
FIG. 8 shows a photographed image of the embossed recess 2R on the roll surface 10a side.

When double embossing is applied instead of the single embossing of FIG. 2, each sheet on the front and back sides of the toilet paper 10x is embossed, and then the embossed convex surfaces of each sheet are inwardly plied up. 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 with double embossing, if the embossing depth D is made shallow, the paper thickness t2 is reduced, but the softness of the sheet may be inferior. Therefore, single embossing is preferred.
Further, the means for ensuring the softness of the toilet paper (sheet) 10x is not limited to embossing as long as it gives unevenness to the surface, and for example, unevenness may be applied to the web at the time of paper making by using uneven fabric. Good. Further, in this case, the depth of the unevenness may be in a range corresponding to the embossing depth D described later.

<Embossing depth D>
The embossing depth D is preferably 0.05 to 0.40 mm, more preferably 0.09 to 0.35 mm, and further preferably 0.13 to 0.30 mm. When the embossing depth D is smaller than the above range, the degree of unevenness of the embossing is small and the bulk is low (density is high), and it may be difficult to improve the softness of the sheet. When the embossing depth D exceeds the above range, the embossing irregularities become too conspicuous and the bulk becomes too high (the density becomes too low), and the winding diameter DR exceeds 134 mm, and the toilet roll 10 is placed in the paper holder. It becomes difficult to wear.

The emboss depth D is obtained 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 visual field into a plurality of pixels, and detects reflected light of each pixel by 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 the focal point. By repeating the scan in this way, a light intensity super-depth image and a high-low image (information) that are entirely focused can be obtained. Since the laser light source is a pinhole confocal optical system, the measurement accuracy is high.
As the shape measuring laser 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 the software for observing, measuring, and analyzing images of the laser 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 field of view 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 embossed peripheral edge fr is obtained. FIG. 5A shows a height profile on the XY plane by the shape measuring laser microscope, and it can be seen that the height of the toilet paper surface is represented by shading. Dark portions in FIG. 5A indicate individual embosses 2, and the longest part a of one emboss 2 can be discriminated from FIG. 5A. By drawing a line segment AB crossing the longest part a, a height (measurement sectional curve) profile of the embossing 2 is obtained as shown in FIG. 5B. Here, since the convex portion (non-embossed portion) and the concave portion of the emboss can be known by the shade of the color of the XY plane image, the line segment AB can be determined so that the convex portion and the concave portion cross the adjacent portion. Good.

Here, the height profile in FIG. 5B is a (measurement) cross-section curve S that represents the unevenness of the sample surface of the actual toilet paper, but noise (there is a fiber lump on the surface of the toilet paper, fibers are It also includes a sharp peak due to a beard-like extension or a portion without fibers), and it is necessary to remove such a noise peak when calculating the height difference of the unevenness.
Therefore, as shown in FIG. 6, 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, the emboss depth D=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 the "filter that defines the boundary between the roughness component and the waviness component" described in JIS-B0601 "3.1.1.2") from the section 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 greater 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. 6, and the interval between the two P1 when the adjacent embosses are aligned with P1, P2, and P1. is there.

Similarly, in FIG. 5A, the emboss depth D is measured also for the longest part b in the direction perpendicular to the longest part a, and the larger value of the emboss depths D of the longest parts a and b is measured. Is adopted as the embossing depth D. The above measurement is performed for any 10 embossments 2 on the surface 10a of the toilet paper 10x, and the average value thereof is adopted as the final embossing depth D.
Further, the product (a×b) of the longest part a and the longest part b is obtained as the area S of the emboss 2. The longest part a and the longest part b use the value which averaged the value of each a and b about 10 embossing 2 of the surface 10a of the above-mentioned toilet paper 10x.
Embossed area S is preferably 0.4～7.0Mm ^2, more preferably 1.5～6.5Mm ^2, more preferably 2.5～6.0Mm ^2, and most preferably 3.5~5.5mm It is ² . When the embossed area S is less than 0.4 mm ² , the embossing may be too small and the cosmetic may be inferior. On the other hand, if the embossed area S exceeds 7.0 mm ² , the embossing may be too large, and similarly the cosmetic may be inferior.

