JP4498354B2 - A base for wet spinning of acrylic core-sheath composite fiber - Google Patents

Description

  The present invention relates to an improved wet spinning base used in the production of acrylic core-sheath composite fibers.

As a core-sheath composite spinning base, a distribution plate that already has a core component distribution hole and a sheath component distribution hole, a sheath component supply hole that communicates with the sheath component distribution hole, and a plurality of core components that are communicated with the core component distribution hole and dividedly supplied. An upper base plate having a large number of core component supply holes arranged in parallel to each other, and a composite flow discharge hole group having a composite flow discharge hole axially aligned with the core component supply holes of the upper base plate and a composite flow Consists of a lower base plate having a sheath component introduction groove between the discharge hole rows, and a spacer for allowing a sheath component to flow from the sheath component introduction groove to the composite flow discharge hole by forming a gap between the upper base plate and the lower base plate A proposed spinneret has been proposed (see Patent Document 1). This spinneret has a hole density of 50 / cm ² or more, and can have a large number of holes with 3000 or more spinning holes. (See, for example, Patent Document 2), which is easy to manufacture.

However, this spinneret is not particularly problematic when melt-spinning core-sheath composites such as polyester fibers and polyamide fibers, or when wet-spinning acrylic core-sheath composite fibers with a relatively small number of single fibers, but the spinning speed In the case of wet spinning of acrylic core-sheath composite fibers with a large number of single fibers such that the number of single fibers exceeds 5000, it is necessary to use a die with a large number of spinning holes. When the sheath component is joined around the core component flow to form a composite flow, if a plurality of long core component supply holes are arranged in parallel, the sheath component is placed in each composite flow discharge hole. It is difficult to introduce uniformly, and the core-sheath composite fiber having a variation in the core-sheath structure between the single fibers is generated by changing the core-sheath ratio or decentering the core part.
Japanese Patent Laid-Open No. 9-21015 Japanese Patent Laid-Open No. 11-350241

  The present invention is an improvement of the above-mentioned problems in the spinneret, and the object of the present invention is to eliminate the dispersion of the core-sheath composite structure between the single fibers and to improve the uniformity of the core-sheath composite structure. Provides a base for wet spinning of an acrylic core-sheath composite fiber that is capable of stable and wet-spinning core-sheath composite fiber, has a simple structure and is easy to manufacture, and has a spinning hole count of 5000 or more. There is to do.

The present invention is a base for wet spinning of an acrylic core-sheath composite fiber in which at least one of a core component and a sheath component is an acrylonitrile-based polymer, the distribution plate having the core component distribution hole and the sheath component distribution hole, and the core component Core component supply holes that communicate with the distribution holes and divide and supply the core component are arranged in parallel in a plurality of rows, and are divided into quadrangular blocks having a hole density of 100 to 150 / cm ² and a number of holes of 100 to 500 / block, A plurality of blocks are arranged in parallel and in parallel and have core component supply holes with a total number of 5000 to 30000 holes, and the sheath component supply holes communicating with the sheath component distribution holes are arranged at the intersections of the blocks of the core component supply holes The upper base plate and the composite flow discharge holes having the inlet hole diameter larger than the outlet hole diameter of the core component supply hole are arranged as a plurality of blocks at the hole positions corresponding to the core component supply holes of the upper base plate, and the composite flow discharge is performed. Hole A lower base plate having a sheath component inflow groove surrounding the block, a sheath component introduction groove communicating with the sheath component inflow groove and introducing a sheath component between the composite flow discharge hole rows, and an outlet of the core component supply hole of the upper base plate; Acrylic core-sheath composite comprising a spacer for forming a gap for a flow path for allowing the sheath component to flow into the composite flow discharge hole while facing the inlet of the composite flow discharge hole of the lower base plate In the base for wet spinning of fibers.

  According to the present invention, an increase in the number of spinning holes, that is, so-called multi-hole, variation in the core-sheath composite structure between single fibers while the acrylic core-sheath composite fiber has a large number of single fibers of 5000 to 30000. Acrylic core-sheath composite fiber with excellent uniformity can be spun stably and with high productivity, and it can handle a wide range of spinning conditions for various core and sheath components and has a simple structure. Thus, a core-sheath composite spinning die having a high hole density and a large number of holes can be provided.

