JP4435738B2 - Method for producing ultrashort fibers - Google Patents

Description

The present invention provides an extremely short fiber having a fiber length of 0.1 mm or less by cutting a fiber bundle obtained by bundling a large number of yarns made of a group of long single fibers into a bundle. about the production how of short fibers.

  Conventionally, various fiber bundles are used to bundle long fibers made of a thermoplastic synthetic polymer such as polyester and polyamide into a fiber bundle and cut the fiber bundle to obtain short fibers having a length of several to several tens of millimeters. Cutting devices are commonly used. For example, as such a cutting device, a bundle of fibers is wound around a cutter roller having a large number of cutting blades radially provided, and the fibers wound on the cutting blade are pressed against the cutting blade continuously to a predetermined length. A roller cutter type fiber bundle cutting device that cuts the blade is used. A so-called guillotine cutter type fiber bundle cutting device has also been known for a long time, in which a fixed blade and a moving blade are provided as shear blades, and a fiber bundle is pushed and cut by a predetermined cutting length with respect to these shear blades.

  In an environment where such a conventional fiber bundle cutting device is used, recently, very short synthetic fibers to be mixed into some cosmetics, ultrafine fibers used for flocs with a soft texture, or short chopped elasticity The demand for textiles has increased. Accordingly, short fibers having a fiber length of 0.1 mm or less after cutting have been required.

  However, in the case of the former roller cutter type fiber bundle cutting device, for example, it is required to extremely reduce the interval between adjacent cutting blades of a group of cutting blades provided radially on a rotating cutter roller. However, in such a case, the fibers cut between the cutting blades are clogged, making it difficult to discharge them. In addition, there is a problem with the thickness of the cutting blade itself, and it is a limit to shorten the cutting fiber length. There is.

  On the other hand, in the case of the latter guillotine cutter type fiber bundle cutting device, it is possible to cope with a cutting fiber length of about 0.5 mm. However, when trying to cut thin and long fibers with small single fiber fineness using a conventional fiber bundle cutting device, the fibers are bent or buckled due to the elasticity of the fibers themselves, and perpendicular to the fixed blade. Will not abut. In addition, it becomes extremely difficult to adjust the clearance between the fixed blade and the movable blade, and a lot of miscuts such as oblique cutting and uneven cutting length occur.

  Then, in order to obtain a short fiber having a uniform fiber length, it is necessary to select and take out only those that are normally cut from a large number of miscut fibers. However, such a sorting and taking out operation is extremely complicated, and when the number of miscut fibers that do not fit within the allowable cut length increases, the yield of the fibers that have been cut correctly also deteriorates.

  In view of this, an apparatus for solving the above-described problems of the guillotine cutter type fiber bundle cutting apparatus has been proposed in, for example, Japanese Patent Application Laid-Open No. 2003-11962. In this prior art, a guide for wrapping the supplied fiber bundle with a continuous sheet-like material is attached prior to cutting the continuously supplied long fiber bundle. Then, the fiber bundles wrapped with the sheet-like material are cut after being overlapped so as to wrap the long-fiber bundles traveling by the continuous sheet-like material running along with the fiber bundles through this guide roller. In other words, the fiber bundle itself is made rigid by wrapping a fiber bundle that is flexible and difficult to cut with a sheet-like material, and by cutting the rigid fiber bundle, it is intended to cut into short fibers of a predetermined length. is there.

  However, even if such a guillotine cutter type fiber bundle cutting device is used, the fiber length that can be cut is 0.1 to 30 mm, and it is extremely difficult to obtain a cut fiber of 0.1 mm or less with a good yield. Have difficulty. Moreover, as a sheet-like material used to coat the fiber bundle in order to obtain such short fibers, organic polymer films such as paper, polyolefin, polyester, and cellophane, fabrics, and nonwoven fabrics must be used.

  However, when such a sheet-like material is used, it is required to separate the cut fiber and the sheet-like material after cutting. However, it is difficult to completely separate them, and even a slight amount may be mixed into the cut fiber as cutting waste. In addition, as the cut fiber length approaches 0.1 mm, the fiber bundle needs to be restrained more rigidly in order to cut more reliably. Therefore, a sheet-like material that can be used is required to have a more rigid property, but naturally, the rigidity of such a sheet-like material is limited not only in the materials used but also in the handling properties. .

  If it does so, since the yield accompanying a miscut will fall significantly and production efficiency will also fall, it is difficult to obtain the short fiber which has a cut fiber length of 0.1 mm or less substantially. Moreover, in order to increase the productivity of short fibers in large quantities, it is necessary to prepare as thick a fiber bundle as possible by bundling a large number of single fiber groups. However, as the fiber bundle is made thicker, even if the outer periphery of the fiber bundle is wrapped with a film-like sheet and a strong restraining force is applied, the restraining force on the single fibers inside the fiber bundle is weakened. If it does so, restraint force will become weak and it will become difficult to cut | disconnect the fiber bundle which consists of a single fiber group in the state which can move freely even if it is small.

  That is, when each single fiber is taken out from the single fiber group constituting the fiber bundle, this single fiber is extremely thin, for example, 0.001 to 10 dtex, and is rich in elasticity. It easily deforms in the direction in which it acts and escapes from the cutting blade. Therefore, it is extremely difficult to normally cut the fiber bundle with a high yield without miscutting to a very short length of 0.1 mm or less.

  From the viewpoint of restraining and cutting fiber bundles, it is proposed in Japanese Patent Application Laid-Open No. 63-35829 to cut aramid fibers that are difficult to cut by a conventional cutting device. Has been. This prior art is a technique in which an aramid fiber is impregnated with a molten thermoplastic resin and cured, and the cured resin is pelletized with a pelletizer while containing the fiber. However, this prior art is intended to obtain a fiber reinforced plastic in which shortcut fibers are kneaded as they are without the need to remove the impregnated thermoplastic resin from the cut fiber bundle. Therefore, it is a technique that is not anticipated to be taken out at all, not only the cut fibers are isolated and taken out from the thermoplastic resin. In addition, as described above, this conventional technique is to pelletize the fiber after impregnating the fiber with a thermoplastic resin. The fiber-containing resin is cut to a cutting length of 0.1 mm or less by a known pelletizer and pelletized. It is extremely difficult.

  Furthermore, in order to increase the productivity of ultrashort fibers, it is required to bundle a very large number of long and thin single fibers to form a fiber bundle having a total fineness exceeding 10,000 decitex and harden it with a thermoplastic resin. However, it is extremely difficult to sufficiently impregnate a fiber bundle having such a large diameter with a high-temperature thermoplastic resin having a high melt viscosity. Therefore, even if the fiber bundle is impregnated with the thermoplastic resin, it cannot be avoided that a single fiber group that cannot be restrained by the thermoplastic resin partially occurs inside the fiber bundle. For this reason, the single fiber group which is not fully restrained with a thermoplastic resin will arise, and miscutting will increase inevitably.

The present invention aims to solve the above-mentioned problems of the prior art, and at the same time, when obtaining an extremely short fiber having a fiber length of 0.1 mm or less, it is stably manufactured by suppressing miscutting as much as possible. It is to provide a method that can. In the description of the present invention described below, "Umatsutsumizai" relates the terms and "Umatsutsumizai", called "Umatsutsumizai" a case where a liquid state, the case where the solid state "filled First of all, let me add that it is called “wrapping material”.

  The inventors of the present invention have made extensive studies in order to achieve the above-mentioned problem, but in the technical idea of “cutting a fiber bundle” as in the prior art, a cut fiber having an extremely short fiber length of 0.1 mm or less. It was found that it was difficult to obtain. That is, when one single fiber of the single fiber group constituting the fiber bundle is taken out, the single fiber is extremely thin and rich in elasticity. For this reason, the single fiber group to be cut easily deforms by the force received from the cutting blade during cutting and escapes from the cutting blade. Therefore, it has been found that it is extremely difficult, if not impossible, to normally cut a fiber with a high yield without miscutting it to an extremely short length of 0.1 mm or less.

Therefore, in order to solve this problem, in the process of trial and error in which various ideas are experimented, the present inventors have decided not to “cut the fiber bundle” but to “cut the fiber bundle”. And came up with the idea that ultra-short fibers of 0.1 mm could be obtained. However, the problem here is how to cut a fiber bundle in which a large number of thin single fibers are bundled one by one. However, in this regard, the fiber bundle, including its internal, if integrated by the embedding processing of embedding in Umatsutsumizai consisting ice, that can be a very good target cutting body I came up with an idea.

Here, as the present invention, there is provided a method capable of producing an ultrashort fiber stably while suppressing miscut as much as possible when obtaining an ultrashort fiber having a fiber length of 0.005 to 0.1 mm. That is, in the present invention, single fiber groups having a single fiber fineness of 0.001 to 10 dtex are aligned so as to be parallel to each other in the fiber longitudinal direction and bundled so that the total fineness is 10,000 to 10 million dtex. forming a fiber bundle, buried by selecting water as a packing agent to embedding the fiber bundle, to prepare the cutting material obtained by embedding processing the fiber bundle in ice a Umatsutsumizai solidifying the water the cutting end face of the fiber bundle the ice is embedding at a temperature not liquefied cutting into flake, a method of obtaining very short fibers having the following cut fiber length 0.1 mm.

At this time, as a method for producing ultrashort fibers that do not cause miscutting, it was found that the alignment of fibers embedded in the embedding material in one direction is important. Therefore, a large number of bobbins wound with multifilament yarns composed of a large number of single fiber groups are prepared. Then, the yarns, which have been unwound at a constant tension, are wound around the skein (skein) frame (winding frame) while being combined with each other and wound around the winding frame. A fiber bundle having a total fineness is produced. And since the location where the single fiber group was linearly aligned and wound up in parallel with each other in the portion overlapped on the winding frame is formed, this location is used. That is, the embedding process which solidifies the both ends of the linearly aligned part wound up by embedding agents, such as an adhesive agent, cuts the solidified part, and produces a to-be-cut material. Alternatively, both ends of the linearly drawn and wound portion are clamped and gripped with a pair of fixing tools, adhesive tape, etc., and the fiber bundle is cut at both outer ends of the pair of fixing tools to form a linear shape. A fiber bundle that is satisfactorily aligned is prepared. In addition, when it is necessary to manufacture very short fibers in large quantities, the fineness of single fibers is 0.001 to 10 dtex, and the total fineness of the fiber bundle constituted by these single fiber groups is 10,000 to 1000. It is important to set it to 10,000 dtex.

Next, when a fiber bundle that is well aligned in a straight line is produced in this way, the embedding process is performed, but air remains in the fiber bundle. Therefore, the fiber bundle is left in a well-aligned state in the container to be embedded, and is preferably vacuum degassed. Then, a previously defoamed embedding agent in a liquid state is filled into the container, and the fiber bundle is impregnated while being surrounded by the embedding agent. At this time, it is preferable to perform the embedding process while evacuating the inside of the container with an evacuation device such as a vacuum device under a weak negative pressure with respect to the atmospheric pressure so that bubbles do not remain inside. As a result, almost no bubbles remain in the embedded fiber bundle, so that each single fiber constituting the fiber bundle can be sufficiently restrained. For this reason, when the binding force does not act, the fiber bundle resembles that is extremely flexible and easily escapes from the cutting blade, and can transmit a sufficient cutting force when the cutting blade comes into contact with each single fiber. Accordingly, by cutting the bundle of fibers thus embedded into a thin piece, it is possible to produce a large amount of ultrashort fibers having a fiber length of 0.005 to 0.1 mm without miscutting.

In the present invention, as the embedding agent, water that is available in large quantities, at low cost and easily, and that is extremely easy to handle is used. If such water is used, since the viscosity of water is very low, it can easily penetrate into the fiber bundle. Further, in order to allow easy entry into the fiber bundle, nonionic surfactants such as esters and ethers of polyalkylene glycol, anionic surfactants such as fatty acid, alkyl phosphate, sulfonate, and alkali metal salts of sulfate, Add a small amount of a surfactant such as a cationic surfactant such as a quaternary ammonium salt or an amphoteric surfactant such as an alkali metal salt of an aminocarboxylic acid or an alkylbetaine to spread the water to every corner of the fiber bundle. Also good.

Also, or Umatsutsumizai consisting of water is hardly enters, rather than utilizing a thick fiber bundle Too air to leave or hardly remaining inside the fiber bundle, a number of small fiber bundles or fiber bundle was flat Are arranged in parallel, and it is preferable to embed the small fiber bundle or the flat fiber bundle. By doing in this way, the bubble contained in a to-be-cut material can be removed very effectively. Furthermore, when the water is frozen, the gas dissolved in the water is bubbled. Therefore, the upper part of the lid member of the freezing container that performs the freezing process (embedding process) is slightly heated by the heating means. Then, it is preferable that the icing process is performed by the icing unit so that the bubbles that have come out in the water do not remain while the upper surface of the water is depressurized by the exhaust device while controlling so that the water surface does not freeze.

