Polymer filter, center post for polymer filter, and method for manufacturing polymer molded articles

Abstract

We offer an internal flow type center post that can reduce polymer degradation. [Solution] The container body has a polymer inlet, an inlet channel, and a storage space, and a disc-shaped filter and a center post 30 are housed in the storage space. The center post 30 is a hollow cylindrical body, and in the axial direction, the upstream end is closed, and the side wall facing the disc filter has a plurality of through holes, the plurality of through holes are polymer inlets, and in the axial direction, the downstream end is open, this opening is a polymer outlet, and the through hole located furthest upstream on the side wall is an inclined through hole. The inclined through hole is inclined toward the upstream end of the hollow cylindrical body, and the inclination angle defined by the axis of the inclined through hole and the axis of the hollow cylindrical body is 0° or more and less than 90°, an internal flow type center post 30.

Description

[Technical Field]

[0001] The present invention relates to a polymer filter, a center post for a polymer filter, and a method for manufacturing a polymer molded article. [Background technology]

[0002] When manufacturing polymer molded articles such as yarn and film, the polymer is melted, and after removing foreign matter by filtering the molten polymer, it is subjected to the molding process. A polymer filter is generally used for filtering the polymer. The polymer filter has a container in which a disc-shaped filter and a center post supporting it are arranged. When molten polymer is introduced into the polymer filter container from an inlet, the molten polymer flows through the inlet channel to the disc-shaped filter. The polymer filtered by passing through the disc-shaped filter then flows into the center post and is discharged from the outlet via the center post for use in molding (Patent Documents 1 and 2).

[0003] The aforementioned center post has an internal flow type configuration (Patent Document 1). A specific example will be described using the polymer filter, where the side into which the polymer is introduced is the upstream side and the side from which the polymer is discharged is the downstream side. That is, the internal flow type center post is a hollow cylindrical body, with the upstream end closed and the downstream end open, and the side wall of the hollow cylindrical body has a plurality of through holes that communicate with the internal space. When the internal flow type center post is used, the polymer filtered by the disc-type filter is introduced from the outer surface of the center post through the plurality of through holes in the side wall into the internal space of the center post, moves to the downstream side, and is discharged from the downstream end (opening). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 6793054 [Overview of the project] [Problems that the invention aims to solve]

[0005] When using the polymer filter equipped with the internal flow type center post, the resin may degrade and be discharged for reasons unknown. Using degraded resin in polymer molding can lead to a decrease in the quality of the molded product.

[0006] Therefore, the present invention aims to provide an internal flow type center post that can reduce polymer degradation. [Means for solving the problem]

[0007] To achieve the above objective, the polymer filter of the present invention is Includes the container body, a disc-shaped filter, and a center post; The container body is It has a polymer inlet, an inlet channel communicating with the inlet, and a containment space communicating with the inlet channel. The disk-type filter and the center post are housed in the aforementioned housing space; The aforementioned disk-type filter is It has a through hole in the center, With the center post inserted into the through hole, the container is housed in the storage space of the container body; The aforementioned center post is, It is a hollow cylindrical body, In the axial direction, the upstream end is closed. The side wall facing the disk filter has a plurality of through holes, and these plurality of through holes are polymer inlets. In the axial direction, the downstream end is open, and this opening is the outlet for the polymer. In the aforementioned side wall, the through-hole located on the upstream side is an inclined through-hole. The inclined through-hole is inclined toward the upstream end of the hollow cylindrical body, and the inclination angle defined by the axis of the inclined through-hole and the axis of the hollow cylindrical body is 0° or more and less than 90°.

[0008] The center post for polymer filters of the present invention is It is a hollow cylindrical body, In the axial direction, the upstream end is closed. The side wall has multiple through holes, and these multiple through holes are polymer inlets. In the axial direction, the downstream end is open, and this opening is the outlet for the polymer. In the aforementioned side wall, the through-hole located on the upstream side is an inclined through-hole. The inclined through-hole is inclined toward the upstream end of the hollow cylindrical body, and the inclination angle defined by the axis of the inclined through-hole and the axis of the hollow cylindrical body is 0° or more and less than 90°. This invention is characterized by being used in the polymer filter described above.

[0009] The method for producing a polymer molded article of the present invention is: A step of filtering a molten polymer using the polymer filter of the present invention, and The method is characterized by including a step of molding the molten polymer after filtration. [Effects of the Invention]

[0010] According to the polymer filter of the present invention, it is possible to reduce the deterioration of the polymer introduced into the center post. The inventors have found that, according to a polymer filter provided with an internal flow type center post, the introduced polymer deteriorates due to staying inside. And, in contrast to this, it has been found that by making the through hole located on the most upstream side in the center post an inclined through hole, it is possible to reduce the retention of the resin inside. Therefore, according to the polymer filter of the present invention, by reducing the retention of the polymer, the deterioration of the polymer can be suppressed. Further, when the polymer deteriorates and polymer molding is performed using it, for example, problems such as burns, discoloration, black spots, carbides, fish eyes, and streaks, uneven film thickness, generation of gel lumps, and reduction in the yield rate due to deterioration of physical properties may occur. Therefore, according to the present invention, since the deterioration of the polymer can be suppressed, for example, such problems due to using a deteriorated resin can also be suppressed.

Brief Description of Drawings

[0011] [Figure 1] FIG. 1 is a schematic view showing an example of a polymer filter. [Figure 2] FIG. 2 is a perspective view showing an example of a disk type filter. [Figure 3A] FIG. 3A is a perspective view showing an example of a center post. [Figure 3B] FIG. 3B is a side view of the center post of FIG. 3A. [Figure 4A] FIG. 4A is a partial cross-sectional view of the center post of FIG. 3B, specifically, a partial cross-sectional view of the center post 30 along the axial direction of the hollow cylinder. [Figure 4B] FIG. 4B is a partial cross-sectional view of the center post of FIG. 3B, specifically, a partial cross-sectional view of the center post 30 along the direction orthogonal to the axial direction of the hollow cylinder. [Figure 5] FIG. 5 is the same partial cross-sectional view of the center post as FIG. 4A. [Figure 6]Figure 6 is a partial cross-sectional view showing an example of a conventional center post. [Figure 7] Figure 7 is a partial cross-sectional view showing another example of a center post. [Figure 8] Figure 8 is a schematic diagram of the internal flow path model of Example 1. [Figure 9A] Figure 9A is a schematic diagram of the internal flow path model for Comparative Example 1. [Figure 9B] Figure 9B is a schematic diagram of the internal flow path model for Comparative Example 1. [Figure 10] Figure 10 is a graph showing the shear rate distribution at the X coordinate (Z=0). [Figure 11] Figure 11 is a schematic diagram of the internal flow path model for Comparative Example 1 and the internal flow path model for Example 1. [Figure 12A] Figure 12A is a schematic diagram of the internal flow path model of Example 2. [Figure 12B] Figure 12B is a schematic diagram of the internal flow path model for Comparative Example 2. [Figure 13] Figure 13 is a graph showing the shear rate distribution at the Y coordinate (Z=0). [Figure 14] Figure 14 is a schematic diagram of the internal flow path model for Example 2 and the internal flow path model for Comparative Example 2. [Figure 15] Figure 15 is a schematic diagram showing the positional relationship of through-holes in the internal flow channel model of Example 2 and in the internal flow channel model of Comparative Example 2. [Figure 16] Figure 16 is a graph showing the shear rate distribution at the Y coordinate (Z=0). [Figure 17] Figure 17 is a schematic diagram showing the positional relationship of through-holes in the internal flow channel model of Example 3 and in the internal flow channel model of Comparative Example 3. [Figure 18] Figure 18 is a graph showing the shear rate distribution at the Y coordinate (Z=0). [Figure 19] Figure 19 shows photographs and schematic diagrams of the external shapes of the resin models of Example 5 and Comparative Example 5. [Figure 20A]Figure 20A shows the fluid introduction state into the resin model of Example 5 under condition 1 (white to red). [Figure 20B] Figure 20B shows the fluid introduction state into the resin model of Comparative Example 5 under condition 1 (white to red). [Figure 21A] Figure 21A shows the fluid introduction state into the resin model of Example 5 under condition 2 (red to white). [Figure 21B] Figure 21B shows the fluid introduction state into the resin model of Comparative Example 5 under condition 2 (red to white). [Figure 22] Figure 22 shows an enlarged view of the resin model (60 seconds) of Example 5 in Figure 20A, and an enlarged view of the resin model (60 seconds) of Comparative Example 5 in Figure 20B. [Modes for carrying out the invention]

