JP2003070707A - Cleaning sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive cleaning sheet by forming a hardly collapsible uneven surface in a variety of unevenness density by one manufacturing process. SOLUTION: This is a hydroentangled nonwoven fabric cleaning sheet in which high density recess parts and low density projecting parts are alternately place in the web forming direction. The width of a recess part is 1-10 mm and a projecting part 2-30 mm. The density difference between recess parts and projecting parts is not lower than 20%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning sheet in which the surface of the sheet is uneven, and more particularly to a disposable type cleaning sheet used for business or household use.

[0002]

2. Description of the Related Art As a cleaning sheet, a simple sheet shape such as a wet or dry rag using a cloth or a non-woven cloth, a chemical rag, or a bundle of thread-like rags such as a mop It is used in homes, offices, stores, etc., depending on the purpose.

Recently, for example, Japanese Patent No. 30960 has been published.
As disclosed in Japanese Patent Publication No. 94, a heat-shrinkable net is arranged between webs, and the cleaning sheet is provided with unevenness due to the difference in heat shrinkage ratio between the web-constituting fibers and the net. Sheets provided with are commercially available. Both sheets have the purpose of improving the dust trapping property and the wiping property by providing uneven portions.

In order for the cleaning sheet to capture large and small dust, it is necessary to maintain the fiber density at an appropriate low level and capture dust in this fiber space, but the low fiber density lowers the sheet strength. It can be a cause. Therefore, the method of producing the strength by the entanglement while keeping the fiber density low by the hydroentanglement method is effective. In Japanese Patent No. 3096094, since the heat-shrinkable net is used as the reinforcing material, it is possible to maintain the fiber density low. However, this method has a disadvantage that it costs more than a cleaning sheet having only a web. Also, since the whole is a non-woven sheet of uniform density, it can only capture dust of a certain size or less, and furthermore, since this unevenness is formed by distorting the sheet itself, it is pressed against the floor surface. There is a problem that when crushed, it is easily crushed, and the crushed unevenness is close to a flat surface and the effect is halved.

[0005] In forming the unevenness by embossing, since the unevenness is imparted by the embossing roll after forming the web, there is a problem that the processing cost increases. Also, in order to make the embossing process effective, the embossed portion is often heat-sealed, but as a result, the fiber density of the embossed portion becomes extremely high, and the dust trapping power in this portion is also significantly reduced. There are drawbacks.

[0006]

As described above, in order for the cleaning sheet to capture dust, it is ideal to keep the fiber density low and form irregularities, but in the conventional method, the irregularities are crushed. There is a problem that it is easy and processing cost and manufacturing cost increase.

Therefore, an object of the present invention is to form irregularities having different densities in order to capture dusts of various sizes and to make the surface of the sheet irregular so that the sheet is not easily crushed, and further, in a single step. It is to provide an inexpensive cleaning sheet by manufacturing.

[0008]

SUMMARY OF THE INVENTION In order to solve these problems, the inventors of the present invention arrange a large portion and a small portion of energy from a nozzle used during web entanglement by a water entanglement method alternately. Alternatively, by providing a non-entangled portion, a high density portion and a low density portion can be easily formed at the same time when the web is formed, and the low density portion forms a convex portion and the high density portion forms a concave portion. However, it has been found that the low density portion has a weak entanglement, so that a space suitable for capturing dust is developed, and the high-density concave portion serves as a space for capturing larger dust. At the same time, they found that since the unevenness was formed in the surface of the sheet itself, the unevenness did not disappear even when pressed against the floor surface, and the capture effect did not decrease.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The cleaning sheet of the present invention is a cleaning sheet having a web formed by the hydroentangling method, wherein the web formed by the hydroentangling method has a high density portion and a low density in the web forming direction. The cleaning sheet is characterized in that unevenness is imparted to the web by alternately arranging the portions of the above, and the width of the high-density concave portions arranged in parallel to the web forming direction is 1 to 10 mm. The width of the low-density convex portions is 2 to 30 mm, and the density of the high-density concave portions is 0.1.
It is g / cm ³ or less, and the density of the low-density convex portion is 20% or more lower than that of the high-density concave portion. An example of the form of the cleaning sheet of the present invention is shown in FIG.