In the present invention, as described above, ultrashort fibers are manufactured by cutting. As the cutting means, a well-known machine tool such as a planer, a sharpener, a planer, or a milling machine, or an improved version thereof is used. Can be used. In such a case, erected in parallel with each dense state a number of the cutting material such way to result was fabricated as described above. Then, in such a standing state, these are embedded again in the embedding material to form an integral block, and this is newly supplied to the work table as a work material. Good. Then, a large amount of ultrashort fibers can be easily manufactured. However, even in the cutting to be cutting material by any means, as embedding material forming part of the cutting material is not a phase change from a solidified state to liquefied state, holding a cutting material It is preferable to provide a cooling means and / or a cooling means for cooling the holding means. Or it is also preferable to cool a cutting blade depending on the case.

Oite poles producing how the short fibers of the present invention described above, as the embedding material, using ice. This is because ice has an advantage that it can be separated from ultrashort fibers easily manufactured by natural drying, hot air drying, freeze drying, or the like from a workpiece cut into a thin piece. At that time, in a composite fiber (conjugate fiber) in which two kinds of polymers are bonded together, there is a problem that when a large temperature change is applied, a dimensional change occurs or the bonded polymers are separated from each other. In particular, care must be taken when drying optical interference fibers as described in JP-A-11-241223. This is because this type of fiber has a specific polymer layer thickness that is specified in the order of microns, so that the incident light interferes with the alternately laminated polymer and exhibits a bright color. This is because the thickness is controlled so as to have a thickness. Therefore, in such a case, it is preferable to use a freeze-drying method that can remove moisture while still in a frozen state.

  The ultrashort fiber to be produced by the present invention can be obtained from a synthetic fiber made of a polymer such as polyester, polyamide, or polyolefin, or a composite synthetic fiber in which two or more kinds of polymers are combined. I don't mean. That is, it can be obtained from natural fibers such as silk thread, cotton thread and hemp thread, or semi-synthetic fibers such as cellulose fiber and acetate fiber.

  Generally, a short fiber whose fiber length is cut from 1 mm to several tens of mm is a yarn composed of a group of single fibers having a fineness of 0.001 to 10 dtex as a single fiber (also referred to as “filament”). It is manufactured by shortly cutting fiber bundles that are bundled together so as to be parallel to each other in the fiber longitudinal direction.

  Also in the present invention, in the process of producing short fibers as in the conventional technique, a process of preparing a fiber bundle by bundling a plurality of yarns composed of a large number of single fiber groups is required. In this preparation step, it is important to bundle multifilament yarns in a state in which the fiber bundles are aligned in one direction. This is because, in the present invention, when the single fiber group constituting the fiber bundle is oriented in an oblique direction without being aligned in one direction, the embedded single fiber group is cut in the embedding material in the cutting direction. However, it is fixed in an oblique direction without being fixed vertically. Then, the embedding treatment of the fiber bundle with the embedding material will be described later. When the fiber bundle embedding treated in this state is cut, the single fiber group fixed in the oblique direction is cut vertically. Instead, it is cut obliquely.

  Therefore, in order to solve this problem, in the present invention, as a first embodiment, at least one bobbin formed as a bobbin by winding a multifilament yarn composed of a number of single fiber groups is firstly taken. prepare. Then, the yarn bundle is drawn out from these spools and applied with a predetermined tension, while the yarn is overlaid on a take-up frame such as a well-known take-up frame, and the fiber bundle is in an aligned state. Get. Then, without removing the fiber bundle obtained in this way from the take-up frame, the fiber bundle is subjected to embedding treatment while the tension at the time of winding is applied, and the fiber bundle with the tension applied is embedded. It is embedded and integrated.

  Alternatively, as a second embodiment of the present invention, a fiber bundle formed by overlapping and winding a fiber bundle formed by wrapping a large number of yarns while the tension at the time of winding is still applied. Fully restrain both ends. Here, with regard to the restraint at both ends of the fiber bundle described above, the outer periphery of the both ends is wound with an adhesive tape so that the single fiber group constituting the fiber bundle cannot move freely, or is gripped with a strong force by a fastening tool. Can also be done. It can also be carried out by adhering and fixing the single fibers constituting the fiber bundle by impregnating and adhering the adhesive only to the both ends.

  If it does in this way, unlike the said 1st embodiment, it can remove from a winding frame by cut | disconnecting in the tape part which fixes the both ends of a fiber bundle, or the part fixed by adhesion | attachment. For this removal, if a fixing jig such as a stretcher is attached so that the both ends of the fiber bundle can be gripped and the state where the tension is applied can be maintained, it is cut from the winding frame. When the target fiber bundle is removed, the tension for aligning the single fiber group can be removed without being relaxed once.

  In addition, when not using fixing jigs, such as a stretcher, before fixing a fiber bundle in an embedding material, a predetermined tension | tensile_strength is again provided to the fiber bundle both ends after the cutting | disconnection. At this time, at the both ends of the fiber bundle after cutting, the single fiber group is restrained without changing the position of each other by the adhesive tape as described above. Can be easily returned to.

  Then, by embedding and integrating the fiber bundle in the embedding material in a tensioned state, the single fiber group constituting the fiber bundle is again aligned and fixed in the embedding material in a uniformly arranged state. be able to. Then, the degree of freedom of movement of the single fiber constituting the embedded fiber bundle is completely restricted by the embedding material. Therefore, even when the cutting blade comes into contact with the embedded single fiber group at the time of cutting, the single fiber group can appear in a state where it cannot easily move due to restraint by the embedding material.

  Next, embodiments of a method for manufacturing a fiber bundle suitable for manufacturing the ultrashort fiber of the present invention described above and an apparatus therefor will be specifically described below with reference to the drawings.

  FIG. 1 and FIG. 2 are schematic explanatory views for explaining two embodiments schematically illustrated in order to explain the method for producing ultrashort fibers of the present invention. In the embodiments illustrated in FIGS. 1 and 2, the embodiment illustrated in FIG. 1 will be described first.

  In the embodiment of FIG. 1, reference numeral 1 denotes a winder, which can use a well-known Hank winder for winding skeins, and 2 is a spinning means composed of a yarn guide or the like. . Further, P is a bobbin group composed of at least one bobbin, and in the illustrated example, is composed of three bobbin bodies (P1, P2, P3,...). Accordingly, multifilament yarns (y1, y2, y3,...) Composed of a large number of filaments (monofilaments) are wound around the bobbin bodies (P1, P2, P3,...). Each of these yarns (y1, y2, y3,...) Is guided to the yarn joining means 2, and after being joined through the yarn joining means 2, is wound on the winder 1.

  In this example, when winding on the winder 1, the yarns (y1, y2, y3,...) Are unwound and pulled out from the spools (P1, P2, P3,...), And then combined. However, although it winds up simultaneously, it can also cut | disconnect a combined yarn process. That is, the yarns (y1, y2, y3,...) Are unwound from the spools (P1, P2, P3,...), Pulled out, combined, and wound only by the combined yarns y. In this system, a single thread wound body suitable for supplying to the machine 1 is formed, and the combined yarn y is supplied to the winder 1. When such a method is used, when a large number of fiber bundles F are supplied by a large number of winders 1, a large number of bobbin bodies (P1, P2, P3, ...) need not be prepared, and more efficient work is possible.

  In the present invention, for example, a yarn group y in which yarns (y1, y2, y3,...) Composed of multifilaments (many single fiber groups) having a single fiber fineness of 0.001 to 10 dtex are combined. The fiber bundle F is adjusted so that the total fineness becomes 10,000 to 10,000,000 dtex by arranging them so as to be parallel to each other in the fiber longitudinal direction. Therefore, the winding machine 1 is wound to obtain a fiber bundle F having a predetermined total fineness by repeatedly winding the yarn group y supplied from the bobbin body group P a necessary number of times. A frame 10 is provided. Therefore, the winding frame is provided with a winding width regulating member 11 that regulates the winding width of the fiber bundle F to a predetermined length as a constituent member of the winding frame 10.

  This will be described with reference to FIG. 1. The winding frame 10 is composed of a hexagonal frame (frame), as shown at each apex on the hexagonal winding frame 10. Twelve winding width restricting members 11 are provided. Therefore, the combined yarn group y is not wound directly on the winding frame 10 but is wound in the non-contact state as a fiber bundle F on the winding width regulating member 11. However, in order to further stabilize the winding tension, the shape of the winding frame 10 is preferably a regular polygon having a larger number of sides, such as the regular hexagon of this example. It may be. In the following description of the embodiments of the present invention, for convenience of explanation, the hexagonal winding frame 10 will be described as a representative. However, as described above, the present invention is limited to such embodiments. It goes without saying that it is not something.

  In the fiber bundle F formed on the winding frame 10 in this way, only the portion Fs arranged in a straight line suitable for cutting is used as a material to be cut for producing ultrashort fibers. Therefore, in the example shown in FIG. 1, since the winding frame 10 has a hexagonal shape, the material to be cut whose six fiber bundles (Fs1, Fs2,..., Fs6) are embedded by the embedding material. It will be used as a material for manufacturing.

  In FIG. 1, reference numeral 12 denotes a tension detecting means, which is used for tension control at the time of winding while controlling the tension of the yarn group y supplied so as to fall within a predetermined tension range. In this way, by supplying the yarn group y to the winder 1 while controlling the tension, when the yarn group y is wound on the winding width regulating member 11, the alignment property is improved. The necessary tension can be applied. However, in the example of FIG. 1, the “longitudinal cutting method” is adopted as a method of unwinding the yarns (y1, y2, y3,...) From the spools (P1, P2, P3,...). However, when the yarn (y1, y2, y3,...) Is unwound in this manner, unwinding and twisting is performed once for each unwinding. For this reason, in order to prevent such unwinding and twisting from entering, the yarn (y1, y2, y3,...) Is unwound by rotating the bobbin (P1, P2, P3,...). A pre-emption method can also be adopted.

  Further, although not shown in the example of FIG. 1, when the yarns (y1, y2, y3,...) Are unwound and drawn out from the bobbin bodies (P1, P2, P3,...), They are used for weaving. A tension compensator 3 (31, 32, 33,...) That is commonly used in a preparation process such as a warping machine that warps warp yarns is provided for each yarn (y1, y2, y3,...). preferable. However, the tension compensator 3 is provided on each of the bobbin bodies (P1, P2, P3,...), And thereby the yarns (y1, y2, etc.) such as the bobbin bodies (P1, P2, P3,...). It is commonly used to stabilize the unwinding tension so that the unwinding tension does not fluctuate significantly when unwinding y3,. As the tension compensator 3, a commercially available ceramic product having a low coefficient of friction and wear resistance can be suitably used, and a detailed description thereof will be omitted here.

  As described above, in the present invention, the yarns (y1, y2, y3,...) Are tensioned from the spools (P1, P2, P3,...) So that the unwinding tension does not change abruptly.・ Unwind using Compensator 3. At this time, it is further preferable to wind the fiber bundle F with a constant tension set in advance in order to improve the alignment property of the fiber bundle F wound around the winding frame 10. This is the same when the combined yarn process is separated and separated, or when the combined yarn process is continued as in the example of FIG. However, in the following description, a case where the spinning process is combined with the winding process to the winding frame 10 by the winder 1 will be described.

  The winding machine 1 of the present invention includes tension detecting means 12 for detecting the tension of the yarn group y to be supplied in order to control the winding tension. Then, the winding speed of the winder 1 is controlled so that the tension detected by the tension detecting means 12 becomes constant. At this time, a torque motor may be employed as a drive motor (not shown) of the winder 1 that rotationally drives the winding frame 10, and the winding frame 10 may be wound at a constant torque. That is, in the present invention, it is important that the yarn group y is wound over the winding frame 10 with a predetermined constant tension regardless of the winding method or the winding mechanism.

  Moreover, in the winding machine 1 of the present invention, a winding machine having a traverse mechanism 13 is used, and the yarn group y supplied to the winding frame 10 when winding the fiber bundle F on the winding width regulating member 11. It is a preferable aspect that the wire is traversed by a traverse guide (not shown) corresponding to the winding width of the winding width regulating member 11. This is because, in this way, the winding property of the fiber bundle F can be further improved by winding the yarn group y on the winding width regulating member 11 while orderly aligning the yarn group y in the width direction. .

