JP5022249B2 - Spin block for composite fiber - Google Patents

Description

  The present invention relates to a melt spinning apparatus for composite fibers (hereinafter referred to as a spin block) used for melt spinning composite fibers composed of two or more different thermoplastic polymers.

  Two or more types of thermoplastic polymers having different components are individually extruded from the melt extruder, and these thermoplastic polymers are combined together in the spinneret pack to form side-by-side type composite fibers, seascore type composite fibers, Spinning as a composite fiber such as a sea-island type composite fiber is generally performed. In such a composite fiber melt spinning process, in order to obtain high-quality yarn, it is also necessary to optimize the flow path design for joining the component polymers inside the spinneret pack. In addition, since polymers having different melting points are used, controlling the difference in viscosity inside the spinneret pack and the difference in spinning speed at the time of discharge is also an important factor in obtaining high-quality yarn.

  From this point of view, in melt spinning of composite fibers, it is necessary to control the physical properties of the polymer in accordance with the characteristics of each polymer in order to perform stable spinning. For example, there is a difference in melting point from a high melting point polymer. When using a large low-melting-point polymer, copolymer-based polymer, or a polymer containing a large amount of additives, the spinning technology that is generally used under the operating conditions of composite fibers is used. In many cases, stable yarn production is difficult.

  Moreover, the existing melt spinning equipment for composite fibers is disclosed, for example, in Patent Document 1 (Japanese Utility Model Publication No. 62-118178) or Patent Document 2 (Japanese Utility Model Publication No. 2-26943). A structure in which a polymer conduit on the low melting side is incorporated as a conduit block into a spin block heated to a high temperature is adopted. The low melting point polymer discharged from the melt extruder is distributed to the low melting point polymer conduit.

  The advantage of attaching the conduit block to the spin block in this way is that the low-melting polymer conduit block is attached to the spin block dedicated to the single species polymer that melt-spins only the existing single species polymer. There is no need to make major modifications to the spin block. In addition, since the spin block dedicated to a single polymer can be easily remodeled into a spin block for a composite fiber, there is an advantage that capital investment can be suppressed.

  However, a major drawback of the spin block using such a stick-type conduit block is that the low melting point polymer block is attached to the wall of the spin block set at a high temperature and then distributed transport is performed. That is, since the set temperature of the spin block must transport the high-melting polymer, it has a fate that must be heated to the melting point of the high-melting polymer.

  Therefore, the low melting point polymer is inevitably transported in the spin block heated to the melting point of the high melting point polymer or higher. For this reason, the temperature of the conduit block of the low melting point polymer, that is, the polymer temperature on the low melting point side becomes the same as the spin block temperature set at a high temperature. In other words, it is impossible to control the temperature of the low melting point polymer conduit block independently, and the polymer discharged from the low melting point polymer melt extruder is exposed to a high temperature state immediately after being transported to the spin block. It becomes. This accelerates the thermal degradation of the low-temperature polymer that is weak against heat, and is also a factor of deteriorating the spinning tone due to the thermal degradation and lowering the degree of freedom in controlling the viscosity between the two-component polymers.

  In addition, when trying to obtain a fiber product having a soft texture required in the market in recent years, a fiber having a small single yarn fineness (that is, a single yarn having a small diameter) is required. Since the flow rate is reduced, the operation condition is low. For this reason, the residence time of the polymer in the spin block becomes long, so that stable spinning cannot be realized, and there is a problem that the brand and product group of the composite fiber that can be produced are limited.

  Furthermore, in addition to the quality of the fiber obtained, the method of incorporating a low-melting-point polymer conduit block into a high-temperature spin block has a problem in the equipment structure that polymer leakage is likely to occur due to the difference in coefficient of thermal expansion of the piping. is there. For this reason, sufficient verification and consideration at the design stage is necessary, which leads to an increase in the installation design and verification period. In particular, the design of a large-sized multi-fiber composite fiber spin block tends to be extremely difficult, and is one of the factors that hinder the realization of a large-sized composite fiber spin block.

  In addition, when a polymer having a low melting point that is easily deteriorated is used, there is a secondary problem that the deteriorated polymer is generated in the polymer flow path or the conduit and the flow path or the piping is easily blocked. It is necessary to remove all the polymer conduits, and further remove the spin block from the production site and incinerate it to take out the deteriorated polymer. However, once fiber production is stopped, the opportunity loss is enormous and the damage to the business will be significant.

