JP7610331B2 - Hand towel laminate and method of manufacturing same - Google Patents

Description

The present invention relates to a hand towel laminate and a method for manufacturing the same.

Paper hand towels are used in restrooms and bathrooms to dry hands after washing them. They are also increasingly being used in various manufacturing sites for hygiene management purposes, such as for washing hands in food production, cooking, serving food, and in the production and packaging of hygienic products, and there is a demand for improved production capacity for hand towels with excellent absorbency.

Hand towels are sold and used as laminates in which the sheets are folded alternately and can be removed one after the other in a pop-up style. Such hand towel laminates are manufactured using an interfolder (I/F) processing machine or a multifolder (M/F; multi-stand interfolder) processing machine, which is equipment capable of mass production at higher speeds.

Figure 1 is a perspective view that explains the direction in which a sheet is removed from the stack of the M/F processing machine.

When manufacturing using an M/F processing machine, as shown in Figure 1 (see arrow D1), the sheet is removed from the laminate in the CD (cross direction) direction rather than the MD (machine direction) direction.

For example, Patent Document 1 discloses a sheet folding equipment in which a continuous sheet is supplied onto a sheet stack being transported on a conveyor belt line, and multiple folding machines are installed at intervals along the line to fold two sheets so that the sides of the sheets are wrapped around the other sheets in an approximately C-shape, the conveyor belt line has a transport force applying device that applies a transport force by pinching the sheets between upper and lower belts at multiple positions among the groups of multiple folding machines, and a feeding force applying device is not installed at multiple other positions, and a pair of nip rolls is provided at multiple other positions where no feeding force applying device is installed, which nips the entire width of the sheet stack on the lower belt together with the lower belt, and the upper roll of the pair of nip rolls is driven to rotate at a peripheral speed approximately the same as the transport speed, and the lower roll is driven to rotate at a peripheral speed approximately the same as the transport speed or rotates freely.

Patent No. 3968368

However, when processing is performed using the above-mentioned M/F processing machine, it is superior to interfolder (I/F) processing machines and the like in that high-speed production is possible, but as shown in Figure 1, when the sheet is made into a laminate, the removal direction of the sheet is the CD direction rather than the MD direction, so the sheet strength is low and it breaks easily, resulting in a problem of poor removal.

Furthermore, hand towels are thicker than tissue paper and have a large difference in the folding length between the inside and outside. Also, due to the characteristics of dry crepe paper used in hand towels, etc., they have low elongation in the CD direction and high rigidity. Therefore, it is difficult to absorb the difference in folding length in the CD direction, and wrinkles are likely to occur.

Furthermore, in the technology described in Patent Document 1, the number of folding machines corresponding to the number of stacked bodies is arranged in sequence from the upstream to the downstream of the conveying line, which causes a problem of variation in quality, such as water absorbency, between the stacked sheets. After studying this problem in detail, the inventors concluded that the following may be the cause.

For example, a sheet sent from a folding machine arranged on the upstream side of the conveying line is crushed multiple times by multiple nip rolls arranged on the conveying line before being conveyed to the final point of the conveying line. In other words, such a sheet is crushed by more nip rolls, so the paper thickness becomes thinner. On the other hand, a sheet sent from a folding machine arranged on the downstream side of the conveying line is crushed only by nip rolls arranged downstream of the folding machine, so the paper thickness does not become as thin. In this way, the number of times the sheet is crushed by the nip rolls varies between clips, so it is thought that the above-mentioned variation in absorbency occurs between sheets. Normally, it is important for hand towels to have excellent absorbency, and they are often designed to be thick in order to increase absorbency, but it is thought that the variation in paper thickness causes a negative effect on absorbency as a result.

Furthermore, when the number of nip rolls and pull belts installed in an M/F processing machine is increased, the processing speed of the M/F processing machine does not increase, resulting in a problem of poor production efficiency. Also, when an attempt is made to increase the vertical strength of the sheet so that it can withstand high-speed processing, the paper becomes stiff, causing problems such as a deterioration in hand feel (wiping comfort, usability).

As such, in hand towel laminates produced by commonly used M/F processing machines, it is difficult to avoid a significant drop in production efficiency caused by the M/F processing machine while maintaining excellent ease of removal without the occurrence of wrinkles.

