Spinning apparatus

Abstract

To provide a spinning apparatus having a small polymer residence area in a pack, being compact, and capable of obtaining a yarn having stable quality with high productivity.SOLUTION: A spinning apparatus has a spinneret pack for melt spinning provided with a spinneret having discharge holes bored for discharging a polymer in fibrous form, and the spinneret pack is bored with an inflow hole into which the polymer flows, and has, at a downstream side of the inflow hole, a filtration layer having a volume of 100 to 800 cm3 for filtering the polymer having flowed in, and further has, at a downstream side of the filtration layer, a plurality of polymer flow passages arranged circumferentially, wherein the inner diameter of the polymer flow passages is 2.9 to 7.1 mmφ, the number of the polymer flow passages is 12 to 40, and a wire mesh filter and an annular spinneret are provided directly under a downstream side of the polymer flow passages.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a spinning device, and more particularly to a spinning device in which the polymer residence area in the pack is small, compact, and stable-quality yarn can be obtained with high productivity.

Background Art

[0002] Heretofore, techniques for improving productivity by making the die porous have been studied. For example, in Japanese Unexamined Patent Application Publication No. 2019-7098 (Patent Document 1), a die having 3,500 or more die holes has been proposed. On the other hand, there has been a problem that the die used in the spinning equipment becomes large, resulting in a large-scale spinning equipment. In order to solve such a problem of the enlargement of the spinning equipment, Japanese Unexamined Patent Application Publication No. 2020-158904 (Patent Document 2) proposes a spinning device having high productivity and being compact.

[0003] On the other hand, in high-efficiency spinning using a multi-hole die having 1,000 or more holes, it is difficult to stabilize productivity and quality only by devising the die hole arrangement and the yarn cooling method, and it has been found that it is important to make the viscosity of the molten polymer discharged from the die uniform.

[0004] As a result, for example, Japanese Unexamined Patent Application Publication No. 2003-342827 (Patent Document 3) proposes a melt spinning die pack capable of reducing deterioration of process conditions such as yarn breakage and generation of yarn quality spots caused by abnormal residence and deterioration of the polymer. In this invention, the polymer residence amount in the pack is significantly reduced, and the average residence time is also extremely shortened, so that thermal degradation due to the thermal history received while the polymer resides in the pack can be suppressed.

[0005] On the one hand, in Patent Document 3, since the polymer flow path directly above the die is drilled in the central part inside the pack and is far from the polymer introduction part of the die, it is difficult to evenly distribute the polymer to all holes in a multi-hole die with 1000 or more holes, and there is a problem that ejection failure and thread quality failure occur. Further, since it has a structure without a filtration layer, ejection failure and thread breakage are likely to occur due to foreign matter clogging, and application to continuous production is not practical.

[0006] To solve such problems, for example, as disclosed in Japanese Patent Application Laid-Open No. 2005-194673 (Patent Document 4), there is known one provided with a distribution plate for evenly distributing the polymer to the polymer introduction holes of the die. However, when a distribution plate is provided, there is a drawback that the polymer retention amount in this part increases and the thermally deteriorated polymer is introduced into the die, resulting in thread quality spots.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention has been made based on the above background, and an object thereof is to provide a spinning device capable of obtaining a yarn with stable quality with a small polymer retention area in the pack, being compact and having high productivity.

Means for Solving the Problems

[0009] As a result of extensive investigations aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by providing a filtration layer below an inflow hole through which the polymer flows, for filtering the flowing polymer, and controlling the size of the filtration layer, and by forming a plurality of polymer flow paths which are arranged circumferentially below the filtration layer and whose inner diameters and numbers are controlled, thereby completing the present invention.

[0010] That is, according to the present invention, 1. A spinning apparatus having a melt spinning nozzle pack equipped with a spinneret having a discharge hole for discharging a polymer in a fibrous form, the nozzle pack having an inlet hole through which the polymer flows in, and a 100 to 800 cm filter for filtering the inflowing polymer on the downstream side of the inlet hole. 3 a filtration layer having a volume of 1000 mm, and further having a plurality of polymer flow paths arranged in a circumferential shape on the downstream side of the filtration layer, the inner diameter of the polymer flow paths being 2.9 to 7.1 mmφ, the number of the polymer flow paths being 12 to 40, and a wire mesh filter and an annular spinneret being provided immediately below the downstream side of the polymer flow paths. 2. The spinning apparatus according to the above item 1, wherein the distance from the lower end of the polymer flow path to the upper end of the polymer inlet of the spinneret is 0.1 to 10.0 mm. 3. The spinning apparatus according to 1 or 2 above, having a static mixing element in a polymer flow path, the static mixing element having 2 to 20 elements and a length (L) / diameter (D) ratio (L / D) per element being 0.3 to 3.0. 4. The number of discharge holes drilled in the die is 2000 to 9000, and the hole density of the discharge holes is 0.15 to 0.85 / mm 2 3. The spinning apparatus according to claim 1 or 2, 5. The spinning apparatus according to 1 or 2 above, wherein, when the distance between the center of the outermost concentric nozzle hole among the nozzle holes drilled in the spinneret and a predetermined point in the spinneret is X1, and the distance between the center of the innermost concentric nozzle hole in the spinneret and a predetermined point in the spinneret is X2, the nozzle row arrangement coefficient X2 / X1 is 0.40 to 0.85. And, 6. The spinning device according to the above item 1 or 2, which has a mechanism for sucking a medium for cooling the yarn from the outside of the discharge hole on the polymer discharge side of the spinneret. is provided.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a spinning device that has a small polymer residence area in the pack, is compact, and can obtain yarns of stable quality with high productivity.

