Method for producing releasable buckled crimped yarn cake, apparatus for producing the same, and releasable buckled crimped yarn cake

Abstract

[Summary] The present invention provides a compact package of buckled crimp yarn having high bulkiness, an inexpensive and safe manufacturing method thereof, and a manufacturing apparatus therefor. That is, it is possible to produce a releasable buckled crimp fiber cake from a high-speed extruded fiber using simple equipment without winding. Since buckled crimp is imparted to said spinning fiber at the same time as solidification, a robust and bulky crimp is imparted. Moreover, since the fiber is compressed into a cake shape in a filament-opened state, compactness of packages and bulkiness of the opened filaments are achieved all at once. Meanwhile, in a traditional buckled crimp imparting method, the crystal structure of a fiber once fixed in a flat yarn state tends to remain, and it is difficult to improve its bulkiness and fastness. Since a winder is not used in the present invention, the equipment is simple, and it is easy to produce many kinds of product in small quantities. Further, in the package according to the present invention, since fibers are laminated in a columnar shape and can be divided along the lamination surface at an arbitrary portion, there is no need for rewinding for subdividing the package. Incidentally, although flat yarn cannot be obtained by the method of the present invention, the versatility of the resulting fiber is not impaired due to the fact that it is inherently crimped, as is the case with wool and cotton yarn. [Problems] With conventional technology, obtaining buckled crimp yarn from a spinning raw material required tedious processes such as spinning, winding, unwinding, buckled crimp processing, and rewinding. In other words, winding requires a high-speed winder and an associated automatic package switching device, and it was not easy to create an inexpensive and safe facility, or to create a facility that is flexible enough to be suitable for small-lot, high-mix production. Moreover, a fiber that has been drawn using rollers goes through a process where it is temporarily fixed as flat yarn. Therefore, even if it is later buckled crimped, the resultant final product is likely to revert to a crystalline structure that was created on the way of the process, making it difficult to obtain a fiber with a robust buckled crimp in terms of yarn quality. Furthermore, with conventional spool-type packages, it is difficult to achieve both compactness of packages and bulkiness of released yarn. [Solution] A fiber-forming fluid is extruded from a spinneret and ejected with a pressurized gas through a narrow hole positioned opposite to the spinneret; and the resultant fiber is made into a rod of fiber having a buckled crimp in a crimping zone provided at the end of said narrow hole; and the rod of fiber is sent and accumulated into a compressing chamber comprising a reverse funnel-like section and a hollow cylindrical section, and a releasable buckled crimp yarn cake is produced by vibrational compression from the downstream side of said compressing chamber.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a cake of buckled crimp yarn (also known as stuffed crimp yarn), an apparatus therefor, and a releasable buckled crimp yarn cake obtained by the method. Here, "releasable" means that yarn can be continuously pulled apart from a cake by pulling the end of the yarn apart and, at the same time, adjusting tension with or without a guide. The manufacturing method of the present invention can achieve fiber forming from a fiber forming fluid, imparting buckled crimp, and conducting compression into a cake all at once. Said buckled crimp yarn is formed into a cake in a filament-separated state, so the resultant released yarn is fiber-opened and extremely bulky. Furthermore, the cake of the present invention is columnar and can be divided in a direction perpendicular to the axis, so there is no need to rewind it in dividing it into smaller pieces. In other words, extremely small packages can be produced easily. In addition, since no high-speed rotating body is used in packaging, it is easy to independently change packaging conditions for each apparatus, making the present method suitable for small-lot, high-mix production. The fiber obtained in the present invention is not subjected to an independent drawing step (by rollers), and therefore does not have high strength, but, when relaxed, does not revert to its state before a buckled-crimping processing and has excellent dimensional stability. In the method of the present invention, although a flat yarn cannot be produced, the inherent crimping of the fiber does not impair its versatility, as in the case of wool or cotton yarn.[Background Art]

[0002] Currently, a method is known in which a winder is used to spin at a high speed, for example, at 5,000 m / min or more, to obtain a fiber that does not require additional drawing. Furthermore, it is not difficult to pull an extruded fiber at a speed of 6,000 m / min or more by passing it through a pressurized gas chamber as described in Patent Documents 1 and 2, or at a speed of 5,000 m / min or more by using a suction gun (in this description, the suction gun refers to a device that has a function of pulling a fiber in atmospheric pressure environment. In other words, the suction gun method in this description does not include the above-mentioned pressurized gas chamber method) as described in Patent Document 3. In either case, however, if such an extruded fiber is to be directly packaged, a high-speed winder is required, which requires high safety considerations and high cost. Furthermore, the yarn obtainable by the high-speed winding directly connected to spinning is flat yarn. Under such circumstances, if a crimping process is to be interposed along the way, significant speed reduction is unavoidable. Meanwhile, if the crimping processing is to be performed separately on the flat yarn obtained by high-speed winding, rewinding is required, which inevitably leads to a significant increase in costs.

