Composite nonwoven fabric wiper

Abstract

To provide a conjugate type nonwoven fabric wiper which has a small difference in water absorption performance on front and back sides while maintaining whole water absorption performance and texture and has excellent dirt wiping property in the conjugate type nonwoven fabric wiper in which pulp fiber webs are laminated and integrated on synthetic fibers.SOLUTION: A conjugate type nonwoven fabric wiper is made by laminating and integrating pulp fiber webs on synthetic fibers and having synthetic fiber surfaces and pulp fiber surfaces. Protrusions and recesses of embossments are machined into a pattern shape by mutually corresponding horizontal rhombic shaped unit embossments on front and rear sides of the conjugate type nonwoven fabric on both surfaces of the conjugate type nonwoven fabric. A depth of the unit embossment is 0.2 mm or more and 2.0 mm or less. A horizontal distance between the protrusions adjacent to each other is 2.0 mm or more and 7.5 mm or less. A water absorbing speed of the synthetic fiber surface of the conjugate type nonwoven fabric is 1.0 sec / 0.1 mL or less. A ratio of water absorbing speed of the synthetic fiber surface to that of the pulp fiber surface is less than 1.30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a composite nonwoven wiper using an embossed composite nonwoven fabric. [Background technology]

[0002] Wipers, which are made by folding or rolling up sheets of paper or non-woven fabric, are known as products for wiping up water-based or oil-based liquids and keeping the wiped area hygienic.

[0003] One problem with these types of wipers is that paper wipers are excellent at absorbing water and oil, but generally lack strength. Similarly, non-woven fabric wipers are strong, but their water and oil absorption is inferior.

[0004] To address these problems, a technology is known for manufacturing sheets that combine strength and liquid absorption by entangling a web of pulp fibers, which have high liquid absorption properties for both water-based and oil-based liquids, with a spunbond nonwoven fabric made of synthetic fibers with excellent strength, using water flow. Pulp fiber webs can be supplied using general wet papermaking methods, sheets produced by wet papermaking, or dry airlaid papermaking.

[0005] As prior art documents for such composite nonwoven fabrics, for example, Patent Document 1 describes a manufacturing apparatus 1 for manufacturing a composite nonwoven fabric formed by laminating a pulp fiber layer and a synthetic fiber layer, comprising: a pulp airlaid section 2 that defibrates raw pulp in a dry state, disperses it with an airflow, and supplies pulp fibers to a lamination position 24; a synthetic fiber layer supply section 3 that uses a pre-prepared synthetic fiber web as a synthetic fiber layer and supplies it to the lamination position 24; and a section positioned opposite the lamination position 24, which supplies the synthetic fiber layer and the A composite nonwoven fabric manufacturing apparatus 1 is disclosed, comprising: a lamination forming section 4 that applies negative pressure to a pulp fiber layer formed by pulp fibers placed on a synthetic fiber layer to form a preliminary laminate PWeb; a water flow entanglement section 5 downstream of the lamination forming section 4 that applies a water jet to the preliminary laminate to perform a water flow entanglement treatment to promote integration between the pulp fiber layer and the synthetic fiber layer; and a dewatering and drying section 6 downstream of the water flow entanglement section that performs dewatering and drying treatment to obtain a laminate. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6758116 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In composite nonwoven fabrics, which are made by entangling pulp fibers with water on a spunbond nonwoven fabric of synthetic fibers, there are two sides due to the characteristics of the manufacturing method: one side with pulp fibers (hereinafter referred to as the pulp fiber side) and one side without pulp fibers (hereinafter referred to as the synthetic fiber side).

[0008] Because the fibers exposed on the front and back of such composite nonwoven fabrics differ, there are differences in water absorption performance. Changing the pulp / spunbond ratio to solve this problem can affect water absorption performance and texture.

[0009] Therefore, there is a demand for composite nonwoven fabrics that maintain water absorption performance and texture while minimizing the difference in water absorption performance between the front and back sides, as wipers. In addition, wipers with high dirt-wiping performance are desirable.

