JPH0433905B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a perforated nonwoven fabric and a method for producing the same, and more particularly to a perforated nonwoven fabric having a special perforated pattern and a method for producing the same. It is.

[Conventional technology]

The web is placed on an endless belt, a cylindrical wire mesh, or a perforated plate, and a water stream is applied to it while moving.The water stream moves the fibers that make up the web, and the holes in the wire mesh are removed. Japanese Patent Publication No. 36-7274 describes a method for producing perforated nonwoven fabric in which the fibers at intersections of wire mesh or unperforated parts are removed to form perforated parts.
It is disclosed in the publication No.

However, this method only provides a monotonous perforated pattern over the entire surface of the nonwoven fabric. Therefore, various attempts have been made to provide more complex lace patterns.

For example, the perforations of the plate (supporting plate) on which the above-mentioned web is to be deposited have a special pattern, and the holes have a lace-like pattern.
This is disclosed in Publication No. 18069, etc.

Further, Japanese Patent Publication No. 10666/1983 discloses that a composite pattern of large lace-like openings and small openings in the net-like material can be produced by combining a net-like material with the perforated portion of the support plate.

In addition, the distance between the perforations in the plate on which the web is to be deposited is made different from the distance between the water nozzles that generate rod-shaped water flows, and the pattern of the perforations is applied only to the areas where the nozzles and perforations coincide. Japanese Patent Application Laid-Open No. 61-6355 discloses a method of imparting a striped pattern in the longitudinal direction of the web, in which the portions that do not correspond to the perforations are made non-perforated and patternless.

In addition, it was proposed in 1973 that the water flow hitting the web be blocked by a shielding plate perforated in a special pattern to limit the opening area and to give the opening a shape and pattern.
This is disclosed in Publication No. 10666, etc.

[Problem to be solved by the invention]

The method disclosed in Japanese Patent Application Laid-open No. 61-6355 only produces monotonous vertical stripes in the longitudinal direction, and furthermore, in order to change the pattern, it is necessary to replace the nozzle and the support plate that receives the web each time. However, there are problems in that industrial implementation requires a lot of labor and furthermore, production is interrupted during replacement, resulting in losses.

Also, Special Publication No. 47-18069 and Special Publication No. 54-10666
The method of applying a pattern on a support plate with a pattern, such as the method disclosed in the above publication, requires replacing the support plate in order to change the opening pattern, and there are problems in industrial implementation similar to those mentioned above. Also, from the viewpoint of the strength and shape retention of the support plate, the openings in the support plate should be discontinuous and independent, and there are restrictions such as the width of the non-opening part needs to be at least a certain width. There are limits to the aperture patterns that can be obtained.

Similarly, the method disclosed in Japanese Patent Publication No. 54-10666, etc., in which water flow is blocked by a shielding plate with specific openings, alleviates the problem of replacing the support plate described above, but it also has limitations on the opening pattern of nonwoven fabrics. remains a problem.

In any of these methods, the boundary between the perforated part and the non-perforated part becomes clear, and as a nonwoven fabric that should be used as a substitute for textiles, it looks bad, and furthermore, it has a bad feel and texture. There was a problem that stress during deformation was concentrated in this part.

Another problem with these methods is that whether the aperture pattern is provided on the supporting plate or the shielding plate, the aperture shape of the aperture plate maintains the shape of the aperture plate. Therefore, it is necessary to make the opening independent, and it is difficult to make it minute in terms of machining accuracy and strength of the molded plate.
The openings had to be made larger, and only lace-like nonwoven fabrics with large openings could be obtained.

These lace-like, large-diameter openings are found in household goods such as wet wipers and industrial wipers, which have few non-opening surfaces that are effective in wiping away contaminated surfaces of nonwoven fabrics, and therefore lack the ability to wipe away dirt. ,
Because of the large opening, dirt may pass through the opening and stain hands, which is undesirable.

Therefore, the present invention has developed a novel material that has an excellent appearance, feel, and feel that can be used as a substitute for textiles, has an excellent function of wiping away dirt, and does not allow the dirt to pass through the nonwoven fabric and stain hands. The purpose of the present invention is to provide a structural nonwoven fabric and a method for producing the nonwoven fabric.