When measuring the emboss depth D, the measurement surface is on the surface 10a side regardless of whether it is a single emboss or a double emboss.
Further, when selecting any 10 embosses 2 with the embossing depth D and the embossing area S, the toilet roll 10 is wound from the end of the outer roll of the toilet roll 10 (the position where the toilet paper starts to be used). It is measured at the portion corresponding to 20% of the length. For example, when the winding length is 75 m, the measurement is made at a part of 75 m×20%=15 m from the end. When 20% of the winding length hits the perforation, the outer winding side of the perforation is measured.

FIG. 3 shows an example of the roll winding machine 150. The base paper roll is preliminarily made into two plies by a ply machine and calendered to become a raw fabric 4 (paper thickness t1 of each sheet). The raw fabric 4 is set on the roll winding machine 150, subjected to single embossing by the embossing unit (embossing roll) 151, and then wound on the wide toilet paper raw roll 10W having the above winding diameter by the winding mechanism 153. Taken. Then, 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 two types, a surface type and a center type. The surface method is a method in which the winding roll is wound while being supported from the outside by a plurality of other driving rolls, and the wound roll of the wound toilet roll 10 is easy to control and the production speed becomes higher. The center system is a method of winding by driving a shaft passing through the center of the winding roll, and the wound toilet roll 10 is a relatively soft product and is suitable for a product with delicate embossing. In the present invention, the winding can be performed by any method, but the surface method is preferable.
Alternatively, the machine winder 100 may be incorporated in the roll winding machine 150, and the roll winding machine may perform ply-up, calendering, and embossing in this order. Alternatively, one sheet of sanitary thin paper may be calendered and then plied up and embossed.

The embossing depth D can be controlled by appropriately adjusting the nip width of the rubber roll (see FIG. 3) facing the embossing 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 further preferably 30 to 39 mm. When the nip width exceeds 45 mm, the embossing becomes too strong and the difference between the front and back becomes large, or the paper thickness becomes high and the winding diameter DR of the roll becomes large. On the other hand, when the nip width is less than 20 mm, embossing may be weakened and the sheet may be inferior in softness. 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 was applied by the embossing roll is transferred to the copy paper, the nip width can be measured.
Note that the embossing depth D can be adjusted by narrowing the nip width if the embossing roll has unevenness deep, and widening the nip width if the embossing roll has shallow unevenness.

Printing, embossing, perforation processing, tail sealing, and cutting with a predetermined width (114 mm, etc.) can be performed at the same time with a roll winding machine, and the toilet roll 10 can be manufactured. Further, thereafter, film packaging processing can be performed to manufacture a toilet roll package.

The specific volume of the toilet paper is preferably 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 (bulkness) may be reduced, resulting in poor moisture absorption. On the other hand, if the specific volume exceeds 6.5 cm ³ /g, the bulk (bulkness) of the sheet increases, but the paper thickness after embossing may increase and the winding diameter may increase. The specific volume is preferably 4.3 to 6.1 cm ³ /g, more preferably 4.7 to 5.6 cm ³ /g.

DMDT (Dry Machine Direction Tensile strength) is the longitudinal tensile strength of the toilet paper (double-layered sheet) based on JIS P8113 when dry, and DCDT (Dry Cross Direction Tensile strength) is the lateral tensile strength when dry. ), DMDT is preferably 2.2 to 5.0 N/25 mm, more preferably 2.5 to 4.5 N/25 mm, still more preferably 2.7 to 4.0 N/25 mm, and DCDT is preferably 0. It is 0.80 to 2.2 N/25 mm, more preferably 0.9 to 1.9 N/25 mm, and further preferably 1.0 to 1.6 N/25 mm.
If DMDT and DCDT are less than the above values, they may be easily shaken and not 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.
The flow direction of the toilet paper is defined as "longitudinal direction" and the direction perpendicular to the flow direction is defined as "transverse direction".

