JP2022115660A - Cleaning wet sheet - Google Patents

Abstract

To provide a cleaning wet sheet that can reduce occurrence of wiping streaks in mopping by attaching the sheet to a cleaning tool with a head.SOLUTION: In a cleaning wet sheet 100, an embossment block row 31, in which a first embossment block 30 composed of a plurality of pieces of convex embossment 21 is arranged in series from a first side (a) to a second side (b), is continuously arranged in plurality from a third side (c) to a fourth side (d). Also, the convex embossment 21 is arranged to exist at least one on the line which is vertically extended from the third size (c) to the fourth size (d), so that the pieces of convex embossment 21 are to have overlapping allowances with each other. In addition, between respective embossment blocks 30, a non-embossed part 40 is provided in 25-50%, so that discharge of a chemical solution is improved to reduce occurrence of wiping streaks. Besides, while performance of wiping-off dirt is improved, increase in resistance for wiping can be suppressed.SELECTED DRAWING: Figure 2

Description

The present invention relates to a cleaning wet wipe.

Conventionally, embossing with convex portions on the cleaning surface of a cleaning wet sheet is known to improve dirt wiping performance, operability, visibility of dirt on the sheet, and the like (see, for example, Patent Document 1). ).

JP 2018-064723 A

However, in the cleaning wet sheet as disclosed in Patent Document 1, since the projections are arranged in series with the directions on the paper surface (for example, the direction of the long axis direction) aligned, wiping by the projections is not performed. A portion (so-called “wiping streak”) that was not there may be generated on the surface to be cleaned. A user who sees the wiping streaks decides that the chemical solution has run out and dried up, even though the chemical solution still remains in the sheet, and discards the sheet, resulting in unnecessary use of many sheets. I can put it away.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning wet sheet that can reduce the occurrence of wiping streaks when it is attached to a cleaning tool having a head portion to perform wiping.

The invention according to claim 1 is a cleaning wet sheet that is made by impregnating a base paper sheet with a chemical solution and is used by being attached to a cleaning tool having a head portion,
An embossed block formed by gathering a plurality of convex embossments that are convex embossments on the first surface of the cleaning wet sheet,
a plurality of the embossed blocks arranged continuously from a first side to a second side opposite to the first side to form an embossed block row;
A non-embossed part in which the embossing is not arranged is provided between the other adjacent embossed blocks,
A plurality of the embossed block rows are continuously arranged from a third side perpendicular to the first side to a fourth side opposite to the third side,
The non-embossed portion is provided so as to be 25% or more and 50% or less of the area of the cleaning wet sheet,
At least one convex emboss is arranged on a straight line extending perpendicularly to the fourth side from an arbitrary point on the third side.

The invention according to claim 2 is the cleaning wet sheet according to claim 1,
A concave embossing that is a convex embossing is provided on the second surface of the cleaning wet sheet,
The embossed block consists of a combination of a plurality of the convex embossing and the concave embossing,
At least one concave emboss is arranged on a line extending from an arbitrary point on the third side to the fourth side.

The invention according to claim 3 is the cleaning wet sheet according to claim 1 or 2,
The base paper sheet includes a hydrophobic fiber layer forming the surface of the sheet,
and a hydrophilic fiber layer sandwiched between the hydrophobic fiber layers,
A boundary region between the hydrophobic fiber layer and the hydrophilic fiber layer is characterized in that the fibers are entangled with each other.

The invention according to claim 4 is the cleaning wet sheet according to any one of claims 1 to 3,
The angle formed by the long axis direction of the embossing and the first direction perpendicular to the first side is 30° or more and 60° or less,
The embossed block is characterized by having a rhombus shape.

The invention according to claim 5 is the cleaning wet sheet according to any one of claims 1 to 4,
The embossing is characterized in that it has an elliptical shape and has a constricted portion at substantially the central portion in the major axis direction.

