JPS6219537B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing ultrafine fiber entangled sheets by impinging a high-speed fluid flow on a fiber sheet, by providing a high-speed fluid flow with an appropriate angle of incidence to generate a reflected flow with respect to the sheet surface. A method for producing an entangled fiber sheet having a surface with small surface irregularities and good uniformity by colliding fluid streams to entangle ultrafine fibers (meaning that the entanglement is mainly done in ultrafine units) It is related to. At this time, in order to achieve entanglement between the ultrafine fibers, fibrillation of the ultrafine fiber-forming fibers and splitting of the ultrafine fiber bundle can be simultaneously achieved.

Conventionally, a web consisting of short fibers or filaments is placed on a conveyor net that moves at a constant speed.
A method has been proposed in which a paper sheet or a laminated sheet of a knitted fabric sandwiched between paper sheets is placed on both sides, and a high-speed fluid flow is impinged on this sheet to produce an entangled sheet. However, in these conventional methods,
Since the purpose is to intertwine and integrate the constituent fibers of the sheet, which are hardly entangled, impinging a high-speed fluid stream perpendicular to the sheet surface has also been commonly used.

Therefore, at the part where the high-speed fluid flow collides, the surface fibers move deep inside the fiber sheet to the back surface and entanglement occurs, but the range of entanglement on the surface of the fiber sheet is limited to the part where the high-speed fluid flow collided with it. The surface uniformity was extremely poor because the portions were deeply grooved and remained as uneven streaks. In order to improve this drawback, the pressure applied to the fluid is changed for each treatment, and the collision energy of the high-speed fluid flow is varied, and the treatment is repeated. A movement such as rotation or vibration is given to the injection nozzle in a plane parallel to the sheet surface, and a spiral or zigzag curve is drawn on the surface of the fiber sheet. A method has been proposed in which the nozzle hole is shaped like a slit and the high-speed fluid flow is made into a curtain-like flow.

However, even with these methods, a fiber entangled sheet with good surface uniformity could not be obtained.
That is, in the method (2), even if the treatment was repeated several times by changing the pressure, the portions struck by the last treatment remained as grooves, so that the surface still had large irregularities. In this method, the sheet surface is filled with the impact locus, so the area that is not hit is reduced, but a spiral or zigzag curve remains on the sheet surface, and the surface uniformity is still poor. It was hot. In addition, a device is required to give rotational motion or zigzag motion to the injection nozzle, and it requires a large amount of energy to move the heavy nozzle, which has disadvantages such as the need to make the device stronger and more complex. It was hot. In this method, it is extremely difficult to form a uniform curtain-like flow in the width direction, and the shape of the fluid flow becomes disordered immediately after being injected, making it difficult to achieve even the initial purpose of entangling the fibers. It was something that I couldn't do. Also, JP-A-54
As seen in Japanese Patent No. 64179, a treatment method has been proposed in which a liquid stream is impinged on a fabric having fuzz made of animal hair fibers and synthetic fibers to selectively push the fuzz of the synthetic fibers into the fabric. However, in this treatment method, deformation of the fabric structure such as misalignment is a disadvantage, so the angle of impact of the liquid flow on the fabric surface should be perpendicular or to an extent that does not cause a reflected flow that causes deformation of the fabric structure. It was only slightly inclined. In other words, in this treatment method, the fuzz of synthetic fibers is selectively moved, but since the purpose is to maintain the initial shape of the fabric structure, it is not possible to smooth out the unevenness of the fabric surface and make it uniform. It was hot.

The present invention is an extremely useful method that solves the drawbacks of the conventional method, and moreover, surprisingly, it relates to a method for producing an intertwined fiber sheet in which the fibers in the surface layer of the fiber sheet are extremely highly fibrillated and intertwined. It is something.