It is a nozzle perspective view (partial sectional view) of the spinneret of the present invention. It is a partial expanded sectional view which shows the structure of the principal part of the spinneret of this invention. It is the graph showing the top view which shows the range of calculation of an Example, and the result of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheath component supply hole 2 Core component supply hole 3 Upper cap plate 4 Compound flow discharge hole 5 Sheath component inflow groove 6 Sheath component introduction groove 7 Lower cap plate 8 Spacer

Embodiments of the present invention will be described below with reference to the drawings.
The spinneret of the present invention is used when producing an acrylic core-sheath composite fiber by wet spinning, and in particular, in the structure of the base, the upper base plate and the lower base plate disposed via a spacer are structurally structural. Has characteristics. FIG. 1 is a perspective view (partial sectional view) of a nozzle of a spinning die of the present invention, and FIG. 2 is a partially enlarged sectional view showing the structure of the main part of the spinning die of the present invention. In the figure, 1 is a sheath component supply hole, 2 is a core component supply hole, 3 is an upper base plate, 4 is a composite flow discharge hole, 5 is a sheath component inflow groove, 6 is a sheath component introduction groove, 7 is a lower base plate, 8 represents a spacer.

The upper base plate 3 has a core component supply hole 2 that divides and supplies the core component distributed from the core component distribution hole of the distribution plate laminated on the upper base plate, and the core component supply hole has a plurality of linear shapes. Further, this core component supply hole row is arranged in parallel to a plurality of rows, and is a substantially rectangular quadrangular block having a hole density of 100 to 150 holes / cm ² and a hole number of 100 to 500 holes, preferably 100 to 300 holes. Is forming. When forming the block by arranging the core component supply hole rows in parallel in a plurality of rows, the arrangement of the different hole numbers is arranged in a plurality of rows so that the positions of the core component supply holes in the adjacent rows are shifted and staggered. It is preferable to arrange them in parallel or in multiple rows with the same number of holes alternately shifted in position.

  The upper base plate is provided with 20 to 60, preferably 25 to 40, blocks of core component supply holes. The total number of core components is 5,000 to 30,000, preferably 6,000 to 10,000. Make a hole. The arranged blocks are preferably a combination of blocks having the same number of holes, but may be a combination of blocks having different numbers of holes depending on the shape of the base plate, the mounting method, and the like. In the block of one core component supply hole, the number of the core component supply holes arranged in parallel is not particularly limited, but the number of the core component supply hole in one row is 10 to 20 pieces. It is preferable for forming a uniform core-sheath composite flow. The core component supply hole in the upper base plate has an inlet hole diameter of 300 to 500 μm and an outlet hole diameter of 50 to 90 μm. The core component is discharged and supplied from the core component supply hole as a stable linear core component flow. Preferred above.

  The core component supply hole blocks need to be arranged as evenly as possible on the base plate. In order to increase the number of holes, a plurality of blocks are arranged in parallel and in parallel. From the viewpoint of drilling holes, the base plate is preferably square. Further, the upper base plate 3 has the sheath component supply holes 1 communicating with the sheath component distribution holes at positions corresponding to the corners of the quadrangle that are the intersections of the square blocks of the core component supply holes. The sheath component supply hole 1 in the upper base plate 3 preferably has a hole diameter of 2.0 to 4.0 mm in order to supply the sheath component uniformly and promptly.

The lower base plate 7 is a base plate having the same shape as the upper base plate overlapped with the upper base plate 3 through the spacer 8, and the core component is supplied to the hole positions corresponding to the core component supply holes 2 of the upper base plate 3. The composite flow discharge hole 4 having an inlet hole diameter larger than the outlet hole diameter of the hole is disposed. Accordingly, the composite flow discharge hole 4 has a hole density of 100 to 150 / cm ² corresponding to the core component supply hole as a plurality of blocks. The number of holes is 100 to 500 / block, preferably 100 to 300 / block, the total number of holes is 5000 to 30000, preferably 6000 to 10000, and the lower base plate 7 is a composite flow discharge on the plate surface. A sheath component inflow groove 5 that surrounds each block of the holes and communicates vertically and horizontally and a sheath component introduction groove 6 that communicates with the sheath component inflow groove and introduces a sheath component between the composite flow discharge hole rows in each block are provided.

The composite flow discharge hole 4 in the lower base plate 7 is a hole that forms and discharges a composite flow of a core component and a sheath component, and has at least an inlet hole diameter of 300 to 500 μm and an outlet hole diameter of 50 to 90 μm. It is preferable when discharging as a stable core-sheath composite flow. Further, the sheath component inflow groove 5 surrounding the block of the composite flow discharge hole 4 has a groove width of 2.0 to 5.0 mm, and the sheath component introduction groove 6 for introducing the sheath component between the composite flow discharge hole rows in the block is In order to form a stable core-sheath composite flow, the groove width is preferably 0.3 to 1.0 mm. The sheath component introduction groove 6 may be further provided at an appropriate position of the composite flow discharge hole array so as to be orthogonal to the hole array.