Japanese Utility Model Publication No. 62-118178 (Microfilm of Japanese Utility Model Application No. 61-3066) Japanese Utility Model Publication No. 2-26943

  In view of the problems of the prior art described above, the problem to be solved by the present invention is “the melting temperature of the low-melting polymer possessed by the spin block for the composite fiber using the existing adhesive-type conduit block is low. Problems caused by the melting temperature of the high melting point polymer being the same in the spin block, i.e., the low temperature melting of the low melting point polymer, especially at night, deterioration of the residence time due to low flow spinning of composite fibers with small single yarn fineness It is to provide a spin block for a composite fiber that can solve the thermal degradation due to the increase and various problems caused by this.

Here, as an invention for solving the above-mentioned problem, a composite formed by combining two types of thermoplastic polymers having different melting points in a spinneret pack to form a composite polymer flow according to claim 1 is formed. In a spin block in which a polymer stream is spun from a spinneret and a composite fiber is melt-spun,
The spin block is
(1) Separated into a high temperature spin block portion and a low temperature spin block portion,
(2) A low-melting polymer conduit and a high-melting polymer conduit for transporting the molten high-melting polymer and low-melting polymer are connected to the high-temperature spin block unit and the low-temperature spin block unit, respectively. ,
(3) The low-temperature spin block unit and the low-temperature spin block unit receive the low-melting point polymer and the high-melting point polymer supplied independently from the respective conduits, respectively, and weigh them into the spinneret pack. A high-temperature gear pump and a low-temperature gear pump that are continuously supplied while being provided,
(4) Further, the high-temperature spin block unit and the low-temperature spin block unit respectively include a high-temperature heating unit and a low-temperature heating unit that individually and independently heat each predetermined temperature,
(5) The low-melting polymer is supplied to the high-temperature spin block unit via the low-temperature spin block unit and merged with the high-melting polymer directly supplied continuously to the high-temperature spin block unit. There is provided a spin block for composite fibers, which is a facility for forming a composite polymer flow in the spinneret pack and spinning as a composite fiber.

  In this case, the present invention is the “spin block for composite fiber according to claim 1, wherein a pipe connecting the high-temperature spin block unit and the low-temperature spin block unit is configured to relieve strain due to thermal expansion”. It is preferable.

  Further, the present invention is “a means for heating the high temperature heating means and the low temperature heating means by a heat medium enclosed in a pressure chamber provided in the high temperature spin block section and the low temperature spin block section, respectively. The composite fiber spin block according to claim 1 or 2 is preferably used.

  Further, the present invention provides: “Each of the low-melting polymer and the high-melting polymer flow paths and pipes incorporated outside the pressure chamber in which the heating mediums of the high-temperature heating means and the low-temperature heating means are enclosed, respectively. The composite fiber spin block according to any one of claims 1 to 3, wherein the block is detachably attached.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Here, FIG. 1 is a schematic configuration diagram showing an embodiment of a composite fiber spin block according to the present invention. FIG. 2 is a schematic configuration diagram showing an embodiment of a conventional composite fiber spin block. 1 and 2, the same reference numerals are used for members that perform substantially the same function.

  In FIG. 1 and FIG. 2, reference numerals used in common will be described. Reference numeral 1 is a melt extruder for melt-extruding a high-melting polymer used for a composite fiber, and reference numeral 2 is a melting of a low-melting polymer. Each extruder is shown. Reference numerals 3 and 4 denote a high-melting polymer conduit and a low-melting polymer conduit, respectively. Reference numerals 8 and 9 denote a high-temperature gear pump and a low-temperature gear pump, respectively. Further, reference numeral 10 indicates a spinneret pack, and reference numeral 11 indicates a spinneret mounted on the spinneret pack 10.

  Next, reference numeral 5 shown in FIG. 2 indicates a conduit block of a low-melting polymer, and reference numerals 6 and 7 shown in FIG. 1 indicate a high-temperature spin block and a low-temperature spin block, respectively. Reference numeral 13 denotes a high-temperature heat medium heating means and a low-temperature heat medium heating means, respectively. At this time, the high temperature spin block unit 6 and the low temperature spin block unit 7 are thermally separated from each other, and each of the spin block units 6 and 7 includes the high temperature heat medium heating means 12 and the low temperature heat medium. The temperature can be individually and independently controlled by the heating means 13.

