FIBER WEB PRODUCT AND MANUFACTURING METHOD OF THE SAME

Abstract

A fiber web containing hardwood pulp is impregnated with a chemical solution that contains a moisturizing component such as glycerin, moisture, an oily component such as hydrocarbons, and a vegetable powder such as corn starch. The vegetable powder enters between pulp fibers of the fiber web in which hydrogen bonds are relaxed by the moisturizing component and the oily component, thereby spontaneously raising some of the pulp fibers in a surface of the fiber web. Accordingly, a fiber web product that is excellent in texture characteristics such as a smooth raised feeling, softness, and moistness, generates less dust such as powder or pulp fibers, and has sufficient strength, and a manufacturing method of the same are provided.

Claims

1. A fiber web product comprising a fiber web that contains hardwood pulp and is impregnated with a chemical solution, the chemical solution containing a moisturizing component, moisture, an oily component, and a vegetable powder containing starch.

2. The fiber web product according to claim 1, wherein the fiber web is dry crepe paper.

3. The fiber web product according to claim 1, wherein the fiber web contains 50 wt % or more of hardwood pulp.

4. The fiber web product according to claim 1, wherein the moisturizing component contains glycerin.

5. The fiber web product according to claim 1, wherein the oily component contains hydrocarbons.

6. The fiber web product according to claim 1, wherein the starch is corn starch.

7. The fiber web product according to claim 1, wherein an average particle diameter of the vegetable powder is 2 to 50 m.

8. The fiber web product according to claim 1, wherein a blending ratio of the moisturizing component, the moisture, the oily component, and the vegetable powder in the chemical solution at 23 C. and a relative humidity of 50% is 1:0.05 to 1.0:0.01 to 1.0:0.01 to 1.0.

9. The fiber web product according to claim 1, wherein the vegetable powder intervenes between pulp fibers of the fiber web in which hydrogen bonds are relaxed by the moisturizing component and the oily component, to raise the pulp fibers.

10. The fiber web product according to claim 9, wherein number of the pulp fibers raised to protrude and have a height of 0.1 mm or more from a surface of the fiber web is 400 or more per 160 mm.sup.2 of a surface area of the fiber web.

11. The fiber web product according to claim 9, wherein number of particles of dust that contains the vegetable powder or the pulp fibers, is generated from the fiber web, and falls off from the fiber web is 6000 or less per 1800 cm.sup.2 of the surface area of the fiber web.

12. A manufacturing method of a fiber web product, comprising: preparing a chemical solution containing a moisturizing component, moisture, an oily component, a vegetable powder containing starch, and a surfactant; and impregnating a fiber web containing hardwood pulp with the chemical solution by spraying or roll coating.

13. The manufacturing method of a fiber web product according to claim 12, wherein the chemical solution is prepared by blending the starch that is the vegetable powder to an emulsion containing the moisturizing component, the moisture, the oily component, and the surfactant while a temperature of the emulsion is maintained at 60 C. or less, and the fiber web is impregnated with the chemical solution at a temperature of C. or less.

14. The fiber web product according to claim 2, wherein the fiber web contains 50 wt % or more of hardwood pulp.

15. The fiber web product according to claim 2, wherein the moisturizing component contains glycerin.

16. The fiber web product according to claim 2, wherein the oily component contains hydrocarbons.

17. The fiber web product according to claim 2, wherein the starch is corn starch.

18. The fiber web product according to claim 2, wherein an average particle diameter of the vegetable powder is 2 to 50 m.

19. The fiber web product according to claim 2, wherein a blending ratio of the moisturizing component, the moisture, the oily component, and the vegetable powder in the chemical solution at 23 C. and a relative humidity of 50% is 1:0.05 to 1.0:0.01 to 1.0:0.01 to 1.0.

20. The fiber web product according to claim 2, wherein the vegetable powder intervenes between pulp fibers of the fiber web in which hydrogen bonds are relaxed by the moisturizing component and the oily component, to raise the pulp fibers.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0043] FIG. 1 is a diagram (a photograph) illustrating a state of raising of pulp fibers.

[0044] FIG. 2 is an explanatory diagram of a sample for measuring the number of raised fibers.

