US20060225252A1 - Method and device for manufacturing extremely short fiber - Google Patents

Method and device for manufacturing extremely short fiber Download PDF

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Publication number
US20060225252A1
US20060225252A1 US10/566,177 US56617704A US2006225252A1 US 20060225252 A1 US20060225252 A1 US 20060225252A1 US 56617704 A US56617704 A US 56617704A US 2006225252 A1 US2006225252 A1 US 2006225252A1
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Prior art keywords
shaving
ultrashort
fiber bundle
cut fibers
production
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US10/566,177
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English (en)
Inventor
Naohiko Shindo
Hajime Shibaike
Takuro Yoneda
Yasushi Kitagishi
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Teijin Frontier Co Ltd
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Individual
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Assigned to TEIJIN FIBERS LIMITED reassignment TEIJIN FIBERS LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KITAGISHI, YASUSHI, SHIBAIKE, HAJIME, SHINDO, NAOHIKO, YONEDA, TAKURO
Publication of US20060225252A1 publication Critical patent/US20060225252A1/en
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    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01G—PRELIMINARY TREATMENT OF FIBRES, e.g. FOR SPINNING
    • D01G1/00—Severing continuous filaments or long fibres, e.g. stapling
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01G—PRELIMINARY TREATMENT OF FIBRES, e.g. FOR SPINNING
    • D01G1/00—Severing continuous filaments or long fibres, e.g. stapling
    • D01G1/02—Severing continuous filaments or long fibres, e.g. stapling to form staple fibres not delivered in strand form
    • D01G1/025—Severing continuous filaments or long fibres, e.g. stapling to form staple fibres not delivered in strand form by thermic means, e.g. laser
    • D01G1/027—Severing continuous filaments or long fibres, e.g. stapling to form staple fibres not delivered in strand form by thermic means, e.g. laser by freezing

Definitions

  • the present invention relates to a process for production of ultrashort-cut fibers whereby numerous yarns composed of long individual filament groups are bundled to make a paralleled fiber bundle, and the fiber bundle is cut to produce ultrashort-cut fibers having a fiber length of no greater than 1 mm, as well as to an apparatus therefor.
  • Staple fibers with lengths of from several millimeters to several tens of millimeters have conventionally been obtained by bundling filaments made of thermoplastic synthetic positive such as polyesters or polyamides into a fiber bundle, and cutting the fiber bundle.
  • the cutting apparatus used has been, for example, a roller cutter type fiber bundle cutting machine which winds the fiber bundle on a cutter roller provided with a plurality of cutting blades arranged in a radial fashion, and presses the fibers wound on the cutting blades against the cutting blades while continuously cutting them to the prescribed length.
  • guillotine cutter type fiber bundle cutting machines which are provided with a fixed blade and a moving blade as shear blades and accomplish cutting by pressing the fiber bundle against the shear blades at a prescribed cutting length.
  • a guillotine cutter type fiber bundle cutting machine can handle cut fiber lengths of about 0.5 mm. Still, when it is attempted to use conventional types of fiber bundle cutting machines to cut long, thin fibers with a small individual filament size, the elasticity of the filaments themselves results in bending of the filaments, causing them to buckle or contact with the fixed blade at right angles. In addition, it is extremely difficult to adjust the clearance between the fixed blade and moving blade, resulting in miscutting such as slanted cuts or uneven cutting lengths.
  • the properly cut fibers when it is attempted to obtain staple fibers with consistent fiber lengths, the properly cut fibers must be selected and removed from among the many miscut fibers.
  • the selection and removal operation is not only very complex, but the yield of properly cut fibers is also impaired if large numbers of miscut fibers outside of the permissible cutting length range are present.
  • a guide is mounted upstream from the cutting zone of the continuously supplied filament bundle, in order to wrap the supplied fiber bundle with a continuous sheet-like member. After being laid so that the filament bundle running with the continuous sheet-like member which travels with the fiber, bundle becomes wrapped via the guide roller, the fiber bundle wrapped with the sheet-like member is cut. That is, wrapping the fiber bundle, which by itself alone is originally flexible and difficult to cut, with the sheet-like member stiffens it, and the stiffened fiber bundle is then cut to achieve cutting into staple fibers of the prescribed length.
  • the sheet-like member used to cover the fiber bundle to obtain such staple fibers must be paper, an organic polymer film such as polyolefin, polyester or cellophane, a cloth, a nonwoven fabric or the like.
  • the cut fibers and the sheet-like member must be separated after cutting. Accomplishing complete separation is difficult, and trace amounts of cutting scrap can be included in the cut fibers.
  • the fiber bundle must be bound more into a more rigid form to accomplish cutting more reliably. This has required the sheet-like member to have even greater stiffness, which has naturally placed limits not only on the materials that can be used but also on their handling.
  • each individual filament when each individual filament is removed from the individual filament group composing the fiber bundle, since each individual filament is very thin at, for example, 0.001-10 dtex and highly elastic, it is therefore easily deformed in the direction of the force from the cutting blade during cutting and escapes from the cutting blade. As a result, it is very difficult to properly cut the fiber bundle to a very short length of no greater than 0.1 mm at a satisfactory yield without miscutting.
  • Japanese Unexamined Patent Publication SHO No. 63-35829 proposes cutting aramid fibers which are difficult to cut with conventional cutting machines.
  • This prior art is a technique whereby a molten thermoplastic resin is impregnated into aramid fibers and cured, and the cured resin is pelletized, together with the fibers, using a pelletizer.
  • this prior art was developed to obtain fiber-reinforced plastic having short cut fibers kneaded therein, without requiring removal of the impregnated thermoplastic resin from the cut fiber bundle.
  • the technique does not isolate the cut fibers alone for their removal from the thermoplastic resin, and removal is completely irrelevant.
  • this prior art accomplishes pelletizing after impregnation of the thermoplastic resin in the fibers as mentioned above, and it is very difficult to pelletize fiber-containing resin cut to lengths of no greater than 0.1 mm using known pelletizers.
  • thermoplastic resin in terms of productivity of the ultrashort-cut fibers, a very large number of long thin individual filaments are bound to form a fiber bundle with a overall size exceeding 10,000 dtex, and these must be bound with the thermoplastic resin.
  • the terms “embedding agent” and “embedding material” are used, with the term “embedding agent” referred to a liquid state or gaseous state, and the term “embedding material” referring to a solid state.
  • the present invention therefore provides a process and an apparatus which allow stable production of ultrashort-cut fibers having fiber lengths of no greater than 0.1 mm (especially 0.005-0.1 mm) while minimizing miscutting.
  • the invention provides a process and apparatus whereby a fiber bundle is formed by binding numerous individual filament groups, an embedding material which is solidified by cooling and gasified or liquefied by heating is gasified or liquefied, the fiber bundle is embedded with the gasified or liquefied embedding material to prepare a shaving material, and the edge of the shaving material is thinly shaved at a temperature at which the embedding material does not gasify or liquefy, to obtain ultrashort-cut fibers having cut fiber lengths of no greater than 1.0 mm.
  • both ends of each linearly paralleled wound area is set by an embedding agent such as an adhesive, and the set section is cut to create a shaving material.
  • both ends of the linearly paralleled wound area may be held by clamping with a pair of fasteners, adhesive tape or the like while the fiber bundle is cut at both outer ends from the pair of fasteners, to create a fiber bundle which is paralleled in a satisfactorily linear fashion.
  • the individual filament size is preferably 0.001-10 dtex, and the overall size of the fiber bundle composed of the individual filament groups is preferably 10,000-10 million dtex.
  • the fiber bundle paralleled in a satisfactorily linear fashion passes to the embedding step; however, residual air is present inside the fiber bundle.
  • the fiber bundle is therefore preferably allowed to stand in a satisfactorily paralleled state in the embedding container, and subjected to vacuum degassing.
  • the pre-degassed embedding agent in a liquid or gaseous state is then filled into the container and impregnated into the fiber bundle with the fiber bundle surrounded by the embedding agent.
  • the embedding step is preferably carried out while evacuating the container with an exhauster as a vacuum apparatus under slightly negative pressure with respect to atmospheric pressure, to avoid residual air bubbles in the interior.
  • the embedding agent used is preferably water which can be easily and inexpensively obtained in large quantities and is very easy to handle. If water is used, it will readily penetrate to the interior of the fiber bundle due to the low viscosity of water.
  • surfactants may be added including, for example, nonionic surfactants such as polyalkyleneglycol esters and ethers, anionic surfactants such as alkali metal salts of fatty acids, alkyl phosphates, sulfonates and sulfates, cationic surfactants such as quaternary ammonium salts and amphoteric surfactants such as alkali metal salts of aminocarboxylic acids, or alkylbetaines or the like, to allow the water to thoroughly penetrate the interior of the fiber bundle.
  • nonionic surfactants such as polyalkyleneglycol esters and ethers
  • anionic surfactants such as alkali metal salts of fatty acids, alkyl phosphates, sulfonates and
  • the invention produces ultrashort-cut fibers by shaving in the manner described above, and the shaving means used may be a well-known machine tool such as a planing machine, slotting tool, planing/molding machine or miller, or a modified type thereof.
  • the numerous prepared shaving materials are arranged in a densely parallel state by the process and apparatus described above. These may be again embedded in the embedding material in this aligned state to form an integrated block, which is used as the new shaving material and supplied to the machining bench. This will allow a large volume of ultrashort-cut fibers to be easily produced.
  • insulating means and/or cooling means are preferably provided to cool the holding means holding the shaving material, so that the embedding material forming part of the shaving material does not change from a solid state to a liquid or gaseous state. It will sometimes be preferable for the shaving blade to be cooled.
  • the embedding material used for the process and apparatus for production of ultrashort-cut fibers according to the invention as described above is most preferably dry ice or ice, because dry ice or ice has the advantage of allowing the ultrashort-cut fibers easily produced by natural drying, hot air drying or freeze drying to be separated from the thinly shaved shaving material.
  • dry ice or ice has the advantage of allowing the ultrashort-cut fibers easily produced by natural drying, hot air drying or freeze drying to be separated from the thinly shaved shaving material.
  • significant temperature changes can produce dimensional alterations and result in peeling between the combined polymers.
  • Particular care must be taken when drying optical interference fibers such as described in Japanese Unexamined Patent Publication HEI No. 11-241223.
  • FIGS. 1 and 2 are schematic drawings illustrating first and second embodiments for obtaining a fiber bundle prepared for production of ultrashort-cut fibers according to the invention.
  • FIG. 3 is a pair of drawings showing a concrete embodiment for a process of embedding a fiber bundle F wound using the hexagonal winding reel shown in FIG. 1 , wherein FIG. 3 ( a ) is a schematic plan view and FIG. 3 ( b ) is a schematic side view.
  • FIG. 4 is a schematic illustration (plan view) showing a treatment tank for embedding treatment of a fiber bundle with an embedding material.
  • FIG. 5 is a pair of schematic drawings illustrating the state of the embedding treatment in which the winding reel with the fiber bundle wound up thereon is immersed in a treatment tank filled with a liquefied embedding agent, wherein FIG. 5 ( a ) is a schematic plan view and FIG. 5 ( b ) is a schematic side view.
