JP2000045161A - Nonwoven opening fabric and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a nonwoven opening fabric having functionality to various uses such as the surface sheets absorbing articles, medical materials such as gauze, table cloth, wet tissue, dish cloth, wiping materials such as wiper or the like, having a characteristic opening pattern excellent in design. SOLUTION: Fiber web is loaded on an opening forming support, and is confounded and rearranged by injecting striated high pressure fluid, to obtain the objective nonwoven opening fabric having alternately existing non opening lines 3 and lines 2 of continuously connected openings 4 passing through from the surface to the back, by forming continuous openings of at least n lines and n+1 lines on the opening line 2 when assuming the number of lines as (n) ((n) is an integer of 1 to 4).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nonwoven fabric having a unique opening pattern,
The present invention relates to an apertured nonwoven fabric which is useful for medical materials such as gauze, tablecloths and the like, and is particularly suitable for wiping materials such as precision wipers, cleaning wipers, wet wipers, wet tissues, and towels, and a method for producing the same.

[0002]

2. Description of the Related Art Various perforated nonwoven fabrics have been proposed and put into practical use. In particular, a nonwoven fabric having a unique opening pattern in which apertures and non-openings exist in a row has been proposed in order to obtain functionality and design according to the use of the nonwoven fabric. For example, Japanese Unexamined Patent Publication (Kokai) No. 61-6355 proposes a nonwoven fabric having an opening pattern at a constant repetition interval. JP-A-1-321961 proposes a lattice-pattern apertured nonwoven fabric in which aperture rows are formed in the longitudinal direction and width direction of the nonwoven fabric, and JP-A-4-82948 discloses at least two lines. A nonwoven fabric has been disclosed in which an aperture row is formed in which apertures are in contact with each other and are arranged side by side.

[0003]

However, these perforated nonwoven fabrics have the following problems. When these nonwoven fabrics are used as wiping materials such as wet tissues and wipers, small contaminants are trapped in the non-opening portions, and relatively large contaminants are selectively trapped in the opening portions, but the thickness of the nonwoven fabric is thin. Then, the filth passes through the opening and soils the hands and the like.

[0004] Therefore, the fact is that a nonwoven fabric having a unique opening pattern having both functionality and designability according to the use of the nonwoven fabric has not been obtained. The present invention has been made in view of such circumstances, and has functionality for various uses such as surface materials of absorbent articles, medical materials such as gauze, wet tissues, towels, wipers and other wiping materials. Another object of the present invention is to provide a nonwoven fabric having a unique opening pattern excellent in designability.

[0005]

The perforated nonwoven fabric of the present invention comprises:
In the nonwoven fabric in which the fibrous webs are entangled by the action of the high-pressure fluid flow and the fibrous webs are rearranged to form openings that penetrate from the front surface to the back surface, open rows and non-open rows are alternately present, Further, when the number of rows is n (n = 1 to 4), the aperture row is formed by mixing n rows and n + 1 rows or more continuous apertures.
By adopting such a configuration, a nonwoven fabric having functionality for various uses and having a unique opening pattern excellent in design can be obtained.

In the aperture row of the apertured nonwoven fabric according to the present invention, it is desirable that one row of continuous apertures and two or more rows of continuous apertures coexist. In addition, in the opening row, it is desirable that one row of continuous openings and two rows of continuous openings are mixed. Further, in the opening row, it is desirable that two rows of continuous openings are arranged in a staggered manner.

The width of the non-perforated row in the perforated nonwoven fabric of the present invention is desirably 3 to 15 mm.

The fibrous web in the perforated nonwoven fabric of the present invention desirably contains at least 30% by weight of hydrophilic fibers. Use of such fibers is suitable for wet wipes such as wet wipers, wet tissues, and disposable towels.

The fibrous web in the perforated nonwoven fabric of the present invention is made of an incompatible two-component resin, and contains at least 50% by weight of a splittable conjugate fiber in which at least one component is divided into two or more in a fiber cross section. It is desirable to do. Use of such fibers is suitable for high-performance wiping materials such as wipers for OA equipment and precision wipers.

In the perforated nonwoven fabric of the present invention, a fibrous web is placed on a support for forming perforations, and a high-pressure fluid stream is jetted in a streak shape to entangle the fibers and simultaneously rearrange the fibers. Opening rows and non-opening rows alternately exist, and the number of rows is n (n = 1 to 1).
(An integer of 4) can be manufactured by forming continuous rows of n rows and n + 1 rows or more in the row of apertures. Hereinafter, the contents of the present invention will be specifically described.

