Paper Industrial Wipers

Abstract

To provide a paper-made industrial wiper which has the water absorption property (water absorption amount, water absorption speed per unit weight), wiping performance, excellent tactile and toughness.SOLUTION: There is provided a paper-made industrial wiper that is integrated by plying up base paper whose basis weight is between 18.7 g / m2 and 26.7 g / m2, paper thickness is between 0.78 mm / 10 plies and 1.25 mm / 10 plies, crepe height is between 22.0 μm and 41.5 μm, crepe number is between 15 / 6 mm and 32 / 6 mm, D value by a tissue softness measurement device TSA is between 1.2 mm / N and 2.8 mm / N to 2 plies or greater and 6 plies or less, and performing embossing on the base paper.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to embossed paper industrial wipers. [Background technology]

[0002] Industrial wipers (hereinafter also referred to as paper industrial wipers) made from pulp or recycled paper (cellulose only, excluding nonwoven fabric) are known.

[0003] Most products on the market are 2 to 6 ply, and come in a variety of embossing shapes (matched embossing, pin embossing, etc.) and product forms (pop-up type, quarter-fold type, handy type, etc.).

[0004] The qualities required for paper industrial wipers include absorbency (high water absorption capacity and fast water absorption speed), durability, wiping ability, and a pleasant feel.

[0005] For example, Patent Document 1 discloses prior art documents for such paper industrial wipers. The fibers are 100% pulp, which contains 70 to 100 parts by weight of NBKP (softwood kraft pulp), and the pulp is made by adding 0.125 to 1.25 parts by weight of a wet strength agent and 0.01 to 0.5 parts by weight of a softener per 100 parts by weight of the fibers. The wipes are calendered, have a softness (handle-ometer method: in accordance with JIS L 1096E) of 3.0 to 12.0 g, and have an MMD of 7.0 to 20.0 on each side. The wipes are stored in a cut-off state for each use, and each cut-off and stored paper wipe is folded in half with the side with the larger mean deviation of the coefficient of friction (MMD) of the wipe surface inside, and the folded sides are stacked so that they are in contact with each other and interlock with each other, and are removed by popping up when used. Patent Document 2 also describes a laminate in which the number of stacked paper sheets is 4 or more and 8 or less, and at least one of the paper sheets in the surface layer of the laminate has a basis weight of 14.0 gsm to 19.0 gsm, an opening rate of the paper sheet is 2.1% to 7.5%, and the water absorption of the laminate is 300 g / m 2 ~760g / m 2 An industrial wiping sheet characterized by: [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5366596 [Patent Document 2] Patent No. 5978100 Summary of the Invention [Problem to be solved by the invention]

[0007] However, for industrial paper wipers, as the basis weight of each ply of base paper increases, there are more hydrogen bonds between the pulp, and the yield of paper strength agents improves, resulting in increased strength (durability) and faster water absorption when wiping away moisture. However, while this has the advantage of increasing the density of the base paper, it also has the disadvantage of reducing the amount of water absorbed per unit weight (hereinafter also referred to as TWA), making it difficult to emboss paper with a high basis weight and high strength in a processing machine, resulting in paper with a low embossing height resulting in reduced water absorption per unit weight, making the paper less elastic and resulting in poor wiping properties, and paper with high strength tends to be stiff and therefore has a poor feel to the touch.

[0008] For this reason, it has been difficult to achieve a good balance of absorbency (amount of water absorbed per unit weight, water absorption speed), wiping performance, good feel, and durability, all of which are required for industrial wipers.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a paper industrial wiper that combines water absorbency (amount of water absorbed per unit weight, water absorption speed), wiping performance, a good feel, and durability. [Means for solving the problem]

[0010] The inventors have conducted extensive research and have found that by adjusting the basis weight, paper thickness, crepe height, crepe number and D value measured by a tissue softness analyzer (TSA) of the base paper to appropriate ranges, plying up a predetermined number of sheets of the base paper, and embossing and integrating them, it is possible to produce a paper industrial wiper that combines water absorbency (amount of water absorbed per unit weight, water absorption speed), wiping performance, a good feel and durability, and have thus completed the present invention.