  Thus, in the fiber bundle F wound up on the winding frame 10, each fiber bundle (Fs1, Fs2,..., Fs6) wound up at six locations corresponding to each side with the hexagonal winding frame. ) Can be in a state of being tensioned by the tension applied at the time of winding, and is wound linearly. For this reason, since the fiber bundle (Fs1, Fs2,..., Fs6) of this linear portion is in a very good aligned state, if this portion is embedded as it is with the above-described embedding material, an ultrashort fiber It becomes a material suitable as a work material for obtaining.

  It should be noted that the fiber bundles (Fe1, Fe2,..., Fe6) wound around the respective apexes of the hexagonal frame other than the fiber bundles (Fs1, Fs2,..., Fs6) of the linear portions wound on the winding frame 10. ), This part is impregnated with a quick-drying adhesive that infiltrates well into the single fiber group. Then, it is a preferred embodiment in the present invention to fix the fiber bundle (Fe1, Fe2,..., Fe6) by solidifying the adhesive. This is because, even if the fiber bundle F shifts from a tensioned state to a relaxed state for some reason such as cutting of the fiber bundle F and contraction of the winding frame 10, if such a situation is revealed, at least the fiber This is because the freedom of movement is restricted so that the single fiber group constituting the bundle F does not move so as to change its position. For this reason, by returning the fiber bundle F to the tension state again, it can be easily returned to the original good alignment state.

  Note that the fixed portions (Fe1, Fe2,..., Fe6) of the fiber bundle are not arranged in a straight line, and thus are not suitable as a material to be cut to obtain ultrashort fibers. Therefore, it is preferable in the present invention to fix the adhesive which cannot use such portions (Fe1, Fe2,..., Fe6) as the work material. However, in the present invention, as will be described later, fixing the fiber bundle (Fe1, Fe2,..., Fe6) with an adhesive is a preferred embodiment, but this is not essential. I'll add a note just in case.

  The winding frame 10 of the present invention described above is a regular polygonal frame such as a hexagonal frame illustrated in FIG. However, the winding frame of the present invention is not limited to such an example, and a winding frame 10 ′ other than the regular polygon frame illustrated in FIG. 2 can also be used. The winding frame illustrated in FIG. 2 is provided with two winding width regulating members 11 ′ at both ends of the rod-shaped winding frame 10 ′, and each of the two winding width regulating members 11 ′ is used as a folded portion. The yarn group y ′ is overlaid on the winding width regulating member 11 ′ to obtain a fiber bundle F ′ having a predetermined total fineness.

  However, in such an example, the yarn group y combined by the winding width regulating member 11 ′ is folded back. For this reason, fluctuations in tension become larger compared to a polygonal winding frame such as the hexagonal winding frame 10 of FIG. Therefore, in the winder 1 ′ used in such an example, it is necessary to reduce the influence of a significant change in the unwinding tension when unwinding the yarn group y ′ from the bobbin body group P ′. It is. For this reason, it is preferable to provide a tension compensator 3 ′ for each bobbin P ′ to suppress an increase in the fluctuation range of the unwinding tension. In this way, after suppressing the fluctuation range of the unwinding tension, the rotation of the servo motor 14 'is controlled while the winding tension is detected by the tension detecting means 12'. Then, the yarn group y 'combined by the combining means 2' is wound on the rod-shaped winding frame 10 'by a traverse device 13' with a predetermined winding tension.

  With the fiber bundle manufacturing method and apparatus of the present invention described above, a fiber bundle adjusted to have a predetermined total fineness of 10,000 to 10 million dtex can be obtained in a well-aligned state. Therefore, in order to obtain ultrashort fibers by cutting, a process for embedding a fiber bundle that has been well aligned in this way with an embedding material will be described below with reference to FIGS. However, it explains in detail.

  In the present invention, the embedding process using the embedding material can be performed while being wound around the polygonal winding frame 10 illustrated in FIG. 1 or the rod-shaped winding frame 10 ′ illustrated in FIG. 2. . Here, FIG. 3 is an embodiment using a method of embedding the fiber bundle F wound up using the hexagonal winding frame 10 illustrated in FIG. a) is a schematic plan view, and FIG. 3B is a schematic side view.

  FIG. 4 is an explanatory view (plan view) schematically illustrating the treatment tank 4 for embedding the fiber bundle F with the embedding material 5. Furthermore, FIG. 5 is a schematic diagram for explaining a step of embedment by immersing the winding frame 10 with the fiber bundle F wound around in the treatment tank 4 filled with the liquid embedding agent 5. FIG. 5A is a schematic plan view, and FIG. 5B is a schematic side view. FIG. 6 is a schematic side view schematically illustrating a state where the liquid embedding agent 5 is cooled and solidified and then taken out from the treatment tank 4.

However, as described above, in the present invention, relates to the term "Umatsutsumizai" and "Umatsutsumizai", where a liquid state called "Umatsutsumizai", the case where the solid state "filled Let me reiterate what I mean by “wrapping”. In addition, in the example shown in FIGS. 3-6, although the winding frame used what has the hexagon illustrated in FIG. 1 as a representative example, as long as the main point of this invention is satisfied, it is limited to this. It goes without saying that there is nothing.

  In the present invention, the embedding process can be performed by directly using the winding frame 10 with the fiber bundle F being wound. At this time, as a first step, when the take-up frame 10 is removed from the take-up machine 1, the aligned state of the fiber bundle F taken up on the take-up width regulating member 11 is maintained well as described above. Therefore, it is necessary not to deform the fiber bundle F in the tension state. Therefore, it is preferable that the winding frame 10 be a mechanism that can be freely detached from the rotary drive shaft if the lock is released. Then, as illustrated in FIG. 3, the winding frame 10 can be removed from the winder 1 as it is without directly touching the wound fiber bundle F.

When the winding frame 10 is removed as described above, as a next step, the treatment tank 4 having a hexagonal shape as illustrated in FIG. 4 corresponding to the hexagonal winding frame 10 of the present example. Prepare. And this processing tank 4 is filled with the liquid embedding agent 5 (water) .

  Next, as illustrated in FIG. 5, the winding frame 10 with the fiber bundle F wound is immersed in the treatment tank 4 filled with the liquid embedding agent 5 as described above. In this process, the details will be described later, but in order to remove bubbles present in the fiber bundle F, the winding frame 10 in a state where the fiber bundle F is wound is temporarily put together with the processing tank 4 in a vacuum container. The fiber bundle F that has been vacuum defoamed and vacuum defoamed may be embedded. In this way, the fiber bundle F is immersed in the liquid embedding agent 5 so that the embedding agent 5 is sufficiently impregnated between the single fiber groups constituting the fiber bundle F, and then cooled to the embedding agent. The single fiber group which comprises the fiber bundle F by solidifying 5 is embedded in the solidified embedding material 5.

  The term “flat” as used in the present invention refers to the maximum length in the flat extension direction when viewed in the cross section of the fiber bundle F (cross section perpendicular to the longitudinal direction of the single fibers constituting the fiber bundle). (Referred to as “horizontal length”) and the minimum length in the perpendicular direction (referred to as “vertical length”) (referred to as “aspect ratio = vertical length / horizontal length”). 3 or less. For example, the “aspect ratio” will be specifically described in the embodiment of FIGS. 11A and 11B. In the fiber bundle F having the rectangular cross section of FIG. Is given by “short side length / long side length”, and in the fiber bundle having the elliptical cross section of FIG. 11B, the “aspect ratio” is given by “length of short axis / length of long axis”. It is done.

  As the last step, as illustrated in FIG. 6, a linear portion necessary for cutting the embedded fiber bundle F into ultrashort fibers is cut out with a cutter to obtain a workpiece. For example, in FIG. 6, the part shown with the dashed-dotted line is cut out with a cutter. Then, for example, the linear fiber bundle (Fs1, Fs2,..., Fs6) portion shown in FIG. 1 can be used as a material to be cut when an ultrashort fiber is manufactured.

  In the embodiment described above, the winding frame 10 or 10 ′ is taken out from the winder 1 or 1 ′ as it is, and the fiber bundle F or F ′ is wound around the winding width regulating member 11 or 11 ′. In this invention, it is preferable to use such a method. However, the present invention is not limited to such an example, and as described above, the fiber bundle F or F ′ treated with an adhesive or a tightening jig is cut out from the winding frame 10 or 10 ′ and the winding frame. The embedding process can also be performed in a state separated from 10 or 10 '. Therefore, such an embedding process will be described in detail below with reference to FIGS.

  FIG. 7 is a schematic explanatory view (plan view) schematically illustrated for explaining an embodiment of the embedding process performed in a state in which the fiber bundle F is separated from the winding frame 10. In this embedding process, as illustrated in FIG. 7, half of the embedding agent filling container 6 is attached to the linear fiber bundle (Fs1, Fs2,..., Fs6) illustrated in FIG. In addition, this embedding agent filling container 6 has a halved structure, and when the halved portions are united, both ends and halves that fasten the linear fiber bundle (Fs1, Fs2,..., Fs6) portions. It is attached to the linear fiber bundle (Fs1, Fs2,..., Fs6) in a state of being tightened through a sealing material such as silicon rubber so that the liquid embedding material does not leak from the split portion. At this time, in order to improve the sealing performance, a liquid or paste-like sealing agent may be used supplementarily for the sealing portion.

  In this way, with the embedding agent filling container 6 attached to the linear fiber bundle (Fs1, Fs2,..., Fs6), the liquid embedding agent 5 is introduced into the embedding agent filling container 6 at the inlet 6a. And the outlet 6b. And while extruding the bubble which exists in the fiber measure F and the air which exists in the embedding agent filling container 6, the embedding agent 5 is filled in the embedding agent filling container 6. FIG. However, at this time, if water is used as the embedding agent 5, the viscosity is low, so that the fiber bundle F can be satisfactorily entered. Next, in such a state, if the embedding agent filling container 6 is cooled to a minus temperature, the water inside freezes, and the fiber bundle F can be successfully embedded with the embedding material made of ice.

  Further, as already described, the fiber bundles (Fe1, Fe2,..., Fe6) wound around each vertex of the hexagonal winding frame 10 as shown in FIG. Then, after completely restraining the freedom of movement of each single fiber, there is a method of cutting this part and removing it from the winding frame. However, in this case, without cutting the fiber bundle F, the winding frame 10 can be retracted so that only the winding frame 10 is contracted and removed, and only the fiber bundle F can be taken out. As a specific example of such a contraction structure, for example, a structure in which six rod-like frames extending radially supporting the winding width regulating member 11 shown in FIG. 1 can be folded by a telescope structure or a hinge or the like. It is conceivable to make it extendable.

  When the fiber bundle F can be taken out from the winding frame 10 in this way, the fiber bundle F is returned to a good alignment state again by holding both the bonded portions and applying a predetermined tension. Can be made. However, in this case, when removing the fiber bundle F from the winding frame 10, it is necessary to consider that the fiber bundle F to be taken out does not deform as much as possible. This is because if the fiber bundle F to be taken out is greatly deformed, the single fiber group deforms the fiber measure F other than the portion fixed by the adhesive at the time of deformation and changes the position of each other. This is because, if only a low tension is applied, it is difficult to return each single fiber to the original position under the influence of inter-fiber friction or the like.

  Therefore, in order to prevent the fiber bundle F from being greatly deformed when the fiber bundle F is removed as shown in FIG. Are attached to the linear fiber bundle (Fe1, Fe2,..., Fe6) portion wound around the winding frame 10. Then, it is preferable to take measures so as to cut the fiber bundle F outside the jig 7 so that the fiber bundles (Fe1, Fe2,..., Fe6) in this portion are not greatly deformed. If it does in this way, it can replace with the winding frame 10 illustrated in FIGS. 3-6, and can use for an embedding process with the jig | tool as shown in FIGS. It can be carried out.

  In general, each single fiber group constituting the fiber bundle F is very thin and flexible. Therefore, since it is easily elastically deformed in the direction in which the cutting force acts and escapes, it is not easy to manufacture an extremely short fiber having a fiber length of 0.1 mm or less as described above. Therefore, in the present invention, the single fiber group constituting the fiber bundle F is fixed by the embedding material and restrains the degree of freedom of movement, thereby revealing a state where it cannot move easily. Then, in this state, the fiber bundle F fixed by the embedding material with the cutting blade is cut into a thin piece. It should be noted that the property required of the embedding agent to achieve this purpose is required to be able to change to a low-viscosity flow state, so that the fiber bundle can be easily surrounded and wrapped. In addition, it is required to be able to enter the gap inside the fiber bundle from the outer periphery.