The present invention was made in consideration of these circumstances, and aims to provide a hand towel laminate that is highly absorbent, wrinkle-free, and easy to remove, even when processed using an M/F processing machine, and a method for manufacturing the hand towel laminate.

As a result of intensive research into achieving the above-mentioned object, the inventors have discovered and completed the present invention that a hand towel laminate is formed by folding sheets one by one and stacking them on top of each other, the sheets having a basis weight of 26.0 g/ ^m2 or more and 34.0 g/m2 or ^less , a paper thickness of 0.85 mm/10 plies or more and 1.20 mm/10 plies or less, a dry longitudinal tensile strength (DMDT) of 20.6 N/25 mm or more and 30.4 N/25 mm or less, a dry transverse tensile strength (DCDT) of 3.9 N/25 mm or more and 8.3 N/25 mm or less, and a D value measured by a TSA device of 1.2 mm/N or more and 2.4 mm/N or less.

In other words, the present invention is as follows.

(1)
A hand towel laminate in which sheets are folded one by one and stacked so as to overlap each other, the sheets having a basis weight of 26.0 g/m2 or ^more and 34.0 g/ ^m2 or less, a paper thickness of 0.85 mm/10 plies or more and 1.20 mm/10 plies or less, a dry machine direction tensile strength (DMDT) of 20.6 N/25 mm or more and 30.4 N/25 mm or less, a dry cross direction tensile strength (DCDT) of 3.9 N/25 mm or more and 8.3 N/25 mm or less, and a D value measured by a TSA device of 1.2 mm/N or more and 2.4 mm/N or less.
(2)
The hand towel laminate according to (1), wherein the sheet has a specific volume of 2.8 cm ³ /g or more and 4.0 cm ³ /g or less.
(3)
The hand towel laminate according to (1) or (2), wherein the ratio (DMDT/DCDT) of the dry machine direction tensile strength (DMDT) to the dry cross direction tensile strength (DCDT) of the sheet is 3.5 or more and 5.7 or less.
(4)
The hand towel laminate according to any one of (1) to (3), wherein the number of pairs in the hand towel laminate is 80 pairs or more and 200 pairs or less.
(5)
A method for producing a hand towel laminate as described in any one of (1) to (4), comprising: a lamination step in which the sheets are folded one by one by a folding section of a multi-folder folder while being transported by a conveyor, and stacked so that the sheets overlap each other to obtain an uncompressed laminate; and a compression step in which the uncompressed laminate is compressed by a compression processing section to obtain the hand towel laminate, wherein the compression processing section is disposed downstream of the conveyor from the folding section and includes pull belts disposed above and below the conveyor, and the compression step comprises a step of compressing the uncompressed laminate by passing it between the pull belts disposed above and below the conveyor after all of the sheets constituting the hand towel laminate have been stacked.
(6)
The method for producing a hand towel laminate according to (5), wherein the compression processing section is disposed downstream of the folding section.
(7)
The method for producing a hand towel laminate described in (5) or (6) is characterized in that the folding section includes a plurality of folding plate devices and at least one touch roll disposed above the conveyor between at least one of the adjacent folding plate devices, and the lamination step supports the sheet transported by the conveyor from above with the touch roll.
(8)
The method for producing a hand towel laminate described in (7) above, wherein the touch roll is a roughly cylindrical metal roll body having a diameter of 10 mm or more and 50 mm or less, a mass of 100 g or more and 1000 g or less, and is freely rotatable in the conveying direction of the conveyor.

According to the present invention, it is possible to provide a hand towel laminate that is highly absorbent, wrinkle-free, and easy to remove, even when processed using an M/F processing machine, and a method for manufacturing the hand towel laminate.

FIG. 1 is a perspective view illustrating a direction in which a sheet is taken out from a stack in an M/F processing machine. FIG. 2 is a conceptual diagram showing an example of a machine winder that can be used in the manufacturing method according to this embodiment. FIG. 3 is a conceptual diagram showing the configuration of a folding section of an M/F processing machine that can be used in the manufacturing method according to this embodiment. FIG. 4 is a perspective view of a folding plate device constituting the folding section of FIG. FIG. 5 is a schematic diagram for explaining an example of compression processing performed by a pull unit.

