Methods for manufacturing toilet paper rolls

Abstract

The invention relates to a method of manufacturing toilet paper rolls by which, when four-ply toilet paper is torn, the individually layered sheets of paper are prevented from separating from each other and good external shape is ensured. A sprayer (22a) sprays adhesive liquid between two single-ply sheets (110 and 111), a sprayer (22b) sprays adhesive liquid between two single-ply sheets (111 and 100), a sprayer (22c) sprays adhesive liquid between two single-ply sheets (100 and 101), and a pressure roller (23) stacks the single-ply sheets (110, 111, 100, and 101) and applies pressure to them.

Description

How toilet paper rolls are made

[0001] The present disclosure relates to a method for manufacturing a four-ply toilet paper roll in which four sheets of paper are stacked and wound.

[0002] Conventionally, toilet paper rolls with one sheet of paper wound up (one ply) and two-ply toilet paper rolls with two sheets of base paper wound up have been manufactured and sold. To increase water absorbency, toilet paper rolls with three or more sheets of paper wound up are also manufactured and sold. When three or more sheets of paper are stacked as described above, the thickness of the stacked paper becomes quite large, making it difficult to separate the portion of the paper roll that has been pulled out. Some paper rolls with three or more sheets of paper stacked up have perforations at regular intervals to make it easier to separate the stacked paper that has been pulled out from the paper roll.

[0003] For example, when manufacturing a three-ply toilet paper roll, one ply on the front side and at least one ply on the middle layer are bonded together using glue, and two plies on the back side are micro-embossed, and these are laminated together to make the plies less likely to peel off. Also, when manufacturing a four-ply toilet paper roll, two plies on the front side are formed with decorative embossing, and two plies on the back side are formed with micro-embossing. One ply on the back side of at least two plies on the front side and one ply on the front side of at least two plies on the back side are bonded together using glue (Patent Document 1).

[0004] In the above-mentioned four-ply toilet paper roll, two of the four plies that form the middle layers are glued together. Furthermore, large decorative embossings are formed on the two outer layers of the four plies, and micro-embossings formed on the two glued layers (middle layers) are firmly abutted against the decorative embossings, making them difficult to peel off. In addition, some four-ply toilet paper rolls have a decorative embossing formed on one ply on the front side and a micro-embossing formed on three plies on the back side, with the one ply on the front side and the second ply from the front side glued together with glue.

[0005] Japanese Patent Application Laid-Open No. 2018-23561

[0006] A four-ply toilet paper roll manufactured by stacking multiple sheets of paper as described above has portions where embossments of different sizes are tightly pressed together without using adhesive liquids such as water or glue. Therefore, when the roll is attached to a toilet paper holder and cut to the desired length, the stacked sheets may peel off from the cut end. If the stacked sheets peel off and protrude from the toilet paper holder in this state, the appearance will be poor.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and provides a method for manufacturing a toilet paper roll that prevents the layers of paper from peeling off when the paper pulled out from a four-ply toilet paper roll is separated, thereby improving the appearance.

[0008] The method for manufacturing a toilet paper roll according to the present disclosure comprises a first step of drawing out base paper from a plurality of base paper rolls, a second step of introducing a plurality of the base papers into a laminating section and laminating the plurality of base papers to form a four-ply toilet paper, a third step of drying the four-ply toilet paper, and a fourth step of winding up the four-ply toilet paper to manufacture a four-ply toilet paper roll, wherein the second step separates the plurality of base papers introduced into the laminating section into a first one-ply paper, a second one-ply paper, a third one-ply paper, and a fourth one-ply paper, and faces the back surface of the first one-ply paper to the front surface of the second one-ply paper, and faces the back surface of the second one-ply paper to the front surface of the third one-ply paper. a fifth step of placing the third one-ply paper and the fourth one-ply paper facing each other so that the back surface of the third one-ply paper faces the front surface of the fourth one-ply paper; a sixth step of using a first sprayer to spray adhesive liquid onto the back surface of the first one-ply paper and the front surface of the second one-ply paper; a seventh step of using a second sprayer to spray the adhesive liquid onto the back surface of the second one-ply paper and the front surface of the third one-ply paper; an eighth step of using a third sprayer to spray the adhesive liquid onto the back surface of the third one-ply paper and the front surface of the fourth one-ply paper; and a ninth step of using a pressure roller to overlap the first one-ply paper, the second one-ply paper, the third one-ply paper, and the fourth one-ply paper and apply pressure to penetrate the adhesive liquid.