[0012] The invention includes, for example, the following forms: [1] Includes a container body, a disc-shaped filter, and a center post; The container body is It has a polymer inlet, an inlet channel communicating with the inlet, and a containment space communicating with the inlet channel. The disk-type filter and the center post are housed in the aforementioned housing space; The aforementioned disk-type filter is It has a through hole in the center, With the center post inserted into the through hole, the container is housed in the storage space of the container body; The aforementioned center post is, It is a hollow cylindrical body, In the axial direction, the upstream end is closed. The side wall facing the disk filter has a plurality of through holes, and these plurality of through holes are polymer inlets. In the axial direction, the downstream end is open, and this opening is the outlet for the polymer. In the aforementioned side wall, the through-hole located on the upstream side is an inclined through-hole. The inclined through-hole is inclined toward the upstream end of the hollow cylinder, and the inclination angle defined by the axis of the inclined through-hole and the axis of the hollow cylinder is 0° or more and less than 90°. A polymer filter characterized by the following features. [2] The polymer filter according to [1], wherein the inclination angle of the inclined through hole in the center post is 30 to 85°. [3] The polymer filter according to [1] or [2], wherein the number of inclined through holes located on the most upstream side of the center post is 2 to 20. [4] The polymer filter according to any one of [1] to [3], wherein the center post has 2 to 20 through holes from the upstream side, which are inclined through holes that are inclined toward the upstream end of the hollow cylindrical body. [5] In the center post, The aforementioned inclined through-holes are two or more, The polymer filter according to any one of [1] to [4], wherein the hollow upstream end of the hollow cylindrical body is the confluence region of the inclined through-holes. [6] In the center post, The aforementioned inclined through-holes are two or more, The polymer filter according to any one of [1] to [5], wherein the angle defined by the relative axes of the inclined through holes is 25 to 170°. [7] In the center post, The aforementioned inclined through-holes are two or more, The polymer filter according to any one of [1] to [6], wherein the angle defined by the mutual axes of two inclined through holes that are opposite each other with respect to the axis of the hollow cylindrical body is 25 to 170°. [8] In the center post, The aforementioned inclined through-holes are two or more, The polymer filter according to any one of [1] to [7], wherein the hollow upstream end of the hollow cylindrical body is the confluence region of the inclined through-holes. [9] In the center post, The aforementioned inclined through-holes are two or more, The polymer filter according to [8], wherein adjacent inclined through holes are in contact at their respective ends on the confluence region side.

[10] In the center post, The aforementioned inclined through-holes are two or more, The polymer filter according to any one of [1] to [9], wherein the angle defined by the mutual axes of the two inclined through holes that are opposite each other with respect to the axis of the hollow cylindrical body is 25 to 170°.

[11] The hollow of the hollow cylindrical body is cylindrical, The polymer filter according to any one of [1] to

[10] , wherein the hollow inside the through hole is cylindrical.

[12] It is a hollow cylindrical body, In the axial direction, the upstream end is closed. The side wall has multiple through holes, and these multiple through holes are polymer inlets. In the axial direction, the downstream end is open, and this opening is the outlet for the polymer. In the aforementioned side wall, the through-hole located on the upstream side is an inclined through-hole. The inclined through-hole is inclined toward the upstream end of the hollow cylindrical body, and the inclination angle defined by the axis of the inclined through-hole and the axis of the hollow cylindrical body is 0° or more and less than 90°. For use in polymer filters described in any one of items [1] to

[11] A center post for polymer filters characterized by the following features.

[13] A step of filtering the molten polymer using a polymer filter described in any one of the items [1] to

[11] , and This includes a step of molding the molten polymer after filtration. A method for producing a polymer molded article, characterized by the above.

[0013] Unless otherwise specified, terms used herein may be used in the sense commonly used in the art.

[0014] The present invention will be described below with specific examples, but it is not limited to these examples. Furthermore, the examples in each invention can be used interchangeably with each other.

[0015] [Polymer filter] As described above, the polymer filter of the present invention Includes the container body, a disc-shaped filter, and a center post; The container body is It has a polymer inlet, an inlet channel communicating with the inlet, and a containment space communicating with the inlet channel. The disk-type filter and the center post are housed in the aforementioned housing space; The aforementioned disk-type filter is It has a through hole in the center, With the center post inserted into the through hole, the container is housed in the storage space of the container body; The aforementioned center post is, It is a hollow cylindrical body, In the axial direction, the upstream end is closed. The side wall facing the disk filter has a plurality of through holes, and these plurality of through holes are polymer inlets. In the axial direction, the downstream end is open, and this opening is the outlet for the polymer. In the aforementioned side wall, the through-hole located on the upstream side is an inclined through-hole. The inclined through-hole is inclined toward the upstream end of the hollow cylindrical body, and the inclination angle defined by the axis of the inclined through-hole and the axis of the hollow cylindrical body is 0° or more and less than 90°.

[0016] In the present invention, the direction from the inlet to the outlet of the polymer filter is, for convenience, referred to as the polymer flow direction, and in the flow direction, the inlet side is referred to as the upstream side, and the outlet side as the downstream side. In the present invention, the axial direction of the center post is, for example, the same direction as the flow direction.

[0017] Of the multiple through holes in the aforementioned center post, the through hole located furthest upstream will hereafter be referred to as the "upstreamest through hole" or the "first through hole."

[0018] Specific examples of the present invention will be described below with reference to the figures. In each figure, the same parts are denoted by the same reference numerals. Figures enclosed by dotted lines indicate partial drawings. The present invention is not limited in any way by the embodiments described below. Unless otherwise specified, the descriptions of each embodiment can be used interchangeably with each other.

[0019] (Embodiment 1) A schematic diagram of the basic configuration of the polymer filter of this embodiment is shown in Figure 1. Note that in Figure 1, the details of the through-holes (including the inclined through-holes) in the side wall of the center post are omitted and will be described later using other figures.

[0020] Figure 1 is a schematic diagram of polymer filter 1, showing some of its components in cross-sectional view. Figure 1 is intended to explain the positional relationships of the components of polymer filter 1 and the flow of polymer, and is not limited to this configuration.

[0021] The polymer filter 1 includes a container 10 (container body 101, container base 102), a disc-shaped filter 20, and a center post 30. In Figure 1, arrow F indicates the direction from the polymer inlet to the polymer outlet in the polymer filter 1, and this is referred to as the polymer flow direction throughout the polymer filter 1. In the polymer filter 1, the container body 101 side is the upstream side, and the container base 102 side is the downstream side. Also in Figure 1, the dotted arrows indicate the direction of polymer flow at each part.

[0022] The container body 101 has a polymer inlet 11, an inlet channel 14 communicating with the inlet 11, and a storage space 13 communicating with the inlet channel 14. In the container body 101, the downstream side of the storage space 13 is an opening 13a. The storage space 13 of the container body 101 houses the upstream side of the disc-type filter 20 and the center post 30. The container base 102 has a through hole in the flow direction F into which the downstream side of the center post 30 is inserted. The container base 102 and the center post 30 may be integrated on the downstream side of the center post 30. The opening 13a of the storage space 13 of the container body 101 is closed by the container base 102 acting as a lid. In the polymer filter 1, the opening 34 at the downstream end of the center post 30 is the polymer outlet 34.

[0023] The disc-type filter 20 includes multiple filtration elements 21. An example of the disc-type filter 20 is shown in a perspective view in Figure 2. As shown in Figure 2, the disc-type filter 20 is made up of multiple filtration elements 21 stacked on top of each other via spacers 22. Each filtration element 21 is disc-shaped with a hole 211 in the center, and the filtration elements 21 are stacked with their holes 211 aligned. Therefore, the disc-type filter 20 has a through hole 23 in the center along the stacking direction of the filtration elements 21. In the polymer filter 1, the center post 30 is inserted into the through hole 23 of the disc-type filter 20. The disc-type filter 20 is also called, for example, a leaf disc filter (LDF).