Advantageous Effects of Invention According to the present invention, it is possible to provide a cleaning wet sheet that can reduce the occurrence of wiping streaks when it is attached to a cleaning tool having a head portion for wiping.

1 is a perspective view of a cleaning tool to which a cleaning wet sheet according to the present embodiment is attached; FIG. 1 is a plan view showing a cleaning wet sheet according to an embodiment; FIG. FIG. 3 is a cross-sectional view of the III-III portion of FIG. 2; FIG. 11 is a plan view showing a cleaning wet wipe according to a modified example; FIG. 4 is a plan view showing an embossed pattern according to an example; FIG. 4 is a plan view showing an embossed pattern according to an example; It is a top view which shows the embossing pattern which concerns on a comparative example. It is a top view which shows the embossing pattern which concerns on a comparative example.

Hereinafter, a cleaning wet sheet 100 that is an embodiment of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples, and is determined based on the description of the scope of claims.
In the following description, the X direction, Y direction, and Z direction are defined as shown in FIG. In addition, in this specification, "~" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.

[Configuration of Embodiment]
FIG. 1 is a diagram showing a state in use of a cleaning wet sheet 100 of the present embodiment.
As shown in FIG. 1, the cleaning wet wipe 100 is replaceably attached to a cleaning tool 200 having, for example, a rectangular flat head portion 201 and a handle portion 202 attached to the upper surface of the head portion 201. It is a base paper sheet made by ply processing (laminating) a plurality of fiber aggregate base materials and impregnated with a chemical solution, and used for floor cleaning.

The cleaning wet sheet 100 as shown in FIG. 2 covers the bottom surface of the head portion 201 of the cleaning tool 200 to form a cleaning surface, and is folded along the longitudinal edge portion 201a of the head portion 201 of the cleaning tool 200 along the folding line S. It is bent and latched on the upper surface of the head portion 201 to be in a mounted state.
Note that the longitudinal edge portion 201a refers to an edge portion of the head portion 201 along the longitudinal direction. That is, it refers to the two longer edges of the four edges of the rectangular head portion 201 .

The fiber aggregate base material is a nonwoven fabric manufactured by bonding predetermined fibers by well-known techniques such as spunlace, air-through, airlaid, pointbond, spunbond, and needlepunch.

FIG. 3 is a cross-sectional view taken along line III--III in FIG.
As shown in FIG. 3, the cleaning wet sheet 100 has, for example, a three-layer structure in which the surface layers on both sides are hydrophobic fiber layers 11, 11 mainly made of hydrophobic fibers, and the middle layer is mainly made of hydrophilic fibers. It is the hydrophilic fiber layer 12 that becomes. In addition, the boundary regions between the fibers of the hydrophobic fiber layers 11, 11 and the fibers of the hydrophilic fiber layer 12 are configured such that the fibers are entangled with each other.

Therefore, the chemical liquid impregnated in the hydrophilic fiber layer 12 is less likely to be released to the surface to be cleaned adjacent to the hydrophobic fiber layer 11, and the chemical liquid can be selectively released to the floor surface, so that the chemical liquid is not effective for cleaning. Release can be suppressed.
Further, by constructing the structure so that the hydrophobic fibers and the hydrophilic fibers are entangled with each other, the retention of the chemical liquid can be further enhanced by the air retained in the entangled portions.

(hydrophilic fiber)
As hydrophilic fibers, natural fibers such as cotton, pulp and hemp, and regenerated fibers such as rayon and cupra can be used. etc. is preferably used.

(hydrophobic fiber)
Hydrophobic fibers include polyolefin fibers such as polyethylene (PE), polypropylene (PP) and polyvinyl alcohol, polyester fibers such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), and acrylic fibers. These can be used alone or in combination of two or more. The two or more types of conjugated fibers include a core with a relatively low melting point resin (low melting point resin) sheath, a core with a relatively high melting point resin (high melting point resin), and a low melting point resin and a high melting point resin. A side-back type in which the melting point resin is arranged in parallel in a predetermined direction can be used.