  In the spinning die shown in FIG. 1, the core component is led from the core component distribution hole of the distribution plate to each core component supply hole 2 arranged as a block of the core component supply hole of the upper base plate 3, and the core component supply hole. 2 is supplied toward the inlet portion of the composite flow discharge hole 4 as a linear discharge flow. The sheath component is supplied from the sheath component distribution hole of the distribution plate to the sheath component inflow groove 5 surrounding the block of the composite flow discharge hole 4 of the lower base plate 7 through the sheath component supply hole 1 of the upper base plate 3, and the sheath component inflow It is led from the groove 5 to the sheath component introduction groove 6 between the composite flow discharge hole rows in each block, mainly overflows from the sheath component introduction groove 6 and further sandwiched between the upper base plate 3 and the lower base plate 7. , The pressure is lost, and the flow is rectified and supplied uniformly to each composite flow discharge hole 4. The sheath component flow thus rectified flows into the composite flow discharge hole 4 while wrapping the core component flow supplied as the discharge flow from the outlet of the core component supply hole 2 from the surroundings, and becomes a core-sheath composite flow to be a composite flow discharge. It is discharged from the outlet of the hole 7. The gap between the upper base plate 3 and the lower base plate 7 is set to an arbitrary width by the spacer 8.

  The first feature of the present invention is that the sheath component is uniformly introduced into each composite flow discharge hole in which the core component is supplied as a discharge flow by providing the core component supply hole and the composite flow discharge hole in a block form. It is that a simple core-sheath composite flow can be formed. In order to produce an acrylic core-sheath composite fiber by wet spinning with high productivity, it is necessary to increase the number of composite flow discharge holes through which the core-sheath composite flow is discharged. As a result, variations occur between the core-sheath composite flows formed by the respective composite flow discharge holes, and variations in the core-sheath composite structure between single fibers are likely to occur. However, according to the present invention, by arranging the core component supply hole and the composite flow discharge hole in a block form, a wet core-sheath composite spinneret having a uniform core-sheath composite flow and a number of spinning holes of 5000 to 30000 is achieved. It is possible to increase the number of holes.

  The second feature of the present invention is that the spinneret is economical while the number of core component supply holes provided in the upper die plate and the number of composite flow discharge holes provided in the lower die plate are 5000 to 30000 respectively. Also, it can be advantageously obtained. In order to improve the productivity of the spinneret, it is also important that the base itself is easy to manufacture and can be obtained economically at a low cost. Normally, a base for wet spinning of fibers has a relatively low pressure at the time of discharge, so that the thickness of the base plate is thin, and the discharge hole is easily drilled. On the other hand, in a base for wet spinning of a composite fiber, particularly a core-sheath composite fiber, the spinning solution of the sheath component is rectified by giving a large pressure loss when passing through a narrow gap, so that the base plate can only withstand this pressure. Thickness is required, which increases the cost of drilling the discharge holes. Therefore, in the base for wet spinning of the core-sheath composite fiber, it is not possible to expect a substantial reduction in the manufacturing cost of the base unless the total number of holes is suppressed.

  However, in the spinneret of the present invention, the upper base plate is made only by drilling the core component supply hole and the sheath component supply hole if the upper surface and the lower surface are flat, and the lower base plate is If the lower surface is made flat, it is produced by drilling the composite flow discharge holes, straight grooving of the sheath component inflow grooves on the plate surface, and the sheath component introduction grooves between the composite flow discharge hole arrays. Therefore, particularly when the core component supply hole and the composite flow discharge hole have the same shape, the upper base plate is formed by drilling the sheath component supply hole in one of the two base plates that have been drilled in the same manner. The lower base plate can also be manufactured by grooving the sheath component inflow groove and the sheath component introduction groove, and the manufacture of the base of the present invention is relatively inexpensive and economical. . In the spinning die of the present invention, the upper die plate and the lower die plate can be thinned to about 5 mm, depending on the hole diameter, the number of holes, the supply pressure, the material, etc. This makes it easy to clean as well as lighter.

  The third feature of the present invention is that the gap formed between the upper base plate and the lower base plate can be arbitrarily changed by interposing spacers having different thicknesses. In core-sheath composite spinning, the distance between the upper base plate and the lower base plate usually needs to be small if the viscosity of the sheath component is low, and large if the viscosity is high. This interval is set to an optimum value according to various spinning conditions such as the types and combinations of the core component and the sheath component, the concentration, the discharge amount, the discharge amount ratio (core-sheath ratio), and the spinning temperature. In the base of the present invention, the interval can be easily changed in the range of 30 to 500 μm simply by replacing a spacer having a thickness of usually 0.03 to 0.5 mm, which can be manufactured at low cost. This makes it possible to meet a wide range of spinning conditions and is extremely economical.