  In the present invention, the liquid embedding material is allowed to enter the inside of the fiber bundle without any hindrance and restrains the freedom of movement of the long monofilament. Is described in detail below with reference to the drawings.

  FIG. 9 is a front view in which a cross section is given to a part of the embodiment schematically embedding the fiber bundle in the method for producing ultrashort fibers of the present invention. FIG. 10 is a plan sectional view in the direction of arrows AA in FIG. Further, FIG. 10A is an embodiment of a small fiber bundle having a flat rectangular cross section (cross section perpendicular to the longitudinal direction of the fiber), and FIG. 10B is not flat. Each of the embodiments of small fiber bundles having a circular cross section is shown.

  Regarding the reference numerals shown in these drawings, F is a small fiber bundle, 12 is an embedding agent (embedding material), 13 is a container, 13a is an inlet for an embedding material that has changed into a liquid state, and , 14 respectively indicate gripping members. Here, as described in detail above, the fibril bundle F is converged in a state in which the yarn groups y are arranged in parallel and aligned in a straight line, and then the fibril bundle F has a fixed length. It was produced by cutting both ends so as to be.

Next, the small fiber bundle F group is fixed to the plurality of small fiber bundles F manufactured as described above by the gripping members 14 that grip and fix both ends of each small fiber bundle F. At this time, the fibril bundle bundles F held and fixed by the grasping member 14 are adjacent so that the embedding agent 12 phase-changed in a liquid state can surround each fibril bundle F and enter the inside thereof. It is important to dispose an appropriate gap W between the small fiber bundles F. Note that since the difficulty of entering the small fiber bundle F differs depending on the properties of the embedding agent 12 to be used, the interval W is a property that can be determined as appropriate by an experiment. For example, in the present invention, preferably to 0.5mm or more because it uses a phase change the water in the liquid form, particularly preferably a 2mm or more.

  In the present invention, the freedom degree of movement of the long single fiber group constituting each fibril bundle F is fixed and restrained by the embedding material 12. For this reason, after the embedding agent 12 that has changed into a liquid state is introduced between the small fiber bundles F so as to surround the outer periphery of the small fiber bundle F group, the deepest central portion of each small fiber bundle F It is important that it can be easily reached. Therefore, in order to embody this, the “maximum required entry distance” required when the embedding agent 12 phase-changed into a liquid enters the deepest center of each fibril bundle F becomes a problem.

  Thus, the “maximum required approach distance” referred to in the present invention will be described with reference to FIG. In FIG. 11, FIG. 11A shows a small fiber bundle F whose cross section has a flat rectangular shape, and FIG. 11B shows a small fiber bundle F whose cross section has a flat elliptical shape. Each case is illustrated. L represents a center line.

  In these two embodiments, the embedding agent 12 phase-changed in a liquid state is arranged so that the fibril bundles F are not in contact with each other at a predetermined interval W. The outer periphery of F can be easily surrounded. Therefore, the next problem is that the embedding agent 12 surrounding the outer periphery of each fibril bundle F in this way can easily reach the deepest inside of each fibril bundle F. At this time, in the embodiment of FIG. 11A, the “maximum required distance dmax” takes the same value along the longitudinal direction of the cross section as shown, but in the case of FIG. As shown in the figure, the maximum required entry distance dmax is taken at the position where the thickness of the fibril bundle F in the cross section becomes the largest.

In the present invention, it is important that the embedding agent 12 can easily enter the deepest central portion of the small fiber bundle F. Therefore, it is important that the maximum required entry distance dmax does not exceed 5 mm. is there. This is because when narrow single fiber groups of 0.001 to 10 dtex are focused, each gap between these single fiber groups is extremely small. As a result, the embedding agent 12 cannot sufficiently enter the interior thereof. For this reason, in order for the embedding agent 12 to enter the deepest part of the small fiber bundle F, the thickness of the small fiber bundle F cannot be increased, and therefore the maximum required entry distance dmax does not exceed 5 mm. It is necessary to make it.

  At this time, in a state where the fibril bundles F are closely arranged, it becomes difficult for the embedding agent 12 to enter the interior of the fibril bundles F. Then, if each fibril bundle F is arrange | positioned without contacting each other with the predetermined space | interval, there will be no restriction | limiting in particular about the arrangement | positioning. In addition, if the preferable arrangement example of such a small fiber bundle F is given, when the cross section of the small fiber bundle F is circular as shown in FIG. Arbitrary arrangements such as arrangements and staggered arrangements can be appropriately selected as long as the above-mentioned gist of the present invention is satisfied.

By the way, if air bubbles or the like are mixed in the fiber bundle F that has been embedded as described above, a single fiber group that is not restrained appears due to the embedding agent (embedding material), which may cause miscutting. Become. For this reason, in the present invention, it is necessary to prevent bubbles and the like from being mixed into the embedded fiber bundle F. Therefore, a method for preventing bubbles from remaining in water (ice) as an embedding agent (embedding material) will be described below.

  At that time, the embedding agent 12 that can be suitably used has excellent permeability and dispersibility by mixing a surfactant as a property that allows easy entry into a single fiber group. preferable. This is because such a surfactant can be more easily impregnated with the embedding agent to the inside of the small fiber bundle F when used in the embedding agent 12 (which has been changed into a liquid state). In addition, as such an embedding agent, the water which mixed surfactant can be illustrated especially.

  By the way, although it was mentioned above that the small fiber bundle F used as the object of embedding processing has a micro space | gap in the inside, it is that the air is interposing in the space | gap in the normal state. Needless to say. Therefore, if air continues to exist in the fibril bundle group F, no matter how much the fiber bundle that bundles the fibril bundle group F is immersed in the embedding agent 12, it is interposed between the single fiber groups. Therefore, the embedding agent 12 cannot completely enter the small fiber bundle F.

  Therefore, when the embedding process is performed with the embedding agent 12, it is preferable to remove the air existing inside the small fiber bundle F in advance, and the air is stored in the container by vacuum suction inside the container to be embedded. It is preferable to expel it from the inside. And the embedding agent can be more satisfactorily impregnated inside the fiber bundle by performing the embedding process after removing the air existing inside the single fiber group constituting the fiber bundle. Therefore, this point will be described in detail with reference to FIG. 12 schematically showing an apparatus for manufacturing a fiber bundle according to the present invention. In FIG. 12, 13 is a container for performing embedding processing similar to that illustrated in FIG. 9, further, 15 is a defoaming tank, 16 is a vacuum suction device, and 17 is a vacuum pipe. Show.

  In the defoaming apparatus configured as described above, the small fiber bundle F group is put into the container 13 as illustrated in FIGS. 9 and 10. And after putting the container group 13 in the defoaming tank 15 and sealing it so that the inside of the defoaming tank 15 becomes airtight, the air in the defoaming tank 5 is sucked by the vacuum suction device 16 through the vacuum pipe 7. . Then, after the vacuum state is reached, the embedding agent is injected into the container 3 from the injection port 13a of the container 13 by the metering supply pump, and a predetermined amount of embedding is made while the embedding agent sufficiently enters the fiber bundle F. Fill each container 3 with the packaging.

In this case, the vacuum state may be a degree of vacuum that can be achieved by a normal vacuum suction device 16, and the degree of vacuum is not particularly limited, but a degree of vacuum of about 10 to 300 Torr is preferable, for example. This is because, in the case of less than 10 Torr, evaporates rapidly because it uses water as Umatsutsumizai not preferable because it is necessary to extra use for evaporation of water. On the other hand, if it exceeds 300 Torr, the bubbles inside the fiber bundle cannot be sufficiently removed, which is not preferable.

  However, in the present invention, since the embedding agent 12 is still in a liquid state at the time of completion of defoaming, it is necessary to fix the single fiber group with the embedding material by solidifying by changing the phase to the solid state. It is. Therefore, the defoaming tank 15 that has been defoamed is opened to the atmosphere, and in this state, the container group 3 in the defoaming tank 15 is cooled to solidify the embedding agent 12 to obtain a solid embedding material.

  In addition, after putting the fiber bundle F into the defoaming tank 15 in the defoaming step 15 in the defoaming step, the air in the defoaming tank 15 is vacuum-sucked to expel the air from the inside of the container group 13. A method of injecting an embedding agent into the container group 13 was adopted. However, aside from such a method, there is a method in which the container group 13 is first filled with the embedding agent 12, the container group 13 filled with the embedding agent 12 is placed in the defoaming tank 15, and vacuum suction is performed. It can also be adopted. At this time, when it is necessary to thoroughly remove bubbles, the inside of the cooling tank 15 can be cooled while the inside of the cooling tank 5 is in a vacuum state, and the embedding agent 12 can be solidified. On the contrary, it is also a preferable aspect to pressurize and degas bubbles in the embedding agent 12 by pressurizing to a high pressure, contrary to vacuuming the inside of the defoaming tank 15. Furthermore, it is also a preferred embodiment that a surfactant having an affinity for fibers and having an antifoaming property is mixed in the embedding agent 12 and used together with the above-described method.

  Further, as a surfactant to be mixed in the embedding agent 12, a surfactant contained in a laundry detergent for clothing will be described as an example. This surfactant surrounds oil and dirt components adhering to the clothing fabric. Furthermore, it penetrates into the gaps between the fiber and the oil and dirt components, and finally plays a role of removing the oil and dirt from the fiber. Therefore, if such a surfactant is mixed with the embedding agent 12 and used, the embedding agent 12 can be satisfactorily penetrated into the gaps of the single fiber group. Then, the embedding agent 12 penetrates into the minute gaps between the single fiber groups, the embedding agent 12 wets the single fiber groups, and even if the minute air remaining between the single fiber groups still exists, the interface The embedding agent surrounds the minute air by the action of the active agent, and the remaining minute air can be isolated and removed. In addition, since the embedding agent has an affinity with the single fiber group, it can perform better embedding processing.

  Examples of the surfactant having such a function include nonionic surfactants such as polyalkylene glycol esters and ethers, anionic surfactants such as fatty acid, alkyl phosphate, sulfonate, and sulfate alkali metal salts, and quaternary ammonium. Examples thereof include cationic surfactants such as salts, and amphoteric surfactants such as alkali metal salts of aminocarboxylic acids and alkylbetaines.

  In the present invention, it is also a preferable aspect that the embedding agent 12 is once boiled before the embedding treatment is performed, and the gas components dissolved in the embedding agent 12 are expelled. This is because it is possible to prevent the air dissolved in the embedding agent 12 from being generated for some reason during the embedding process. Therefore, bubbles generated in the fiber bundle F can be suppressed, and the binding force of the single fiber group by the solidified embedding material can be enhanced.

  Furthermore, when the embedding agent 12 is changed into a solid state and returned to the embedding material, a sufficient time is required to suppress the generation of bubbles in the fiber bundle F during this step, for example, Preferably, the embedding agent 12 is gradually phase-changed and solidified over a long period of 8 to 48 hours. For less than 8 hours, since the embedding agent 12 is solidified before the bubbles inside the fiber bundle F are removed, the bubbles remain in the fiber bundle F, which is not preferable. On the other hand, if it exceeds 48 hours, it takes too much time to produce the fiber bundle F, which is not preferable from the viewpoint of production efficiency. As a means for adjusting the time until the embedding agent 12 is solidified, a method for adjusting the cooling temperature and a method for automatically reducing the cooling temperature stepwise can be appropriately selected.

  Next, there are conditions that must be taken into account in the icing process in which the fiber bundle F is frozen with water. Therefore, this point will be described in detail with reference to FIG. 13 showing an embodiment of an icing treatment apparatus for icing treatment. However, FIG. 13 is a schematic configuration diagram illustrating the apparatus configuration in order to schematically explain the icing treatment method and the icing processing apparatus of the present invention, and a part of the cross section is given.

  In FIG. 13, an icing treatment apparatus according to the present invention includes 21 a refrigeration apparatus, 22 an icing container, 23 a fixture, 24 a decompression chamber, 25 a gas-liquid separator, 26 an exhaust apparatus, 27 a heating apparatus, Reference numeral 28 denotes a fine vibration generating device, and 29 includes a control device. In FIG. 13, a portion surrounded by a two-dot chain line is a refrigeration apparatus 21 configured by a freezer, for example, and is water (embedding agent) in which a fiber bundle F that is stationary in an icing container 22 is immersed. In this way, the fiber bundle F is frozen (embedded) by ice (embedding material). The refrigeration apparatus 21 is not limited to the illustrated freezer, and may be a system in which the icing container 22 is immersed in a refrigerant bath.

  Here, the fiber bundle F is formed by fixing both ends of the fiber bundle F while maintaining the aligned state, and then cutting both ends on the outside of the fixture 23. Then, the fiber bundle F is left in a state where it is suspended in an icing container 22 filled with water that has been separately deaerated while being fixed by the fixture 23.