The following describes in detail the form for carrying out the present invention (hereinafter, simply referred to as the "present embodiment"). The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out with appropriate modifications within the scope of its gist.

In addition, in the drawings, the same elements are given the same reference numerals, and duplicate explanations are omitted. Furthermore, unless otherwise specified, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of the drawings are not limited to the ratios shown in the drawings.

Furthermore, in this specification, any term with "abbreviation" indicates the meaning of the term excluding "abbreviation" within the scope of common technical knowledge of a person skilled in the art, and includes the meaning itself excluding "abbreviation."

<Hand towel laminate>

The hand towel laminate according to this embodiment is a hand towel laminate in which sheets are folded one by one and stacked so as to overlap each other, and the sheets have a basis weight of 26.0 g/m2 or ^more and 34.0 g/ ^m2 or less, a paper thickness of 0.85 mm/10 plies or more and 1.20 mm/10 plies or less, a dry machine direction tensile strength (DMDT; dry machine direction tensile strength) of 20.6 N/25 mm or more and 30.4 N/25 mm or less, a dry cross direction tensile strength (DCDT; dry cross direction tensile strength) of 3.9 N/25 mm or more and 8.3 N/25 mm or less, and a D value measured by a TSA device of 1.2 mm/N or more and 2.4 mm/N or less.

As described below, the hand towel laminate of this embodiment is made by folding a single sheet and stacking the sheets on top of each other (see FIG. 1). The hand towel laminate of this embodiment can be removed one by one in succession in a pop-up style.

In this specification, the vertical direction refers to the flow direction when the hand towel is made, i.e., the MD (machine direction) direction. The horizontal direction refers to the direction perpendicular to the vertical direction, i.e., the CD (cross direction) direction.

The raw material for the sheet may be 100% pulp by mass, or may contain recycled paper materials. For example, recycled milk carton materials (MSF) may be used. When MSF is used, the blending rate is preferably 50% by mass or less.

The basis weight of the sheet is 26.0 g/m ² or more and 34.0 g/m ² or less. Preferably, it is 28.0 g/m ² or more and 32.0 g/m ² or less. The basis weight can be measured in accordance with JIS P 8124.

The thickness of the sheet is 0.85 mm/10 plies or more and 1.20 mm/10 plies or less. Preferably, it is 0.90 mm/10 plies or more and 1.10 mm/10 plies or less. The thickness can be measured under the conditions of JIS P 8111 (23±1°C, 50±2% relative humidity) using a thickness gauge (for example, Ozaki Seisakusho's upright dial thickness gauge "PEACOCK R1-B type") with a pressure of 3.7 kPa applied to the gauge.

By keeping the basis weight and paper thickness within the above ranges, the resulting hand towel will be highly absorbent, have a good feel when used, and be easy to remove.

The dry machine direction tensile strength (DMDT) of the sheet is 20.6 N/25 mm or more and 30.4 N/25 mm or less. Preferably, it is 22.6 N/25 mm or more and 28.4 N/25 mm or less. DMDT can be measured based on the tensile test method of JIS P 8113.

The dry cross tensile strength (DCDT) of the sheet is 3.9 N/25 mm or more and 8.3 N/25 mm or less. Preferably, it is 4.8 N/25 mm or more and 7.4 N/25 mm or less. DCDT can be measured based on the tensile test method of JIS P 8113.

By keeping the tensile strength in the vertical and horizontal directions within the above ranges, the resulting hand towel has a good feel and is comfortable to use, and when processed using an M/F processing machine, wrinkles are reduced and processing can be performed efficiently.

The D value of the sheet measured by a tissue softness measuring device (TSA device) is 1.2 mm/N or more and 2.4 mm/N or less. Preferably, it is 1.5 mm/N or more and 2.1 mm/N or less. This D value refers to the measured value of stiffness (D) expressed as the amount of deformation displacement in the vertical direction of the sample when a hand towel sample placed on the sample stage of the TSA device is pressed from above with a pressing pressure of 100 mN and 600 mN, respectively, without rotating the bladed rotor.

By keeping the D value within the above range, the resulting hand towel has a moderate rigidity, a good feel, and excellent usability, and when processed using an M/F processing machine, it can be processed with minimal wrinkles.

