JPH01321961A - Non-woven fabric having specific opening pattern and production thereof - Google Patents

Abstract

PURPOSE:To provide the subject non-woven fabric having excellent filth- wiping-out ability and capable of being used as a substitute for woven fabric by arranging opening having a specific dimension regularly between non-opened portions in such a grid state to divide the non-opened portions in both the longitudinal and lateral directions. CONSTITUTION:Openings 1 having a size of 0.2-1.5mm are arranged so as to form longitudinal rows 3 and lateral rows 4 at longitudinally and laterally independent intervals (approximately 1.2-3 times the size of the opening) and at approximately equal intervals. The rows of the openings each independently surround non-opening portions 2 at approximately equal intervals every 2-9 openings to form a grid pattern. The rows forming the grid may be one row such as the row 4 or plural rows such as the longitudinal row 3.

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 deposited on an endless belt, a cylindrical wire mesh, or a perforated board, and a water stream is applied to it while moving, and the water flow moves the fibers that make up the web, and the holes in the wire mesh are removed. Japanese Patent Publication No. 36-7274 discloses a method for manufacturing a perforated nonwoven fabric in which the fibers at the intersections of wire mesh or unperforated portions are removed to form perforated portions.

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, it is disclosed in Japanese Patent Publication No. 47-18069 that the perforations of the plate (support plate) on which the web is to be deposited have a special pattern, with holes having a lace-like pattern. ing.

Furthermore, Japanese Patent Publication No. 54-10666 discloses a method in which a composite pattern of large lace-like openings and small openings in the net-like material is produced by combining a net-like material with the perforated portion of the support plate.

Also, regarding the spacing of the water nozzles that generate rod-shaped water streams,
By varying the spacing of the perforations on the board on which the web is to be deposited, only the areas where the nozzles and the perforations coincide are marked with the pattern of perforations, and the areas where the nozzles do not coincide with the perforations are left unperforated and unpatterned. A method of imparting a striped pattern to a web in the longitudinal direction is disclosed in Japanese Patent Application Laid-Open No. 61-6355.

Further, it is disclosed in Japanese Patent Publication No. 10666/1983 that the water flow hitting the web is blocked by a shielding plate perforated in a special pattern to limit the perforated area and to give the perforated part a shape and pattern. ing.

[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 it requires a lot of labor, and production is interrupted during the exchange, resulting in losses.

Also, Special Publication No. 47-18069 and Special Publication No. 51-10
The method of creating a pattern on a support plate with a pattern, such as the method disclosed in Japanese Patent No. 666, requires replacing the support plate in order to change the aperture pattern, and there are problems in industrial implementation similar to those described above. In addition, the openings in the support plate should be discontinuous and independent in order to maintain the strength and shape of the support plate, and the width of the non-opening part should be at least a certain width. There are restrictions, and 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 there are limitations to the opening pattern of nonwoven fabric. 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, the feel and texture are bad. 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 openings independent, and it is difficult to make them minute in terms of machining accuracy and the strength of the molded plate, so the openings have to be made large. All I could get was non-woven fabric.

These lace-like large pore openings are not effective in wiping away dirt, as there are few non-open surfaces that are effective in wiping contaminated surfaces of nonwoven fabrics, such as wet wipers and other household items and industrial wipers. In addition, 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 partition the non-porous areas both vertically and horizontally can greatly increase the wiping surface. Furthermore, 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 on methods to implement this, 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, and the perforated part has a diameter of 0.2 n+m to 1.5 n+m.
Openings with a size of mm form rows in the longitudinal direction (longitudinal direction) of the nonwoven fabric and in the width direction (horizontal direction) of the nonwoven fabric at intervals of about 1.2 to 3 times the size of the openings. However, the rows of holes are arranged independently in the vertical and horizontal directions to form a lattice pattern, with non-holes divided at approximately equal intervals every 2 to 9 holes. This is achieved using a non-woven fabric with special characteristics.

A preferred manufacturing method for manufacturing the perforated nonwoven fabric is 5
The web is placed on a support net of ~40 meshes, and a water stream is applied over the entire width of the web from above the web to remove the web-constituting fibers from 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.
By blocking the water flow with a shielding net having meshes at intervals of ~11/10 or 10/11 to 10/19, only the points where the water flow passing through the openings of the shielding net and the wires of the support net overlap. The method is characterized by forming holes in a regular checkered interference pattern.

To explain the perforation pattern, which is a feature of the present invention, with reference to the drawings, FIG. They are arranged to form vertical rows 3 and horizontal rows 4 at equal intervals, and in this example, they form a lattice pattern surrounding a portion 2 that has no holes at all. The row of apertures forming the lattice may be one row, such as horizontal row 4 in FIG. 1, or may be composed of a plurality of rows, such as two vertical rows 3.