[0024] The filtration element 21 consists of, for example, two donut-shaped filtration members with a hole in the center, which are stacked facing each other via a support member. The outer circumferences of the two donut-shaped filtration members are fixed to each other, and the inner circumferences of the two donut-shaped filtration members are also fixed to each other. The filtration members only need to be able to filter molten polymer, and a specific example is a porous sintered body. The raw material of the sintered body is not particularly limited and can be, for example, metal or ceramic. The support member can be, for example, a metal mesh member.

[0025] According to the disc-type filter 20 having a filtration element 21, for example, a polymer is filtered by passing from the outside to the inside of the filtration element 21. The filtered polymer passes through the inside of the filtration element 21 and is led out of the disc-type filter 20 through the central hole 211 (through hole 23 of the disc-type filter 20).

[0026] Figures 3, 4, and 5 show an example of the basic structure of the internal flow type center post 30 (also called the center pole). Figure 3A is a perspective view of the center post 30, and Figure 3B is a side view of the center post 30. For convenience, in the side view of Figure 3B, the through-hole 32 is shown only in the front side wall 31a, and the through-holes in the other side walls are not shown. Figures 4A and 4B are partial cross-sectional views of the center post 30, extracted from the dotted line area in Figure 3B. Specifically, Figure 4A is a partial cross-sectional view of the center post 30 along the axial direction of the hollow cylindrical body, i.e., a partial cross-sectional view in direction II in Figure 3B, and Figure 4B is a partial cross-sectional view of the center post 30 along the direction perpendicular to the axial direction of the hollow cylindrical body, i.e., a cross-sectional view in the direction II-II in Figure 3B. Figure 5 is the same partial cross-sectional view as Figure 4A.

[0027] As described above, the center post 30 is a hollow cylindrical body and has a hollow internal flow path 33 that runs axially within it. The center post 30 has a closed end on the upstream side (the upstream end of the internal flow path 33) and an open end on the downstream side (the downstream end of the internal flow path 33) (opening 34). In the internal flow path 33, the upstream side is a tapered region 331 where the diameter changes, that is, a region that narrows towards the upstream side, while the downstream side is a region where the diameter does not change much.

[0028] The center post 30 has a plurality of through holes 32 in the side wall 31 of the hollow cylindrical body that communicate with the internal flow path 33 of the hollow cylindrical body. The through holes 32 are also referred to as communication flow paths below. As shown in Figure 3A, the center post 30 of this embodiment has an upstream portion 303, an intermediate portion 302, and a downstream portion 301 along the axial direction, and the side wall of the intermediate portion 302 has a plurality of through holes 32.

[0029] The external shape of the center post 30 is not particularly limited, and the upstream portion 303, intermediate portion 302, and downstream portion 301 may have the same shape or different shapes. In this embodiment, the external shape of the center post is cylindrical for the upstream portion 303 and downstream portion 301, and rectangular for the intermediate portion 302. Hereinafter, unless otherwise specified, the shape of the center post 30 and the hollow cylindrical body refers to the shape of the intermediate portion 302. In this embodiment, the external shape of the center post 30 (intermediate portion 302) is a hexagonal prism having six side walls 31 (31a, 31b, 31c, 31d, 31e, 31f), each side wall 31 having a through hole 32, and the internal shape of the center post 30 is cylindrical.

[0030] In the center post 30, the number of through holes 32 is not particularly limited, but is two or more. The internal shape of the through holes 32 is not particularly limited, and is, for example, cylindrical, and in this embodiment, it is a cylinder whose internal diameter does not change in the axial direction.

[0031] In the center post 30, the through hole located furthest upstream is called the first through hole. In the center post 30, there may be one first through hole, or there may be two or more as described later, and at least one of the first through holes is an inclined through hole. In the center post 30, the first through hole means, for example, that there is no passage through which resin flows into the internal passage 33 upstream of the communication portion between the first through hole and the internal passage 33.

[0032] In this embodiment, the "inclined through-hole" is a through-hole provided in the side wall of the center post 30, communicating with the interior, and inclined toward the upstream end of the hollow cylindrical body. More specifically, it is a through-hole that is inclined toward the upstream end of the hollow body, based on a state in which the through-hole is provided perpendicular to the axis of the hollow cylindrical body. The internal flow path 33 of the hollow cylindrical body (the tip of the tapered region 331) and the interior of the first through-hole 321 merge in the region of the dotted circle E in Figure 4A, so region E is also called the merging region E. Furthermore, since the merging region E is curved due to the inclination of the first through-hole 321, it is also called the curved region E.

[0033] The inclination angle (θ) of each through-hole 32 of the center post 30 can be defined, for example, by the axis (axisH) of the through-hole and the axis (axisF) of the hollow cylindrical body.

[0034] In this embodiment, in Figures 3A and 3B, the upstreammost through-hole in the side wall 31a is described as the first through-hole 321 of the center post 30. The first through-hole 321 of the center post 30 is an inclined through-hole that slopes toward the upstream end of the hollow cylindrical body. As shown in Figure 5, the inclination angle θ of the first through-hole 321 can be defined by the axis (axis H) of the first through-hole and the axis (axis F) of the hollow cylindrical body. The inclination angle θ of the first through-hole 321 is 0° or more and less than 90°. The inclination angle θ has a lower limit of 0° or more, preferably greater than 0° and 10°, 20°, 30°, or 40°, and an upper limit of less than 90°, preferably 85°, 80°, 70°, or 60°. The range is, for example, greater than 0° and less than 90°, 10~85°, 20~85°, 30~85°, 30~70°, 40~60°, 45~60°, 45~55°, 50±10°, or 50±5°.

[0035] Here, we will describe a conventional center post. Figure 6 shows a partial cross-sectional view of a conventional center post 40. Figure 6, like Figure 5, is a cross-sectional view of the area corresponding to the dotted line area in Figure 3B. As shown in Figure 6, in the center post 40, of the multiple through holes 32 provided in the side wall of the hollow cylindrical body, the upstream through hole 421 is provided at a right angle (90°) to the axis of the hollow cylindrical body. As a result of diligent research, the inventors have found that because the through hole is provided at a right angle to the axis of the hollow cylindrical body, the resin introduced into the hollow cylindrical body through the through hole accumulates. Specifically, because the through hole 421 (connecting channel) and the internal channel 33 of the hollow cylindrical body are connected in an orthogonal positional relationship, the resin accumulates in the area E of the dotted line frame in Figure 6. It also became clear that this accumulation of resin causes the aforementioned problem of resin degradation. In contrast, in the present invention, as described above, by making the upstream through-hole (first through-hole) 321 of the center post 30 an inclined through-hole, stagnation can be reduced.

[0036] Furthermore, through further investigation, the inventors found that the reduction in resin retention caused by making the first through-hole an inclined through-hole can be evaluated by the shear rate. The shear rate and shear stress of the fluid are defined as follows. Shear stress: Definition: The force exerted on the surface X of an object placed on a substrate when the surface X of the object is pushed and shifted. Shear stress τ = F / A A: Area of ​​the shifted surface X on the object (unit: m) 2 ) F: Force applied to shift surface X (unit: N)

[0037] Shear rate: When a force F displaces the surface X of an object, the velocity gradient (degree of displacement) is such that the surface X at a height H from the substrate is displaced at a velocity V.

number

[0038] As shown in the above formula, shear stress is proportional to the shear rate. Therefore, the greater the shear rate, the greater the shear stress. In other words, the greater the shear rate, the greater the force that displaces the object. When a fluid passes through a channel, the walls of the channel correspond to the substrate and the fluid corresponds to the object, so it can be said that the fluid is less likely to stagnate in the channel. Also, the fluid velocity is v0=0 at the channel wall in contact with the fluid, and the fluid velocity v at a position at a small distance Δh away from the wall h As shown in the above formula, this is proportional to the shear rate. Therefore, the greater the shear rate, the greater the flow velocity v near the wall surface. h The shear rate increases, and it can be said that fluid is less likely to stagnate in the aforementioned flow path. Therefore, by analyzing the shear rate of the center post of the present invention, the reduction in fluid stagnation can be evaluated.