  • FIG. 6 is a schematic side view showing the state after the liquefied embedding agent has been cooled to solidity and then removed out of the treatment tank.
  • FIG. 7 is a schematic illustration (plan view) showing an embodiment of embedding treatment carried out with the fiber bundle cut out from the winding reel.
  • FIG. 8 is a schematic side view showing a jig for application of a prescribed tension without causing significant deformation of the fiber bundle when it is removed from the winding reel.
  • FIG. 9 is a schematic illustration showing embedding treatment of fiber bundles.
  • FIG. 10 is a pair of cross-sectional views along line A-A of FIG. 9 , wherein FIG. 10 ( a ) is an example of a group of small fiber bundles with rectangular cross-sections, and FIG. 10 ( b ) is an example of circular cross-sections.
  • FIG. 11 is a pair of schematic illustrations showing the maximum required infiltration distance as the critical distance to allow satisfactory infiltration of the embedding agent into the interior of small fiber bundles.
  • FIG. 12 is a schematic illustration showing a process for removal of air bubbles contained in small fiber bundle groups.
  • FIG. 13 is a simplified schematic configuration diagram showing an embodiment of a fiber bundle freezing treatment apparatus.
  • FIG. 14 is a simplified schematic configuration diagram showing an apparatus for production of ultrashort-cut fibers according to the invention.
  • FIG. 15 is a magnified front cross-sectional view of the essential part of the shaving mechanism section of FIG. 14 .
  • FIG. 16 is a schematic front cross-sectional view to illustrate adjustment of the protruding length of the shaving blade.
  • FIG. 17 is a simplified schematic configuration diagram showing an embodiment of cooling means for cooling of the shaving blade and the shaving material.
  • FIG. 18 is a simplified schematic configuration diagram showing a cooling system which effects cooling of the shaving blade utilizing a Peltier element.
  • FIG. 19 is a schematic plan view showing the layout of numerous shaving materials arranged in an array on a machining bench.
  • FIG. 20 is a pair of schematic illustrations showing the state of shaving with a plurality of shaving blades situated in parallel, wherein FIG. 20 ( a ) is a schematic front view and FIG. 20 ( b ) is a schematic side view.
  • the ultrashort-cut fibers to be produced according to the invention may be obtained from synthetic fibers composed of a polymer such as a polyester, polyamide or polyolefin, or conjugated synthetic fibers comprising a combination of two or more polymers, and are not particularly restricted. Specifically, they may be obtained from natural fibers such as silk, cotton or hemp, or semi-synthetic fibers such as cellulose fibers or acetate fibers.
  • Staple fibers cut to fiber lengths of between 1 mm and several tens of millimeters are generally produced by paralleling yarn composed of extremely small individual filament groups having individual filaments (also referred to simply as filaments) with sizes of 0.001-10 dtex, to arrange them parallel to each other in the direction of the filament lengths, and cutting the bound fiber bundle to short lengths.
  • the present invention requires a step of binding a plurality of yarns composed of numerous individual filament groups to prepare a fiber bundle in the process for production of staple fibers.
  • this preparation step it is essential to coil up the multifilament yarn in order to bind the fiber bundle in a parallel state in one direction. This is because if the individual filament groups composing the fiber bundle are oriented in a slanted direction and not parallel in one direction, the embedded individual filament groups become set in the slanted direction instead of being set orthogonally to the shaving direction.
  • shaving of the embedded fiber bundle in this state after embedding treatment of the fiber bundle with the embedding material as described hereunder, will cause the individual filament groups set in the slanted direction to be shaved in the slanted direction instead of in the orthogonal direction.
  • this problem is solved by, as a first embodiment, preparing one or more wound yarns which are formed by winding up the multifilament yarns composed of numerous individual filament groups.
  • the yarns are drawn out from the wound yarns and lap wound on a winding reel such as, for example, a known coiling reel while applying a prescribed tension, to obtain a paralleled fiber bundle.
  • a winding reel such as, for example, a known coiling reel while applying a prescribed tension
  • the fiber bundle obtained in this manner is embedded without being removed from the winding reel and while applying the same tension as during winding, so that the tension-applied fiber bundle is embedded and integrated in the embedding material.
  • both ends of the fiber bundle which was formed by lap winding the numerous yarns and was wound up in parallel, are completely bound with the same tension applied as during winding.
  • the binding of both ends of the fiber bundle may be accomplished by wrapping the periphery of the aforementioned ends with adhesive tape to prevent the individual filament groups of the fiber bundle from moving freely, or by holding them with the strong force of a clamp.
  • an adhesive may be impregnated into only the end sections to adhesively anchor together the individual filaments of the fiber bundle.
  • removal from the reel can be accomplished by cutting the tape section anchoring both ends of the fiber bundle, or the adhesively anchored sections.
  • removal if a fixture such as a stretcher is mounted in order to hold both ends of the fiber bundle and allow the tension-applied state to be obtained, removal of the fiber bundle cut from the reel can be carried out with the same degree of tightness without relieving the tension which holds the individual filament groups in parallel.
  • the prescribed tension is applied again to both ends of the cut fiber bundle before setting the fiber bundle in the embedding material.
  • the individual filament groups are bound in the same position by adhesive tape or the like as described above at both ends of the cut fiber bundle, they can be easily restored to the original satisfactory paralleled state by application of new tension.
  • FIGS. 1 and 2 are schematic drawings illustrating two different embodiments for production of ultrashort-cut fibers according to the invention. The embodiment shown in FIG. 1 will be explained first.
  • 1 is a winder, which may be a known hank winder for winding of hanks, and 2 is doubling means composed of a yarn guide or the like.
  • P represents a wound yarn group consisting of one or more wound yarns, and in the illustrated example consists of three wound yarns (P 1 , P 2 , P 3 ).
  • Multifilament yarns (y 1 , y 2 , y 3 ) composed of numerous filaments (individual filaments) are wound around each wound yarn (P 1 , P 2 , P 3 ).
  • Each of the yarns (y 1 , y 2 , y 3 ) is guided to the doubling means 2 , and after being doubled through the doubling means 2 , is wound up on the winder 1 .
  • the yarns (y 1 , y 2 , y 3 ) are reeled onto the winder 1 simultaneously as they are doubled after being unrolled and drawn out from the wound yarns (P 1 , P 2 , P 3 ), but the doubling step may also be detached. That is, the system may be designed to unroll and draw out each of the yarns (y 1 , y 2 , y 3 ) from the wound yarns (P 1 , P 2 , P 3 ) and double them, forming from the doubled yarn y alone a single wound yarn suitable for supply to the winder 1 , and supplying the doubled yarn y to the winder 1 .
  • the operation can be carried out more efficiently when preparing a plurality of fiber bundles F by a plurality of winders 1 , eliminating the need to prepare a plurality of wound yarns (P 1 , P 2 , P 3 ) for each winder.
  • the yarn group y obtained by doubling the yarns (y 1 , y 2 , y 3 ) composed of multifilaments (numerous individual filament groups) having individual filament sizes of, for example, 0.001-10 dtex is bound with the filaments arranged in parallel in the direction of the fiber lengths, to prepare a fiber bundle F with an overall size of 10,000 to 10 million dtex.
  • a reel 10 is provided which lap winds the yarn group y supplied from the wound yarn group P onto the winder 1 the necessary number of times, to obtain a fiber bundle F having the prescribed overall-size.
  • the reel is provided with winding width controlling members 11 which control the reeling width of the fiber bundle F to the prescribed size.
  • the reel 10 is constructed from a hexagonal frame, and twelve winding width controlling members 11 are provided as shown at the vertices on the hexagonal reel 10 .
  • the doubled yarn group y becomes lap wound as a fiber bundle F on the winding width controlling members 11 , without directly contacting the reel 10 .
  • the shape of the reel 10 is preferably a polygonal shape having a greater number of sides than the regular hexagon of this embodiment, although it may also be a regular triangle or square.
  • This hexagonal reel 10 will be referred to for convenience in the explanation of the examples of the invention provided below, but it is understood that the invention is not limited to these examples, as mentioned above.
  • the fiber bundle F formed on the reel 10 in this manner only the sections Fs which are paralleled in a linear fashion suitable for shaving are utilized as the shaving materials for production of ultrashort-cut fibers. Since the reel 10 is hexagonal in the example shown in FIG. 1 , six fiber bundle (Fs 1 , Fs 2 , . . . , fs 6 ) sections are provided as materials for production of shaving materials to be embedded in the embedding material.
  • 12 is a tension detector which is used for tension control during winding while the tension of the supplied yarn group y is controlled to within the prescribed, tension range.
  • the method of unrolling each yarn (y 1 , y 2 , y 3 ) from the wound yarns (P 4 , P 2 , P 3 ) is a “vertical drawing system”. In this type of system, unrolling of the wound yarns (y 1 , y 2 , y 3 ) introduces an unrolling twist for each unrolling.
  • a “horizontal drawing system” may be employed wherein the wound yarns (P 1 , P 2 , P 3 ) are rotated for unrolling of the yarns (y 1 , y 2 , y 3 ).
  • tension compensators 3 ( 31 , 32 , 33 ) commonly employed in preparatory steps such as warping machines for warping of warp to be supplied for weaving, are preferably provided for each yarn (y 1 , y 2 , y 3 ) when unrolling and drawing out each yarn (y 1 , y 2 , y 3 ) from each wound yarn (P 1 , P 2 , P 3 ).
  • these tension compensators 3 are provided for each wound yarn (P 1 , P 2 , P 3 ), and are generally used to stabilize the unrolling tension in order to avoid significant variation in the unrolling tension during unrolling of the yarns (y 1 , y 2 , y 3 ) from each wound yarn (P 1 , P 2 , P 3 ).
  • the tension compensators 3 used may be commercially available ceramic products which have low friction coefficients and abrasion resistance, and will not be explained further here.
  • each of the yarns (y 1 , y 2 , y 3 ) is unrolled from each wound yarn (P 1 , P 2 , P 3 ) via a tension compensator 3 to avoid extreme variation in the unrolling tension.
  • the winding is carried out at a predetermined constant tension to improve paralleling of the fiber bundle F wound up on the reel 10 .
  • the following explanation however, relates to a system wherein the doubling step is linked to the step of winding onto the reel 10 by the winder 1 .
  • the winder 1 of the invention is provided with a tension detector 12 which detects the tension of the supplied yarn group y in order to control the winding tension. Winding is performed while controlling the winding speed of the winder 1 so as to maintain a constant tension as detected by the tension detector 12 .
  • a torque motor is used as the driving motor (not shown) for rotation of the reel 10 , and may be adjusted for winding at a constant torque.
  • the yarn group y it is essential according to the invention for the yarn group y to be lap wound onto the reel 10 at a predetermined constant tension, regardless of the winding system or winding mechanism used.