[Means to solve the problem]

The present inventors have discovered that a nonwoven fabric in which pores of around 1 mm or less are arranged in a lattice pattern so that the pores are regularly spaced between the non-porous areas and separate the non-porous areas in both the vertical and horizontal directions is the one that can provide a large wiping surface. In addition, it has excellent flexibility and unevenness due to the effect of the openings, and therefore has excellent wipeability, and we have reached the conclusion that it is effective in solving the above problems. As a result of research into methods of implementation, the present invention has been completed.

That is, the object of the present invention is to provide a nonwoven fabric having a perforated part and a non-perforated part, the perforated part having a diameter of 0.2 mm to 0.2 mm.
A hole with a size of 1.5 mm is about 1.2 mm in size.
Rows are formed in the longitudinal direction (longitudinal direction) and the width direction (horizontal direction) of the nonwoven fabric at intervals of twice to three times, and the rows of openings are formed in the vertical and horizontal directions, independently of the 2nd to 3rd row of the openings. This is achieved by a nonwoven fabric characterized in that every nine non-perforated portions are divided at approximately equal intervals and arranged to form a lattice pattern.

A preferred manufacturing method for producing the perforated nonwoven fabric is to place the web on a support net of 5 to 40 meshes, and apply a water stream from above the web over the entire width of the web to form the support net. In manufacturing a nonwoven fabric with openings by removing web constituent fibers from the wire, the mesh spacing of the support net installed between the web and the water source is 19/10 to 11/10 or 1
By blocking the water flow with a shielding net having meshes at intervals of 0/11 to 10/19, holes are drilled only at the points where the water flow passing through the openings of the shielding net overlaps with the convex portions of the wires of the support net. It is characterized by generating apertures with a regular lattice-like interference pattern.

To explain the perforation pattern, which is a feature of the present invention, with reference to the drawings, FIG. are arranged to form vertical rows 3 and horizontal rows 4 at equal intervals, and
An example of this is a grid pattern surrounding a portion 2 that is completely unperforated. The row of apertures forming the lattice may be one row, such as the horizontal row 4 in FIG. 1, or may be composed of a plurality of rows, such as two vertical rows 3.

It should be noted that the rows of holes may not be completely completed throughout the nonwoven fabric, and that the number of rows may change to an adjacent row midway or partially change, which is a problem in the present invention described later. It should be understood that this can naturally occur due to the manufacturing method. Moreover, this can be said to be a major difference from conventional perforated nonwoven fabrics using support plates or shielding plates with an aperture pattern.

In both the vertical and horizontal rows, the intervals between the rows should be approximately equal, with every 2 to 9 openings, more preferably every 4 to 7 openings, in the row orthogonal to the row. This is important in that it determines the size of the non-opening area or the ratio of the opening area to the non-opening area.
Here, the intervals between the vertical and horizontal columns may be set independently.

The size of the opening 1 (represented by the diameter in the case of a perfect circle, and the length of one side in the case of a square) must be approximately 1.5 mm or less, preferably 1.0 mm or less,
If it is larger than this, dirt will pass through the nonwoven fabric and stain hands when used as a wiper, similar to the conventional nonwoven fabric with a lace-like opening pattern. On the other hand, when the opening 1 is about 0.2 mm or less, the function of the opening becomes poor, which is not preferable.

The shape of the aperture does not need to be a perfect circle or square, but may be an ellipse or a rectangle, and in these cases, the size of the aperture 1 is expressed by the major axis or the length of the long side.

The interval between the apertures forming each row should be selected within a range of about 1.2 to 3 times the size of the apertures; anything outside this range is undesirable as it may impair the strength of the nonwoven fabric. Note that the aperture spacing in the vertical rows and the aperture spacing in the horizontal direction do not necessarily have to be the same, and may be independently selected within the above ranges.

The fibers forming the nonwoven fabric of the present invention are not particularly limited, and include synthetic fibers such as polyester, polyamide, polypropylene, and acrylonitrile polymers, recycled fibers such as rayon, Kirapura (copper ammonia method rayon), cotton, and other fibers. Any natural fiber may be selected arbitrarily, and it is also permissible to use two or more of them in combination, but from the viewpoint of functionality as a wiper, those consisting of or containing cellulose fibers are preferred. is often preferred.

