JP2019103552A - Toilet paper and toilet roll, and method of manufacturing toilet paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a 2-ply toilet paper having both softness and resistance to tearing when dried and wet. A two-ply toilet paper is formed so as to have a tensile energy absorption amount (TEA) of 4.0 to 10.0 J / m2 in the length direction. Further, it is assumed that the geometric mean of the tensile strength in the predetermined direction and the tensile strength in the direction orthogonal to the predetermined direction at the time of drying is 0.70 to 0.95 N / 15 mm. These compromise softness and resistance to tearing during drying. Further, by setting the length-weighted average fiber length of the contained pulp component to 0.75 to 1.00 mm or the wet burst strength to 90 to 160 kPa, the resistance to tearing during wetting is ensured. [Selection diagram] Fig. 2

Description

  The present invention relates to a toilet paper, a toilet roll in the form of a roll of the toilet paper, and a method of manufacturing the toilet paper.

  A toilet paper product is manufactured by cutting one or two or more stacked toilet paper webs into a predetermined size, and provided as a toilet roll in which a long toilet paper is wound in a roll. There are many. A toilet paper produced from a single toilet paper web is referred to as a one-ply toilet paper, and a toilet paper produced from a two-ply toilet paper web is referred to as a two-ply toilet paper.

  Since the toilet paper is directly in contact with the skin, a soft, puffy touch or feel is required. On the other hand, since the toilet paper is generally used after being unwound from a roll, the preferred tensile strength at the time of use (resistance to the action of the tensile force for unwinding) Is required. However, the touch feeling and the tensile strength are in a trade-off relationship, and many patent applications relating to the invention of toilet paper have been made for the purpose of combining these. For example, the applicant focused on the hand feel (HF) value, which is one of evaluation criteria for touch, and the compression ratio of the toilet paper, and the first side (outside surface) and the second side of the two-ply toilet paper. In addition to defining the average value of the HF value on the (inner surface), and by defining the relationship between the compression rate when different pressures are applied, a proposal has been made to achieve both sensory quality and tensile strength (patent document 1).

JP, 2017-169681, A

  An object of the present invention is to achieve both the difficulty of tearing and the touch feeling by designing the paper quality of the toilet paper based on criteria different from those of the prior art disclosed in Patent Document 1 and the like.

  Another object of the present invention is to provide a toilet paper having not only the dry strength prior to use but also the wet strength associated with use.

Therefore, the present invention is a two-ply toilet paper characterized in that the tensile energy absorption amount in a predetermined direction is 4.0 to 10.0 J / m ² . Here, the square root of the product of the tensile strength in the predetermined direction and the tensile strength in the direction orthogonal to the predetermined direction during drying can be 0.70 to 0.95 N / 15 mm. In addition, the length-weighted average fiber length of the contained pulp component may be 0.75 to 1.00 mm, or the wet burst strength may be 90 to 160 kPa.

  Further, the present invention resides in a toilet roll formed by forming the toilet paper into a roll shape such that the predetermined direction is the unwinding direction.

Furthermore, the present invention is a method for producing the above-mentioned toilet paper, which is perpendicular to the predetermined direction so as to adjust the elongation so that the tensile energy absorption amount becomes 6.0 to 12.0 J / m ^2. A method includes the step of creping a crepe extending along a direction parallel to the predetermined direction.

The 2-ply toilet paper according to the present invention is formed to have a tensile energy absorption amount (TEA) of 4.0 to 10.0 J / m ^{2 in} a predetermined direction (longitudinal direction). Further, the geometric mean of the tensile strength in the predetermined direction and the tensile strength in the direction orthogonal to the predetermined direction during drying is 0.70 to 0.95 N / 15 mm. These make a compromise between softness and tear when dry. Furthermore, when the length-weighted average fiber length of the contained pulp component is set to 0.75 to 1.00 mm, or the wet burst strength is set to 90 to 160 kPa, it is possible to realize the difficulty of breaking when wet.

(A) is a perspective view showing the appearance of a toilet roll to which the toilet paper according to one embodiment of the present invention is applied, (b) is a longitudinal view of the toilet paper along the line Ib-Ib in FIG. It is a figure which shows a part of cross section in direction (longitudinal direction) T. FIG. (A)-(c) is an explanatory view for explaining the principle of an embodiment.