[0039] The aforementioned object is a card (area Amm²) 2 When the object is represented by a stack of objects, when the object is pushed and shifted with a force of F (N), the force acting on the shifting surface is the shear stress τ = F / A, and when the object is shifted with a force of F (N), the velocity gradient (degree of displacement) when a card at a height H (m) is shifted at a velocity V (m / s) is the shear rate = V / H.

[0040] In this embodiment, of the multiple through holes 32 in the center post 30, only the first through hole 321 may be an inclined through hole, while the other through holes 32 may be inclined through holes or non-inclined through holes. In this embodiment, a "non-inclined through hole" is a through hole that is not inclined toward the upstream end and downstream end of the hollow cylindrical body. More specifically, a non-inclined through hole is a through hole that is provided approximately perpendicular to the axis of the hollow cylindrical body.

[0041] The polymer filter 1 is typically placed between a feeder that supplies molten polymer and a molding machine that has a mold for polymer molding. When the molten polymer is introduced from the feeder through the inlet 11 into the polymer filter 1, it flows downstream through the inlet channel 14. The polymer flowing through the inlet channel 14 then flows from the outer circumference to the inside of the disc-shaped filter 20 and is filtered. The polymer filtered by the disc-shaped filter 20 is discharged from the inner circumference of the disc-shaped filter 20. A center post 30 is inserted into the central through-hole 23 of the disc-shaped filter 20, and the outer wall of the center post 30 has a plurality of through-holes 32 as described above. Therefore, the polymer discharged from the disc-shaped filter 20 enters the inside of the center post 30 through each through-hole 32, moves downstream through the internal channel 33 of the center post 30, and is discharged to the outside through the opening (outlet 34) at the downstream end of the internal channel 33. The filtered polymer, derived from the polymer filter 1, is introduced, for example, into the mold of the molding machine to produce a polymer molded body.

[0042] (Extreme Variation 1-1) The external shape of the center post 30 is not particularly limited and may be, for example, a polygonal prism or a cylinder. In the case of a polygonal prism, it is not limited to a hexagonal prism as described above, but may be a triangular prism, a square prism, a pentagonal prism, a heptagonal prism, an octagonal prism, etc. The internal shape of the center post 30 may be a cylinder or a polygonal prism, and may be the same as the external shape or different. The internal shape of the center post 30 is preferably a cylinder, and may have a tapered region 331 as described above, so the diameter of the internal diameter may vary.

[0043] (Examples 1-2) This embodiment shows an example in which at least one first through-hole is an inclined through-hole, but is not limited thereto. For example, other through-holes besides the first through-hole may also be inclined through-holes.

[0044] (Embodiment 2) This embodiment shows an example in which the center post has two or more inclined through holes as the first through holes. Unless otherwise specified, the center post of this embodiment is the same as that of Embodiment 1, except for the number of inclined through holes, and the description of Embodiment 1 can be applied by reference.

[0045] The center post of this embodiment has two or more first through holes on the upstream side in the axial direction, and two or more of these first through holes are in the form of inclined through holes. In this way, since the center post of this embodiment has two or more inclined through holes as the first through holes, resin retention can be further suppressed.

[0046] Figure 7 shows an example of the center post 50 (also called the center pole) of this embodiment. Figure 7 is a partial cross-sectional view taken from the dotted line area of ​​Figure 3B, similar to Figure 5 of Embodiment 1.

[0047] The center post 50 has two first through-holes 321 located on the upstream side, each of which is an inclined through-hole. That is, the center post 50 has a hexagonal prism shape, similar to Figure 4B of Embodiment 1, and two opposing side walls 31a and 31d of the six side walls have first through-holes 321 (321a, 321d) which are inclined through-holes, at the same position in the axial direction (axisF). The inside of the two first through-holes 321 (321a, 321d) and the internal flow path 33 of the hollow cylindrical body (the tip of the tapered region 331) merge in the confluence region E of the dotted circle frame. Since the center post 50 of this embodiment has two inclined through-holes on the upstream side in the axial direction (axisF), resin stagnation can be further suppressed.

[0048] The inclination angles θa of the first through-hole 321a and θd of the first through-hole 321d are not particularly limited, and the examples in Embodiment 1 can be used by reference. The first through-hole 321a and the first through-hole 321d may have the same inclination angle or different inclination angles.

[0049] Furthermore, the positional relationship between the first through-hole 321a and the first through-hole 321d in the XY coordinate system can be expressed, for example, by an angle (θa + θd) defined by their respective axes. The lower limit of this angle is, for example, 60°, 90°, and 120°, the upper limit is, for example, 170°, 160°, and 150°, and the range is, for example, 60~170°, 60~160°, 60~150°, 90~170°, 90~160°, 90~150°, 120~170°, 120~160°, and 120~150°.

[0050] In this embodiment, a hexagonal prism-shaped center post 50 is illustrated in which opposing side walls 31a and 31d have first through holes 321a and 321d, but the embodiment is not limited thereto. When there are two of the first through holes, the combination of side walls 31 is not particularly limited, and may be a combination of adjacent side walls (e.g., 31a and 31b, 31b and 31c, 31c and 31d, 31e and 31f, 31f and 31a), or a combination of distant side walls (e.g., 31a and 31c, 31d, or 31e; 31b and 31d, 31e, or 31f; 31c and 31e or 31f; 31d and 31f), preferably a combination of side walls in an opposing positional relationship.

[0051] The two first through holes have an angle defined by their respective axes, with a lower limit of, for example, 60°, 90°, and 120°, an upper limit of, for example, 175°, 170°, and 150°, and a range of, for example, 60~170°, 60~160°, 60~150°, 90~170°, 90~160°, 90~150°, 120~170°, 120~160°, and 120~150°. The angle is, for example, the angle between the axis of one first through hole and the axis of the other first through hole, with the intersection of the axes of the two first through holes as the vertex.

[0052] (Variation 2-1) In the center post 50, there may be two or more through holes (first through holes) located on the upstream side, specifically three, four, five, or six. Furthermore, two or more of the multiple first through holes may be inclined through holes, or all of them may be inclined through holes. In this embodiment, since it is an example of a center post of a hexagonal prism, the number of first through holes is exemplified as 2 to 6, but the present invention is not limited thereto.

[0053] As a specific example, consider a configuration having three first through-holes located on the upstream side. In this case, in the hexagonal prism-shaped center post 50, the non-adjacent side walls 31a, 31c, and 31e each have a first through-hole 321 at the same position in the axial direction (axisF), and two or all of the three first through-holes may be inclined through-holes.

[0054] If all three first through holes 321 are inclined through holes, the inclination angle θ of each is 0° or more and less than 90°, and the lower limit, upper limit, and range can be drawn from the examples in Embodiment 1, for example. Specifically, for example, it is greater than 0° and less than 90°, and 50 to 55° is preferred. The three first through holes 321a may have the same inclination angle or different inclination angles.

[0055] Of the three first through holes 321, two adjacent first through holes 321 have a lower limit of the angle defined by their respective axes, for example, 60, 70, and 80°, an upper limit, for example, 115°, 100°, and 110°, and a range, for example, 60~115°, 70~110°, and 80~110°. The angle between the adjacent first through holes 321 is, for example, the angle between the axis of one first through hole 321 and the axis of the other first through hole 321, with the intersection of the axes of the three first through holes 321 as the vertex.

[0056] Another specific example is a configuration having six through-holes (first through-holes) located on the upstream side. In this case, in the hexagonal prism-shaped center post 50, all six side walls 31a, 31c, and 31e each have a first through-hole 321 at the same position in the axial direction, and two, two or more, or all of the six first through-holes may be inclined through-holes.

[0057] If all six first through-holes 321 are inclined through-holes, the inclination angle θ of each is 0° or more and less than 90°, and the lower limit, upper limit, and range can be drawn from the examples in Embodiment 1, for example. Specific examples include, for example, a range of 50 to 60°, which is greater than 0° and less than 90°. The six first through-holes 321a may have the same inclination angle or different inclination angles.