  As the heating means for heating the spin block portions 6 and 7, as described above, a heating medium such as Dowtherm (trade name) is enclosed in the pressure chambers provided in the spin block portions 6 and 7, respectively, and heating is performed. The method of heating the spin block portions 6 and 7 with the heated medium is preferable from the viewpoint of uniform heating. However, the present invention is not limited to such a heating medium heating means, and a heating means using a known electric heater can also be employed.

Hereinafter, the spin block for composite fibers according to the present invention will be described with reference to FIG. 1 and, if necessary, in contrast with the conventional spin block for composite fibers illustrated in FIG.
In the embodiment illustrated in FIG. 1, on the other hand, the high melting point polymer extruded from the high melting point polymer melt extruder 1 is introduced into the high temperature spin block unit 6 through the high melting point polymer conduit 3. On the other hand, the low melting point polymer extruded from the low melting point polymer melt extruder 2 is guided to the low temperature spin block unit 7 through the low melting point polymer conduit 4.

  Therefore, the high-melting point polymer and the low-melting point polymer are separately supplied to the respective spin block units 6 and 7 through independent paths without being interfered with each other. For this reason, the heating temperature of each polymer can be controlled independently without interfering with each other. That is, the temperature can be controlled to be optimized for each polymer. Moreover, in the present invention, the spin block portions 6 and 7 are also provided separately for high temperature and low temperature, respectively. Therefore, the high-temperature spin block unit 6 and the low-temperature spin block unit 7 are independently heated by the high-temperature heat medium heating unit 12 and the low-temperature heat medium heating unit 13 without interfering with each other at any temperature. It has a structure that can.

  Further, the high temperature gear pump 8 and the low temperature gear pump 9 for continuously metering the high melting point polymer and the low melting point polymer respectively into the spinneret pack 10 are also separated into the high temperature spin block and the low temperature spin block unit 7, respectively. Is provided. Therefore, also from this point, the high temperature gear pump 8 optimized for high temperature can be used for metering high melting point polymer, and low temperature optimized for low temperature can be used for metering low melting polymer. There is an advantage that the gear pump 9 can be used. In particular, when the melt viscosity of the low melting point polymer is low, it is desirable to use the low temperature gear pump 9 optimized for metering the low melt viscosity polymer in order to further improve the metering accuracy.

  On the other hand, an embodiment of a conventional spin block is shown in FIG. 2, and the conventional spin block has a high melting point polymer spin block portion 6 and a low melting point polymer spin block portion 7 as in the present invention. These are not separated and are integrated. Moreover, as described above, in order to transport the high melting point polymer in a fluidized state and transport it in the flow path or the waste pipe, the integrated spin block 6 having a melting temperature at which the high melting point polymer does not solidify must be used. That is, it is necessary to make an integrated high-temperature spin block 6.

  Therefore, as a matter of course, the temperature of the gear pumps 8 and 9 incorporated in the integrated high-temperature spin block 6 cannot be controlled independently. Therefore, since the low melting point polymer is heated more than necessary, the melt viscosity is further lowered, and the low melting point polymer is forced to be used in a low melt viscosity region where the metering accuracy is lowered. In addition, since the low melting point polymer that is easily thermally deteriorated is heated more than necessary, there is a problem that the heat deterioration is further promoted.

  That is, in the conventional composite fiber spin block 6 illustrated in FIG. 2, the low melting point polymer conduit block 5 is incorporated into the integrated spin block 6 heated to a high temperature. Therefore, it is difficult to avoid the tendency that the temperature of the same is the same as the temperature of the high-temperature spin block 6. This is because the temperature cannot be controlled independently after the polymer temperature on the low melting point side is led to the high-temperature spin block 6. Therefore, when the spin block size is increased or when melt spinning is performed at a low flow rate, the low melting point polymer stays in the high temperature side spin block 6 for a long time. For this reason, remarkable heat deterioration is induced and stable spinning cannot be performed.