[0009] The second step is characterized in that the sixth step, the seventh step, and the eighth step are carried out simultaneously.

[0010] The second step is characterized in that the sixth step, the seventh step, and the eighth step are intermittently repeated so that spraying of the adhesive liquid by the first sprayer and the third sprayer and spraying of the adhesive liquid by the second sprayer are alternately performed.

[0011] The second step is characterized in that the sixth step, the seventh step, and the eighth step are intermittently repeated so that the adhesive liquid is sprayed intermittently from the first sprayer, the second sprayer, and the third sprayer for different lengths of time, respectively.

[0012] The seventh step is characterized in that the amount of adhesive liquid sprayed from the second sprayer is less than the amount of adhesive liquid sprayed from the first sprayer and the amount of adhesive liquid sprayed from the third sprayer.

[0013] The seventh step is characterized in that the amount of adhesive liquid sprayed from the second sprayer is greater than the amount of adhesive liquid sprayed from the first sprayer and the amount of adhesive liquid sprayed from the third sprayer.

[0014] According to the present disclosure, when the paper is pulled out from a four-ply toilet paper roll and separated, peeling of the individual layers of the paper can be prevented, resulting in a beautiful appearance.

[0015] 1 is an explanatory diagram showing a schematic configuration of a paper roll manufacturing apparatus that uses a toilet paper roll manufacturing method according to an embodiment of the present disclosure. FIG. 2 is an explanatory diagram showing a schematic configuration of a stacking unit provided in the toilet paper roll manufacturing apparatus of FIG.

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described. (Embodiment) Fig. 1 is an explanatory diagram showing a schematic configuration of a toilet paper roll manufacturing device 1 that uses a toilet paper roll manufacturing method according to an embodiment of the present disclosure.

[0017] The toilet paper roll manufacturing apparatus 1 is configured to manufacture a 4-ply toilet paper roll 300, and includes, for example, a base paper roll 10, a guide roller 2 that moves the base paper 10a and base paper 11a that are respectively drawn out from the base paper roll 11 to the lamination unit 20, and a lamination unit 20 that uses the base paper 10a and base paper 11a to form 4-ply toilet paper 200 as described below. The toilet paper roll manufacturing apparatus 1 also includes a drying unit 30 that dries the 4-ply toilet paper 200, and a winding unit 40 that winds up the dried 4-ply toilet paper 200 to form the 4-ply toilet paper roll 300.

[0018] The base paper 10a and base paper 11a exemplified here are two-ply base paper sheets made by overlapping two sheets of paper. The toilet paper roll manufacturing apparatus 1 exemplified in Figure 1 is configured to introduce two plies of base paper 10a, 11a into the stacking unit 20 to manufacture a four-ply toilet paper roll 300, but the toilet paper roll manufacturing apparatus according to the present invention may also be configured to supply one ply of base paper from each of four base paper rolls to the stacking unit 20. The toilet paper roll manufacturing apparatus 1 in Figure 1 is provided with a plurality of guide rollers 2 so as to introduce, for example, the base paper 10a unwound from the base paper roll 10 and the base paper 11a unwound from the base paper roll 11 into the stacking unit 20, respectively.