[0058] Of the six first through holes 321, two adjacent first through holes 321 have a lower limit of the angle defined by their respective axes, for example, 25°, 30°, and 35°, an upper limit, for example, 50°, 54°, and 58°, and a range, for example, 25~58°, 30~54°, and 35~50°. The angle between the adjacent first through holes 321 is, for example, the angle between the axis of one first through hole 321 and the axis of the other first through hole 321, with the intersection of the axes of the six first through holes 321 as the vertex.

[0059] (Embodiment 3) The center post of the above embodiments 1 and 2 may have the following conditions, for example.

[0060] (Intermediate section 302) External shape: Regular hexagonal prism Length: 20-1500mm, 100-600mm Number of through-holes 32 per side wall 31: 2-45, 10-20 (Through hole 32) Internal shape: Cylinder Diameter D: 15~90mm, 20~45mm Number of first through-holes 321: 1-6, 2-12 Number of inclined first through holes 321: 1-6, 2-12 Inclination angle θ of inclined through hole 321: 10~89°, 30~85° (Internal flow path 33) Diameter D of the upstream tip of the tapered region 331: 5-20mm, 6-15mm Diameter D at the downstream rear end of the tapered region 331 (diameter D of the non-tapered region): 15-90 mm, 20-45 mm Tapered section 331 length: 12-500mm, 35-200mm Length of non-tapered area: 8-1000mm, 50-500mm

[0061] [Center post for polymer filters] As described above, the center post for polymer filters of the present invention is It is a hollow cylindrical body, In the axial direction, the upstream end is closed. The side wall has multiple through holes, and these multiple through holes are polymer inlets. In the axial direction, the downstream end is open, and this opening is the outlet for the polymer. In the aforementioned side wall, the through-hole located on the upstream side is an inclined through-hole. The inclined through-hole is inclined toward the upstream end of the hollow cylindrical body, and the inclination angle defined by the axis of the inclined through-hole and the axis of the hollow cylindrical body is 0° or more and less than 90°. This invention is characterized by being used in the polymer filter described above.

[0062] The center post for polymer filters of the present invention can be adapted from the description of the center post described in the polymer filter of the present invention.

[0063] [Method for manufacturing polymer molded articles] The method for producing a polymer molded article of the present invention is: A step of filtering a molten polymer using the polymer filter of the present invention, and The method is characterized by including a step of molding the molten polymer after filtration.

[0064] The manufacturing method of the present invention is characterized by filtering the molten polymer using a polymer filter equipped with the center post of the present invention, and using the filtered molten polymer as a molding material, with no other steps or conditions being particularly limited. The manufacturing method of the present invention can be adapted from the description of the polymer filter of the present invention. The polymer molded article is also called, for example, a polymer processed article.

[0065] The type of polymer to be treated with the polymer filter of the present invention is not particularly limited, and any polymer used as a raw material for polymer molding can be used. Examples of such polymers include PP, PE, EVA, PVA, PMMA, PS, PC, PET, PA, COP, COC, PBT, PEN, LCP, PEEK, and the like. [Examples]

[0066] [Example 1] A 3D model of the internal flow path of a center post having a single inclined first through-hole was created, and the improvement in resin retention was confirmed by shear rate through computer simulation.

[0067] The internal flow path model of the center post is a model of the upstream portion of the internal flow path, that is, it is a model of the first through-hole, the tapered region, and a portion of the internal flow path downstream thereof.

[0068] The first embodiment model is an internal flow path model 30M for the center post 30 shown in Figure 4A of the first embodiment, and Figure 8 shows a schematic diagram of a partial region of the internal flow path. Specifically, Figure 8 shows the shape of the partial region in the XY plane as viewed from the Z axis in the XYZ coordinate system. The partial region has a flow path 53 corresponding to the upstream region of the internal flow path and an inclined cylindrical first through hole 521, and the two are in communication. The flow path 53 has a cylindrical region on the downstream side and a tapered region 531 on the upstream side. Eight types of the first embodiment model 30M were manufactured, and the inclination angle θ defined by the axis (axis H) of the first through hole 521 and the axis (axis F) of the flow path 53 was set to 85°, 80°, 75°, 60°, 55°, 50°, 45°, or 30° for each. In Figure 8, the axial direction of the flow path 53 is shown as the X-axis, and each position in the X coordinate system is shown as a length (X) starting from the downstream end of the flow path 53 (coordinate X0, X=0mm). To the right of Figure 8, a schematic diagram of the positional relationship of the first through-hole 521 in the YZ coordinate system is shown. As shown to the right of Figure 8, the position passing through the opening end E521 of the first through-hole 521 and the axis (axis F) of the flow path 53 is set as coordinate Z=0.

[0069] Comparative Example 1 Model is an internal flow path model 40M for the conventional center post 40 shown in Figure 6 above, and Figures 9A and 9B show schematic diagrams of a partial region of the internal flow path. Specifically, Figures 9A and 9B show the shape of the partial region in the XY plane as viewed from the Z axis in the XYZ coordinate system. The partial region has a flow path 53 (the same as the Model 30M of Example 1) corresponding to the upstream region of the internal flow path, and a non-inclined cylindrical first through hole 621, and the two are in communication with each other. In Comparative Example 1 Model 40M, the angle θ defined by the axis (axisH) of the first through hole 621 and the axis (axisF) of the flow path 53 is set to 90°. The first through hole 621 of Comparative Example 1 Model 40M is called a non-inclined through hole (also called a right-angle through hole). In Figures 9A and 9B, the axial direction of the flow path 53 is shown as the X-axis, and each position in the X coordinate is shown as a length (X) starting from the downstream end of the flow path 53 (coordinate X0, X=0mm), similar to the Model 30M of Example 1. To the right of Figure 9A is a schematic representation of the positional relationship of the first through-hole 621 in the YZ coordinate system. As shown to the right of Figure 9A, the position passing through the opening end E621 of the first through-hole 621 and the axis (axisF) of the flow path 53 is set to coordinate Z=0.

[0070] Figure 9B shows the coordinates of each position in Comparative Example 1 Model 40M. In Figure 9B, length X is the length in the X-axis direction, and is the length of each position starting from the downstream end of the flow path 53 (coordinate X0, X=0mm), and length Y is the length in the Y-axis direction, and is the length of each position starting from the center point of the downstream end (Outlet) of the flow path 53 (coordinate Y0, Y=0mm).

[0071] Comparison Example 1: Conditions for Model 40M (Flow channel 53) Length from X0 to X1: 20mm Length from X0 to X2: 122.9mm Length from X1 to X2 (length of tapered region 531): 102.9 mm X0 diameter (Outlet diameter): φ30mm X2 diameter: φ12mm (First through-hole 621) Diameter: φ12mm Length from Y0 to Yc: 47mm (merging area E) The region from coordinate X2 to coordinate X3c

[0072] The structure of Example 1 Model 30M is the same as that of Comparative Example 1 Model 40M in terms of X0 to X2, except that the angle θ between the axis of the first through hole 521 (axisH) and the axis of the flow path 53 (axisF) is different.

[0073] For Example 1 Model 30M and Comparative Example 1 Model 40M, the shear rate in the first through-holes (521, 621) and flow path 53 of each model was analyzed by simulation, assuming that resin was poured in from the first through-holes (521, 621). Specifically, the following method was used. That is, Example 1 Model 30M and Comparative Example 1 Model 40M were loaded as 3D analysis models into fluid simulation software (product name ANSYS FLUENT, ANSYS Corporation), and the condition of pouring 250°C polypropylene resin at a flow rate of 0.001 kg / s into the inlet of the first through-hole was given, and a steady flow analysis was performed. Then, from the analysis data, the shear rate data of the flow path wall surface at Z=0mm was extracted, and the relationship between the shear rate and the X coordinate or Y coordinate was plotted on a graph.

[0074] These results are shown in Figure 10. Figure 10 is a graph showing the shear rate distribution at the X coordinate (Z=0), where the vertical axis represents the shear rate (sec). -1 The horizontal axis is the X coordinate (mm). Specifically, Figure 10 is a graph showing the shear rate in the region indicated by the arrow in the XY plane of Figure 11 for Example 1 Model 30M and Comparative Example 1 Model 40M.