[0011] (1) The first aspect of the present invention is a paper having a basis weight of 18.7 g / m 2 More than 26.7g / m 2 The following refers to an industrial paper wiper characterized by being made by plying together base paper having a paper thickness of 0.78 mm / 10 plies or more and 1.25 mm / 10 plies or less, a crepe height of 22.0 μm or more and 41.5 μm or less, a number of crepes of 15 / 6 mm or more and 32 / 6 mm or less, and a D value of 1.2 mm / N or more and 2.8 mm / N or less as measured by a tissue softness measuring device TSA, into 2 plies or less and embossing the plies to form an integrated unit.

[0012] (2) A second aspect of the present invention is the paper industrial wiper according to (1), characterized in that the number of plies is 3 or 4.

[0013] (3) A third aspect of the present invention is the paper industrial wiper according to (1) or (2), characterized in that the embossing is a pin embossing.

[0014] (4) A fourth aspect of the present invention is a paper industrial wiper as described in (3), characterized in that the height of the pin embossed portion is 300 μm or more and 850 μm or less.

[0015] (5) A fifth aspect of the present invention is a paper industrial wiper according to (3) or (4), characterized in that the area ratio of the pin embossing on the wiper is 0.42% or more and 1.40% or less.

[0016] (6) The sixth aspect of the present invention is a paper industrial wiper according to any one of (1) to (5), characterized in that the pitch between the nearest embossments is 1.0 mm or more and 3.8 mm or less.

[0017] (7) A seventh aspect of the present invention is a paper industrial wiper according to any one of (1) to (6), wherein the wiper has a basis weight of 56.1 g / m 2 More than 106.8g / m 2 It is characterized by the following:

[0018] (8) The eighth aspect of the present invention is a paper industrial wiper according to any one of (1) to (7), characterized in that the paper thickness of the wiper is 0.40 mm / product ply number or more and 0.81 mm / product ply number or less.

[0019] (9) A ninth aspect of the present invention is a paper industrial wiper according to any one of (1) to (8), characterized in that the wiper has a dry longitudinal tensile strength of 31.4 N / 25 mm or more and 73.2 N / 25 mm or less, and a dry transverse tensile strength of 7.8 N / 25 mm or more and 26.2 N / 25 mm or less, based on JIS P 8113.

[0020] (10) A tenth aspect of the present invention is a paper industrial wiper according to any one of (1) to (9), characterized in that the wiper is folded into four. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a paper industrial wiper that combines water absorbency (amount of water absorbed per unit weight, water absorption speed), wiping performance, a good feel, and durability. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a cross-sectional view of an embossed portion of the paper industrial wiper according to the present embodiment. [Figure 2] FIG. 2 is a plan view of the embossed portion of the paper industrial wiper according to the present embodiment, viewed from the surface. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. 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 by appropriately modifying it within the scope of its gist.

[0024] In the drawings, the same elements are denoted by the same reference numerals, and redundant explanations will be 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 those shown in the drawings.

[0025] <Paper industrial wipers> As shown in the cross-sectional view of Figure 1, the industrial paper wiper 1 according to this embodiment is made by plying (stacking) two to six plies of base paper 10 together and embossing (applying embossments 20). In this case, the number of plies is preferably three or four. By using three or four plies, the industrial paper wiper 1 has excellent strength and water absorption speed as a paper wiper, is easy to emboss, and has excellent water absorption per unit weight. The longitudinal dimension of the paper industrial wiper 1 is preferably 330 mm to 390 mm, and the width dimension is preferably 310 mm to 350 mm. The product form of the paper industrial wiper 1 is not particularly limited as long as it is a form used in ordinary industrial wiper products, such as a pop-up type, a four-fold type, or a handheld type, but a four-fold type is particularly preferred. When folded in four, the water absorption rate is particularly good when used to wipe moisture off an object.