  At this time, a decompression chamber 24 that also serves as a lid member for the freezing container 22 is provided on the freezing container 22. Further, a heating device 27 for heating the decompression chamber 24 is attached to the outer periphery of the decompression chamber 24 during the freezing process. The heating device 27 is provided for delaying icing from the water surface formed by water filled in the icing vessel 22. That is, the role of the heating device 27 is that the density of water used for the freezing treatment is maximum at 4 ° C., so that the water at 0 ° C. is pushed by the lid member portion of the upper freezing container 22, Plays a role in preventing freezing from the formed water surface.

This is because if the water surface formed on the lid member portion of the freezing container 22 freezes, the air dissolved in the water underneath has a concentration of air dissolved in the water as ice is formed on the water surface. This is because it increases and eventually bubbles into water. In addition, the bubbled air is confined inside the escape space by the ice already generated upward. However, by heating the lid member portion of the icing container 22 by the heating device 27, icing of the water surface formed on the lid member portion is prevented. Then, the bubbled air can be easily released from the water surface that is not frozen. It should be noted that when the water in the freezing container 22 freezes, the air dissolved in the water is bubbled, although the water has an air solubility of 2.78 × 10 ⁻² at 0 ° C. in the atmosphere. This is because the solubility of air in ice in which water has been frozen is zero, so that air dissolved in water will exist as a gas in ice as water freezes.

  At this time, since the above-described lid member portion also serves as the decompression chamber 24, the air bubbled from the decompression chamber 24 is exhausted by the exhaust device 26. Then, when the entire water in the freezing container 22 has been frozen, the bubbled air does not remain in the ice. In addition, since the heating device 27 plays such an important role, it is preferable to control the heating temperature and the heating time so that the heating temperature and the heating time can be arbitrarily set. Therefore, a control device 29 for controlling the heating temperature is provided as means for realizing this.

  At this time, it is preferable to determine the heating temperature and the heating time by the heating device 27 by an experiment or the like. This is because there is no significance in operating the heating device 27 after the freezing of the entire water filled in the freezing vessel 22 by the freezing device 21 is completed. On the contrary, the continuous use of the refrigeration apparatus 21 is also required, which is disadvantageous in terms of running costs. In addition, in the manufacturing process of a very short fiber, both ends of the fiber bundle subjected to freezing are cut off by a cutter. For this reason, there is not much significance in continuing the refrigeration operation until the entire water filled in the freezing container 22 completes freezing. Therefore, if the freezing process for the fiber bundle F has already been completed up to the portion cut by the cutter, it is no longer necessary to continue the freezing process for the fiber bundle F any more.

  At this time, a gas-liquid separator 25 for separating gas and liquid is attached to the rear side of the decompression chamber 24. In such a state, it is preferable that the air present in the decompression chamber 24 on the water surface is exhausted under a weak negative pressure of 30 Torr to 650 Torr by the exhaust device 26 including a vacuum pump and a wind exhauster through the exhaust pipe. . Here, it is preferable to place the degree of decompression inside the decompression chamber 24 under the weak negative pressure as described above. To make the degree of decompression too large, evaporation of water filled in the ice container 22 is reduced. This is because it is not a good idea because it promotes more than necessary and increases the equipment cost and operation cost for constructing equipment having such a capability. On the other hand, if the degree of decompression is too low, the effect of expelling air bubbled into water during the icing process is reduced, which is not preferable.

  In this way, moisture is removed from the air containing water droplets sucked and exhausted from the decompression chamber 24, and only the air is exhausted from the exhaust pipe through the exhaust device 26 to the outside of the system. Accordingly, the bubbles generated in the deaerated water of the fiber bundle F filled with separately deaerated water filled in the ice container 22 or the fibers when the fiber bundle F is allowed to stand in the ice container 22. The gas brought in with the bundle F is continuously or intermittently sucked and exhausted during the freezing process.

  According to the apparatus described above, since the suction and exhaust can be efficiently performed continuously during the freezing process (embedding process), the air bubbled during the freezing process can be exhausted well. However, along with such operations, air dissolved in water in the freezing container 22 is actively bubbled, and this is combined to grow to increase buoyancy, and is maintained in an unfrozen state by heating. In order to facilitate escape from the water surface, it is preferable to slightly vibrate the icing container 22. Moreover, the air adhering to the fiber bundle F can be peeled off from the fiber bundle surface by slightly vibrating the fiber bundle F and water, which is also extremely effective in this respect. It should be noted that “micro-vibration” referred to in the present invention includes “ultra-sonic vibration” in which an ultrasonic wave is applied to vibrate.

  Therefore, in order to generate such a slight vibration, a minute vibration generator 28 that can be easily attached to and detached from the frozen container 22 is attached to an arbitrary position on the side surface or the lower surface of the frozen container 22. By 28, the entire freezing container 22 is given a slight vibration. In addition, as such a fine vibration generator 28, well-known fine vibration generators, such as an electromechanical vibrator and an acoustic vibrator, can be used. At that time, the vibration frequency and amplitude generated by the fine vibration generator need to be changed depending on conditions such as the size and shape of the ice container 22 or the total fineness of the fiber bundle F. It is preferable that the setting can be arbitrarily changed to the value of.

The fiber bundle F is subjected to freezing treatment with the fine vibration generator 28 attached to the freezing vessel 22 as described above. The density of water at 0 ° C. is 0.9998 g / cm ³ , whereas The density of ice at 0 ° C. is 0.917 g / cm ³ . Therefore, it is necessary to consider that the volume of about 10% expands when water becomes ice. For this reason, when the water in the ice container 22 having a constant volume freezes, defects such as cracks and cracks due to internal stress accompanying the volume expansion of ice may occur. If defects such as cracks and cracks occur in the frozen ice, the end face of the fiber bundle F that has undergone icing is cut into a thin piece to produce excellent short fibers having a fiber length of 0.1 mm or less. It becomes an obstacle.

  By the way, since the freezing container 22 is installed in the refrigeration apparatus 21, the internal water begins to freeze from the wall surface side of the freezing container 22, but the lid member is heated by the heating device 27 as described above. Therefore, this part of water will freeze at the end. Accordingly, the growth of ice gradually occurs from the bottom wall surface side of the freezing container 22, and the microvibration is imparted to the unfrozen water, so that the freezing of the water in the freezing container 22 Except, it progresses from the bottom part and the side part of the ice container 22 to the upper part where the lid member exists.

  On the other hand, when the apparatus of the present invention is not used, icing starts from the upper part including the water surface and the wall surface of the icing container 22 so as to surround the unfrozen water, and the icing gradually progresses toward the inside. To do. For this reason, when freezing of unfrozen water confined in the interior starts, defects such as cracks and cracks occur due to internal stress accompanying the volume expansion of the ice at this time. However, in the present invention, for the reasons described above, unfrozen water can freely move upward during freezing. For this reason, the internal stress accompanying volume expansion at the time of the phase change of water to ice is reduced, and it is possible to prevent the occurrence of defects such as cracks and cracks.

  Naturally, freezing treatment of the water in the freezing container 22 in this manner is also extremely effective in eliminating bubbles in the ice that is the embedding material. This is because bubbles in ice, which is the embedding material, are frozen by finally freezing the water containing the bubbled air while bubbling the air dissolved in the water that freezes into unfrozen water. It is because it can be eliminated. For this reason, dissolved gas does not freeze in the vicinity of the fiber bundle F, and this is cut with a cutting blade, for example, an ultrashort fiber having a fiber length of 0.1 mm or less is miscut. Therefore, mass production can be performed with good yield.

  As described above, in the present invention, the water in the freezing vessel 22 is given a slight vibration or 50 revolutions per minute with a constant temperature gradient between the upper and lower sides of the freezing vessel 22. It is a preferred embodiment to freeze with stirring. At this time, for example, the temperature of the bottom part and the side part of the freezing container 22 is cooled to −1 ° C. to −20 ° C., and the temperature of the upper part (lid member part) of the freezing container 22 is heated to 0 ° C. to 5 ° C. It is preferable. As a result, the bottom and side portions of the freezing container 22 are kept at a predetermined low temperature, and the top is kept at a predetermined high temperature. As a result, water freezes upward from the bottom of the freezing container 22, The converted air is not trapped in the ice container 22.

  At that time, if the water in the icing container 22 is vibrated by the fine vibration generator 28 or the like, the unfrozen water is always moved. For this reason, bubbles that are about to be trapped by the ice that has started to freeze are repelled and returned to the unfrozen water. And finally, the fiber bundle F embedded by the bubble-free and transparent ice is completed. The temperature gradient described above will be described. The temperature for cooling the bottom of the freezing vessel 22 is set to -1 ° C to -20 ° C (preferably -2 ° C to -5 ° C). This is because the gradient becomes too gentle and icing does not occur from the bottom of the icing vessel 22. Further, the decompression chamber 24 also serving as a lid member is heated so that the water temperature in this portion is 0 ° C. to 5 ° C. (preferably 0 ° C. to 2 ° C.). It begins to freeze from the upper part of the air bubbles, and the bubbles are trapped and cannot escape to the upper part.

In the present invention, it is also a great feature that the ultrashort fiber and the embedding material can be easily and completely separated after cutting when the ultrashort fiber is manufactured. Therefore, in order to separate them easily and completely, ice is used as an embedding material . Note that lever to use the ice as Umatsutsumizai, as described above, can be easily frozen fiber bundles using a simple device.

When ice is used as an embedding material, it is heated to a temperature higher than 0 ° C. and returned to water, and then passed through a drying process, so that the ultrashort fibers and the embedding material can be easily and easily Can be separated. Thus, since in the present invention, using ice as the embedding material, may be used heat drying, or drying at room temperature.

  However, when heat drying or room temperature drying is performed, dimensional changes and quality deterioration occur, particularly when the drying temperature is increased, or extremely short fibers are produced from composite fibers in which two or more thermoplastic resins are bonded together. It becomes more prominent in some cases. In particular, care should be taken when drying optical interference fibers as described in JP-A-11-241223. Because this type of fiber, the thickness of the polymer layers that are alternately laminated so that the incident light interferes with the alternately laminated polymer and presents a vibrant color corresponds to the wavelength of the incident light. This is because it is controlled on the micron order. Therefore, in such a case, it is preferable to use a freeze-drying method that can remove moisture while still in a frozen state. Therefore, in such a composite fiber, the above-mentioned heat drying and room temperature drying can be performed as means for drying and removing moisture remaining in the state of being attached to the ultrashort fiber after cutting, but freeze drying Is preferably used.

  In the present invention, freeze-drying that can be dried at a low temperature can be used for the purpose of preventing the dimensional change and quality deterioration. Because it is a drying method that sublimates and removes moisture as water vapor from the ice state without returning the ice adhering to the surface of ultrashort fibers to water by adopting freeze drying, during freeze drying This is because there is no need to heat the ultrashort fiber and it can be maintained at a low temperature. Therefore, drying can be performed without causing the above-described problems. Therefore, when water (ice) is used as an embedding agent (embedding material), it is extremely convenient to dry the water by freeze drying. That's it.

  Here, considering conditions favorable for freeze-drying, it is needless to say that the larger the surface area of the raw material subjected to freeze-drying, the more preferable it is for water vapor to be sublimated efficiently. In this regard, in the method for producing ultrashort fibers according to the present invention, since the end faces of the fiber bundles frozen by the cutting blade are cut into flakes, the cutting surfaces newly appear one after another. At the time of manufacture, it can be said that the surface area is very large. However, if such an aggregate of cut ultrashort fibers in a state suitable for freeze-drying is left in an accumulated state without taking any measures, newly generated cutting surfaces will overlap each other. However, the surface area is reduced despite the fact that much surface area is generated.

  Therefore, the advantage of a large surface area newly generated by cutting is utilized to the maximum extent. Therefore, in the present invention, it is preferable to form an aggregate in which manufactured ultrashort fibers are accumulated by interposing air between flaky iced short fibers. As a result, the aggregate composed of the cut freezing short fibers is sequentially accumulated in a flake-like state like so-called “oyster ice”. For this reason, a space in which air is interposed is formed between the accumulations in which ultrashort fibers and ice are mixed, and a porous aggregate is obtained. At that time, if the temperature is kept at a temperature at which the ice does not melt (a temperature lower than the melting point of the ice), the porous state is maintained as it is. Thus, if the raw material having such a porous state is subjected to freeze-drying, a large dry surface area can be obtained, so that an advantage of a high drying speed is produced.