[0019] Figure 2 is an explanatory diagram showing the schematic configuration of the laminating unit 20 provided in the toilet paper roll manufacturing apparatus 1 of Figure 1. The laminating unit 20 includes, for example, a plurality of guide rollers 21 arranged to separate the two-ply base paper 10a supplied from the base paper roll 10 into one-ply paper sheets 100 and one-ply paper sheets 101 and transport each of them near the sprayers 22c. The plurality of guide rollers 21 provided in the laminating unit 20 are also arranged to separate the two-ply base paper 11a supplied from the base paper roll 11 into one-ply paper sheets 110 and one-ply paper sheets 111 and transport each of them near the sprayers 22a. Each guide roller 21 is arranged so that the transported one-ply paper sheets 100 approach both the sprayers 22c and 22b as described above. Each guide roller 21 is also arranged so that the transported one-ply paper sheets 111 approach both the sprayers 22a and 22b as described above.

[0020] In other words, the laminating unit 20 is provided with a plurality of guide rollers 21 so that when the two-ply base paper 10a, 11a is introduced, the laminating unit 20 separates the base paper 10a into one-ply paper sheets 100 and 101, and also separates the base paper 11a into one-ply paper sheets 110 and 111. The laminating unit 20 also has a plurality of guide rollers 21 so that the one-ply paper sheets 110, 111, 100, 101 separated as described above are overlapped and sandwiched between the pressing rollers 23. The pressing rollers 23 are configured to overlap the one-ply paper sheets 110, 111, 100, 101 and apply an appropriate pressure to form four-ply toilet paper 200.

[0021] The lamination unit 20 also includes a sprayer 22a for spraying adhesive liquid between the one-ply papers 110 and 111 before the one-ply papers 110, 111, 100, and 101 are sandwiched between the pressure rollers 23, a sprayer 22b for spraying adhesive liquid between the one-ply papers 111 and 100, and a sprayer 22c for spraying adhesive liquid between the one-ply papers 100 and 101. The adhesive liquid may be water or an aqueous solution containing a fragrance or deodorizing component. Regarding the adhesive liquid used by the sprayers 22a, 22b, and 22c, for example, water may be sprayed from one of the sprayers and an aqueous solution containing, for example, a fragrance component may be sprayed from the other two, thereby enabling control of the concentration of the functional aqueous solution.

[0022] Next, the operation will be described. In the toilet paper roll manufacturing apparatus 1 of Figure 1, for example, long, two-ply base paper 10a, 11a is pulled out from two base paper rolls 10, 11, and transferred to the laminating unit 20 using multiple guide rollers 2. The laminating unit 20 applies an adhesive liquid to the base paper 10a, 11a introduced by each guide roller 2, as described below, and laminates them to form a long, four-ply toilet paper 200. The four-ply toilet paper 200 formed by the laminating unit 20 is introduced from the laminating unit 20 to the drying unit 30.

[0023] The drying unit 30, for example, has a plurality of cylinders inside, and heats the four-ply toilet paper 200 introduced into the drying unit 30 by passing it through each of the cylinders, thereby drying the four-ply toilet paper 200. The four-ply toilet paper 200 dried by the drying unit 30 is introduced into the winding unit 40. The winding unit 40 uses a winding pressure roller 42 and a plurality of winding rollers 43 to wind up the four-ply toilet paper 200 introduced into the winding unit 40, thereby producing a four-ply toilet paper roll 300.

[0024] The winding unit 40 is also equipped with a cutter 41, and after a predetermined length of four-ply toilet paper 200 has been wound up by the winding pressure roller 42 and winding roller 43, the cutter 41 is used to cut the four-ply toilet paper 200 introduced into the winding unit 40. The winding unit 40 sequentially winds up the four-ply toilet paper 200 supplied from the drying unit 30, and repeatedly cuts the four-ply toilet paper 200 using the cutter 41 as described above, thereby manufacturing a four-ply toilet paper roll 300. Note that the winding unit 40 may also be equipped with a cutter (not shown) that forms perforations in the width direction of the four-ply toilet paper 200, for example, to form perforations in the four-ply toilet paper 200 at predetermined intervals, thereby manufacturing a four-ply toilet paper roll 300 with the perforations.