[0026] The basis weight of paper industrial wiper 1 is 56.1 g / m 2 More than 106.8g / m 2 Preferably, it is 60.0 g / m or less. 2 More than 101.2g / m 2 By setting the basis weight within the above range, the paper industrial wiper 1 can be made to have both water absorbency (amount of water absorbed per unit weight, water absorption speed) and durability. The basis weight is measured in accordance with JIS P 8124.

[0027] The paper thickness of the industrial paper wiper 1 is preferably 0.40 mm / product ply number or more and 0.81 mm / product ply number or less, and more preferably 0.47 mm / product ply number or more and 0.74 mm / product ply number or less. By setting the paper thickness within the above numerical range, the industrial paper wiper 1 can be made to have both water absorbency (amount of water absorbed per unit weight, water absorption speed) and durability. The "product ply number" unit of paper thickness refers to measuring the paper thickness without increasing or decreasing the plies of the paper industrial wiper 1 product (processed paper industrial wiper 1, not base paper 10). Paper thickness can be measured using a thickness gauge (for example, Ozaki Seisakusho's "PEACOCK" dial thickness gauge) under JIS P 8111 conditions (23±1°C, 50±2% relative humidity) with a measurement load of 3.7 kPa and a probe diameter of 3 mm, by placing a sample (paper industrial wiper 1) between the probe and the measuring table, and reading the gauge when the probe is lowered at a speed of 1 mm per second or less.

[0028] Furthermore, the tensile strength of the industrial paper wiper 1 in the dry longitudinal direction according to JIS P 8113 is preferably 31.4 N / 25 mm or more and 73.2 N / 25 mm or less, and more preferably 35.2 N / 25 mm or more and 68.0 N / 25 mm or less. The tensile strength of the industrial paper wiper 1 in the dry transverse direction according to JIS P 8113 is preferably 7.8 N / 25 mm or more and 26.2 N / 25 mm or less, and more preferably 9.8 N / 25 mm or more and 20.9 N / 25 mm or less. Having the tensile strengths in each direction in the dry state within the above numerical ranges ensures that the industrial paper wiper 1 is strong (durable). The tensile strengths in each direction in the dry state are all measured in accordance with JIS P 8113.

[0029] (Embossed) The embossing (embossing 20) applied to the paper industrial wiper 1 in this embodiment is not particularly limited as long as it is an embossing used in ordinary paper products, such as matched embossing or pin embossing, but pin embossing is preferred. When pin embossing is used, the height of the pin embossed portion of the industrial paper wiper 1, i.e., the height of the embossed portion 20 shown in FIG. 1 (emboss height H), is preferably 300 μm or more and 850 μm or less, and more preferably 420 μm or more and 700 μm or less. When the emboss height H is within the above numerical range, the industrial paper wiper 1 can have excellent water absorption (amount of water absorbed per unit weight, water absorption rate). The emboss height H is determined by measuring the height of the embossment 20 of the industrial paper wiper 1 with a 3D microscope VR-3000 (manufactured by Keyence Corporation) and averaging the measurements at 30 points.

[0030] Furthermore, in the plan view of the embossed portion of the industrial paper wiper 1 shown in Figure 2, viewed from the surface (i.e., the concave side of the embossments 20), the pitch between the nearest embossments 20 (embossment pitch D) is preferably 1.0 mm or more and 3.8 mm or less, and more preferably 1.5 mm or more and 3.2 mm or less. By having the emboss pitch D within the above numerical range, the industrial paper wiper 1 can be made to have excellent water absorption (amount of water absorbed per unit weight, water absorption speed). The emboss pitch D is calculated by measuring the distance between the embossments 20 of the industrial paper wiper 1 using a microscope VHX-6000 (manufactured by Keyence Corporation) and averaging the distances measured at 30 points.