These fibers may be short fibers, continuous fibers, or a mixture thereof.

The method for producing the web for producing the nonwoven fabric of the present invention is not particularly limited, and any conventionally known method can be used. That is, a method of suspending short fibers in water and making paper, a method of dispersing short fibers with an air stream and collecting them on a net, a method of forming staple fibers into a web using cards,
This is the so-called spunbond method, which is directly connected to spinning to form a web.

In order to process these webs into the perforated nonwoven fabric with the special pattern of the present invention, 5 to 40 meshes,
More preferably, the web is placed on a net with 8 to 30 meshes or an equivalent perforated plate (hereinafter collectively referred to as a support net), and a water stream is applied from above the web. , moving the fibers constituting the web from above the wires of the support net or the non-perforated portion of the perforated plate and forcing them into the perforated portion of the support net, displacing the fibers of the wire portion of the support net; When forming the opening, the water flow is blocked by a special shielding net as described above before reaching the web, and the point where the water flow that has passed through the mesh of the shielding net overlaps with the protrusion of the wire of the support net. It can be manufactured by selectively opening holes only as an interference pattern.

The shielding net may be a perforated plate or a net (with openings arranged in a grid pattern at intervals of 19/10 to 11/10 or 10/11 to 10/19 of the spacing of the support net). (hereinafter collectively referred to as a shielding net) is used.

The mesh spacing of the shielding net is 19/10~1 of the mesh of the supporting net.
An interval of 1/10 or 10/11 to 10/19, more preferably,
By selecting the interval from 17/10 to 13/10 or from 10/13 to 10/17, the water flow that passed through the mesh of the shielding net selectively creates an interference pattern only at the points where it overlaps with the wire protrusions of the support net. By opening holes in the pores, it is possible to produce a nonwoven fabric with a lattice-like pattern, which is a feature of the present invention.

Therefore, it will be easily understood that by changing the ratio of the spacing between the meshes of the shielding net and the meshes of the support net within the above range, the spacing between the rows forming the grid can be freely set.

In principle, an interference pattern can be obtained even if the mesh spacing ratio is larger or smaller than the above range, but in reality, the shape of the mesh with larger pores becomes dominant and the interference pattern is impaired. , undesirable.

The method of carrying out the hole punching process of the present invention is as follows:
Preferably, the web is deposited on a support net, overlaid with a shielding net, and exposed to a stream of water while being moved.

Of course, the same effect can be obtained by fixing the support net/web/shielding net and moving the water flow, which is convenient for making small pieces in a laboratory.

The shielding net may be overlapped in contact with the web, but it is also a preferred embodiment to install it with some spacing, in which case the shielding net is moved at a different speed than the support net and the web. By that,
It becomes possible to easily change the interference interval.
Furthermore, by performing hole opening processing while varying the speed of the shielding net, various patterns such as a pattern in which the interference interval changes continuously can be easily obtained.

Regarding the materials of both the support net and the shield net,
There are no particular limitations, such as wire mesh made of metal such as stainless steel, phosphor bronze, or silver, or mesh made of monofilament or twisted multifilament of synthetic polymers such as polyamide, polyester, polyvinylidene chloride, etc. A net made of a material such as glass fiber or aramid fiber coated with a fluororesin is preferably used.

The weave structure of these nets is not particularly limited, and usually a plain weave structure is used, but diagonal weave and other structures are also preferably used in view of diversifying the opening patterns. Furthermore, it is permissible for the supporting net and the shielding net to have different structures, as long as the mesh relationship described above is within the scope of the present invention, and a novel interference pattern can be produced.

The support net may be a woven structure, a welded wire mesh made by simply overlapping wires crossed and welded at the intersections, or a plate-like material made by punching a film or sheet and perforating the openings in the mesh. .

The convex part of the wire of the support net is the part above the bend of the wire in the support net of the textile structure using wire, and corresponds to the point where the wire in the warp direction and the wire in the weft direction intersect.

The shielding net does not necessarily have to have a woven structure, and may be a welded wire mesh made by simply crossing and overlapping wires and welding the intersections, or a plate-like object made by punching the mesh portions.

