Description

APPARATUS FOR PERFORATING NONWOVEN WEB AND METHOD THEREOF, NONWOVEN WEB BY THE SAME

Technical Field

[1] The present invention relates to an apparatus for perforating non-woven fabric, a method of perforating non-woven fabric, and non- woven fabric prepared by the apparatus and method. In more particular, the present invention relates to an apparatus for perforating non- woven fabric which can easily and rapidly form a plurality of apertures in the surface of non- woven fabric and which thus improves cost efficiency, a method of perforating non- woven fabric, and a non- woven fabric prepared using the same apparatus and employing the same method. Background Art

[2] Non- woven fabric is fabric produced by arranging fibers parallel to each other or in irregular directions and combining the arranged fibers together into a sheet shape using synthetic resin adhesive instead of employing a weaving processing or a knitting process. The material for the non-woven fabric was cotton in early years, but synthetic resin, such as polypropylene and nylon, has been used since the mid- 1950.

[3] There are a few non-woven fabric processing methods, including a thermal bonding process in which fibers are formed by extruding synthetic resin through nozzles and the fibers are thermally bonded, a dipping process, and a dry process. The dipping process is also called a paper manufacturing type process. That is, fibers are dipped into and thus wet with synthetic resin adhesive and then dried with heat, so that the product is similar to paper. In the dry process, synthetic resin is ejected to thin cotton- shaped fibers and then the fibers and resin are dried with heat. Since the mid- 1950, non- woven fabric has been developed rapidly in America and used for various purposes since the non- woven fabric has no directionality and the edges, when cut, do not fray due to the tangling of fibers. Further, non- woven fabric is used industrially nowadays. Recently, non-woven fabric produced by the thermal bonding process, in which synthetic resin is extruded through nozzles to produce fibers and the fibers are thermally bonded, is the most widely used.

[4] On the other hand, recently non- woven fabric for a lining is applied to a part which directly contacts body parts, such as disposable sanitary napkins, diapers, etc. Such non- woven fabric for lining must have a soft texture and a beautiful appearance and must be hygroscopic and cushiony, and thus is expensive to manufacture. Further, as cleaning cloths, products for absorbing sweat from the forehead of people who exercise, and products which are used in a state of being in contact with a body part or

being attached to a body part, the use of the perforated non-woven fabric will be increased.

[5] In particular, EP 0472992 discloses perforated non-woven fabric having increased hygroscopic and cushiony characteristics in comparison with normal non- woven fabric by forming a plurality of apertures in the normal non- woven fabric.

[6] EP 0472992 discloses a structure in which non- woven fabric passes through gaps between a first roller, having a plurality of pins, and a second roller, having a plurality of grooves, so that a plurality of apertures is formed in the non- woven fabric by the penetration of the pins, and the perimeters of the apertures bulge.

[7] The perimeters of the apertures of the non-woven fabric bulge because the pins are overheated in order to form the apertures in the non- woven fabric through a single action of penetration of the pins. For this reason, the peripherals of the apertures of the non- woven fabric are easily thermally cured, and thus the surface of the non- woven fabric becomes rough, and the cushiony characteristic is deteriorated.

[8] The known technique has disadvantages of low productivity and low cost efficiency because it is difficult to increase the rotation speed of the first and second rollers to 20m/min or more in order to improve the appearance of the apertures, the hygroscopic property, and the cushiony property.

[9] Accordingly, the productivity of the perforated non- woven fabric is low in the case in which only one second roller is installed with respect to one first roller (pin roller). On the other hand, when the operation speed is increased for high productivity, the quality of the perforated non- woven fabric is deteriorated.

[10] According to the known technique, it is possible to precisely form the apertures in the non- woven fabric when the pins of the first roller and the grooves of the second roller are precisely aligned. Accordingly, the pins and grooves must be precisely processed to have accurate dimensions, which results in an increase in the cost of manufacturing the first and second rollers. That is, a large amount of money is consumed in the process of perforating the non- woven fabric, and thus cost efficiency becomes low.