[0045] FIG. 3 is a sectional diagram schematically illustrating a state of a raising of a specimen.

[0046] FIG. 4 is an explanatory diagram of a dust particle measurement method.

[0047] FIG. 5 is an explanatory diagram of the dust particle measurement method.

DESCRIPTION OF EMBODIMENTS

[0048] Embodiments of the present invention will now be explained with reference to the drawings.

[0049] Table 1 represents blending of components and various evaluation results in examples in which an embodiment of the present invention is embodied, and Table 2 represents blending of components and various evaluation results in comparative examples.

TABLE-US-00001 TABLE 1 Examples 1 2 3 4 5 Base Pulp blending Hardwood 50 70 80 90 90 Paper ratio [%] Softwood 50 30 20 10 10 Basis weight [g/m.sup.2] 15 15 15 15 15 Chemical - Moisturizing Glycerin (98. 5 [%] or more) 60 60 60 60 60 solution component and Sorbitol (Solid content 70 [%]) 10 10 10 10 10 part by moisture Water 20 20 20 20 20 weight Oily Liquid paraffin (Pour point 12.5 [ C.]) 5 5 5 5 5 component Squalane (Pour point 38 [ C.]) Solid paraffin (Melting point 46 to 48 [ C.]) Powder Vege- Corn starch (Average particle diameter 14 [m]) 5 5 5 5 10 table Potato starch (Average particle diameter 40 [m]) Miner- Talc (Average particle diameter 5.1 [m]) al Kaolin (Average particle diameter 4.8 [m]) Surfactant Mixture of polyoxyethylene sorbitan fatty 1 1 1 1 1 acid ester and sorbitan fatty acid ester Chemical-solution impregnation ratio [%] 25 25 25 25 25 Evalua- Number of Fibers 476 526 681 847 1272 tion raised fibers results Dust Particles 1386 1402 1539 1650 1823 Touch Smooth raised feeling Softness Moistness Non-stickiness Strength (longi- N 2.28 2.11 2.02 1.82 1.88 tudinal) Examples 6 7 8 9 Base Pulp blending Hardwood 90 80 80 80 Paper ratio [%] Softwood 10 20 20 20 Basis weight [g/m.sup.2] 15 15 15 15 Chemical - Moisturizing Glycerin (98. 5 [%] or more) 60 60 60 60 solution component and Sorbitol (Solid content 70 [%]) 10 10 10 10 part by moisture Water 20 20 20 20 weight Oily Liquid paraffin (Pour point 12.5 [ C.]) 2 5 component Squalane (Pour point 38 [ C.]) 5 Solid paraffin (Melting point 46 to 48 [ C.]) 5 Powder Vege- Corn starch (Average particle diameter 14 [m]) 10 5 5 table Potato starch (Average particle diameter 40 [m]) 5 Miner- Talc (Average particle diameter 5.1 [m]) al Kaolin (Average particle diameter 4.8 [m]) Surfactant Mixture of polyoxyethylene sorbitan fatty 0.4 1 1 1 acid ester and sorbitan fatty acid ester Chemical-solution impregnation ratio [%] 25 25 25 25 Evalua- Number of Fibers 818 667 482 644 tion raised fibers results Dust Particles 3822 1705 1727 2278 Touch Smooth raised feeling Softness Moistness Non-stickiness Strength (longi- N 1.80 1.92 1.72 1.98 tudinal)

TABLE-US-00002 TABLE 2 Comparative examples 1 2 3 4 5 6 7 Base Pulp blending Hardwood 80 80 80 70 0 70 0 Paper ratio [%] Softwood 20 20 20 30 100 30 100 Basis weight [g/m.sup.2] 15 15 15 15 15 15 15 Chemical - Moisturizing Glycerin (98.5 [%] or more) 60 60 60 60 60 solution component and Sorbitol (Solid content 70 [%]) 10 10 10 10 10 part by moisture Water 20 20 20 20 20 weight Oily Liquid paraffin (Pour point 12.5 [ C.]) 5 5 5 5 component Squalane (Pour point 38 [ C.]) Solid paraffin (Melting point 46 to 48 [ C.]) Powder Vege- Corn starch (Average particle diameter 14 5 5 table [m]) Potato starch (Average particle diameter 40 [m]) Miner- Tale (Average particle diameter 5.1 [m]) 5 al Kaolin (Average particle diameter 4.8 5 [m]) Surfactant Mixture of polyoxyethylene sorbitan fatty 1 1 1 1 acid ester and sorbitan fatty acid ester Chemical-solution impregnation ratio [%] 25 25 25 25 25 Evalua- Number of Fibers 386 324 532 324 144 304 122 tion raised fibers results Dust Particles 21087 43749 7614 1764 1233 3594 1800 Touch Smooth raised feeling X X Softness X Moistness X X Non-stickiness Strength (Longi- N 1.36 1.49 1.88 1.94 4.45 2.24 5.23 tudinal)