The water absorption of toilet paper (double-layered sheet) based on old JIS S3104 is preferably 7.0 seconds or less, more preferably 5.0 seconds or less, and further preferably 3.0 seconds or less. The higher the water absorption, the better, but if it exceeds the above range, the water absorption may be poor.
The easiness of loosening based on JIS-P4501 when peeling off one piece of toilet paper is preferably 60 seconds or less, more preferably 50 seconds or less, and further preferably 40 seconds or less. The ease of loosening is better when it is fast, but if it exceeds the above range, water disintegration in the toilet may be poor.

The toilet paper may consist of 100% by weight of wood pulp, and may include waste paper pulp, non-wood pulp, and deinked pulp. To obtain the target quality, the content of NBKP (bleached softwood kraft pulp) is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, and further 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 further preferably 50 to 70% by mass.
Moreover, the content rate of the 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 further preferably 20 to 40% by mass. %, preferably 40 to 100% by mass, more preferably 50 to 90% by mass, and further preferably 60 to 80% by mass.
Waste paper pulp derived from milk carton (milk pack) is mainly composed of softwood pulp, which has the advantage of easily securing the strength of toilet paper, but on the other hand, there are large variations in quality, and if the content ratio is too high, the quality of the product will be affected. It is preferable that the content is within the above range.
Pulp manufactured from Eucalyptus genus Eucalyptus represented by Eucalyptus grandis and Eucalyptus globulus is preferable as the LBKP material.

In addition, 25 parts by mass or less of deinked pulp derived from newspapers, magazines, etc. can be added to 100 parts by mass of waste paper pulp derived from NBKP, LBKP and milk carton. The content of the deinking pulp in the toilet paper (sheet) when 25 parts by mass of the deinking pulp is mixed is 25 parts by mass/(100 parts by mass+25 parts by mass)×100=20% by mass. The content of 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 the deinked pulp is also used paper, the quality varies greatly. Deinked pulp usually contains a fluorescent dye, and if the content exceeds 20% by mass, a large amount of the fluorescent dye will be contained, 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 thereof under the UV-cut condition becomes large. Here, UV-in is a whiteness degree according to ISO 2470 when a C light source (including ultraviolet light) defined by CIE (International Commission on Illumination) is applied to the sheet surface side. UV-cut is a whiteness degree according to ISO 2470 when a C light source is irradiated on the sheet surface side through a filter that cuts off 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, further preferably 0.0 to 1.0 points, and most preferably 0.0 to 0.5 points. Is. The whiteness can be measured according to ISO 2470 using a high-speed spectrophotometer CMS-35SPX manufactured by Murakami Color Research Laboratory Co., Ltd.

In order to ensure proper strength in the toilet paper, it is possible to mix the raw materials by an ordinary means and adjust the strength by beating pulp fiber. As the beating to obtain the target quality, commercially available virgin pulp has a Canadian standard freeness measured by JIS-P8121 of 0 to 150 ml, more preferably 0 to 100 ml, still more preferably 10 to 50 ml. Reduce water level. It is also preferable not to use a wet strength agent.

In the case of using a virgin raw material for the stock, the toilet paper 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. As an additive to paper materials, depending on the quality required for the final product, softeners including debonder softeners, bulking agents, dyes, dispersants, dry paper strength enhancers, drainage improvers, pitch control agents, absorbency Improvers and the like can be used.
When using a waste paper material as toilet paper, the same treatment as in the case of the virgin type is performed.
Details of the method for manufacturing toilet paper will be described later.

The toilet paper can be manufactured, for example, in the following order: (1) papermaking and creping, (2) ply-up and calendering with a machine winder, (3) embossing and roll-winding. 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 the wire part of a known paper machine and moved to the felt of the 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 by a suction pressure roll or a pressure roll or a press roll without suction, 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.