Note that the rows of openings may not be completely completed over the entire nonwoven fabric, and that the number of rows may change to an adjacent row midway or the number of rows may partially change is subject to 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 + nm or less, and from this If it is large, 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 size of the opening 1 is less than about 0.2 +n+n, the function of the opening becomes poor, which is not preferable.

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

The spacing between the pores forming each row should be selected within a range of about 1.2 to 3 times the size of the pores; anything outside this range is preferred since the strength of the nonwoven fabric may be impaired. do not have. 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, cupra (copper ammonia method rayon), and cotton 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, it is preferable that the fiber consists of or contains cellulose fiber. Things are often liked.

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

The method for producing a web for producing the nonwoven fabric of the present invention is not particularly limited, and any conventionally known method can be used. In other words, put short fibers in water! A method in which short fibers are dispersed by an air stream and collected on a net, a method in which stable fibers are made into a web using a card, and a so-called spun method in which a web is formed by directly connecting to spinning. Bond method, etc.

In order to process these webs into the perforated nonwoven fabric with the special pattern of the present invention, it is necessary to use a mesh of 5 to 40 meshes, more preferably 8 to 30 meshes, or an equivalent perforated plate (hereinafter referred to as a supporting mesh). (collectively referred to as )),
A water stream is applied from above the web, and the water stream moves the fibers constituting the web from above the wire of the support net or the non-perforated portion of the perforated plate and pushes them into the hole portion of the support net. When removing the fibers from a portion of the wire of the support net to create an aperture, before the water stream reaches the web,
It can be manufactured by shielding with a special shielding net as described above and selectively opening holes as an interference pattern only at the points where the water flow that has passed through the mesh of the shielding net overlaps with the wire of the support net.

As a shielding net, the distance between the meshes of the support net is
Perforated plate or net (with openings arranged in a grid pattern with intervals of 9/10 to 11/1.0 or 10/11 to 10/19)
(hereinafter collectively referred to as a shielding net) is used.

The distance between the meshes of the shielding net is 19/10 to 11 of the mesh of the support net.
/10 or 10/11 to 10/19, more preferably 17/10 to 13/10 or 10/13 to 10/
By selecting an interval of 17 mm, the water flow passing through the mesh of the shielding net selectively opens holes as an interference pattern only at the points where they overlap with the wires of the support net, thereby creating a nonwoven fabric with a lattice pattern, which is a feature of the present invention. can be manufactured.

Therefore, it is 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.

A suitable method for carrying out the hole-opening process of the present invention is to deposit the web on a support net, place a shielding net on top of the web, and expose the web to a stream of water while moving the web.

Of course, the same effect can be obtained by fixing the supporting net/web/shielding net and moving the water flow, which is convenient for making small pieces in the 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 this case, by moving the shielding net at a speed different from that of the support net and the web, it is possible to easily change the interval of interference. Furthermore, if the hole opening process is performed 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.

There are no particular restrictions on the material of both the support net and the shield net (wire mesh made of metal such as stainless steel, phosphor bronze, or brass, polyamide, polyester,
Nets made of monofilaments or twisted multifilaments of synthetic polymers such as polyvinylidene chloride, nets made of glass fibers or aramid fibers coated with fluororesin, etc. are all suitable for use.

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 to form openings in the mesh. .

The shielding net does not necessarily have to be a woven structure; it can be a welded wire mesh made by simply overlapping wires and welding the intersections, or
A plate-like material with mesh portions perforated by punching may be used in the same manner.

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 constituting the net and create pores, and is usually 20 kg/water flow. A water stream ejected from a nozzle at a pressure of about cntG is used. There are no particular restrictions on the shape of the nozzle, such as a nozzle that spreads the ejected water flow in a fan shape or a cone shape, a slit that creates a film-like water flow,
Any nozzle or the like that forms a rod-shaped flow can be arbitrarily selected and used depending on the fiber material of the web to be treated, the thickness of the web, etc. However, when water treatment is performed using multiple nozzles, the spacing between the respective 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 of the water streams from the nozzles should be shorter than the spacing of 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. Because it is obtained as a pattern, conventional patterned fabrics do not have clear boundaries like the perforated nonwoven fabrics due to shielding plates, but are smoothly and continuously connected from the perforated area to the non-perforated area, so the nonwoven fabric is deformed. There is no concentration of stress when subjected to stress, so the strength is not compromised. 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-porous portion imparts wipeability, water retention, covering properties, etc. to the nonwoven fabric, and by appropriately selecting these patterns and ratios, it is possible to provide a nonwoven fabric suitable for various uses.