[0003] Against that, there are also known methods in which a fiber is first extruded into the atmosphere by a pressurized gas chamber method and then compressed into a cake-like package (Patent Document 4), or in which a fiber is buckled and crimped directly after spinning using a pressurized gas chamber method to form a buckled crimp fiber rod (Patent Document 5), and then this buckled crimp fiber rod is made into a spirally stored package (Patent Document 6). However, in the former (Patent Document 4), there are some disadvantages. That is, since there is no buckled crimp process, the crimping property of the resulting fiber is not high. Moreover, its compression device structure is not simple and is not practical. Meanwhile, in the latter (Patent Document 5), the package is easy to collapse, and it is difficult to make the density of the package high. The present invention overcomes these problems of the prior art and makes it possible to manufacture a compressed package of buckled crimp fiber directly after spinning using a simple method and device.[Prior Art References][Patent References]

[0004] Patent Reference 1 : Specification of U.S. Patent No. 3,707,593 Patent Reference 2 : Specification of British Patent No. 1574464 Patent Reference 3 : Japanese Patent Application Laid-Open Publication Hei 1-117179 Patent Reference 4 : Japanese Patent Application Laid-Open Publication Sho 52-96222 Patent Reference 5 : Japanese Patent Application Laid-Open Publication Sho 54-46924 Patent Reference 6 : Japanese Patent Application Laid-Open Publication Sho 55-98061 [Summary of the Invention][Problem to be Solved by the Invention]

[0005] The present invention provides a buckled crimp yarn cake having high bulkiness, an inexpensive and safe manufacturing method thereof and a manufacturing apparatus therefor.

[0006] In conventional technology, obtaining buckled crimp yarn from spinning raw materials required tedious processes such as spinning, winding, unwinding, buckled crimp processing (also known as stuffed crimping), and rewinding. This means that winding requires apparatuses such as a high-speed winder and an automatic package switching device that can be applied to the winder, making it difficult to make inexpensive and safe equipment, nor to make equipment that is flexible and suitable for small-lot, high-mix production. Furthermore, the fiber that has undergone a roller-drawing process undergoes a process in which its structure is once fixed as flat yarn. Therefore, even if it is subsequently buckled crimped, the resultant final product is prone to revert to its crystalline structure before the processing (i.e., it is prone to return to its state before the processing), making it difficult to obtain a fiber with a robust buckled crimp in terms of yarn quality. Furthermore, with conventional spool-type packages, it is difficult to achieve both compactness of the package and bulkiness of released yarn.

[0007] In other words, conventionally, although a winder was usually used to produce fiber packages from fiber forming raw materials, a high-speed rotating body, which requires significant safety considerations and high equipment costs, was used at a high winding speed, in which additional drawing is unnecessary, as the winder. Furthermore, the resulting yarn so obtained is usually flat yarn. Although it is possible to wind semi-oriented yarn such as POY (partially oriented yarn) and then further draw the yarn and, at the same time, subject it to a crimping process, a rewinding process is necessary, increasing a production cost. In light of these issues, the present invention produces a releasable buckled crimp yarn cake by directly depositing high-speed extruded yarn. Because said buckled crimp yarn is formed into a cake in a filament-separated state, the released filaments are opened and extremely bulky. Furthermore, since the cake of the present invention is columnar and can be split perpendicularly to its axis, no rewinding is necessary in splitting the package for use. Furthermore, because no high-speed rotating body is used during the cake formation process, it is easy to set independently operation conditions for each apparatus, making the present invention suitable for small-lot, high-mix production.[Means for Solving the Problems]

[0008] Manufacturing a releasable buckled crimp yarn cake is characterized by; extruding a fiber forming fluid from a spinneret into a fiber, ejecting the fiber with a pressurized gas through a narrow hole positioned opposite to the spinneret; making the fiber into a rod of fiber having a buckled crimp in a crimping zone provided at the end of said narrow hole, sending and accumulating the rod of fiber into a compressing chamber comprising a reverse funnel-like section and a hollow cylindrical section, and making the resultant accumulated rod of fiber into a cake from the downstream side of said compressing chamber, with the rod vibration-compressed.[Effect of the Invention]

[0009] In the method of the present invention, a rotating body is not necessary for packaging, so no large-scale equipment is required, and risks associated with speed-up are small, making it possible to produce a releasable buckled crimp yarn cake directly from a spinning material at a high speed. Meanwhile, since it is easy to change operation conditions for each apparatus, the method is suitable for small-lot, high-mix production. Furthermore, the fiber obtained by this invention, in which a strong buckled crimp and indentations remain, has excellent dimensional stability. Although it differs from flat yarn or false-twisted yarn, this does not impair the versatility of the fiber, as is the case with wool or cotton yarn.[Embodiments for Carrying Out the Invention]

[0010] In the present invention, a spinning dope that can be used for melt spinning or dry-wet spinning is used as a fiber forming fluid. The spinning dope needs to be solidified while picked up together with a high-speed fluid. Therefore, use of the dope that can be used for melt spinning is advantageous. The reasons for this are that it can be rapidly solidified by rapid cooling or pulling and that there is little exchange of solvent between the spinning dope and the high-speed fluid. Examples of the melt-spinnable dope include thermoplastic resin fiber materials such as polyolefin-based resins, polyamide-based resins, polyester-based resins, polyether ketone, polyether ether ketone, polyether sulfone, polyphenylene sulfide, thermoplastic polyether imide, and thermoplastic fluorine-based resins. Specifically, said material is preferably polyester-based, polypropylene-based, polyamide-based, polyethylene-based, or a combination thereof. Particularly preferred are polyester-based materials such as polyethylene terephthalate-based, polyethylene naphthalate-based, and polybutylene terephthalate-based materials, and polyamide-based materials such as nylon 6-based and nylon 66-based material. Said combination thereof includes composite spinning and blend spinning or the like. However, the materials used in such a combination are prone to yarn breakage when picked up at a high speed. Therefore, preferred combinations are limited.

[0011] There are two methods for taking up a fiber together with a high-speed fluid, with the fiber solidified: One is to extrude a spinning dope from a spinneret into a pressurized gas chamber and then eject it out from a narrow hole located at the opposite side of the spinneret together with the pressurized gas; the other is to once extrude a spinning dope into open air, then suck the resultant solidified fiber into a narrow hole with a suction gun and eject it out from the opposite side of the narrow hole together with the pressurized gas.