(weight)
In the case of the cleaning wet sheet 100 of the present invention, the basis weight is preferably about 30 g/m ² to 120 g/m ² , particularly about 60 g/m ² to 100 g/m ² . If the basis weight is less than 30 g/m ² , the dirt holding capacity is poor, and the cleaning wet sheet 100 tends to twist and become unstable during cleaning. On the other hand, if it exceeds 120 g/m ² , the flexibility becomes poor, and it becomes difficult to attach the cleaning wet sheet 100 to the cleaning tool 200 .

(CNF)
Cellulose nanofibers (CNF) can also be added to the cleaning wet wipes 100 .
CNF refers to fine cellulose fibers obtained by defibrating pulp fibers, and generally refers to cellulose fibers containing cellulose fine fibers with a fiber width of nanosize (1 nm to 1000 nm), but the average fiber width is Fibers of 100 nm or less are preferred. For the calculation of the average fiber width, for example, a certain number of number average, median, mode diameter (mode), etc. are used.

The CNF may be evenly impregnated in the thickness direction of the base-paper sheet, but it is preferable that the CNF content gradually increases from the center in the thickness direction of the base-paper sheet toward the front and back surfaces. . This is because the cleaning wet sheet 100 is thereby less likely to tear even if the cleaning surface or the like is strongly rubbed.

(Pulp fibers that can be used for CNF)
Pulp fibers that can be used to produce CNF include chemical pulps such as hardwood pulp (LBKP), softwood pulp (NBKP), bleached thermomechanical pulp (BTMP), stone ground pulp (SGP), pressure stone ground pulp (PGW ), refiner ground pulp (RGP), chemi ground pulp (CGP), thermo ground pulp (TGP), ground pulp (GP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), refiner mechanical pulp (RMP) Used paper manufactured from mechanical pulp, used tea paper, used kraft envelope paper, used magazine paper, used newspaper paper, used leaflet paper, used office paper, used corrugated paper, used white paper, used Kent paper, used imitation paper, used paper for certificates, used waste paper, etc. Pulp, deinked pulp (DIP) obtained by deinking waste paper pulp, and the like. These may be used singly or in combination of two or more as long as the effects of the present invention are not impaired.

(CNF defibration method)
Examples of defibration methods used for CNF production include mechanical methods such as high-pressure homogenizer method, microfluidizer method, grinder grinding method, bead mill freeze pulverization method, and ultrasonic defibration method. is not limited to
In addition, CNF that has been mechanically treated (not denatured) by the above fibrillation method or the like, that is, CNF that is unmodified with a functional group, is modified with a functional group such as a phosphate group or a carboxymethyl group. Due to its high thermal stability, it can be used for a wider range of applications, but it is also possible to use CNF modified with a functional group such as a phosphate group or a carboxymethyl group in the present invention.
Further, for example, pulp fibers subjected to defibration treatment by a mechanical method may be subjected to chemical treatment such as carboxymethylation, or may be subjected to enzyme treatment. Examples of chemically treated CNF include iCNF (individualized CNF) (single nanocellulose) with a diameter of 3 nm to 4 nm, such as TEMPO-oxidized CNF, phosphate-esterified CNF, and phosphite-esterified CNF. be done.
In addition, CNF that has undergone only chemical treatment or enzyme treatment, or CNF that has been subjected to chemical treatment or enzyme treatment and then subjected to defibration treatment by a mechanical method may be used.

[Chemical solution]
Further, the cleaning wet wipe 100 of the present embodiment is impregnated with a prescribed chemical solution containing auxiliary agents such as glycol ethers, aqueous detergents, preservatives, disinfectants, lower alcohols, organic solvents, and the like. The chemical solution is impregnated in an amount of 100% to 500% by mass, preferably 150% to 300% by mass, based on the mass of the base paper sheet that is the base material of the cleaning wet sheet 100 .
The dried base paper sheet is impregnated with the chemical solution, and the chemical solution impregnated in the hydrophilic fiber layer 12 is released from the hydrophobic fiber layer 11 on the front or back surface when the cleaning wet sheet 100 is used.

