Non-woven fabric wiper

Abstract

To provide a nonwoven fabric wiper that achieves excellent liquid adsorptivity and high surface strength at low cost by setting the basis weight at a low level.SOLUTION: A nonwoven fabric wiper contains cellulosic fiber, synthetic fiber, and heat-fusing fiber. Content of the synthetic fiber is 1 wt.% or more and 50 wt.% or less of the total amount of the nonwoven fabric wiper, and content of the heat-fusing fiber is 10 wt % or more and 30 wt.% or less of the total amount of the nonwoven fabric wiper. The nonwoven fabric wiper has a basis weight of 25 g / m2 or more and 35 g / m2 or less, a thickness of 0.25 mm / 1 ply or more, a density of 0.080 g / cm3 or more and 0.130 g / cm3 or less, and a dry taber measurement value of 5 times or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a nonwoven fabric wiper. [Background technology]

[0002] Nonwoven wipers have traditionally been used in clean areas and other environments requiring low dust generation. While previously clean environments were limited to specific industrial sectors such as the semiconductor industry, in recent years, the introduction of clean environments has expanded to various industrial sectors, including cosmetics, pharmaceuticals, and food, leading to increased demand for nonwoven wipers. To accommodate diverse wiping environments, industrial nonwoven wipers are manufactured using, for example, cellulose fibers (wood pulp, viscose rayon, lyocell, etc.) and synthetic short fibers (PET, PP, PE, etc.) via wet or spunlace processes.

[0003] Patent Document 1 describes a wet papermaking process using wood pulp, heat-fusible fibers, rayon fibers, vinylon binder fibers, and a paper strength enhancer, resulting in a paper with a basis weight of 10 g / m². 2 More than 30g / m 2 The following describes a wet-laid nonwoven wiper base fabric containing 50-85% by weight of wood pulp, 10-50% by weight of rayon fibers, and 1-3% by weight of heat-fusible fibers, and also containing 1-15% by weight of vinylon binder fibers per 100% by weight of these fibers. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 3798372 [Overview of the project] [Problems that the invention aims to solve]

[0005] In the manufacturing of cosmetics, food products, and other products, it is common practice to increase the thickness of nonwoven wipers to further improve their liquid absorption. However, while liquid absorption improves, surface abrasion resistance decreases, making it difficult to obtain sufficient strength when wiping with highly viscous substances such as oil. Furthermore, increasing the amount of hydrophilic cellulose fibers presents challenges such as increased manufacturing costs.

[0006] The objective of the present invention is to provide a nonwoven wiper that is low-cost, achieves both excellent liquid absorption and high surface strength by setting a low basis weight. [Means for solving the problem]

[0007] The inventors of this invention conducted extensive research to solve the above problems and, as a result, discovered that a desired nonwoven wiper could be obtained at low cost by setting a low basis weight and adjusting the blending ratio (content) of synthetic fibers and heat-fusible fibers, as well as the density of the nonwoven wiper, thus completing the present invention. That is, the present invention relates to the following nonwoven wiper.

[0008] (1) A nonwoven wiper containing cellulose fibers, synthetic fibers, and heat-fusible fibers, The content of the synthetic fibers is 3% by weight or more and 50% by weight or less of the total amount of the nonwoven wiper, and the content of the heat-fusible fibers is 10% by weight or more and 30% by weight or less of the total amount of the nonwoven wiper. Weight: 25g / m 2 More than 35g / m 2 Below are the specifications for materials with a thickness of 0.25 mm / 1ply or more and a density of 0.080 g / cm³. 3 More than 0.130g / cm 3 The following are nonwoven wipers with a dry taper measurement of 5 or more times. (2) The nonwoven wiper described in (1) above, having a wet relative tensile strength (GMT) of 5.5 N / 25 mm or more and 20.0 N / 25 mm or less. (3) Water absorption rate of 20 seconds or less, oil absorption rate of 260 seconds or less, TWA of 170 g / m² 2 In summary, TOA is 170g / m² 2The non-woven wiper as described above in (1) or (2). (4) The non-woven wiper according to any one of (1) to (3) above, wherein the synthetic fiber is a thermoplastic resin fiber and the heat-fused fiber is a core-sheath type composite fiber.

