JP4423186B2 - High viscosity fluid filter unit and spinning pack - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high viscosity fluid filter unit and a spin pack. It is suitable for filtration and separation of impurities and gels contained in highly viscous molten organic polymer compounds and polymer solutions.
[0002]
[Prior art]
Filter units manufactured for the purpose of filtering and separating and removing solid foreign substances in fluids are widely used in various industrial fields such as the electronics industry, precision industry, pharmaceutical industry, and water treatment, and their technical level. Is extremely sophisticated and easy to use. However, the filtration target has been developed mainly for low-viscosity substances such as air and water.
[0003]
On the other hand, filter units are used to filter and separate solid foreign substances in high-viscosity fluids in the plastic molding processing industry using organic polymer compounds as raw materials and in some food and agricultural fields. For example, synthetic fibers, synthetic films, and other organic polymer compound molded products are manufactured through processes such as spinning, film formation, and molding. In these processes, the raw material polymer is heated and melted or used as a solvent. It is dissolved and liquefied, and foreign substances and gelled substances are filtered and separated by a filtration device equipped with a filter unit or a spinning pack. These filtration operations, unlike the above-described filtration operations of air and water, are very inefficient because the organic polymer compound as a raw material and the solution thereof have a very high viscosity. Therefore, in order to increase the filtration speed, efforts have been made such as applying a filtration pressure several tens of times or hundreds of times higher than that of the low-viscosity material, or increasing the filtration area of the filter as much as possible. Until now, it has not achieved sufficient results.
[0004]
[Problems to be solved by the invention]
As a means for increasing the filtration area of the filter, for example, Japanese Patent Application Laid-Open No. 60-058208 discloses a filter unit in which a filtration membrane is reinforced with a net support, folded together, and formed into a pleated shape into a cylindrical shape. It is disclosed. This method is suitable for filtration of gas with low filtration pressure or liquid with low viscosity, but because it is cylindrical, there is a limit in terms of pressure resistance design etc. to filter high viscosity fluids that require high filtration pressure. . In addition, if a pleated filter is used in a case that requires a high filtration pressure, leakage from the filter periphery becomes a problem. Means for solving this problem is disclosed in Japanese Patent Application Laid-Open No. 10-211411. However, since an adhesive is used, it is unsuitable in terms of heat resistance to filter a high temperature molten polymer. Japanese Patent Application Laid-Open No. 2002-266152 discloses a filter unit for a melt spinning pack in which a metal wire filter and a metal wire non-woven fabric are overlapped to form a corrugated shape and the outer peripheral portion is sandwiched between metal rims. However, problems remain in measures against deformation of the filter part and prevention of leakage of the filtrate with respect to the filtration of viscoelastic fluid with high pressure loss.
[0005]
In the filtration process of the high temperature molten polymer, although it varies depending on the raw materials and operating conditions, it is not rare that a filtration pressure of about 10 to 30 MPa is required to efficiently filter a highly viscous fluid. In order to lower the filtration pressure, attempts have been made to increase the filtration area per spin pack, for example, by modifying the filter shape.
[0006]
However, the highly viscous fluid of the soot to be filtered leaks out from the filter periphery, bypassing the filter, causing product quality degradation and operational troubles, and the filtration pressure increases with the passage of time and the filter is deformed. However, the problem that the required filtration area cannot be maintained has occurred.
[0007]
The present invention prevents high-viscosity fluid to be filtered from leaking out by bypassing the filter when performing high-pressure filtration of high-viscosity fluid in a spinning process of synthetic fibers, a film-forming process of synthetic film, and the like. As a result of research and trial production on the subject of a highly reliable high-viscosity fluid filter unit that prevents the shape of the filter from being deformed by the filter and that can be stably and stably filtered for a long period of time. It is a collection.