[Emboss]
Further, as shown in FIGS. 1 and 2, the wet cleaning sheet 100 is provided with embossments 20 that are portions of the sheet compressed in the Z direction.
For example, as shown in FIG. 2, the embossing 20 is formed in a so-called gourd shape, which has an elongated elliptical shape that is short in one direction and narrow in width in a plan view, and has a constricted portion at approximately the center in the major axis direction. there is The shape of the emboss 20 is not limited to this. For example, various shapes such as a polygon, or a shape combining each shape may be used. is preferred.

Such embossing 20 can be formed by thermal embossing under conditions of, for example, a temperature of 80° C. to 200° C. and an embossing pressure of 0.2 MPa to 1.0 MPa. When the embossing 20 is formed by thermal embossing, as the convex embossing roll, at least the outer peripheral surface can be made of carbon steel, stainless steel, polypropylene, or cured resin such as ABS (Acrylonitrile Butadiene Styrene) resin. Among them, it is preferable to use stainless steel from the viewpoint of durability and heat resistance.
In addition, when the embossing is performed by thermal embossing, it is preferable to perform the embossing before the step of impregnating the cleaning wet sheet 100 with the chemical liquid, in order to easily impart the concave-convex shape.

(convex embossing, concave embossing)
The embossment 20 includes a convex embossment 21 that is convex on the upper side in the Z direction (the first surface side of the cleaning wet sheet 100) and a convex shape on the lower side (the second surface side of the cleaning wet sheet 100) ( That is, a concave emboss 22 is formed on the upper side in the Z direction. In addition, in each figure, the convex embossment 21 is indicated by a solid line, and the concave embossment 22 is indicated by a broken line.

The convex embossment 21 is 5 mm to 10 mm, preferably 6 mm to 8 mm, in the long axis direction, 2 mm to 5 mm, preferably 3 mm to 4 mm in the short axis direction perpendicular to the long axis direction, and in the Z direction (middle part ( The height from (to be described later)) is 0.5 mm to 2 mm, preferably 0.7 mm to 1.5 mm. The concave embossment 22 is formed upside down and in substantially the same shape as the convex embossment 21 in a cross-sectional view, and is formed in a shape that protrudes downward in the Z direction.

(middle part)
Intermediate portions are formed between the embossments 20 formed on the cleaning wet sheet 100 . Since the intermediate portion is a portion where the embossing 20 is not formed, it is positioned lower than the convex embossing 21 and higher than the concave embossing 22 in the Z direction.

[Embossed pattern]
In the cleaning wet wipe 100 according to the present embodiment, for example, as shown in FIG. A rhombus-shaped first embossed block 30 consisting of a combination of convex embossing 21 and concave embossing 22 having an angle of . 31, the embossed block row 31 is continuously arranged from the third side c to the fourth side d, and the adjacent first embossed block row 31 and the second embossed block row 31 The first embossed blocks 30 in the first embossed block row 31 are aligned with the adjacent second embossed blocks 30 in the second embossed block row 31 in the second direction perpendicular to the first direction (in FIG. 2 Y direction), and at least one convex embossment 21 and concave embossment 22 exist on a straight line extending vertically from an arbitrary point on the third side c to the fourth side d placed.

(non-embossed part)
Further, as shown in FIG. 2, between the adjacent embossed blocks 30, the cleaning wet sheet 100 is not compressed in the Z direction, and a non-embossed portion 40 having nap is provided. there is

The non-embossed portion 40 is formed by designing the convex embossing roll that forms the embossed portion 20 so as to remove the shape of the non-embossed portion 40, or by compressing the embossed portion 20 to the extent that the nap remains. It can be formed by relatively light compression.
Such a non-embossed portion 40 is provided in 25% to 50% of the area of the cleaning wet sheet 100, thereby reducing the occurrence of wiping streaks and providing the cleaning wet sheet 100 with excellent wiping properties. can do.