  • a preferred embodiment of the winder 1 of the invention is a winder having a traverse mechanism 13 , wherein during winding of the fiber bundle F on the winding width controlling members 11 , the yarn group y supplied to the reel 10 is wound up with traverse movement by a traverse guide (not shown) matching the winding width of the controlling members 11 . This is because winding up the yarn group y on the winding width controlling members 11 with proper alignment in the widthwise direction will result in improved paralleling of the fiber bundle F.
  • each fiber bundle (Fs 1 , Fs 2 , . . . , Fs 6 ) in the fiber bundle F wound on the reel 10 , wound up at the six locations corresponding each side of the hexagonal reel, can be maintained in a tightened state by the tension applied during winding, and can thus be wound up in a linear fashion. Since the fiber bundles (Fs 1 , Fs 2 , . . . , Fs 6 ) at the straight sections are in a very satisfactory paralleled state, those sections, when directly embedded into the embedding material described above, form a suitable shaving material material for obtaining ultrashort-cut fibers.
  • a quick-drying adhesive which satisfactorily infiltrates into the individual filament groups is impregnated into the fiber bundles (Fe 1 , Fe 2 , . . . , Fe 6 ) wound at the vertices of the hexagonal frame together with the fiber bundles (Fs 1 , Fs 2 , . . . , Fs 6 ) which are wound at the straight sections on the reel 10 .
  • the adhesive is then hardened to anchor the fiber bundles (Fe 1 , Fe 2 , . . . , Fe 6 ), as a preferred embodiment of the invention.
  • the anchored sections of the fiber bundle (Fe 1 , Fe 2 , . . . , Fe 6 ) are not linearly paralleled, they are unsuitable as shaving materials for shaving to obtain ultrashort-cut fibers. According to the invention, therefore, it is preferred to adhesively anchor these sections (Fe 1 , Fe 2 , . . . , Fe 6 ) which cannot be used as shaving materials.
  • the fiber bundles (Fe 1 , Fe 2 , . . . , Fe 6 ) to be anchored with an adhesive, this is not essential.
  • the reel 10 of the invention described above was a regular polygonal frame such, as the hexagonal frame shown in FIG. 1 .
  • the reel of the invention is not limited to this example, and may be instead a reel 10 ′ having a frame which is not regular polygonal, as illustrated in FIG. 2 .
  • the reel shown in FIG. 2 is provided with winding width controlling members 11 ′ at both ends of a rod-shaped reel 10 ′, and the two winding width controlling members 11 ′ act as loop back members to lap wind the yarn group y′ on the winding width controlling members 11 ′, in order to obtain a fiber bundle F′ having a prescribed overall size.
  • the doubled yarn group y is looped back, and wound at the winding width controlling members 11 ′.
  • the tension variation is greater than with a polygonal reel such as the hexagonal reel 10 of FIG. 1 . Therefore, in the winder 1 ′ used in this example, it is necessary to reduce the effect of the large variation in unrolling tension when each yarn of the yarn group y′ is unrolled from the wound yarn group P′. It is preferred, therefore, to provide a tension compensator 3 ′ for each wound yarn P′ to prevent increase in the range of variation in the unrolling tension.
  • the rotation of a servomotor 14 ′ is controlled while detecting the winding tension with a tension detector 12 ′.
  • the yarn group y′ doubled with the doubling means 2 ′ is wound above it at the prescribed winding tension by a traverse apparatus 13 ′ on the rod-shaped reel 10 ′.
  • the fiber bundle production process and apparatus of the invention as described above can yield a fiber bundle prepared for a prescribed overall size of 10,000 to 10 million dtex, and in a satisfactorily paralleled state.
  • a step of embedding treatment of such a satisfactorily paralleled fiber bundle with an embedding material in order to obtain ultrashort-cut fibers by shaving will now be explained in detail with reference to FIGS. 3 to 6 .
  • the embedding treatment with the embedding material may be carried out with the fiber bundle wound on the polygonal reel 10 illustrated in FIG. 1 or the rod-shaped reel 10 ′ illustrated in FIG. 2 .
  • FIG. 3 shows a concrete embodiment for a process of embedding a fiber bundle F wound up using the hexagonal winding reel 10 shown in FIG. 1 , wherein FIG. 3 ( a ) is a schematic plan view and FIG. 3 ( b ) is a schematic side view.
  • FIG. 4 is a schematic illustration (plan view) showing a treatment tank 4 for embedding treatment of a fiber bundle F with an embedding material 5 .
  • FIG. 5 is a pair of schematic drawings illustrating a step of embedding treatment in which the winding reel 10 with the fiber bundle F wound thereon is immersed in a treatment tank 4 filled with a liquefied embedding agent 5 , wherein FIG. 5 ( a ) is a schematic plan view and FIG. 5 ( b ) is a schematic side view.
  • FIG. 6 is a schematic side view showing the state after the liquefied embedding agent 5 has been cooled to solidity and then removed out of the treatment tank 4 .
  • the terms “embedding agent” and “embedding material” are both used, with the term “embedding agent” referred to the liquid state or gaseous state, and the term “embedding material” referring to the solid state.
  • the reel illustrated is a hexagonal one as in FIG. 1 , but there is no limitation whatsoever to this type so long as it satisfies the gist of the invention.
  • the embedding treatment can be carried out directly using the reel 10 with the fiber bundle F wound thereon.
  • the reel 10 is demounted from the winder 1 as the first step, it is essential to keep the fiber bundle in a tightened state without deformation, in order to satisfactorily maintain the paralleled state of the fiber bundle F wound on the winding width controlling members 11 as explained above.
  • the mechanism is preferably such that when the lock is released, the reel 10 is freely attachable/detachable from the rotation driving axis. This will allow the reel 10 to be demounted from the winder 1 without directly contacting with the wound fiber bundle F.
  • the next step employs a treatment tank 4 prepared having a hexagonal shape as shown in FIG. 4 , corresponding to the hexagonal reel 10 of this embodiment.
  • the treatment tank 4 is filled with the liquid embedding agent 5 (for example, water, molten paraffin or molten resin).
  • the treatment tank 4 is equipped with a heating apparatus for heating of the treatment tank 4 to allow melting.
  • the reel 10 with the fiber bundle F wound thereon is immersed in the treatment tank 4 filled with the liquid embedding agent 5 as explained above.
  • the reel 10 with the fiber bundle F wound thereon may be placed, together with the treatment tank 4 , in a vacuum container for vacuum degassing, to accomplish embedding treatment of the vacuum degassed fiber bundle F.
  • the straight sections necessary for shaving of the embedded fiber bundle F to obtain ultrashort-cut fibers are cut out with a cutter, to obtain shaving materials.
  • the cutter is used for cutting out of the sections indicated by dotted lines as shown in FIG. 6 , for example.
  • the straight fiber bundle (Fs 1 , Fs 2 , . . . , Fs 6 ) sections shown in FIG. 1 may be supplied as shaving materials for production of ultrashort-cut fibers.
  • the embodiment described above accomplishes embedding treatment by removal of the reel 10 or 10 ′ from the winder 1 or 1 ′, using the reel 10 or 10 ′ with the fiber bundle F or F′ wound around the winding width controlling members 11 or 11 ′, and this process is preferred according to the invention.
  • the invention is not limited to this example, and as mentioned above, the fiber bundle F or F′ treated with an adhesive, or clamped, may be cut out from the reel 10 or 10 ′ and subjected to embedding treatment after being cut out from the reel 10 or 10 ′. This type of embedding treatment will now be explained in detail with reference to FIGS. 7 and 8 .
  • FIG. 7 is a schematic illustration (plan view) showing an embodiment of embedding treatment carried out with the fiber bundle F cut out from the reel 10 .
  • split embedding agent-filled containers 6 are mounted at the straight fiber bundle (Fs 1 , Fs 2 , . . . , Fs 6 ) sections shown in FIG. 1 .
  • the embedding agent-filled containers 6 have split structures, and preferably when the split sections are joined, they are fitted on the straight fiber bundle (Fs 1 , Fs 2 , . . .
  • the seals may be enhanced by using a liquid or paste-like sealing agent as an auxiliary agent for the seal.
  • the liquid embedding agent 5 is circulated through the embedding agent-filled containers 6 through in ports 6 a and out ports 6 b . Air bubbles present in the fiber bundle F and the air present in the embedding agent-filled containers 6 are forced out when the embedding agent 5 is filled into the embedding agent-filled containers 6 .
  • the embedding agent-filled containers 6 may be cooled in this state to minus temperature for freezing of the internal water, to accomplish successful embedding of the fiber bundle F with an embedding material composed of ice.
  • the reel 10 may have a freely collapsible structure, whereby the reel 10 alone is shrunken and demounted without cutting the fiber bundle F, and the fiber bundle F alone may be subsequently removed out.
  • the six rod-shaped frames extending out in a radial fashion which support the winding width controlling members 11 shown in FIG. 1 may have a telescopic structure or a freely foldable structure employing hinges, for expansion and collapse.
  • the fiber bundle F can be easily removed from the reel 10 in this manner, it will be possible to restore the fiber bundle F to the original satisfactory paralleled state by holding both ends of the adhesive-treated sections and applying the prescribed tension. In this case, care must be taken to avoid major deformation of the removed fiber bundle F when the fiber bundle F is removed from the reel 10 . This is because major deformation of the removed fiber bundle F can cause deformation of the individual filament groups of the fiber bundle F at sections other than the sections anchored with the adhesive, causing them to shift their relative positions. With application of low tension, therefore, friction between the filaments can become significant, producing a condition in which it will be difficult to restore the individual filaments to the original positions.
  • a stretching jig 7 is built to apply the prescribed tension in the directions of the arrows in order to avoid major deformation of the fiber bundle F during demounting of the fiber bundle F, and the jig 7 is fitted at the straight fiber bundle (Fe 1 , Fe 2 , . . . , Fe 6 ) sections which are wound on the reel 10 .
  • a modification wherein the fiber bundle F is cut out from the outer ends of the jig 7 is preferred, taking care to avoid major deformation of the fiber bundles (Fe 1 , Fe 2 , . . . , Fe 6 ) at these sections.
  • This will allow each jig to be supplied for embedding treatment instead of the reel 10 shown in FIGS. 3 to 6 , and thereby further facilitate the embedding treatment shown in FIGS. 3 to 6 .
  • Each of the strands of the individual filament groups of the fiber bundle F are generally very thin and flexible. Consequently, since they readily undergo elastic deformation in the direction of the cutting force and slip away from the blade, as mentioned above, it is normally not easy to produce ultrashort-cut fibers with fiber lengths of 0.1 mm or smaller. According to the invention, however, the individual filament groups of the fiber bundle F are set with the embedding material and their freedom of movement is therefore restricted, to prevent them from easily moving. The fiber bundle F set by the embedding material is then cut into thin slices using a shaving blade.
  • the embedding agent must have a property allowing it to be converted to a low viscosity fluid state, whereby the fiber bundle can be easily surrounded to allow the agent to envelop and infiltrate into the interstice of the fiber bundle from the periphery.
  • FIG. 9 is a schematic partial front cross-sectional view of an embodiment of embedding treatment of fiber bundles by the process for production of ultrashort-cut fibers according to the invention.
  • FIG. 10 is a pair of cross-sectional plan views along line A-A of FIG. 9 .