[11] For the above-mentioned reasons, the perforated non- woven fabric is expensive due to low productivity, and thus the non- woven fabric is not widely used, even though it has many advantages. Disclosure of Invention Technical Problem

[12] The invention is conceived in order to solve the above-mentioned problems of the known technique, and an object of the invention is to provide an apparatus for perforating non- woven fabric, which is capable of rapidly forming a plurality of apertures in the non-woven fabric at lost cost, i.e. which has increased productivity and

cost efficiency, a method of perforating non-woven fabric, and a non-woven fabric prepared employing the same apparatus and method.

[13] A further object of the invention is to provide an apparatus for perforating non- woven fabric, which is capable of improving softness, the cushiony property, the hygroscopic property, and the washability of the non- woven fabric, a method of perforating non-woven fabric, and a non-woven fabric prepared employing the same apparatus and method.

[14] A still further object of the invention is to provide an apparatus for perforating non- woven fabric and a method of perforating non- woven fabric, the apparatus and the method being capable of improving quality, productivity, and cost efficiency of a perforated non- woven fabric used in a state of being in direct contact with or directly attached to a body part. Technical Solution

[15] In order to accomplish the objects of the invention, according to one aspect of the invention, there is provided an apparatus for perforating non- woven fabric including a first roller having a plurality of pins formed on the surface thereof and being rotatable, and two or more second rollers which are arranged on the outer circumferential surface of the first roller in a circumferential direction and which rotate relative to the outer circumferential surface of the first roller.

[16] In the apparatus, it is preferable that each of the second rollers have a plurality of grooves, each having an inner diameter larger than that of each of the pins of the first roller.

[17] In the apparatus, it is preferable that each of the second rollers have a brush on the outer surface thereof.

[18] In the apparatus, it is preferable that the outer surface of each of the second rollers be made of an elastic material or a material having a plurality of pores therein.

[19] According to another aspect of the invention, there is provided a method of perforating non- woven fabric including a step of preparing one or more rolls of non- woven fabric, a step of preparing a first roller having a plurality of pins and two or more second rollers arranged on the outer surface of the first roller, and a step of allowing the respective rolls of non- woven fabric to pass through corresponding gaps between the first roller and the corresponding second rollers, which are rotating.

[20] According to a further aspect of the invention, there is provided a method of perforating non- woven fabric including a step of preparing a roll of non- woven fabric, a step of preparing a first roller having a plurality of pins and two or more second rollers arranged on the outer surface of the first roller, and a step of allowing the roll of non- woven fabric to sequentially pass through gaps between the first roller and the

second rollers so that the non-woven fabric is perforated two or more times.

[21] According to a still further aspect of the invention, there is provided a method of perforating non- woven fabric including a step of preparing one or more rolls of non- woven fabric, a step of preparing two or more opposing roller groups, each opposing roller group including two or more second rollers provided on the outer surface of the first roller, and a step of allowing the respective rolls of non- woven fabric to sequentially pass through corresponding gaps between the first roller and the second rollers.

[22] In the method, it is preferable that the first roller rotate at a speed in the range from 1 to 150 m/min, and more preferable that the first roller rotate at a low speed in the range from 1 to 50 m/min, taking the criteria for non- woven fabric for personal goods into consideration.

[23] According to a yet further aspect of the invention, there is provided a non- woven fabric with a plurality of apertures which is prepared by employing the apparatus for and method of perforating non- woven fabric.

[24] In the non- woven fabric, it is preferable that the total area of the apertures be about

60% of the entire surface area thereof, and that the density of the apertures be I/inch or more. It is more preferable that the total area of the apertures be about 1 to 50% of the entire surface area thereof, and that the density of the apertures be about 30/inch or more.

[25] In the non- woven fabric, it is preferable that the non-woven fabric be a product which directly contacts a body part of a human or a patch which is directly attached to a product that directly contacts a body part of a human.