[0011]

FIG. 1 shows an example of a preferred embodiment of a perforated nonwoven fabric according to the present invention. 1 is an apertured nonwoven fabric of the present invention, 2 is an aperture row, 3 is a non-open row, and 4 is an aperture. The perforated nonwoven fabric of the present invention is a nonwoven fabric in which the fibrous web is entangled by the action of a high-pressure fluid flow and the fibrous web is rearranged to form an aperture that penetrates from the front surface to the back surface.
At least three continuous holes in the longitudinal direction (hereinafter referred to as
Row (hereinafter referred to as an open row) and a row having substantially no openings (hereinafter referred to as a non-open row).
Are alternately arranged in parallel, and the aperture row is formed by mixing n rows and n + 1 rows or more of continuous apertures.
For example, if the number of columns is n = 1, the embodiment shown in FIG. 1 is shown.

The fibrous web used for the perforated nonwoven fabric of the present invention is not particularly limited. For example, natural fibers such as cotton and silk, regenerated fibers such as rayon, semi-synthetic fibers such as acetate, acrylic fibers, nylon 6. Polyamide fibers such as nylon 66, polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, and polyolefin fibers such as polyethylene and polypropylene. Can be. In addition, the fiber shape and the like are not particularly limited, and a single fiber, a sheath-core type composite fiber, a split type composite fiber, a fiber having an irregular cross section, or the like can be arbitrarily used.

For example, when the finally obtained nonwoven fabric is used as a dry wiping material such as a flooring wiper or a precision wiper for wiping fine dust and dirt, the fineness is not more than 3.5 dtex. Consisting of two incompatible components composed of a combination of synthetic fibers, nylon / polyester, polyester / polypropylene, ethylene-vinyl alcohol copolymer / polypropylene, polyester / polyethylene, etc., and at least one component is divided into two or more in the fiber cross section The resulting splittable conjugate fiber is preferably contained in an amount of 50% by weight or more, more preferably 70% by weight or more. As the fiber to be mixed with the splittable conjugate fiber, for example, a polyester fiber or a rayon fiber having a fineness of 2.2 dtex or less may be mixed.

When used as a wet wiping material such as a wet wiper, a wet tissue, or a disposable towel, natural fibers such as cotton and silk, recycled fibers such as rayon, semi-synthetic fibers such as acetate, and acrylic-based fibers It is preferable to contain 30% by weight or more, more preferably 50% by weight or more of hydrophilic fibers such as fibers. Further, the use of hydrophilic fibers is also advantageous in that clear openings are easily formed.

The form of the fibrous web made of the fibers is not particularly limited, and a parallel web or cross web made of staple fibers, a semi-random web, a long fiber web made of continuous filaments, a web obtained by wet-making short fibers,
Alternatively, a melt-blown nonwoven fabric or the like can be used arbitrarily, but among them, the use of a fibrous web made of staple fibers is preferred because the fibers can be entangled firmly. The fibrous web is not limited to a single layer, and may be a laminate in which two or more fiber layers of different materials are laminated. For example, if a pulp layer such as a tissue is inserted between two fiber webs, the fibers can be easily entangled with each other and a clear opening can be formed, which is convenient.

The obtained fibrous web is placed on a support for forming pores, and a high-pressure fluid flow is jetted in a streak form.
The fibers are rearranged at the same time as the fibers are entangled. The “fluid” used in the present invention is not limited as long as the fibers can be entangled with each other and the fibers can be rearranged. However, water is particularly desirable in terms of process control. Injection of the high pressure fluid stream is performed under conditions such that the fibers of the web are rearranged to form apertures in the nonwoven. Specifically, the fibrous web is placed on a support for forming openings, and a high-pressure fluid flow is jetted onto the fibrous web. The form of the support for forming the openings is not particularly limited, and a commonly used one such as a pattern net formed by weaving a monofilament or a metal wire or a roll provided with protrusions can be used arbitrarily. At this time, the interval between the aperture forming portions in the aperture forming support,
It is preferably 1 to 5 mm.