Brief Description of the Drawings

[0012]

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Figure 10

Embodiments for Carrying Out the Invention

[0013] Hereinafter, the present invention will be described in detail.

[0014] (1) Melt spinning spinneret pack Hereinafter, embodiments of the spinneret pack for melt spinning of the spinning apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic explanatory view illustrated for explaining the pack of the present invention, showing a schematic front cross section. In this figure, reference numeral 01 indicates a melt spinning spinneret pack, and this pack 01 is composed of a pack upper plate 1, a pack lower plate 2, a spinneret holder 3, and a spinneret presser 4.

[0015] Here, various pack members incorporated in the pack lower plate 2 are at least composed of a filter layer 5, a polymer flow path 6, a wire mesh filter 7 having a seal member on the outer periphery, and a spinneret 8 in order in the introduction direction of the polymer indicated by the arrow in FIG. 1.

[0016] At this time, the volume of the filter layer 5 needs to be 10 to 800 cm 3 . Thermoplastic polymers such as polyester and polyamide, when staying in the pack for a long time in a heated state, thermally deteriorate, gelate, or carbonize, resulting in yarn breakage, quality spots, etc. Since such polymers are highly viscous substances, the flow velocity outside the flow path tends to decrease due to the wall resistance of the polymer flow path, etc., and a residence time difference occurs. Further, since the outer peripheral surface of the pack lower plate 2 is surrounded by a heat insulation heating device, a temperature difference occurs between the center part and the peripheral part of the pack, and the polymer flowing through the internal flow path outside the pack receives more heat than the polymer flowing through the internal flow path inside. In such a state, when the factors of the residence time difference and the heat history difference generated in the pack overlap, polymer deterioration is likely to occur in the flow path located on the outer peripheral side in the pack.

[0017] Therefore, when the volume of the filter layer exceeds 800 cm 3 , it is not preferable because the amount of polymer thermally deteriorated due to the residence time difference generated in the filter layer increases. The volume of the filter layer is preferably 50 to 600 cm 3 , more preferably 100 to 500 cm 3 .

[0018] Next, the polymer flow path 6 is provided with a plurality of polymer flow paths arranged circumferentially to secure a flow path for introducing the polymer filtered by the filtration layer 5 into the die. In conventional packs, those having a polymer flow path drilled in the central part of the pack as in Patent Document 3 or those provided with a distribution plate for evenly distributing the polymer to the polymer introduction holes of the die are known (for example, JP-A-2005-194673). However, in the structure of Patent Document 3, in a die having a circular tube shape and a large number of holes, it is difficult to evenly distribute the polymer to all the holes, and thread quality spots are generated. On the other hand, if a distribution plate is provided to evenly distribute the polymer to all the holes of the die, the amount of polymer retained in this part increases, and the thermally deteriorated polymer is introduced into the die and becomes thread quality spots.

[0019] By making the polymer flow path 6 a polymer flow path from the filtration layer to directly above the polymer introduction hole of the die, the polymer can be evenly distributed to all the holes of the porous die, and by providing a static mixing element 9 in the flow path, it is possible to alleviate the viscosity difference caused by the difference in thermal history and residence time in the pack.

[0020] It is preferable to provide the aforementioned polymer flow path 6 with a static mixing element 9 (static mixer). Thereby, each polymer flowing on the wall surface side and the center side of the polymer flow path can be mixed, and it is possible to homogenize the viscosity spots of the polymers that have received different thermal histories on the wall surface side and the center side. As the static mixing element 9, a known Kenics type or Sulzer type is used, and the mixing effect of the polymer improves as the number of its elements increases. On the other hand, if the number of elements is too large, the length of the static mixing element also becomes correspondingly long, and there arises a problem that the residence time of the polymer and the overall height of the pack 01 increase. The number of elements that can homogenize the viscosity difference of the polymer and maintain a compact pack size is 2 to 20, more preferably 3 to 15, and the ratio (L / D) of the length (L) to the diameter (D) per element is preferably 0.3 to 3.0, more preferably 0.5 to 2.0.