When the cleaning wet sheet 100 is attached to the cleaning tool 200 for wiping, it is moved substantially vertically in the X direction or the Y direction, but as shown in FIG. , there is a risk that wiping streaks may easily occur depending on the angle at which the cleaning wet sheet 100 is moved. Therefore, it is more desirable to arrange the embossing blocks 30 so that the non-embossed portions 40 are not aligned.

[Effect of the invention]
Normally, when the cleaning tool 200 having the head part 201 performs wiping, it is moved in the first direction or the second direction. When the cleaning wet sheet 100 arranged so that at least one convex embossment 21 exists on a straight line extending vertically from the fourth side d, at least in the second direction (in FIG. 2 When wiping is performed in the Y direction), the convex embossments 21 overlap with each other, so the occurrence of wiping streaks can be reduced.

In addition, without providing the emboss 20 on the entire surface of the cleaning wet sheet 100, the non-embossed portion 40 is provided between the embossed blocks 30 at 25% to 50% of the area of the cleaning wet sheet 100. When wiping with the cleaning wet sheet 100, since the convex embossments 21 that protrude from the non-embossed portions 40 receive a greater pressure, the release of the chemical solution is improved, and the occurrence of wiping streaks can be further reduced. .
In addition, since the convex embossing 21 receives a higher pressure, the scraping property of the convex embossing 21 is improved, and dust tends to accumulate in the non-embossed portion 40, so that the dust collecting property can be enhanced. In addition, even if the scraping property of the convex embossment 21 and the dirt collecting property of the cleaning wet sheet 100 are improved, the non-embossed portion 40 is less likely to contact the surface to be cleaned due to the convex embossment 21, so the wiping resistance is increased. can be suppressed.

In addition, since the cleaning wet sheet 100 has a three-layer structure in which the hydrophilic fiber layer 12 is sandwiched between the hydrophobic fiber layers 11, 11, the chemical liquid held in the hydrophilic fiber layer 12 is selectively covered. It will be released onto the surface to be cleaned. In addition, the air held by the intertwined portion of the hydrophobic fiber layer 11 and the hydrophilic fiber layer 12 can further enhance the retention of the chemical solution.

In addition, the embossed block 30 is a diamond-shaped one having embossings 20 such that the angle between the first direction and the major axis direction is 30° to 60°, so that the first side a to the second side When a plurality of embossed block rows 31 arranged continuously up to the side b are arranged continuously from the third side c to the fourth side d, the embossed blocks 30 inevitably form a part of the cleaning wet sheet 100. It is arranged so as to be shifted with respect to the first direction. In addition, when the user performs wiping, the angle at which the cleaning wet sheet 100 is moved has a margin.

In addition, the embossing 20 has an elliptical shape and has a constricted portion at substantially the central portion in the long axis direction, so that the dirt scraping performance can be enhanced.

[Modification]
In addition, it goes without saying that the specific details of the structure and the like can be changed as appropriate.

For example, in the above description, the cleaning wet sheet 100 illustrated the embossed block 30 composed of a combination of the convex embossments 21 and the concave embossments 22 , but the embossed block 30 may include at least the convex embossments 21 .
However, by providing the recessed embossment 22, the cleaning wet sheet 100 can be turned over and used, and the cleaning area can be further expanded, which is preferable.

1 and 2 illustrate the rhombus-shaped embossed block 30 made up of embossments 20 that form an angle of 30° to 60° between the first direction and the major axis direction. The shape is not limited to this. For example, the embossed block 30 may be an embossed block 30 having an emboss 20 with an angle of 0° or 90° between the first direction and the longitudinal direction.