The specific volume of the sheet is preferably 2.8 ^cm3 /g or more and 4.0 ^cm3 /g or less, more preferably 3.0 ^cm3 /g or more and 3.7 ^cm3 /g or less, and even more preferably 3.2 ^cm3 /g or more and 3.4 ^cm3 /g or less. This specific volume can be calculated from the values of the basis weight and the paper thickness (paper thickness (mm/10 ply) ÷ basis weight (g/ ^m2 ) × 100). By setting the specific volume within the above range, a hand towel with high water absorbency and excellent usability can be obtained.

The ratio of the tensile strength in the longitudinal direction when dry to the tensile strength in the transverse direction when dry (longitudinal strength/transverse strength; DMDT/DCDT) is preferably 3.5 or more and 5.7 or less. More preferably, it is 4.0 or more and 5.0 or less. By keeping the longitudinal strength/transverse strength ratio within the above range, when processed using an M/F processing machine, the generation of wrinkles is reduced, processing can be performed with high production efficiency, and a hand towel with a good feel and excellent usability can be obtained.

The length of the sheet (the length parallel to the direction of pulling out) is not particularly limited, but is preferably 200 mm or more and 240 mm or less. The width of the sheet (the length perpendicular to the direction of pulling out) is not particularly limited, but is preferably 180 mm or more and 220 mm or less. By keeping the sheet length and width within the above ranges, a hand towel that is easy to use for wiping moisture off hands and has an excellent feel when used is obtained.

The number of sets in the hand towel laminate is preferably 80 sets or more and 200 sets or less. More preferably, it is 100 sets or more, and even more preferably, it is 130 sets or more. If there are 80 sets or more, the frequency of changing the carton or film pack can be reduced, further improving the usability. If there are 200 sets or less, the weight of one box or one pack is not too heavy, and there is no inconvenience in carrying it when purchasing or using it. The number of sets can be changed as appropriate depending on the size of the carton or film in which the hand towels are stored.

The packaging form of the hand towel laminate according to this embodiment is not particularly limited, and may be appropriately selected from, for example, cartons, film packaging (gusset packaging, pillow packaging, etc.), etc. Furthermore, when the hand towel laminate is made to be continuously removable in a pop-up manner, the shape of the removal opening is also not limited. For example, when the hand towel laminate is made into a carton, a window film may or may not be provided.

<Manufacturing method for hand towel laminate>

The hand towel laminate according to the present embodiment described above can be produced, for example, by the following manufacturing method.

The method for producing the hand towel laminate according to this embodiment includes (1) a lamination step in which the sheets are folded one by one by the folding section of a multi-folder folder while being transported by a conveyor, and the sheets are laminated so that they overlap each other to obtain an uncompressed laminate, and (2) a compression step in which the uncompressed laminate is compressed by a compression processing section to obtain the hand towel laminate. The compression processing section is preferably disposed downstream of the conveyor from the folding section and includes pull belts disposed above and below the conveyor, and the compression step is preferably a step in which, after all of the sheets constituting the hand towel laminate have been laminated, the uncompressed laminate is compressed by passing it between the pull belts disposed above and below.

(Papermaking process)

The sheets constituting the hand towel laminate can be obtained by papermaking using a papermaking machine. It is usually preferable to control the water flow rate/wire speed (J/W ratio) during papermaking to a range of 0.85 to 1.00.

For hand towels, wet strength is important, so it is preferable to add a wet strength agent (e.g., polyamine-polyamide epichlorohydrin type) to the paper stock slurry. It is also preferable to further add a dry strength agent to increase dry strength.

It is preferable to perform a creping process to impart softness, bulk, and water absorbency to the sheet. Creping is a method of mechanically compressing a sheet in the MD direction to form wavy wrinkles called "crepes," which can further improve bulk (feeling of bulk), softness, water absorbency, surface smoothness, aesthetics (crepe shape), elongation, etc. For example, a drying process is performed after papermaking, and crepes are formed during the drying process when the sheet is peeled off from the Yankee dryer with a creping doctor, and the crepe can be maintained by the difference in reel speed (the reel speed is slower than that of the Yankee dryer).

(Transportation process)

The sheets that make up the hand towel laminate are then transported to the next process using a crane or forklift. They may also be transported along the line by a conveyor.

(Calendar processing process)

Figure 2 is a conceptual diagram showing an example of a machine winder that can be used in the manufacturing method according to this embodiment.