[0021] Note that the inner diameter of the polymer flow path 6 where the static mixing element 9 is provided needs to be 0.2 to 8.0 mm, preferably 1.5 to 7.5 mm, and more preferably 2.9 to 7.1 mm. If the inner diameter exceeds 8.0 mm, the polymer flow rate represented by the inner diameter of the polymer flow path 6 × the number of flow paths will be outside the pack size range, and the polymer retention amount in the flow path will increase. On the other hand, if the inner diameter is less than 0.2 mm, the polymer flow rate will be insufficient for the number of holes, and the polymer cannot be uniformly supplied to all holes. Due to the flow path resistance, the pack pressure on the upstream side will increase, and the polymer will leak from the upper part of the pack. In addition, it will be difficult to manufacture the polymer flow path, and the manufacturing cost will increase.

[0022] Also, the number of the polymer flow paths 6 needs to be 12 to 40. If the number is less than 12, the polymer distributability will decrease, and stable polymer discharge will become impossible. On the other hand, if the number exceeds 40, the polymer flow rate represented by the inner diameter of the polymer flow path 6 × the number of flow paths will be outside the pack size range, and spinning will be abnormal. The length of the polymer flow path is 10 to 150 mm, more preferably 50 to 130 mm.

[0023] Here, the distance from the lower end of the polymer flow path to the upper end of the polymer introduction part of the spinneret is preferably 0.1 to 10.0 mm. By setting it within this range, while uniformly supplying the polymer to all holes of the spinneret, the polymer retention amount directly above the spinneret can be minimized, and as a result, uniform yarn quality can be obtained. Preferably, it is 0.5 to 8.0 mm, more preferably 0.5 to 3.0 mm.

[0024] Also, a wire mesh filter 7 is provided between the lower end of the polymer flow path 6 and the upper end of the spinneret introduction part, and it is necessary to have a structure for capturing foreign matters mixed into the spinneret introduction part. Note that a seal member made of a material such as aluminum is formed on the outer peripheral edge of the wire mesh filter 7. When the lower plate 2, the spinneret holder 3, and the spinneret presser 4 are screwed and fastened to each other with their screw parts, this seal member is clamped, thereby playing a role in preventing polymer leakage to the outside of the pack 01.

[0025] (2) Nozzle The spinneret used in the present invention is provided on the downstream side of the wire mesh filter, and a plurality of discharge holes are formed in the spinneret. The number of discharge holes is 2,000 or more and 9,000 or less. If the number of discharge holes is 2,000 or more, spinning becomes easy with high productivity. The number of discharge holes is preferably 2,500 or more, more preferably 3,000 or more, and still more preferably 3,500 or more.

[0026] On the other hand, if the number of discharge holes is 9,000 or less, it becomes easy to improve the strength of the spinneret. The number of discharge holes is preferably 8,000 or less, more preferably 7,000 or less. In the present invention, while miniaturizing the spinneret and making the spinning device compact, it is possible to increase the spinning production capacity. Therefore, the present invention has realized that the hole density of the spinneret can be increased.

[0027] In the prior art, in view of the hole arrangement region and the number of holes, the hole density is about 0.1 hole / mm 2 degree. However, the hole density on the spinneret surface used in the present invention is 0.15 holes / mm 2 or more and 0.85 holes / mm 2 or less, and the hole density is increased compared to the conventionally known technology. Furthermore, the preferable range of the hole density is 0.20 holes / mm 2 or more and 0.80 holes / mm 2 or less, more preferably 0.25 holes / mm 2 or more and 0.75 holes / mm 2 or less, and still more preferably 0.30 holes / mm 2 or more and 0.70 holes / mm 2 or less.

[0028] Here, the hole density can be calculated from the area of the portion on the spinneret surface where the holes are arranged and the number of holes. Also, in order to increase the hole density, it can be achieved by increasing the number of holes without changing the die size. When not changing the die size, it is preferable in that the existing equipment can be utilized as it is.

[0029] When the hole density is less than 0.15 holes / mm 2 If it is less than this value, when using a multi-hole die, the die size becomes large, and the spinning equipment itself becomes large, making it impossible to achieve the object of the present invention. On the other hand, when the hole density on the spinneret surface exceeds 0.85 holes / mm 2 even when using a mechanism (yarn cooling device) that sends a medium (cooling air) for cooling the yarn from the center of the die to the outer peripheral direction, which is another element of the present invention described later, the cooling air does not escape uniformly, generating abnormal yarns such as thick yarns, thin yarns, and adhesion, deteriorating the quality of the raw yarn (undrawn yarn), and deteriorating the spinning condition, which is not preferable.

[0030] The diameter of the die for arranging the holes in the present invention is preferably 100 mm or more and 300 mm or less. More preferably, it is 250 mm or less, and even more preferably 200 mm or less. When it is less than 100 mm, the number of discharge holes decreases when the above-mentioned hole density is set, resulting in low productivity, which is not preferable.