[0031] Furthermore, the area ratio of the embossments 20 (pin embossments) on the industrial paper wiper 1 is preferably 0.42% or more and 1.40% or less, and more preferably 0.57% or more and 1.05% or less. When the area ratio is within the above numerical range, the industrial paper wiper 1 can have excellent water absorption (amount of water absorbed per unit weight, water absorption speed). The area ratio is determined by measuring the area of the topmost part (the part close to the surface) of the holes (embossments 20) on the surface of the industrial paper wiper 1 using a microscope VHX-6000 (manufactured by Keyence Corporation) and converting the average value of 30 measured points into a ratio per unit area (area ratio).

[0032] (base paper) The base paper 10 (before plying) used to manufacture the paper industrial wiper 1 can be made from either bleached pulp (white) or unbleached pulp (brown), but it is preferable to use bleached pulp (white) from the standpoint of water absorption speed. The raw material composition can be softwood kraft pulp, hardwood kraft pulp, or pulp recycled from milk cartons (MSF), but from the viewpoint of water absorbency, it is preferable to use 100% virgin pulp. From the viewpoint of the strength of the final paper industrial wiper 1, it is more preferable to use 80% or more softwood kraft pulp, and even more preferable to use 100%.

[0033] The basis weight of the base paper 10 manufactured using the above-mentioned raw material blend was 18.7 g / m 2 More than 26.7g / m 2 less than or equal to 20.0 g / m 2 More than 25.3g / m 2 By setting the basis weight of the base paper 10 within the above range, the industrial paper wiper 1 can be made to have both water absorbency (amount of water absorbed per unit weight, water absorption speed) and durability.

[0034] Furthermore, it is preferable that the thickness of the base paper 10 is 0.78 mm / 10 ply or more and 1.25 mm / 10 ply or less, and 0.89 mm / 10 ply or more and 1.13 mm / 10 ply or less. By making the thickness of the base paper 10 within the above numerical range, it is possible to obtain an industrial paper wiper 1 that combines water absorbency (amount of water absorbed per unit weight, water absorption speed) and durability.

[0035] Furthermore, the crepe height of the base paper 10 is preferably 22.0 μm or more and 41.5 μm or less, and 27.2 μm or more and 36.7 μm or less. The number of crepes of the base paper 10 is preferably 15 / 6 mm or more and 32 / 6 mm or less, and 20 / 6 mm or more and 29 / 6 mm or less. By setting the crepe height and number of crepes of the base paper 10 within the above numerical ranges, the thickness and stiffness of the base paper 10 become appropriate, and embossing of appropriate size and depth can be applied after ply-up, resulting in an industrial paper wiper 1 that combines water absorbency (amount of water absorbed per unit weight, water absorption speed), good feel, and durability. Crepes are wavy wrinkles formed by mechanically compressing the base paper 10 in the longitudinal direction by a paper machine during the manufacturing process of the base paper 10, and can further improve the bulk, softness, water absorbency, surface smoothness, aesthetic appearance (crepe shape), elongation, etc. of the base paper 10. The crepe height and number of crepes can be measured using the measurement method described in JP 2019-051028 A, for example.

[0036] Furthermore, the D value of the base paper 10 measured by a tissue softness measuring device (TSA) is preferably 1.2 mm / N or more and 2.8 mm / N or less, and more preferably 1.5 mm / N or more and 2.5 mm / N or less. By setting the D value of the base paper 10 within the above range, the thickness and stiffness of the base paper 10 become appropriate, allowing embossing of appropriate size and depth to be performed after ply-up, and making it possible to obtain an industrial paper wiper 1 that combines water absorbency (amount of water absorbed per unit weight, water absorption speed), wiping performance, and durability.