  • FIG. 10 ( a ) shows an embodiment of small fiber bundles with flat rectangular cross-sections (cross-section in the direction orthogonal to the direction of fiber lengths), and
  • FIG. 10 ( b ) shows an embodiment of small fiber bundles with non-flat circular cross-sections.
  • F represents small fiber bundles
  • 12 is the embedding agent (embedding material)
  • 13 is the container
  • 13 a is an in port for liquid-phase converted embedding material
  • 14 is a clamping member.
  • the small fiber bundles F are prepared by aligning yarn groups y and bundling them in a straight paralleled state, and then cutting both ends to create equal lengths of the small fiber bundles F.
  • the group of small fiber bundles F are anchored by the clamping member 14 which clamps and anchors both ends of each of the small fiber bundles F prepared in the manner described above.
  • the group of small fiber bundles F anchored by being clamped by the clamping member 14 must be situated with an appropriate spacing W between adjacent small fiber bundles F so that the embedding agent 12 which has undergone phase conversion to liquid can surround the small fiber bundles F and penetrate to their interiors.
  • the optimum value for the spacing W may be determined by experimentation, since the ease of infiltration between the small fiber bundles F will differ depending on the nature of the embedding agent 13 used. For example, when water which has undergone phase conversion to a liquid state is used, the spacing is preferably 0.5 mm or greater, and more preferably 2 mm or greater.
  • the freedom of movement of the long individual filament groups of the small fiber bundles F is restricted by being anchored with the embedding material 12 . It is therefore essential for the embedding agent 12 which has undergone phase conversion to a liquid state to be able to easily reach the deepest center sections of the small fiber bundles F after the agent has been introduced between the small fiber bundles F so as to surround the periphery of the group of small fiber bundles F.
  • FIG. 11 shows an example of a small fiber bundle F having a flat rectangular lateral cross-section, and (b) shows an example of a small fiber-bundle F having a flat oblong lateral cross-section.
  • L represents the center line.
  • the embedding agent 12 which has undergone phase conversion to a liquid state can easily surround the periphery of the small fiber bundles F since the small fiber bundles F are aligned without mutual contact, at a prescribed spacing W.
  • the problem is how to allow the embedding agent 12 thus surrounding the periphery of the small fiber bundles F to easily reach the deepest interiors of the small fiber bundles F.
  • the “maximum required infiltration distance dmax” is always the same value along the lengthwise direction of the lateral cross-section as shown, while in the case of FIG. 11 ( b ), the maximum required infiltration distance dmax is at the position of maximum thickness of the small fiber bundle F at the lateral cross-section, as shown.
  • vertical/horizontal ratio is the “short side length/long side length” for the fiber bundle F having the rectangular cross-section in FIG. 11 ( a )
  • the “vertical/horizontal ratio” is the “short diameter length/long diameter length” for the fiber bundle having the oblong cross-section in FIG. 11 ( b ).
  • the maximum required infiltration distance dmax must, not exceed 5 mm. This is because when thin individual filament groups of 0.001-10 dtex are bundled, the interstices between the individual filament groups are extremely small. The embedding agent 12 is therefore unable to adequately infiltrate to the interior. As a result, since an increased small fiber bundle F thickness will not allow the embedding agent 12 to infiltrate to the deepest sections of the small fiber bundles F, the maximum required infiltration distance dmax must not exceed 5 mm.
  • the small fiber bundles F are in a densely arranged state, it becomes difficult for the embedding agent 12 to infiltrate to the deepest sections of each small fiber bundle F.
  • the arrangement so long as the small fiber bundles F are arranged at the prescribed spacing without contact.
  • the lattice arrangement shown in the drawing or any desired arrangement such as circular, zig-zag or the like, as appropriately selected within a, range which satisfies the gist of the invention.
  • embedding agents 12 which may be suitably used, there are preferred agents with excellent permeability and dispersability, to facilitate infiltration between the individual filament groups.
  • a surfactant in admixture with the embedding agent 12 which has undergone phase conversion to a liquid state can facilitate impregnation of the embedding agent to the interior of the small fiber bundles F.
  • Water in admixture with a surfactant may be mentioned as an example of such an embedding agent.
  • the small fiber bundles F to be embedded have minute spaces in their interiors as mentioned above, and naturally, the spaces contain air in their ordinary state. Consequently, if the air remains in that state in the groups of small fiber bundles F, the air between the individual filament groups will constitute a hindrance when the fiber bundle composed of the bundled groups of small fiber bundles F is immersed in the embedding agent 12 , thereby preventing thorough infiltration of the embedding agent 12 into the small fiber bundles F.
  • FIG. 12 As a schematic illustration of producing fiber bundles according to the invention.
  • 13 represents containers for embedding treatment similar to the one shown in FIG. 9, 15 represents a degassing tank, 16 represents a vacuum aspirator and 17 represents a vacuum tube.
  • the group of small fiber bundles F are placed in the container 13 , as shown in FIG. 9 and FIG. 10 . Also, after the group of containers 13 has been placed in the degassing tank 15 and the degassing tank 15 sealed for airtightness, the air in the degassing tank 15 is aspirated by the vacuum aspirator 16 through the vacuum tube 17 . Once a vacuum state has been produced, the embedding agent is injected into the container 13 through the in port 13 a of the container 13 using a volumetric pump, and the prescribed amount of embedding agent is filled into each container 13 for adequate infiltration of the embedding agent into the fiber bundle F.
  • the vacuum state may be a degree of vacuum which can be ordinarily achieved with the vacuum aspirator 16 , and there are no necessary restrictions on the degree of vacuum.
  • a preferred degree of vacuum is, for example, about 10-300 Torr.
  • a vacuum of below 10 Torr is not preferred as it will result in extreme vaporization if water is used as the embedding agent, thus requiring use of excess water in the amount of vaporization.
  • a vacuum of above 300 Torr is also not preferred because it will not allow adequate removal of the air bubbles in the fiber bundle interiors.
  • the embedding agent 12 is still in a liquid state after completion of degassing, and therefore the individual filament groups must be anchored with the embedding agent by its phase change to a solid state.
  • the completely degassed degassing tank 15 is opened to the atmosphere to allow cooling of the group of containers 13 in the degassing tank 15 , thereby solidifying the embedding agent 12 to obtain a solid embedding material 2 .
  • the group of containers 13 containing the fiber bundles F is placed in the degassing tank 15 and then the air in the degassing tank 15 is vacuum aspirated to force out the air inside the group of containers 13 , before injecting the embedding agent into the group of containers 13 .
  • the embedding agent 12 may be filled into the group of containers 13 first, and the group of containers 13 filled with the embedding agent 12 placed in the degassing tank 15 for vacuum aspiration.
  • the degassing tank 15 may be cooled with the degassing tank 15 in an evacuated state to solidify the embedding agent 12 .
  • the degassing tank 15 may be pressurized to a high pressure for pressurized degassing of the air bubbles in the embedding agent 12 .
  • the method described above may be used in combination with admixture of the embedding agent 12 with a surfactant having affinity with fibers and a defoaming property.
  • the common example of a surfactant used in clothing detergent may serve for explanation of the surfactant mixed with the embedding agent 12 .
  • a surfactant surrounds oil and dirt components adhering to clothing fibers, penetrating the gaps between the fibers and the oil and dirt components, and eventually eliminating the oil and dirt from the fibers. Therefore, using the embedding agent 12 in admixture with a surfactant can result in satisfactory penetration of the embedding agent 12 into the spaces between the individual filament groups.
  • the embedding agent 12 penetrates into the minute spaces between the individual filament groups and wets the individual filament groups, trace amounts of air may still reside between the individual filament groups, but the action of the surfactant will allow the embedding agent to surround the trace amounts of air and isolate the residual trace amounts of air for their removal.
  • the embedding agent will have greater affinity with the individual filament groups to allow more satisfactory embedding treatment.
  • Surfactants with such a function include nonionic surfactants such as polyalkyleneglycol esters and ethers, anionic surfactants such as alkali metal salts of fatty acids, alkyl phosphates, sulfonates and sulfates, cationic surfactants such as quaternary ammonium salts and amphoteric surfactants such as alkali metal salts of aminocarboxylic acids, or alkylbetaines or the like.
  • nonionic surfactants such as polyalkyleneglycol esters and ethers
  • anionic surfactants such as alkali metal salts of fatty acids, alkyl phosphates, sulfonates and sulfates
  • cationic surfactants such as quaternary ammonium salts and amphoteric surfactants such as alkali metal salts of aminocarboxylic acids, or alkylbetaines or the like.
  • the embedding agent 12 is preferably boiled to drive out the gas components dissolved in the embedding agent 12 . This will prevent bubbling of the air dissolved in the embedding agent 12 , for any of various reasons, during the embedding treatment. Generation of bubbles in the fiber bundles F can therefore be inhibited, to reinforce the binding force of the solidified embedding material on the individual filament groups.
  • the embedding agent 12 is preferably solidified by gradual phase conversion over a sufficient period of time, and for example, a long period of time from 8 to 48 hours, in order to inhibit generation of air bubbles in the fiber bundles F during the procedure.
  • a period of less than 8 hours is not preferred because the embedding agent 12 will solidify before the air bubbles in the fiber bundles F escape, and air bubbles will therefore be left in the fiber bundles F.
  • a period of greater than 48 hours is not preferred from the standpoint of production efficiency, since production of the fiber bundles F will be excessively lengthened.
  • the means for adjusting the time to solidification of the embedding agent 12 may involve appropriate selection of the method of adjusting the cooling temperature and the method of automatically reducing the cooling temperature in a stepwise manner.
  • FIG. 13 shows an embodiment of a freezing treatment apparatus for freezing treatment.
  • FIG. 13 is a simplified configuration diagram showing the construction of the apparatus for schematic illustration of the freezing treatment method and freezing treatment apparatus of the invention.
  • the freezing treatment apparatus of the invention comprises a refrigerating device 21 , a freezing vessel 22 , an fixture 23 , a vacuum chamber 24 , a gas-liquid separator 25 , an exhauster 26 , a heating device 27 , a microvibrator 28 and a control apparatus 29 .
  • the section enclosed by the two-dot chain line in FIG. 13 is the refrigerating device 21 composed of, for example, a freezer or the like, and it is provided to freeze the water (embedding agent) infiltrated in the fiber bundles F standing in the freezing vessel 22 , whereby the fiber bundles F are subjected to freezing treatment (embedding treatment) by the ice (embedding material).
  • the refrigerating device 21 is not limited to a freezer, and may be a system which immerses the freezing vessel 22 in a refrigerant bath.
  • the fiber bundles F in a parallel state have both ends anchored by the fixture 23 , and the ends are cut outside the fixture 23 .
  • the fiber bundles F are allowed to stand suspended in the freezing vessel 22 filled with the separately degassed water while anchored by the fixture 23 .
  • the vacuum chamber 24 also serving as the cover member of the freezing vessel 22 , is provided at the top of the freezing vessel 22 .
  • the heating device 27 is provided around the periphery of the vacuum chamber 24 to heat the vacuum chamber 24 during freezing treatment.