Advantages of the Invention

[0009] According to the present invention, by setting a low basis weight, a non-woven wiper is provided which is low in cost and has both excellent liquid absorbency and high surface strength.

Brief Description of the Drawings

[0010] [Figure 1] It is a side view schematically showing an embodiment of a method for manufacturing the non-woven wiper of the present embodiment. [Figure 2] It is a photograph showing the surface state of the non-woven wiper of the present embodiment after a dry wiper test.

Modes for Carrying Out the Invention

[0011] <Non-woven wiper> The non-woven wiper according to the present embodiment contains cellulose-based fibers, synthetic fibers, and heat-fused fibers, and has a basis weight in the range of 25 g / m 2 or more and 35 g / m 2 or less, a thickness in the range of 0.25 mm / 1 ply or more, a density in the range of 0.080 g / cm 3 or more and 0.130 g / cm 3 or less, and a dry wiper measurement value of 5 times or more. Such a non-woven wiper has a good balance of liquid absorbency and surface strength and can be suitably used as a wiping wiper in various industrial fields.

[0012] According to this embodiment, instead of using a method that increases the basis weight to maintain strength and liquid absorption, strength and liquid absorption can be maintained at low cost while maintaining the basis weight by appropriately blending heat-fusible fibers. More specifically, in order to improve the strength of the nonwoven wiper, the blending ratio (content) of synthetic fibers is increased, the decrease in liquid absorption due to the increase in the blending ratio of synthetic fibers is maintained by adjusting the density of the nonwoven fabric to a lower level, and the decrease in surface strength due to the decrease in density is maintained by blending heat-fusible fibers, resulting in a nonwoven wiper with maintained strength.

[0013] <Raw materials for nonwoven wipers> As described above, the nonwoven wiper of this embodiment is composed of a predetermined amount of synthetic fibers and a predetermined amount of heat-fusible fibers, with the remainder being cellulose fibers. Hereinafter, each fiber will be described in detail in the order of cellulose fibers, synthetic fibers, and heat-fusible fibers.

[0014] (Cellulose fiber) Cellulosic fibers, for example, impart water absorption, oil absorption, etc., to the nonwoven wiper of this embodiment. As cellulose fibers, general cellulose fibers such as lyocell, viscose rayon, copper ammonia rayon, solvent-spun cellulose fiber rayon, cotton fiber, bleached softwood kraft pulp (hereinafter also referred to as "NBKP"), and bleached hardwood kraft pulp (hereinafter also referred to as "LBKP") can be used. The content ratio of NBKP to LBKP in the cellulose fibers is, for example, in the range of NBKP:LBKP = 50:50 to 100:0, in the range of NBKP:LBKP = 70:30 to 100:0, in the range of NBKP:LBKP = 90:10 to 100:0, or NBKP:LBKP = 100:0. As NBKP, fibers made from radiata pine, slush pine, southern pine, lodgepole pine, spruce, and Douglas fir are preferred. Furthermore, NUKP can be used instead of NBKP, and LUKP can be used instead of LBKP. Among these, lyocell and viscose rayon are preferred. Cellulose fibers can be used individually or in combination of two or more types.

[0015] (Heat-fusible fibers) By incorporating heat-fused fibers, for example, the decrease in surface strength due to a decrease in density of the nonwoven wiper of this embodiment is prevented, the wet strength is improved, and the oil absorption capacity is increased by increasing bulk. The increased bulk also contributes to an improvement in oil absorption capacity. Furthermore, the binding effect due to fusion can suppress dust generation. In the nonwoven wiper of this embodiment, the heat-fused fiber content is in the range of 10% to 30% by weight, 15% to 25% by weight, or 18% to 22% by weight of the total amount of the nonwoven wiper of this embodiment. When the heat-fused fiber content is less than 10% by weight, the oil wiping performance is relatively good and there is little stiffness, but the dry taper is less than 5 times, the abrasion resistance is low, and the wiping performance of highly viscous substances and water tends to decrease. On the other hand, when the heat-fusible fiber content exceeds 30% by weight, while the abrasion resistance, wiping ability of highly viscous substances, and dust generation of the nonwoven wiper improve, the wiping ability of water and oil decreases, the stiffness increases, and it tends not to be possible to obtain a nonwoven wiper with a good overall balance.