[0012] The method using a pressurized gas chamber is suitable for high-speed pickup. Moreover, because strong pulling force is exerted in the pressurized fluid atmosphere, it is easy to obtain highly oriented, low-elongation fibers all at once. For example, even with polyethylene terephthalate, which is relatively difficult to orient, it is not difficult to achieve a spinning speed of around 6,000 m per minute and a fiber elongation of around 40% at an air pressure of 2 to 3 atmospheres. Furthermore, it is even possible to achieve a spinning speed of over 8,000 m per minute. Still furthermore, this method allows an extruded fiber to be buckled and crimped at a relatively high temperature. Therefore, this makes it easy to obtain a highly processed crimped fiber.

[0013] On the one hand, in the method, it is possible to pick up polyethylene terephthalate at a speed in which no additional drawing is required, for example, at 5,000 m per minute or more, with a high-performance suction gun. Since the suction gun can be operated in the atmosphere, use of the gun has a greater freedom for, for example, a countermeasure against thread breakage. Furthermore, the suction gun has an advantage in which an air flow around a spinneret is insusceptible to any outer wall, making it easier to reduce thread sway and thread breakage.

[0014] Meanwhile, unless there is no care about direct spin-cake formation, any fiber that has been wound up by a traditional method can be used as a raw material, and then ejected out with a pressurized gas from a narrow hole using a suction gun, followed by subsequent cake formation in the same manner as a method using a pressurized gas chamber. In this case, although there are differences in quality and cost in these two methods, a wide range of materials that are not suitable for direct spin-cake formation can be used in the suction gun method.

[0015] For economical and safe reasons, pressurized air is generally used as a high-velocity fluid after adjusting the temperature of the air to a moderate level. Heated steam can also be used alone or in a mixture with air, but a countermeasure against condensation mist is required and it may be difficult to use it with a spinning material that has a low solidification point.

[0016] Hereunder, for the time being, to make the explanation simple, the following description will be based on a pressurized gas chamber method using air as a gas and a melt-spinnable polymer as a spinning dope, with reference to reference numerals in the attached drawings. However, the technical concept of the present invention can be applied to both a ready-made fiber and a suction gun method, and the following examples are not intended to limit the interpretation of the claims of the present invention in any way.

[0017] A pressurized gas chamber (3) smoothly converges at the opposite end of a spinneret (1) and connects to a narrow hole (6), and an extruded fiber is ejected at a high speed together with a pressurized air from the open end of the narrow hole (6). The narrow hole desirably has a smooth wall, and its diameter is desirably 2 to 5 mm, preferably 2.5 to 4 mm, and more desirably 2.5 to 3.5 mm, and its length is desirably 50 to 500 mm, preferably 70 to 300 mm, and more desirably 100 to 200 mm.

[0018] If the diameter of the narrow hole is less than 2 mm, there is a risk of hole clogging in the event of yarn breakage. Meanwhile, if the diameter is 5 mm or more, problems may arise such as not only does the effect of increasing a pick-up speed saturate but the amount of compressed air becomes excessive, which is uneconomical and increases noise and causes the air flow in the pressurized air chamber to easily become turbulent and as a result, easily causes yarn breakage. Although the preferred diameter of the narrow hole depends on the thickness of an extruded fiber, a diameter of 2.5 to 4 mm is appropriate for manufacturing average filament yarn of approximately 50 to 500 deniers. Sudden fusion or yarn breakage of an extruded fiber occurs in some cases. However, with a narrow hole diameter of 2.5 mm or more, as long as such fusion or breakage is partial, an extruded fiber can continue to be picked up. Of course, such fusion or yarn breakage can cause fatal problems such as staining spots in clothing, but it is not necessarily fatal for bulky yarn used for wadding and bulky sheets.

[0019] It is possible to considerably increase a pick-up speed even with a narrow hole length of 50 mm or less. However, considering that even greater speed increase is possible with length longer than that, there is little benefit to actively using a narrow hole length of 50 mm or less. Meanwhile, if the narrow hole length exceeds 500 mm, the effect of increasing a pick-up speed saturates, so there is also little reason for actively using such a length. However, even if the narrow hole length exceeds 500 mm, e.g. a length of 1000 mm or 2000 mm, there is often no critical issue with regard to a pick-up speed, so it is also possible to substantially change the position of ejection, or to substantially change the direction of ejection, for example, by using a smoothly curved narrow hole.

[0020] The pressure in the pressurized gas chamber (3) is usually set at a gauge pressure of around 1 to 5 atmospheres. When the solidification point of a spinning dope is located as downstream as possible, i.e., near a narrow hole inlet, it is easier to maintain a high pick-up speed, and for this reason, a pressure of 2 to 4 atmospheres is used in most cases. However, said pressure will shift to lower if a spinning length (the distance from the spinneret (1) to the narrow hole (6) inlet) is longer, or if the discharge amount of a spinning dope is lower, or if air temperature is lower. However, it is not difficult to maintain a pick-up speed of around 4,000 m per minute even at a pressure below 1 atmosphere, and, depending on the type of polymer and application of an extruded fiber, such pressure can be sufficient to achieve a desired purpose. Meanwhile, a pressure above 5 atmospheres does not necessarily increase a pick-up speed, but may be preferable in the case for materials that require rapid cooling or for a high discharge amount.