[0010] This invention has been made in view of these circumstances, and aims to provide a composite nonwoven fabric wiper, which is formed by laminating and integrating a pulp fiber web onto synthetic fibers, that maintains overall water absorption performance and texture while having little difference in water absorption performance between the front and back sides, and also has excellent dirt-wiping ability. [Means for solving the problem]

[0011] The inventors conducted diligent research and developed a composite nonwoven fabric wiper having a synthetic fiber surface and a pulp fiber surface, in which a pulp fiber web is laminated and integrated onto synthetic fibers. By adjusting the basis weight of the composite nonwoven fabric within a predetermined numerical range, and processing both sides of the composite nonwoven fabric with a pattern of horizontal diamond-shaped unit embossing where the convex and concave portions correspond on the front and back of the composite nonwoven fabric, and by adjusting the depth of the unit embossing, the horizontal distance between adjacent convex portions, and the ratio of the water absorption rate of the synthetic fiber surface and the water absorption rate of the pulp fiber surface to the synthetic fiber surface within predetermined numerical ranges, it was possible to create a composite nonwoven fabric wiper that maintains overall water absorption performance and texture while minimizing the difference in water absorption performance between the front and back surfaces, and also exhibiting excellent dirt-wiping ability. Thus, the present invention was completed. In other words, the present invention provides the following.

[0012] (1) A first aspect of the present invention is a wiper made of a composite nonwoven fabric having a synthetic fiber surface and a pulp fiber surface, wherein a pulp fiber web is laminated and integrated on a synthetic fiber, and the basis weight of the composite nonwoven fabric is 50 g / m². 2 More than 140g / m 2The composite nonwoven fabric wiper is characterized in that, on both sides of the composite nonwoven fabric, corresponding horizontal diamond-shaped unit embossing is processed in a pattern, the raised and recessed parts of the embossing are on the front and back sides of the composite nonwoven fabric, the depth of the unit embossing is 0.2 mm or more and 2.0 mm or less, the horizontal distance between the center points of the top surfaces of adjacent raised parts in the unit embossing is 2.0 mm or more and 7.5 mm or less within the plane of the composite nonwoven fabric, the water absorption rate of the synthetic fiber surface of the composite nonwoven fabric is 1.0 seconds / 0.1 mL or less, and the ratio of the water absorption rates of the pulp fiber surface to the synthetic fiber surface (water absorption rate of the synthetic fiber surface / water absorption rate of the pulp fiber surface) is less than 1.30.

[0013] (2) A second aspect of the present invention is a composite nonwoven wiper as described in (1), characterized in that the water absorption capacity (TWA) per unit weight of the composite nonwoven is 2.80 g / g or more.

[0014] (3) A third aspect of the present invention is a composite nonwoven wiper as described in (1), characterized in that the thickness of the composite nonwoven fabric is 1.50 mm / ply or less.

[0015] (4) A fourth aspect of the present invention is a composite nonwoven wiper as described in (1), characterized in that the thickness of the composite nonwoven fabric is 0.40 mm / ply or more. [Effects of the Invention]

[0016] According to the present invention, in a composite nonwoven fabric wiper in which a pulp fiber web is laminated and integrated on synthetic fibers, it is possible to provide a composite nonwoven fabric wiper that maintains overall water absorption performance and texture while having little difference in water absorption performance between the front and back sides, and also having excellent dirt-wiping ability. [Brief explanation of the drawing]

[0017] [Figure 1] This is an enlarged view of the unit embossing of the composite nonwoven wiper according to this embodiment. [Figure 2]FIG. 1 is a view seen from the back side of the composite non-woven fabric. [Figure 3] FIG. 2 is a cross-sectional view of the composite non-woven fabric of the L1 portion in FIG. 2 seen with a microscope.

MODE FOR CARRYING OUT THE INVENTION

[0018] 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 exemplification for explaining the present invention, and is not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of its gist.

[0019] In the drawings, the same reference numerals are assigned to the same elements, and duplicate explanations are omitted. Also, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the illustrated ratios. In addition, the MD direction in the wiper (composite non-woven fabric) is the flow direction (Machine Direction) when the composite non-woven fabric is manufactured, and the CD direction is the direction (Cross Direction) perpendicular to the MD direction.