1 and 2, the convex embossing 21 and the concave embossing 22 in each embossing block 30 are exemplified so that the angles formed by the major axis direction and the first direction are the same. However, as shown in FIG. 4, the first embossing block 30 and the second embossing block 30 adjacent to the first embossing block 30 are oriented in the major axis direction of the convex embossing 21 and the concave embossing 22 . The convex embossments 21 and the concave embossments 22 may be arranged in a direction different from the longitudinal direction.
Further, the angles of the convex embossing 21 and the concave embossing 22 in the first embossing block 30 may be different from each other.

Further, the chemical liquid impregnated in the cleaning wet sheet 100 can be changed according to its application.
Also, although the cleaning wet sheet 100 has a three-layer structure, it is not limited to this.
Further, in each figure, the first side a and the second side b are the short sides of the cleaning wet sheet 100, and the third side c and the fourth side d are the long sides of the cleaning wet sheet 100. However, it is not limited to this.

Further, in each drawing, the convex embossment 21 and the concave embossment 22 are both substantially the same gourd shape in plan view, but the convex embossment 21 and the concave embossment 22 may have different shapes.

However, in any of the embossed patterns described above, it is preferable that the convex embossments 21 and the concave embossments 22 are arranged substantially symmetrically on the first surface and the second surface of the cleaning wet sheet 100 . By doing so, the first surface and the second surface of the cleaning wet sheet 100 have the same degree of cleaning function, and the cleaning area per sheet can be increased.

Next, the results of evaluation of preferred configurations for examples of the present invention and comparative examples will be described. EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these.

[Sample creation]
First, two hydrophobic fiber layers with a basis weight of 40 g/m ² to 50 g/m ² and consisting of 80% PET and 20% PP/PE binder, and 70 pieces of pulp with a basis weight of 40 g/m ² to 50 g/m ² % and 30% PPSB, and entangled by a hydroentangling method so that both sides of the hydrophilic fiber layer are sandwiched between the hydrophobic fiber layers. One base paper sheet was created by cutting it so that it would be.
Next, the base paper sheet was subjected to hot embossing under the conditions of a temperature of 95° C. and an embossing pressure of 0.4 MPa so as to obtain the embossed patterns of Example 1-3 and Comparative Example 1-3 below to prepare test sheets. .

(Example 1; non-embossed portion 25%)
As shown in FIG. 2, a rhombus shape consisting of a combination of gourd-shaped convex embossments 21 and concave embossments 22 such that the angle between the first direction (the X direction in FIG. 2) and the major axis direction is 30°. An embossed block row 31 formed by continuously arranging a plurality of first embossed blocks 30 from the first side a to the second side b opposite to the first side a from the third side c A plurality of them are continuously arranged up to the fourth side d. At this time, in the first embossed block row 31 and the second embossed block row 31 adjacent to each other, the first embossed block 30 in the first embossed block row 31 is adjacent to the second embossed block row 31 At least one convex embossment 21 exists on a line that overlaps the second embossing block 30 in the first direction and extends perpendicularly to the fourth side d from an arbitrary point on the third side c. The embossed portions 20 were arranged so as to form the embossed blocks 30, and the non-embossed portions 40 were provided between the embossed blocks 30 so as to occupy 25.0% of the area of the base paper sheet.

(Example 2; non-embossed portion 37.5%)
As shown in FIG. 5A, the non-embossed portion 40 was provided so as to occupy 37.5% of the area of the base paper sheet.
Other conditions are the same as in Example 1.

(Example 3; non-embossed portion 50%)
As shown in FIG. 5B, the non-embossed portion 40 was provided so as to occupy 50.0% of the area of the base paper sheet.
Other conditions are the same as in Example 1.