[0008]
[Means for Solving the Problems]
The present invention will be described with reference to FIGS. 1 and 2. FIG. The present invention is a pleated plate-like body 3 composed of a plurality of layers folded in a zigzag manner by superposing a support member 2 on a sheet-like filter 1, and the peripheral edge 4 of the plate-like body is formed into a flat brim shape, Further, at least one surface of the collar-like portion 4 is overlapped with a ring sheet 5 made of a soft metal or a metal nonwoven fabric or a metal O-ring , and further covered with a thin metal plate 6, and the filter and support laminated on the collar-like portion 4. By crimping a member, a ring sheet or a metal O-ring, and a covered metal thin plate, a high-viscosity filtered fluid is prevented from leaking out of the filter 1 at the peripheral edge. A filter unit for a highly viscous fluid is disclosed. It is desirable that the tip portion of the pleat fold fold 7 is inflated and in close proximity to or in partial contact with the tip of adjacent fold folds.
[0009]
Depending on the type of high-viscosity fluid and the filtration conditions, the above-mentioned filter unit for high-viscosity fluid may deform the tip of the fold 81 on the filtrate outflow side during use as shown in FIG. Smooth flow may be hindered. In such a case, as shown in FIG. 3, a pleated disk-shaped body consisting of four layers folded in a zigzag manner, with two support members 32b and 32c overlapped on the filtrate outflow side B of the filter 31. By using, a smooth flow of the filtrate can be maintained. Furthermore, when using a wire mesh in which the metal wire 42 is woven on the support member 41, the metal wire 42 is preferably stacked so as to be in a bias (oblique) direction with respect to the longitudinal direction 43 of the folds (FIG. 4).
[0010]
Further, in the filter unit of the present invention, as shown in FIG. 6, in order to stably maintain the flow path of the filtrate, a liquid-permeable spacer 62 is provided between the folds 61 on one or both sides of the disk-like body. May be inserted. In that case, a liquid-permeable wire mesh 63 or the like is preferably attached to both surfaces or one surface of the disk-shaped body in order to prevent the spacer from being detached.
[0011]
Alternatively, in the collar portion 71, there may be a case where a ring sheet 72 made of a soft metal or a metal nonwoven fabric is overlapped only on one side (FIG. 7).
[0012]
Further, in the present invention, in the spinning pack casing 91, in order from the spinning solution discharge side 92, at least the spinneret 93, the pressure plate 94 for supporting the filter unit, any of the above-described high-viscosity fluid filter units 95, and the preceding stage. A spin pack (FIG. 9) is disclosed, which is mounted to include a filter 96 and a highly viscous fluid distribution plate 97. In the present invention, the filter unit refers to a unit assembled together with an accessory member so as to be convenient for use, for example, it is easy to attach and replace the filter to an apparatus or the like.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
In order to facilitate understanding of the present invention, the high viscosity fluid filter unit according to the present invention will be described in order according to a general manufacturing procedure for convenience, with reference to FIG. 1 and FIG. The unit is not limited by the production procedure.
[0014]
For the filter 1, a metal non-woven sheet-like fine filter for fine filtration is usually selected and used depending on the required filtration level. You may use a nonwoven fabric etc. For example, when a filter unit to be incorporated into a synthetic fiber spinning pack is manufactured, a filter having an opening of 40 μm or less is generally used.
[0015]
The sheet-like filter 1 is overlapped with a support member 2 for maintaining the shape, and is folded in a zigzag manner to widen the filtration area, and pleats are formed in parallel on both sides, thereby forming a pleated disc shape. Used as body 3. The cross-sectional shape in the direction perpendicular to the folds 7 of the plate-like body 3 may be a conventional zigzag pleated shape with sharp tips on both sides. However, preferably, as shown in FIG. 1, the support member 2 is overlapped on both sides of the sheet-like filter 1 and is pleated into three layers, and the front end portion of the fold 7 is rounded up on both sides, and adjacent folds are made. Processing into a pleated disk-shaped body 3 that is close to or partially in contact with the tip of the pleat 7. Between the folds 7, a flow path 8 for the filtrate is formed, so that a gap is provided to keep the flow. For the processing, a pleating machine for wire mesh may be used. Since the filter 1 and the support member 2 are not fixed at the time of pleating, the filter 1 can be easily processed without exerting excessive stress.