[0037] The D value in this case is a numerical value indicating the rigidity (cushioning property) of the base paper 10, which is expressed by the amount of deformation displacement in the vertical direction of the sample when a tissue softness measuring device TSA (manufactured by emtec; Tissue Softness Analyzer) is used to press a sample of the base paper 10 placed on a sample stage from above with a pressing pressure of 100 mN and 600 mN, respectively, without rotating a bladed rotor. The method for measuring the D value using the tissue softness measuring device TSA and the measuring device used therein are described in detail, for example, in JP 2013-236904 A. Please refer to the above patent documents for various measuring methods using the tissue softness measuring device TSA.

[0038] When adjusting the strength at the base paper 10 stage, methods such as beating in a double disc refiner (DDR) or adding wet strength agents or dry strength agents can be selected as appropriate. However, if the beating in the DDR is strengthened, the paper will become tighter (reducing cushioning) and the embossing 20 will not be able to be easily achieved, so it is preferable to add wet strength agents or dry strength agents to increase the strength.

[0039] The wet strength agent is not particularly limited, but a polyamide polyamine epichlorohydrin-based agent is preferred. A dry strength agent may also be used, with a PAM-based dry strength agent being preferred. The wet strength agent may also contain an auxiliary agent, with an anionic polyacrylamide resin being preferred as the auxiliary agent for the wet strength agent. From the viewpoint of water absorption rate, the addition rate of the strength agent and auxiliary agent is preferably 1.0% or less based on the bone dry pulp weight. Adding a large amount of agent may result in poor water absorption rate.

[0040] As described above, according to this embodiment, it is possible to provide a paper industrial wiper 1 that combines water absorbency (amount of water absorbed per unit weight, water absorption speed), wiping performance, good feel, and durability. [Example]

[0041] The present invention will be explained 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.

[0042] Under the conditions shown in Tables 1 and 2, paper industrial wipers (products) were produced for each of Examples 1 to 16 and Comparative Examples 1 to 13, and the following evaluations were carried out. Note that each parameter other than the evaluations below was measured according to the standards or measurement methods described above.

[0043] (Durability when used to wipe away moisture) Sensory evaluation of durability during use was conducted on 50 people, with each person rating it on a scale of 1 to 5. The overall evaluation was based on the following criteria: "Excellent ◎": Particularly resistant to tearing and can be used repeatedly. Average score of 50 people was 4.0 or higher. "Good": Hard to tear and can be used without problems. Average score is between 3.0 and 4.0 points. "Fair △": The wiper may be partially torn, but this does not seriously impede use. Average score is between 2.0 and 3.0 points. "Poor x": The wiper is easily torn, hindering wiping work. Average score is less than 2.0 points.

[0044] (Wiping ability when used to wipe away moisture) Sensory evaluation of wiping performance was conducted by 50 people, who each rated the wipeability on a scale of 1 to 5. The overall evaluation was based on the following criteria: "Excellent ◎": The paper has just the right amount of elasticity, making it particularly easy to wipe off. Average score of 50 people was 4.0 points or higher. "Good": The paper is elastic and can be wiped off smoothly. Average score is between 2.0 and 4.0 points. "Failed": The paper is not elastic enough to wipe smoothly. Average score is less than 2.0 points.

[0045] (Feel when touching the wiper surface when dry) Sensory evaluation of the wiper feel was conducted by 50 people, who each rated the feel on a scale of 1 to 5. The overall evaluation was based on the following criteria: "Excellent ◎": Very smooth and feels particularly good to the touch. Average score of 50 people was 4.0 points or more. "Good": Smooth and feels good to the touch. Average score is 3.0 or more and less than 4.0 points. "Fair △": Moderately smooth and feels good to the touch. Average score is between 2.0 and 3.0 points. "Fail ×": The surface is not smooth and feels bad to the touch. Average score is less than 2.0 points.

[0046] (TWA) The water absorption per unit weight (TWA) of the evaluation of water absorbency was evaluated using the following method and the TWA values were measured according to the following criteria. 3.2g / g or more: Excellent ◎ → Able to absorb particularly large amounts of water. 2.8g / g or more, less than 3.2g / g: Good ○ → Can absorb a lot of moisture. 2.4g / g or more, less than 2.8g / g: Acceptable △ → Able to absorb an appropriate amount of moisture. Less than 2.4g / g: Unacceptable × → The amount of water absorption is low, which hinders use as a wiper.