[0021] Here, the solidification point of an extruded fiber means the position at which the extruded fiber can be picked up and at which inter-fiber fusion can be avoided during a buckled crimp processing stage. Therefore, in the present invention, disposing the solidification point of a spinning dope near the inlet of the narrow hole (6) means that the spinning dope solidifies near said inlet of the narrow hole (6), and that constituent fibers in the resulting package are not fused but are dispersed as single fibers. It is not easy to accurately define the temperature of a spinning dope at the solidification point because fusibility of the material used in the spinning dope often remains at a temperature not greater than the melting point of the material but not less than the secondary transition point of the material. However, it is easy to determine the conditions of ejection under which constituent fibers within the resulting package are dispersed as single fibers rather than in a parallel bundle state.

[0022] The pressurized gas chamber (3) is a pressure-resistant vessel, and is preferably hollow cylindrical. One end thereof is the spinneret (1), and the other end is funnel-shaped and connected to the narrow hole (6). Its length (from the spinneret (1) to the inlet of the narrow hole (6), i.e., spinning length) must be equal to or longer than the length from the spinneret (1) to the solidification point of a spinning dope to prevent fusion of an extruded fiber. As to the length from the spinneret (1) to the inlet of the narrow hole (6), concretely a length of 300 mm to 5000 mm is adopted in most cases, and preferably it is 500 mm to 2000 mm. However, since it is easier to increase a pick-up speed by positioning the solidification point of a spinning dope at the downstream end of the pressurized gas chamber (3), i.e., near the inlet of the narrow hole (6), it is desirable to keep the length of the pressurized gas chamber (3) as short as possible as far as no fusion of an extruded fiber occurs. Meanwhile, the solidification point of a spinning dope varies greatly depending on the discharge amount of the spinning dope, its solidification temperature, an air pressure, etc., and the spinning length is also changed significantly depending on these factors. In other words, if the discharge amount is large, or the solidification temperature of the spinning dope is low, or air pressure is low, it becomes necessary to increase the spinning length. For example, when it is desired to obtain polyester or polyamide filaments of about 150D-48F, a pressurized gas chamber (3) length of 500 to 1000 mm is often employed.

[0023] In the pressurized gas chamber (3), to prevent a spinning fluid from thread sway or thread breakage, compressed air and the spinning fluid must flow together and in good order at the time that they are guided to the narrow hole (6). To achieve this, the compressed air chamber desirably has a large cross-section. However, since there is a limit to this, the compressed air must be pre-rectified before being guided to said pressurized gas chamber (3). Specifically, a compressed air supply chamber is installed around the periphery of said pressurized gas chamber (3), and an annular air dispersion element is installed between the two and compressed air is uniformly dispersed in said pressurized air supply chamber before being supplied to said pressurized gas chamber (3). Said air dispersion element is a member that can provide minim resistance to the compressed air, such as a porous metal plate, a metal plate perforated with numerous micropores, or a laminated and bonded fine wire mesh.

[0024] It is experimentally preferable to install the air dispersion element on the downstream side of the compressed gas chamber, as this reduces yarn breakage. If it is installed upstream, a spinneret will be more susceptible to compressed air temperature. Moreover it is thought that the flow pattern of spinning fluid will be more likely to become turbulent as the compressed air, which has a high velocity, comes into contact with the spinning fluid flow, which has a low velocity.

[0025] Furthermore, it is desirable for said air dispersion element to have a large air dispersion area to maximize its rectification effect. Said element is an annular member that forms part of the wall of the pressurized air chamber (3), and its diameter cannot be changed much. Therefore, in order to increase the air dispersion area, its height must be increased. Specifically, taking into account the strength and processing precision of the element, it is often more desirable for the height to be 100mm rather than 50mm, and 200mm rather than 100mm. Doing so enhances the air dispersion effect and, at the same time, ensures natural air supply to the top of the compressed air chamber.

[0026] The buckled crimping of the fiber ejected from the narrow hole is achieved by guiding the fiber ejected from the narrow hole (6) into a narrow, breathable passage. The narrow passage is located on the extension axis of the narrow hole and is a cylindrical path with a diameter equal to or slightly larger than that of the narrow hole (6) and the path is designed to have a low axial friction coefficient. For example, if the narrow hole diameter is 3 mm, multiple slits parallel to the axis can be made on the downstream side of the passage to achieve an inscribed diameter of 3 to 5 mm, or multiple piano wires with approximately 1 to 2 mm ϕ x 100 mm can be arranged in a cylindrical shape. The piano wires are preferably matte-plated to reduce friction, and gaps of approximately 0.1 to 0.5 mm are provided between them to allow ventilation.

[0027] The fiber ejected from the narrow hole (6) is fiber-opened and dispersed immediately after ejection and comes into contact with a wall defining the narrow passage to accumulate in the form of a rod due to friction with said wall (i.e., being buckled crimped). However, due to the pressure of an ejected gas, the rod is continuously discharged from the narrow passage while the shape of the resultant buckled crimp fiber rod is maintained. During buckled crimping, fixation of the microstructure of the fiber has not yet been finished, and the temperature of the fiber is high, so the fiber has more plasticity than expected and can be firmly fixed in shape. The buckled crimp fiber rod retains the inscribed shape of the narrow passage, but takes a caterpillar-like shape with numerous fluffs around the above-described slits. The numerous fluff-like fiber is generated by gas being ejected and evacuated. Meanwhile, the ejected gas is continuously discharged from a gap in said narrow passage in a direction perpendicular to the axis of the narrow passage. Furthermore, by providing a pass having a diameter that is 1.5 to 3 times as large as that of said narrow hole between said narrow hole and said narrow passage, acceleration force applied to the bundle of extruded fibers can be reduced and the separation of the fiber bundle into filaments can be promoted and a buckled crimp process by contact resistance with a wall defining said narrow passage wall can be facilitated. In this case, said narrow passage should have a diameter equal to or slightly larger than that of said pass. The narrow passage diameter is the dominant factor that determines the period of crimp, so said pass diameter is also important in this sense.