[0016] Heat-fusible fibers are thermoplastic resin fibers with a melting point in the range of 100°C to 200°C. Such thermoplastic resin fibers can be used without particular limitation as long as their melting point falls within the aforementioned range. Examples include polyolefin fibers such as polyethylene (PE) and polypropylene (PP), polyester fibers such as polyester, polyamide fibers such as nylon 6 and nylon 66, and polyacrylic fibers such as polyacrylic acid and polyalkyl methacrylate. Furthermore, composite fibers consisting of two or more components, including a low-melting-point component and a high-melting-point component, can be used as heat-fusible fibers. Examples of such composite fibers include core-sheath type composite fibers. Preferably, the core is made of high-melting-point PET or PP, and the sheath is made of low-melting-point PET, PP, or PE. Examples of core-sheath type composite fibers include concentric core-sheath type composite fibers and eccentric core-sheath type composite fibers. Specific examples of these composite fibers are described in Japanese Patent Publication No. 9-296325 and Japanese Patent Publication No. 2759331, among others. Furthermore, commercially available heat-fusible fibers can also be used, including the ES Chop series (manufactured by Chisso Corporation) and the NBF series (manufactured by Daiwa Spinning Co., Ltd.). In particular, the E-type of NBF is suitable because it uses EVA (ethylene-vinyl acetate copolymer) with a low melting point (approximately 100°C) as the sheath component, allowing for simultaneous drying and fusion during the drying process during papermaking, thus simplifying the operating process. Among these heat-fusible fibers, core-sheath type composite fibers are preferred, and PE / PET type composite fibers are more preferred.

[0017] (Synthetic fiber) Synthetic fibers, for example, improve the strength of the nonwoven wiper in this embodiment. The synthetic fiber content is in the range of 3% to 50% by weight, 10% to 40% by weight, or 20% to 30% by weight of the total amount of the nonwoven wiper in this embodiment. If the synthetic resin is less than 1% by weight, the stiffness is relatively low, but the abrasion resistance, the ability to wipe high-viscosity substances and oils, and the dust generation tend to decrease. On the other hand, if the synthetic resin exceeds 50% by weight, the abrasion resistance and the ability to wipe high-viscosity substances and oils improve, but the water wiping ability decreases significantly, and the stiffness tends to appear.

[0018] Synthetic fibers are thermoplastic resin fibers with a melting point of 200°C or higher. Examples of such thermoplastic resin fibers include polyolefin fibers such as polyethylene (PE) and polypropylene (PP), polyester fibers such as polyethylene terephthalate (PET), polyamide fibers such as nylon 6 and nylon 66, polyacrylic fibers such as polyacrylic acid and polyalkyl methacrylate, and vinyl chloride fibers such as polyvinyl chloride and polyvinylidene chloride. Among these, polyester fibers and polyolefin fibers are preferred, and PP, PE, and PET are more preferred. Synthetic fibers can be used individually or in combination of two or more types. By using predetermined amounts of cellulose fibers, heat-fusible fibers, and synthetic fibers as described above to manufacture a nonwoven fabric, a nonwoven wiper having the following physical properties can be obtained.

[0019] <Physical properties of nonwoven wipers> Next, the physical properties of the nonwoven wiper according to this embodiment will be described in more detail, in the following order: basis weight, thickness, density, dry taper measurement value, wet relative tensile strength (GMT), water absorption rate, oil absorption rate, water retention capacity (TWA), and oil absorption capacity (TOA).