The injection of the high-pressure fluid flow may be performed only on the support for forming the holes, or after the liquid is preliminarily entangled with a low-pressure fluid flow, the fluid may be sprayed on the support for forming the holes. A stream may be injected. Preliminary entanglement increases the strength of the resulting nonwoven. It is necessary to set the pressure of the fluid flow to be sprayed on the support for forming the openings in accordance with the basis weight of the web to be processed and the presence or absence of pre-entanglement. For example, when processing a web of 20 to 100 g / m2, a nozzle in which one or two or more orifices having a hole diameter of 0.05 to 0.5 mm are arranged at equal intervals in a direction (width direction) orthogonal to the machine direction is inserted in the machine direction. (Longitudinal direction) Use one or more, and the pressure of the fluid flow is 15-100 kg / c
It is preferable to treat with m2. Nozzle hole diameter is 0.05
If it is less than 0.5 mm, it is difficult to obtain clear apertures, and if it exceeds 0.5 mm, the formation of aperture rows becomes poor. If the pressure of the fluid flow is less than 15 kg / cm 2, the energy of the fluid flow is insufficient and it is difficult to form an opening. If it exceeds 100 kg / cm2, the fibers may be scattered and the formation may deteriorate, and the support may be damaged depending on the material and shape of the support. When performing preliminary confounding, the web may be placed on a permeable support, and a fluid flow of 20 to 60 kg / cm 2 may be jetted.

Further, the interval between the injections of the fluid in the high-pressure fluid flow is preferably 3 to 15 mm. The width of the non-perforated row can be adjusted to 3 to 15 mm by adjusting the ejection interval of the fluid. If the injection interval is less than 3 mm, holes are formed substantially on the entire surface, and if it exceeds 15 mm, the number of holes becomes extremely small.

The shape, pattern, and area per hole of the nonwoven fabric are determined by the form of the support for forming holes. The shape of the aperture in the present invention is not particularly limited, and may be any of a circle, an ellipse, a rectangle, a rhombus, and the like. Considered a hole. On the other hand, the opening pattern is not particularly limited, either, and may be a lattice shape, a staggered shape, or the like. In addition, the area per one hole is 0.1 mm.
Desirably, it is 1 to 5 mm2. More preferably,
0.2 to 2 mm2. If the opening area is less than 0.1 mm2, the effect of the opening cannot be sufficiently obtained. If the opening area exceeds 5 mm2, the difference between the space between the opening row and the non-opening row is too large. This is because, in the case of using, the waste comes through through the opening, the contact area with the object becomes small, and the unwiped residue increases.

For example, in order to obtain a nonwoven fabric having a mixture of one row of continuous openings and two rows of continuous openings, a nozzle in which orifices are arranged one at a time in the width direction at equal intervals is used. When two or more holes are installed and water flow is sprayed, a large hole with a hole area of 0.5 mm2 or more and a small hole of less than 0.5 mm2 are formed in one row as a continuous hole, and the size of the hole is Some continuous apertures are formed in a state of being substantially aligned in two rows. Although the reason is not clear, when the second water stream collides with the opening that was opened by the first jet of water, it partially buffered and partially formed a larger opening,
It is presumed that the opening is closed in another part and rearranged into a small opening. When two rows of continuous openings are arranged in a zigzag pattern, it can be easily obtained by using a pattern net having knuckles or projections arranged in a zigzag pattern as a support for forming the openings.

The obtained apertured nonwoven fabric has aperture rows and non-open rows alternately, aperture rows and non-open rows alternate, and the number of rows is n (n = 1 to 1). (An integer of 4), the aperture row is formed by mixing continuous rows of n rows and n + 1 rows or more. The number n of rows may be appropriately set according to the use of the nonwoven fabric. For example, in the case of a medical material such as a surface sheet of an absorbent article, gauze, etc., when n = 3 to 4, in terms of liquid permeability and air permeability, Advantageously, for wiping materials n =
When it is set to 1 to 3, it is advantageous in terms of collecting waste. When the number of rows is n> 4, there is no significant difference in functionality and design between the conventional nonwoven fabric having openings formed on the entire surface. For example, when used as a wiping material, capture small dirt in a non-perforated row,
Relatively large dirt is selectively trapped in the aperture row. At this time, the continuous openings of n rows and n + 1 rows or more mixed in the opening row selectively capture even relatively large dirt. In addition, it is preferable that the size of the openings be different in size, because the selective capturing property is improved. In particular,
In the aperture row, a nonwoven fabric in which one row of continuous apertures and two rows of continuous apertures are mixed is preferable in that dirt of any size can be efficiently captured.

Further, in the above-mentioned hole array, it is preferable that two continuous holes are arranged in a staggered manner. By arranging in a staggered manner, in the wiping direction, dirt that has passed without being collected in the continuous opening in the front row of the two rows can be collected in the continuous opening in the rear row, so that the initial wiping property is high. .