  • the heating device 27 is provided to delay freezing from the water surface formed by the water filling the freezing vessel 22 . Specifically, the density of the water supplied to the freezing treatment is greatest at 4° C., and therefore the heating device 27 is used to prevent the freezing from starting at the water surface formed at the cover member, with water at 0° C. pressing against the cover member of the freezing vessel 22 above it.
  • the reason for this is that if the water surface formed in the cover member of the freezing vessel 22 freezes, the air dissolved in the lower water will result in an increased concentration of dissolved air in the water as ice is produced on the water surface, eventually producing bubbles in the water. In addition, the bubbled air will be kept from escaping and will be enclosed in the interior by the ice already formed above. However, heating of the cover member of the freezing vessel 22 by the heating device 27 prevents freezing of the water surface formed at the cover member. This allows the bubbled air to easily escape from the unfrozen surface. Bubbling of the air dissolved in the water when the water in the freezing vessel 22 freezes occurs because water has an air solubility of 2.78 ⁇ 10 ⁇ 2 at 0° C. in air while the solubility of air in frozen ice is zero, such that the air dissolved in the water will reside in the ice as a gas as the water freezes.
  • the aforementioned cover member also serves as the vacuum chamber 24 , and the air bubbled from the vacuum chamber 24 is discharged by the exhauster 26 .
  • the heating device 27 it is preferably controlled so as to set the desired heating temperature and heating time.
  • a concrete means for achieving this is to provide a control apparatus 29 which controls the heating temperature.
  • the heating temperature and heating time for the heating device 27 is preferably set based on experimentation. For example, there is no reason to operate the heating device 27 after the total amount of water in the freezing vessel 22 has been completely frozen by the refrigerating device 21 . On the contrary, this would be disadvantageous from the standpoint of running cost since the refrigerating device 21 must then be used in a continuous manner. In the production process for ultrashort-cut fibers, both ends of the freeze treated fiber bundle are cut off by a cutter. Consequently, there is little point in continuously carrying out the refrigeration procedure until the total amount of water filling the freezing vessel 22 is completely frozen. Therefore, if the freezing treatment of the fiber bundles F is already completed up to the portion cut off by the cutter, there is no further need to continue freezing of the fiber bundles F.
  • the gas-liquid separator 25 used to separate the gas and liquid is mounted after the vacuum chamber 24 the air present in the vacuum chamber 24 above the water surface is preferably evacuated under slightly negative pressure of 30-650 Torr by the exhauster 26 comprising a vacuum pump and air exhaust ventilator, through the exhaust pipe.
  • the degree of vacuum in the vacuum chamber 24 is preferably slightly negative pressure because an excessively large degree of vacuum will accelerate vaporization of the water filling the freezing vessel 22 more than is necessary, while also running up equipment and operating costs due to the construction required to achieve such a vacuum, and it is therefore not advisable.
  • the degree of vacuum is preferably not too low, because this will reduce the effect of forcing out bubbled air in the water during the freezing treatment.
  • aspirated discharge can be efficiently carried out in a continuous manner during freezing treatment (embedding treatment), therefore allowing the bubbled air to also be satisfactorily discharged during the freezing treatment.
  • this procedure is preferably combined with microvibration of the freezing vessel 22 in order to actively bubble the air dissolved in the water in the freezing vessel 22 , leading to fusion and growth of the bubbles to increase their buoyancy, and aiding their escape from the water surface held in an unfrozen state by heating.
  • microvibration of the fiber bundles F and water can separate the air attached to the fiber bundles F from the fiber bundle surfaces, and is very effective for this purpose.
  • “Microvibration” according to the invention also includes “ultrasonic vibration” whereby vibration is produced by ultrasonic waves.
  • an easily attachable/detachable microvibrator 28 is attached to the freezing vessel 22 at any desired position either at the side or bottom of the freezing vessel 22 , whereby the microvibrator 28 supplies microvibration to the entire freezing vessel 22 .
  • the microvibrator 28 used may be a known microvibrator such as an electromechanical vibrator, acoustic vibrator or the like.
  • the vibration frequency or amplitude produced by the microvibrator must be varied depending on the conditions such as the dimensions and shape of the freezing vessel 22 or the overall size of the fiber bundles F, and therefore it is preferably designed to allow variation to the prescribed value to match the conditions.
  • the fiber bundles F are subjected to freezing treatment with the microvibrator 28 attached to the freezing vessel 22 in the manner explained above.
  • the density of water at 0° C. is 0.9988 g/cm 3 while the density of ice at 0° C. is 0.917 g/cm 3 .
  • freezing of water in a freezing vessel 22 having a fixed volume can result in defects such as cracks or fractures due to internal stress caused by the expanded volume of the ice. If defects such as cracks or fractures occur in the frozen ice, problems may result to hinder satisfactory production of ultrashort-cut fibers with fiber lengths of 0.1 mm or smaller by thin shaving of the edges of the frozen fiber bundles F.
  • the freezing vessel 22 since the freezing vessel 22 is situated inside the refrigerating device 21 , the internal water will begin to freeze from the walls of the freezing vessel 22 , but as mentioned above, heating of the cover member by the heating device 27 causes this portion of water to be frozen last. Consequently, the ice growth occurs gradually from the bottom wall of the freezing vessel. 22 while microvibration is being applied to the unfrozen water, and therefore freezing of the water in the freezing vessel 22 proceeds from the bottom and sides of the freezing vessel 22 toward the top where the cover member is situated.
  • freezing begins from the top including the water surface and from the walls of the freezing vessel 22 and surrounds the unfrozen water, with freezing gradually proceeding toward the interior.
  • the unfrozen water enclosed in the interior begins to freeze, defects such as cracks and fractures are generated due to the internal stress of volume expansion of the ice.
  • the unfrozen water can move freely upward during the freezing for the reason described above. This reduces the internal stress due to volume expansion as the water undergoes phase conversion to ice, thereby preventing generation of defects such as cracks and fractures.
  • this freezing treatment of water in the freezing vessel 22 is highly effective even from the viewpoint of eliminating air bubbles in the ice serving as the embedding material.
  • the air bubbles in the ice serving as the embedding material can be eliminated by final freezing of the water containing bubbled air, while the air dissolved in the water to be frozen is bubbled in the unfrozen water. Consequently, the dissolved gas around the fiber bundles F is not frozen in the form of bubbles, making it possible to shave the bundles with the shaving blade and thus mass produce ultrashort-cut fibers with fiber lengths of for example, 0.1 mm and smaller at a high yield without miscutting.
  • a preferred embodiment according to the invention is to apply microvibrations to the water in the freezing vessel 22 with a constant temperature gradient between the top and bottom of the freezing vessel 22 , or to carry out the freezing while stirring at 50 rpm.
  • the bottom and sides of the freezing vessel 22 are preferably cooled to a temperature of ⁇ 1° C. to ⁇ 20° C.
  • the top (cover member section) of the freezing vessel 22 is preferably heated to a temperature of 0-5° C. This will keep the bottom and sides of the freezing vessel 22 at the prescribed low temperature while maintaining the prescribed higher temperature at the top, thus causing freezing of the water from the bottom toward the top of the freezing vessel 22 , so that the bubbled air will not be trapped in the freezing vessel 22 .
  • the unfrozen water will constantly be in motion. Air bubbles which might be trapped in the initial frozen water are therefore repelled and return to the unfrozen water. Eventually, the fiber, bundles F become embedded by clear ice with no air bubbles.
  • the temperature for cooling of the bottom of the freezing vessel 22 is ⁇ 1° C. to ⁇ 20° C. (preferably ⁇ 2° C. to ⁇ 5° C.) because at a higher temperature the temperature gradient will be too gentle, preventing freezing from the bottom of the freezing vessel 22 .
  • the water temperature for heating of the vacuum chamber 24 also serving as the cover member is 0-5° C. (preferably 0-2° C.) because keeping it at a lower temperature will cause freezing to start from the top of the freezing vessel 22 , thereby trapping the air bubbles and preventing them from escaping to the top.
  • the embedding material (embedding agent) used for the invention may be, instead of ice (water) as explained above, a material which when heated undergoes a phase change from solid to gas (gasification), such as dry ice, or a material which upon heating undergoes a phase change from solid to liquid (liquefaction), as does ice.
  • gasification a material which when heated undergoes a phase change from solid to gas
  • liquefaction a material which upon heating undergoes a phase change from solid to liquid (liquefaction), as does ice.
  • the individual filament groups of the fiber bundles F will solidify in a state of integration with the embedding material. This will prevent the individual filaments from easily slipping from the shaving blade when the shaving blade acts on the individual filaments, thereby allowing a greater force to be applied.
  • the fiber bundles F are embedded with the embedding material first.
  • Paraffin may also be suitably used as the embedding material in addition to the dry ice or ice mentioned above, while a thermoplastic resin having a much lower molecular weight than the fibers to be embedded may also be used.
  • Such low molecular weight thermoplastic resins are not particularly restricted so long as they have low melting points and melt viscosities, and can be easily separated from the ultrashort-cut fibers which are produced; for example, there may be used commonly known low molecular weight thermoplastic resins such as low polymerized polyesters, low polymerized polystyrene, low polymerized polyethylene and the like, selected as appropriate for use depending on the conditions.
  • the ultrashort-cut fibers and embedding material are easily and thoroughly separated after shaving in the ultrashort-cut fiber production process.
  • it is preferred to use dry ice or ice as the embedding material and as mentioned above, ice is particularly preferred.
  • ice is particularly preferred because, as mentioned above, a simple apparatus can be used for easy freezing of the fiber bundles.
  • the embedding material When a material other than dry ice or ice, such as paraffin or a thermoplastic resin, is used as the embedding material, it is possible to employ a method wherein, for example, the embedding material is melted by heating and then the melted embedding agent is dissolved with an organic solvent or the like and removed, after which a drying step is performed to effect separation and removal of the organic solvent from the ultrashort-cut fibers.
  • the production process of the invention can very satisfactorily prevent contamination of other materials into produced ultrashort-cut fibers as occurs in the prior art.
  • the embedding material can be easily and conveniently separated from the ultrashort-cut fibers at ordinary operating temperature (for example, room temperature kept at 20° C.), in order to accomplish shaving under conditions which do not result in gasification of the dry ice to produce carbon dioxide gas.
  • ordinary operating temperature for example, room temperature kept at 20° C.
  • ice When ice is used as the embedding material, it may be heated at a temperature above 0° C. and then subjected to a drying step for easy and convenient separation of the embedding material from the ultrashort-cut fibers. According to the invention, therefore, either heat drying or room temperature drying may be employed when using ice as the embedding material.
  • freeze drying which allows drying to be accomplished at low temperature may be used for the invention.
  • Freeze-drying is a drying method whereby moisture is removed by sublimation as water vapor from a state of ice adhered to the surface of the ultrashort-cut fibers passing through a state of water, and hence there is absolutely no need to heat the ultrashort-cut fibers and a low temperature can be maintained during the freeze drying. This will allow drying to be performed without the problems described above, and therefore when water (ice) is used as the embedding agent (embedding material), freeze drying is very convenient for drying of the water.