[0028] The force that continuously pushes out said buckled crimp fiber rod is the pressure of an ejected air. When said fiber rod is formed, the pressure in the compressed air chamber (3) rises by about 10 to 50 kPaG compared to that before the formation (hereinafter referred to as back pressure), so it can be seen that this functions as discharging force for the buckled crimp fiber rod. As the gap between the compressed air ejection end of the narrow hole and the top end of the buckled crimp fiber rod narrows, the back pressure, or the discharging force, increases. Meanwhile, as the gap widens, the back pressure, or the discharging force decreases. Therefore, a stable balance is reached when the gap has an appropriate value within a few millimeters.

[0029] On the one hand, if the discharging speed of the buckled crimp fiber rod is artificially increased using rollers, etc., the gap will become larger and the back pressure will decrease. On the other hand, if the discharging speed is decreased, the gap will become smaller and the back pressure will increase. For example, the back pressure can be controlled by gripping the fluffs of the buckled crimp fiber rod which have been ejected outside the narrow passage, with rollers placed on the outer periphery of said narrow passage and, at the same time, feeding the rod with the rollers. Controlling the back pressure contributes to stabilize operations. The material(s) of the feed rollers such as rubber or metal and the surface shape of the rollers such as mirror finish, matte finish, or streaky irregularities can be selected depending on the required friction coefficient of the rollers. In addition, an oil agent can be applied to the buckled crimp fiber rod through said feed rollers.

[0030] Said buckled crimp fiber rod is continuously pushed into the compressing chamber. Said compressing chamber is composed of a reverse funnel-shaped section (10), a hollow cylindrical section (16) and, for example, a piston (13) located on the opposite side of the reverse funnel-shaped section (10) and inscribed within the hollow cylindrical section. While inscribed in the reverse funnel-shaped section (10), the fiber rod meanders and spreads radially and throughout the hollow cylindrical section (16) and is laminated and compressed therein to form a compressed fiber mass. By maintaining an appropriate angle of the funnel (e.g., 20 to 120 degrees) and smoothing its connecting part between the narrow passage and the hollow cylindrical section, reversal of the lamination order of the buckled crimp fiber rod can be prevented. The angle is preferably 25 to 90 degrees, and more preferably 30 to 60 degrees.

[0031] The piston (13) slowly retreats axially in accordance with the growth of the compressed fiber mass, enabling the compressed fiber mass to be continuously produced. To increase the density of the fiber mass, it is necessary to maintain the temperature of the fiber present in the compressing chamber at a temperature not lower than the secondary transition point of the fiber and to maintain the compressive force of the piston as high as possible. For example, if the back pressure is 20 kPaG and the cross-sectional area of the compressed fiber mass is 100 cm 2< , the compressive force can be increased to nearly 20 kg / cm 2< by back pressure.

[0032] Furthermore, by applying vibrations ranging from low frequencies to ultrasonic frequencies to the compressed fiber mass in the axial direction thereof through the piston (13), it is possible to apply a significantly higher repetitive impact load thereto without affecting the feed of the buckled crimp fiber rod at the entrance of the compressing chamber. In other words, if large voids remain in the compressed fiber mass, and if the temperature of the mass is not lower than its secondary transition point, above which the compressed fiber mass will be highly plastic, vibrations rapidly decay within it and rarely reach the entrance of the compressing chamber. In other words, said vibrations significantly increase the apparent density of the compressed fiber mass without hindering the axial growth of the compressed fiber mass, and also makes the compressed fiber mass into a cake-like shape. In other words, an acceleration rate proportional to the square of the frequency is transmitted from the piston to the mass as vibration stress, making the compressed fiber mass into a more compressed cake-like form. For example, it is not particularly difficult to apply instantaneous compressive force of 100 kg / cm 2< or more to the mass through vibration compression. Furthermore, by adding high-frequency vibrations to the mass, the lubrication state at the interface between the wall of the compressing chamber and the compressed fiber mass is improved, resulting in a reduction in friction and enabling smooth movement of the fiber cake.

[0033] When the discharging speed of a buckled crimp fiber rod is artificially controlled using rollers (14) or the like, it is also possible to adjust back pressure by the feed speed of the rollers (14), and the density of the cake by the retraction speed of a piston (13). If the retraction speed of the piston (13) is too low, it becomes difficult to smoothly feed a buckled crimp fiber rod using the rollers (14). However, it is experimentally easy to adjust the retraction speed of the piston (13) so that the cake density can be made as high as possible within a range where the difficulty does not occur.

[0034] Meanwhile, it is also possible to control the growth rate of the cake by adjusting the cross-sectional area or shape of the downstream side of the compressing chamber to provide a moderate discharge resistance without using the piston (13). In this case, there is no need to move the piston to attach or detach a package, so the cake can be made endless and can be cut to any length. The discharge resistance can be adjusted by installing a resistance member in the discharge section of the compressing chamber or by changing the shape of the compressing chamber. Said shape can also be adjusted externally if the compressing chamber is made flexible. However, if the vibration compression of the piston (13) is not used, it is more difficult to increase the density of the cake.