[0075] As shown in Figure 10, in the case of Comparative Example 1 Model 40M, where the first through-hole 621 is positioned perpendicular to the axis (axis F) of the flow path 53, the minimum shear rate in the confluence region E (X coordinates 128-135) is 1.2 sec. -1This showed a low value. In contrast, in the case of Example 1 Model 30M, the shear rate improved as the inclination angle θ of the first through-hole 521 with respect to the axis (axisF) of the flow path 53 was reduced. In particular, Example 1 Model 30M was able to achieve a significantly higher shear rate than Comparative Example 1 Model 40M by setting the inclination angle θ to 60° or less. Although not shown, for Example 1 Model 30M in Figure 8 and Comparative Example 1 Model 40M in Figure 9A, a gradient from red to blue (5 sec) corresponds to the shear rate. -1 The above are in red, minimum 0 sec. -1 A contour plot was created, represented in blue. According to the contour plot, the confluence region E of Comparative Example 1 Model 40M showed a blue color in the outer curved portion e, indicating an extremely low shear rate, while the confluence region E of Example 1 Model 30M showed a color closer to red than that of Comparative Example 1 Model 40M.

[0076] Thus, according to the embodiment model in which the first through-hole is an inclined through-hole, the shear rate can be improved compared to the comparative example model, which improves the shear stress and, as a result, makes it possible to effectively prevent resin buildup.

[0077] [Example 2] A simulation was conducted on an internal flow path model of a center post having two inclined first through-holes, and the improvement in resin retention was confirmed by shear rate. Unless otherwise specified, the above-described embodiment 1 can be used.

[0078] The internal flow path model of Example 2 is the same as that of Example 1, except that the one first through-hole 521 in the internal flow path model of Example 1 is changed to two. Figure 12A shows a schematic of the internal flow path model 50M of Example 2. Figure 12A is an XY coordinate diagram and shows the shape of the partial region in the XY plane as viewed from the Z axis. The partial region has a flow path 53 corresponding to the upstream region of the internal flow path and two inclined cylindrical first through-holes 521 (521a, 521d), and the two are in communication with each other. The inclination angle θa defined by the axis (axisH) of one first through-hole 521a and the axis (axisF) of the flow path 53 and the inclination angle θd defined by the axis (axisH) of the other first through-hole 521d and the axis (axisF) of the flow path 53 are the same. In Example 2, Model 50M was fabricated in eight variations, each with an inclination angle θ(θa, θd) set to 85°, 80°, 75°, 60°, 55°, 50°, 45°, or 30°. The right side of Figure 12A shows a schematic representation of the positional relationship between the first through-holes 521a and 521d in YZ coordinates. As shown on the right side of Figure 12A, the opening end E521a of the first through-hole 521a and the opening end E521d of the first through-hole 521d were arranged symmetrically across the axis (axisF) of the flow path 53. The position passing through the opening end E521a of the first through-hole 521a and the axis (axisF) of the flow path 53 was defined as coordinate Z=0.

[0079] The internal flow path model of Comparative Example 2 is the same as that of Comparative Example 1, except that one first through hole 621 in the internal flow path model of Comparative Example 1 is changed to two. FIG. 12B shows an outline of the internal flow path model 60M of Comparative Example 2. FIG. 12B is a diagram of XY coordinates and shows the shape of the partial region in the XY plane as viewed from the Z axis. The partial region has a flow path 53 corresponding to the upstream region of the internal flow path and two non-inclined cylindrical first through holes 621 (621a, 621d), and the two are in a communicating form. In the Comparative Example 2 model 60M, the angle θ defined by the axis (axisH) of the first through hole 621 (621a, 521d) and the axis (axisF) of the flow path 53 is set to 90°. The axes (axisH) of the first through holes 621a and 621d are set on the same XY plane (coordinate 0 of the Z axis). On the right side of FIG. 12B, a schematic of the positional relationship between the first through holes 621a and 621d in the YZ coordinates is shown. As shown on the right side of FIG. 12B, the opening end E621a of the first through hole 621a and the opening end E621d of the first through hole 621d are symmetrically arranged via the axis (axisF) of the flow path 53. The position passing through the opening end E621a of the first through hole 621a and the axis (axisF) of the flow path 53 is set as the coordinate Z = 0.

[0080] For each of the Example 2 model 50M and the Comparative Example 2 model 60M, assuming that resin is simultaneously poured from the two first through holes (521a and 521d, or 621a and 621d) under the same conditions, the shear rates in the first through holes (521, 621) and the flow path 53 of each model were analyzed by simulation. The analysis method was the same as that of Example 1.

[0081] These results are shown in FIG. 13. FIG. 13 is a graph showing the shear rate distribution at the Y coordinate (Z = 0). The vertical axis is the shear rate (sec -1 ), and the horizontal axis is the Y coordinate (mm). Specifically, FIG. 13 is a graph showing the shear rates in the regions indicated by the arrows in the XY plane of FIG. 14 for the Example 2 model 50M and the Comparative Example 2 model 60M.

[0082] As shown in Figure 13, in the case of Comparative Example 2 Model 60M, where the first through-hole 621 is positioned perpendicular to the axis (axisF) of the flow path 53, the minimum shear rate in the confluence region E (Y coordinate ±0.5) is 0.66 sec. -1 This showed a low value. In contrast, in the case of Example 2 Model 50M, the shear rate improved as the inclination angle θ of the first through-hole 521 (521a, 521d) decreased. In particular, Example 2 Model 50M was able to achieve a significantly higher shear rate than Comparative Example 2 Model 60M by setting the inclination angle θ to 50° or less. Although not shown in the figures, contour plots were created for Example 1 Model 50M and Comparative Example 2 Model 60M. The confluence region E of Comparative Example 2 Model 60M showed a blue color indicating an extremely low shear rate around Y coordinate ±0.5, while the confluence region E of Example 2 Model 50M showed a color closer to red than Comparative Example 2 Model 60M around Y coordinate ±0.5.

[0083] Thus, according to the embodiment model in which the two first through holes are inclined through holes, the shear rate can be improved compared to the comparative example model, which improves the shear stress and, as a result, makes it possible to effectively prevent resin buildup.

[0084] [Example 3] A simulation was conducted on an internal flow path model of a center post having three inclined first through-holes, and the improvement in resin retention was confirmed by shear rate. Unless otherwise specified, the above-described embodiment 1 can be used.

[0085] The internal flow path model of Example 3 is the same as that of Example 1, except that the one first through-hole 521 in the internal flow path model of Example 1 has been changed to three. That is, the Example 3 model has a flow path corresponding to the upstream region of the internal flow path and three inclined cylindrical first through-holes (521a, 521c, 521e, not shown), and the two are in communication with each other. The inclination angle θ of the three first through-holes is set to be the same, that is, the inclination angle θ defined by the axis of the first through-hole (axis H) and the axis of the flow path (axis F). Eight types of Example 3 models were manufactured, and the inclination angle θ of the three first through-holes was set to 85°, 80°, 75°, 60°, 55°, 50°, 45°, or 30° for each. Figure 15 shows a schematic of the positional relationship of the three first through-holes in YZ coordinates. In Figure 15, the left figure is a schematic of the model of Example 3. As shown in Figure 15, the three first through-holes 521a, 521c, and 521e are arranged such that the opening ends E521a, E521c, and E521e of adjacent first through-holes are evenly spaced at 120° across the axis (axis F) of the flow path 53. The position passing through the opening end E521a of the first through-hole 521a and the axis (axis F) of the flow path 53 is defined as coordinate Z=0.

[0086] Comparative Example 3 is the same as Comparative Example 1, except that the one first through-hole 621 in the internal flow path model of Comparative Example 1 is changed to three. The three first through-holes (621a, 621c, 621e, not shown) each have the same inclination angle θ, that is, the inclination angle θ defined by the axis of the first through-hole (axisH) and the axis of the flow path (axisF), which is 90°. In Figure 15 mentioned above, the right figure is a schematic of the model of Comparative Example 3. As shown in Figure 15, the three first through-holes 621a, 621c, and 621e are arranged such that the opening ends E621a, E621c, and E621d of adjacent first through-holes are evenly 120° through the axis of the flow path 53 (axisF). The position passing through the opening end E621a of the first through-hole 621a and the axis of the flow path 53 (axisF) is set to coordinate Z=0.