  In addition, when carrying out this freeze-drying, it is important to keep the ice embedded in the cutting process so that it does not return to water. Therefore, for this reason, it is not preferable to accumulate the extremely short fibers frozen in a condition that the ice adhering to the obtained ultrashort fibers melts. That is, if it is kept at a temperature at which ice melts and becomes water, it needs to be dried by a freeze-drying method, so it is necessary to freeze the melted water again, and energy is wasted. In addition, in this case, the surroundings of the very short fibers are frozen in a state where they are embedded with water. For this reason, the porous state as described above cannot be created. Therefore, it is difficult to increase the drying speed, and it takes a lot of time to remove moisture by freeze-drying.

  For the reasons described above, in the present invention, in the process of accumulating the cut icing short fibers, the icing short fibers are soft-landed while blowing air cooled to below zero degrees, thereby cutting the cut icing poles. It is a preferred embodiment to form a bridge between short fibers and accumulate them. In addition, at that time, it is needless to say that the accumulated thickness of the frozen short fiber aggregates needs to be adjusted so that the bridge formed by the dead weight of the accumulated frozen short fibers is not broken. For this purpose, it is preferable to use a method such as traversing the storage means of the frozen short fibers so that the accumulated thickness of the cut frozen short fibers is substantially uniform. Furthermore, in order to simplify and simplify the drying process, it is preferable to subject the icing short fibers to lyophilization while being accommodated in the accommodating means. Therefore, in such a case, a fine opening is formed on the contact surface where the storage means and the cut freezing short fiber are in contact with each other so that the ice can also be sublimated as water vapor from here. Is preferred.

  The present invention is characterized in that ultrashort fibers are produced by cutting a cutting agent made of an embedded fiber bundle into a thin piece instead of cutting the fiber bundle F. Therefore, an embodiment according to a cutting apparatus that cuts and manufactures ultrashort fibers from an embedded fiber bundle will be described with reference to the drawings.

  FIG. 14 is a schematic apparatus configuration diagram schematically illustrating an ultrashort fiber manufacturing apparatus according to the present invention, in which 31 is a material to be cut (a fiber bundle subjected to embedding processing, which is a cutting object), and 32 is a holding member. Means 33 is a tool post, 34 is a cutting blade, 35 is a contact pressure applying means, 36 is a driving means, 37 is a protrusion length adjusting means (not shown in FIG. 14), 38 is a means for collecting very short fibers, and , 39 respectively indicate a frame. Reference symbol A indicates a contact plane of the tool post 33 that presses the cutting end surface of the workpiece 31 with a predetermined contact pressure. Since this contact plane A serves as a cutting reference surface, sufficient smoothness is obtained. It must be formed with flatness. However, although the illustration of the cooling means and / or the cooling means included in the holding means 32 is omitted in FIG. 13, these will be described later. Further, the ultrashort fiber collecting means collects the cut ultrashort fiber, and is, for example, a collection bag or a cylindrical container so as to surround the outer periphery of the rotating tool post 33. Is provided.

  Here, the contact pressure applying means 35 plays a role of pressing the work material against the contact plane A of the tool post 33 with a predetermined force. As shown in the drawing, the contact pressure generating device 35a, the connecting rod member 35b, A contact pressure transmission member 35c to the cutting material and a fixing member 35d are included, and are positioned and fixed to the gantry 39 (39c) via the fixing member 35d. An example of the contact pressure applying means 35 is a fluid pressure operating cylinder that operates at a fluid pressure such as the pressure of compressed air or oil pressure as illustrated. However, the present invention does not have to be limited to the embodiment illustrated in FIG. 14, and any device that can be pressed against the contact plane A of the tool post 33 of the work material 31 with a predetermined contact pressure is applicable. Can be preferably used. For example, as a known conveyance device capable of continuous or intermittent feeding, a device for conveying the material to be cut 31 by a pair of belts or rolls can be used.

  In the example of FIG. 14, the driving means 36 is constituted by a rotational driving means for rotationally driving the tool post 33, a driving device 36a such as a hydraulic motor or an electric motor serving as a power supply source, and driving-side power. It includes a transmission member 36b, a power transmission member 36c, a driven power transmission member 36d, a rotation drive shaft 36e, a bearing 36f, and a fixing member 36g of the bearing 36f. The driving device 36a and the fixing member 36g are respectively positioned and fixed on the gantry 39b. A driven-side power transmission member 36d is fixed to one end of the rotary drive shaft 36e, and a tool post 33 is fixed to the other end, and is further rotatably supported by a bearing 36f at an intermediate portion thereof. .

  Therefore, when the power from the drive device 36a is transmitted as a rotational force to the rotational drive shaft 36e via the drive-side power transmission member 36b, the power propagation member 36c, and the driven-side power transmission member 36d, the rotational drive shaft A tool post 33 fixed to the other end of 36e is rotationally driven. As specific examples of the power transmission members 36b and 36d, a toothed pulley, a pulley for a V-belt, a gear, and the like can be exemplified, and the power transmission member 36c is a toothed belt (timing belt). , V belts, chains, intermediate gears and the like.

  At this time, a cutting blade 34 (cutting blades 34a and 34b are clearly shown in the drawing) for cutting the workpiece 31 to obtain ultrashort fibers is directed to the tool post 33 from the center of rotation toward the radial direction. Since at least one piece is provided radially, when the cutting blade 34 is rotationally driven together with the tool post 33, the workpiece 31 that comes into contact with the tool post 33 is cut by the cutting blade 34. At this time, it is preferable that the number of rotations of the tool post 33 can be changed in accordance with the properties of the workpiece 31, for example, 0.05 to 1,500 rotations per minute. Such a change in the number of revolutions is, for example, as is well known in the art. For example, the drive device 36a is used as an AC motor such as an induction motor or a synchronous motor, the frequency is controlled by an inverter, or the number of pulses supplied as a pulse motor is used as the drive device 36a. Or by providing a driver device that controls the frequency by chopping a direct current using the drive device 36a as a direct current motor.

The embodiment described in detail above relates to an apparatus for obtaining ultrashort fibers by rotating the cutting blade 34 and bringing the workpiece 31 into contact with the cutting blade 34, but conversely, the cutting blade 34. May be fixed, and the workpiece 31 may be rotated and brought into contact with the cutting blade 34 to cut ultrashort fibers. Further, instead of the rotational movement of the cutting blade 34 or the workpiece 31, the cutting blade 34 or the workpiece 31 may be reciprocated linearly. What is important here is to move the workpiece 31 including the fiber bundle 31a and the cutting blade 34 relative to each other in the cutting direction, thereby cutting the cut end surface of the fiber bundle 31a into a thin piece.
The present invention is characterized in that the material to be cut 31 is cut to produce ultrashort fibers. The “cutting embodiment” will be described in more detail with reference to FIG.

  FIG. 15 shows a schematic front sectional view in which the cross section of the main part (cutting part) in FIG. 14 is enlarged. In FIG. 15, the material to be cut 31 is the fiber bundle 31a as already described in the embedding material 31b. It has been embedded. At this time, the fiber bundle 31a is composed of a large number of single fiber groups that are aligned, and the total fineness of the fiber bundle 31a is 10,000 to 10,000,000 dtex. Further, the total length of the fiber bundle 31a used at this time is not particularly limited, but is preferably 5 to 1000 mm in consideration of workability and productivity, and further considering the ease of embedding processing. However, in the embodiment of FIG. 15, the fiber bundle 31 a cut to a predetermined length is embedded in a separate process different from the cutting process by the embedding material 31 b and is cut in a batch process. It is also possible to continuously embed a fiber bundle 31a composed of a group of single fibers to be embedded with an embedding material 31b and cut it continuously.

  Note that in FIG. 15, the embedding material 31b existing inside the fiber bundle 31a is not shown in FIG. 15, but as already described in detail for the embedding process, Needless to say, the embedding material 31b is also present in the interior. In particular, as the total fineness of the fiber bundle 31a increases, the single fiber group constituting the fiber bundle 31a moves in the direction in which the cutting blade 34a moves at the time of cutting (the direction of the white arrow shown in FIG. 15). In order to prevent escape from the blade 34a, it is necessary to constrain the degree of freedom of movement by the embedding material 31b.

  Further, as illustrated in FIG. 15, the cutting blade 34 provided on the tool post 33 is adjusted so as to be protruded by a protruding length C from the contact plane A of the tool post 33. For example, the protrusion length C is adjustable to a height of 0.001 to 0.1 mm. Then, a state where the cutting end surface of the workpiece 31 is constantly pressed against the contact plane A of the tool post 33 with a predetermined contact pressure by the contact pressure transmitting member 35c constituting a part of the contact pressure applying means 35 appears. Is done. Therefore, when the cutting blade 34 provided on the tool post 33 is rotated, ultrashort fibers having a fiber length of 0.005 mm or more and 0.1 mm or less corresponding to the adjusted protrusion length C are cut from the workpiece 31. It becomes possible to do. In addition, although the thickness of the cutting blade 34 to be used is a design matter that should be appropriately optimized in accordance with the properties of the material 31 to be cut, a thickness of 0.2 to 12.0 mm can be suitably used.

  Here, if the supplementary explanation is given with reference to the embodiment illustrated in FIG. 16 regarding the adjustment of the protrusion length C of the cutting blade 34, the protrusion length C can be adjusted by the protrusion length adjusting means 37. In FIG. 16, the protrusion length adjusting means 37 includes a sliding member 37a to which a cutting blade 34 is fixed and a fastening member 37b such as a hexagon socket bolt, as shown in FIG. 37a and 37b are attached to the opening O provided in the tool post 33 as illustrated. In FIG. 16, F is a sliding surface formed in the opening O of the tool post 33 on which the main body member 37a slides. H is an elongated hole for allowing the sliding member 37a to move in the sliding direction when the fastening member 37b is loosened. G is a groove into which the bottom of the sliding member 37a is fitted. This groove is provided at the illustrated position of the opening O of the tool post 33 along the sliding direction of the sliding member 37a.

  Since the protrusion length adjusting means 37 of the present invention is configured as in the embodiment of FIG. 16, when a fastening member 37b such as a hexagon socket head bolt is loosened using a tool such as a hexagon wrench, The sliding member 37 a is slidable in the protruding direction of the cutting blade 34 while being guided and regulated by the groove G. Then, when the fastening member 37b is tightened in a state where the protruding length is maintained at the predetermined length C using a jig or the like, the cutting blade 34 can be adjusted to the predetermined protruding length C. In FIG. 16, at least one cutting blade 34 is provided so as to extend in the direction perpendicular to the paper surface of the tool post 33, that is, in the radial direction from the rotation center (the axis of the rotation drive shaft 36e). This has already been described.

As described above, it is possible to obtain ultrashort fibers by cutting the workpiece 31 using the ultrashort fiber manufacturing apparatus of the present invention. When cutting, if the working environment for cutting is higher than the solidification temperature of the embedding material 31b, the embedding material 31b is liquefied and cannot play its role. For this reason, the holding means 32 for holding the work material 31 is provided with a cooling means (not shown), or when the cooling means alone cannot cope with it, a cooling means (not shown) is provided to embed the material 31b. There it is necessary to be well kept cool to prevent liquefaction. Moreover, in order to achieve the said objective, it is also a preferable aspect that the circumference | surroundings of the to-be-cut material 31 are cooled locally, or the whole cutting device is cooled.

As described above, during the cutting of the workpiece 31, it is preferable that the present invention includes a cooling means for cooling the workpiece 31. Then, even in the case of performing the cutting at so that temperature conditions in which the Umatsutsumizai 31b is turn into liquid, cooling the object to be cut material 31 to a suitable temperature by the cooling means, Umatsutsumizai 31b Can maintain a solid state that does not cause a phase change.

  Hereinafter, an embodiment according to an ultrashort fiber manufacturing apparatus provided with the cooling means will be described in detail with reference to FIG.

  FIG. 17 is a schematic device configuration diagram schematically illustrated to describe an embodiment of an ultrashort fiber manufacturing device according to the present invention. In this figure, 61 (61a and 61b) is a refrigerant pipe, 62 (62a and 62b) is a temperature sensor, 63 (63a and 63b) is a signal line, and 64 is a refrigerator unit. The apparatus including the refrigerant pipe 61, the temperature sensor 62, the signal line 63, the refrigerator unit 64, and a temperature control means (not shown) constitutes the cooling means of the present invention.