[0020] <COMPOSITE NON-WOVEN FABRIC WIPER> The composite non-woven fabric wiper according to the present embodiment is a wiper of a composite non-woven fabric having a synthetic fiber surface and a pulp fiber surface, in which a pulp fiber web is laminated and integrated on synthetic fibers. The ply number of the wiper is not particularly limited, but is preferably 1 ply. Since the wiper is a composite non-woven fabric, it is possible to obtain a composite non-woven fabric wiper having a small difference in water absorption performance between the front and back and excellent dirt wiping performance by performing embossing processing described later while maintaining the overall water absorption performance and texture. In addition, the pulp supply method in the production of the composite non-woven fabric is not limited to wet or card disintegration methods, etc., but the airlaid method in which a pulp sheet is pulverized with a hammer mill and loaded as fluff pulp on synthetic fibers is preferable. Details of the manufacturing method of the composite non-woven fabric (wiper) will be described later.

[0021] (Composite nonwoven fabric) The synthetic fibers used in the composite nonwoven fabric preferably include one or more synthetic fibers selected from nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, or polystyrene. Among these, the inclusion of polypropylene is more preferable. Furthermore, it is preferable that the synthetic fibers are first formed as a nonwoven fabric in order to laminate the pulp fiber web. In this case, the nonwoven fabric is preferably formed by the spunlace method or the spunbond method, with the spunbond method being more preferable.

[0022] Furthermore, the pulp fibers used in the pulp fiber web can be general pulp fibers (wood pulp) such as bleached softwood kraft pulp (NBKP) and bleached hardwood kraft pulp (LBKP). Among these, it is preferable to include bleached softwood kraft pulp (NBKP) and bleached hardwood kraft pulp (LBKP). In addition, the content ratio of NBKP to LBKP in the pulp fibers is preferably 50:50 or more and 100:0 or less, more preferably 70:30 or more and 100:0 or less, even more preferably 90:10 or more and 100:0 or less, and most preferably 100:0. Preferred NBKP fibers include those made from radiata pine, slush pine, southern pine, lodgepole pine, spruce, and Douglas fir. NUKP can be used instead of NBKP, and LUKP can be used instead of LBKP.

[0023] The basis weight of the composite nonwoven fabric is 50 g / m². 2 That is all. 70g / m 2 The above is preferable. Furthermore, the basis weight is 140 g / m². 2 The following applies: 90g / m 2 The following is preferable: By having a basis weight within the above numerical range, a composite nonwoven wiper can be made that maintains its texture while also having excellent dirt-wiping properties. The basis weight of composite nonwoven fabrics is measured in accordance with JIS P 8124.

[0024] Furthermore, the ratio of the basis weight of pulp fibers to the basis weight of the composite nonwoven fabric is preferably 75% to 85%. Within this range, it is possible to create a composite nonwoven wiper that maintains overall water absorption performance while minimizing the difference in water absorption performance between the front and back sides.

[0025] The thickness of the composite nonwoven fabric is preferably 0.40 mm / ply or more, and more preferably 0.50 mm / ply or more. Furthermore, the thickness of the composite nonwoven fabric is preferably 1.50 mm / ply or less, and more preferably 1.25 mm / ply or less. By keeping the thickness within the above numerical range, it is possible to create a composite nonwoven fabric wiper that maintains overall water absorption performance and texture while also having excellent dirt-wiping properties. The thickness mentioned above is for one ply, and measured at 37.85 gf / m² using a Peacock paper thickness gauge. 2 Measured at [location / location].

[0026] Furthermore, the total water absorption capacity (TWA) of the composite nonwoven fabric is preferably 2.80 g / g or more, and more preferably 3.50 g / g or more. By having the TWA within the above numerical range, a composite nonwoven wiper with excellent water absorption performance can be obtained. The total water absorbance (TWA) of a composite nonwoven fabric is determined by cutting a wiper (composite nonwoven fabric) into a 76mm x 76mm square to prepare a sample, and measuring the dry weight of the sample. Next, the sample is immersed in distilled water for 2 minutes, and then suspended in a steam-saturated container with one corner of the sample as the upper apex, supported by this apex and two adjacent corners, in an extended state. After 30 minutes, the weight is measured after draining the water. Finally, the water retention capacity per gram of sample = water absorption (g / g) is calculated from the obtained measurement.