[0031] In the prior art, the diameter of the die is a large size exceeding 300 mm. As described above, by increasing the hole density of the present invention, the spinneret can be made compact and the productivity can be improved.

[0032] Although the arrangement and interval of the discharge holes are not particularly limited, considering the distributability of the thermoplastic resin, it is preferable that the row intervals are equal, and it is more preferably arranged in a plurality of annular shapes with the center inside the annular die as the center point.

[0033] As an example of a preferable hole array, a radial array in which discharge holes are radially arranged on a straight line in the radial direction from the center of the die (Fig. 3), or a staggered array in which holes are arranged in a staggered pattern in adjacent annular hole arrays (Fig. 4) are also preferable arrays.

[0034] Also, in any annular hole array, an equidistant array (Fig. 5) in which the intervals between adjacent discharge holes within the annular array are all the same is also a preferable array from the viewpoint of the distributability of the thermoplastic resin. Among them, the radial array is more preferable because the discharge holes are formed in parallel radially, and when cooling air is blown from the inside to the outside under the die against the bundle of spun yarns spun from the spinning die to cool the yarn, it is easier for the cooling air to pass through.

[0035] The discharge holes form a group of annular arrays with different diameters from the center of the annular spinning die, and a group of hole aggregates arranged in an annular array with the same diameter are regarded as the same row. The discharge holes are preferably arranged in 9 rows or more and 22 rows or less. By positioning the discharge holes on the circumferences of concentric circles with different diameters of 9 rows or more, it is possible to easily increase the number of discharge holes and perform spinning with high productivity. The number of concentric circle rows is more preferably 10 rows or more, and even more preferably 12 rows or more.

[0036] On the other hand, by positioning the discharge holes on the circumferences of concentric circles with different diameters of 22 rows or less, it is possible to easily maintain the pressure-resistant deformation strength of the spinning die. And the number of concentric circle rows is more preferably 21 rows or less, and even more preferably 20 rows or less. And the number of discharge holes on the circumference of the annular spinning die is preferably the same in any two concentric circle rows. Thereby, it is possible to easily distribute the spinning solution evenly.

[0037] The number of discharge holes in each circumferential row is not particularly limited, but is preferably 200 or more and 500 or less, respectively. When the number of discharge holes in each circumferential row is 200 or more, the total number of discharge holes on the spinneret surface can be increased, and spinning can be facilitated with high productivity. More preferably, it is 240 or more, and even more preferably 300 or more. On the other hand, when the number of discharge holes 2 in each circumferential row is 500 or less, the strength of the spinneret can be easily improved. More preferably, it is 450 or less, and even more preferably 400 or less. Also, the intervals between the discharge holes in the same circumferential row are preferably equal. Thereby, it becomes easy to evenly distribute the molten resin to the discharge holes.

[0038] When the distance between the center of the discharge holes of the outermost concentric circle in the spinneret and the center point inside the spinneret is X1, and the distance between the center of the discharge holes of the innermost concentric circle in the spinneret and the center point inside the spinneret is X2 (see Fig. 7), the discharge hole arrangement coefficient X2 / X1 is preferably 0.40 or more and 0.85 or less. When the discharge hole arrangement coefficient is less than 0.40, cooling spots may occur in the innermost and outermost layers of the concentric circles, which is not preferable. On the other hand, when the discharge hole arrangement coefficient exceeds 0.85, the upper limit of the number of concentric circles becomes small, it becomes difficult to achieve the target multi-hole spinneret, and it is not preferable because productivity is difficult to increase.

[0039] When the cross-sectional area of the introduction part on the resin supply side in the spinneret is Y1 and the cross-sectional area on the resin discharge side is Y2 (see Fig. 6), the discharge hole compression coefficient Y2 / Y1 is preferably 0.010 or more and 0.080 or less.

[0040] When the discharge hole compression coefficient Y2 / Y1 is less than 0.010, the discharge hole pressure loss becomes high, and the equipment load increases, etc., so it is not preferable because productivity is difficult to increase. On the other hand, when the discharge hole compression coefficient Y2 / Y1 exceeds 0.080, a portion where resin does not flow easily occurs on the resin supply side surface of the spinneret, resulting in quality differences such as thermal degradation of the resin, making it difficult to obtain a uniform fiber bundle, so it is not preferable.

[0041] In the spinneret, when the hole length of the resin discharge part is Z2 with respect to the diameter Z1 of the resin discharge part (see Fig. 6), the ratio Z2 / Z1 of the hole length to the hole diameter of the discharge hole is preferably 1.0 or more and 5.0 or less. When Z2 / Z1 is within this range, the heat of the molten resin is likely to be transferred to the die surface, and since the atmosphere temperature at the lower part of the die is low, the die surface is cooled, making it less likely to suffer from poor discharge of the molten resin. If Z2 / Z1 is less than 1.0, it is not preferable because poor discharge occurs due to the expansion of the resin (so-called barus effect) after passing through the discharge hole. Also, when Z2 / Z1 exceeds 5.0, the discharge hole pressure loss increases, and it becomes difficult to increase productivity due to factors such as a large equipment load, so it is not preferable. More preferably, Z2 / Z1 is 1.0 or more and 4.0 or less, and even more preferably, it is 1.0 or more and 3.0 or less.