[0020] (Inspector) The basis weight (grammage) of the nonwoven wiper according to this embodiment is 25 g / m². 2 More than 35g / m 2 Within the following range, 27g / m² 2 More than 33g / m 2 The following ranges, or 28 g / m² 2 More than 32g / m 2 The following range applies. Because the weight is within the aforementioned range, it is strong, tear-resistant, soft, and not stiff, resulting in good adhesion and excellent wiping performance. Weight: 25g / m² 2 Below a certain weight, abrasion resistance decreases, and the ability to wipe away highly viscous substances, water, and oil tends to decline. 2Beyond a certain point, while abrasion resistance and the ability to wipe away high-viscosity substances, water, and oil improve, the texture becomes very rough, and dust generation tends to decrease significantly. The basis weight of nonwoven wipers is measured in accordance with JIS P 8124.

[0021] (Thickness) The thickness of the nonwoven wiper according to this embodiment is in the range of 0.25 mm / 1ply or more, in the range of 0.26 mm / 1ply to 0.40 mm / 1ply, or in the range of 0.28 mm / 1ply to 0.32 mm / 1ply. By adjusting the thickness to the above range, for example, it is possible to improve wiping performance while achieving both high strength and low stiffness. If the thickness is less than 0.25 mm / 1ply, the low thickness tends to reduce the ability to remove water and oil, and it also tends to become more difficult to wipe away highly viscous substances. The thickness is measured using a thickness gauge (Ozaki Seisakusho, dial thickness gauge "PEACOCK").

[0022] (density) The density of the nonwoven wiper according to this embodiment is 0.080 g / cm³. 3 More than 0.130g / cm 3 Within the following range, 0.090 g / cm³ 3 More than 0.120g / cm 3 Within the following range, or 0.100 g / cm³ 3 More than 0.110g / cm 3 The following range applies. When the density is within the aforementioned range, the wiping performance of the nonwoven wiper improves, and the wiping performance, especially against water and oil, is significantly improved. Density: 0.080 g / cm³ 3 Below a density of 0.130 g / cm³, abrasion resistance, the ability to wipe away highly viscous substances and oils, and dust generation tend to decrease. 3 Beyond a certain point, the ability to wipe away water, oil, etc. tends to decrease. Density is calculated from the base weight and thickness.

[0023] (DryTaber measurement) The dry taper measurement value of the nonwoven wiper according to this embodiment is in the range of 5 or more times, 5 to 15 times, or 5 to 12 times. The dry taper measurement value being within the aforementioned range indicates the abrasion resistance of the nonwoven wiper and its ability to wipe highly viscous substances, water, oil, etc. Improvements are expected. When the dry taper measurement is less than 5 times, wear resistance, wiping ability for highly viscous substances and water tend to decrease. Also, when the dry taper measurement is 15 times or more, the roughness increases, and the wiper's usability tends to decrease.

[0024] In a preferred embodiment, the nonwoven wiper of this embodiment has a wet relative tensile strength (GMT) in the range of 5.5 N / 25 mm to 20.0 N / 25 mm, 6.0 N / 25 mm to 15.0 N / 25 mm, or 8.0 N / 25 mm to 13.0 N / 25 mm. By setting the wet relative tensile strength (GMT) within the aforementioned ranges, the nonwoven wiper of this embodiment achieves a good balance of excellent abrasion resistance and wiping ability, softness, and low dust generation. When the wet relative tensile strength (GMT) is less than 5.5 N / 25 mm, the abrasion resistance and wiping ability of the nonwoven wiper to remove highly viscous substances and oils tend to decrease, and when the wet relative tensile strength (GMT) exceeds 20.0 N / 25 mm, the nonwoven wiper tends to become stiff and dust generation decreases significantly. The wet relative tensile strength (GMT) is measured according to JIS P8113.

[0025] (Water absorption rate) In a preferred embodiment, the nonwoven wiper of this embodiment has a water absorption rate in the range of 20 seconds or less, or 8 seconds or less. Having a water absorption rate within the aforementioned range improves the wiping performance, particularly for water and oil, in various industrial fields, resulting in a highly effective nonwoven wiper. If the water absorption rate exceeds 20 seconds, there is a tendency for abrasion resistance and the wiping performance for water, oil, etc., to decrease. The water absorption rate is measured based on the water absorption rate test specified in JIS L 1907.