Further, the width of the non-perforated row in the perforated nonwoven fabric of the present invention depends on the ejection interval of the fluid in the high-pressure fluid flow,
Preferably it is 3 to 15 mm. More preferably, 5
10 mm. The width of the non-opening row referred to here is the maximum width of the opening row, where the largest distance between the openings in the direction orthogonal to the continuous continuous opening in the longitudinal direction is the maximum width of the opening row. It refers to the length from the center line of the maximum width to the center line of the width of the adjacent aperture row. If the width of the non-perforated row is less than 3 mm, it is inferior to the conventional non-perforated nonwoven fabric in which perforations are regularly formed, and poor in collecting small dirt. On the other hand, if it exceeds 15 mm, it is not possible to obtain a trapping effect by the row of apertures.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described with reference to embodiments. The thickness, tensile strength, elongation at break, and collection rate of the obtained nonwoven fabric were measured as follows.

[Thickness] Thickness measuring device (trade name: THICKNESS)
GAUGE model CR-60A manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.)
The measurement was carried out with a load of 20 g applied per cm 2 of the sample.

[Tensile strength, elongation at break] JIS L10
According to 96, a sample piece having a width of 5 cm and a length of 15 cm is gripped at a spacing of 10 cm, and is stretched at a tensile speed of 30 cm / min using a constant-speed stretching type tensile tester. Tensile strength and breaking elongation were used.

[Collection rate] (1) Dry non-woven fabric A heat-resistant lubricating paste (Dow Corning
1 g of Asian brand (Moricoat) is evenly applied, and the weight of the nonwoven fabric is measured after reciprocating once with a load of 100 g applied on a 3 cm x 3 cm nonwoven fabric whose weight has been measured in advance. 100 divided by the weight of
The doubled value was defined as the collection rate. (2) Wet non-woven fabric 0.5 g of 7 kinds of JIS dust on a glass surface at 10 cm × 30
A non-woven fabric of 7 cm × 10 cm adjusted to a water content of 150%, whose weight was measured in advance, was attached to a sponge of 7 cm × 10 cm, and a weight of 500 g was applied. The weight of the nonwoven fabric after wiping was measured, and the value obtained by multiplying 100 times the value obtained by dividing by the original weight was defined as the collection rate.

[Example 1] A splittable conjugate fiber (fineness: 2.2 dtex, fiber length: 51 mm) having a cross-sectional shape and divided into eight radially divided sections in which the first component is polyethylene terephthalate and the second component is high-density polyethylene. 40g / m2 using
A card web is prepared, the card web is placed on a normal support of 100 mesh, and using a nozzle having orifices having a hole diameter of 0.12 mm provided at 0.6 mm intervals,
After injecting a columnar water stream with a water pressure of 50 kg / cm2, the hole diameter was 0.15.
Using a nozzle having 5 mm orifices at intervals of 5 mm, a columnar water stream having a water pressure of 100 kg / cm2 is jetted twice on a support for forming an opening (a plain fabric manufactured by Nippon Filcon Co., Ltd., 25 mesh). And dried at 100 ° C. to obtain a dry nonwoven fabric with open pores. In the obtained nonwoven fabric, one row of continuous apertures and two rows of continuous apertures were mixed, and the two rows of continuous apertures were arranged in a staggered manner.

Example 2 Fineness 1.65 dtex, fiber length 4
Eccentric sheath-core composite fiber (CPP, manufactured by Daiwa Spinning Co., Ltd.) 30 comprising 70% by weight of 0 mm rayon fiber, a fineness of 2.2 dtex, and a sheath length of 51 mm, made of an ethylene-propylene copolymer and a polypropylene core. An opening was formed in the same manner as in Example 1, except that a card web of weight% was used.
Heat treatment was performed with a hot air dryer at 130 ° C., and the eccentric sheath-core conjugate fiber was spirally expressed to obtain an apertured nonwoven fabric. In the obtained nonwoven fabric, as in Example 1, one row of continuous apertures and two rows of continuous apertures were mixed, and the two rows of continuous apertures were arranged in a staggered manner. Then, a moisture content of 1
Water was immersed so as to be 50% to form a wet-shaped open nonwoven fabric.

Comparative Example 1 Using the splittable conjugate fiber of Example 1, a card web of 40 g / m 2 was prepared, and the card web was placed on a 100-mesh ordinary support having a hole diameter of 0.12 mm. Using a nozzle provided with orifices at intervals of 0.6 mm, a columnar water stream having a water pressure of 50 kg / cm 2 was jetted, and dried at 100 ° C. to obtain a dry nonwoven fabric. The obtained nonwoven fabric was a flat nonwoven fabric having no openings.