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 toilet paper web is manufactured, the web on the Yankee dryer is peeled off by the creping doctor and wound up by the reel part. ) Forms a crepe (wrinkle) with a creping doctor.
The quality required for toilet paper, that is, bulkiness, softness, water absorption, surface smoothness, aesthetics (crepe shape), etc. is 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 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 high and the paper may be 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 largely 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 at the time of producing toilet paper is preferably 10 to 50%, more preferably 15 to 40%, 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 crepe are set on the machine winder 100, and the reels 1 are piled up and piled up so that the Yankee surface is on the outside, and the raw roll 4 is obtained. At this time, after the ply-up, the calendar machine 101 for the first stack and the calendar machine 102 for the second stack are subjected to calendar processing in two stages in this order. However, it is also possible to perform calendar processing before ply-up or on-machine calendar.
The paper thickness of the toilet paper before embossing (after calendaring) is preferably 0.55 to 1.15 mm/10 sheets, more preferably 0.60 to 0.80 mm/10 sheets. The specific volume of the toilet paper in the original fabric roll 4 before embossing (after calendaring) is preferably 3.4 to 6.5 cm3/g, more preferably 3.7 to 6.0 cm3/g, and further preferably It is set to 4.0 to 5.5 cm3/g.

The thickness of the toilet paper before embossing is the thickness of the original roll 4 after calendering in FIG. 7, and corresponds to the thickness t1 in FIG. However, as will be described later, the paper thickness is a value measured with a measuring load of 3.7 kPa, and thus does not accurately reflect the paper thickness t1 in FIG.
Further, the paper thickness of the toilet paper after embossing shown in Tables 1 and 2 corresponds to the paper thickness t2 of FIG. 2, but since it is the value measured under the measuring load of 3.7 kPa, the paper thickness t2 is accurately reflected. Not what I did.
On the other hand, the emboss depth D is a value measured in a state where the emboss is not compressed. Therefore, the emboss depth D is significantly larger than the value calculated from the paper thicknesses t1 and t2 (this value is the value obtained by compressing the emboss with the measurement load of 3.7 kPa).

Each of the calenders 101 and 102 preferably comprises two metal rolls, but 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 poor. Further, if the wire thickness is less than the above range, the bulk becomes large and the winding diameter DR of the roll becomes large. Further, it is preferable that the linear pressure of the second stack is higher than that of the first stack.
During the calendar process, the draw can be adjusted appropriately. The draw between the reel 1 before the ply-up and the raw material 4 after the calendering is preferably 100 to 110%.
By calendering and adjusting the draw, the paper weight can be controlled to exceed 0.6 mm/10 sheets and 1.1 mm/10 sheets or less while maintaining the basis weight to 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 fabric 4 after the calendering treatment and before the embossing treatment is 13.5 to 18.0 g/m ² per sheet. In the roll winding process described below, the web slightly expands and the basis weight becomes low. Therefore, it is preferably 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 0.5 to 17.5 g/m ² . Since the web is slightly stretched in the roll winding process, the paper thickness becomes low before and after the winding as well as the grammage, but the target paper thickness of the toilet roll 10 in the final form can be adjusted by embossing.

The calendered raw fabric 4 is embossed by, for example, the roll winding machine 150 shown in FIG. 3 to obtain the toilet roll 10.

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 content of pulp composition is (% by mass) NBKP 10%, LBKP 60%, milk carton-derived waste paper 30%, deinked pulp is not contained, and the apparatus shown in FIGS. Toilet paper and toilet rolls were manufactured.

The following evaluation was performed.
The maximum load until breaking was measured in units of N/25 mm for toilet paper (two sheets stacked) based on the tensile strength in dry direction DMDT and the tensile strength in dry direction DCDT: JIS P8113.
Basis weight: Measured based on JIS P8124 and converted per sheet.
Paper thickness: Measured using a thickness gauge (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 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. For the web before calendering, 10 sheets were stacked and measured. After calendering (after ply-up) and for the rolls, 5 sheets (5 sets) of 2 sheets of toilet paper were stacked. 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 the sheet thickness per sheet.