[0026] (Oil absorption speed) In a preferred embodiment, the nonwoven wiper of this embodiment has an oil absorption rate in the range of 260 seconds or less, or 200 seconds or less. Having an oil absorption rate within the aforementioned range improves the wiping performance, particularly for water and oil, in various industrial fields, resulting in a highly effective nonwoven wiper. When the oil absorption rate exceeds 260 seconds, the wiping performance for water, oil, etc., tends to decrease. The oil absorption rate is measured using oil instead of water in the water absorption rate test specified in JIS L 1907.

[0027] (Water retention capacity (TWA)) In a preferred embodiment, the nonwoven wiper of this embodiment has a water retention capacity (TWA) of 170 g / m². 2 Within the above range, or 200g / m² 2 The above range applies. By setting the water retention capacity within the aforementioned range, the nonwoven wiper becomes highly effective in various industrial fields, particularly in wiping away water and oil, resulting in a highly clean wiper. Water retention capacity: 170 g / m² 2 If the value is less than this, the abrasion resistance or wiping performance of the nonwoven wiper of this embodiment tends to decrease.

[0028] (Oil absorption amount (TOA)) In a preferred embodiment, the nonwoven wiper of this embodiment has an oil absorption capacity (TOA) of 170 g / m². 2 Within the above range, or 200g / m² 2 The above range applies. By setting the oil retention capacity within the aforementioned range, the nonwoven wiper becomes highly effective in various industrial fields, particularly in wiping away water and oil, resulting in a highly clean wiper. Oil retention capacity: 170 g / m² 2 If the value is less than this, the abrasion resistance or wiping performance of the nonwoven wiper of this embodiment tends to decrease.

[0029] <Manufacturing method for nonwoven wipers> The nonwoven wiper according to this embodiment can be manufactured according to a conventionally known method for manufacturing spunlace nonwoven fabrics, and can be obtained as a spunlace nonwoven fabric. Figure 1 shows one embodiment of a method for manufacturing spunlace nonwoven fabric, which includes a web manufacturing step, a water flow entanglement step, and a drying step.

[0030] In the web production process, predetermined amounts of cellulose fibers, synthetic fibers, and heat-fusible fibers are passed through a carding machine 10 to obtain a fiber web. The obtained fiber web is then transported to a water entanglement process.

[0031] In the water entanglement process, a high-pressure water stream is injected from water jet nozzles 11 positioned almost perpendicular to the fiber web above it, causing the fibers within the fiber web to become entangled. In this embodiment, there are four water jet nozzles 11, but the invention is not limited to this embodiment and any number of nozzles can be used. Here, the hole diameter φ of the water jet nozzles 11 is, for example, in the range of 0.06 mm to 0.15 mm, or 0.10 mm to 0.12 mm. The distance between two adjacent water jet nozzles 11 is, for example, in the range of 0.4 mm to 1.0 mm. The water pressure for the water entanglement process is set according to the basis weight of the fiber web, for example, in the range of 1 MPa to 30 MPa. After water entanglement is performed, a fiber web in which each fiber is entangled is obtained, and this fiber web is transported to the drying process.

[0032] In the drying process, the fiber web, in which the aforementioned fibers are intertwined, is dried in the dryer 12 to obtain the nonwoven wiper of this embodiment as a spunlace nonwoven fabric. By using a predetermined amount of cellulose fibers, synthetic fibers, and heat-fusible fibers, and by setting the hole diameter φ of the water jet nozzle 11, the spacing between the water jet nozzles 11, and the water pressure of the water flow entanglement treatment to the aforementioned ranges, a spunlace nonwoven fabric having the predetermined characteristics of this embodiment can be obtained. Here, the drying conditions are not particularly limited, but for example, drying can be carried out at a temperature of 80°C to 180°C for a period of 1 minute to 20 minutes. Furthermore, it is preferable to carry out a heat press part (heat calender, etc.) at a temperature of 80°C to 180°C.

[0033] Although the present invention has been described above using embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope of the invention described in the above embodiments, and it will be clear to those skilled in the art that various modifications or improvements can be made to the above embodiments. Furthermore, it is clear from the claims that embodiments with such modifications or improvements may also be included in the technical scope of the present invention. [Examples]

[0034] The embodiment will be described in more detail below with reference to examples and comparative examples.