[0027] Furthermore, in the composite nonwoven fabric, the water absorption rate of the synthetic fiber side is preferably 1.0 seconds / 0.1 mL or less, and more preferably 0.7 seconds / 0.1 mL or less. By having the water absorption rate of the synthetic fiber side within the above numerical range, it is possible to create a composite nonwoven wiper that maintains overall water absorption performance while having a small difference in water absorption performance between the front and back sides. The water absorption rate of the pulp fiber surface is not particularly limited, but it is preferably 0.7 seconds / 0.1 mL or less.

[0028] Furthermore, the ratio of water absorption rates between the pulp fiber side and the synthetic fiber side (water absorption rate of the synthetic fiber side / water absorption rate of the pulp fiber side) is less than 1.30, and preferably between 0.85 and 1.10. By keeping the water absorption rate ratio within the above range, it is possible to create a composite nonwoven wiper that maintains overall water absorption performance while minimizing the difference in water absorption performance between the front and back sides. The water absorption rate, also known as the drip absorption rate, is measured in accordance with the drop method specified in JIS L 1907, measuring the time (in seconds) from when a 0.1 mL water droplet reaches the surface of the test specimen until the specular reflection of the specimen disappears.

[0029] (Unit embossing) In the composite nonwoven wiper according to this embodiment, horizontal diamond-shaped unit embossing 1 is processed in a pattern on both sides of the composite nonwoven fabric. Furthermore, the (embossed) convex portion 11 on one side and the (embossed) concave portion 12 on the other side of the unit embossing 1 correspond to each other on the front and back sides of the composite nonwoven fabric. Figure 1 is an enlarged view of the unit emboss 1 of the composite nonwoven wiper according to this embodiment, and Figure 2 is a view of Figure 1 from the back side of the composite nonwoven fabric. Hereinafter, the unit emboss 1 applied to the composite nonwoven wiper according to this embodiment will be described in detail with reference to Figures 1 and 2.

[0030] The shape of unit emboss 1 is a horizontal rhombus quadrilateral as shown in Figures 1 and 2. Preferably, the length of the diagonal in the CD direction (Y-axis direction in Figure 1) is equal to or greater than the length of the diagonal in the MD direction (X-axis direction in Figure 1). That is, (length of diagonal in MD direction) ≤ (length of diagonal in CD direction) is preferred. By making the unit emboss 1 a horizontal rhombus shape, the dirt-wiping performance of the composite nonwoven fabric wiper is improved. This is thought to be due to the combination of adjacent sides (reliefs) that form the rhombus. Furthermore, regarding the orientation of the rhombus, a horizontal rhombus shape that suppresses the lateral (CD) stretching of the wiper during wiping results in a composite nonwoven fabric wiper with superior dirt-wiping performance.

[0031] Furthermore, the depth of unit embossing 1 is 0.2 mm or more, preferably 0.4 mm or more. Also, the depth of unit embossing 1 is 2.0 mm or less, preferably 1.2 mm or less. By keeping the depth within the above numerical range, it is possible to create a composite nonwoven fabric wiper that maintains its texture while having a small difference in water absorption performance between the front and back sides, and also has excellent dirt-wiping properties. It is particularly suitable for wiping uneven surfaces with a lot of dirt.

[0032] The depth of the unit emboss 1 is measured using a 3D microscope. The measurement procedure is as follows: First, the portion with length L1 in Figure 2 is measured using a 3D microscope, and a curve S showing a cross-section of the composite nonwoven fabric as shown in Figure 3 is displayed. At this time, the portion with length L1 includes two valleys at both ends of one recess 22 and the peaks of the convex parts in the non-embossed region 3, so the curve S in Figure 3 also shows two valleys and two adjacent peaks. Figure 3 shows five height differences between peaks and valleys, labeled H1 to H5. Of these, the average of the height differences between the two valleys at both ends of the concave 22 and the peaks of the convex parts in the adjacent non-embossed areas 3 (which are H1 and H5 in Figure 3) is calculated and used as the depth of the unit emboss 1.