[0025] Next, the operation of laminating the one-ply paper sheets 110, 111, 100, and 101 performed by the laminating unit 20 to form the four-ply toilet paper sheet 200 will be described. When the base paper sheets 10a and 11a are introduced into the laminating unit 20, they are passed through the guide rollers 21 to separate the base paper sheets 10a into one-ply paper sheets 100 and 101. Similarly to the base paper sheets 10a, the laminating unit 20 separates the base paper sheets 11a into one-ply paper sheets 110 and 111. The one-ply paper sheets 110, 111, 100, and 101 that have passed through the guide rollers 21 are, for example, placed in a state where the back surface of the one-ply paper sheet 110 faces the front surface of the one-ply paper sheet 111. The front surface of the one-ply paper sheet 111 faces the front surface of the one-ply paper sheet 100, and the back surface of the one-ply paper sheet 100 faces the front surface of the one-ply paper sheet 101.

[0026] The one-ply papers 110, 111, 100, and 101, each with its surface facing each other as described above, are transported toward the pressure roller 23 by the guide rollers 21 with an appropriate gap between them. As described above, the laminating unit 20 is equipped with sprayers 22a, 22b, and 22c that spray (apply) adhesive liquid to each surface of the one-ply papers 110, 111, 100, and 101 transported by the guide rollers 21, and the sprayers 22a, 22b, and 22c are installed between the positions where the base papers 10a and 11a are separated by the guide rollers 21 into the one-ply papers 110, 111, 100, and 101, respectively, and the installation position of the pressure roller 23 that overlaps the one-ply papers 110, 111, 100, and 101. The sprayers 22a, 22b, and 22c are configured to spray the adhesive liquid into a predetermined position and space.

[0027] Sprayer 22a is installed, for example, to apply adhesive liquid to the back surface of one-ply paper 110 and the front surface of one-ply paper 111. Sprayer 22b is installed, for example, to apply adhesive liquid to the back surface of one-ply paper 111 and the front surface of one-ply paper 100. Sprayer 22c is installed, for example, to apply adhesive liquid to the back surface of one-ply paper 100 and the front surface of one-ply paper 101.

[0028] Furthermore, when the one-ply papers 110, 111, 100, 101 passing through each guide roller 21 are sandwiched between the pressure rollers 23, the gap between these papers narrows. In the toilet paper roll manufacturing apparatus 1 illustrated in Figure 1, sprayers 22a, 22b, 22c are installed near the pressure rollers 23 where the gap between the papers narrows, in order to ensure that the adhesive liquid is applied to the front or back surface of each of the above-mentioned papers. The configuration of the toilet paper roll manufacturing apparatus 1 that implements the toilet paper roll manufacturing method of the present invention is not limited to the installation positions of the sprayers 22a, 22b, 22c shown in Figure 1.

[0029] The lamination unit 20 may, for example, spray adhesive liquid from the sprayers 22a, 22b, and 22c simultaneously onto the front or back surface of each of the papers. Alternatively, for example, the sprayer 22b may be operated first to apply adhesive liquid to the back surface of the one-ply paper 111 and the front surface of the one-ply paper 100, and then the sprayers 22a and 22c may be operated to apply adhesive liquid to the back surface of the one-ply paper 110 and the front surface of the one-ply paper 111, and the back surface of the one-ply paper 100 and the front surface of the one-ply paper 101, respectively. Alternatively, the sprayers 22a and 22c may be operated first to apply adhesive liquid to the back surface of the one-ply paper 110 and the front surface of the one-ply paper 111, and the back surface of the one-ply paper 100 and the front surface of the one-ply paper 101, respectively, and then the sprayer 22b may be operated to apply adhesive liquid to the back surface of the one-ply paper 111 and the front surface of the one-ply paper 100.

[0030] As described above, the one-ply papers 110 and 101 have the adhesive liquid sprayed on only one side, but the one-ply papers 111 and 100 have the adhesive liquid sprayed on both sides. Therefore, the strength of the one-ply papers 111 and 100 is more likely to decrease due to the adhesive liquid adhering thereto than the one-ply papers 110 and 101. As described above, the timing (operation) of spraying the adhesive liquid from the sprayer 22b onto the one-ply papers 111 and 100 may be made different from the timing (operation) of spraying the adhesive liquid from the sprayers 22a and 22c, thereby preventing damage to the one-ply papers 111 and 100.