[0042] Examples of the material of the spinneret include stainless steel and cemented carbide. Examples of stainless steel include SUS316 and SUS630. Examples of cemented carbide include tungsten carbide-based cemented carbide. Tungsten carbide-based cemented carbide is an alloy obtained by sintering tungsten carbide using at least one metal selected from the group consisting of iron, cobalt, nickel, titanium, and chromium.

[0043] On the surface of the spinneret, a vapor deposition film may be formed to improve corrosion resistance and the mold release property of the resin. Examples of the material of the vapor deposition film include carbon-based compounds such as diamond-like carbon; boron-based compounds such as titanium boron nitride, chromium boron nitride, and silicon boron nitride; chromium-based compounds such as chromium nitride; and titanium-based compounds such as titanium carbonitride, titanium nitride, and titanium aluminum nitride.

[0044] Furthermore, in the discharge hole of the spinneret, it is preferably in a tapered shape in which the discharge cross-sectional area continuously expands. By making the discharge surface in a tapered shape, the swelling of the polymer due to the barus effect at the discharge part can be reduced, and as a result, the flow of the polymer can be stabilized.

[0045] Here, it is preferable that the angle θ (taper angle) of the discharge surface is 3° or more and 40° or less from point A where the cross-sectional area starts to expand. What is important in the spinneret of the present invention is to set the taper angle θ within a specific range. That is, more preferably, it is necessary to be within the range of 5° to 30°, and even more preferably within the range of 10° to 20°. When the taper angle exceeds 40°, the swelling of the polymer due to the die swell effect becomes large, and once the greatly swollen polymer is rapidly thinned by the stretching tension, the internal stress acting on the polymer at this time becomes non-uniform, which may destabilize the polymer flow. When the taper angle is less than 3°, it is preferable from the viewpoint of increasing the back pressure. However, when oligomers adhere to the discharge part over time, the polymer flow becomes non-uniform and yarn breakage is likely to occur. As a countermeasure against foreign matters on the discharge surface, it is preferable to provide the vapor deposition film on the discharge surface of the die as described above and set the taper angle within the above range.

[0046] (3) Cooling medium Next, a so-called yarn cooling air blowing device having a mechanism for sending a medium for cooling the yarn according to the present invention from the inside of the discharge hole on the discharge side of the spinneret to the outside of the discharge hole on the discharge side of the spinneret will be described in detail.

[0047] When cooling by blowing cooling air onto a yarn made of molten resin discharged downward from the die hole, a cooling device that blows from the outside of the discharge hole array on the discharge side of the spinneret toward the inside of the discharge hole array has been conventionally known. (An example is shown in FIG. 10.) In this case, the cooling air that has passed through the yarn causes complex yarn vibration due to the turbulent flow of air caused by the collision near the center of the die surface, etc., which makes the cooling of the yarn unstable. In addition, the hole density on the spinneret surface is 0.15 holes / mm 2 or more and 0.85 holes / mm 2At a high hole density as described below, it is difficult for the cooling air to penetrate, and as it approaches the center of the die, the cooling difference of the yarn becomes significant, making it difficult to obtain a raw yarn (undrawn yarn) of uniform quality. Also, as can be seen from, for example, the radial arrangement shown in FIG. 3 and the staggered arrangement shown in FIG. 4, when the discharge holes are directed from the outside to the inside of the discharge hole arrangement on the discharge side of the spinning die, the hole spacing becomes narrower as the hole row approaches the inner layer, and the tendency of adjacent yarns to adhere due to contact has a significant impact on the yarn quality.

[0048] On the other hand, as in the present invention, when the cooling medium (for example, cooling air) is directed from the inside to the outside of the discharge hole arrangement on the discharge side of the spinning die, the yarns existing on the same circumference have the merit of being less likely to adhere because they spread to the outside of the hole arrangement. That is, with the spinning device having the spinning die and the yarn cooling mechanism of the present invention, it becomes possible to improve the quality and productivity of the yarn.

[0049] Also, in order to improve the uniformity of the cooling air passing through the yarns released from a predetermined point, by sucking from the outside of the lower part of the spinning die, it is possible to obtain a higher productivity and a uniform yarn, and at the same time, it is possible to prevent the die from cooling and causing poor discharge of the thermoplastic resin. There is also an advantage that it is preferable. An example of the installation of a specific suction mechanism is shown in FIG. 10.