  • the ultrashort-cut fiber production process of the invention thinly shaves the edges of the frozen fiber bundles with a shaving blade and fresh shaving surfaces therefore appear one after another, the surface area is very large during production of the ultrashort-cut fibers.
  • the freshly produced shaving surfaces will overlap each other, thereby reducing the surface area despite the originally produced large surface areas.
  • the large surface area newly produced by shaving may therefore be used to maximal advantage.
  • the frozen ultrashort-cut fibers are preferably not aggregated under conditions in which the ice adhering to the obtained ultrashort-cut fibers will melt. If they are kept at a temperature at which ice melts to water, it will be necessary to refreeze the melted water because of the need for drying by a freeze drying method, thus resulting in a waste of energy. In addition, the freezing will occur with the peripheries of the ultrashort-cut fibers embedded in the water. As a result, it will not be possible to create the aforementioned porous state, thus rendering it difficult to increase the drying speed and consequently requiring a greater length of time to remove the moisture by freeze drying.
  • the housing means of the frozen ultrashort-cut fibers is traversely moved to produce a roughly consistent aggregating thickness of the shaved frozen ultrashort-cut fibers.
  • the frozen ultrashort-cut fibers for freeze drying while they are still housed in the housing means.
  • a minute opening is preferably formed on the contact surface where the housing means contacts with the shaved frozen ultrashort-cut fibers to allow sublimation of the ice as water vapor.
  • the present invention is characterized by producing ultrashort-cut fibers, not by cutting the fiber bundles F, but by thinly shaving a shaving material composed of the embedded fiber bundles.
  • FIG. 14 is a simplified schematic configuration diagram showing an apparatus for production of ultrashort-cut fibers according to the invention, wherein 31 is a shaving material (embedded fiber bundles to be shaved), 32 is holding means, 33 is a blade stand, 34 is a shaving blade, 35 is contact pressure applying means, 36 is driving means, 37 is protrusion length adjusting means (not shown in FIG. 14 ), 38 is ultrashort-cut fiber collecting means and 39 is a mounting frame.
  • the reference letter A represents the contact plane of the blade stand 33 which presses against the shaving edge of the shaving material 31 with a prescribed contact pressure, and since the contact plane A is the shaving base, it must be formed to have sufficient smoothness and flatness.
  • the insulating means and/or cooling means of the holding means 32 are not shown in FIG. 13 , but these will explained below.
  • the ultrashort-cut fiber collecting means collects the shaved ultrashort-cut fibers, and for example, it may be a collecting bag or cylindrical container, which is provided surrounding the perimeter of the rotating blade stand 33 .
  • the contact pressure applying means 35 performs the role of pressing the shaving material against the contact plane A of the blade stand 33 with a prescribed force, and as shown in this drawing, it comprises a contact pressure generator 35 a , a connecting rod member 35 b , a contact pressure transmitting member 35 c to the shaving material and an anchoring member 35 d , and it is positioned and anchored on the mounting frame 39 ( 39 c ) via the anchoring member 35 d .
  • An example of the contact pressure applying means 35 is a fluid pressure working cylinder as shown, which works by fluid pressure such as compressed air pressure or oil pressure.
  • the invention is not necessarily limited to the embodiment shown in FIG.
  • any apparatus which allows the prescribed contact pressure to be applied to the contact plane A of the blade stand 33 with the shaving material 31 may be suitably used.
  • an apparatus which grips and transports the shaving material 31 with a pair of belts or rolls may be used as a well-known transport apparatus allowing continuous or intermittent feeding.
  • the driving means 36 comprises rotary driving means which drives rotation of the blade stand 33 , and it includes a driving apparatus 36 a such as a hydraulic motor or electric motor as the motive power source, a driving end motive power transmitting member 36 b , a motive power propagating member 36 c , a passive end motive power transmitting member 36 d , a rotary driving axis 36 e , a bushing 36 f and an anchoring member 36 g for the bushing 36 f .
  • the driving apparatus 36 a and the anchoring member 36 f are each positioned and anchored on the mounting frame 39 b .
  • the passive end motive power transmitting member 36 d is attached to one end of the rotary driving axis 36 e while the blade stand 33 is attached at the other end thereof, and pivots in a freely rotatable manner at its center by the bushing 36 f.
  • the blade stand 33 attached to the other end of the rotary driving axis 36 e is driven to rotate.
  • the motive power transmitting members 36 b and 36 d there may be mentioned a toothed pulley, V-belt pulley, gear or the like
  • the motive power propagating member, 36 c there may be mentioned a toothed belt (timing belt), V-belt, chain, intermediate gear or the like.
  • One or more shaving blades 34 (shown in this drawing as shaving blades 34 a and 34 b ) whereby the shaving material 31 is shaved to obtain ultrashort-cut fibers are provided on the blade stand 33 in a radial fashion from the center of rotation toward the direction of the radius, so that when the shaving blade 34 is driven to rotate with the blade stand 33 , the shaving material 31 contacting with the blade stand 33 is shaved by the shaving blade 34 .
  • the rotating speed of the blade stand 33 is preferably freely variable to match the nature of the shaving material 31 , and for example, it may be freely adjustable to 0.05-1500 rpm.
  • the rotation speed variation may be accomplished, for example, by controlling the frequency with an inverter, with the driving apparatus 36 a as an alternating current motor such as an induction motor or synchronous motor, as is well known, by controlling the supplied pulse number, with the driving apparatus 36 a as a pulse motor, or by providing a driver apparatus whereby the frequency is controlled by chopping a direct current, with the driving apparatus 36 a as a direct current motor.
  • the embodiment described in detail above relates to an apparatus whereby the shaving blade 34 is rotated and the shaving material 31 is contacted with the shaving blade 34 to obtain ultrashort-cut fibers, but as an opposite mode, the shaving blade 34 may be anchored and the shaving material rotated and contacted with the shaving blade 34 to shave ultrashort-cut fibers. Also, the shaving blade 34 or shaving material 31 may be moved in a back-and-forth linear fashion instead of rotational motion of the shaving blade 34 or shaving material 31 .
  • the essential aspect is that the shaving blade 34 and the shaving material 31 containing the fiber bundle 31 a are in relative motion in the shaving direction, whereby the shaving edge of the fiber bundle 31 a is thinly shaved.
  • the shaving material 31 is shaved to produce ultrashort-cut fibers.
  • This “shaving embodiment” will now be explained in detail with reference to FIG. 15 .
  • FIG. 15 is a magnified front cross-sectional view of the essential part (shaving section), of FIG. 14 , and in FIG. 15 , the shaving material 31 consists of a fiber bundle 31 a embedded in an embedding material 31 b as already explained above.
  • the fiber bundle 31 a is composed of numerous paralleled individual filament groups, and the overall size of the fiber bundle 31 a is between 10,000 and 10 million dtex.
  • the total length of the fiber bundle 31 a used here does not necessarily have to be limited, but in consideration of workability and productivity, as well as ease of embedding, it is preferably between 5 and 1000 mm. In the example of FIG.
  • the fiber bundle 31 a cut to the prescribed length is embedded in an embedding material 31 b in a separate step from the shaving step and then shaved by batch processing, but the shaving may also be carried out continuously, whereby the fiber bundle 31 a composed of continuous individual filament groups is continuously embedded in the embedding material 31 b.
  • the embedding material 31 b in the interior of the fiber bundle 31 a is not shown in FIG. 15 , it should be noted that the embedding material 31 b is naturally present, though in a small amount, in the interior of the fiber bundle 31 a as already explained with the details of the embedding treatment. Particularly as the overall size of the fiber bundle 31 a increases, the individual filament groups composing the fiber bundle 31 a will tend to move toward the direction in which the shaving blade 34 a moves during shaving (the direction of the white arrow in FIG. 15 ), and therefore in order to prevent them from slipping under the shaving blade 34 a it is necessary to bind their freedom of movement by the embedding material 31 b.
  • the shaving blade 34 provided on the blade stand 33 can be freely adjusted to protrude only by the protrusion length C from the contact plane A of the blade stand 33 .
  • the protrusion length C may be freely adjusted to a height of less than 1 mm, and preferably 0.001-0.1 mm.
  • the contact pressure transmitting member 35 c forming part of the contact pressure applying means 35 can thus produce a condition wherein the shaving edge of the shaving material 31 is constantly pressed against the contact plane A of the blade stand 33 at the prescribed contact pressure.
  • the shaving blade 34 provided on the blade stand 33 will allow ultrashort-cut fibers having fiber lengths of between 0.005 mm and 1 mm (especially fiber lengths between 0.005 mm and 0.1 mm) to be shaved from the shaving material 31 according to the adjusted protrusion length C.
  • the thickness of the shaving blade 34 used is a matter of design to be appropriately optimized depending on the nature of the shaving material 31 , but a thickness of 0.2-12.0 mm is suitable for use.
  • the protrusion length adjusting means 37 comprises a sliding member 37 a to which the shaving blade 34 is anchored, and an attachment member 37 b such as a hexagon socket bolt, with the members 37 a and 37 b mounted as shown in an opening Q provided in the blade stand 33 .
  • F is the sliding surface formed on the opening O of the blade stand 33 , on which the sliding member 37 a slides.
  • H is a long hole for free movement of the sliding member 37 a in the sliding direction when clamping of the attachment member 37 b is loosened.
  • G is a groove in which the bottom of the sliding member 37 a is fitted, and this groove is formed at the position shown in the opening O of the blade stand 33 along the direction of sliding of the sliding member 37 a.
  • the protrusion length adjusting means 37 of the invention has a construction according to the embodiment shown in FIG. 16 , loosening of the attachment member 37 b , such as a hexagon socket bolt, using a tool such as a hexagonal wrench allows the sliding member 37 a to slide freely in the direction of protrusion of the shaving blade 34 while being guided by the groove G.
  • the shaving blade 34 can be adjusted to the prescribed protrusion length C by tightening the attachment member 37 b with the protrusion length kept at the prescribed length C using a jig or the like.
  • one or more shaving blades 34 are provided on the blade stand 33 in the direction orthogonal to the plane of the paper, i.e. along the direction of the radius from the center of rotation (axial center of the rotary driving axis 36 e ).
  • the ultrashort-cut fiber production apparatus of the invention is used for shaving of a shaving material 31 to obtain ultrashort-cut fibers, as explained above, but prolonged shaving of the shaving material 31 can lead to gasification or liquefaction of the embedding material 31 b when the operating environment for shaving is at a temperature higher than the solidifying temperature of the embedding material 31 b , thereby preventing it from exhibiting its function. For this reason, it is necessary to provide insulating means (not shown) in the holding means 32 holding the shaving material, or cooling means (not shown) when insulating means alone is not sufficient, for adequate cold insulation to prevent gasification or liquefaction of the embedding material 31 b .
  • a preferred mode for achieving this object is to locally cool the periphery of the shaving material 31 or to cool the entire shaving apparatus.