That is, the present invention provides a method for manufacturing a fiber entangled sheet by impinging a high-speed fluid stream discharged from a jet nozzle on a fiber sheet, the fiber sheet being mainly composed of ultrafine fiber-forming fibers or/and ultrafine fiber bundles. A high-speed fluid flow collides with the surface at an incident angle of 15 degrees or more and 70 degrees or less to fibrillate the ultra-fine fiber-forming fibers, split the ultra-fine fiber bundles, and at the same time entangle the ultra-fine fibers. This is a method of manufacturing a fiber entangled sheet.

That is, an object of the present invention is to have a fiber sheet with very little unevenness on the surface caused by the impact of a high-speed fluid flow, and to have a surface with good uniformity, and in which the fibers constituting the fiber sheet, especially the fibers in the surface layer, are made of ultrafine fibers. The purpose of the present invention is to produce an intertwined sheet with highly entangled fibers.

That is, according to the method of the present invention, by colliding a high-speed fluid flow with the sheet surface of a fiber sheet at an appropriate angle, fibrillation of ultrafine fiber-forming fibers and splitting of ultrafine fiber bundles are performed. At the same time, the ultrafine fibers are entangled, and the reflected flow generated within the range of the incident angle advances while smoothing the surface, making the surface less likely to become uneven. Moreover, when the method of the present invention causes collision compared to the conventional method, the collision area on the fiber sheet surface becomes larger even for the same high-speed fluid flow (when the cross section of the high-speed fluid flow is circular, the collision area of the conventional method The collision surface is a circle, and the collision according to the method of the present invention becomes a Da circle), so a wide area can be treated in one process, and the high-speed fluid can be processed by the increased collision area and the reflected flow. Because the flow collides with the surface fibers for a long time, the surface fibers become highly fibrillated and entangled. Moreover, since fibrillation and entanglement do not easily progress inside, it is easy to obtain a thin and dense surface entangled layer with extremely small irregularities.

In the present invention, the fiber sheet is mainly composed of ultrafine fiber-forming fibers and/or ultrafine fiber bundles. When a fiber sheet composed of fibers other than these is used, a grain-like surface with few irregularities cannot be achieved, or even if it is partially achieved, the degree of the improvement is extremely low. That is, in a fiber sheet composed of ordinary fibers other than ultrafine fiber-forming fibers or fibers that are not ultrafine, the fibers are not fibrillated even when processed by the method of the present invention, and therefore, there is no entanglement of the fibers. Almost never done. Therefore, the surface condition of the fiber sheet before the treatment remains almost unchanged after the treatment, and only a sheet with large surface irregularities and poor uniformity can be obtained.

Here, the ultrafine fiber-forming fiber is a fiber that can be fibrillated into a large number of ultrafine fibers by being hit by a high-speed fluid stream. Fibers, fibers with a chrysanthemum-shaped cross section in which one component is interposed radially between other components, multilayer bimetallic fibers, multilayer bimetallic fibers with a donut-shaped cross section, and melt-spun fibers made by mixing beads or chips of two or more types of polymers. Sea-island fibers, polymer mutual array fibers in which a large number of ultrafine fibers continuous in the fiber axis direction are arranged and aggregated and combined and/or partially combined with other components to form a single fiber, etc.
Two or more types of these fibers may be mixed or used in combination. Ultrafine fiber bundles and ultrafine fibers can be obtained by dividing these ultrafine fiber-forming fibers by applying chemical or physical action, or by removing bonding components. Alternatively, ultrafine fibers directly produced by a method such as super draw may be used.

Different resistance to damage from high-speed fluid flow,
Alternatively, multi-component ultrafine fiber-forming fibers made of two or more types of polymeric substances having different solubility in solvents are particularly preferably used as described below. By destroying the components with low breakability by hitting them with a high-speed fluid stream, other components can be fibrillated into ultra-fine fibers, and by extracting and removing some components with a solvent, the texture can be softened. A fiber entangled sheet with good surface uniformity and good shape retention can be obtained. Furthermore, when a part of the components is extracted and removed using a solvent and then subjected to high-speed fluid flow treatment using the method of the present invention, the ultrafine fiber bundles in the surface layer of the sheet are separated, and the surface uniformity of the ultrafine fibers is extremely highly entangled. A good fiber entangled sheet can be obtained. These intertwined fiber sheets are preferably used for artificial leather, especially silver-finished artificial leather. If it is not ultra-fine fiber,
A thin, dense, silver-like surface entangled layer cannot be obtained.