[0050] (4) Spinning conditions In the present invention, there is no particular limitation as long as it is a resin known to be melt-spinnable, but examples thereof include polyester resins, polyolefin resins, aliphatic polyamide resins, polyphenylene sulfide, etc. Also, it may be applied to a die using two or more kinds of resins, such as not only a single hole but also composite fibers such as core-sheath type, side-by-side type, segment pie type, and sea-island type.

[0051] As a representative of the resin preferably used in the present invention, polyester resins are specifically exemplified. Polyester of aromatic dicarboxylic acid and aliphatic diol such as polyalkylene terephthalate such as polyethylene terephthalate, polytrimethylene terephthalate, or polybutylene terephthalate (polytetramethylene terephthalate), or polyethylene naphthalate, polytrimethylene naphthalate, or polybutylene naphthalate (polytetramethylene naphthalate) can be exemplified. Alternatively, it can be a polyester obtained from an alicyclic dicarboxylic acid such as polyalkylene cyclohexanedicarboxylate and an aliphatic diol, a polyester obtained from an aromatic dicarboxylic acid and an alicyclic diol such as polycyclohexane dimethylene terephthalate, a polyester obtained from an aliphatic dicarboxylic acid and an aliphatic diol such as polyethylene succinate, polybutylene succinate, or polyethylene adipate, or a polyester obtained from a polyhydroxycarboxylic acid such as polylactic acid or polyhydroxybenzoic acid. Or as a resin that becomes a polyester-based fiber, copolymers or blends of these polyester components in any ratio are also preferably exemplified.

[0052] Depending on the purpose, as the dicarboxylic acid component constituting the polyester, isophthalic acid, phthalic acid, alkali metal salts of 5-sulfoisophthalic acid, quaternary ammonium salts of 5-sulfoisophthalic acid, quaternary phosphonium salts of 5-sulfoisophthalic acid, succinic acid, adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, α,β-(4-carboxyphenoxy)ethane, 4,4-dicarboxyphenyl, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid or 1,4-cyclohexanedicarboxylic acid or diester compounds composed of these organic groups having 1 to 10 carbon atoms may be copolymerized as one component or two or more components. Similarly, as the diol component constituting the polyester, diethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 2,2-bis(p-β-hydroxyethylphenyl)propane, polyethylene glycol, poly(1,2-propylene) glycol, poly(trimethylene) glycol or poly(tetramethylene) glycol etc. may be copolymerized as one component or two or more components. Further, it is also preferable that it is a polyester having branches by copolymerizing one component or two or more components of hydroxycarboxylic acids such as ω-hydroxyalkylcarboxylic acid, pentaerythritol, trimethylolpropane, trimellitic acid, or trimesic acid, or compounds having three or more carboxylic acid components or hydroxyl groups. It is also possible to use a mixture of polyesters having different compositions exemplified above.

[0053] Among them, as the polyester resin preferably used in the present invention, it is preferable that it is a polyalkylene terephthalate resin or a polyalkylene naphthalate resin from the viewpoint of its good physical properties and handleability.

[0054] The intrinsic viscosity of the fiber used in the present invention is preferably 0.35 to 0.80 dL / g, and particularly when the main component constituting the fiber is polyethylene terephthalate, the intrinsic viscosity is more preferably 0.40 to 0.75 dL / g, and even more preferably 0.45 to 0.70 dL / g. If the intrinsic viscosity is too low, the strength of the fiber decreases and it tends to be difficult to fiberize. On the other hand, if the intrinsic viscosity is too high, the performance of the obtained fiber tends to deteriorate, such as a decrease in stretchability, which is not preferable.

[0055] The discharge amount per hole in the present invention is preferably 0.05 g / min or more and 1.00 g / min or less, more preferably 0.08 g / min or more and 0.90 g / min or less, and even more preferably 0.10 g / min or more and 0.80 g / min or less. If it is less than 0.05 g / min, the discharge hole pressure loss becomes low and uneven discharge of the thermoplastic resin occurs, which is not preferable. Also, if it exceeds 1.00, the internal pressure on the upstream side of the discharge hole becomes too high and it is difficult to stably discharge the thermoplastic resin, which is not preferable.

[0056] The spinning speed in the present invention preferably has a take-up speed of 300 to 2000 m / min, more preferably 400 to 1900 m / min, and even more preferably 500 to 1800 m / min. If it is less than 300 m / min, the toughness of the yarn is small and it is difficult to obtain a yarn with good stretchability. If it exceeds 1800 m / min, it is difficult to obtain a sufficient draw ratio and the spinning breakage increases, which is not preferable.

[0057] Also, it is preferable to install an oiling device during the process of taking up at the above-mentioned predetermined spinning speed. The surfactant used for oiling is preferably an emulsion such as anionic or nonionic, and the application method may be any of a spray method, an oiling roller method, a metering oiling nozzle method, etc.

Examples

[0058] In order to specifically describe the configuration and effects of the present invention, examples and the like will be given below, but the present invention is not limited to these examples in any way. Unless otherwise specified, "parts" represent parts by mass, and each physical property value in the examples and comparative examples was measured according to the following methods.