[0031] Specifically, the spraying operations of the sprayers 22a, 22b, and 22c are repeated intermittently. For example, the spraying timing of the sprayers 22a and 22c is staggered from the spraying timing of the sprayer 22b. That is, the spraying by the sprayers 22a and 22c and the spraying by the sprayer 22b are alternately performed. Furthermore, when spraying is performed intermittently as described above, the spraying by the sprayers 22a, 22b, and 22c may be performed for different lengths of time. For example, the spraying time of the sprayer 22b may be shorter than the spraying time of the sprayers 22a and 22c. Furthermore, if the one-ply paper 111, 100 has sufficient strength to withstand the penetration of the adhesive liquid, the spraying time of the sprayer 22b may be longer than the spraying time of the sprayers 22a and 22c.

[0032] Furthermore, as mentioned above, since the adhesive liquid adheres to both the front and back surfaces of the one-ply papers 111 and 100, the amount of adhesive liquid sprayed from sprayer 22b may be made less than the amount of adhesive liquid sprayed from sprayer 22a and sprayer 22c, respectively, and adjusted to be an appropriate amount relative to the amount of adhesive liquid adhering to the one-ply papers 110 and 101.

[0033] If the adhesive liquid has high permeability to the one-ply paper sheets 110, 111, 100, and 101, for example, the amount of adhesive liquid sprayed from the sprayer 22b may be the largest, i.e., a large amount of adhesive liquid is applied to the one-ply paper sheets 111 and 100 that constitute the middle layer of the four-ply toilet paper 200. Alternatively, the amount of adhesive liquid sprayed from the sprayers 22a and 22c may be less than the amount sprayed from the sprayer 22b, i.e., a small amount of adhesive liquid is applied to the one-ply paper sheets 110 and 101 that constitute the outer layer of the four-ply toilet paper 200, and the adhesive liquid is permeated from the middle layer toward the outer layer by the pressure of the pressure roller 23 described below. This is expected to reduce damage to the one-ply paper sheets 110 and 101 that constitute the outer layer of the four-ply toilet paper 200 (four-ply toilet paper roll 300).

[0034] Furthermore, if the adhesive liquid has a fairly high permeability, it is possible to spray an appropriate amount of adhesive liquid only from the sprayer 22b, and when pressure is applied by the pressure roller 23, the adhesive liquid will permeate all of the one-ply papers 110, 111, 100, and 101, thereby forming a four-ply toilet paper 200.

[0035] The one-ply papers 110, 111, 100, and 101 to which the adhesive liquid has been applied are sandwiched between pressure rollers 23, with the back surface of the one-ply paper 110 abutting against the front surface of the one-ply paper 111, the back surface of the one-ply paper 111 abutting against the front surface of the one-ply paper 100, and the back surface of the one-ply paper 100 abutting against the front surface of the one-ply paper 101. The pressure rollers 23 cause the adhesive liquid to penetrate between the fibers of the one-ply papers 110, 111, 100, and 101, and also apply pressure such that the back surface fibers of the one-ply paper 110 and the front surface fibers of the one-ply paper 111 intertwine, the back surface fibers of the one-ply paper 111 and the front surface fibers of the one-ply paper 100 intertwine, and the back surface fibers of the one-ply paper 100 and the front surface fibers of the one-ply paper 101 intertwine. By applying the pressure described above, the pressure roller 23 bonds the one-ply papers 110, 111, 100, and 101 together, forming the four-ply toilet paper 200.

[0036] The four-ply toilet paper 200 formed by the pressure roller 23 is dried in the drying section 30 as described above, and then wound up in the winding section 40 to produce a four-ply toilet paper roll 300.