Comparative Example 2 A nonwoven fabric was obtained in the same manner as in Comparative Example 1 except that the card web of Example 2 was used. The obtained nonwoven fabric was a flat nonwoven fabric having no openings. Then, the obtained nonwoven fabric has a moisture content of 150%.
% Of water to form a wet nonwoven fabric.

[Comparative Example 3] A comparative example was adopted except that the support for forming the holes of Example 1 (plain woven fabric manufactured by Nippon Filcon Co., Ltd., 25 mesh) was used as the support of the card web of Example 2. An apertured nonwoven fabric was obtained in the same manner as in Example 1. The obtained nonwoven fabric had zigzag openings on the entire surface. Then, water was immersed in the obtained perforated nonwoven fabric so as to have a moisture content of 150% to obtain a wet perforated nonwoven fabric. Example 1
Table 1 shows the physical properties of Comparative Examples 1 to 3 and Comparative Examples 1 to 3.

[0033]

[Table 1]

Since the apertured nonwoven fabrics of Examples 1 and 2 were formed with apertures at appropriate intervals, a wide range of small dusts to sticky substances could be captured in both the dry state and the wet state. . In Comparative Examples 1 and 2,
Since no openings were formed, it was difficult for dirt to enter the fiber entangled portion, and the collection property was insufficient. In Comparative Example 3, the filth penetrated strongly, and the filth considerably adhered to the sponge of the jig.

[0035]

The apertured nonwoven fabric of the present invention has aperture rows and non-open rows alternately, and the aperture row is formed by mixing n rows and n + 1 or more continuous apertures. Therefore, a nonwoven fabric having functionality for various uses and excellent design properties, and having a unique opening pattern which has not existed conventionally can be obtained. In particular, in an aperture row, a nonwoven fabric in which one row of continuous apertures and two rows of continuous apertures are mixed can efficiently capture dirt of any size when used as a wiping material.

The perforated nonwoven fabric of the present invention is also useful for surface sheets of absorbent articles, medical materials such as gauze, tablecloths, etc., and particularly wipes such as precision wipers, cleaning wipers, wet wipers, and towels. 30% hydrophilic fiber in the nonwoven fabric of the present invention.
It is suitable for a wet wiper such as a wet wiper, a wet tissue, a disposable towel, etc. by containing it by weight. In addition, the open nonwoven fabric of the present invention contains at least 50% by weight of a splittable conjugate fiber composed of an incompatible two-component resin and having at least one component divided into two or more in the cross section of the fiber. It is suitable for high-performance wiping materials such as equipment wipers and precision wipers.

[Brief description of the drawings]

FIG. 1 shows an example of the surface of a perforated nonwoven fabric of the present invention.

[Explanation of symbols]

 1. Perforated nonwoven fabric 2. 2. Aperture row Non-perforated row Opening

Claims (8)

[Claims] 1. A nonwoven fabric in which a fibrous web is entangled by the action of a high-pressure fluid flow and the fibrous web is rearranged to form an opening penetrating from the front surface to the back surface, wherein an opening row and a non-opening row are alternately arranged. Exists and the number of columns is n
An apertured nonwoven fabric characterized in that, when (n = 1 to an integer of 1 to 4), the aperture row is formed by mixing n rows and n + 1 rows or more continuous apertures. 2. The perforated nonwoven fabric according to claim 1, wherein in the perforated row, one row of continuous perforations and two or more rows of continuous perforations are mixed. 3. An aperture row, wherein one row of continuous apertures and two rows of continuous apertures are mixed.
Or the nonwoven fabric having pores according to 2. 4. The apertured nonwoven fabric according to claim 1, wherein in the aperture row, two rows of continuous apertures are arranged in a staggered manner. 5. The open nonwoven fabric according to claim 1, wherein the width of the non-opening rows is 3 to 15 mm. 6. The perforated nonwoven fabric according to claim 1, wherein the fibrous web contains hydrophilic fibers in an amount of 30% by weight or more. 7. The fibrous web is made of an incompatible two-component resin, and contains at least 50% by weight of a splittable conjugate fiber in which at least one component is split into two or more in a fiber cross section. The perforated nonwoven fabric according to any one of claims 1 to 5. 8. A fiber web is placed on a support for forming holes, and a high-pressure fluid stream is jetted in a streak shape to entangle the fiber web and to rearrange the fiber web so that the fiber web is not opened. And a row of holes, wherein the number of rows is alternate and the number of rows is n (n is an integer of 1 to 4). Manufacturing method of nonwoven fabric.