  However, there are cases where the melting temperature of the low-melting polymer cannot be made the same as the melting temperature of the high-melting polymer due to thermal deterioration. In such a case, the conduit block 5 through which the low melting point polymer flows can be thermally separated by interposing a heat insulating material or the like. However, even in such a case, the conduit block 5 needs to have a structure embedded in the width direction of the integrated spin block 6, so that expansion in the width direction occurs due to thermal expansion, and polymer leakage occurs from the joint of the conduit block 5. The structure is easy to generate. Moreover, the temperature of the low melting point polymer cannot be optimally controlled by such a method using a heat insulating material.

  Further, the polymer flow path provided in the integrated spin block 6 is generally embedded in the spin block 6 as a polymer pipe in general. For this reason, when the polymer having a low melting point, which is particularly concerned about thermal degradation, deteriorates as concerned, it causes a situation where the pipe is blocked. However, when the pipe embedded in this way is blocked even once, it is often difficult to eliminate clogging by chemical cleaning. For this reason, after disassembling the spin block 6, it is necessary to incinerate the spin block 6 and to remove polymer clogging in the pipe by this incineration process, resulting in a great opportunity loss in production.

  As described above, in the conventional spin block 6 illustrated in FIG. 2, the spin block is integrated, whereas in the spin block units 6 and 7 according to the present invention illustrated in FIG. Separately for the melting point polymer and for the low melting point polymer. Therefore, it is possible to transport the polymer through the flow paths in the spin block portions 6 and 7 that are optimally set to temperatures near the respective melting points, and in particular, it is possible to suppress thermal degradation of the polymer on the low melting point side. .

  However, considering that the high melting point polymer and the low melting point polymer are joined to form a composite polymer stream and spinning from the spinneret pack 10, the spinneret pack 10 must be formed according to the melting temperature of the high melting point polymer. It must be provided in the high temperature spin block section 6. For these reasons, in order to melt-spin the composite fiber satisfactorily, it is important to design a flow path in which the high melting point polymer and the low melting point polymer are joined in the spinneret pack 10. Therefore, the low melting point polymer entrance from the low temperature spin block unit 7 and entering the high temperature spin block unit 6 is provided as close as possible to the spinneret pack 10 provided in the high temperature spin block unit 6. Further, the arrangement of the flow path or piping of the low melting point polymer in the high temperature spin block unit 6 is designed so that the time during which the low melting point polymer stays in the high temperature spin block unit 6 can be shortened as much as possible.

  By doing so, it is possible to shorten the time in which the polymers are merged as much as possible, and a new low-temperature spin block unit 6 that is individually and independently temperature-controlled according to the temperature of the low melting point polymer is newly provided. As a result, a spin block for composite fibers capable of transporting the low-melting-point polymer while suppressing the occurrence of thermal degradation as much as possible immediately before the entrance to the spinneret pack 10 is realized.

  As described above, in the spin block units 6 and 7 according to the present invention, the low melting point polymer introduced from the low temperature spin block unit 7 to the high temperature spin block unit 6 is a high temperature spin block set to a high temperature. The time required for exposure to high temperature in the part 6 is reduced as much as possible. In other words, the polymer conduits 3 and 4 and the gear pumps 8 and 9 are connected from the melt extruders 1 and 2 so that the temperature of each polymer flowing therethrough does not interfere with each other, as well as the flow paths and piping of each polymer. In this way, a structure in which each of the spin block units 6 and 7 can be controlled individually is employed.

  Therefore, individual flow control as well as individual temperature control for each polymer can be easily performed. For this reason, even a composite fiber having a small single yarn fineness can be melt-spun while effectively suppressing side effects such as thermal degradation. Therefore, there is an effect that various brands of fiber products can be manufactured while maintaining stable and excellent quality by using the spin block according to the present invention.

  The spin block of the present invention is separately provided in the high temperature spin block unit 6 and the low temperature spin block unit 7 and heated to a predetermined temperature. Therefore, in each spin block part 6 or 7, the thermal expansion coefficient of the polymer pipe or the like can be made constant in each spin block part 6 and 7 as long as the same material is used. Therefore, polymer leakage due to thermal expansion in each of the spin block portions 6 and 7 can be eliminated. However, only the pipe connecting the low-temperature spin block unit 7 and the high-temperature spin block unit 6 is a problem. For such a pipe connection, an expansion joint such as a well-known telescope type or bellows type, or an expansion structure pipe is used. The effects of thermal expansion can be easily eliminated by adopting etc.