[0016]
The support member 2 is preferably a wire mesh having a relatively coarse mesh woven or knitted using a metal wire having a diameter of 0.17 mm or more in consideration of strength. In addition, you may utilize the nonwoven fabric etc. which used the metal wire. A stainless steel wire is used for the wire, and a wire mesh of plain weave, twill weave or tatami weave is often used. The depth and pitch of the pleats can be determined appropriately depending on the filtration chamber, required filtration area, mounting conditions, and the like. When it is intended to be mounted on the spinning head, it is generally preferable to design and manufacture the disc-like body 3 with a thickness of about 5 to 10 mm and a pitch of folds of about 3 to 5 mm. For example, if the pressure loss of filtration is small and deformation of the pleat surface can be ignored in long-term use, the support member can be placed only on one side of the filter in consideration of the pressure receiving direction during filtration. However, when it is intended to be incorporated into a synthetic fiber spinning pack, it is desirable to overlap both sides.
[0017]
Now, since the filter unit of the present invention is subjected to a considerably large filtration pressure, the spinning pack or the like is usually mounted on a pressure plate (FIG. 9: 94) that supports the filter unit. When filtration of high-viscosity fluid begins, filtered foreign matter gradually accumulates on the filter surface, and when the filtration chamber rises, the filter unit is sandwiched between the high-viscosity fluid to be filtered and the pressure plate. It receives a large compressive force and is easily deformed by being folded and pressed. If the folds are deformed, the filtration area of the filter is reduced, and the smooth flow of the high-viscosity fluid to be filtered is hindered, making it impossible to maintain the required filtration performance. Therefore, in the filter unit of the present invention, the tip portion of the fold fold 7 is inflated so as to be close to or partially in contact with the tip portions of the adjacent fold folds, so that deformation due to pressing is unlikely to occur. Even if it occurs, the flow path 8 of the highly viscous fluid is secured, and the filtration performance can be maintained for a long time.
[0018]
Actually, the filter unit for high-viscosity fluid of the present invention was attached to a spinning pack, and as a result, the quality of the filtrate was improved by eliminating the leakage of the filtrate, and the filtration pressure due to clogging etc. compared to the conventional flat type filter unit The ascent rate of decreased to about 1/3.
[0019]
However, depending on the type of polymer to be filtered and the filtration conditions, the filtration pressure gradually increased after the start of use, and there was no significant difference from the conventional flat type filter. As a result of the dismantling investigation, as shown in FIG. 8, the tip of the fold fold 81 on the filtrate outflow side B is deformed, and the height H of the fold fold 81 that was 5 mm before use is 4.2 to 4 Further, the fold folds 81 were in close contact with each other, and the filtrate outflow side flow passage 82 was blocked. Eventually, the substantial filtration area is considered to be in the same state as the flat filter.
[0020]
As a result of studying the above problem, an effective solution was found, which will be described. The order of explanation is irrelevant to effects and advantages. As shown in FIG. 3, one means is that two support members are stacked and stacked in the order of support member 32a / filter 31 / support member 32b / support member 32c from upstream A to downstream B, The flow path of the filtrate is positively secured. The support member is strengthened to prevent deformation, and the gap of the support member itself is used for the filtrate flow path.
[0021]
When the wire mesh such as the plain weave in which the wire in the warp direction and the transverse direction is orthogonal is used as the support member 41, the simplest means is the support member with respect to the longitudinal direction 43 of the folds as shown in FIG. The wire 42 which comprises 41 is piled up in a bias (diagonal) direction. Conventionally, as shown in FIG. 5, generally one wire 51 is processed in parallel with the longitudinal direction 53 of the folds. However, when the wire 52 is overlapped in parallel with the direction 53 of the folds, the wires of adjacent folds are in close contact with each other or mesh with each other due to the deformation of the fold end side of the folds, thereby obstructing the flow of the filtrate. The trend is big. The bias angle is preferably about 60 degrees or 30 degrees with respect to the longitudinal direction of the folds. Since the folded wire has a bias angle of 30 degrees, the possibility that the wires are brought into close contact with each other and the support member is engaged is reduced.