In the present invention, the ultrafine fibers refer to fibers of 0.5 denier or less. When surface uniformity, smoothness, or flexibility is particularly required, such as when the fiber entangled sheet obtained by the present invention is used for artificial leather, ultrafine fibers of 0.2 denier or less are preferably used. Further, when the surface portion of the fiber-entangled sheet obtained by the present invention treated with a high-speed fluid stream is used for the silver surface portion of silver-covered artificial leather, even thinner ultrafine fibers of 0.1 denier or less are preferably used.

As the fiber sheet, a nonwoven fabric, a knitted fabric, or a nonwoven fabric made of a combination of a knitted fabric and a fiber web made of the above-mentioned fibers can be used. However, if a high-speed fluid stream is suddenly injected from an oblique direction onto a paper sheet or a laminated web where the fibers are hardly entangled, the fibers will be blown away and sufficient entanglement will not be achieved. It is preferable to entangle the fibers with a stream or the like, or to temporarily or weakly adhere them using a glue such as polyvinyl alcohol. That is, the method of the present invention can also be preferably used as a method for uniformizing the surface of a fiber sheet that has been previously entangled by needle punching or vertically directed high-speed fluid flow.

Next, the fiber sheet thus obtained is placed on a moving conveyor net or along the surface of a perforated drum, and a high-speed fluid stream is impinged on the sheet surface of the fiber sheet at an incident angle of 15 degrees or more and 70 degrees or less. . When the incident angle is less than 15 degrees, fibrillation of the fibers occurs well, but the reflected flow becomes extremely strong, and the fibers are pulled out by the reflected flow and remain in clumps on the sheet surface, which deteriorates the uniformity of the surface. It gets worse and I don't like it. Also, the angle of incidence is 70
At higher temperatures, no reflected flow occurs, so if the reflected flow cannot smooth out the unevenness and make the surface uniform, the areas where the high-speed fluid collides will become deep grooves and remain as uneven streaks. , is not preferable because the surface uniformity is poor. When the incident angle is 15 degrees or more and 70 degrees or less, the surface fibers are highly fibrillated and entangled, resulting in a fiber entangled sheet with good surface uniformity.
More favorable results can be obtained by impinging the high-speed fluid stream from a direction oblique to the direction of travel of the fiber sheet while maintaining the angle of incidence at the above-mentioned angle. That is, at two points: the point where a perpendicular drawn from the center of the discharge hole of the injection nozzle to the sheet surface of the fiber sheet intersects the sheet surface, and the point where the fluid discharged from the center of the discharge hole hits the fiber sheet. The fiber sheet is discharged by striking the fiber sheet with a high-speed fluid stream such that the straight line thus determined has an angle of 10 degrees or more and 90 degrees or less with a straight line parallel to the traveling direction of the moving fiber sheet. The reflected flow of the high-speed fluid stream discharged from the holes travels along the grooves created by the collisions of adjacent high-speed fluid streams, which further improves the uniformity of the surface.