Applications of the nonwoven fabric of the present invention include gauze, materials for the medical field such as hospital gloves, industrial wipers,
Examples include various wipers such as towels, dish towels, and wet napkins, and power cloths such as table cloths and seat covers.

〔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 extruded through a number of holes into a rectangular funnel-shaped coagulation bath according to the method disclosed in Japanese Patent Publication No. 52-6381, and the coagulation solution supplied to the coagulation bath was After flowing out from the bottom of the coagulation bath through the slit together with the water for use, and letting it flow down together with the coagulation water in the form of a film,
Collected on a net conveyor made of polyester monofilament, then washed with dilute sulfuric acid, further washed with water,
A spunbond web of cupra rayon was produced.

This web was subjected to the hole-opening treatment of the present invention using the apparatus shown in FIG. That is, the web 5 has a wire diameter of 0.457
Consisting of a plain weave structure of brass wire of 20 mm
Replace it on the mesh's endless wire mesh (patterned mesh) 6, and from the nozzle 7 located 15 cm above it, 30k
g/cnfG of water was ejected to hit the web 5 as a fan-shaped water stream with a spread of 1° to 20°.

Between the nozzle 7 for water flow generation and the web 5, there is a wire diameter of 0.
An endless net having a plain weave structure of 75+n+n polyester monofilaments and having a length of 16 mm and a width of 15 mm was installed as a shielding net 8 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 that penetrated the web.

In the Cupras spunbond web, the fibers in the openings are removed by the water flow and become wedged into the support net.

In this state, the support net is guided into the hot air dryer 10,
After drying at 120° C., the humidity was adjusted and then wound up as a roll 11.

The resulting nonwoven fabric with aperture pattern has a checkered pattern with 0.3 mm to 0.7 n+m apertures arranged in vertical and horizontal rows, as shown in Figure 3. The holes were left in the form of islands. Here, the spacing between the openings forming the rows was 1.56 mm in the length direction (vertical rows) of the nonwoven fabric and 1.67 mm in the width direction (horizontal rows).

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

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

The pattern of the resulting perforated nonwoven fabric was a simple pattern in which all the intersections of the meshes of the support net were perforated, as shown in Figure 4, and when used as a wet tissue, it felt hard and
It also lacked a sense of thickness.

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

This web was subjected to the treatment of the present invention using the hole-opening treatment equipment shown in FIG. Here, as a support net, the wire diameter is 0.46 mm.
Made of stainless steel, 20 meshes in length and 1 mesh in width.
A wire mesh with a plain weave structure of 8 meshes was used, and the shielding mesh was made of polyester monofilament with a wire diameter of 0 in the vertical direction.
．． Example 1 except that a net with a plain weave structure of 6 n+m of 17 mesh and a width of 15 mesh with a wire diameter of 0.7 mm was used.
A nonwoven fabric with a similar lattice pattern was produced by processing in the same manner as above.

〔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, resulting in excellent appearance, feel, and wind resistance. It has a combination. It also has an excellent ability to wipe away dirt. Furthermore, since the method for manufacturing 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 the drawing]

FIG. 1 is a diagram illustrating the perforation pattern of the nonwoven fabric of the present invention, FIG. A photograph (Xl, 3x) showing the shape of fibers in a nonwoven fabric with a hole pattern,
FIG. 4 is a photograph (Xl, 3x magnification) showing the shape of fibers in a conventional perforated nonwoven fabric. 1...Open hole, 2...Non-hole part, 3.4
... Opening row, 5... Web, 6... Support net, 7... Nozzle, 8... Shielding net,
9...Suction box, 10...Hot air dryer.

Claims (2)

[Claims] 1. A nonwoven fabric having a perforated part and a non-perforated part, in which the perforated part has apertures with a size of 0.2 mm to 1.5 mm, which are approximately 1.2 to 3 times the size of the perforated part. Rows are formed in the longitudinal direction (vertical direction) and the width direction (horizontal direction) of the nonwoven fabric at intervals of , a nonwoven fabric characterized in that non-perforated portions are divided at approximately equal intervals and arranged to form a lattice pattern. 2. The web is deposited on a 5-40 mesh support net,
A stream of water is applied over the entire width of the web from above,
When manufacturing a nonwoven fabric with openings by removing the web-constituting fibers from the wire forming the support network, the distance between the meshes of the support network installed between the web and the water source is 1.
By blocking the water flow with a shielding net having meshes at intervals of 9/10 to 11/10 or 10/11 to 10/19, the water flow passing through the openings of the shielding net and the wire of the support net overlap. A method for producing a perforated nonwoven fabric characterized by forming perforations only at points and generating perforations in a regular checkered interference pattern.