Specific volume: The thickness per sheet was divided by the basis weight per sheet, and expressed in volume cm ³ per unit g.
Roll 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 hardness, roll density, and emboss depth of the roll were measured by the methods described above.

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.
The basis weight, tensile strength, thickness, specific volume, winding hardness, winding density, and embossing depth are measured under the temperature and humidity conditions specified in JIS-P8111 (23±1°C, 50±2%RH ) Was used to hold the equilibrium state.

The obtained results are shown in Tables 1 and 2.

As is clear from Table 1 and Table 2, in the case of each example in which the roll hardness, roll length, roll diameter, and roll density of the toilet roll are within the predetermined ranges, the softness of the sheet and roll without lowering the basis weight. It was possible to lengthen the winding length per roll while improving both.

On the other hand, although the softness of the sheet was excellent by imparting an appropriate depth of embossing, 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 frequency of roll replacement was high. ..
Although the softness of the sheet was excellent by imparting an appropriate depth of embossing, 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, making it a toilet paper holder. It became difficult to fit.
In the case of Comparative Example 3 in which the embossing depth D is less than 0.05 mm and the winding hardness is less than 0.3 mm, the degree of unevenness of the embossing is small and the bulk is low (density is low), and the sheet and roll are soft. Was inferior.

In the case of Comparative Example 4 in which the embossing depth D was more than 0.40 mm and the winding hardness was more than 1.4 mm, the embossing irregularities were too conspicuous and the bulk was too high (the density was too low). The diameter exceeded 134 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 roll strength of the toilet paper was too weak (soft) and the roll hardness exceeded 1.4 mm, the toilet roll winding diameter 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 wound too strongly (hardly) with a roll winder and the winding hardness was less than 0.3 mm, the winding diameter was 105 mm, and the softness of the roll was poor.
In Comparative Example 7 in which the emboss depth D was less than 0.05 mm, the degree of unevenness of the emboss was small, the bulk was low (the density was low), and the softness of the sheet was poor. Further, in the case of Comparative Example 7, the winding length exceeded 105 m and the winding diameter exceeded 134 mm, so that the roll diameter became large and it was difficult to fit in the toilet paper holder.

When the commercially available products 1 to 3 were evaluated in the same manner, the winding lengths were all less than 63 m, and the roll replacement frequency was high.

2 Embossing 10 Toilet roll 10x Toilet paper D Embossing depth

Claims (5)

A toilet roll which is laminated on two plies and has an embossed and non-chemical-coated toilet paper wound into a roll,
The emboss depth of the emboss is 0.05 to 0.40 mm,
The winding hardness is 0.3 to 1.4 mm, the winding length is 70 to 85 m, the winding diameter is 105 to 134 mm, and the winding density is 1.2 to 2.0 m/cm ² .
The basis weight of each sheet of the toilet paper is more than 13 g/m ² and 17 g/m ² or less,
A toilet roll having a tensile strength DMDT in a vertical direction of 2.5 to 4.5 N/25 mm when dried as a two-ply toilet paper. The toilet roll according to claim 1 , wherein the emboss is a single emboss . The toilet roll according to claim 1 or 2, wherein the toilet paper contains kraft pulp in an amount of 40 to 100% by mass . The toilet roll according to any one of claims 1 to 3, which contains more than 0% by mass and 60% by mass or less of waste paper pulp derived from a milk carton . Through a whiteness UV-in conforming to ISO 2470 when a C light source specified by CIE (International Commission on Illumination) is applied to the surface side of the toilet paper, and a filter that cuts off ultraviolet light having a wavelength of 420 nm or less, The difference Δ with the whiteness UV-cut in accordance with ISO 2470 when the surface of the toilet paper is irradiated with the C light source is 0.0 to 2.5 points. Toilet roll described in.