The fluid referred to here is a liquid or a gas, and in special cases it may contain extremely fine solids, but due to ease of handling, cost, etc.
Water is most preferably used from the viewpoint of the amount of collision energy as a fluid. Furthermore, depending on the purpose, various organic solvents capable of dissolving some components of the ultrafine fiber-forming fibers, or aqueous solutions of alkalis or acids such as sodium hydroxide can also be used. These fluids are pressurized and injected through small-diameter discharge holes or narrowly spaced slits to form a high-speed columnar flow or curtain-like flow, which is brought into contact with the fiber sheet to branch and entangle the fibers. The pressure applied to the liquid varies depending on the structure of the fiber sheet, the fineness of the fibers, and the ease of branching of ultrafine fiber-forming fibers or ^ultrafine fiber bundles. Relatively low pressure is sufficient, but for fibers that are difficult to branch, 70 to 300 kg/cm ²
high pressure is required. Further, by increasing the number of treatments, it is possible to increase the degree of branching and entanglement and make it more uniform, and the pressure may be changed each time the treatment is performed.

The shape of the injection nozzle body is not particularly limited, but a horizontally elongated one with small discharge holes with a hole diameter of about 0.01 mm to 0.5 mm arranged in one or several rows allows the high-speed fluid flow to flow into the sheet with an appropriate angle of incidence. It is convenient for colliding with the The distance between the holes is preferably in the range of 0.2 mm or more and 5 mm or less between the centers of the holes; if it is smaller than 0.2 mm, it becomes difficult to process the holes and the high-speed fluid flow tends to come into contact with adjacent holes. Also 5mm
If the size is larger, these problems will disappear, but even if the fluid flow impinges on the fiber sheet from an oblique direction, the surface cannot be completely covered, so multiple treatments will be required.

Further, the method of the present invention and at least one of the conventional methods described above may be combined.

The fiber entangled sheet obtained by the method of the present invention has a highly fibrillated surface layer and is composed of densely intertwined ultrafine fibers, and has a good surface uniformity. It is preferably used for silver-finished artificial leather having a face-like skin layer. That is, after impregnating the fiber entangled sheet with a resin solution and/or resin dispersion such as polyurethane and solidifying it wet or dry to apply the resin, or without applying these resins, a high-speed fluid flow is applied. A thin microporous layer and/or non-porous layer made of a resin such as polyurethane is formed on the treated surface, and further graining, extraction and removal of some fiber components, coloring, rolling, etc. The silvered artificial leather obtained has a soft texture with a sense of unity, and has a structure very similar to natural leather. In addition, the voids of the densely entangled fibers in the surface layer of the fiber-entangled sheet are filled with resin and smoothed and densified by pressing or the like.
Furthermore, the silver-finished artificial leather has a composite skin made of resin and ultra-fine fibers with an ultra-thin resin film layer formed as needed, and not only has a soft texture with a sense of unity, but also scratch resistance and Because of its good bending resistance and shear fatigue resistance, it is preferably used in a variety of applications, including silver-finished artificial leather for clothing, uppers for shoes, handbags, bags, belts, bags, gloves, and outer leather for balls. In addition, by impregnating the fiber-entangled sheet with resin and buffing the high-speed fluid treatment surface with emery paper, high-quality and bag-like artificial leather with a good feel and a dense fluff of short microfibers can be obtained. be able to.

In addition, the fiber entangled sheet obtained by the method of the present invention has excellent flexibility and does not easily lose its shape, and has excellent shape retention, especially in wet conditions containing liquids such as water. Therefore, it is preferably used for fabrics, towels, various filters, grip members such as grips, various covers, furniture, automobile, and glass polishing cloths, polishing cloths, cassette pads, wiping cloths, etc.

The examples shown below are for the purpose of clarifying the present invention, and the present invention is not limited thereto. In the examples, parts and percentages are by weight unless otherwise specified.

Example 1 The sea/island ratio is 20/80, the sea is a copolymer of 20 parts of 2-ethylhexyl acrylate and 80 parts of styrene (hereinafter referred to as AS resin), and the islands are made of nylon 6 and AS.
A 4.0 denier, 51 mm staple of a polymeric interlayer fiber in the form of an equal mixture of resins containing a large number of ultrafine fiber components of nylon 6 in the islands is used to form a web through a card and a cross wrapper. Needle punching was performed using a needle with one hook to primarily entangle the polymeric mutually arranged fibers to produce a fiber sheet.