  The present invention will be described in detail below with reference to the drawings. However, although the description of the configuration requirements described below may be made based on representative embodiments, specific examples, or modifications, the present invention is not limited thereto.

1. Configuration of Toilet Paper and Toilet Roll FIG. 1A is a perspective view showing an appearance of a toilet roll to which a toilet paper according to an embodiment of the present invention is applied. FIG. 1B is a view showing a part of a cross section in the longitudinal direction (longitudinal direction) T of the toilet paper which is a predetermined direction along the line Ib-Ib in FIG. The toilet roll 10 according to the present embodiment is formed by winding a toilet paper 11 formed by superposing two sheets (two plies) of long tissue 11a and 11b around a cylindrical winding core 14 by a predetermined length. It is. A large number of crepes 15 extending along a transverse direction (width direction) Y orthogonal to the longitudinal direction T are formed in parallel on the toilet paper 11 by performing creping in a paper making process described later. The stretchability in the longitudinal direction T is enhanced.

2. Design Guide for Paper Quality First, in examining the coexistence of the difficulty in tearing and the feeling of touch, the present inventors have guided the tensile energy absorption (TEA, also referred to as tensile energy absorption) as a guideline for paper quality design. I paid attention to it. The value of TEA (unit: J / m ² ) can be said to be the integral value of the tensile load-elongation curve before breaking in the tensile test of the toilet paper. That is, as shown in FIG. 2 (a), the tensile load and the elongation are measured in the process of the tensile test until the breakage occurs, and the area obtained by plotting the measured values is calculated as the area shown by oblique lines. It is a thing.

  Focusing simply on the degree of tearing, as shown in FIG. 2 (b), the tensile strength may be increased. The tensile strength can be increased by adjusting the amount of beating, the amount of strength agent applied, or the pulp component. However, simply increasing the tensile strength tends to make the paper harder, which reduces the softness or the feel of the toilet paper. Therefore, it may be necessary to make the above adjustment strictly in the manufacturing process so that the softness is not sacrificed.

Therefore, as shown in FIG. 2 (c), the present inventors thought that the value (area) of TEA was increased by increasing the elongation rate, and that both the feeling of touch and the difficulty of breaking were made compatible. Here, there is an index called a hand feel value (HF value) as a standard to objectively express touch feeling which is sensory evaluation etc., but in the case of toilet paper, if this HF value is larger than 70, the touch is generally about They tend to feel good. And, specifically, if the TEA in the length direction T is 4.0 to 10.0 J / m ² , it is difficult to tear when pulled out from the roll, and an HF value of more than 70 and We have found that we can achieve both

  In addition, in order to realize the coexistence of the softness and the difficulty of breaking more effectively, the present inventors are the product of the tensile strength in the length direction T at the time of drying and the tensile strength in the width direction Y at the time of drying. We focused on the square root of (geometric mean). Specifically, it has been found that the geometric mean of the tensile strength in those directions at the time of drying is preferably 0.70 to 0.95 N / 15 mm.

  Furthermore, the toilet paper is required to have not only the strength at the time of drying prior to use but also the strength at the time of use associated with the use. Therefore, the present inventors focused on the length-weighted average fiber length and wet burst strength of the pulp component contained in the toilet paper, and found that it is preferable that they are 0.75 to 1.00 mm and 90 to 160 kPa, respectively. I got

  The present inventors conducted experiments to verify the above findings. Moreover, the content and the range of each preferable value will be described later based on Table 1.

3. Method of Producing Toilet Paper In the method of producing toilet paper of the present invention, a step of making a slurry containing fiber raw materials to make a one-ply toilet paper web and laminating one ply of toilet paper webs (Also referred to as a combination step).

  Before the step of making the slurry, the step of bleaching the fiber material may be included. As a bleaching agent used at a bleaching process, well-known bleaching agents, such as an oxygen type bleaching agent and a chlorine type bleaching agent, can be mentioned.

  The step of obtaining a one-ply toilet paper web includes the step of obtaining a slurry containing a fiber material. The step of obtaining the slurry preferably includes a step of refining the fiber material. In the beating process, for example, a double disc refiner or the like can be used to perform a beating process. At this time, softwood pulp and hardwood pulp may be beaten alone or may be beaten after being mixed.