[0059] (1) Intrinsic viscosity: [η] In the case of polyester fibers, 0.12 g of fiber (polymer) sample was dissolved in 10 mL of a tetrachloroethane / phenol mixed solvent (volume ratio 1 / 1), and the intrinsic viscosity (dL / g) at 35 °C was measured.

[0060] (2) As-spun yarn quality The as-spun yarn quality was evaluated by the number of spinning breaks, the coefficient of variation of fiber diameter, and the viscosity difference of the polymer discharged from each hole arrangement of the spinneret. The number of spinning breaks was calculated from the number of breaks occurred during 8 hours of spinning. In the evaluation of the number of spinning breaks, "spinning impossible" and "processing impossible" refer to the following states where no fiber bundle was obtained.

[0061] (Spinning impossible) (a) The pressure loss in the flow path was too high, the pack pressure rose above the pack pressure resistance, and polymer leakage or spinneret deformation occurred (Comparative Example 1, Comparative Example 3) (i) Due to a small filtration volume, foreign matter remained in the polymer and reached the spinneret holes, resulting in foreign matter clogging and poor discharge (Comparative Example 5) (iii) Due to a large filtration volume, a polymer retention area occurred in the pack, and poor discharge occurred due to the discharge of the low-viscosity retained polymer (Comparative Example 6) (Processing impossible) (e) Due to a large polymer flow path diameter or a large number of polymer flow paths, it was impossible to manufacture the pack (Comparative Example 2, Comparative Example 4)

[0062] Also, the coefficient of variation of fiber diameter was the value obtained by observing the cross-section of the obtained fiber bundle cut perpendicular to the fiber axis direction with a microscope, measuring the fiber diameters of 100 filaments, and dividing the standard deviation by the average value. Further, the viscosities of the polymers discharged from the outermost row, the central row, and the innermost row of the spinneret were regarded as viscosity spots.

[0063] [Example 1] Using a pack for a spinneret having the configuration shown in Table 1, a spinneret with a radial arrangement of 4004 discharge holes (308 holes × 13 rows, discharge hole diameter 0.18 mm, ratio of hole length to hole diameter of the discharge hole being 1.1, discharge hole compression coefficient 0.051, discharge hole row arrangement coefficient 0.78, hole density 0.55 pieces / mm 2 ) was used. Polyethylene terephthalate (PET) chips with an intrinsic viscosity of 0.64 dL / g were melted at 290 °C, discharged at 0.17 g / min per hole, and cooled air was applied from the inside to the outside of the discharge hole arrangement on the discharge side of the spinneret to obtain a fiber bundle at a winding speed of 1150 m / min.

[0064] [Example 2] In Example 1, a fiber bundle was obtained in the same manner as in Example 1, except that a pack for a spinneret in which the polymer flow path was changed as shown in Table 1 was used.

[0065] [Example 3] In Example 1, a fiber bundle was obtained in the same manner as in Example 1, except that a pack for a spinneret in which the number of polymer flow paths was changed as shown in Table 1 was used.

[0066] [Example 4] In Example 1, a fiber bundle was obtained in the same manner as in Example 1, except that a pack for a spinneret in which the polymer flow path and the number of polymer flow paths were changed as shown in Table 1 were used.

[0067] [Example 5] In Example 1, a fiber bundle was obtained in the same manner as in Example 1, except that the discharge amount of the polymer was changed as shown in Table 1.

[0068] [Example 6] In Example 5, a fiber bundle was obtained in the same manner as in Example 5, except that a pack for a spinneret in which the polymer flow path was changed as shown in Table 1 was used.

[0069] [Example 7] In Example 1, a fiber bundle was obtained in the same manner as in Example 1, except that the discharge amount of the polymer was changed as shown in Table 1.

[0070] [Example 8] In Example 7, a fiber bundle was obtained in the same manner as in Example 7, except that a pack for a spinneret in which the polymer flow path was changed as shown in Table 1 was used.

[0071] [Example 9] In Example 7, a fiber bundle was obtained in the same manner as in Example 7, except that a spinneret in which the number of discharge holes was changed as shown in Table 1 was used.

[0072] [Example 10] In Example 1, a fiber bundle was obtained in the same manner as in Example 1, except that a pack for a spinneret in which the filtration tank volume was changed as shown in Table 1 was used.

[0073] [Comparative Example 1] In Example 1, an attempt was made to carry out the procedure in the same manner as in Example 1, except that a pack for a spinneret in which the polymer flow path was changed as shown in Table 1 was used and the discharge amount of the polymer was changed as shown in Table 1, but the state of (a) occurred and a fiber bundle could not be obtained.

[0074] [Comparative Example 2] In Example 1, an attempt was made to use a pack for a spinneret in which the polymer flow path and the number of flow paths were changed as shown in Table 1, but the state of (e) occurred and a fiber bundle could not be obtained.