[0050] In the first to ninth examples in Table 1, a pulp blending ratio, the type and amount of an oily component in a chemical solution, and the type of a vegetable powder were changed.

[0051] In the first and second comparative examples in Table 2, a mineral powder was blended to a chemical solution. In the third comparative example, neither an oily component nor a surfactant was blended. In the fourth comparative example, a powder was not blended. In the fifth comparative example, a fiber web contained only softwood pulp. In the sixth and seventh comparative examples, sheets of fiber web base paper were not impregnated with a chemical solution.

[0052] A papermaking method of a fiber web and a method for impregnating the fiber web with a chemical solution are as follows.

[0053] A pulp slurry of unbeaten NBKP (softwood kraft bleached pulp: weight-weighted average fiber length: 2.4 to 2.6 [mm], fiber coarseness: 0.148 [mg/m]) was beaten so that the down width of the Canadian Standard Freeness was 40 to 60 [ml]. In addition, a pulp slurry of LBKP (hardwood kraft bleached pulp: weight-weighted average fiber length: 0.60 to 0.72 [mm], fiber coarseness: 0.057 [mg/m]) was beaten so that the down width of the Canadian Standard Freeness was 30 to 40 [ml].

[0054] Subsequently, the pulps were mixed so as to achieve the pulp blending ratios described in Tables 1 and 2, and a wet strength agent was added in an amount of 0.2 [wt %] in terms of solid content per pulp. Thereafter, dry crepe paper was made by a usual method using a paper machine.

[0055] The obtained crepe paper had a basis weight of 15 [g/m.sup.2] and a crepe ratio of 24[%]. Two sheets of the crepe paper were stacked and wound in a roll shape.

[0056] Next, each of the chemical solutions obtained by blending the components represented in Table 1 and Table 2 was continuously sprayed on the two-ply base paper from both sides thereof in an amount of 25 [wt %] per crepe paper, and the base paper was again wound into a roll. Thereafter, the rolled crepe paper was allowed to stand at room temperature for 24 hours or more, whereby the entire fiber web was uniformly impregnated with the chemical solution.

[0057] Next, a large number of samples were prepared by cutting the two-ply base paper into a size of 200 [mm] in the vertical direction (a papermaking direction) and 225 [mm] in the horizontal direction (a papermaking width direction) so that the dryer surface of the crepe paper was the front.

[0058] Each sample was then allowed to stand in an environment at a temperature of 235[ C.] and a humidity of 505[%] for 24 hours or more, and was evaluated by performing the following sensory evaluation (texture test) and physical property test.

A. Sensory Evaluation (Texture Test)

[0059] Ten monitors touched each sample with their hands and evaluated the touch (a smooth raised feeling, softness, moistness, and non-stickiness) according to the following criteria.

[0060] That is, as for the smooth raised feeling, the softness, and the moistness, very excellent was given 3 points, excellent was given 2 points, slightly excellent was given 1 point, and not excellent was given 0 points. The scores given by the ten monitors were summed and ranked as follows. [0061] 26 to 30 points: [0062] 16 to 25 points: [0063] 6 to 15 points: [0064] 0 to 5 points: X

[0065] According to the above ranking, represents that a corresponding sample is the most excellent, and X represents that a corresponding sample is the least excellent.

[0066] The stickiness due to the oily component was evaluated according to the following criteria.