(Comparative Example 1; non-embossed portion 0%, serial arrangement)
As shown in FIG. 5C , gourd-shaped convex embossments and concave embossments whose longitudinal direction is parallel to the first direction are alternately arranged on the entire surface of the base-paper sheet to form a non-embossed portion 40 . Created a test sheet without
(Comparative Example 2; non-embossed portion 0%, zigzag shape)
It is a gourd-shaped embossing, and a plurality of first convex embossings and second convex embossments having different directions in the long axis direction are provided. A part of the convex embossing overlaps and is arranged so as to be shifted in the long axis direction, and the second convex embossments adjacent to each other in the short axis direction are partially overlapped in the short axis direction, and Arranged so as to be offset in the longitudinal direction.
Such a plurality of first convex embossings and second convex embossings are arranged adjacent to each other so that the long axis direction forms a substantially right angle, and from the first side a of the base paper sheet to the second side facing the first side a were arranged continuously so as to face the side b.
Also, concave embossments were arranged in the same embossing pattern as the convex embossments so as to alternate with the convex embossments, and a test sheet without non-embossed portions 40 as shown in FIG. 5D was prepared.
(Comparative Example 3; non-embossed portion 100%)
A test sheet having only a non-embossed portion 40 was prepared without embossing.

The test sheets of Example 1-3 and Comparative Example 1-3 were impregnated with 300% by mass of each dry weight of a chemical solution containing an aqueous detergent, an antiseptic, a disinfectant, and alcohol. Wet sheets of -3 and Comparative Example 1-3 were prepared, and each was attached to a cleaning tool having a flat head portion of 250 mm × 100 mm to prepare a wiper with a wet sheet of Example 1-3 and Comparative Example 1-3. did.

The following Test 1-3 was conducted using the wipers with wet sheets of Example 1-3 and Comparative Example 1-3.

[Test 1. Wipe streak test]
(1) A wiper with a wet sheet on which a total weight of 400 g is placed is placed on the right end of the blackboard so that the head faces the wiper.
(2) Push the weight and wiper with wet sheet from the right end to the left end of the blackboard to move 300 mm.
(3) Regarding the wiping streaks that are created, the state where there are almost no wiping streaks on the cleaning surface (wet area is about 90% to 100% of the entire cleaning surface) is 〇, and the state where wiping streaks are slightly generated ( The wetted area was about 80% to 90% of the entire cleaning surface), and the state in which many wiping streaks were generated (the wetted area was 80% or less of the entire cleaning surface) was evaluated visually.

[Test 2. Wiping performance test]
(1) On a 480 mm × 320 mm stainless steel plate, 15 ml of pseudo-dirt mixed with beef tallow: olive oil: chloroform: fluorescent paint = 12.5: 12.5: 74.4: 0.6 (mass ratio) After dripping and spreading, it is dried for 5 minutes with a hot air dryer (temperature of 60° C.), and the weight of the stainless steel plate is measured.
(2) A wiper with a wet sheet on which a total weight of 500 g is placed is placed on the right end of the stainless steel plate so that the head faces directly.
(3) Push the weight and wiper with wet sheet from the right end to the left end of the stainless steel plate, dry only the stainless steel plate again with a hot air dryer (temperature 60°C) for 5 minutes, and measure the weight.
(4) From the difference between the weight of the stainless steel plate before the test measured in (1) and the weight of the stainless steel plate after the test measured in (3), the wiping amount of each cleaning wet sheet is calculated.
(5) Repeat the operations (1) to (4) twice to calculate the average wiped amount.

[Test 3. Wiping resistance test]
(1) A wiper with a wet sheet on which a total weight of 500 g is placed is placed on the composite flooring so that the head portion faces directly.
(2) A hole is made in the head connecting portion of the wiper body, and a push-pull gauge (DS2-200N manufactured by Imada Co., Ltd.) is attached to the hole.
(3) Measure the maximum resistance value when the wiper with a wet sheet equipped with a push-pull gauge is pulled by 50 cm.
(4) Perform the operation of (3) five times and calculate the average value of the wiping resistance.

The results of Tests 1-3 are shown in Table I.