Usually, when a web is made into a nonwoven fabric by a hydroentangling method, nozzles that are uniformly perforated in the width direction of the web are arranged in several rows in the flow direction of the web to form a hydroentangled web. However, the surface of the web is almost flat over the entire surface.

However, in the cleaning sheet 1 of the present invention, the concave portions 2 and the convex portions 3 are alternately arranged. In the concave portion 2, the fiber density is increased by strengthening the fiber entanglement due to the hydroentanglement to form the concave portion. In the convex portion 3, the entanglement of fibers is loosened by weakening the water flow, and the fiber density is lowered to form the convex portion. The density difference between the convex portion and the concave portion is given by the difference in the energy of hydroentanglement. For example, in the process of producing a nonwoven fabric sheet by hydroentanglement as shown in FIG. An injection nozzle 5 having a portion with a nozzle hole and a portion without a nozzle hole as shown in FIG. 2C is arranged at the end of 4 and is arranged so that a convex portion and a concave portion can be formed. That is, as shown in FIG. 2B, the pitch of the holes of the ordinary water-entanglement nozzle is 6 for the hole diameter and 7 for the hole pitch.
Are arranged at equal pitches, but the last injection nozzle 5
As shown in FIG. 2C, the holes 8 and the holes 9 are regularly arranged. For this reason, the hole 8 of the rearmost injection nozzle 5 has a strong fiber entanglement and forms a concave portion, and the non-hole portion 9 has a weak fiber entanglement and forms a convex portion. When the density of the concave portions and the convex portions is measured, the density of the high-density concave portions is 0.1 g / cm ³ or less, and the density of the low-density convex portions is 20 g / cm ³ with respect to the high-density concave portions.
It is desirable that the density be at least%.

If it deviates from these ranges, it will be difficult to sufficiently exert the function of the present invention. That is, for flooring, large dust is human hair, soil, bread crumbs, etc., and small dust is wheat flour, baby powder, etc. However, if the density of the recesses is larger than 0.1 g / cm ³ , this portion It becomes difficult to capture dust between fibers in
The capture rate of small garbage is reduced. Further, when the difference in density between the low-density convex portion and the high-density concave portion is less than 20%, the depression of the concave portion is not large enough to capture dust, so that the capture rate of large dust decreases, As a whole, the garbage capture rate will also be significantly reduced.

The widths of the convex portions 3 and the concave portions 2 can be freely set according to the basis weight of the sheet and the content of the target dust, but as a household cleaning sheet, a regular arrangement or an irregular shape is used. The width of the convex portion 3 is 2 to 30
mm, and the width of the recess 2 is preferably set between 1 and 10 mm. Furthermore, the width of the convex portion 3 is 4 to 15 mm, and the concave portion 2
The width of 3 to 8 mm is more preferable from the viewpoint of dust capture rate. When the width of the convex portion 3 is less than 2 mm, the concave portion 2
It is difficult to set the density difference of the convex portions 3 to 20% or more, and conversely, if it is larger than 30 mm, the web strength is remarkably reduced, and the production by the hydroentangling method becomes difficult. If the width of the concave portion 2 is less than 1 mm, it becomes difficult to set the density difference between the concave portion and the convex portion to 20% or more, as in the case of the convex portion.
If it is larger than mm, the captured dust tends to come off the sheet, which is not desirable.

As described above, the unevenness is imparted by the last injection nozzle 5, but the injection nozzle 5 as a means for making the unevenness has holes at equal pitches as shown in FIG. 2D. It is possible by freely arranging the pitch of the holes and the diameter of the holes, such as a method of arranging the and changing the diameter of the holes. In the present invention, the position of the injection nozzle 5 for imparting the irregularities may be the front row or the middle as long as the irregularities can be imparted even if it is not at the end arranged in a plurality of rows, and it can be selected according to the required characteristics of the cleaning sheet. Good, but in general, placement at the end is most effective.