[0075] [Comparative Example 3] In Example 1, an attempt was made to carry out the procedure in the same manner as in Example 1, except that a pack for a spinneret in which the number of polymer flow paths was changed as shown in Table 1 was used and the discharge amount of the polymer was changed as shown in Table 1, but the state of (a) occurred and a fiber bundle could not be obtained.

[0076] [Comparative Example 4] In Example 1, an attempt was made to use a pack for a spinneret in which the polymer flow path and the number of polymer flow paths were changed as shown in Table 1, but it was in the state of (e), and no fiber bundle was obtained.

[0077] [Comparative Example 5] In Example 1, an attempt was made to carry out the same procedure as in Example 1 except that a pack for a spinneret in which the filtration tank volume was changed as shown in Table 1 was used and the polymer discharge amount was changed as shown in Table 1, but it was in the state of (a), and no fiber bundle was obtained.

[0078] [Comparative Example 6] In Example 1, an attempt was made to carry out the same procedure as in Example 1 except that a pack for a spinneret in which the filtration tank volume was changed as shown in Table 1 was used and the polymer discharge amount was changed as shown in Table 1, but it was in the state of (u), and no fiber bundle was obtained. The raw yarn qualities of the fiber bundles obtained in the examples and comparative examples are shown in Tables 1 and 2.

[0079]

Table 1-1

[0080]

Table 1-2

[0081]

Table 2

Industrial Applicability

[0082] According to the present invention, since it is possible to provide a spinning apparatus in which the polymer residence area in the pack is small, a compact and highly productive spinning apparatus capable of obtaining yarns of stable quality can be provided, so the industrial applicability is high and its industrial value is extremely large.

Explanation of Signs

[0083] 01 Pack 1 Upper plate 2 Lower plate 3 Base holder 4 Base retainer 5 Filter layer 6 Polymer flow path 7 Wire mesh filter 8 Base 9 Static mixing element 10 Spinning base 11 Ejection hole 12 Predetermined point E within the spinning base 13 Auxiliary line arranged from point E of item 3 to the circumference of the spinning base 14 Circular auxiliary line centered on point E of item 3 15 Introduction part of the thermoplastic resin in item 1 16 Discharge part discharge hole of the thermoplastic resin in item 1 17 Distance between the center of the outermost concentric circle discharge hole of the discharge hole array and the predetermined point within the base: X1 18 Distance between the center of the innermost concentric circle discharge hole of the discharge hole array and the predetermined point within the base: X2 19 Cross-sectional area of the hole in the introduction part of the thermoplastic resin: Y1 20 Cross-sectional area of the hole in the discharge part: Y2 21 Diameter of the hole in the discharge part: Z1 22 Hole length of the hole in the discharge part: Z2 23 Spinning pack body 24 Heat insulating material 25 Cooling medium blowing device 26 Oiling device 27 Take-up roller 28 Cooling medium suction device Ejection holes arranged concentrically in a dn p array (n = 1, 2, ···, p), and the distance between adjacent ejection holes in the p array

Claims

1. A spinning device having a spinneret pack for melt spinning, which is provided with a spinneret in which discharge holes for discharging a polymer in a fibrous form are formed. The spinneret pack is provided with an inflow hole through which the polymer flows in. Downstream of the inflow hole, there is a filtering layer having a volume of 100 to 800 cm ３ for filtering the incoming polymer. Further, downstream of the filtering layer, there are a plurality of polymer flow paths arranged in a circumferential shape. The inner diameter of the polymer flow path is 2.9 to 7.1 mmφ, and the number of the polymer flow paths is 12 to 40. A wire mesh filter and an annular spinneret are provided immediately below the downstream side of the polymer flow path. The spinning device is characterized by this.

2. The spinning device according to claim 1, wherein the distance from the lower end of the polymer flow path to the upper end of the polymer introduction part of the spinneret is 0.1 to 10.0 mm.

3. The spinning device according to claim 1 or 2, which has static mixing elements in the polymer flow path, the number of elements being 2 to 20, and the ratio (L / D) of the length (L) to the diameter (D) per element being 0.3 to 3.

0.

4. The number of discharge holes formed in the spinneret is 2000 to 9000, and the hole density of the discharge holes is 0.15 to 0.85 holes / mm ２ The spinning device according to claim 1 or 2.

5. Among the discharge holes formed in the spinneret, when the distance between the center of the outermost peripheral concentric discharge hole and a predetermined point in the spinneret is X1, and the distance between the center of the innermost peripheral concentric discharge hole in the spinneret and the predetermined point in the spinneret is X2, the discharge hole arrangement coefficient X2 / X1 is 0.40 to 0.

85. The spinning device according to claim 1 or 2.

6. The spinning device according to claim 1 or 2, which has a mechanism for sucking a medium for cooling the yarn from the outside of the discharge holes on the polymer discharge side of the spinneret.

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