JP3802728B2 - Molten spinning base pack - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spinneret pack for melting and spinning a spinning melt composed of a polymer of a thermoplastic resin such as polyamide or polyester (hereinafter simply referred to as “polymer”).
[0002]
[Prior art]
Generally, polymers such as polyamide and polyester are melt-extruded by an extruder or the like, and then quantitatively supplied to a spinneret pack provided in a spin block by a quantitative supply means such as a gear pump, and a group of discharge holes perforated in the spinneret. And are each formed as a fiber.
[0003]
In general, a typical structure of the spinneret pack is as schematically illustrated in FIG. 1 (a schematic cross-sectional diagram). Here, the spinneret pack used in such a melt spinning method will be briefly described with reference to FIG.
[0004]
First, the main body part 1 of the spin pack base is divided into an upper pack member 1a, an intermediate pack member 1b, and a lower pack member 1c, so that a necessary spinning member can be incorporated therein, or after spinning. Disassembly and internal cleaning are easy at the time of reuse.
[0005]
That is, spinning members such as the filter media 2a to 2c, the packing 2d, the support member 3, the metal sand 4, the cylindrical cassette ring 5, and the base 6 are accommodated in the interior thereof, and the upper portion with respect to the intermediate pack member 1b. The pack member 1a and the lower pack member 1c are attached by fastening them from above and below with bolts 7a and 7b, which are fastening members, respectively.
[0006]
In such a spinneret pack, the polymer introduced from the polymer introduction hole Ha drilled in the upper pack member 1 a is filtered through the filter medium 2 c, the metal sand 4, and the filter medium 2 a provided immediately above the support member 3. After passing through each in turn, the structure is supplied to the support member 3.
[0007]
The filter medium 2c is formed such that its outer peripheral edge is surrounded by a filter medium with an aluminum rib having a metal rib such as an aluminum material. Therefore, the aluminum rib portion is sandwiched between the upper end surface of the cassette ring 5 and the upper pack member 1a of the pack main body and is crimped to prevent leakage of the polymer from this portion. As a matter of course, it also serves to filter out foreign matters having a relatively large particle size at this portion.
[0008]
Further, regarding the filter medium 2a provided immediately above the support member 3, in order to remove minute foreign matters contained in the polymer, it is required to filter to foreign matters having an extremely small average particle diameter. Inevitably, the filtration pressure increases. In addition, it is necessary to extend the life of the filter medium due to the clogging of the filter medium over time due to the trapping of foreign substances.
[0009]
For this reason, the filter medium 2a provided immediately above the support member 3 is required to have as large a filtration area as possible. That is, by reducing the amount of polymer passing per unit area of the filter medium 2a, the amount of foreign matter captured by the filter medium 2a can be reduced and the filtration pressure can be reduced.
[0010]
Therefore, generally, the polymer flow path is greatly enlarged immediately above the filter medium 2a, and then the diffused polymer is condensed by the polymer collecting holes Hb, and then distributed and supplied to the spinneret 6 as illustrated in FIG. A spinneret pack structure is required.
[0011]
In this case, the support member 3 plays a role of re-aggregating the polymer flowing through the polymer flow path that is greatly expanded while contracting the flow as small as possible while supporting a large filtration pressure on the filter medium 2a. And thereby, the support member 3 plays a role of uniformly mixing the polymers having various thermal histories in a certain sense by assembling the polymers having passed through different flow paths in the pack once again at the contraction portion. For this reason, the structure of the support member 3 is extremely important.
[0012]
This is because the support member 3 has a combined function as described above, and therefore the polymer is smoothly distributed from the support member 3 to the base 6 so that the abnormal retention of the polymer does not occur in this portion. This is because it becomes extremely difficult. If the abnormal retention of the polymer at the site of the support member 3 partially occurs, causing a heated abnormal retention polymer pyrolysis over a long period of time, it occurs a situation that they are mixed to a normal polymer.