  The spinning die of the present invention is used as a die for producing an acrylic core-sheath composite fiber in which both or one of the core component and the sheath component is an acrylonitrile polymer by wet spinning. In addition, the spinning die of the present invention can produce an acrylic core-sheath composite fiber having various functions and performances with a combination of a core component and a sheath component with high productivity by increasing the number of holes. In the case where the core component and the sheath component are acrylonitrile-based polymers, different combinations of physical properties, functionality, and the like are used. The polymer used as the core component or sheath component in addition to the acrylonitrile polymer may be any polymer that can be wet-spun, and examples thereof include a vinyl chloride polymer and a cellulose polymer.

A spinning nozzle divided into a square block of 280 holes / block and a spinning nozzle divided into a square block of 750 holes / block from the composite flow discharge hole under the conditions shown in Table 1. The discharge amount distribution of the discharged spinning solution was calculated using the following formula (assuming the discharge amount of the hole farthest from the sheath component supply hole).
The calculation was performed for a range of 1/4 of one block having one sheath component supply hole (the hatched portion in FIG. 3). The results are shown in FIG. 3 and the CV values are shown in Table 2.

Circular pipe flow loss type ΔP = 128ηQL / d ⁴ π
Rectangular channel pressure loss equation ΔP = 64ηab ³ x
Parallel disk flow path pressure drop equation ΔP = 6ηQL _n (r ₂ / r ₁ ) / h ³ π

here,
ΔP: Pressure loss (kg / m ³ )
η: Viscosity (kg · sec / m ² )
Q: Discharge rate (m ³ / sec)
L: Length (m)
d: Pipe inner diameter (m)
a: Rectangular long side (m)
b: Rectangular short side (m)
x: coefficient h: parallel disk distance (m)
r ₂ : Disc outer radius (m)
r ₁ : radius in disk (m)

  As is apparent from the results in Table 2, the former is more effective for the spinning nozzles divided into 280 holes / block square blocks and the spinning nozzles divided into 750 holes / block square blocks. It can be seen that the discharge variation is small. This variation in the discharge amount results in a variation in the fineness (thickness) of the formed fiber, and if this variation is large, there will be a problem in the texture and appearance of the fiber product.

  When the spinneret of the present invention has a spinning hole number of 5000 to 30000, an acrylic core-sheath composite fiber having a large number of single fibers of 5000 to 30000 is industrially produced by wet spinning. If at least one of the core component and the sheath component is an acrylonitrile-based polymer, polyester fibers or polyamide fibers by melt spinning can be used by using various polymers or functional polymers for the core component or the sheath component. This makes it possible to produce various acrylic core-sheath composite fibers that exhibit performance unique to acrylic fibers, which cannot be obtained with the core-sheath composite fibers, by wet spinning without any particular increase in production cost. In particular, when the sheath component is an acrylonitrile-based polymer, it is possible to produce an acrylic core-sheath composite fiber having various functions provided by the core component while maintaining the sharpness unique to the acrylic fiber.

Claims (1)

A base for wet spinning of an acrylic core-sheath composite fiber in which at least one of a core component and a sheath component is an acrylonitrile-based polymer, a distribution plate having a core component distribution hole and a sheath component distribution hole, and a core component distribution hole The core component supply holes for dividing and supplying the core components are arranged in parallel in a plurality of rows, and are divided into quadrangular blocks having a hole density of 100 to 150 / cm ² and a number of holes of 100 to 500 / block. An upper base having a core component supply hole with a total number of 5000 to 30000 holes arranged in parallel and in parallel, and a sheath component supply hole communicating with the sheath component distribution hole arranged at a block intersection of the core component supply holes The composite flow discharge hole having a larger inlet hole diameter than the outlet hole diameter of the core component supply hole is arranged as a plurality of blocks at the hole positions corresponding to the core component supply holes of the plate and the upper base plate, and the block of the composite flow discharge hole A lower base plate having a sheath component inflow groove and a sheath component introduction groove communicating with the sheath component inflow groove and introducing a sheath component between the composite flow discharge hole rows, and an outlet and a lower base of the core component supply hole of the upper base plate An acrylic core-sheath composite fiber comprising a spacer that forms a gap for a flow path for allowing a sheath component to flow into the composite flow discharge hole while facing the inlet of the composite flow discharge hole of the plate A base for wet spinning.

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