  The step of obtaining a one-ply toilet paper web includes the step of making a slurry containing the fiber material. As a paper machine used in the process of making paper, for example, a paper machine such as suction breast former (circular mesh type, long mesh type), twin wire former, circular mesh former (C wrap, S wrap), crescent foamer, etc. Can be mentioned.

  In the paper making process, a slurry containing a fiber material is supplied onto a reticulated wire to form a thin layer of pulp. Thereafter, the thin layer of pulp is dewatered by the moisture of the thin layer of pulp being extracted under the net while being transferred toward the press part. Such a process may be called a dehydration process. In general, the wire is a ring made of metal or plastic mesh.

  In the paper making process, for example, a method of forming a wet paper as a uniform single layer by making a pulp slurry in which softwood pulp and hardwood pulp are mixed to form a single layer, or by combining softwood pulp layer and hardwood pulp layer There is a method of forming a wet paper or the like, but any method may be adopted.

  After the dewatering process, the wet paper web moves from the wire to the felt. The wet paper web is further mechanically squeezed by applying pressure to the wet paper web with the press roll through the felt. This may be referred to as a pressing step or a squeezing step.

It is preferable that the paper making process further includes a drying process after the water squeezing process. The drying step is preferably, for example, a step of blowing hot air toward the wet paper, or a step of pressing the outer peripheral surface of the dryer cylinder. In the course of the drying step, dry creping is applied to form a crepe from which the TEA values according to the invention are obtained. However, the wet paper may be wet creped in the process of the dewatering step or the pressing step to form a crepe which can obtain a TEA value of 4.0 to 10.0 J / m ² .

  After the drying step, a base paper winding step is provided. In the base paper winding process, the one-ply base paper winding can be obtained by winding up the toilet paper web (thin paper) finished through the above steps. Under the present circumstances, it is preferable to wind up so that the 1st surface (outer surface) of a toilet paper web (thin paper) may become an outer peripheral surface of base paper winding.

  In the step of laminating the one-ply toilet paper webs (bonding step), two one-ply base paper rolls obtained in the above-described step are prepared. Two rolls of the base paper are wound on a processing machine to perform embossing on the surface of the base paper and bonding to two plies while unwinding. Under the present circumstances, it is preferable to bond together to 2 ply so that 1st surfaces (outer surface) of 1-ply base paper winding may come outside.

  In the present invention, by defining the range of the TEA value as described above, it is possible to realize both the softness and the difficulty in breaking, and it is effective that the embossing as disclosed in Patent Document 1 is given. Although it does not have conditions, it does not exclude the process of embossing. When carrying out embossing, it carries out by pressing with the embossing roll to which the embossing was provided. By changing the pressing amount or pressing pressure of the embossing roll, it is possible to form an embossing shape having a predetermined embossing height. The embossing may be performed before the bonding step as described later, or may be performed after the bonding step. In addition, it is preferable to perform embossing before a bonding process from a viewpoint of improving a touch feeling.

  In the bonding step, two 1-ply toilet paper webs are stacked and bonded. In this step, for example, after laminating the base paper, it is possible to bond by applying narrow contact emboss to a portion to be an end of the product. At that time, it is preferable from the viewpoint of feel to touch that the surface pressed by the emboss roll be outside.

  A winding process is further provided after the bonding process. In the winding process, winding is performed for a predetermined length so as to satisfy a predetermined product length. And the toilet roll 10 shown to FIG. 1 (a) and (b) is formed by cutting the roll of the obtained toilet paper base paper in predetermined width.

  In addition to the fiber material, the toilet paper of the present embodiment may contain optional components. As an optional component, for example, a dry strength agent, a wet strength agent, a softener and the like can be mentioned.

4. Examples and Comparative Examples The present inventors verified the above findings on the basis of Examples 1 to 6 of toilet paper manufactured according to the guidelines of the present embodiment and Comparative Examples 1 and 2 which are not so. Table 1 summarizes the paper thickness and other specifications of Examples 1 to 6 and Comparative Examples 1 and 2 and also summarizes the results of their sensory evaluation. However, the specifications, processing contents, processing procedures, and the like shown in the following embodiments can be appropriately changed without departing from the spirit of the present invention. That is, the scope of the present invention should not be construed as limited by the following examples.