[26] It is preferable that the non- woven fabric be used as a lining of a disposal sanitary napkin or a disposal diaper.

[27] It is preferable that the non- woven fabric be applied as a cleaning cloth or an agricultural product.

[28] The features and advantages of the invention will be apparent from the following description with reference to the accompanying drawings. The terms used in the specification and claims of the invention may not be intended to refer exclusively to dictionary definitions, but may be intended to refer to meanings and concepts defined in accordance with the technical spirit of the invention on the grounds that an inventor can act as his or her own lexicographer in order to explain his or her invention in the best way.

Advantageous Effects

[29] The invention is advantageous in that it is possible to rapidly form a plurality of apertures in the surface of a non- woven fabric at low cost, and thus it is possible to

improve the productivity and cost efficiency of a perforated non-woven fabric. [30] The invention is further advantageous in that it is possible to improve smoothness, the cushiony property, the washability, and the hygroscopic property of non-woven fabric.

Brief Description of the Drawings [31] FIG. 1 is a view illustrating an apparatus for perforating non- woven fabric according to a first embodiment of the invention;

[32] FIG. 2 is an enlarged sectional view illustrating part A in FIG. 1 ;

[33] FIG. 3 is an enlarged sectional view illustrating part "A" shown in FIG. 2, according to another embodiment; [34] FIG. 4 is a view illustrating an apparatus for perforating non- woven fabric according to a second embodiment of the invention; [35] FIG. 5 is a view illustrating an apparatus for perforating non-woven fabric according to a third embodiment of the invention; and

[36] FIG. 6 is a sectional view illustrating non- woven fabric according to the invention.

[37] * Brief Description of Reference Numerals of Key Elements in the Drawings *

[38] 10: Apparatus for perforating a non-woven fabric

[39] 11 : First roller 12: Second roller

[40] 15: Pin

Mode for the Invention [41] The above-mentioned objects, features, and advantages of the invention will be more apparent with reference to the following description. [42] Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. [43] First, it is noted that like elements or parts in the drawings are referred to using like reference numbers. While describing the invention, known functions or structures related to the invention will be omitted in order to avoid obscuring the spirit of the invention. [44] FIG. 1 shows an apparatus for perforating non- woven fabric according to a first embodiment of the invention, and a method of perforating non- woven fabric. [45] As shown in the figures, an apparatus 10 for perforating non-woven fabric according to a first embodiment includes a first roller 11 having a plurality of pins 15 and two or more section rollers arranged on the outer circumferential surface of the first roller 11 so as to rotate relative to the first roller 11. [46] The outer circumferential surface of the first roller 11 is provided with the plurality of pins 15. The number of pins 15 is about 30/inch , and the diameter of each of the pins 15 ranges from about 0.2 to 5 mm. More preferably, the diameter of each of the

pins 15 ranges from about 1 to 3 mm. Further, the length of each of the pins 15 is about 1 mm or more, and more preferably the length of each of the pins 15 is about 2 to 5 mm. Each pin 15 has a tip portion 15a at one end thereof, and apertures 16 are formed as the tip portions 15a of the pins 15 penetrate through the non-woven fabric.

[47] As shown in FIG. 2, the second roller 12 has grooves 12a into which the pins 15 are inserted. The inner diameter of the groove 12a is larger than the outer diameter of the pin 15, and the number of grooves 12a is equal to the number of pins 15.

[48] As shown in FIG. 3, the outer surface of each of the second rollers 12 may be provided with a brush, or may be made of an elastic material, such as rubber. The outer surface of the second roller 12 may be made of a porous material having a plurality of pores, such as a sponge gourd. That is, the outer surface of the second roller 12 receives portions of non- woven fabric which are pressed by the pins 15 of the first roller 11 when the non- woven fabric is penetrated by the pins 15 of the first roller 11, and than the surface state of the non- woven fabric is recovered.