[0037] According to the embodiment described above, adhesive liquid is applied between each of the one-ply papers 110, 111, 100, 101, and the pressure roller 23 causes the adhesive liquid to penetrate into the one-ply papers 110, 111, 100, 101 to form the four-ply toilet paper roll 300 (four-ply toilet paper 200). This allows the adhesive liquid to penetrate in the thickness direction of the four-ply toilet paper 200 (the stacking direction of the one-ply papers 110, 111, 100, 101) and in the direction along the front (back) side of the four-ply toilet paper 200, and when the paper pulled out from the four-ply toilet paper roll 300 is cut off at any length, it is possible to prevent the one-ply papers 110, 111, 100, 101 from separating and peeling off. Furthermore, the amount of adhesive liquid applied between each of the one-ply papers 110, 111, 100, and 101 can be adjusted, and the adhesive strength between each of the one-ply papers 110, 111, 100, and 101 can be set as desired.

[0038] REFERENCE SIGNS LIST 1 Toilet paper roll manufacturing apparatus 2 Guide roller 10 Base paper roll 10a Base paper 11 Base paper roll 11a Base paper 20 Laminating section 21 Guide roller 22a, 22b, 22c Sprayer 23 Pressing roller 30 Drying section 40 Winding section 41 Cutter 42 Winding pressure roller 43 Winding roller 100 1-ply paper 101 1-ply paper 110 1-ply paper 111 1-ply paper 200 4-ply toilet paper 300 4-ply toilet paper roll

Claims

1. A toilet paper manufacturing system comprising: a first step of drawing out base paper from a plurality of base paper rolls; a second step of introducing a plurality of the base papers into a stacking section and stacking the plurality of base papers to form a four-ply toilet paper; a third step of drying the four-ply toilet paper; and a fourth step of winding up the four-ply toilet paper to manufacture a four-ply toilet paper roll, wherein the second step comprises: a fifth step of separating the plurality of base papers introduced into the stacking section into a first one-ply paper, a second one-ply paper, a third one-ply paper, and a fourth one-ply paper, and arranging the back surface of the first one-ply paper to face the front surface of the second one-ply paper, the back surface of the second one-ply paper to face the front surface of the third one-ply paper, and the back surface of the third one-ply paper to face the front surface of the fourth one-ply paper; and a sixth step of using a first sprayer to spray adhesive liquid onto the back surface of the first one-ply paper and the front surface of the second one-ply paper. A method for manufacturing a toilet paper roll, comprising: a seventh step in which a second sprayer sprays the adhesive liquid onto the back surface of the second one-ply paper and the front surface of the third one-ply paper; an eighth step in which a third sprayer sprays the adhesive liquid onto the back surface of the third one-ply paper and the front surface of the fourth one-ply paper; and a ninth step in which a pressure roller overlaps the first one-ply paper, the second one-ply paper, the third one-ply paper, and the fourth one-ply paper, and applies pressure to penetrate the adhesive liquid.

2. The method for manufacturing a toilet paper roll according to claim 1, characterized in that the second step is performed simultaneously with the sixth step, the seventh step, and the eighth step.

3. The method for manufacturing a toilet paper roll according to claim 1, characterized in that in the second step, the sixth step, the seventh step, and the eighth step are intermittently repeated so that spraying of the adhesive liquid by the first sprayer and the third sprayer and spraying of the adhesive liquid by the second sprayer are alternately performed.

4. The method for manufacturing a toilet paper roll according to claim 1, characterized in that in the second step, the sixth step, the seventh step, and the eighth step are intermittently repeated so that the adhesive liquid is sprayed intermittently from the first sprayer, the second sprayer, and the third sprayer for different lengths of time, respectively.

5. A method for manufacturing a toilet paper roll as described in any one of claims 1 to 4, characterized in that in the seventh step, the amount of adhesive liquid sprayed from the second sprayer is less than the amount of adhesive liquid sprayed from the first sprayer and the amount of adhesive liquid sprayed from the third sprayer.

6. A method for manufacturing a toilet paper roll as described in any one of claims 1 to 4, characterized in that in the seventh step, the amount of adhesive liquid sprayed from the second sprayer is greater than the amount of adhesive liquid sprayed from the first sprayer and the amount of adhesive liquid sprayed from the third sprayer.

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