The water flow used in the treatment of the present invention may be any water flow with the energy necessary to remove the web-constituting fibers on the support net from the wires that make up the net and create openings, and is usually 20 kg/water flow. A water stream jetted from a nozzle at a pressure of about cm ² G is used. There are no particular restrictions on the shape of the nozzle; nozzles that eject water into a fan or conical shape, slits that create a film-like water flow, or nozzles that form a rod-like flow are all suitable for processing. Depending on the fiber material of the web to be used and the thickness of the web,
It can be arbitrarily selected and used. However, in the case of water treatment using multiple nozzles, the spacing between the nozzles should be considered so that the water flow hits almost the entire width of the shielding net, as understood from the characteristics of the method of the present invention. In general, the spacing between the water streams from each nozzle should be shorter than the spacing between the wires of the shielding net. Furthermore, the water flow treatment may be carried out in multiple stages, and is recommended in that a clearer interference pattern can be obtained as long as the positions of the shielding net and the supporting net are kept in place during this process. .

If necessary, the water flow may be suctioned and forcibly removed from the back side of the support net. The nonwoven fabric that has been subjected to a hole-opening treatment using a water stream is further subjected to additional treatments such as entangling the fibers with a high-pressure rod-shaped water stream or adhesive treatment, if necessary, and then dried and wound up. However, these steps are not particularly limited, and known means and conditions may be arbitrarily selected.

[Action of the invention]

According to the nonwoven fabric having apertures with a special pattern of the present invention, as is clear from the manufacturing method of the present invention, the apertures and non-apertures forming the lattice pattern interfere with the shielding plate and the support plate. Since the pattern is obtained as a pattern, there is no clear boundary between the perforated non-woven fabric created by conventional patterned shielding plates, and the perforated area is smoothly and continuously connected to the non-perforated area, so that the non-woven fabric does not deform. There is no concentration of stress when subjected to it, and therefore the strength is not impaired. In addition, since the border between the perforated portion and the non-perforated portion is not clear, the border does not feel strange to the touch, and also provides a natural and beautiful interference pattern.

In the perforated nonwoven fabric of the present invention, the perforated part has a collection of fibers, so it gives a sense of volume, and since the fibers are intertwined, it is effective in developing strength as a nonwoven fabric, and it is also water permeable. Provides properties and breathability to nonwoven fabrics. On the other hand, the non-perforated part gives the nonwoven fabric wiping properties, water retention properties, covering properties, etc.
By appropriately selecting these patterns and ratios, nonwoven fabrics suitable for various uses can be provided.

Applications of the nonwoven fabric of the present invention include materials for the medical field such as gauze and hospital towels, various types of wipers such as industrial wipers, towels, dish towels, and wet napkins, cover cloths such as table cloths, seat covers, etc. is exemplified.

〔Example〕

Specific embodiments of the present invention will be described below with reference to Examples, but it goes without saying that the present invention is not limited thereto.

Example 1 Purified linter was dissolved in a copper ammonia complex aqueous solution, and according to the method of Japanese Patent Publication No. 52-6381,
It was extruded through a number of holes into a rectangular funnel-shaped coagulation bath, and together with the coagulation water supplied to the coagulation bath, it flowed out from the bottom of the coagulation bath through a slit, and together with the coagulation water, it flowed down in the form of a film. Thereafter, it was collected on a net conveyor made of polyester monofilament, washed with dilute sulfuric acid, and further washed with water to produce a spunbond web of cupra rayon.

This web was subjected to the hole-opening treatment of the present invention using the apparatus shown in FIG. That is, the web 5 is placed on a 20-mesh endless wire mesh (patterned mesh) 6 made of a plain weave structure of thin wire with a wire diameter of 0.457 mm, and from the nozzle 7 located 15 cm above the wire mesh, Spout 30Kg/cm ² G of water,
A fan-shaped water stream with a spread of approximately 20 degrees was applied to the web 5.

Between the nozzle 7 for water flow generation and the web 5, there is a plain weave structure of polyester monofilament with a wire diameter of 0.75 mm, with 16 meshes in the length direction and 16 meshes in the width direction.
An endless net of 15 meshes is used as a shielding net 8.
It was set up and moved in contact with the web 5.