[0047] The total water absorbency (TWA) per unit weight was measured by first cutting the obtained paper industrial wiper into a 76 x 76 mm square test piece and measuring the dry mass (W1). After immersing the test piece in distilled water for 2 minutes, the test piece was hung in a stretched state (RH 100%) with one corner of the test piece positioned at the top, supported by this top and the two adjacent corners, and left for 30 minutes, after which the mass (W2) was measured. The value of (W2 - W1) was then calculated, and this value was applied to 1 m of the sample. 2 Water retention capacity per unit (g / m 2 ) and then convert it to the product basis weight (g / m 2 ) to obtain the water absorption per unit weight (TWA) per gram of raw pulp.

[0048] (Water absorption rate) The water absorption rate, which was evaluated based on the number of seconds it took for a drop of 0.1 ml of water to be absorbed (light reflection to disappear) (so-called drop water absorbency), was measured according to the following criteria. Less than 1.5 seconds: Excellent ◎ → Absorbs moisture particularly quickly. 1.5 seconds or more, less than 2.0 seconds: Good ○ → Absorbs moisture quickly. 2.0 seconds or more, less than 3.0 seconds: Acceptable △ → Able to absorb moisture in an appropriate amount of time. 3.0 seconds or more: Not acceptable × → The moisture absorption rate is slow, which hinders use as a wiper.

[0049] Table 1 shows the conditions and evaluation results of each example, and Table 2 shows the conditions and evaluation results of each comparative example.

[0050] [Table 1]

[0051] [Table 2]

[0052] From the above, it was at least confirmed that this example can provide an industrial paper wiper that combines water absorbency (amount of water absorbed per unit weight, water absorption speed), wiping properties, a good feel, and durability. [Explanation of symbols]

[0053] 1 Paper Industrial Wipers 10 Base paper 20 Embossing D Embossing pitch H Embossing height

Claims

1. Basis weight: 18.7 g / m ２ 26.7g / m or more ２ The following is an industrial paper wiper, which is made by plying together base paper having a paper thickness of 0.78 mm / 10 plies or more and 1.25 mm / 10 plies or less, a crepe height of 27.2 μm or more and 36.7 μm or less, a number of crepes of 15 / 6 mm or more and 32 / 6 mm or less, and a D value of 1.5 mm / N or more and 2.5 mm / N or less, measured by a tissue softness measuring device TSA, into 2 plies or more and 6 plies or less, and embossing the base paper to form an integrated wiper: The embossing is pin embossing, The height of the pin embossed portion is 300 μm or more and 850 μm or less, A paper industrial wiper characterized in that the wiper has a tensile strength in the longitudinal direction when dry of 31.4 N / 25 mm or more and 73.2 N / 25 mm or less, and a tensile strength in the transverse direction when dry of 7.8 N / 25 mm or more and 26.2 N / 25 mm or less, according to JIS P 8113.

2. 2. The paper industry wiper according to claim 1, characterized in that the number of plies is 3 or 4.

3. 2. The paper industry wiper according to claim 1, wherein the area ratio of the pin embossings on the wiper is 0.42% or more and 1.40% or less.

4. 4. The paper industrial wiper according to claim 1, wherein the pitch between the nearest embossments is 1.0 mm or more and 3.8 mm or less.

5. The basis weight of the wiper is 56.1 g / m ２ More than 106.8g / m ２ 5. The paper industrial wiper according to any one of claims 1 to 4, characterized in that:

6. 6. The paper industrial wiper according to claim 1, wherein the paper thickness of the wiper is 0.40 mm or more per number of plies of the product and 0.81 mm or less per number of plies of the product.

7. 7. The paper industrial wiper according to claim 1, wherein the wiper is folded in four.

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