[0067] That is, strongly sticky feeling was given 3 points, sticky feeling was given 2 points, slightly sticky feeling was given 1 point, and no sticky feeling was given 0 points. The scores given by the ten monitors were summed and ranked as follows. [0068] 26 to 30 points: X [0069] 16 to 25 points: [0070] 6 to 15 points: [0071] 0 to 5 points:

[0072] According to the above ranking, X represents the stickiest state, and represents the least sticky state.

B. Physical Property Test

(1) Measurement of the Number of Raised Fibers (Degree of Raising)

[0073] A raised fiber defined herein is a single pulp fiber that protrudes from a fiber web surface and has one end in the longitudinal direction of the fiber in the fiber web and the other end rising from the fiber web surface. In this test, the number of fibers in raised fibers, in which the protruding height from the fiber web surface is 0.1 [mm] or more, is counted.

[0074] FIG. 1 is a diagram (a photograph) illustrating a state of raising of pulp fibers. When the number of raised fibers (raised-fiber number) denoted by arrows A in FIG. 1 is large and the raised fibers are soft, a thick and smooth texture is expressed. The number of raised fibers in which the protruding height from the fiber web surface is 0.1 [mm] or more is preferably 400 or more under a measurement condition described below, more preferably 500 or more, and further preferably 600 or more.

[0075] A specific method of measuring the number of raised fibers is as follows.

[0076] As illustrated in FIG. 2, a two-ply sample 10 is folded along a folding line 11 crossing a papermaking direction B at 45 degrees with a slide glass 21 interposed therebetween as illustrated in FIG. 3, and the folded sample 10 is sandwiched from both sides by other slide glasses 22 and 23. A specimen 24 is thus prepared.

[0077] The specimen 24 described above is set on a horizontally movable stage under a microscope, and a state of raising at an end of the specimen 24 is observed in a direction C perpendicular to the slide glasses 21 to 23.

[0078] The number of raised fibers 12 having a height of 0.1 [mm] or more in raised fibers protruding from the end of the specimen 24 is counted over a length of 2.5 [mm] of the sample 10 within a visual field of the microscope.

[0079] The series of measurements described above are performed 40 times while changing the measurement position on the sample 10, and the results are totaled to obtain the number of the raised fibers 12 per 100 [mm] in length of the sample 10.

[0080] As the slide glasses 21 to 23, those having a thickness of 1.3 [mm], a length of 76 [mm], and a width of 26 [mm] were used, and the observation magnification by the microscope was set to 40 times.

[0081] The measurement range of the sample 10 in this measurement is 100 [mm] in the lengthwise direction (L) and 1.6 [mm] in the widthwise direction (W), which is obtained by adding the thickness (0.15 [mm]2) of the sample 10 to the thickness 1.3 [mm] of the slide glass 21. Therefore, the measurement area (S) is 160 [mm.sup.2] from S=LW.

[0082] Although FIG. 3 illustrates a case of the two-ply sample 10, the sample may be one-ply or three or more ply. In addition, the width direction (W) of the measurement range is changed depending on the thickness of the sample 10, and in association with this change, the measurement area (S) is also changed. However, the number of raised fibers is obtained by converting the measurement area (S) to 160 [mm.sup.2].

(2) Dust Particle Measurement

[0083] Powder and pulp fibers falling off when a mechanical impact is applied to a fiber web are defined as dust, and the number of dust particles is measured by a particle number measuring device.

[0084] The number of the dust particles is preferably 6000 or less, more preferably 5000 or less, and further preferably 4000 or less per 1800 [cm.sup.2] of a surface area of the fiber web.

[0085] As a specific measurement method, a series of measurements described below was performed ten times to obtain a mean value of the number of dust particles.

[0086] First, as illustrated in FIG. 4, the sample 10 is placed in a plastic bag with zipper 30, and air is enclosed therein. The plastic bag 30 is set on a horizontal rotating shaft 40 of a rotating device and rotated at a rotation speed of 25 [times/min] for 10 minutes. As a result, an impact is applied to the sample 10 falling in any direction (mainly in the radial direction of a rotation path) within the plastic bag 30, and dust falls off from the sample 10.