[0022]
As another means for preventing the deformation of the filter due to the filtration pressure, as illustrated in FIG. 6, a wire mesh, a spiral wire, metal particles, metal fibers, ceramic particles, etc. between the fold 61 and the fold 61, Alternatively, a liquid-permeable spacer 62 that allows high-viscosity fluid to pass through, such as these sintered porous molded bodies, can be inserted or filled. The spacers 62 are usually inserted on both sides of the filter unit. Furthermore, it is preferable to fix the spacer 62 with both sides of the filter unit so that the inserted and filled spacers 62 are not detached. Which of the above-described methods is appropriate may be selected according to the situation or used in combination.
[0023]
Next, the disk-like body is cut into a required planar shape. In the manufacturing procedure, the filter and the support member may be cut into a required shape and laminated, and then pleated. The disc-like body 3 is formed into a required planar shape, and then the peripheral edge portion 4 is compression-molded into a collar shape. The width of the collar 4 is usually about 3 to 5 mm. Then, ring sheets (including a metal O-ring) 5 made of a soft metal or a metal non-woven fabric are laminated on both surfaces of the formed fluffy portion 4. The soft metal is appropriately selected from aluminum, copper, lead, alloys thereof, mild steel and the like in consideration of corrosion caused by a filtering fluid. Depending on the conditions, a ring sheet stacked on one side is often sufficient. FIG. 7 shows an example in which the ring sheet 71 is overlapped on one side.
[0024]
Further, the collar 4 is covered with a thin metal plate 6 (72 in FIG. 7) from the peripheral side and pressed, and the filter 1, the support member 2, the ring sheets 5 and the covered thin metal plate 6 are crimped on the collar. Complete the filter unit. As a result, high-viscosity fluid bypass leakage at the periphery of the filter 1 can be prevented.
[0025]
Since a large filtration pressure is applied to the supply side of the high-viscosity fluid, it is used in a pressure-resistant housing or the like together with required members.
[0026]
The high viscosity fluid filter unit of the present invention is suitable for assembling together with a die as a main part of a spinning pack for filtering and spinning various high viscosity fluids. An example is shown in FIG. The spinning pack includes, in order from the spinning solution discharge side 92, at least a spinneret 93, a pressure plate 94 that supports a filter unit, a high-viscosity fluid filter unit 95 according to the present invention, and a front-stage filter 96. And a high viscosity fluid distribution plate 97. A sand filter is often used as the filter 96 in the previous stage.
[0027]
The above-described high viscosity fluid filter unit of the present invention solves the problem of spinning stock solution leaking from its peripheral portion, improves the reliability of the pleated type filter unit, prevents the deformation of the filter, and blocks the channel or clogs. The pressure increase speed of the filter is drastically reduced, and it is possible to substantially utilize a wide filtration area. As a result, the spin pack incorporating the filter unit of the present invention can enjoy the advantages of the pleated type filter unit with peace of mind.
[0028]
<Industrial applicability>
The filter unit of the present invention is manufactured in a shape and structure in which the filter is processed into a pleated shape, for example, the filtration area per spinning head is large and the high filtration pressure unique to high-viscosity fluid filtration is difficult to deform. Therefore, stable filtration operation is possible for a long time. Furthermore, the filter peripheral edge is pressure-bonded, and the high-viscosity fluid cannot bypass the filter, so that troubles caused by mixing of foreign substances do not occur, and a pressure-resistant filter having a large filtration area can be configured compactly.
[0029]
Therefore, it is suitable for filtering and removing foreign substances and gelled substances mixed in a polymer melted by heating or dissolving in a solvent in the production process of synthetic fibers, synthetic films and other organic polymer compound molded products. It is particularly useful as a spinning pack.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view (partial view) perpendicular to a fold showing an example of an embodiment of a filter unit for a highly viscous fluid according to the present invention.
FIG. 2 is a plan view of FIG.
FIG. 3 is a cross-sectional view (partial view) perpendicular to a fold, illustrating another embodiment of the filter unit for a highly viscous fluid of the present invention.
FIG. 4 is a perspective view (partial view) of a filter unit in which a plain weave wire mesh is used as a support member and the wire direction of the wire mesh is arranged in the direction of folds and a bias.
FIG. 5 is a perspective view (partial view) of a filter unit in which the wire direction is arranged in parallel to the direction of the folds.