The selection of the grammage varies depending on the required characteristics of the cleaning sheet to be used, but a range of 40 to 70 g / m ² is desirable considering the type of fiber and the energy of hydroentanglement, but the cost of the cleaning sheet is low. 45-55 g / from the surface
The range of m ² is the most desirable.

The fibers used in the present invention are not particularly limited, and may be any commonly used fibers such as recycled fibers such as polyester fibers, acrylic fibers, rayon fibers, semi-synthetic fibers such as acetate, polyolefin fibers and the like. You can choose which one. Further, the shape of the hollow fiber, the crimped fiber, etc. is not limited. Further, it is possible to use not only one kind but also two or more kinds of fibers in combination.

Further, it is preferable to use the heat-fusible composite fiber because the strength of the cleaning sheet can be prevented from lowering. The amount used is not particularly limited, but it is desirable to use 20% by weight or less in order to make full use of the hydroentangling method.

The thickness of the fiber used is not particularly limited, but in order to make the density difference between the high density concave part and the low density convex part 20% or more, a fiber of 4.4 decitex or less is used. It is preferable to use 70% or more. If more than 30% of fibers larger than 4.4 decitex is used, the overall density becomes low and the irregularities become unclear, so it becomes difficult to make the density difference 20% or more.

The cleaning sheet of the present invention has a mineral oil-based oil agent, liquid paraffin, antibacterial agent,
1 selected from the group of antifungal agents, dusting agents, and silicone
It may be one in which an appropriate amount of one or more kinds of functionalizing agents is applied.

[0020]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The density and the wiping performance of the obtained cleaning sheet were measured by the following methods.

[Density] Density was calculated by the following formula from thickness and basis weight. The thickness was measured after standing for 10 seconds under a load of 2.2 g / cm ² . Density = basis weight / (thickness x 1000)

[Wipeability test 1 (JIS powder and crushed pulp wipeability test)] Simulated floor (white wood, 30 cm x
(60 cm) near the short side edge, spray test dust in a circle with a diameter of 15 cm, then attach a cleaning sheet to a flooring cleaning tool made by Kao Corporation (wiping area 10 cm x 26 cm), make two reciprocations, and measure the wiper weight. Then, the dust deposition rate was calculated by the following formula. Dust rate (%) = (wiper weight before test−wiper weight after test) / powder weight × 100 As test dust, 4 and 7 types of test powder 1 according to JIS (Z 8901) are used. 1 g of each and 0.2 g of ground pulp were used alone.

[Wipeability Test 2 (Hair Wipeability Test)] 1 hair on a simulated floor (white wood, 30 cm × 60 cm)
Evenly distribute 0 pieces within a circle with a diameter of about 15 cm,
Flooring cleaning tool manufactured by Kao Corporation (wiping area: 10
(cm × 26 cm) When the cleaning sheet was attached and reciprocated 10 times, the number of hairs remaining on the wiper was counted, and the dust coverage was calculated by the following formula. Dust rate (%) = (number of hairs remaining on wiper / 10)
× 100

[Embodiment 1] Based on the case where a web using 100% by weight of polyester fiber having a fiber length of 51 mm and 3.3 decitex was opened at a nozzle diameter of 0.16 mm and a pitch of 1 mm, two holes were formed. A nonwoven fabric having a basis weight of 50 g / m ² was produced by hydroentangling with a spunlace method using a nozzle in which a set of hole closing holes was repeated, and then liquid paraffin was applied at 3 g / m ² to prepare a cleaning sheet.

[Example 2] 50% by weight of polyester fiber having a fiber length of 38 mm with 1.7 decitex and 51 mm with 4.4 decitex having a sheath portion of polyethylene and a core portion of polyester were 35 heat-fusible composite fibers. Wt%, 6.7
A web prepared by mixing 15% by weight of hollow crimped polyester fibers having a fiber length of 64 mm with a decitex was used, and the nozzle diameter was 0.1.
Based on the case where holes were opened at a pitch of 3 mm and a pitch of 1 mm, a non-woven fabric with a basis weight of 50 g / m ² was produced by hydroentangling with a spunlace method using a nozzle that repeated 3 holes and 4 holes in one set After that, liquid paraffin was applied at 3 g / m ² to prepare a cleaning sheet.