The sheet obtained by the papermaking process is preferably subjected to a calendaring process. The calendaring process can be carried out, for example, by a machine winder 10 shown in FIG. 2. In this machine winder 10, a reel 11 wound in the reel part is set in the machine winder 10 and becomes a raw roll 14. At this time, the sheet is calendared on the second floor in the order of the first stack calendar machine 12 and the second stack calendar machine 13 (see arrow D2). Of course, calendaring may be carried out in only one stage, either the first stack calendar machine 12 or the second stack calendar machine 13. It is also possible to carry out calendaring using an on-machine calendar.

Although not shown, the original roll 14 may be embossed. If embossing is performed, it is preferable to perform calendaring before embossing.

(Lamination process)

Figure 3 is a conceptual diagram showing the configuration of the folding section of an M/F processing machine that can be used in the manufacturing method according to this embodiment, and Figure 4 is a perspective view of the folding plate device that constitutes the folding section of Figure 3.

First, in the stacking process, the sheets 100 are folded one by one so that they overlap. The folding form of the sheets 100 is not particularly limited as long as the sheets 100 can be taken out one by one in a pop-up manner, and can be, for example, a V fold or a Z fold. The folding of the sheets 100 can be performed by an M/F processing machine. The number of sets of the sheets 100 can be changed by adjusting the number of folding plate devices 20a, 20b, 20c, etc., of the folding section 20 described below.

The number of sets is not particularly limited, but is preferably 80 to 200 sets. More preferably, it is 100 sets or more, and even more preferably, it is 130 sets or more. If there are 80 sets or more, the frequency of changing cartons and film packs can be reduced, further improving the usability. If there are 200 sets or less, the weight of one box or one pack is not too heavy, and there is no inconvenience in carrying it when purchasing or using it.

For convenience, only three folding plate devices 20a, 20b, and 20c are shown in FIG. 3, but the folding section 20 of the M/F processing machine includes multiple folding plate devices 20a, 20b, 20c, etc. arranged on the conveying line. That is, each folding plate device 20a, 20b, 20c, etc. alternately folds the sheet 100 (sometimes called a "web") to form a set of folded laminates. For example, if there are 200 sets of hand towel laminates, 200 sets of sheets 100 will be laminated, and the number of folding plate devices 20a, 20b, 20c, etc. may be the same as the number of sets, 200, arranged on the conveying line.

Next, folding in one folding plate device 20a will be described. As shown in FIG. 4, in the folding plate device 20a, a plurality of sheets 100 cut to the product width are introduced, the unwinding direction is changed by a first guide roll 21, and then the sheets 100 are oriented by a second guide roll 22 so that a set of sheets 100 come into contact with each other. Finally, the sheets are guided by a folding plate 23 and folded together to form an uncompressed laminate 200, which is a long folded laminate (sometimes called a "laminate bundle").

Furthermore, according to this embodiment, the folding section 20 is provided with at least one touch roll 24 arranged above the conveyor 30 between at least one of the adjacent folding plate devices 20a, 20b, 20c, etc., and in the stacking process, it is preferable that the sheet conveyed by the conveyor 30 (for example, the uncompressed stack 200 in the case of Figures 3 and 4) is supported from above by the touch roll 24.

Unlike pinch rolls and nip rolls that actively press and feed the transported object (e.g., the sheet 100 or the uncompressed laminate 200, etc.), the touch roll 24 is a roll that supports the transported object by its own weight without applying pressure. In this embodiment, the sheets 100 are not compressed as much as possible until all the sets of sheets 100 are laminated (i.e., until the lamination process by the folding unit 20 is completed), so that the variation in physical properties such as the paper thickness, water absorbency, and feel of the sheets 100 can be suppressed. From this perspective, it is preferable to use the touch roll 24 in this embodiment. This allows the sheets 100 to be guided along the conveyor 30 with high stability without being compressed individually.

In FIG. 3, one touch roll 24 is arranged between folding plate device 20a and folding plate device 20b, one touch roll 24 is arranged between folding plate device 20b and folding plate device 20c, and a touch roll 24 is also arranged downstream of folding plate device 20c. However, in this embodiment, it is not necessary to provide a touch roll 24 between all adjacent folding plate devices, and it is preferable to provide one between at least one of them.