4.1 Specifications First, the meanings and measurement methods of the main specifications according to the embodiment will be described.

Basis Weight The basis weight of the toilet paper obtained in Examples and Comparative Examples was measured in accordance with JIS P 8124. The basis weight shown in Table 1 is a value for one ply.

Paper Thickness The paper thickness of the 2-ply toilet paper was read using a thickness gauge (manufactured by High Bridge Mfg. Co., Ltd.) when the measuring element was lowered at a speed of 1 mm or less per second. The paper thickness was obtained by calculating the average value of eight samples. The paper thickness was measured in an environment (temperature 23 ± 1 ° C., relative humidity 50 ± 2%) in accordance with ISO 187.

Length-weighted average fiber length A fiber component (pulp component) contained in the toilet paper, and a weighted fiber length obtained by disaggregating the fiber component (pulp component) contained in the toilet paper Fiber length, which is sometimes called disaggregated fiber length. As the fiber component (pulp component), various ones may be employed, and they may be mixed and used. The weighted average fiber length is a fiber length calculated by the following measurement method.

  First, a fiber dispersion slurry obtained by deaggregating toilet paper in water is prepared. The fiber dispersion slurry is obtained by placing 4 g of toilet paper in 200 ml of water, operating the disintegrator at 4500 rpm and agitating until sufficient disaggregation. The obtained fiber dispersion slurry is diluted to be 0.01% by mass or more and 0.02% by mass or less to prepare a diluted solution. The projected length of the fiber component contained in 10 ml of this diluted solution is measured using a fiber length measurement apparatus (Kajani Fiber Lab Ver 4.0, manufactured by Metso Automation Co., Ltd.), and the length-weighted average value of the disaggregated fibers is calculated.

Tensile test of each 2-ply toilet paper is carried out using a horizontal tensile tester (manufactured by Kumagaya Riki Kogyo Co., Ltd.) in accordance with dry tensile strength, elongation, TEA and Young's modulus JIS P 8113, and tensile load and elongation And while measuring the dry tensile strength, the elongation rate and the Young's modulus were calculated. This measurement was performed using a sample with a width of 15 mm under conditions of a tensile speed of 50 mm / min and a span length of 100 mm. The tensile strength is measured in an environment (temperature 23 ± 1 ° C., relative humidity 50 ± 2%) in accordance with ISO 187. When measuring the tensile strength, the tensile load and elongation obtained until the toilet paper broke were plotted to obtain a tensile load-elongation curve, and TEA was calculated. In addition, Young's modulus was calculated based on the value of the paper thickness. Each physical property value is an average value of all six samples.

Wet Burst Strength Wet burst strength was measured as follows.
First, a toilet paper is cut into 5 × 5 cm, and a test piece in which 60 sheets (corresponding to 30 sets) are stacked is manufactured, and the weight is measured. After immersing the test piece in pure water at 23 ° C., excess water is removed by a filter paper (Toho Filter Paper Co., Ltd. Standard Filter Paper No. 26), and the weight is measured again. After confirming that the moisture content of the test piece is 175% or more and 200% or less, the burst strength (kPa) is measured with a low pressure type burst tester (2021-C, manufactured by Kumagaya Riki Kogyo Co., Ltd.). The average value of six measurements is calculated as the wet burst strength. The wet burst strength is measured in an environment (temperature 23 ± 1 ° C., relative humidity 50 ± 2%) in accordance with ISO 187. The moisture content of the toilet paper is a value calculated by the following equation.
Moisture content (%) = (specimen weight difference before and after immersion) x 100 / specimen weight before immersion

HF
The hand feel value (HF value) was measured by the following measurement method using a tissue softness analyzer (manufactured by Emtec Electronic GmbH).

  First, a sample having a diameter of 112.8 mm is cut on a sample table of a tissue softness analyzer. The bladed rotor is pushed from above with a pushing pressure of 100 mN against this sample. Thereafter, the bladed rotor is rotated so as to have a rotational speed of 2.0 revolutions / second, and the vibration frequency at that time is measured. Further, with respect to another sample cut into a circular shape having a diameter of 112.8 mm, the amount of deformation displacement in the vertical direction when the bladed rotor is pushed in at a pressure of 100 mN and 600 mN is calculated. The HF value is a value calculated from the vibration frequency and the amount of deformation displacement, and the calculation algorithm can use TPII.