[49] A method of perforating non- woven fabric according to a first embodiment includes a step of preparing one or more rolls of non- woven fabric Nl. The non- woven fabric Nl may be polypropylene (PP) spun-bond non- woven fabric, mixed non- woven fabric (SMS, SMMS, etc.) of polypropylene spun-bond and melt-blown non- woven fabric, bi-component spun-bond non- woven fabric, which is a mixture of polypropylene and polyethylene, spun-laced non- woven fabric, air-through processed non- woven fabric, polypropylene thermal-bond non- woven fabric, thermal-bond non- woven fabric of a mixture of polypropylene and other yarn, polyester non- woven fabric, etc.

[50] The prepared non- woven fabric Nl is passed through between the first roller 11 and the second rollers 12. As a result, as shown in FIGs. 2 and 3, the pins 15 of the first roller 11 penetrate through the surface of each roll of the non- woven fabric, and thus perforated non- woven fabric N2 having a plurality of apertures 16 is produced.

[51] In this manner, according to the first embodiment, since a plurality of second rollers

12 is arranged on the outer circumferential surface of the first roller 11, a plurality of rolls of non- woven fabric N2 is perforated, and thus the perforated non- woven fabric N2 can be rapidly and accurately formed.

[52] FIG. 4 shows a method of perforating non- woven fabric according to a second embodiment of the invention.

[53] As shown in the figures, the method of perforating non- woven fabric according to the second embodiment may include a step of preparing a single roll of non- woven fabric Nl, and a step of sequentially allowing the single roll of non- woven fabric Nl to pass through gaps between the first roller 11 and the second rollers 12, so that the single roll of non- woven fabric Nl is repeatedly perforated through a plurality of steps and the non- woven fabric Nl may have the plurality of apertures 16.

[54] According to the second embodiment, a single roll of non-woven fabric Nl is repeatedly perforated with many apertures 16 through a plurality of steps. Accordingly, the size and apparent precision of the apertures 16 of the non- woven fabric N2 are improved and the perforation may be rapidly performed.

[55] The other structures and relational operations are the same as in the first embodiment. Accordingly, like or similar elements are referred to with like reference numbers.

[56] FIG. 5 shows an apparatus for and a method of perforating non- woven fabric according to a third embodiment.

[57] As shown in the drawing, the apparatus for perforating non-woven fabric according to the third embodiment includes a first roller 11 having a plurality of pins 15, and two or more opposing roller groups 20, 30, and 40. Each of the opposing roller groups 20, 30, and 40 includes two or more second rollers 21, 22, 31, 32, 41, and 42.

[58] The method of perforating a non- woven fabric according to the second embodiment includes a step of preparing one or more rolls of non- woven fabric Nl, a steps of passing the respective rolls of non- woven fabric Nl through gaps between the first roller and the respective opposing roller groups 20, 30, and 40 while each roll of the non- woven fabrics sequentially passes through gaps between the first roller 11 and the respective second rollers 21, 22, 31, 32, 41, and 42. Accordingly, the plurality of rolls of non- woven fabric Nl is perforated two or more times by the two or more second rollers 21, 22, 31, 32, 41 and 42 of the two or more opposing roller groups 20, 30, and 40, so that the non- woven fabric N2 having a plurality of apertures 16 is produced.

[59] In the above-mentioned apparatus for and method of perforating non- woven fabric, the first roller 11 and the second rollers 21, 22, 31, 32, 41, and 42, operating in relation with the first roller 11, rotate at low speed in the range from 1 to 50 m/min. Accordingly, it is possible to rapidly and accurately perforate non- woven fabric, and thus the productivity and cost efficiency of the perforated non- woven fabric are improved.

[60] As the rotation speed of the rollers decreases, the quality of the perforated non- woven fabric becomes higher.

[61] When perforating, as the perforation is performed at lower speed, preferably in the range from 1 to 20 m/min, the apertures formed in the non-woven fabric become more precise and the appearance of the perforated apertures of the non- woven fabric improves.