  Here, the embodiment of the cooling means of the present invention illustrated in FIG. 17 will be described. The cooling means includes, for example, a refrigerator unit 64. The refrigerator unit 64 further includes a compressor, a condenser, A series of refrigeration equipment such as an expansion valve is provided as a component. Therefore, the refrigerant is circulated and circulated through the refrigerant pipes 61a and 61b through the refrigerant pipes 61a and 61b, and chlorofluorocarbon, alternative chlorofluorocarbon, isobutane, ammonia, ethylene glycol, alcohol, etc. are respectively circulated through the refrigerant pipes 61a and 61b. The cutting material 31 and the cutting blade 34 can be cooled to the required cooling temperature.

  In this cooling, the low-temperature vaporized gas can be adiabatically expanded and cooled, and the cooled low-temperature vaporized gas can be directly circulated through the refrigerant pipe 61 with the refrigerant. Further, when it is not necessary to cool to such a low temperature, the refrigerant such as brine is primarily cooled by the cooled low-temperature vaporized gas, and the refrigerant such as the first cooled brine is supplied to the refrigerant pipe 61. The material to be cut 31 and / or the cutting blade 34 may be secondarily cooled by circulation. Conversely, when the workpiece 31 is further cooled to a lower freezing temperature, for example, a well-known liquefied gas such as liquid nitrogen or liquid oxygen is generated by a standard method, and this is used as a refrigerant into the refrigerant pipe 61. It can also be made to circulate.

  In the embodiment of FIG. 17, a method of cooling by holding the holding means 32 holding the workpiece 31 and the cutting blade 34 in contact with the refrigerant pipes 61 a and 61 b is illustrated, but of course, for example, the holding means 32. For example, a jacket may be provided on the outer side of the coolant to circulate and circulate the coolant through the jacket. Furthermore, although the apparatus is larger, a freezing chamber in which the internal atmosphere is cooled to an optimum temperature is provided, and the entire cutting apparatus including the work material 31 and the cutting blade 34 is cooled in the freezing chamber. Alternatively, only a portion necessary for cooling may be locally cooled.

  As described above, in the present invention, the workpiece 31 is cooled by the cooling means, but it is preferable to cool not only the workpiece 31 but also the cutting blade 34 at the same time as described above. This is because if the workpiece 31 is continuously cut for a long time, if the temperature of the cutting blade 34 rises due to friction with the workpiece 31 or the like, the cutting blade 34 may become dull or cut. The wear of the blade 34 becomes remarkable, or the fiber length of the cut ultrashort fiber is changed during the cutting due to the change of the protruding length of the cutting blade due to the influence of thermal expansion or the like. Because it is influenced by.

  At this time, when a relatively low molecular weight resin or paraffin having a melting temperature of 10 to 150 ° C. is used as the embedding material 31b, the embedding material 31b is soft, so the fiber bundle 31a is embedded in the embedding material 31b. May cause a situation where it cannot be firmly fixed and restrained. Even in such a case, the hardness of the embedding material 31b can be controlled by cooling the work material 31 by the cooling means and freezing it to 0 to −100 ° C., for example. Then, by controlling the hardness of the embedding material 31b, it is possible to reveal a situation in which the degree of freedom of movement of the fiber bundle 31a can be suitably restricted by the embedding material 31b. In this case, the temperature suitable for freezing the work material 31 varies depending on the embedding material 31b to be used. It is preferable to determine.

  The cooling temperature determined by the experiment in this manner is stored in the storage means of the temperature control means constituted by a microcomputer (not shown), and the workpiece 31 and the cutting blade 34 are cooled to an optimum state. Used to do. Regarding temperature control, for example, a temperature sensor 62a having a temperature detection end such as a thermocouple attached to a gripping member 14 that grips the workpiece 31, or a cutting blade 34 or a fixing member for fixing the same. The temperature of the work material 31 and the cutting blade 34 is detected by the same temperature sensor 62b attached to 5 respectively, and a transducer or an A / D converter (analog / digital) is sent to the temperature control means using the detected temperatures as control variables. The data is input via an interface means including a converter. Based on the input detected temperature, the refrigerator unit is feedback-controlled according to a standard method so that the work material 31 and the cutting blade 34 maintain the optimum temperature determined by the experiment as described above. That's fine.

  However, the cooling means used in the present invention is not limited to the system using the refrigerant as described above, and other systems can also be used. For example, as such another method, a cooling method in which cooling is performed using a Peltier element schematically illustrated in FIG. 18 may be employed. In FIG. 18, 65 is a Peltier element, 66 is a heat sink, 67 is electrical wiring of the Peltier element, and 68 is a heat insulating material. Here, the Peltier element 65 will be briefly described. The Peltier element 65 is an element that utilizes a so-called “Peltier effect”, and converts electric power into heat energy by passing a current between the elements, and changes the temperature. In general, the p-type thermoelectric conversion element and the n-type thermoelectric conversion element are alternately connected by electrodes, and the electrode surface is sandwiched by an insulating substrate. It has the advantage that its structure is simple and easy to handle.

  The cooling temperature determined by the experiment in this manner is stored in the storage means of the temperature control means constituted by a microcomputer (not shown), and the workpiece 31 and the cutting blade 34 are cooled to an optimum state. Used to do. Regarding temperature control, for example, a temperature sensor 62a having a temperature detection end such as a thermocouple attached to a gripping member 14 for gripping the workpiece 31, or a cutting blade 34 or a fixing member for fixing the same. The temperature of the workpiece 31 and the cutting blade 4 is detected by the same temperature sensor 62b attached to 5 respectively, and a transducer or an A / D converter (analog / digital) is sent to the temperature control means using the detected temperature as a control variable. The data is input through interface means including a converter. Based on the input detected temperature, the refrigerator unit is feedback-controlled according to a standard method so that the work material 31 and the cutting blade 34 maintain the optimum temperature determined by the experiment as described above. That's fine.

  In addition, the shape of the workpiece 31 held by the holding means 32 is not limited to a round bar shape, but may be any shape such as a square column shape, a hexagonal column shape, an elliptical column shape, or a column shape whose cross section has a donut shape. can do. Such a shape is obtained by injecting the fiber bundle 31a and water, which are arranged in a pot (freezing container), for example, into conditions for embedding the fiber bundle 31a with the embedding material 31b. In the case of embedding and freezing, the shape of the work material 31 depends on the shape of the pot. Further, it varies depending on the condition of the gripping member 32 a of the holding means 32 that holds the workpiece 31.

  The apparatus for producing ultrashort fibers according to the present invention is the above-described embodiment, that is, the cutting end surface of the workpiece 31 is continuously applied to the contact plane A formed on the upper surface of the tool post 33 with a predetermined contact pressure. In addition to the embodiment of pressing and cutting with the cutting blade 34a, the following embodiments may be employed.

  In the embodiment described below, the fiber length to be cut on the workpiece 31 without pressing the cutting end surface of the workpiece 31 with a predetermined contact pressure against the contact plane A formed on the upper surface of the tool post 33. A predetermined amount corresponding to is forcibly supplied to the cutting blade 34a and is cut by the cutting blade 34a. Then, after the cutting end surface of the workpiece 31 is cut by the cutting blade 34a and before the next cutting starts, a predetermined amount corresponding to the fiber length to be cut of the workpiece 31 is applied to the cutting blade 34a. Then, the procedure of forcibly supplying again and cutting with the cutting blade 34a is repeated. Therefore, in this case, the apparatus of the present invention supplies the workpiece 31 with a predetermined amount intermittently to the cutting blade 4a by an amount corresponding to the fiber length to be cut as a means for performing the above-described function. Supply means are provided.

  As a specific configuration of such a supply means, a well-known technique commonly used in a cutting machine tool to supply a predetermined amount of the cutting blade 34a and / or the workpiece 31 is employed. Can do. Therefore, detailed description thereof is omitted here. However, if an example is given, the holding tool which hold | grips the workpiece 31 reliably without slipping is provided. And this holding tool is attached to the shaft in which the spiral feed groove was screwed. A known intermittent feeding means for intermittently supplying the workpiece 31 to the cutting blade 34a by a predetermined amount by rotating the shaft by a predetermined rotation angle can be exemplified. At this time, in order to rotate the shaft by a predetermined rotation angle, a servo motor such as a pulse motor may be used.

  In the embodiment described above, the cutting end surface of the workpiece 31 is not constantly brought into contact with the contact plane A of the tool post 33, and the cutting end surface is brought into contact with the cutting blade 4a only during cutting. There is an advantage that the cutting end surface of the cutting material 31 is not easily affected by friction or vibration of the tool post 33 or the cutting blade 34a generated during cutting.

  The present invention is intended to provide a method for satisfactorily producing ultrashort fibers by cutting while increasing production efficiency. The embodiment will be described in detail below with reference to FIGS. 19 and 20. Explained. FIG. 19 and FIG. 20 are schematic explanatory views exemplified for explaining the production of ultrashort fibers according to the present invention.

Here, when the workpiece 31 is cut out from the fiber bundle 31a as ultrashort fibers of 0.005 to 0.1 mm, the workpiece 31 is held by the holding means 32 at a position close to the cutting blade 34. However, it is preferable to perform cutting. By doing so, the embedding material 31b is easily deformed by an impact force at the time of cutting, such as ice or dry ice, or the force acting at the time of cutting is concentrated on the fixed portion against a material that is easily damaged. Can be avoided. Therefore, the holding means 32 that plays such a role has a function of supporting or holding the cutting blade 34 that moves relative to the workpiece 31 in the direction indicated by the white arrow in the figure. It is important that it is done.

  Therefore, the holding means 32 plays a role of sharing and handling the force acting on the workpiece 31 at a position close to the cutting blade 4 at the time of cutting. Therefore, the holding means 32 does not hold the workpiece 31 completely, but supports the workpiece 31 from the direction opposite to the direction in which the cutting force acts on the workpiece 31. It can also be configured by a jig such as a guide plate that contacts the cutting material 31. As a member that holds and fixes the workpiece 31, a known chuck can be used as long as the workpiece 31 is gripped and fixed satisfactorily. However, when the workpiece 31 is to be gripped and fixed more strongly, the lower part of the fiber bundle 31a constituting a part of the workpiece 31 is solidified with a resin such as an adhesive, and this resin is used. The part may be held and fixed.

  Next, in the method of the present invention, an ultrashort fiber is manufactured by cutting the end face F of the material to be cut 31 made of the embedded fiber bundle. As a specific apparatus, an apparatus having a cutting mechanism used in a machine tool such as a well-known planer, sharpener, planer, or milling machine can be exemplified. However, in the present invention, such a well-known apparatus configuration can be used as it is, but a part of the mechanism and configuration of these known machine tools may be modified.

  In particular, regarding a workpiece to be attached to a work table (in the present invention, “a material to be cut 31 including a fiber bundle 31a embedded in an embedding material 31b”), in a planing machine, for example, a rail In the case of the present invention, it is necessary to arrange a large number of individual workpieces 31 arranged in parallel in the planing direction. It differs in point. However, also in the present invention, in a state where a large number of workpieces 31 are erected in parallel in a dense state, these are embedded again in the embedding material to form an integral block, It can also be supplied to the machine table.

  Therefore, an embodiment example in which an extremely short fiber is manufactured by incorporating substantially the same mechanism as that of a well-known planer into a part of the configuration of an extremely short fiber manufacturing apparatus will be described below.

  FIG. 19 shows a fiber bundle 31a in which a large number of workpieces 31 are arranged in parallel on a work table, and by cutting these workpieces 31, an embedding process is performed in an embedding material 31b. The embodiment which cuts the end surface F of this to short and obtains a very short fiber is illustrated. In FIG. 19, the first row (L1) to the eighth row (L8) in the vertical direction are parallel to each other from the first column (R1) to the sixteenth column (R16) in the horizontal direction. Although an example in which the workpieces 31 (8 rows × 16 columns) are erected on the work table is shown, the present invention has such a number and arrangement as long as the gist of the invention is satisfied. Needless to say, it is not limited.

  At this time, it is important that the group of workpieces 31 in which the cutting end surfaces F perpendicular to the length direction of the fibers are formed are aligned and fixed so that the cutting end surfaces F are all horizontal. This is because when at least one cutting blade 34 cuts the group of workpieces 31, the reference cutting end face F is aligned horizontally. However, it is not always necessary to level the cutting end face F before starting the planing of the workpiece 31. This is because, even if irregular cutting end faces F are formed before the planing, by rough cutting these cutting end faces F, the water level of the cutting end face F of the workpiece 31 can be obtained. is there. However, the rough cutting portion performed at this time has irregular cutting fiber lengths, and therefore needs to be removed before full-scale flat cutting is performed so as not to mix the extremely short fibers to be manufactured.