[0033] Note that the area of ​​one unit of embossing is 0.4 mm².2 It is preferably as described above. Further, the area of the unit emboss 1 is 40.0 mm 2 or less, which is preferable. By keeping the area within the above numerical range, it is possible to obtain a composite nonwoven fabric wiper that maintains water absorption performance, has a small difference in water absorption performance between the front and back, and is excellent in stain wiping performance. For the area of the unit emboss 1, first, in the recess 12 shown in FIG. 2 of the unit emboss 1, the length L2 of the diagonal line in the CD direction and the length L3 of the diagonal line in the MD direction are measured with a ruler. At this time, the measurement is performed so that both ends in the horizontal direction and the vertical direction of each of the recesses 12 are included. Then, "(length L2 × length L3) ÷ 2" is calculated as the area of the top surface.

[0034] In the unit emboss 1, the horizontal distance in the plane of the composite nonwoven fabric at the center points of the top surfaces of adjacent convex portions 11 is preferably 2.0 mm or more and more preferably 5.0 mm or more. Also, the horizontal distance in the plane of the composite nonwoven fabric is preferably 7.5 mm or less and more preferably 6.8 mm or less. By keeping the horizontal distance within the above numerical range, it is possible to obtain a composite nonwoven fabric wiper that maintains texture and is excellent in stain wiping performance. The horizontal distance in the plane of the composite nonwoven fabric at the center points of the top surfaces of adjacent convex portions 11 is measured as the distance D1 in FIG. 1 between the center points of adjacent convex portions 11 (in the direction parallel to the MD direction) in the unit emboss 1. When the center point is unclear, the distance between points corresponding to the same part of adjacent unit embosses 1 (in the direction parallel to the MD direction), such as D2, is measured instead of the distance between the center points.

[0035] <Method for manufacturing a composite nonwoven fabric wiper> The method for manufacturing the composite nonwoven fabric wiper according to the present embodiment is not particularly limited, and it can be manufactured by a known method for manufacturing a nonwoven fabric wiper. Examples of such a manufacturing method include, for example, (1) manufacturing of a composite nonwoven fabric, (2) embossing, (3) cutting and folding, and (4) packaging. However, some of the procedures may be in a different order.

[0036] In addition, in the manufacturing of the composite nonwoven fabric described in (1), the method of laminating and integrating the pulp fiber web onto the synthetic fibers may be, for example, water flow entanglement. The process of integration by water flow entanglement is described in detail, for example, in Japanese Patent Publication No. 6758116. [Examples]

[0037] The present invention will be described in more detail by the following examples and comparative examples, but the present invention is not limited in any way by the following examples.

[0038] Under the conditions shown in Tables 1 and 2, a pulp fiber web was laminated onto a spunbond nonwoven fabric containing polypropylene fibers, and the resulting composite nonwoven fabric, integrated by water entanglement, was embossed to create the wipers of Examples 1-6 and Comparative Examples 1-9. After preparation, the following evaluations were performed. The shape of the unit embossing was approximately circular (polka dot pattern) for Comparative Example 8 and square staggered (grid pattern) for Comparative Example 9. All other examples and comparative examples had a horizontal rhombus shape.

[0039] (Water absorption performance) The water absorption performance of the wipers (composite nonwoven fabric) was evaluated on a 5-point scale, based on the water absorption rate of the synthetic fiber surface of the manufactured wipers. 1: The water absorption rate of the synthetic fiber surface is greater than 1.2 seconds / 0.1 mL. 2: The water absorption rate of the synthetic fiber surface is greater than 1.0 seconds / 0.1 mL and less than or equal to 1.2 seconds / 0.1 mL. 3: The water absorption rate of the synthetic fiber surface is greater than 0.8 seconds / 0.1 mL and less than or equal to 1.0 seconds / 0.1 mL. 4. The water absorption rate of the synthetic fiber surface is greater than 0.6 seconds / 0.1 mL and less than or equal to 0.8 seconds / 0.1 mL. 5. The water absorption rate of the synthetic fiber surface is 0.6 seconds / 0.1 mL or less.