[0035] However, if the friction between the compressed fiber mass and the compressing chamber is excessive and the feeding of the mass is not smooth, it is effective to give the hollow cylindrical section (16) of the compressing chamber slight expansion. The degree of expansion can be easily determined experimentally, and is usually 5 degrees or less, and preferably 3 degrees or less. If it is desirable to avoid expansion of the hollow cylindrical section (16) in order to maintain uniformity in the apparent density within the cake, the amount and lubricity of an oil agent can be adjusted to promote movement of the compressed fiber mass.

[0036] The density of fiber cake is unambiguously determined by the feed speed of the buckled crimp fiber rod and the retraction speed of the piston (13). If the retraction speed of the piston (13) is increased, the density of the fiber cake decreases. If the retraction speed is decreased, the density increases. However, if the retraction speed is excessively slow, feeding a buckled crimp fiber rod becomes difficult. Therefore, while the feed rate of the buckled crimp fiber rod and the retraction speed of the piston are checked, a fiber cake will be produced at the lowest possible retraction speed.

[0037] If the material of fiber can be maintained not lower than its secondary transition point within said compressing chamber to maintain the plasticity of a fiber body, it is possible to form a cake with a high apparent density. Therefore, it is desirable to install a heater or a jacket for temperature control in part or all of an area around the compressing chamber. For example, in the case of polyethylene terephthalate fiber, its melting point is around 260 degrees, and its secondary transition point is around 80 degrees, so it is desirable for the temperature inside the compressing chamber to be around 80 to 160 degrees. By feeding an appropriate amount of an oil agent through feed rollers or injecting it near the entrance of the compressing chamber, the humid-heat condition of fiber and the slippage between fibers are ensured, thereby increasing the apparent density of fiber cake. The humid-heat have a significant impact also on the transition point of the fiber. Of course, the oil agent also improves the releasability of the cake.

[0038] It is important not to allow an extruded fiber to cool at a temperature not greater than its secondary transition point before buckled crimp processing and compression into a cake. Conversely, if cooling is allowed during the process, the crystalline structure of fiber is fixed during the cooling. After that, even when the fiber is buckled crimp processed, the resultant yarn tends to revert to its original structure due to physical or chemical stimuli applied to the yarn during subsequent processing or use. This is because the processed yarn retains its property of returning to the structure formed after the cooling. The buckled-crimped compressed yarn of the present invention is buckled and compressed at the plastic stage before cooling, and does not exhibit the aforementioned structural return, making it distinct from traditional buckled-crimped processed yarn.

[0039] In addition, in the present invention, an innumerable number of indentations may be generated on the surface of fiber in association with compression formation into a cake. This is also because the fiber is compressed and formed into a cake in a highly plastic state. The indentations are not conspicuous in the case of a single fiber, but have an effect of reducing the gloss of fiber which is like that of an inorganic substance in the case of a filament fabric, for example.

[0040] It is desirable that the inner surface of said compressing chamber be a low-friction surface at least in its axial direction. Examples of such a surface include mirror surfaces and matte-finished surfaces. Furthermore, in order to promote the feeding of a cake, it is possible for at least a part of the hollow cylindrical section (16) to have a gently flared structure.

[0041] It is desirable that the said compressing chamber have a structure in which at least two detachable hollow cylindrical containers are connected in series. When the downstream side cylinder is filled with a cake, it can be separated as a fiber package and replaced with an empty cylinder.

[0042] The cross section of the hollow cylindrical compressing chamber may be approximately circular or approximately polygonal. A circular shape is the simplest. However, as a package, a container having a polygonal cross section such as triangle, quadrangle, or hexagon has the advantage of being able to be packed in boxes without gaps. Of course, the reverse funnel-shaped section (10) provided at the upstream side of the chamber is designed to be smoothly connected to the hollow cylindrical section (i.e., fiber does not get caught) regardless of the shape of the hollow cylindrical section (16). Depending on compression conditions, staining spots of buckled crimped yarn may appear in the corners of an approximately polygonal shape. However, if this is intentionally utilized, it is possible to give yarn an irregular shape and non-periodic irregularity without uneven fineness. In spinning technology using a winder, it is extremely difficult to achieve high productivity with such irregularities. Of course, such irregularities are small in a hexagonal shape and large in a triangular shape. It is unnecessary that the entire compressing chamber have such an approximately polygonal shape. Just a part of the chamber from which a package is detachable can have such a shape, or other modifications are possible. In addition, various shapes, such as oval, can also be used. It is sufficient that the cylindrical compressing chamber has a structure that does not impede the smooth feeding of a cake.

[0043] In a preferred aspect of the present invention, a high-frequency impact is applied to a crimped-compressed fiber mass by the piston (13) from the downstream side of the package toward the upstream side. This impact is of the same nature as an impact commonly used in impact tools, for example. The impact is absorbed by the plasticity of a cake (typically with a length of 200 mm or more) and by friction between the cake and the compressing chamber wall, and furthermore, with the impact applied, said piston (13) moves slowly toward the downstream side by the amount of cake growth, thus not inhibiting the cake growth. For example, continuously applying an impact of approximately 1 kg / cm 2< , 1 mm amplitude, and 10 times per second to a cake still in a highly plastic state can provide the cake with an apparent density of about 0.3 to 0.6. This value corresponds to a package weight of approximately 700 to 1400 grams when converted to a package having a diameter of 100mm and a length of 300mm. The value is sufficiently practical. On the contrary, it can be said as an exceptionally compact size for a package of buckled crimp processed yarn.