Comparative Example 1 Polyester fiber 100 having a basis weight of 50 g / m ² and 1.7 decitex and a fiber length of 51 mm
Weight% is divided into 2 layers, heat-shrinkable net (distance between lines 9m
m) stacked above and below, nozzle diameter 0.16 mm, pitch 1
After manufacturing a nonwoven fabric by hydroentangling with the spunlace method using a nozzle with a hole of mm, 3 g of liquid paraffin
/ M ^{2 was} applied to prepare a cleaning sheet.

[Comparative Example 2] 50% by weight of polyester fiber having a fiber length of 51 mm and 3.3 decitex, and a heat-fusible composite fiber having a polyethylene portion of polyethylene and a core portion of polyester and having a fiber length of 51 mm and 1.7 decitex. A web mixed with 50% by weight is dried with hot air to produce a 50 g / m ² non-woven fabric, embossed in a shape as shown in (b) of FIG. 3, liquid paraffin is applied at 3 g / m ² to form a cleaning sheet. Created.

The test results of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1.

[0029]

[Table 1]

[0030]

EFFECT OF THE INVENTION The cleaning sheet of the present invention has the required strength, and has both the function of catching dust and the function of holding dust. The ability to catch miscellaneous dust is greatly improved, and even if the amount of dust is large, it can sufficiently cope with it, and the wiping performance is extremely good. That is, by alternately forming high-density concave portions and low-density convex portions with low fiber entanglement in the nonwoven web, dust trapping and holding properties are improved compared to conventional products, and relatively small dust traps are captured. Will also be possible.

In order to capture dust, when it is pressed against the surface to be cleaned such as the floor with a tool or the like, the existing cleaning sheet having unevenness loses its effect when pressed, but the cleaning sheet has a high density. The trapping property is significantly improved by alternately forming the concave portions having a high density and the convex portions having a low density and weak fiber entanglement. At the same time, relatively small dust among the captured dust can be captured at the convex portion having a low density and weak fiber entanglement, and when a large amount of dust or relatively large dust can be captured at the concave portion having a high density.

[Brief description of drawings]

1A and 1B are schematic diagrams showing an embodiment of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a sectional view taken along line AA of FIG.

FIG. 2 is a schematic diagram showing a manufacturing process of the present invention, (a) is a manufacturing process diagram showing an array of nozzles, and (b), (c),
(D) is a schematic diagram showing a form of a nozzle used in the manufacturing process of (a).

FIG. 3 is a schematic cross-sectional view showing a form of a conventional cleaning sheet, (a) is a cross section of a cleaning sheet having a concavo-convex pattern formed by using a heat-shrinkable net, and (b) is a concavo-convex pattern formed by embossing. It is a cross section of the applied cleaning sheet.

[Explanation of symbols]

1 cleaning sheet 2 High density recesses 3 Convex part with low density and weak fiber entanglement 4 injection nozzles 5 injection nozzles 6 nozzle diameter 7 nozzle pitch 8 Holes in the injection nozzle 9 Non-perforated part of injection nozzle

Claims (4)

[Claims] 1. A cleaning sheet having a web formed by the hydroentanglement method, wherein the web formed by the hydroentanglement method has high density portions and low density portions alternately arranged in the web forming direction. The cleaning sheet is characterized in that the web is provided with irregularities, and the width of the high-density recesses arranged in parallel to the web forming direction is 1 to 1.
10 mm, the width of the low-density convex portions is 2 to 30 mm, the density of the high-density concave portions is 0.1 g / cm ³ or less, and the density of the low-density convex portions is 20% with respect to the high-density concave portions. A cleaning sheet having a low density. 2. The cleaning sheet according to claim 1, wherein the low-density portion is formed by partially not subjecting the hydroentanglement method. 3. The cleaning sheet according to claim 1, which is formed using a heat-fusible composite fiber. 4. The cleaning sheet according to claim 1, wherein 70% or more of the fibers used have a thickness of 4.4 decitex or less.