JPH0482948A - Patterned nonwoven fabric and production thereof - Google Patents

Abstract

PURPOSE:To provide the title product useful as a surface sheet for sanitary napkins capable of taking full advantage of their liquid absorptivity using a special opening support, with such appearance that openings in two or more rows come into mutual contact and appear as if in a row. CONSTITUTION:Firstly, using an opening support 15 consisting of plain weave texture comprising lineal materials with the diameter ratio of the longitudinal lineal material 21 to crosswise one 22 being (1:5)-(1:10) in which the longitudinal lineal materials 21 are comprised of (1) those 21A, 21B in mutual contact in the width direction and (2) those 21A, 21A or 21B, 21B in mutual separation in the width direction, a fibrous web is supported on said support 15. Thence, a highly pressurized fluid is ejected on said fibrous web to interlace the constituent fibers of said web, thus obtaining the objective product 1.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a nonwoven fabric made by intertwining fibers with each other, and a method for producing the same. The present invention relates to a nonwoven fabric obtained by interlacing and patterning, and a method for manufacturing the same.

(Prior art) Conventionally, non-woven fabrics with patterns have been made up of circular or elliptical openings, and the size and size of the openings have been determined.
Nonwoven fabrics are known that have substantially the same shape and are regularly arranged to form a pattern. One of the manufacturing methods for this nonwoven fabric is to use a mesh screen as a support in which knuckles where constituent wires intersect are regularly arranged, and to inject a high-pressure water stream toward the fibrous web guided onto the support. A method is known in which fibers are intertwined and rearranged to simultaneously form an aperture pattern corresponding to the arrangement of the knuckles. In this case, the mesh screen generally has a plain weave structure composed of wire rods having approximately the same diameter in warp and weft. Details of such technology can be found in, for example, U.S. Pat.
It is disclosed by Publication No. 9.

(Problems to be Solved by the Invention) The apertures in the nonwoven fabric obtained by the two series of prior art techniques are usually arranged in a diamond pattern. This type of nonwoven fabric can be used as a liquid-permeable top sheet for sanitary napkins. When used in this manner, body fluids in the top sheet permeate through the openings into the absorbent body that is in contact with the inside of the top sheet and are absorbed therein. Sanitary napkins are made vertically for ease of use, but since the holes are generally evenly distributed across the entire surface sheet, the amount of liquid absorbed by sanitary napkins quickly reaches its limit in the narrow width direction. When the liquid reaches the end, it must be discarded, wasting the portion that still has room for liquid absorption in the vertical direction.

An object of the present invention is to provide a nonwoven fabric having an aperture pattern in which at least two apertures are arranged in contact with each other, as if the apertures are in a row of -stripes, and a method for producing the same. The disadvantages of the prior art described above can be overcome by using a sanitary napkin in which the row of openings coincides with the longitudinal direction of the sanitary napkin.

(Means for Solving the Problems) In order to solve the above problems, the gist of the configuration of the present invention is as follows.

A method for producing a patterned nonwoven fabric by jetting a high-pressure fluid onto a fibrous web supported on an apertured support to entangle the fibers of the web with each other, wherein the support is composed of a plain weave structure consisting of wires. Yes, the wire diameter ratio of the warp and weft of the structure is 1=5 or 1:
10, the edge wires are made up of wires that are in contact with each other in the width direction and wires that are spaced apart from each other.

Furthermore, the gist of the present invention is also the nonwoven fabric obtained by the above structure.

(Operations and Effects) In the manufacturing method configured as described above, one support has a plain weave structure as a whole, but by increasing the difference in wire diameter between warp and weft, only the warp wire with a small diameter is bent. Then, it repeatedly floats and sinks against the large-diameter latitude wire,
Openings are formed in the nonwoven fabric by the floating knuckles.

At that time, the small diameter longitude wire floats vertically on the large diameter longitude wire, and the shape of the opening in the nonwoven fabric formed there becomes an ellipse. When the warp wires are in contact with each other in the width direction, the oval holes in the nonwoven fabric also touch each other at both ends of the oval, as if they were a row of -strip holes. (corresponding to claim 1.2).

Can the nonwoven fabric obtained as described above be used as a top sheet for sanitary napkins? In particular, if the rows of holes are aligned in the vertical direction of the sanitary napkin, the liquid absorption capacity of the sanitary napkin can be used without wasting it. can be used. (Corresponding to claim 2).

(Embodiments) Next, embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view schematically showing the main parts of an apparatus for obtaining a nonwoven fabric 1 according to the present invention. In the figure,
A water film is supplied from a tank 12 to a fibrous material layer, preferably a fiber web 11 made of card, in which the fibers can move under the jet action of a high-pressure water jet, and after the fiber feathers are suppressed and the form is stabilized, holes are opened. Endless as support 15
The water is guided to a belt-shaped mesh screen, and a suction 16 is applied from below the mesh to drain water, while a high-pressure water stream is injected laterally from above the mesh from nozzles 17 having a predetermined diameter and pitch.

By this spraying treatment, the fibers on the support body 15 are rearranged in accordance with the mesh shape and intertwined with each other, resulting in the nonwoven fabric 1 having openings 2 formed in the knuckle portion 20, which will be described later. The nonwoven fabric 1 that has undergone opening and fiber entanglement is squeezed out of moisture by a pair of squeezing rolls 18, and then transferred to the next drying and winding process.