  Thus, when a large number of workpieces 31 are erected and prepared on a work table (not shown) as in the arrangement example shown in FIG. 19, the end surfaces F of these workpieces 31 are prepared. It goes without saying that the production of ultrashort fibers is markedly improved by simultaneously cutting a single material to be cut as compared with the case of individually cutting one workpiece. As already described, a large number of workpieces 31 are erected and arranged without gaps as described above, and a large number of workpiece groups 31 in such a dense arrangement state are arranged. Then, in order to fill up the standing spaces of the individual workpieces 31, these spaces are further filled with an embedding material, embedding treatment is performed, and these are integrated into a new “new covering”. A cutting material "may be used. And if the "new material to be cut" formed in this way is planed using a well-known planer or the like, a large amount of ultrashort fibers having an ultrashort fiber length of 0.005 to 1.0 mm. Can be manufactured.

  By the way, FIG. 19 shows an example of mass production of ultrashort fibers by arranging a large number of workpieces 31, but not only the workpiece 31 but cutting blades 34 as in the embodiment of FIG. 20. A large number of them may be installed in parallel, which can improve the production efficiency of ultrashort fibers. In FIG. 20, FIG. 20A shows a schematic front view, and FIG. 20B shows a schematic side view. In this embodiment, a large number of workpieces 31 are cut at a time by cutting blades 34 placed on 16 (4 × 4) tool posts 33 in the vertical and horizontal directions. Therefore, it is intended to mass-produce very short fibers.

  However, when the cutting blade 34 is cut and moved in the lateral direction as shown in FIG. 20B in the direction indicated by the white arrow in the figure, the protruding amount of the cutting blade 34 with respect to the workpiece 31 is shown. It goes without saying that each has been adjusted. For example, in FIG. 20B, the cutting blade 34 that cuts the workpiece 31 located at R7 is made of an extremely short fiber to be manufactured rather than the cutting blade 34 that cuts the workpiece 31 located at R8. The portion corresponding to the fiber length is provided so as to protrude toward the workpiece 31 side. Needless to say, these relationships are the same for the cutting blade 34 that cuts the workpiece 31 positioned at R9 and R10 in FIG. 20B.

Hereinafter, the manufacturing method of the very short fiber of this invention is demonstrated by an Example.
First, a single fiber group made of polyester is bundled to form a fiber bundle of 2 million dtex, and in a state of being made into a fiber bundle, this is frozen in a state immersed in water filled in a pot, and ice is used as an embedding material. A workpiece was obtained. And the cutting end surface of the obtained to-be-cut material 31 was cut | disconnected with the rotary cutter which has a circular cutting blade, the beautiful cutting surface was formed, and it was set as the cylindrical to-be-cut material 31 of (phi) 75 mm x 40 mm length. Using a device similar to that illustrated in FIG. 14, the workpiece 31 was sandwiched between gripping members made of a pair of half-split cylinders. Note that a jacket in which a refrigerant (brine) circulates was provided on the outer peripheral portion of the gripping member constituting a part of the holding means 32, and the holding means 32 was cooled to -4 ° C.

  Next, an air cylinder having a cylinder diameter of φ50 mm and a stroke length of 100 mm is adopted as the contact pressure applying means 35, and compressed air of 0.11 Mpa is supplied to the air cylinder, so that the workpiece 31 is cut into a blade. It pressed against the contact plane A of the table 33. Then, the rotary drive shaft (the tool post 33) was rotated at 30 revolutions per minute through the timing belt by the tool post 33 using an inverter motor with a reduction gear. At that time, the cutting blade 34 used was a high-speed steel having a thickness of 0.25 mm, a blade attachment angle of 25 °, and a blade retraction angle of 30 °. At this time, when the protrusion length of the cutting blade 34 was adjusted to 0.02 mm and cutting was performed, ultrashort fibers having a fiber length of 0.025 mm were obtained. After draining water from the obtained ultrashort fiber, it was dried with a hot air at 120 ° C. in a known hot air dryer. The cut surface of the ultrashort fiber after drying was in a clean state, and almost no miscut short fiber was seen.

  The ultrashort fiber obtained by the production method of the present invention is cut to have a fiber length of 0.005 mm or more and 1 mm or less, particularly 0.005 mm or more and 0.1 mm or less. For example, JP-A-11-241223 A very short optical interference fiber as described in the official gazette is mixed in an adhesive and used as a paint, mixed in cosmetics, or used as a flocking toner material for a printing press. A wide range of applications can be expected such as being able to be used.

  In addition, according to the production apparatus of the present invention, ultrashort fibers of 0.005 mm or more and 0.1 mm or less can be produced stably and easily, and further, the number of miscut products is greatly reduced, and the production yield thereof is thus reduced. Therefore, ultrashort fibers can be produced on an industrial scale.

FIG. 1 is a schematic explanatory view schematically illustrating a first embodiment for obtaining a fiber bundle for producing ultrashort fibers according to the present invention. FIG. 2 is a schematic explanatory view schematically illustrating each of the second embodiments for obtaining a fiber bundle for producing the ultrashort fiber according to the present invention. FIG. 3 is an embodiment in which the method of embedding the fiber bundle F wound up using the hexagonal winding frame illustrated in FIG. 1 is used as a specific example, and FIG. A plan view and FIG. 3B show a schematic side view, respectively. FIG. 4 is an explanatory view (plan view) schematically illustrating a treatment tank for embedding a fiber bundle with an embedding material. FIG. 5 is a schematic explanatory diagram for explaining a state in which the embedding treatment is performed by immersing the winding frame in which the fiber bundle is wound in the treatment tank filled with the embedding agent in a liquid state, FIG. 5A is a schematic plan view, and FIG. 5B is a schematic side view. FIG. 6 is a schematic side view schematically illustrating a state where the liquid embedding agent is cooled and solidified and then taken out from the treatment tank. FIG. 7 is a schematic explanatory view (plan view) schematically illustrated for explaining an embodiment of embedding processing performed in a state where the fiber bundle is separated from the winding frame. FIG. 8 is a schematic side view schematically illustrating a jig for applying a predetermined tension so that the fiber bundle is not greatly deformed when the fiber bundle is removed from the winding frame. FIG. 9 is an explanatory view schematically illustrating the fiber bundle embedding process. FIG. 10 is a cross-sectional view in the direction of arrows AA in FIG. 9, where FIG. 10A is an embodiment of a group of small fiber bundles having a rectangular cross section, and FIG. Each of the circular embodiment examples is shown. FIG. 11 is a schematic explanatory diagram for explaining the maximum required entry distance, which is a limit distance that allows the embedding agent to enter the inside of the small fiber bundle satisfactorily. FIG. 12 is an explanatory view schematically illustrating a method for removing bubbles contained in a small fiber bundle group. FIG. 13 is a schematic apparatus configuration diagram schematically showing an embodiment of a fiber bundle icing treatment apparatus. FIG. 14 is a schematic apparatus configuration diagram schematically illustrating the ultrashort fiber manufacturing apparatus of the present invention. FIG. 15 is an enlarged front sectional view of an essential part illustrating the cutting mechanism portion of FIG. 14 in an enlarged manner. FIG. 16 is a front sectional view schematically showing the adjustment of the protrusion length of the cutting blade. FIG. 17 is a schematic device configuration diagram schematically illustrating an embodiment of a cooling means for cooling a cutting blade and a workpiece. FIG. 18 is a schematic device configuration diagram schematically illustrating a cooling method in which a cutting blade is cooled using a Peltier element. FIG. 19 is a plan view schematically illustrating an arrangement in which a large number of workpieces are arranged in parallel on a work table. FIGS. 20A and 20B are explanatory views schematically illustrating a state in which a large number of cutting blades are installed in parallel and cut. FIG. 20A is a schematic front view, and FIG. 20B is a schematic side view. Show.

Claims (17)

A single fiber group having a single fiber fineness of 0.001 to 10 dtex is aligned so as to be parallel to each other in the fiber longitudinal direction to form a fiber bundle that is bundled so that the total fineness is 10,000 to 10 million dtex , embedding the fiber bundle by selecting water as a packing agent to embedding, to solidify the water to produce the cutting material obtained by embedding processing the fiber bundle in ice a Umatsutsumizai, the ice liquefied A method for producing an ultrashort fiber, characterized in that an ultrashort fiber having a cut fiber length of 0.005 to 0.1 mm is obtained by cutting a cut end face of a fiber bundle embedded at a temperature not to be cut into a thin piece.   The method for producing ultrashort fibers according to claim 1, wherein the ultrashort fibers to be produced are composite fibers made of at least two kinds of thermoplastic resins. When unwinding a yarn from at least one spool wound with a multifilament yarn composed of a large number of single fiber groups for winding, the yarns unwound from a plurality of spools are wound. In the case of taking, these yarns are combined and used for winding, and the single yarns constituting the fiber bundle having a predetermined total fineness are piled up by winding the yarns used for winding in parallel with each other. Winding while applying a predetermined winding tension to the winding frame in which the linear alignment portion is formed, the single fiber group constituting the fiber bundle is at least in a state where the single fiber group is linearly aligned On the other hand, an embedding process in which the water is allowed to enter between the single fiber groups forming the fiber bundle while solidifying the periphery of the fiber bundle to solidify, and the fiber bundle part that is arranged in a straight line after the embedding process is performed. The ultrashort fiber according to claim 1, which is cut to produce a workpiece. Production method. The winding frame is formed into a polygonal shape or a rod shape, and a bent portion of a fiber bundle is formed at each apex portion of the polygonal winding frame or both end portions of the rod-shaped winding frame. The method for producing ultrashort fibers according to claim 3 , wherein “linear alignment portions parallel to each other” are formed between the bent portions. The single fiber groups constituting the fiber bundle by fixing both ends to the outer ends of the fiber bundle portion used for the embedding process in the linear alignment portion formed on the winding frame are positioned at each other. After fixing the jig so as not to change the position, or impregnating the both ends with an adhesive, take out the fiber bundle from the take-up frame without taking out large deformation of the fiber bundle on the take-up frame and take it out. The method for producing ultrashort fibers according to claim 4 , wherein the embedding process is performed in a state in which a predetermined tension is applied to the fiber bundle. A plurality of small fiber bundles in which single fiber groups are aligned and bundled in parallel with each other are formed into a fiber bundle that is divided and arranged so as not to contact each other, and the water is introduced between the single fiber groups while surrounding the periphery of the fiber bundle. 2. The method for producing ultrashort fibers according to claim 1, wherein the material to be cut is produced by causing the water to undergo a phase change from a liquid state to a solid state and solidifying after the water enters. The method for producing ultrashort fibers according to claim 6 , wherein the small fiber bundle is formed so that a maximum required distance of entry into the center of the small fiber bundle by water does not exceed 5 mm. The method for producing ultrashort fibers according to claim 6 , wherein the small fiber bundle is flat. The method for producing ultrashort fibers according to claim 6 , wherein the water embedding agent phase-changed into a liquid state is degassed in advance. Before SL and was immersed standing in water filled in the freezing container fiber bundle, when fabricating the cutting material was frozen the fiber bundle in a state of being immersed in water, the air above the water from above the freezing container The method for producing ultrashort fibers according to claim 1, wherein the water surface portion is heated and the water surface portion is heated to prevent freezing of the water surface portion, and the water filled in the freezing container is subjected to freezing treatment. The method for producing ultrashort fibers according to claim 10 , wherein the air exhaust on the water surface is performed under a weak negative pressure of 30 Torr to 650 Torr. The method for producing ultrashort fibers according to claim 10 , wherein a surfactant is mixed in the water. The method for producing ultrashort fibers according to claim 10 , wherein the freezing treatment is performed while applying a slight vibration to the freezing container. The manufacturing method of the ultra-short fiber of Claim 10 which freeze-drys in the state which maintained the freezing of the said ultra-short fiber cut in the icing state. When manufacturing the ultrashort fiber by cutting the end face of the embedded fiber bundle into a thin piece, air is collected between the ultrashort fibers cut out in a frozen state, and the accumulated ultrashort fibers are collected. The ultrashort according to claim 14 , wherein the aggregate is made porous, the porous aggregate is kept at a temperature lower than the melting point of ice, and the cooled aggregate is subjected to freeze-drying. A method for producing fibers. A plurality of the workpieces are prepared, and the group of workpieces on which cutting end surfaces perpendicular to the length direction of the fibers are formed are fixed so that the cutting surfaces are horizontal, and the cutting surfaces are fixed by at least one cutting blade. The method for producing ultrashort fibers according to claim 1, wherein the cutting end face is flattened, and the ice is removed from the planed material to obtain ultrashort fibers having a fiber length of 0.005 to 0.1 mm. . The method for producing ultrashort fibers according to claim 16 , wherein the cutting agent is embedded in the ice integrally in a state where a large number of the fiber bundles are juxtaposed in a dense state.

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