The touch rolls 24 are each a roughly cylindrical metal roll body, and preferably have a diameter of 10 mm or more and 50 mm or less. When the touch roll 24 is made of metal, the type of metal is not limited, and examples include aluminum, steel, iron, etc. In addition, the mass of each touch roll 24 is preferably 100 g or more and 1000 g or less. By using such dimensions and shapes, the touch roll 24 can guide the sheet 100 with high stability using only its own weight.

The touch roll 24 is preferably freely rotatable in the conveying direction of the conveyor 30 (the conveying direction of the uncompressed laminate 200, see arrow D3). This allows it to rotate freely, so that it can be synchronized with the conveying speed without generating unintended resistance or pressure during conveying, and it can be guided along the conveyor 30 with as little compression as possible until all the sets of sheets 100 are laminated (i.e., until the lamination process in the folding section 20 is completed).

The M/F processing machine can be configured to have multiple (e.g., three or more) PR (parent roll) stands in front of the folding section 20, and to pay out the web from the PR stands to the folding section 20. In addition, the configuration of the M/F processing machine may be modified as appropriate within the scope of the effect of this embodiment.

In this way, a set of stacks folded by one folding plate device 20a is folded so as to interlock with a set of stacks on the next folding plate device 20b arranged downstream on the conveyor 30. Then, a stack folded by the next folding plate device 20c is folded so as to interlock with this set of stacks. In this way, stacks folded by folding plate devices (not shown) arranged on the conveyor 30 are successively interlocked in sequence to obtain an uncompressed stack 200.

(Compression process)

Figure 5 is a schematic diagram illustrating an example of compression processing using a pull unit.

Next, the compression process and the compression processing unit that performs the compression process will be described with reference to FIG. 5. As the compression processing unit, for example, a pull unit (sometimes called a "pull belt") 40 can be used. In the compression process, the uncompressed laminate 200 can be compressed by passing it between an upper pull unit 41 and a lower pull unit 42 that are arranged above and below it.

The uncompressed laminate 200 (laminate bundle) is loaded into the pull unit 40 and compressed in the stacking direction by the upper pull unit 41 and the lower pull unit 42 to obtain a compressed laminate bundle. This is then cut to the product length (the longitudinal length of the hand towel) by a cut-off saw, log saw, or the like to obtain the hand towel laminate 300 (sometimes called a "clip," etc.).

The pull unit 40 has multiple sets of rolls (upper pull unit 41 and lower pull unit 42) arranged on the top and bottom. A belt such as a rubber belt is stretched between these upper and lower roll sets, and the upper and lower belts run at a predetermined speed (see arrows D4 and D5) by rotating rolls 45 and 46 with drive rolls 43 and 44, and the uncompressed laminate 200 is transported between the two belts, where it is compressed.

It is preferable that only one compression processing section is disposed downstream of the folding section 20. Specifically, it is preferable that the pull unit 40 is disposed downstream of the most downstream folding plate device (not shown) of the M/F processing machine. In this case, the pull unit 40 only needs to be disposed downstream of the most downstream folding plate device, and the number of units disposed is not particularly limited, but it is more preferable that there is only one. By controlling the placement conditions of the pull unit 40 in this manner, all of the sheets constituting the hand towel laminate 300 are compressed with the same compression force and number of compressions, so there is no variation in the paper thickness of each sheet 100, and as a result, variation in physical properties such as water absorbency can also be suppressed.

Although not shown, the resulting hand towel laminate 300 can be boxed and packaged by a subsequent cartoner or packaging machine to produce the final product.

As described above, according to this embodiment, even when processed by an M/F processing machine, it is possible to produce a hand towel laminate 300 that is highly absorbent, wrinkle-free, and easy to remove. Furthermore, depending on the embodiment, by controlling the physical properties of the hand towel laminate 300, such as basis weight, paper thickness, tensile strength in the longitudinal direction when dry, tensile strength in the lateral direction when dry, and D value measured by a TSA device, as well as the number of plies, it is possible to obtain a hand towel laminate that meets the required characteristics at a practical level without providing a pull belt or nip roll between the folders of the M/F processing machine, and it is also possible to produce a high-quality hand towel laminate with small quality differences between the sheets that are laminated.