2A and 2B show a perspective view and a plan view of the support 15. FIG. The support 15 in the form of an endless belt is a plain weave mesh screen made of stainless steel wire and has warp wires 2J and weft wires 22. The weft wire rod 22 has a plurality of diameter wire rods arranged at equal intervals, and the warp wire rod 2] is a wire rod 21. whose ups and downs are opposite to each other with respect to the weft wire rods 22. The wire rods 21A and 2113 have the same wire diameter d, and the wire diameter d is 115 to 1/10 of the wire diameter. Because of the difference in diameter, in the support 15, the weft wire rods 22 are rigid and extend in the weft direction almost in a straight line, and the warp and warp wire rods 21 are rigid.
It extends in the longitudinal direction while repeating the bending of floating and sinking with respect to 2 (see Fig. 3, which will be described later). In the warp wire rod 21, a pair of wire rods 21A and 21B that are adjacent to each other are
Two adjacent wire rods 22 are substantially in contact with each other to form a contact region 25. Moreover, the wire rods 21A and 21A and 21B and 21B that are adjacent to each other are separated by a pitch Q. A region 24 surrounded by the warp wire rods 21A and 21B and the adjacent weft wire rod 22 (see FIG. 2B) is an opening in the open-hole support 15, and functions as a drainage hole,
The water after the injection is drained under the action of the suction 16.

FIG. 3 is a sectional view taken along line m-m in FIG. 2B, and is a sectional view of the web 1
1 schematically shows a state in which an opening 2 is formed. In the figure, the knuckle portion 23 is where the warp wire 21A is floating relative to the weft wire 22.

The constituent fibers (not shown) of the web 11 that were initially on the knuckle portion 23 are moved by the action of the jet water, and
3, and apertures 2 are formed in the web 11 (see FIG. 4, which will be described later).

FIG. 4 is a perspective view showing the state in which the web 11 has completed the openings and fiber entanglement and has become the nonwoven fabric 1. A plurality of oval openings 2 are formed in the nonwoven fabric 1 to follow the shape of the knuckle portions 23 of the warp wires 21A and 21B. Opening hole 2 is wire rod 21A
It has an aperture 2A that follows the shape of the wire rod 21, and an aperture 2B that follows the wire rods 21 and B, and a pair of adjacent apertures 2A and 2B touch each other at the end of an ellipse, as if forming a -strip aperture. They are lined up like this.

FIG. 5 is a partially cutaway perspective view showing a state in which the nonwoven fabric 1 of FIG. 4 is used as a top sheet 31 of a sanitary napkin 30. The sanitary napkin 30 is made up of a liquid-permeable top sheet 31, a liquid-impermeable back sheet 32, and an absorbent body 33 interposed between them. Top sheet 3
The first row of openings 2 is aligned with the longitudinal direction of the sanitary napkin 30. The body fluid discharged onto the top surface of the top sheet 31 is quickly absorbed into the absorbent body 33 along the rows of apertures 2 in the vertical direction, but the apertures 2 are arranged intermittently in the horizontal direction, and the absorbent body Penetration into 33 is slow. Due to such a difference in absorption speed, body fluid can be absorbed in the longitudinal direction of the absorbent body 33 without waste, and can also be absorbed in the horizontal direction.

In the nonwoven fabric 1, the main conditions for making the openings 2A and 2B contact each other as if forming a row of openings in -stripes are that the mesh screen of the support 15 is The diameter of each wire is 0.05 to 0.4 mm,
and 0.25 to 2ITIn, and the wire diameter ratio of warp and latitude is in the range of 1 = 5 to 1:10, 25.4 m
It is practically effective to set the number of wire rods driven per meter to 10 to 150 wire rods for warp and 10 to 50 wire rods for wire rod. Further, the constituent fibers of the web 11 are those commonly used in the past for nonwoven fabrics and woven fabrics, and
Fiber length and denier are 20 to 100,100 respectively.
II, 0.5~], 5d is used. The basis weight of the nonwoven fabric 1 is generally 10 to 150 g/m.

The jetting condition of the same pressure jet water is preferably 15 kg/a+f or more.

In addition to the above, the rows of apertures 2 in the nonwoven fabric 1 can be arranged so that three or more warp wires are in contact with each other.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the main parts of the nonwoven fabric manufacturing process for carrying out the present invention, FIGS. 2A and 2B are a perspective view and a plan view of a perforated support, and FIG. 3 is a sectional view of the support. FIG. 4 is a perspective view of a nonwoven fabric according to the present invention, and FIG. 5 is a partially cutaway perspective view of a sanitary napkin using the same nonwoven fabric. 1... Nonwoven fabric 2. 2A, 2B... Opening 15... Opening support 21, 21A, 2], B... Warp wire 22... Weft wire 24... Opening, d...Diameter

Claims (2)

[Claims] (1) A method for producing a patterned nonwoven fabric by injecting high-pressure fluid onto a fibrous web supported on a perforated support and intertwining the fibers of the web with each other, wherein the support is made of a plain weave structure made of wire. The wire diameter ratio between the warp and weft of the structure is 1:5 to 1:10, and the wires of the warp are in contact with each other in the width direction, and the wires are spaced apart from each other. The method for producing the patterned nonwoven fabric, characterized in that it consists of a wire rod. (2) Claim 1 characterized in that at least two rows of apertures are arranged in contact with each other to form a row of apertures.
Patterned nonwoven fabric according to the method described.