[0035] (Examples 1-7 and Comparative Examples 1-8) Spunlace nonwoven fabrics were prepared using viscose rayon (cellulose fiber), polyethylene terephthalate fiber (synthetic fiber), and PE / PET core-sheath fiber (heat-fusible fiber) in the proportions (weight %) shown in Table 1, and nonwoven wipers were made for Examples 1-7 and Comparative Examples 1-8. The obtained nonwoven wipers were evaluated as follows. The results are shown in Table 1.

[0036] [Measurement method] The following tests were performed on each nonwoven wiper obtained in Examples 1-7 and Comparative Examples 1-8. (Weight) Measured in accordance with JIS P 8124. The thickness was measured using a thickness gauge (Ozaki Seisakusho, dial thickness gauge "PEACOCK"). With a measuring load of 3.7 kPa and a probe diameter of 30 mm, the sample (nonwoven wiper, 1 ply) was placed between the probe and the measuring stand, and the gauge was read when the probe was lowered at a speed of 1 mm or less per second. The measurement was repeated 10 times and the average value was calculated. (Density) Calculated from basis weight and thickness. (Surface Strength) A dry Taber test was conducted. In the dry Taber test, a Taber-type abrasion tester (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name: Rotary Abrasion Tester TS-2) was used, and two abrasion wheels: CS-0 / S-32 (Rubber) were mounted opposite each other at a predetermined location on the top of the machine. The sample (nonwoven wiper) was placed between the two abrasion wheels, and the two abrasion wheels were rotated a predetermined number of times. The contact surface of the sample (nonwoven wiper) with the two abrasion wheels was visually observed, and the number of rotations until fraying occurred was measured. (Wet Tensile Strength) The tensile strength in the longitudinal and transverse directions when wet was measured according to JIS P8113. (Water absorption rate) The water absorption rate was determined in accordance with the water absorption rate test specified in JIS L1907, by measuring the time (in seconds) from when a 0.1 ml water droplet reached the surface of the test specimen until the specular reflection of the test specimen disappeared. (Oil absorption rate) The oil absorption rate was measured in the same way as the water absorption rate, except that oil was used instead of water. Machine oil (product name: FBK-100, manufactured by ENEOS Corporation) was used. (Water retention capacity, TWA) A sample is prepared by cutting a nonwoven fabric into a 75mm x 75mm square, and its dry weight (W1) is measured. Next, this sample is immersed in distilled water for 2 minutes, and then suspended in a container saturated with water vapor (100% RH) with one corner of the sample as the upper apex, supported by this apex and the two adjacent corners, in an extended state. After 30 minutes, the weight (W2) is measured. The measured value (W2 - W1) is then calculated per meter of the sample. 2 Water retention capacity per unit (g / m³) 2 Convert to ). (TOA, Oil Absorption) The oil absorption was measured in the same way as in the TWA measurement, except that oil was used instead of distilled water. Nippon Oil Machinery Oil (FBK-100) was used as the oil. (Abrasion Resistance) The dry taber test described above was performed and evaluated according to the following criteria. Figure 2 shows the surface condition of the nonwoven wiper after the dry taber test was performed on the nonwoven wiper of this embodiment. In this photograph, no fuzzing has occurred in the central part. If the number of cycles until pilling occurs is less than 2, it is marked as "1". If the number of times before pilling occurs is 2 or more but less than 5, it is classified as "2". If the number of cycles until pilling occurs is 5 or more but less than 8, it is classified as "3". If the number of cycles until pilling occurs is 8 or more but less than 11, it is classified as "4". Items that require 11 or more cycles before pilling are marked with "5". (Wiping Performance) Ten monitors sprayed a high-viscosity substance (such as glue or adhesive), water, or oil onto a flat surface and wiped it with a nonwoven wiper, evaluating the ease of wiping on a 5-point scale. A "5" meant that the object to be wiped could be completely wiped away with one or two wipes, and the nonwoven wiper did not tear. A "4" meant that the object to be wiped away could be almost completely wiped away with multiple wipes, and the nonwoven wiper tore slightly. A "3" meant that even after wiping multiple times, a small amount of the object to be wiped away remained, and the nonwoven wiper tore relatively noticeably. A "2" meant that even after wiping multiple times, the object to be wiped away could not be sufficiently wiped away, and the nonwoven wiper tore noticeably. A "1" meant that even after repeated wiping, the nonwoven wiper tore a lot, and the object to be wiped away could not be sufficiently wiped away. (Roughness) Ten monitors evaluated the tactile feel of the nonwoven wiper according to the following criteria: "4" is soft and smooth, "3" is relatively soft but with a slight roughness, "2" is hard and rough, and "1" is hard and rough. (Dust-generating) The self-dusting properties of nonwoven wipers were evaluated. Using the tumbling method of JIS B 9923, nonwoven wipers measuring 250 mm x 250 mm were induced to generate dust, and the number of dust particles with a diameter of 0.3 μm to 5 μm in 10 L of the generated air was measured using a particle counter (product name: KC-03B, manufactured by Rion Co., Ltd.). The number of dust particles generated per nonwoven wiper of the aforementioned size was determined and evaluated according to the following criteria. Items with 1100 or more dust particles are marked "1". If the number of dust particles generated is 800 or more but less than 1100, it is classified as "2". Items with 500 or more dust particles but less than 800 are classified as "3". Items with 100 or more but less than 500 dust particles are classified as "4". Items with 100 or fewer dust particles are marked with "5".