In addition, the commonly used manufacturing method for the hand towel laminate 300 is a processing method using an M/F processing machine with a high processing speed. Even when the processing speed is set to a high speed to maintain high production efficiency, according to this embodiment, the dry longitudinal tensile strength (DMDT) of the sheet 100 is set high in order to withstand the processing speed, while the dry transverse tensile strength (DCDT) is set low (i.e., the DMDT/DCDT ratio is increased), thereby further improving the hand feel (e.g., wiping comfort and usability, etc.).

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples in any way.

<Making hand towel laminate>

Example 1
Using a manufacturing apparatus having the configuration shown in Figures 2, 3, 4, and 5, a single sheet was folded and laminated so as to overlap each other to produce a hand towel laminate 300. Specifically, for the folding section 20 of Figures 4 and 5, 120 folding plate devices 20a, 20b, 20c... were arranged on the line, and 40, 60, and 100 sets of touch rolls 24 (made of steel, diameter: 20 mm, mass: 700 g) having a substantially cylindrical shape were arranged on the line at three locations so as to touch the assembled clips. Specifically, first, paper was made under conditions of 70% by mass of pulp and 30% by mass of MSF to obtain a sheet 100. Next, the obtained sheet 100 was subjected to a calendaring process to keep the paper thickness within a specified range. Subsequently, a lamination process and a compression process were performed using an M/F processing machine. The laminated hand towels 300 were then cut with a log saw to obtain 120 sets (sheet length 220 mm, sheet width 198 mm).

(Examples 2 to 7, Comparative Examples 1 to 4)
A hand towel laminate was obtained in the same manner as in Example 1, except that the conditions were changed as shown in each table.

<Evaluation method>

(grammage)
The basis weight was measured in accordance with JIS P 8124.

(Paper thickness)
The paper thickness was measured under the conditions of JIS P 8111 (23±1° C., 50±2% relative humidity) using a thickness gauge (for example, an upright dial thickness gauge "PEACOCK R1-B type" manufactured by Ozaki Seisakusho) with a pressure of 3.7 kPa applied to the gauge.

(specific volume)
The specific volume was calculated from the basis weight and paper thickness.

(Tensile strength)
- Dry tensile strength of the sheet in the machine direction (DCDT)
The DCDT was measured for 1 ply based on the tensile test method of JIS P 8113 ("Strength - Vertical" in the table).
- Dry lateral tensile strength of the sheet (DCDT
The DCDT was measured for 1 ply based on the tensile test method of JIS P 8113 ("Strength - transverse" in the table).
The ratio of the dry tensile strength in the machine direction to the dry tensile strength in the cross direction of the sheet (machine strength/cross strength; DMDT/DCDT)
The strength was calculated based on the measured values of DCDT and DMDT described above ("Strength/aspect ratio" in the table).
These measurements were carried out under the conditions specified in JIS P 8111 (23±1° C., 50±2% relative humidity).

(D value measured by TSA device)
A hand towel sample was placed on the sample stage of a tissue softness measuring device (TSA; "Tissue Softness Analyzer" manufactured by emtec) and pressed from above with a pressing pressure of 100 mN and 600 mN without rotating the bladed rotor, and the measured stiffness (D) was expressed as the amount of deformation displacement of the sample in the up and down direction between pressing pressures of 100 mN and 600 mN, respectively.

(Evaluation of Total Water Absorbency (TWA))
For water absorption (TWA), first, the obtained hand towel is cut into a square test piece of 76×76 mm, and the dry mass (W1) is measured.Then, the test piece is immersed in distilled water for 2 minutes, and then one corner of the test piece is made to be the top of the upper side, and the top and two adjacent corners are supported and hung in an extended state (RH 100%), and the mass (W2) after leaving for 30 minutes is measured.Then, the value of (W2-W1) is calculated, and the value converted to 1 g of hand towel is taken as water absorption (TWA).

(Evaluation of Usability)
The hand towel laminate was used to wipe off moisture from hands after washing, and a sensory evaluation was conducted on the usability of the laminate by 60 people. Each person rated the usability on a scale of 1 to 5 based on the following criteria, and the usability was evaluated overall based on the following criteria.
(Criteria for judgment)
4 points or more and 5 points or less: When used for wiping hands, the material felt soft and had a particularly good feel to the touch.
3 points or more and less than 4 points: When used for wiping hands, the cloth felt soft and had a good feel to the touch.
Less than 3 points: When used for wiping hands, the cloth did not feel soft and felt rough to the touch.
(comprehensive evaluation)
"Excellent": The average score of the 60 reviewers was 4.0 points or more.
"Good": The average score of the 60 panelists was 3.0 or more and less than 4.0 points.
"X": The average score of the 60 evaluations was less than 3.0 points.