[0044] The cross-sectional area of the hollow cylindrical section (16) is determined based on the package size required during use. Small packages can be easily produced because the switching mechanism is simple. For example, a cake with a diameter of 5 cm, a length of 10 cm, and an apparent density of 0.4 g / cm 3< would have a package weight of 78.5 g. This corresponds to approximately 7 km in the case of 100D filament yarn. Folding the package in half yields a length of 3.5 km. Such end-use requirements are estimated to be not a few. Meanwhile, increasing the diameter of a cake to 10 cm or more as needed is not difficult.

[0045] The fiber obtained in the present invention exhibits pronounced characteristics of high-speed spinning. For example, in the case of polyester fiber, the degree of crystallinity is high as a whole, but the fiber is characterized by a low orientation in its amorphous region and a high orientation in its crystalline region. The strength of the polyester fiber is 3~4 g / d and the elongation is about 30~50% and the strength is insufficient for some industrial applications which require high strength, but the strength is sufficient for clothing and wadding fibers. A low amorphous orientation enhances dyeability of a fiber, and a high crystalline orientation affects the morphological stability of the fiber. Meanwhile, it is easy for fiber produced by a traditional manufacturing method, which has a low spinning speed and requires additional drawing, to achieve a high strength and a high initial elastic modulus. However, when the fiber is relaxed in a subsequent process, an unfavorable primary yield point occurs at about 1 g / d of the S-S curve of the fiber, which often causes problems in dimensional stability.

[0046] In the method of the present invention, since solidification of an extruded fiber and a buckled crimp processing are performed almost simultaneously, it is presumed that the buckled crimp processing is performed in the middle of fixing the structure of the fiber. It can be said that this is ideal to improve the fastness of crimp. In addition, the fact that indentation formation on the fiber surface is remarkable at the stage of compression formation into a cake is thought to be closely related to the fact that the fiber structure at the time of indentation formation is in the middle of fixing the fiber structure. The indentation on the fiber surface gives a subtle matte effect to a final product. As described above, the crimped compressed yarn of the present invention is crimped at a high plasticity stage before cooling, and has different quality from a conventional buckled crimped yarn which is buckled crimped after cooling once.

[0047] The above effect is basically common to both a pressurized gas chamber method and a suction gun method. However, in the suction gun method, extruded fibers are picked up in contact with the inner wall of a suction gun after solidification, whereas in the pressurized gas chamber method, extruded fibers are usually picked up in non-contact with the inner wall of a nozzle defining the narrow hole, which has the advantage in which buckled crimp processing can be performed with a lower degree of solidification. This means that a higher temperature can be maintained during a fiber processing cycle and that a higher crimp fastness can be achieved.[Examples]

[0048] Spinning material:Polyethylene terephthalate, IV 0.68Spinneret temperature:300°CSpinneret (1):0.25φ, 48HDischarge amount:120G / min

[0049] Size of hollow cylindrical section of pressurized air chamber: 150φx1.5m, placing 150φx100mm porous metal at the bottom end of hollow cylindrical section (16) Angle of funnel-shaped part (10) of pressurized air chamber: 60 degrees Pressurized air:300kPaG, 30°CNarrow hole (6):Connecting 3φx300mm path and 7φx70mm pathNarrow passage:Twelve 1φx60mm chrome-plated piano wires with a matte-finished surface are mounted coaxially with the narrow hole (6) on the downstream side to form an inscribed circle with a diameter of 8mm.

[0050] Reverse funnel-shaped section (10): Angle of 60 degrees, and the upper end of a hollow cylindrical section having a diameter of 11mm, which circumscribes the lower 5mm of the piano wire forming the narrow passage, is connected to the reverse funnel shape of the section (10) via 30R curved surface. The lower end of its inner surface is connected to the hollow cylindrical section (16) of a compression vessel via a 30R curved surface. At positions 20mm away from its upstream end and opposing each other, there are two 0.5φ oil agent supply holes.

[0051] Hollow cylindrical section of compression vessel: Inner diameter of 100φ x 400mm. The section can be attached and detached at a distance of 200mm from its upstream side. Each of its connection surfaces at the upstream and downstream ends of the section has a downward-facing 60-degree funnel-shaped surface to prevent fiber snagging. Impact piston:Column with a diameter of 99.5 mm; its compression vessel side has a flat surface perpendicular to its axis. Impact intensity, stroke, frequency: 80 kg, 2 mm, 10 c / sec Temperature inside compression vessel: 110°C

[0052] The pick-up speed reaches approximately 6000m. Once a compression container on the downstream side was filled with a 150 mm cake, the compression container was replaced with another container. Thus, continuous operation was possible. It was possible to continuously release buckled crimp yarn from a fiber cake.[Brief Description of the Drawings]

[0053] [Figure 1] Figure 1 shows an example of equipment and conditions for spinning, drawing, buckled crimping, and compression. [Figure 2] Figure 2 shows the state where a picked-up yarn becomes a buckled crimp fiber rod, which is sent to a compressing chamber. [Figure 3] Figure 3 shows the state where the feeding speed of the buckled crimp fiber rod is adjusted using rollers. [Figure 4] Figure 4 shows the state where the feeding speed of the buckled crimp fiber rod is adjusted using rollers. [Figure 5] Figure 5 shows the state where the downstream side portion of a hollow cylindrical container which downstream side portion is connected to another portion in series is separated as a package. [Figure 6] Figure 6 shows the state where crimped yarn is being released from a cake through a guide. [Industrial Applicability]

[0054] The method of the present invention enables inexpensive and safe production of an releasable buckled crimp yarn cake directly from a spinning raw material. Since the crimped yarn of the present invention is formed into a cake in a buckled state, the resultant released yarn exhibits excellent bulkiness and crimp fastness, making it suitable for manufacturing, for example, bulky sheets.