The obtained fiber sheet was placed on a conveyor net moving at a constant speed, and a pressure of 100 Kg/ ^cm2 was applied from an injection nozzle in which holes with a diameter of 0.13 mm were lined up with a pitch of 0.6 mm between the centers of the holes. The water was sprayed at high speed and collided with the fiber sheet under several conditions described below to produce an entangled fiber sheet.

A. The jet nozzle is installed so that the discharge holes are arranged perpendicular to the traveling direction of the fiber sheet, and a high-speed water stream collides with the sheet surface of the fiber sheet at right angles from directly above. The same process is performed a total of 5 times to create a fiber entangled sheet. A was produced.

B The injection nozzle is installed perpendicular to the direction of travel of the fiber sheet, but a high-speed water stream impinges on the sheet surface at an incident angle of 65 degrees in the direction of travel of the fiber sheet, and the same treatment is performed for a total of 5 times. A fiber entangled sheet B was produced by spinning.

C Set the injection nozzle at 60° in the direction of travel of the fiber sheet.
The water jet discharged from the center of the discharge hole hits the fiber sheet at the point where the perpendicular drawn from the center of the discharge hole of the injection nozzle to the fiber sheet surface intersects with the sheet surface. point 2
The straight line determined by the points and points is at an angle of 30 degrees with respect to a straight line parallel to the traveling direction of the fiber sheet, and the fiber sheet is positioned at an incident angle of 65 degrees with respect to the sheet surface of the fiber sheet. A fiber-entangled sheet C was produced by impinging a high-speed water stream on the sheet and performing the same treatment five times in total.

The fiber-entangled sheet A had many streaks left in the form of many streaks parallel to the direction of travel of the sheet from the last fifth treatment, and the surface had large irregularities and poor uniformity.

In the fiber entangled sheets B and C, the AS resin, which is a bonding component of the polymer mutually arranged fibers, is destroyed by the impact of the water stream on the surface layer of the sheet, and the fiber entangled sheets B and C are extremely highly fibrillated compared to the fiber entangled sheet A. Most of the surface was filled with densely entangled ultrafine fibers, resulting in small irregularities and excellent uniformity. In addition, in the fiber entangled sheet B, a pattern of parallel stripes was observed in the direction of sheet travel, but in the fiber entangled sheet C, there was no such pattern and the surface uniformity was extremely excellent. .

Next, a small amount of polyurethane binder was applied to these fiber-entangled sheets, and the surface layer of the water-treated surface was filled with polyurethane resin to form a skin layer in which the ultrafine fibers and polyurethane resin were mixed and integrated. Thereafter, the AS resin was extracted and removed by immersion in trichlorethylene and dried. next,
A grain pattern was formed on the surface using an embossing device, dyed with an acidic metal-containing dye, and finished using a conventional finishing method to produce artificial leather with a skin.

In the case of the fiber-entangled sheet A, even after finishing it into silver-covered artificial leather, many streaks formed by the water treatment remained on the surface, and the skin was rough and lacked uniformity. It was hot.
In addition, when it was held in the hand, it felt like it had a hard core, and when it was rubbed too hard, cracks appeared along the lines, and the appearance and feel were poor. On the other hand, the fiber entangled sheets B and C had smooth surfaces that followed the grain pattern, and had a soft and unified feel. In addition, although I rubbed it vigorously, no cracks were observed and the appearance remained almost unchanged.

Example 2 95 parts of polystyrene and 5 parts of polyethylene glycol
A 3.8 denier, 51 mm piece of polymer interlayer array fiber in a form in which 16 ultrafine fibers are contained in one filament, with 45 parts of a mixture of 50% and 50% of polyethylene terephthalate as a binding component and 55 parts of polyethylene terephthalate as an ultrafine fiber component. A nonwoven fabric was made using the same method as in Example 1.