  • cooling means is preferably provided for cooling of the shaving material according to the invention when the shaving material is shaved. Even if the shaving process is carried out under temperature conditions at which the embedding material 31 b liquefies or gasifies, the cooling means cools the shaving material 31 to an appropriate temperature in order to maintain the embedding material 31 in a solid state with no phase conversion.
  • FIG. 17 is a simplified schematic configuration diagram showing an embodiment of a ultrashort cut fiber production apparatus according to the invention.
  • 61 61 a and 61 b
  • 62 62 a and 62 b
  • temperature sensors 62 a and 62 b
  • 64 represents a refrigeration unit.
  • the apparatus comprising the refrigerant pipes 61 , temperature sensors 62 , signal wires 63 , refrigeration unit 64 and temperature controlling means (not shown) constitutes the cooling means of the invention.
  • the cooling means is provided with, for example, the refrigeration unit 64 , and the refrigeration unit 64 is provided with a series of refrigerating devices such as a compressor, condenser and expansion valve as constituent elements.
  • a refrigerant such as a fluorocarbon, fluorocarbon substitute, isobutane, ammonia, ethylene glycol or alcohol is circulated and distributed through each of the refrigerant pipes 61 a and 61 b in a refrigeration cycle to allow cooling of the shaving material 31 or shaving blade 34 to the required cooling temperature.
  • low-temperature gasifying gas may be caused to adiabatically expand for cooling and the cooled low-temperature gasifying gas may be directly distributed through the refrigerant pipes 61 with the refrigerant.
  • a refrigerant such as brine may be subjected to primary cooling with the cooled low-temperature gasifying gas, and the primary cooled refrigerant such as brine may be circulated and distributed through the refrigerant pipes 61 for secondary cooling of the shaving material 31 and/or shaving blade 34 .
  • a well-known liquefied gas such as liquid nitrogen or liquid oxygen may be produced by an established process and used as the refrigerant for circulated distribution through the refrigerant pipes 61 .
  • FIG. 17 is an illustration of a system whereby the shaving blade 34 and the holding means 32 holding the shaving material 31 are cooling by contact with the refrigerant pipes 61 a and 61 b , but it will be readily imagined that a jacket may instead be provided around the exterior of the holding means 32 and the refrigerant circulated and distributed through the jacket.
  • a refrigeration room having its internal atmosphere cooled to the optimum temperature may be prepared for cooling of the entire shaving apparatus including the shaving material 31 and shaving blade 34 in the refrigeration room, or only the sections requiring cooling may be subjected to local cooling.
  • the shaving material 31 is cooled by cooling means according to the invention, and preferably the shaving blade 34 is simultaneously cooled together with the shaving material 31 , as already described.
  • increasing temperature of the shaving blade 34 due to friction with the shaving material 31 can have adverse effects such as blunting of the cutting edge of the shaving blade 34 , notable abrasion of the shaving blade 34 , or changes in the fiber lengths of the shaved ultrashort-cut fibers during shaving due to changes in the protrusion length of the shaving blade as a result of thermal expansion and the like.
  • the softness of the embedding material 31 b will produce a situation in which the fiber bundle 31 a cannot be firmly bound by the embedding material 31 b .
  • the hardness of the embedding material 31 b can be controlled by cooling the shaving material 31 by the aforementioned cooling means to achieve freezing to, for example, between 0° C. and ⁇ 100° C. This will allow the hardness of the embedding material 31 b to be controlled to create a condition where the freedom of movement of the fiber bundle 31 a is satisfactorily restricted by the embedding material 31 b .
  • the temperature suitable for freezing of the shaving material 31 will differ depending on the embedding material 31 b used, and therefore the final optimum temperature is preferably determined by experimentation with an actual shaving process.
  • the cooling temperature thus determined by experimentation is stored in the storage means of the temperature controlling means, comprising a microcomputer or the like not shown here, and is used to achieve cooling to the optimum state for the shaving material 31 or shaving blade 34 .
  • the temperature control is accomplished, for example, using a temperature sensor 62 a comprising a temperature sensing element such as a thermocouple mounted on the holding member 14 which holds the shaving material 31 , or using a similar temperature sensor 62 b mounted on the shaving blade 34 or on an anchoring member 5 anchoring it, to detect the temperature of the shaving material 31 and the shaving blade 34 , and using the detected temperature as the control variable for input to the temperature control means via interface means provided with a transducer or A/D (analog/digital) converter or the like.
  • the inputted detected temperature is used as the basis of feedback control of the refrigeration unit by an established method to keep the shaving material 31 or shaving blade 34 at the optimum temperature which is determined by experimentation as mentioned above.
  • the cooling means used for the invention is not restricted to the system described above employing a refrigerant, as other types of systems may also be used.
  • a different type of cooling system may be employed whereby cooling is accomplished utilizing a Peltier element such as illustrated schematically in FIG. 18 .
  • 65 is a Peltier element
  • 66 is a heat sink
  • 67 is electrical wiring for the Peltier element
  • 68 is a thermal insulating material.
  • this Peltier element 65 is an element which utilizes the “Peltier effect” to convert electric power to heat energy by flowing a current between elements, whereby it can function for control of temperature.
  • thermoelectric transducer generally has a construction wherein a p-type thermoelectric transducer and an n-type thermoelectric transducer are alternately connected by electrodes while the electrode surfaces are gripped by an insulating material, and it offers the advantages of a simple construction and easy handling.
  • the Peltier element 65 having this feature in connection with the heat-releasing shaving blade 34 , it is possible to draw heat from the shaving blade 34 and release it from the heat sink, in order to eliminate generated heat energy from the shaving blade 34 .
  • This will allow the shaving blade 34 to be held at a constant temperature, and thus contribute to stable shaving performance of the shaving blade 34 .
  • the shaving blade 34 is preferably anchored to the anchoring member 37 via the thermal insulating material 68 , because this will render it thermally separate from the anchoring member 37 and allow control of the temperature of the shaving blade 34 to the prescribed temperature even using a Peltier element 65 with only medium cooling power.
  • the temperature control of the shaving blade 34 may be accomplished by inputting the temperature detected by the temperature sensor 62 b mounted on the shaving blade 34 to the temperature control means (not shown) through the signal wire 63 b , and conducting feedback control of the current supplied to the Peltier element via the electrical wiring 67 .
  • the shape of the shaving material 31 held by the holding means 32 is not limited to cylindrical, and may be any other shape such as square columnar, hexagonal columnar, oblong columnar or the like, or even columnar with a donut-shaped lateral cross-section.
  • the shape will depend on the conditions during embedding treatment of the fiber bundle 31 a by the embedding material 31 b .
  • the shape of the shaving material 31 will be governed by the shape of the pot. It will also differ depending on the conditions of the holding member 32 a of the holding means holding the shaving material 31 .
  • the shaving edge of the shaving material 31 is constantly pressed at a prescribed contact pressure against the contact plane A formed on the top side of the blade stand 33 for shaving with the shaving blade 34 a
  • the following embodiment may also be employed.
  • the shaving material 31 is forcefully fed against the shaving blade 34 a by the prescribed amount corresponding to the fiber length to be shaved from the shaving material 31 , for shaving with the shaving blade 34 a , instead of pressing the shaving edge of the shaving material 31 at a prescribed contact pressure against the contact plane A formed on the top side of the blade stand 33 .
  • the shaving material 31 is again forcefully fed against the shaving blade 34 a by the prescribed amount corresponding to the fiber length to be shaved from the shaving material 31 , before the next shaving begins for shaving with the shaving blade 34 a , and this procedure is repeated.
  • the apparatus of the invention is provided with feeding means for intermittent feeding of the shaving material against the shaving blade 34 a by a prescribed amount corresponding to the fiber length to be shaved.
  • the feeding means there may be employed a well-known technique commonly used in shaving machine tools for feeding the shaving blade 34 a and/or the shaving material 31 by a prescribed amount. The detailed explanation thereof will be omitted here.
  • a holder which firmly holds the shaving material 31 without slipping.
  • the holder is attached to a shaft having a helical feed groove.
  • This is well-known intermittent feeding means whereby rotation of the shaft by a prescribed rotation angle allows the shaving material 31 to be intermittently fed against the shaving blade 34 a by the prescribed amount.
  • a servo motor such as a pulse motor may be used for rotation of the shaft by the prescribed rotation angle.
  • the shaving edge is contacted with the shaving blade 34 a between shavings, instead of constantly contacting the shaving edge of the shaving material against the contact plane A of the blade stand 33 , thereby offering an advantage whereby the shaving edge of the shaving material 31 is less affected by vibration of the blade stand 33 or the shaving blade 34 a generated by friction or during shaving.
  • FIGS. 19 and 20 are schematic illustrations showing production of ultrashort-cut fibers according to the invention.
  • shaving of the shaving material 31 is preferably carried out while holding the shaving material 31 with the holding means 32 at a position close to the shaving blades 34 .
  • This will make it possible to avoid deformation of the embedding material 31 b by impact force during the shaving as occurs with ice or dry ice, or concentration of the force during shaving on the anchor section, for materials prone to damage. Therefore, it is essential for the holding means 32 performing this role to be provided with the function of supporting or holding the shaving blade 34 which moves relative to the shaving material 31 in the direction indicated by the white arrow in the drawing.
  • the holding means 32 performs the role of distributing and absorbing the force acting on the shaving material 31 at a position close to the shaving blades 34 during shaving.
  • the holding means 32 may also consist of a jig such as a guide plate which contacts with the shaving material 31 , so that it does not completely hold the shaving material 31 but rather supports the shaving material 31 from the direction opposite to the direction of the shaving force acting on the shaving material 31 .
  • the member holding and anchoring the shaving material 31 may be a known chuck so long as it can satisfactorily hold and anchor the shaving material 31 . However, if it is desired to more firmly grip and anchor the shaving material 31 , the lower end of the fiber bundle 31 a forming part of the shaving material 31 may be solidified with a resin such as an adhesive, and the resin section held and anchored.
  • ultrashort-cut fibers are produced by shaving the edge F of a shaving material 31 composed of embedded fiber bundles
  • apparatuses for shaving of the shaving material include apparatuses with shaving mechanisms employed in known machine tools such as planing machines, slotting tools, planing/molding machines and millers.
  • machine tools such as planing machines, slotting tools, planing/molding machines and millers.
  • the mechanisms or constructions of such known machining tools may also be partly modified.
  • the workpiece (according to the invention, this is the “shaving material 31 comprising the fiber bundles 31 a embedded in the embedding material 31 b ”) mounted on the working bench is a single continuous block, as is the case when planing a rail, for example, but according to the present invention, a plurality of individual independent shaving materials 31 must be situated in an array in the direction of planing. According to the invention, however, a plurality of shaving materials 31 may even be set in parallel in a dense state and embedded in the embedding material, thereby forming a single block which may be supplied to the working bench.
  • FIG. 19 shows an embodiment wherein numerous shaving materials 31 are set in an array on the working bench, and the edges F of the fiber bundles 31 a embedded in the embedding material 31 b are shortly shaved by shaving the shaving materials 31 to obtain ultrashort-cut fibers.