[0040] (Difference in water absorption performance between the front and back sides) The ratio of water absorption rates between the pulp fiber side and the synthetic fiber side of the manufactured wiper (composite nonwoven fabric) was evaluated on a 5-point scale. 1: The ratio of water absorption rates is 1.40 or higher. 2: The ratio of water absorption rates is 1.30 or more and less than 1.40. 3: The ratio of water absorption rates is 1.20 or more and less than 1.30. 4: The ratio of water absorption rates is 1.10 or more and less than 1.20. 5: The ratio of water absorption rates is less than 1.10.

[0041] (Wiper softness) Thirty monitors evaluated the softness of the composite nonwoven fabric (wiper) on a 5-point scale when holding it in their hands. 1: Composite nonwoven fabrics are stiff and have an inferior texture. 2: Composite nonwoven fabric is slightly stiff and has a slightly inferior texture. 3: The composite nonwoven fabric is moderately soft, and there are no particular issues with its texture. 4. The composite nonwoven fabric is soft and has a superior texture. 5: The composite nonwoven fabric is extremely soft and has a particularly excellent texture.

[0042] (Ease of wiping away dirt) Thirty monitors evaluated the dirt-wiping performance of a wiper (composite nonwoven fabric) on a 5-point scale when wiping dirt off a flat surface. 1: Dirt is difficult to wipe off, and the wipeability is poor. 2: Dirt is slightly difficult to wipe off, and the wipeability is somewhat inferior. 3: It is relatively easy to wipe away dirt and has a certain degree of wiping ability. 4: It is easy to wipe away dirt and has excellent wiping properties. 5: Dirt is easily wiped away, and it has excellent wipeability.

[0043] Table 1 shows the conditions and evaluation results for Examples 1-6, and Table 2 shows the conditions and evaluation results for Comparative Examples 1-9. If each evaluation score is 3 or higher, the product is acceptable. [Table 1]

[0044] [Table 2]

[0045] Based on the above, it was confirmed that this embodiment provides a composite nonwoven fabric wiper that maintains overall water absorption performance and texture while having minimal difference in water absorption performance between the front and back sides, and also exhibiting excellent dirt-wiping properties. [Explanation of symbols]

[0046] 1 unit embossed 2 Non-embossed areas 11 (Embossed) raised part 12 (Embossed) Recess

Claims

1. A wiper made of a composite nonwoven fabric having a synthetic fiber surface and a pulp fiber surface, formed by laminating and integrating a pulp fiber web onto a synthetic fiber, The basis weight of the aforementioned composite nonwoven fabric is 50 g / m². ２ 140g / m or more ２ The following: On both sides of the composite nonwoven fabric, a pattern of corresponding horizontal diamond-shaped unit embossing is processed, with the raised and recessed portions of the embossing corresponding on the front and back sides of the composite nonwoven fabric. The depth of the unit embossing is 0.2 mm or more and 2.0 mm or less. In the aforementioned unit embossing, the horizontal distance between the center points of the top surfaces of adjacent protrusions within the plane of the composite nonwoven fabric is 2.0 mm or more and 7.5 mm or less. A composite nonwoven wiper characterized in that the water absorption rate of the synthetic fiber surface in the composite nonwoven fabric is 1.0 seconds / 0.1 mL or less, and the ratio of the water absorption rates of the pulp fiber surface to the synthetic fiber surface (water absorption rate of the synthetic fiber surface / water absorption rate of the pulp fiber surface) is less than 1.

30.

2. The composite nonwoven fabric wiper according to claim 1, characterized in that the water absorption capacity (T.W.A.) per unit weight of the composite nonwoven fabric is 2.80 g / g or more.

3. The composite nonwoven fabric wiper according to claim 1, characterized in that the thickness of the composite nonwoven fabric is 1.50 mm / ply or less.

4. The composite nonwoven wiper according to claim 1, characterized in that the thickness of the composite nonwoven fabric is 0.40 mm / ply or more.

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