[62] FIG. 6 shows the non- woven fabric N2 having a plurality of apertures 16, which is produced using the above-mentioned apparatus for and method of perforating non- woven fabric. Peripherals of the perforated apertures 16 come to protrude by being pressed by the pins 15 of the first roller 11 and the second rollers 12, so that the cushiony property is imparted to the non- woven fabric N2. The shapes of the apertures

16 and the peripherals of the perforated non-woven fabric vary according to the kind of non-woven fabric, the operation line speed, and the temperature of the first and second rollers.

[63] The total area of the apertures 16 becomes 1 to 50% of the entire surface area of the perforated non- woven fabric N2, and the number of apertures 16 may be preferably 30/inch or more. Perforated shape of FIG. 6. can changed to various shape by pin temerature, pin pressure, nonwoven type, nonwoven thickness and perforating line speed.

[64] The perforated non- woven fabric produced by employing the above-mentioned apparatus for and method of perforating a non- woven fabric may be used in the state of being in direct contact with or attached to a part of a human body, used as a lining of a sanitary napkin or a diaper, as a cleaning cloth, or for the agricultural use.

[65] (Embodiment 1)

[66] A roll of bi-component spun-bond non- woven fabric which is a mixture of polypropylene and polyethylene (manufactured by Toraysaehan Co. Ltd.) of 20 g/m is sequentially perforated at the speed of 6 m/min two times, as shown in FIG. 5. At this time, the temperature of the first roller 11, and the temperature of the second rollers 21, 22, 31, and 32, which are rollers opposing the first roller 11, is 105 ⁰ C.

[67] Each of the second rollers has the same number of grooves as the number of pins.

[68] The diameter of the pin is about 1.9 mm, and the number of pins is about 63/inch .

[69] Four second rollers are used, two rolls of non- woven fabric are used, and each of the non- woven fabrics is perforated at a speed of 6 m/min.

[70] (Embodiment 2)

[71] With the exception that four rolls of non- woven fabric are used, the embodiment 2 is the same as the embodiment 1.

[72] (Embodiment 3)

[73] The non- woven fabric in the first embodiment is used as a lining of a diaper. The diameter is manufactured by Suan Industrial Co., Ltd.

[74] (Embodiment 4)

[75] The non- woven fabric in the first embodiment is used as a cleaning cloth for wiping a window of an automobile.

[76] (Embodiment 5)

[77] The non- woven fabric in the first embodiment is used in washing hands with soap.

[78] (Test result)

[79] According to the embodiment 1, each of two rolls of non- woven fabric is perforated at a speed of 6 m/min. Accordingly, the total operation speed is 12 m/min.

[80] According to the embodiment 2, each of four rolls of non- woven fabric is perforated at 6 m/min, and four rolls of the non- woven fabric are simultaneously perforated. Ac-

cordingly, the total operation speed is 24 m/min.

[81] In such a way, it is possible to improve the productivity of one perforating pin, which is expensive. Further, it is possible to improve work efficiency, work space efficiency, and quality of the perforated non- woven fabric by working at a low speed.

[82] According to the embodiment 3, the perforated non-woven fabric has the same feeling as the appearance of a diaper. When the diaper to which the perforated non- woven fabric according to embodiment 3 is tested with customers, feeling, hygroscopic property, and appearance are satisfactory to the customers.

[83] As the test result of the non- woven fabric according to the embodiment 4, that is, wh en the non- woven fabric is used as a cleaning cloth for an automobile window, it showed good washability.

[84] As the test result of the non- woven fabric according to the embodiment 5, washability was excellent, and the feeling was smooth, soft, and dry.

[85] The invention, which is described above, is not limited to the embodiments and the accompanying drawings, but it will be obvious that it can be diversely modified and changed within the scope of the invention by people ordinarily skilled in the art as long as does not deviate from the technical spirit of the invention. Accordingly, such modifications, alterations, and changes fall within the scope of the claims of the invention.