  • FIG. 19 shows an example with column 1 (R 1 ) to column 16 (R 16 ) in the horizontal direction and row 1 (L 1 ) to row 8 (L 8 ) in the vertical direction for a total of 128 (8 ⁇ 16) shaving materials 31 set on a working bench, but the invention is naturally not restricted to this number or arrangement so long as the gist of the invention is satisfied.
  • the group of shaving materials 31 forming the shaving edges F which are orthogonal to the lengthwise direction of the fibers are set so that all of the shaving edges F are level. This is because the shaving edges F become leveled when at least one of the shaving blades 34 shaves a group of shaving materials 31 .
  • the shaving edges F do not necessarily have to be leveled before planing of the shaving materials 31 begins. Even if uneven shaving edges F are formed before planing, rough cutting of the shaving edges F can be carried out to produce a horizontal surface from the shaving edges F of the shaving material 31 . Still, the rough cut sections will have uneven shaven fiber lengths, and must therefore be removed before the actual planing so that they do not mix with the ultrashort-cut fiber products.
  • a plurality of shaving materials 31 are prepared and set on the working bench (not shown) in the array shown in FIG. 19 , simultaneous shaving of the edges F of the shaving materials 31 will naturally result in a major improvement in ultrashort-cut fiber yield compared to shaving individual shaving materials.
  • the plurality of shaving materials 31 may also be set in an arrangement without spaces, and a group of the plurality of shaving materials 31 in a dense array may be embedded in an embedding material filling the spaces between each of the individual shaving materials 31 and integrated, to obtain a “new shaving material”.
  • the “new shaving material” may be subjected to planing using a known planing machine to mass produce ultrashort-cut fibers having ultrashort-cut fiber lengths of 0.005-1.0 mm.
  • FIG. 19 shows an example of mass production of ultrashort-cut fibers by aligning a plurality of shaving materials 31
  • efficiency of the ultrashort-cut fiber production can be improved by setting up an array not only of a plurality of shaving materials 31 but rather of a plurality of shaving blades 34 , as with the embodiment shown in FIG. 20 .
  • FIG. 20 ( a ) is schematic front view and FIG. 20 ( b ) is a schematic side view.
  • the plurality of shaving materials 31 is shaved at once by shaving blades 34 set on sixteen (4 ⁇ 4 in the longitudinal and lateral directions) blade stands 33 , to accomplish mass production of ultrashort-cut fibers.
  • the degree of protrusion of the shaving blades 34 with respect to the shaving materials 31 is adjusted, however, for movement of the shaving blades 34 in the lateral direction, or in the direction indicated by the white arrow as shown in FIG. 20 ( b ).
  • the shaving blade 34 which shaves the shaving material 31 at position R 7 is formed to protrude toward the shaving materials 31 , with respect to the shaving blade 34 which shaves the shaving material 31 at position R 8 , by an amount corresponding to the intended fiber length of the ultrashort-cut fibers.
  • the same relationship applies for the shaving blades 34 which shave the shaving materials 31 at positions R 9 and R 10 in FIG. 20 ( b ).
  • an individual filament group made of polyester was bound into a 2 million dtex fiber bundle, and the fiber bundle was immersed in a potassium filled with water and frozen to obtain a shaving material with ice as the embedding material.
  • the shaving edge of the obtained shaving material 31 was cut with a rotary cutter having a circular cutting blade to produce a (75 mm ⁇ 40 mm length cylindrical shaving material 31 having clean shaving edges.
  • the same type of apparatus shown in FIG. 14 was used to clamp the shaving material 31 with a clamping member comprising a pair of half cylinders.
  • the clamping member forming part of the holding means 32 was surrounded by a jacket through which a refrigerant (brine) circulated, so that the holding means 32 was cooled to ⁇ 4° C.
  • an air cylinder with a ⁇ 50 mm cylinder diameter and a 100 mm stroke length was employed as contact pressure applying means 35 and compressed air at 0.11 MPa was fed to the air cylinder to press the shaving material 31 against the contact plane A of the blade stand 33 .
  • the rotation driving axis (blade stand 33 ) was also rotated at 30 rpm by a reduction gear-equipped inverter motor via a timing belt.
  • the shaving blade 34 used was high speed steel with a thickness of 0.25 mm, a blade mounting angle of 25° and a back angle of 30°.
  • the protrusion length of the shaving blade 34 was adjusted to 0.02 mm for shaving, yielding ultrashort-cut fibers with fiber lengths of 0.025 mm. After eliminating the water from the obtained ultrashort-cut fibers, they were dried in a conventional hot air drier using hot air at 120° C. The shaved ends of the dried ultrashort-cut fibers were clean, with virtually no miscut short fibers.
  • Ultrashort-cut fibers obtained by the production process of the invention are shaved to fiber lengths of 0.005 mm to 1 mm, and especially 0.005 mm to 0.1 mm, and therefore they are expected to have a wide range of uses including, for example, use in paints by inclusion of ultrashort optical interference fibers in an adhesive such as described in Japanese Unexamined Patent Publication HEI No. 11-241223, use by inclusion in cosmetic products, or use for flock working or as a printer toner material.
  • the production apparatus of the invention can easily and stably produce ultrashort cut fibers having fiber lengths of 0.005 mm to 1 mm, and especially 0.005 mm to 0.1 mm, while drastically reducing miscut fibers, and therefore provides satisfactory product yields to allow production of ultrashort-cut fibers on an industrial scale.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Preliminary Treatment Of Fibers (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
US10/566,177 2003-08-04 2004-07-30 Method and device for manufacturing extremely short fiber Abandoned US20060225252A1 (en)

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JP2003285617 2003-08-04
JP2003-336937 2003-09-29
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PCT/JP2004/011289 WO2005012607A1 (fr) 2003-08-04 2004-07-30 Procede et dispositif permettant de fabriquer des fibres extremement courtes

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US20110143089A1 (en) * 2007-07-26 2011-06-16 Snecma Mechanical component comprising an insert made of composite
US20120305622A1 (en) * 2011-06-01 2012-12-06 Truetzchler Gmbh & Co.Kg Device on a spinning room preparation machine, for example a fibre flock feeder, carding machine, cleaner or the like, for supplying and/or discharging fibre material
JP2020037750A (ja) * 2018-09-03 2020-03-12 株式会社リコー 繊維集合体、短繊維及びその製造方法、並びに膜及びその製造方法
CN111139556A (zh) * 2020-02-26 2020-05-12 江苏奥神新材料股份有限公司 一种用于聚酰亚胺纤维切断的设备及切断方法
EP3375609B1 (fr) 2017-03-14 2021-02-17 Ricoh Company, Ltd. Poudre de résine pour fabrication de forme libre solide et dispositif de fabrication d'un objet de fabrication de forme libre solide
EP3375608B1 (fr) 2017-03-17 2021-05-05 Ricoh Company, Ltd. Poudre de résine pour la fabrication de forme libre solide et dispositif pour un objet de fabrication de forme libre solide
EP3482900B1 (fr) 2017-11-09 2021-06-09 Ricoh Company, Ltd. Particule pour fabrication de formes libres solides
EP3616869B1 (fr) 2018-08-31 2021-06-16 Ricoh Company, Ltd. Poudre de résine, ainsi que dispositif et procédé de fabrication d'un objet de forme libre solide utilisant ladite poudre
EP3482901B1 (fr) 2017-11-09 2021-08-04 Ricoh Company, Ltd. Poudre de résine pour la fabrication de forme libre solide
EP3524430B1 (fr) 2018-02-07 2021-12-15 Ricoh Company, Ltd. Poudre pour la fabrication de formes libres solides, et procédé de fabrication de formes libres solides
CN114108146A (zh) * 2022-01-28 2022-03-01 江苏九九久科技有限公司 一种耐热超高分子量聚乙烯纤维制品的制备装置
EP3620283B1 (fr) 2018-09-07 2022-03-30 Ricoh Company, Ltd. Poudre de résine, et procédé et dispositif de fabrication d'un objet de forme libre solide en utilisant ladite poudre
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US20100291339A1 (en) * 2007-07-26 2010-11-18 Snecma Mechanical component comprising an insert made of composite
US20110143089A1 (en) * 2007-07-26 2011-06-16 Snecma Mechanical component comprising an insert made of composite
US8920935B2 (en) 2007-07-26 2014-12-30 Snecma Mechanical component comprising an insert made of composite
US9127337B2 (en) * 2007-07-26 2015-09-08 Snecma Mechanical component comprising an insert made of composite
US20120305622A1 (en) * 2011-06-01 2012-12-06 Truetzchler Gmbh & Co.Kg Device on a spinning room preparation machine, for example a fibre flock feeder, carding machine, cleaner or the like, for supplying and/or discharging fibre material
US8621721B2 (en) * 2011-06-01 2014-01-07 FA. Truetzschler GmbH & Co. KG Device on a spinning room preparation machine, for example a fibre flock feeder, carding machine, cleaner or the like, for supplying and/or discharging fibre material
EP3375609B1 (fr) 2017-03-14 2021-02-17 Ricoh Company, Ltd. Poudre de résine pour fabrication de forme libre solide et dispositif de fabrication d'un objet de fabrication de forme libre solide
EP3375608B1 (fr) 2017-03-17 2021-05-05 Ricoh Company, Ltd. Poudre de résine pour la fabrication de forme libre solide et dispositif pour un objet de fabrication de forme libre solide
EP3482900B1 (fr) 2017-11-09 2021-06-09 Ricoh Company, Ltd. Particule pour fabrication de formes libres solides
EP3482901B1 (fr) 2017-11-09 2021-08-04 Ricoh Company, Ltd. Poudre de résine pour la fabrication de forme libre solide
US11504883B2 (en) 2017-11-13 2022-11-22 Ricoh Company, Ltd. Resin particle producing method
EP3524430B1 (fr) 2018-02-07 2021-12-15 Ricoh Company, Ltd. Poudre pour la fabrication de formes libres solides, et procédé de fabrication de formes libres solides
EP3616869B1 (fr) 2018-08-31 2021-06-16 Ricoh Company, Ltd. Poudre de résine, ainsi que dispositif et procédé de fabrication d'un objet de forme libre solide utilisant ladite poudre
JP2020037750A (ja) * 2018-09-03 2020-03-12 株式会社リコー 繊維集合体、短繊維及びその製造方法、並びに膜及びその製造方法
JP7163676B2 (ja) 2018-09-03 2022-11-01 株式会社リコー 繊維集合体、短繊維及びその製造方法、並びに膜及びその製造方法
EP3620283B1 (fr) 2018-09-07 2022-03-30 Ricoh Company, Ltd. Poudre de résine, et procédé et dispositif de fabrication d'un objet de forme libre solide en utilisant ladite poudre
CN111139556A (zh) * 2020-02-26 2020-05-12 江苏奥神新材料股份有限公司 一种用于聚酰亚胺纤维切断的设备及切断方法
CN114108146A (zh) * 2022-01-28 2022-03-01 江苏九九久科技有限公司 一种耐热超高分子量聚乙烯纤维制品的制备装置

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TW200508436A (en) 2005-03-01
KR20060120577A (ko) 2006-11-27
JP4435738B2 (ja) 2010-03-24

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