[0087] Next, as illustrated in FIG. 5, the number of dust particles present in the plastic bag 30 is measured by a particle number measuring device 50. A value of a blank test (the number of dust particles in the plastic bag 30 in which the sample 10 is not enclosed) is then subtracted from the measured value, and the number of dust particles generated and falling off from the sample 10 is counted.

[0088] The measurement condition is as follows. [0089] Rotating device: Scroller SCR-120 type (manufactured by Iuchi Seieido Co., Ltd.) [0090] Plastic bag: 240 [mm] in width340 [mm] in length0.04 [mm] in thickness, capacity 4.0 [L] [0091] Measured particle diameter of dust: 5 [m] or more [0092] Particle number measuring device: Particle monitor GT-32 (manufactured by SIBATA SCIENTIFIC TECHNOLOGY LTD.) [0093] Measuring time: 60 [seconds] [0094] Suction amount of air by particle number measuring device: 2.83 [L/min] [0095] Size of sample in this measurement: 200 [mm] in length225 [mm] in width, two-ply [0096] Surface area: 200 [mm]225 [mm]4 (both surfaces of two-ply paper)=1800 [cm.sup.2]

[0097] The surface area varies depending on the size of the sample, and the number of dust particles is calculated in terms of the surface area of 1800 [cm.sup.2].

(3) Strength Test

[0098] According to JIS S3104 (tissue paper), dry tensile strength in the longitudinal direction (the papermaking direction) of a fiber web was measured 10 times, and the mean value thereof was determined.

C. Evaluations

[0099] From the results of the tests described above, the following evaluations can be made.

(1) EXAMPLES

[0100] In the first to fourth examples in Table 1, only the pulp blending ratio was changed, and the components of the chemical solution and the chemical-solution impregnation ratio were the same.

[0101] According to the first to fourth examples, as a blending ratio of hardwood pulp gradually increases, softness, the number of raised fibers, and the number of dust particles also increase. This is considered to be because hardwood pulp has a shorter fiber length and a thinner fiber than softwood pulp, and therefore hydrogen bond points and hydrogen bond areas between pulp fibers are also narrow, and the sheet structure is easily loosened in the presence of the chemical solution. In addition, when the blending ratio of hardwood pulp is high, the absolute number of the pulp fibers is also large, and therefore the number of raised fibers is also increased.

[0102] The fifth example is an example in which the blending amount of the powder was increased from that in the fourth example. As compared to the fourth example, the number of the raised fibers was increased. It is considered that this increase is due to increase of the amount of the powder.

[0103] The sixth example is an example in which the amount of the oily component was reduced from that in the fifth example. The number of dust particles was increased from that in the fifth example. This is considered to be because an effect of adhering dust by the oily component was lowered.

[0104] In the seventh example, the type of the oily component in the third example was changed, and substantially equivalent evaluation results to those in the third example were obtained.

[0105] In the eighth example, a solid oily component was blended. Stickiness was slightly observed as compared to the third and seventh examples, and softness was also lowered.

[0106] In the ninth example, the type of the powder was changed from that in the third example, and softness was slightly lowered as compared to the third and seventh examples.

(2) COMPARATIVE EXAMPLES

[0107] In the first and second comparative examples in Table 2, powder was changed from a vegetable powder to a mineral powder such as talc or kaolin. The number of dust particles was incomparably larger than those in the first to ninth examples.

[0108] This is considered to be because particles of talc or kaolin are plate-like crystals and can easily peel off, and easily fall off and scatter from a fiber web to form dust, and because the average particle diameter of the powder is small, the number of powder particles per weight is large, and the effect of preventing the powder from falling off by a chemical agent is reduced.

[0109] In addition, in the first and second comparative examples, evaluation of a smooth raised feeling is also low. This is considered to be because the powder does not contribute to a smooth raised feeling accompanied by a feeling of thickness, although the smoothness is high due to a small average particle diameter of the powder.

[0110] In the third comparative example, the oily component was removed from the third example. The number of dust particles was considerably larger than that in the third example. From this result, it is effective to contain the oily component in a chemical agent for reducing dust.

[0111] The fourth comparative example is a sample in which only the powder was not blended in the second example. In the fourth comparative example, since the powder was removed, a sticky feeling due to the oily component was felt, and the number of raised fibers was decreased and evaluation of the raised feeling was also lowered.