[0087] For each of the three models in Example 3 and Comparative Example 3, the shear rate in the first through-holes (521, 621) and the flow path 53 was analyzed by simulation, assuming that resin was simultaneously poured through the three first through-holes (521a, 521c, and 521e, and 621a, 621c, and 621e) under the same conditions. The analysis method was the same as in Example 1.

[0088] These results are shown in Figure 16. Figure 16 is a graph showing the shear rate distribution at the Y coordinate (Z=0), with the vertical axis representing the shear rate (sec). -1 The horizontal axis is the Y-coordinate (mm).

[0089] As shown in Figure 16, in the case of Comparative Example 3 model, where the first through-hole 621 is positioned perpendicular to the axis (axisF) of the flow path 53, the minimum shear rate in the confluence region E (Y coordinate ±0.5) is 0.47 sec. -1 This showed a low value. In contrast, in the case of the Example 3 model, the shear rate improved as the inclination angle θ of the first through-hole 521 (521a, 521c, 521e) decreased. In particular, the Example 3 model achieved a significantly higher shear rate than the Comparative Example 3 model by setting the inclination angle θ to 55° or less. Although not shown in the figures, contour plots were created for the Example 1 model and the Comparative Example 2 model. The confluence region E of the Comparative Example 3 model showed a blue color indicating an extremely low shear rate around the Y coordinate ±0.5, while the confluence region E of the Example 3 model showed a color closer to red than that of the Comparative Example 3 model around the Y coordinate ±0.5.

[0090] Thus, according to the embodiment model in which the three first through holes are inclined through holes, the shear rate was improved compared to the comparative example model, which improved the shear stress and, as a result, made it possible to effectively prevent resin buildup.

[0091] [Example 4] A simulation was conducted on an internal flow path model of a center post having six inclined first through-holes, and the improvement in resin retention was confirmed by shear rate. Unless otherwise specified, the above-described embodiment 1 can be used.

[0092] The internal flow path model of Example 6 is the same as that of Example 1, except that the one first through-hole 521 in the internal flow path model of Example 1 is changed to six. That is, the Example 3 model has a flow path corresponding to the upstream region of the internal flow path and six inclined cylindrical first through-holes (521a, 521b, 521c, 521d, 521e, 521f, not shown), and the two are in communication. The inclination angle θ of the six first through-holes is the same, that is, the inclination angle θ defined by the axis of the first through-hole (axis H) and the axis of the flow path (axis F). Eight types of Example 4 models were manufactured, and the inclination angle θ of the six first through-holes was set to 85°, 75°, 60°, 45°, or 30° for each. Figure 17 shows a schematic of the positional relationship of the six first through-holes in YZ coordinates. In Figure 17, the left figure is a schematic of the model of Example 4. As shown in Figure 17, the six first through-holes 521a, 521b, 521c, 521d, 521e, and 521f are arranged such that the opening ends E521a, E521b, E521c, E521d, E521e, and E521f of adjacent first through-holes are evenly spaced at 60° angles across the axis (axis F) of the flow path 53. The position passing through the opening end E521a of the first through-hole 521a and the axis (axis F) of the flow path 53 is defined as coordinate Z=0.

[0093] Comparative Example 4 is the same as Comparative Example 1, except that the one first through-hole 621 in the internal flow path model of Comparative Example 1 is changed to six. The six first through-holes (621a, 621b, 621c, 621d, 621e, 621f) each have the same inclination angle θ, that is, the inclination angle θ defined by the axis of the first through-hole (axis H) and the axis of the flow path (axis F), which is 90°. In Figure 17 above, the right figure shows a schematic of the model of Comparative Example 4. As shown in Figure 17, the six first through-holes 621a, 621b, 621c, 621d, 621e, 621f are arranged such that the opening ends E621a, E621b, E621c, E621d, E621e, E621f of adjacent first through-holes are evenly 60° across the axis (axis F) of the flow path 53. The position where the opening end E621a of the first through-hole 621a passes through the axis (axis F) of the flow path 53 was defined as coordinate Z=0.

[0094] For each of the four example models and the four comparative example models, the shear rate in the first through-holes (521, 621) and the flow path 53 of each model was analyzed by simulation, assuming that resin was simultaneously poured through the six first through-holes (521a-521f, 621a-621f) under the same conditions. The analysis method was the same as in Example 1.

[0095] These results are shown in Figure 18. Figure 18 is a graph showing the shear rate distribution at the Y coordinate (Z=0), with the vertical axis representing the shear rate (sec). -1 The horizontal axis is the Y-coordinate (mm).

[0096] As shown in Figure 18, in the case of Comparative Example 4 model, where the first through-hole 621 is positioned perpendicular to the axis (axisF) of the flow path 53, the minimum shear rate in the confluence region E (Y coordinate ±0.5) is 0.99 sec. -1This showed a low value. In contrast, in the case of the 3rd example model, the shear rate improved as the inclination angle θ of the six first through holes 521 was reduced. In particular, the 4th example model achieved a significantly higher shear rate than the 4th comparative example model by setting the inclination angle θ to 60° or less. Although not shown in the figures, contour plots were created for the 4th example model and the 4th comparative example model. The confluence region E of the 4th comparative example model showed a blue color indicating an extremely low shear rate around Y coordinate ±0.5, while the confluence region E of the 4th example model showed a color closer to red than that of the 4th comparative example model around Y coordinate ±0.5.

[0097] Thus, according to the embodiment model in which the six first through holes are inclined through holes, the shear rate was improved compared to the comparative example model, which improved the shear stress and, as a result, made it possible to effectively prevent resin buildup.

[0098] [Example 5] We fabricated an internal channel made of resin and confirmed fluid retention.

[0099] The resin model for Example 5 had the same shape as the internal flow path model for Example 2 shown in Figure 12A. Similarly, the resin model for Comparative Example 5 had the same shape as the internal flow path model for Comparative Example 2 shown in Figure 12B. Acrylic resin was used and manufactured by machining. Figure 19 shows photographs and schematic diagrams of the resin models. In Figure 19, the upper row shows the resin models for the Examples, and the lower row shows the resin models for the Comparative Examples. The conditions for each resin model are shown below.

[0100] (Resin model of Example 5) Taper region 531 of flow path 53 Length: 76mm Inner diameter of one end X1 of tapered region 531: 30 mm diameter Inner diameter of X2 at the other end of tapered region 531: 10 mm diameter First through hole 521a Length (length from the intersection of axisF and axisH to the end of axisH): 47.9 mm Inner diameter: 10mm Angle θa between axis F of the tapered region 531 and axis H of the first through hole 521a: 60° 1st through hole 521d Length (length from the intersection of axisF and axisH to the end of axisH): 47.9 mm Inner diameter: 10mm The angle θd between the axis F of the tapered region 531 and the axis H of the first through hole 521a is 60°. In the schematic diagram of the resin model of the example shown in Figure 19, the length in the direction of the arrow is 45 mm.

[0101] (Comparative Example 5: Resin Model) Taper region 531 of flow path 53 Length: 76mm Inner diameter of one end X1 of tapered region 531: 30 mm diameter Inner diameter of X2 at the other end of tapered region 531: 10 mm diameter First through hole 621a Length (length from the intersection of axisF and axisH to the end of axisH): 50mm Inner diameter: 10mm Angle θa between axisF of the tapered region 531 and axisH of the first through hole 621a: 90° 1st through hole 621d Length (length from the intersection of axisF and axisH to the end of axisH): 50 mm Inner diameter: 10mm The angle θd between axisF of the tapered region 531 and axisH of the first through hole 621a is 90°. In the schematic diagram of the comparative example resin model in Figure 19, the length in the direction of the arrow is 45 mm.

[0102] The fluid was prepared by dissolving CMC (carboxymethylcellulose sodium, CAS 9004-32-4, Hayashi Pure Chemical Industries) in tap water to create a 2 wt% CMC aqueous solution (viscosity 2000 mPa·s, shear rate 5 sec). -1Then, red and white poster paints (manufactured by Sakura Color Products) were added to prepare red and white CMC aqueous solutions, respectively, to a final concentration of 0.2-0.3%.