  Further, in the spin block according to the present invention, the polymer passes not only through the low-temperature side spin block unit 7 but also through the high-temperature side spin block unit 6, which is particularly susceptible to thermal deterioration and the flow path and piping are likely to be blocked. All the flow paths to be performed are individually blocked, and are configured to be detachably attached to each outer wall of the pressure chamber in which the heat medium of the heat medium heating means 12 and 13 is sealed. Therefore, even when a polymer blockage occurs in the conduit, the polymer can be removed by removing only the blocked portion without disassembling the entire spin block.

  Such a structural design is possible because the conventional spin block unit 6 eliminates complicated problems caused by mutual temperature interference and flow rate interference caused by sharing the low melting point polymer and the high melting point polymer. This is because the problem of such mutual interference can be essentially avoided in the spin block units 6 and 7 according to the present invention.

  In this way, it is possible to control the thermal degradation of the polymer by making the temperature control of the spin block on the low temperature side and the high temperature side individually, and of course, the temperature difference between the low melting point polymer and the high melting point polymer is positive. Can be set automatically. For this reason, the “degree of freedom in controlling the difference in viscosity of each polymer component”, which is an important factor in melt spinning of composite fibers, is also increased, and the section design of the composite fibers and the discharge rate control of the polymer discharged from the spinneret 11 are easy. It becomes. As a result, it is possible to prevent the bending of the polymer immediately after being discharged from the spinneret 11 and to suppress the yarn breakage due to the accumulation of foreign matter on the edge of the spinning hole, and to stably produce the composite fiber brand with high technical difficulty. Is possible.

It is the schematic which showed typically arrangement | positioning of one embodiment of the spin block concerning this invention. It is the schematic which showed typically arrangement | positioning of the embodiment example of the conventional spin block.

Explanation of symbols

1. 1. Melting extruder for high melting point polymer 2. Melt extruder for low melting polymer 3. High melting point polymer conduit 4. Low melting polymer conduit 5. Low melting polymer conduit block 6. High temperature spin block Low temperature spin block 8. 8. High-temperature gear pump Low temperature gear pump10. Spinneret pack 11. Spinneret 12. High temperature heating medium heating means 13. Heating medium heating means for low temperature

Claims (4)

In a spin block in which two types of thermoplastic polymers having different melting points are combined in a spinneret pack to form a composite polymer stream, and the formed composite polymer stream is spun from the spinneret to melt-spin the composite fiber.
The spin block is
(1) Separated into a high temperature spin block portion and a low temperature spin block portion,
(2) A low-melting polymer conduit and a high-melting polymer conduit for transporting the molten high-melting polymer and low-melting polymer are connected to the high-temperature spin block unit and the low-temperature spin block unit, respectively. ,
(3) The low-temperature spin block unit and the low-temperature spin block unit receive the low-melting point polymer and the high-melting point polymer supplied independently from the respective conduits, respectively, and weigh them into the spinneret pack. A high-temperature gear pump and a low-temperature gear pump that are continuously supplied while being provided,
(4) Further, the high-temperature spin block unit and the low-temperature spin block unit respectively include a high-temperature heating unit and a low-temperature heating unit that individually and independently heat each predetermined temperature,
(5) The low-melting polymer is supplied to the high-temperature spin block unit via the low-temperature spin block unit and merged with the high-melting polymer directly supplied continuously to the high-temperature spin block unit. A spin block for a composite fiber, which is a facility for forming a composite polymer flow in the spinneret pack and spinning as a composite fiber.   2. The composite fiber spin block according to claim 1, wherein a pipe connecting the high temperature spin block unit and the low temperature spin block unit has a structure that relieves strain due to thermal expansion.   The heating means for high temperature and the heating means for low temperature are means for heating by a heat medium sealed in a pressure chamber provided in the high temperature spin block portion and the low temperature spin block portion, respectively. 2. A spin block for composite fibers according to 2.   Each block incorporating the low-melting-point polymer and the high-melting-point polymer flow path and piping is detachably attached to the outside of each pressure chamber in which the heating medium for the high-temperature heating means and the low-temperature heating means is enclosed. The spin block for composite fibers according to any one of claims 1 to 3.

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