[0037] [Table 1]

[0038] The nonwoven wipers of Examples 1 to 7 possess a good balance of characteristics, including abrasion resistance, ability to wipe high viscosity substances, water, and oil, a smooth and soft feel (without any roughness), and low dust generation (less dust generation), making them suitable for use as nonwoven wipers for cleaning in various industrial fields.

[0039] (Comparative Example 1) Due to its low basis weight, it has poor liquid absorption, wipeability, and surface strength. (Comparative Example 2) The basis weight is too high, resulting in a rough texture and a tendency to generate dust. (Comparative Example 3) Due to its low thickness and high density, it has poor wiping properties. (Comparative Example 4) Due to its excessive thickness, it has low surface strength and dust generation. (Comparative Example 5) Due to the low dry taber value, the surface strength and dust generation are low. (Comparative Example 6) The proportion of synthetic resin is too high, resulting in poor water-wiping properties and a rough texture. (Comparative Example 7) Due to the low ratio of heat-fused fibers, the surface strength and dust generation are low. (Comparative Example 8) Due to the high ratio of heat-fused fibers, it has poor water-wicking properties and a rough texture. [Explanation of symbols]

[0040] 10 card machines 11 Water jet nozzle 12 Dryer

Claims

1. A nonwoven wiper containing cellulose fibers, synthetic fibers, and heat-fusible fibers, The aforementioned synthetic fiber is Thermoplastic resin fibers with a melting point of 200°C or higher, The content is 3% by mass or more and 50% by mass or less of the total amount of the nonwoven wiper. The heat-fusible fibers are A thermoplastic resin fiber with a melting point of 100°C or higher and less than 200°C, a core-sheath type composite fiber made of PE / PET, The content is 10% by mass or more and 30% by mass or less of the total amount of the nonwoven wiper. Weight: 25 g / m ２ 35g / m or more ２ Below are the specifications for thicknesses of 0.25 mm / 1 ply or more and density of 0.080 g / cm³. ３ 0.130g / cm or more ３ The following are nonwoven wipers with a dry taper measurement of 5 or more times.

2. A nonwoven wiper according to claim 1, wherein the wet relative tensile strength (GMT) is 5.5 N / 25 mm or more and 20.0 N / 25 mm or less.

3. A nonwoven fabric wiper according to claim 1 or claim 2, wherein the water absorption speed is 20 seconds or less and the oil absorption speed is 260 seconds or less.

4. A nonwoven wiper according to any one of Claims 1 to 3, wherein T.W.A. is 170 g / m² or more and T.O.A. is 170 g / m² or more.

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