[0112] In the fifth comparative example, pulp fibers contained only softwood pulp and did not contain hardwood pulp, and the number of raised fibers was small. The number of dust particles was the smallest among the comparative examples.

[0113] Since softwood pulp has thick and long fibers, hydrogen bonds between fibers are strong, and separation and raising of the pulp hardly occur in spite of the presence of the chemical solution. Further, since softwood pulp has a smaller number of fibers per area than hardwood pulp, the number of raised fibers is also smaller. Further, since the average particle diameter of the powder is small as compared to the size of pulp fibers, the touch of the powder is low and stickiness due to the oily component is felt.

[0114] In the sixth and seventh comparative examples, sheets of base paper were not impregnated with the chemical solution.

[0115] Although the sixth comparative example and the second example have the same pulp blending ratio, the number of raised fibers is larger, and generation of dust is reduced in the second example in which the powder is contained in the chemical solution. In other words, as in examples including the second example, by impregnating the fiber web with the chemical solution containing the moisturizing component, the moisture, the oily component, and the vegetable powder in a predetermined blending ratio, thick raised fibers are effectively generated, and falling off of the pulp fibers and the powder is reduced.

(3) SUMMARY

[0116] Pulp fibers in each example are raised by relaxation of hydrogen bonds between the pulp fibers due to a moisturizing component and an oily component and by intervention of powder (starch) between the pulp fibers. Therefore, a spontaneously generated raising state is obtained, unlike raising forcibly formed by a mechanical force as in the conventional technique.

[0117] When powder particles are too small as compared to the pulp fibers, an action of separating the pulp fibers from each other to promote raising is small. When the powder particles are too large, the powder is separated from the pulp fibers and falls off as dust. Therefore, by setting the average particle diameter of the powder to, for example, 2 to 50 [m], and preferably 5 to 30 [m], it is possible to generate appropriate raising, and to reduce generation and falling off of dust in cooperation with adhesiveness due to the oily component.

[0118] Further, since the raised pulp fibers are plasticized by the moisturizing component and smoothed by the oily component, the fibers give extremely soft touch when coming into contact with the skin.

[0119] Although each example contains an oily component, a sticky feeling was not felt so strongly.

[0120] The oily component is easily adsorbed to pulp fibers having higher lipophilicity than starch. Therefore, when the fiber web is brought into contact with the skin, an oily feeling of the pulp fibers and a non-oily feeling of the starch are simultaneously given, whereby smoothness without stickiness is expressed.

[0121] On the other hand, in a case where the thickness of the fibers is considerably larger than the particle diameter of the starch as in the softwood pulp of the fifth comparative example, for example, the starch is less likely to be touched and the oily feeling of the pulp fibers is strongly felt, when the fiber web surface is touched. The sticky feeling is thus considered to be increased.

[0122] In each example, there was a concern about decrease in paper strength due to intervention of the starch between the pulp fibers. However, decrease in strength was not particularly observed. This is considered to be because the pulp fibers are hydrogen-bonded to each other via the starch.

[0123] While the hydrogen bonds between the pulp fibers are nonflexible bonds, the bonds between the pulp fibers via the starch are flexible bonds with mobility because the starch itself is plasticized in the bonds by the moisturizing component and the moisture. As a result, the soft touch of the fiber web is maintained and decrease in strength is reduced.

[0124] The technical scope of the present invention is not limited to the respective examples and the components or numerical ranges can be arbitrarily changed without departing from the scope of the present invention.

INDUSTRIAL APPLICABILITY

[0125] The fiber web product according to the present invention has a smooth and thick raised feeling, is soft, has a moist texture, generates little dust, hardly causes the dust to fall off, and has a sufficient strength.

[0126] Accordingly, the fiber web product is significantly useful as a fiber web product used for hygienic and household uses such as tissue paper, toilet paper, and towel paper.

REFERENCE SIGNS LIST

[0127] 10: sample [0128] 11: folding line [0129] 12: raised fiber [0130] 21 to 23: slide glass [0131] 24: specimen [0132] 30: plastic bag [0133] 40: rotating shaft [0134] 50: particle number measuring device