The obtained non-woven fabric was placed on a conveyor net moving at a constant speed, and water under a pressure of 70 kg/cm ² was applied to the non-woven fabric using the same injection nozzle as in Example 1 and struck at a right angle from directly above the non-woven fabric at high speed. The same treatment was performed a total of 4 times. The treated surface of the obtained nonwoven fabric was densely intertwined with the polymer array fibers fibrillated into ultrafine fibers, but it was extremely uneven with many grooves formed parallel to the direction of movement of the conveyor net. .

Next, the nonwoven fabric thus obtained is placed on the conveyor net, and the point where a perpendicular drawn from the center of the discharge hole of the injection nozzle to the sheet surface of the nonwoven fabric intersects with the sheet surface, and the point where the perpendicular line drawn from the center of the discharge hole of the injection nozzle intersects with the sheet surface, A straight line determined by the two points at which the water flow hits the fiber sheet is relative to the traveling direction of the nonwoven fabric.
The same treatment was carried out twice in total by impinging the high-speed water stream on the sheet surface of the nonwoven fabric at an angle of 45 degrees and at an incident angle of 70 degrees.

The obtained nonwoven fabric had a good surface uniformity, with almost no grooves formed in the initial treatment. In addition, the surface had a very good feel and did not easily lose its shape even when rubbed tightly.

Example 3 In Example 1, the fiber sheet obtained by needle punching and primary entanglement was immersed in hot water at 95°C to shrink and dry to remove water.
The obtained fiber sheet was placed on a conveyor net moving at a constant speed, and while the same injection nozzle as in Example 1 was moved in the longitudinal direction of the injection nozzle parallel to the sheet surface of the fiber sheet with an amplitude of 3 mm. , a water stream was perpendicularly impinged on the sheet surface at a pressure of 100 Kg/cm ² , and the same treatment was carried out twice in total.

In the obtained fiber sheet, the polymer array fibers on the treated surface were fibrillated into ultrafine fibers and were densely entangled, but a zigzag pattern was formed on the surface and the surface uniformity was not good. Ta.

Next, install the above injection nozzle so that the water flow collides with the sheet surface at an incident angle of 60 degrees, and while making the piston movement of the injection nozzle in the same way as above,
An additional treatment was carried out on the previously treated fiber sheet at a pressure of Kg/cm ² .

As a result, the zigzag pattern almost disappeared, and fibrillation and entanglement further progressed, resulting in a fiber sheet with good surface uniformity.

Claims (1)

[Scope of Claims] 1. A method for producing a fiber entangled sheet by impinging a high-speed fluid stream discharged from a spray nozzle on a fiber sheet, the fiber sheet being mainly composed of ultrafine fiber-forming fibers or/and ultrafine fiber bundles. A high-speed fluid flow collides with the sheet surface at an incident angle of 15 degrees or more and 70 degrees or less to fibrillate the ultra-fine fiber-forming fibers, separate the ultra-fine fiber bundles, and at the same time entangle the ultra-fine fibers. A method for manufacturing a fiber-entangled sheet featuring features. 2. Two points: a point where a perpendicular drawn from the center of the discharge hole of the injection nozzle to the sheet surface of the fiber sheet intersects with the sheet surface, and a point where the fluid discharged from the center of the discharge hole hits the fiber sheet. Claim 1, characterized in that the fiber sheet is struck with a high-speed fluid flow such that the straight line determined by is at an angle of 10 degrees or more and 90 degrees or less with the traveling direction of the sheet. A method for producing a fiber entangled sheet. 3. The method for producing an entangled fiber sheet according to claim 1, characterized in that a resin is applied to the surface of the side hit by the high-speed fluid flow to form a grain-like skin layer. 4. The method for producing an entangled fiber sheet according to claim 1, characterized in that needling, adhesion, or temporary adhesion is performed in advance when the ultrafine fibers are entangled by colliding with the high-speed fluid flow.