[0055] Since the cake of the present invention can be divided axially, there is no need to rewind it in dividing it into smaller pieces, which means that extremely small packages can be easily produced. The packaging apparatus of the present invention is simple, making it suitable for small-lot, high-mix production.

[0056] The fiber obtained in the present invention does not undergo a drawing process using rollers, so it does not have high strength but it does not revert to its original state at the time that it is relaxed and has excellent dimensional stability. Although flat yarn cannot be obtained by the method of the present invention, the versatility of the resultant fiber is not impaired due to its inherent crimping, as is the case with wool and cotton yarns.[Explanation of Symbols]

[0057] 1 Spinneret 2 Extruded fiber 3 Pressurized gas chamber 4 Pressurized hollow cylindrical chamber 5 Pressurized gas distribution chamber 6, 6' Narrow hole 7, 7', 7", 7‴ Crimping section 8, 8', 8", 8‴ Buckled crimp fiber rod 9, 9' Oil agent distribution chamber 10, 10' Reverse funnel-shaped section of compressing chamber 11, 11' Heating medium chamber 12, 12', 12", 12‴ Crimped-compressed fiber mass 13 Piston 14, 14' Feed roller 15 Hollow cylindrical section 16 Connecting part 17, 17' Detachable hollow cylindrical section 18 Released yarn 19 Guide

Claims

1. A manufacturing method of a releasable buckled crimp yarn cake characterized by extruding a fiber forming fluid from a spinneret into a fiber, ejecting the fiber together with a pressurized gas through a narrow hole positioned opposite to the spinneret, making the fiber into a rod of fiber having a buckled crimp in a crimping zone provided at the end of said narrow hole, sending and accumulating the rod of fiber into a compressing chamber comprising a reverse funnel-like section and a hollow cylindrical section, and making the resultant accumulated rod of fiber into a cake, with the rod of fiber compressed in the compressing chamber.

2. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein said fiber forming fluid is extruded from the spinneret into a pressurized gas chamber to form a fiber in the pressurized gas chamber.

3. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein said fiber forming fluid is extruded from the spinneret into the air to make a fiber; and the fiber is ejected together with a pressurized gas by a suction gun from the narrow hole positioned opposite to the spinneret.

4. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein, as said compressing method, the accumulated rod of fiber is compressed with vibration from the downstream side of said compressing chamber.

5. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein a means of extruding said fiber forming fluid from the spinneret into the pressurized gas chamber is melt spinning.

6. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein said rod of fiber is compressed in the compressing chamber at a temperature equal to or higher than its secondary transition point.

7. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein a feed roller is used at the time that said fiber rod is fed into said compressing chamber.

8. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 3, characterized in that said fiber is polyester-based, polypropylene-based, polyamide-based, polyethylene-based or a combination thereof.

9. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein the cross section of said hollow cylindrical section is approximately circular.

10. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein the cross section of at least portion of said hollow cylindrical section which portion is positioned on its downstream side is approximately polygonal.

11. The manufacturing method of a releasable buckled crimp yarn cake according to Claim 1, wherein said hollow cylindrical section has a detachable connecting part in series.

12. A manufacturing method of a releasable buckled crimp yarn cake characterized by ejecting a fiber together with a pressurized gas, making the fiber into a rod of fiber having a buckled crimp in a crimping zone provided at the end of said narrow hole, sending and accumulating the rod of fiber into a compressing chamber comprising a reverse funnel-like section and a hollow cylindrical section and make the resultant accumulated rod of fiber into a cake, with the rod of fiber compressed in said compressing chamber.

13. A manufacturing apparatus of a releasable buckled crimp yarn cake characterized in that the apparatus has a member which ejects a fiber from a narrow hole together with a high-speed fluid, a buckled crimping zone provided at the front end of said narrow hole, a compressing chamber comprising a reverse funnel-like section whose upper end circumscribes the front end of said buckled crimping zone and a cylindrical section.

14. The manufacturing apparatus of a releasable buckled crimp yarn cake according to Claim 13, wherein a compressing member movable in an axial direction is provided in the downstream side of said compressive chamber.

15. The manufacturing apparatus of a releasable buckled crimp yarn cake according to Claim 13, wherein said compressing member is a vibrational compressing member.

16. Manufacturing apparatus of a releasable buckled crimp yarn cake according to Claim 13, wherein said member which ejects a fiber from a narrow hole together with a high-speed fluid comprises a spinneret for extruding a fiber forming fluid into a pressurized gas chamber, the pressurized gas chamber and a narrow hole positioned the opposite side of the spinneret.

17. The manufacturing apparatus of a releasable buckled crimp yarn cake according to Claim 13, wherein said member which ejects a fiber from a narrow hole together with a high-speed fluid is a suction gun.

18. The manufacturing apparatus of a releasable buckled crimp yarn cake according to Claim 13, wherein said vibrational compressing member is a piston that is inscribed within said compressing chamber and that is capable of gradually moving toward the downstream side of the manufacturing apparatus.

19. The manufacturing apparatus of a releasable buckled crimp yarn cake according to Claim 13, wherein said hollow cylindrical section is provided with a detachable connecting part in series.

20. A releasable buckled crimp yarn cake formed by meandering, laminating and compressing a fiber rod of buckled crimp yarn.

21. The releasable buckled crimp yarn cake according to Claim 20, wherein the buckled crimp yarn is polyester-based, polypropylene-based, polyamide-based, polyethylene-based or a combination thereof.

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