A suction box 9 was provided on the back side of the support net to suck up the water flow passing through the web.

Kiyu Plus Spunbond Web is made by water flow.
The fibers in the openings are removed by the mesh and become wedged into the support net.

In this state, the support net was introduced into a hot air dryer 10, dried at 120° C., then humidity-controlled, and then wound up as a roll 11.

As shown in Figure 3, the obtained nonwoven fabric with aperture pattern has a checkered pattern with 0.3 mm to 0.7 mm apertures forming vertical and horizontal rows, and non-perforated areas are islands. It was left behind. The spacing between the openings forming the rows is 1.56mm in the length direction (vertical rows) of the nonwoven fabric.
It was 1.67 mm in the width direction (horizontal row).

When this perforated nonwoven fabric is used as a wet tissue, compared to Comparative Example 1 shown below,
It had an improved soft feel and thickness.

Comparative Example 1 A perforated nonwoven fabric of Kyupraspanbond was produced in exactly the same manner as in Example 1, except that the shielding net was not installed.

As shown in Figure 4, the pattern of the resulting perforated nonwoven fabric is a simple pattern in which all the intersections of the meshes of the support net are perforated, and when used as a wet tissue, it has a hard feel and a thick feel. It was also scarce.

Example 2 After blending 2-denier polyester staple fibers with a fiber length of 51 mm and 2-denier viscose rayon staple fibers with a fiber length of 51 mm at a ratio of 50:50, the fabric weight was 40 g/m ² using a random card. It was processed into a card web.

This web was subjected to the treatment of the present invention using the hole-opening treatment equipment shown in FIG. Here, the supporting net was made of stainless steel with a wire diameter of 0.46 mm and had a plain weave structure with 20 meshes in length and 18 meshes in width, and the shielding net was made of polyester monofilament with wires in length. A nonwoven fabric having a similar lattice pattern was produced by carrying out the same treatment as in Example 1, except that a net with a plain weave structure of 0.6 mm in diameter and 17 meshes and 15 meshes in width with a wire diameter of 0.7 mm was used.

〔Effect of the invention〕

Since the nonwoven fabric according to the present invention is configured as described above, the perforated portion and the non-perforated portion form an interference pattern, and the pattern is smoothly and continuously connected.
It has an excellent appearance, feel and texture. It also has an excellent ability to wipe away dirt. Furthermore, since the method for producing a nonwoven fabric of the present invention is carried out by using an appropriately selected combination of a support net and a shielding net, the desired nonwoven fabric can be obtained efficiently and easily.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the perforation pattern of the nonwoven fabric of the present invention, FIG. This is a photograph (×1.3 times) showing the shape of fibers in a nonwoven fabric having a hole pattern, and FIG. 4 is a photograph (×1.3 times) showing the shape of fibers in a conventional perforated nonwoven fabric. 1... Open hole, 2... Non-open hole part, 3, 4... Open hole row, 5
...web, 6...support net, 7...nozzle, 8...shielding net, 9...suction box, 10...hot air dryer.

Claims (1)

[Scope of Claims] 1. A nonwoven fabric having a perforated part and a non-perforated part, in which the perforated part has a size of 0.2 mm to 1.5 mm, which is approximately 1.2 times the size of the perforated part. Rows are formed in the longitudinal direction (longitudinal direction) and the width direction (horizontal direction) of the nonwoven fabric at intervals of 3 times from A nonwoven fabric characterized in that every other non-woven fabric is divided into non-perforated areas at approximately equal intervals and arranged to form a lattice pattern. 2. Place the web on a support net of 5 to 40 meshes, apply a water stream over the entire width of the web from above the web, and remove the web-constituting fibers from the convex portions of the wires forming the support net. , in producing a nonwoven fabric with openings, the mesh spacing of the support net installed between the web and the water source is 19/10 to 11/10.
Alternatively, by blocking the water flow with a shielding net having meshes at intervals of 10/11 to 10/19, only the points where the water flow passing through the openings of the shielding net overlap with the protrusions of the wire of the support net are exposed. A method for producing a perforated nonwoven fabric, which is characterized by forming perforations to generate perforations in a regular checkered interference pattern.