FIG. 6 is a cross-sectional view (partial view) perpendicular to a fold, illustrating another embodiment of the filter unit for a highly viscous fluid of the present invention.
FIG. 7 is a cross-sectional view (partial view) perpendicular to a fold, illustrating another embodiment of the filter unit for a highly viscous fluid of the present invention.
FIG. 8 is a cross-sectional view showing a state in which the leading end of the fold fold on the outflow side is deformed and the flow path of the filtrate is closed.
FIG. 9 is a schematic cross-sectional view showing an example of a spin pack incorporating the filter unit for high viscosity fluid of the present invention.

Claims (12)

A pleated plate-like body (3) comprising a multilayer structure in which a support member (2 , 32a, 32b, 32c, 41 ) is superimposed on a sheet-like filter (1 , 31 ) and folded in a zigzag manner. The peripheral edge (4) of the body is formed into a flat collar, and at least one surface of the collar (4) is overlaid with a ring sheet (5) or a metal O-ring made of a soft metal or a metal nonwoven fabric. Further, by applying a thin metal plate (6) and crimping the filter, support member, ring sheet or metal O-ring overlaid on the collar-like portion (4) , and the thin metal plate thus covered, high viscosity is obtained at the periphery. A high viscosity fluid filter unit , wherein the fluid to be filtered is prevented from leaking out of the filter (1 , 31 ).   2. The filter unit for a high-viscosity fluid according to claim 1, wherein the pleat folds (7) have bulging tips and are adjacent to or partially in contact with the tips of adjacent folds. . The filter (31) is a sheet made of metal nonwoven fabric, the support members (32a, 32b, 32c) are wire meshes, and the disk-like body is on the filtrate outflow side ( B ) of the filter (31). The filter unit for high viscosity fluid according to claim 1 or 2, wherein the filter unit is a pleated plate-like body composed of four layers which are formed by overlapping two support members ( 32b, 32c ) and zigzag. .   The support member (41) is a wire mesh woven with a metal wire (42), and the metal wire is overlapped in the bias (oblique) direction with respect to the longitudinal direction (43) of the folds. The high viscosity fluid filter unit according to claim 1 or 2. The support member (41) is a wire mesh woven metal wire (42), characterized by being superimposed on the bias (diagonal) direction relative to the metal wire is they shed folding the longitudinal direction (43) The high viscosity fluid filter unit according to claim 3.   The high viscosity fluid filter unit according to claim 1, wherein a liquid-permeable spacer (62) is inserted between the folds (61) and the folds in the disc-like body.   The high viscosity fluid filter unit according to claim 6, wherein a liquid-permeable sheet (63) for preventing the spacer from being detached is stretched on the surface of the disk-shaped body.   7. A spinneret (91), a pressure plate (94) for supporting at least the spinneret (93) and the filter unit, in order from the spinning solution discharge side (92), in the spinning pack casing (91). A spinning pack comprising a viscous fluid filter unit (95), a front filter (96), and a highly viscous fluid distribution plate (97). The high-viscosity fluid filter according to claim 3, wherein, in the spinning pack casing (91), at least the spinneret (93) and the pressure plate (94) supporting the filter unit in order from the spinning liquid discharge side (92). A spinning pack comprising a unit, a front filter (96) and a highly viscous fluid distribution plate (97) . 5. The high-viscosity fluid filter according to claim 4, wherein, in the spinning pack casing (91), at least the spinneret (93) and the pressure plate (94) supporting the filter unit in order from the spinning solution discharge side (92). A spinning pack comprising a unit, a front filter (96) and a highly viscous fluid distribution plate (97) . The high viscosity fluid filter according to claim 5, wherein, in the spinning pack casing (91), at least the spinneret (93) and the pressure plate (94) supporting the filter unit in order from the spinning liquid discharge side (92). A spinning pack comprising a unit, a front filter (96) and a highly viscous fluid distribution plate (97) . The high-viscosity fluid filter according to claim 7, wherein, in the spinning pack casing (91), at least the spinneret (93) and the pressure plate (94) supporting the filter unit in order from the spinning solution discharge side (92). A spinning pack comprising a unit, a front filter (96) and a highly viscous fluid distribution plate (97) .

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