(Evaluation of processability)
A sheet was removed from the obtained hand towel laminate, and the state of wrinkles and creases was evaluated for processability according to the following criteria.
"Excellent": The creases were firmly formed, and wrinkles were observed in less than 10% of the total number of sets.
"◯": The creases were firmly formed, and wrinkles were observed in 10% or more and less than 20% of the total number of sets.
"X": Sheets in which the crease was not properly formed and wrinkles were observed in 20% or more of the total number of sets.

Table 1 shows the conditions and evaluation results for each example, and Table 2 shows the conditions and evaluation results for each comparative example.

From the above, it was confirmed that, according to this embodiment, even when processed using an M/F processing machine, a hand towel laminate with high water absorbency, no wrinkles, and excellent removal properties can be obtained.

10: Machine winder,
11: Reel,
12, 13: Calender machine,
14: Raw material roll,
20: folding section,
20a, 20b, 20c: folding plate device,
21: first guide roll,
22: second guide roll,
23: Folding plate,
24: Touch roll,
30: conveyor,
40: Pull unit (pull belt),
41: upper pull unit,
42: Lower pull unit,
43, 44: driving roll,
45, 46: Roll,
100: sheet,
200: uncompressed laminate,
300: Hand towel laminate,
C, D1, D2, D3, D4, D5: arrows,
S1, S2: Seat

Claims (6)

The hand towel laminate is made by folding the sheets one by one and stacking them on top of each other,
The sheet is
The basis weight is 26.0 g/m2 or ^more and 34.0 g/ ^m2 or less,
The paper thickness is 0.85 mm/10 plies or more and 1.20 mm/10 plies or less,
The dry machine direction tensile strength (DMDT) is 22.6 N/25 mm or more and 28.4 N/25 mm or less;
The dry cross tensile strength (DCDT) is 3.9 N/25 mm or more and 8.3 N/25 mm or less;
The D value measured by the TSA device is 1.5 mm/N or more and 2.1 mm/N or less.
Hand towel laminate. The specific volume of the sheet is 2.8 cm ³ /g or more and 4.0 cm ³ /g or less.
The hand towel laminate of claim 1 . The ratio (DMDT/DCDT) of the dry tensile strength in the machine direction (DMDT) to the dry tensile strength in the cross direction (DCDT) of the sheet is 3.5 or more and 5.7 or less;
The hand towel laminate of claim 1 or 2. The number of pairs of the hand towel laminate is 80 pairs or more and 200 pairs or less.
The hand towel laminate according to any one of claims 1 to 3. A method for producing the hand towel laminate according to any one of claims 1 to 4,
a stacking step of folding the sheets one by one by a folding unit of a multi-folder folder while conveying the sheets by a conveyor, and stacking the sheets so as to overlap each other to obtain an uncompressed stack;
a compression step of compressing the uncompressed laminate by a compression processing section to obtain the hand towel laminate;
Including,
The compression processing unit is disposed downstream of the conveyor from the folding unit, and includes pull belts disposed above and below the conveyor,
The compressing step includes a step of compressing the uncompressed laminate by passing the uncompressed laminate between the pull belts disposed above and below the pull belts after all of the sheets constituting the hand towel laminate have been laminated,
The compression processing section is disposed downstream of the folding section,
The folding section includes:
a plurality of folding plate assemblies;
At least one touch roll is disposed above the conveyor between at least one of the adjacent folding plate devices,
The touch roll supports the transported object by its own weight,
The lamination step includes supporting the sheet transported by the conveyor from above with the touch roll.
A method for producing a hand towel laminate. the touch roll is a metal roll body having a substantially cylindrical shape, a diameter of 10 mm or more and 50 mm or less, a mass of 100 g or more and 1000 g or less, and is freely rotatable in the conveying direction of the conveyor;
A method for producing the hand towel laminate according to claim 5 .

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