[0103] Under condition 1, the resin model was pre-filled with the white CMC aqueous solution, and then the red CMC aqueous solution was introduced (white to red substitution). Under condition 2, the resin model was pre-filled with the red CMC aqueous solution, and then the white CMC aqueous solution was introduced (red to white substitution). A liquid delivery device (small chemical-resistant gear pump GPU-1, AS ONE Corporation) was used for introduction, and the flow rate was set to 1.8 kg / h for each of the two through-holes, for a total of 3.6 kg / h.

[0104] For condition 1, the retention of each CMC aqueous solution in the curved region E was confirmed from the start of introduction of the red CMC aqueous solution. If condition 1 is met, suppressing retention will result in a smoother exchange from the white CMC aqueous solution to the red CMC aqueous solution. For condition 2, the retention of each CMC aqueous solution in the curved region E was confirmed from the start of introduction of the white CMC aqueous solution. If condition 2 is met, suppressing retention will result in a smoother exchange from the red CMC aqueous solution to the white CMC aqueous solution.

[0105] These results are shown in Figures 20 and 21. Figures 20A and 20B are photographs showing the introduction of the red CMC aqueous solution under condition 1 (substitution from white to red), with Figure 20A showing the results for the example resin model and Figure 20B showing the results for the comparative example resin model. Figures 21A and 21B are photographs showing the introduction of the white CMC aqueous solution under condition 2 (substitution from red to white), with Figure 21A showing the results for the example resin model and Figure 21B showing the results for the comparative example resin model. In these figures, the arrows indicate the direction of discharge of the CMC aqueous solution.

[0106] As shown in Figures 20B and 21B, the comparative example had the following problem: at the confluence of the two holes (first through-holes 621a and 621d) through which the fluid flows, the color change from white to red, or from red to white, took a long time. In contrast, as shown in Figures 20A and 21A, in the embodiment, the color change from white to red, or from red to white, at the confluence of the two holes (first through-holes 521a and 521d) through which the fluid flows was smooth. Furthermore, in the 120-second results in Figures 20A and 20B, in which the red CMC aqueous solution was introduced, the resin model of the embodiment showed a stronger reddish tint to the solution at the outlet end of the flow path, and the entire flow path also showed a stronger reddish tint to the solution, compared to the resin model of the comparative example. In the 120-second results shown in Figures 21A and 21B, in which a white CMC aqueous solution was introduced, the resin model of the embodiment showed a stronger whiteness of the solution at the outlet end of the flow path and also a stronger whiteness of the solution throughout the entire flow path, compared to the resin model of the comparative example.

[0107] Furthermore, Figure 22 shows, as an example, an enlarged view of the area around the curved region E of the 60-second result under condition 1 (substitution from white to red). In Figure 22, the left figure is an enlarged view of Example 5 (60 seconds) in Figure 20A, and the right figure is an enlarged view of Comparative Example 5 (60 seconds) in Figure 20B. As shown in Figure 22, in the enlarged view of the comparative example, a strong whiteness was observed in the curved region E, as indicated by the dotted line frame. This means that during the substitution from the white CMC aqueous solution to the red CMC aqueous solution, the white CMC aqueous solution remained in the curved region E, hindering the rapid substitution to the red CMC aqueous solution. In contrast, in the enlarged view of the example, the strong whiteness seen in the comparative example was not observed in the curved region E, indicating that a rapid substitution to the red CMC aqueous solution occurred. The same was confirmed for condition 2.

[0108] From these results, it was found that, compared to the comparative example's resin model, the resin model of the example suppressed stagnation at the confluence point, allowing for smoother liquid introduction and rapid replacement of the solution throughout the entire flow path.

[0109] Although the present invention has been described above with reference to the embodiments and examples, the present invention is not limited to the above embodiments and examples. Various modifications to the structure and details of the present invention can be made within the scope of the present invention as can be understood by those skilled in the art.

[0110] This application claims priority based on Japanese Patent Application No. 2024-202439, filed on November 20, 2024, and incorporates all of its disclosures herein. [Industrial applicability]

[0111] According to the polymer filter of the present invention, the degradation of the polymer can be suppressed by reducing the retention of the polymer. [Explanation of Symbols]

[0112] 1. Polymer filter 10 containers 101 Container body 102 Container base 11 Inlet 14 Inlet channel 13 Containment Space 20 disk-type filters 21 Filtration element 21 22 Spacers 23 Through hole 211 holes 30, 40, 50 Centerpost 301 Downstream 302 Middle section 303 Upstream 31 Side wall 32 Through holes 321, 521, 621 First through hole 421 Through hole 33 Internal flow path 331, 531 Taper area 34 Opening 53 channels

Claims

1. It includes the container body, a disc-shaped filter, and a center post; The container body is It has a polymer inlet, an inlet channel communicating with the inlet, and a containment space communicating with the inlet channel. The disk-type filter and the center post are housed in the aforementioned housing space; The aforementioned disk-type filter is It has a through hole in the center, With the center post inserted into the through hole, the container is housed in the storage space of the container body; The aforementioned center post is, It is a hollow cylindrical body, In the axial direction, the upstream end is closed. The side wall facing the disk filter has a plurality of through holes, and these plurality of through holes are polymer inlets. In the axial direction, the downstream end is open, and this opening is the outlet for the polymer. In the aforementioned side wall, the through-hole located on the upstream side is an inclined through-hole. The inclined through-hole is inclined toward the upstream end of the hollow cylinder, and the inclination angle defined by the axis of the inclined through-hole and the axis of the hollow cylinder is 0° or more and less than 90°. A polymer filter characterized by the following features.

2. The polymer filter according to claim 1, wherein the inclination angle of the inclined through-hole in the center post is 30 to 85°.

3. The polymer filter according to claim 1 or 2, wherein the number of inclined through holes located on the most upstream side of the center post is 2 to 20.

4. The polymer filter according to claim 1 or 2, wherein the center post has 2 to 20 through holes from the upstream side, which are inclined through holes that are inclined toward the upstream end of the hollow cylindrical body.

5. In the aforementioned center post, The inclined through-holes are two or more, The polymer filter according to claim 1 or 2, wherein the hollow upstream end of the hollow cylindrical body is the confluence region of the inclined through-holes.

6. In the aforementioned center post, The inclined through-holes are two or more, The polymer filter according to claim 1 or 2, wherein the angle defined by the relative axes of the inclined through holes is 25 to 170°.

7. In the aforementioned center post, The inclined through-holes are two or more, The polymer filter according to claim 1 or 2, wherein the angle defined by the mutual axes of the two inclined through holes that are opposite each other around the axis of the hollow cylindrical body is 25 to 170°.

8. In the aforementioned center post, The inclined through-holes are two or more, The polymer filter according to claim 1 or 2, wherein the hollow upstream end of the hollow cylindrical body is the confluence region of the inclined through-holes.

9. In the aforementioned center post, The inclined through-holes are two or more, The polymer filter according to claim 8, wherein adjacent inclined through holes are in contact at their respective ends on the confluence region side.

10. In the aforementioned center post, The inclined through-holes are two or more, The polymer filter according to claim 1 or 2, wherein the angle defined by the mutual axes of the two inclined through holes that are opposite each other around the axis of the hollow cylindrical body is 25 to 170°.

11. The hollow of the aforementioned hollow cylindrical body is cylindrical, The polymer filter according to claim 1 or 2, wherein the hollow inside the through-hole is cylindrical.

12. It is a hollow cylindrical body, In the axial direction, the upstream end is closed. The side wall has multiple through holes, and these multiple through holes are polymer inlets. In the axial direction, the downstream end is open, and this opening is the outlet for the polymer. In the aforementioned side wall, the through-hole located on the upstream side is an inclined through-hole. The inclined through-hole is inclined toward the upstream end of the hollow cylindrical body, and the inclination angle defined by the axis of the inclined through-hole and the axis of the hollow cylindrical body is 0° or more and less than 90°. For use in the polymer filter according to claim 1 or 2 A center post for polymer filters characterized by the following features.

13. A step of filtering a molten polymer using the polymer filter described in claim 1 or 2, and This includes a step of molding the molten polymer after filtration. A method for producing a polymer molded article, characterized by the above.

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