  When calculating the HF value, the first side of each sample (the outer side of the ply on the outer side of the roll of toilet paper consisting of two plies) and the second side (the core side of the toilet paper consisting of two plies) The inner surface of the ply of 10) was carried out 10 times each, and the average value was taken as the HF value in this embodiment.

  In addition, the measurement of the said sample was performed in the environment (temperature 23 +/- 1 degreeC, relative humidity 50 +/- 2%) based on ISO187. Further, at the time of measurement, calibration was performed using a standard sample (emetec ref. 2X (nn. N)) according to the instruction attached to the tissue softness analyzer, and the algorithm was set to TPII. As calculation software, emetec measurement system ver. 3.22 was used.

4.2 Sensory evaluation
A sensory evaluation was carried out on the toilet paper according to Examples 1 to 6 and Comparative Examples 1 and 2 having the specifications measured as described above in terms of hardness, softness and wet strength. Evaluation was performed on the following basis. That is, sensory evaluation was implemented in the state which concealed the level about the toilet paper obtained in Examples 1-6 and Comparative Examples 1 and 2. The product was touched by 50 monitors, and 3 points that felt "very good" with regard to the product's resistance to tear, softness and wet strength were felt "good" I was asked to do a four-step evaluation with two points, one that felt "somewhat inferior" and one that felt "poor." In the symbols ◎, 、, お よ び and X shown in Table 1, the average value of the evaluation points of the entire 50 persons is 2.25 to 3, 1.5 to 2.25, and 0.75 to 1.5, respectively. Points and those of 0 to 0.75 are shown.

5. Conclusion As is clear from the comparison of sensory evaluations of Examples 1 to 6, when the TEA of the 2-ply toilet paper is 4.0 to 10.0 J / m ² , it is difficult to tear when pulled out from the roll, It was concluded that they were almost compatible with the HF value of over 70, which is an index of softness. If the lower limit value of TEA is 5.0 J / m ² or more, the geometric mean of the tensile strength in the length direction T and the tensile strength in the width direction Y at the time of drying is 0.70 to 0.95 N / It was confirmed that 15 mm is more preferable because sensory evaluation of hardness and softness in tearing is enhanced.

  In addition, if the length-weighted average fiber length is 0.75 to 1.00 mm, or if the wet burst strength is 90 to 160 kPa, the hardness and softness are compatible while the sensory evaluation of the wet strength is enhanced. So preferred. If the Young's modulus in the length direction T is 10 to 30 GPa, the sensory evaluation of hardness on tearing is high, and if the upper limit is 15 GPa or less, the HF value is further increased, which is more preferable.

  On the other hand, in Comparative Example 1, the TEA is too small. In this case, although the HF value is high to some extent and the softness evaluation is relatively good, the sensory evaluation of the tear resistance and the wet strength is inferior. It has become. In addition, in Comparative Example 2, the TEA is excessive. In this case, although the sensory evaluation of the hardness is high, the HF value is low and the sensory evaluation of the softness is inferior.

Claims (6)

A two-ply toilet paper, wherein a tensile energy absorption amount in a predetermined direction is 4.0 to 10.0 J / m ² .   The toilet according to claim 1, wherein the square root of the product of the tensile strength in the predetermined direction and the tensile strength in the direction orthogonal to the predetermined direction during drying is 0.70 to 0.95 N / 15 mm. paper.   The toilet paper according to claim 1 or 2, characterized in that the length weighted average fiber length of the contained pulp component is 0.75 to 1.00 mm.   The wet burst strength is 90 to 160 kPa, The toilet paper as described in any one of the Claims 1 thru | or 3 characterized by the above-mentioned.   A toilet roll comprising the toilet paper according to any one of claims 1 to 4 formed into a roll so that the predetermined direction is the unwinding direction. A method for producing a toilet paper according to any one of claims 1 to 4, wherein the elongation is adjusted so that the tensile energy absorption amount is 4.0 to 10.0 J / m ² . A method comprising: creping a crepe extending along a direction orthogonal to the predetermined direction in parallel to the predetermined direction.

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