[evaluation]
Comparing the results of Test 1, Example 1-3, in which the non-embossed portion 40 is provided, can reduce the occurrence of wiping streaks compared to Comparative Examples 1 and 2, in which the non-embossed portion 40 is not provided. I understand. It is believed that this is because the non-embossed portion 40 provided increased the pressure applied to the convex embossment 21 and enhanced the releasability of the chemical solution.
On the other hand, when comparing Examples 1-3 and Comparative Example 3, as the proportion of the non-embossed portion 40 increased, the occurrence of wiping streaks increased, although slightly. This is presumably because as the ratio of the non-embossed portions 40 increases, the number of convex embossments 21 decreases accordingly, the contact area with the blackboard decreases, and the releasability of the chemical solution decreases.

Further, when the results of Test 2 are compared, the wiping amount is greater in Example 1-3 in which the non-embossed portion 40 is provided than in Comparative Examples 1 and 2 in which the non-embossed portion 40 is not provided. It can be seen that the wiping performance is improved.
On the other hand, when comparing Examples 1-3, Example 1, in which 25% of the non-embossed portions 40 are provided, can wipe off the most dirt, and the amount of dirt wiped off decreases as the number of non-embossed portions 40 increases. I understand. This is presumably because, as described above, as the ratio of the non-embossed portions 40 increases, the number of convex embossments 21 decreases accordingly, resulting in reduced chemical liquid release and dirt scraping properties.

In addition, when comparing the results of Test 3, only Comparative Example 3, in which the embossed portion 20 was not provided on the entire surface, had a strong wiping resistance, but Comparative Examples 1 and 2, in which the non-embossed portion 40 was not provided, and the non-embossed portion. There was no significant difference in wiping resistance between Example 1-3 in which 40 was provided.
This is presumably because the non-embossed portion 40 is less likely to contact the surface to be cleaned, and therefore the wiping resistance of the cleaning wet sheet 100 as a whole does not change much.

100 cleaning wet sheet 11 hydrophobic fiber layer 12 hydrophilic fiber layer 20 emboss 21 convex emboss 22 concave emboss 30 embossed block 31 embossed block row 40 non-embossed portion 200 cleaning tool 201 head portion a first side b second side c third side d fourth side

Claims (5)

A cleaning wet sheet made by impregnating a base paper sheet with a chemical solution and used by being attached to a cleaning tool having a head portion,
An embossed block formed by gathering a plurality of convex embossments that are convex embossments on the first surface of the cleaning wet sheet,
a plurality of the embossed blocks arranged continuously from a first side to a second side opposite to the first side to form an embossed block row;
A non-embossed part in which the embossing is not arranged is provided between the other adjacent embossed blocks,
A plurality of the embossed block rows are continuously arranged from a third side perpendicular to the first side to a fourth side opposite to the third side,
The non-embossed portion is provided so as to be 25% or more and 50% or less of the area of the cleaning wet sheet,
A cleaning wet sheet, wherein at least one of the convex embossments is present on a straight line extending perpendicularly to the fourth side from an arbitrary point on the third side. . A concave embossing that is a convex embossing is provided on the second surface of the cleaning wet sheet,
The embossed block consists of a combination of a plurality of the convex embossing and the concave embossing,
2. The cleaning method according to claim 1, wherein at least one concave embossment is present on a line extending from an arbitrary point on the third side to the fourth side. Wet sheet for. The base paper sheet includes a hydrophobic fiber layer forming the surface of the sheet,
and a hydrophilic fiber layer sandwiched between the hydrophobic fiber layers,
The cleaning wet sheet according to claim 1 or 2, wherein the fibers of the hydrophobic fiber layer and the hydrophilic fiber layer are intertwined in a boundary region. The angle formed by the long axis direction of the embossing and the first direction orthogonal to the first side is 30° or more and 60° or less,
The cleaning wet sheet according to any one of claims 1 to 3, wherein the embossed blocks are diamond-shaped. The cleaning wet sheet according to any one of claims 1 to 4, wherein the embossment has an elliptical shape and has a constricted portion in a substantially central portion in the major axis direction.

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