[0013]
In particular, as illustrated in FIG. 1, a substantially uniformly over the entire surface, the supporting member 3, such as the distribution hole group Hc of the polymer is perforated, it can not be sufficiently control the flow of the polymer, the polymer However, the polymer tends to stay for a long time, so-called “dead space” is likely to occur, and the resulting thermal decomposition of the polymer tends to occur.
[0014]
When such a situation occurs, not only the quality of the obtained fiber becomes inferior, but also the problem that the melt spinning process itself becomes extremely unstable is caused. Even if melt spinning can be performed, there is a problem that fluffing due to single fiber breakage or hue abnormality is caused in the subsequent drawing process.
[0015]
[Problems to be solved by the invention]
In view of the problems of the conventional spinneret packs for melt spinning described above, the problem to be solved by the present invention is “to minimize the abnormal stagnation of the polymer in the spinneret packs and to obtain the fibers obtained thereby. It is an object of the present invention to provide a melt spinning die pack that can improve the quality and stabilize the process condition in the melt spinning process or the subsequent drawing process.
[0016]
[Means for Solving the Problems]
Here, as the present invention according to claim 1 of the claims, “a thermoplastic having at least a filter medium for removing foreign substances from the polymer and a support member for supporting the filter medium from below” is provided. In the spinneret pack for melt spinning the polymer,
In the support member,
The pressure receiving surface of the lower surface of the pressure receiving portion that supports the filtration pressure by the filter medium is formed only at least on the outer peripheral portion side of the support member, or formed between the outer peripheral portion side and a part of the inner peripheral portion side. A radial polymer collecting groove is formed on the lower surface of the pressure receiving portion, and is formed in the lower surface of the pressure receiving portion, and is formed on the lower surface of the pressure receiving portion. A spinneret pack for melt spinning ”is provided.
[0017]
According to the present invention relating to claim 2, the polymer that has passed through the filter material is distributed to the outer peripheral portion of the support member on the support upper surface of the support member in contact with the filter material. 2. A melt spinning base pack supplied by the radial distribution groove according to claim 1, wherein the radial distribution groove is provided. 3.
[0018]
According to the present invention relating to claim 3, the polymer once dispersed and distributed to the outer peripheral portion of the support member through the radial distribution groove provided on the support upper surface, 3. A melt spinning base pack according to claim 2, which has a contracted flow channel structure that contracts again through radial collecting grooves provided on the lower surface of the pressure receiving portion.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the melt spinning nozzle pack of the present invention will be described in detail with reference to the drawings. As the basic structure of the spinneret pack of the present invention, the one schematically illustrated in FIG. 1 described in the section of the prior art can be used as it is. Therefore, also in the present invention, the melt spinning nozzle pack schematically illustrated in FIG.
[0020]
First, the spinneret pack that can be used as it is in the present invention schematically illustrated in FIG. 1 will be described in a little more detail. Generally, in the spinneret pack for melt spinning, in addition to the metal sand 4, In some cases, fillers such as glass beads are used as parts. Therefore, first, the role of the metal sand 4 will be described. This is to reduce the residence time of the polymer introduced from the introduction hole Ha inside the main body of the spinneret pack and to uniformly heat the introduced polymer. Play a role.
[0021]
That is, by filling the metal sand 4, the occupied volume of the polymer in the pack body is reduced by the volume occupied by the filled metal sand 4. As a result, the polymer residence space in the pack is reduced by the occupied volume, and accordingly, the residence time in the pack is also reduced. Accordingly, since the polymer is not heated excessively in the bag, it is possible to suppress the thermal deterioration due to the long-term heating of the polymer.
[0022]
At this time, the metal sand 4 is heated in advance in the pack by the heat constantly supplied to the pack, and the temperature is raised to a certain temperature. For this reason, the metal sand 4 and the polymer introduced into the pack come into contact with each other in the pack, so that the polymer is quickly heated to a uniform temperature.
[0023]
That is, when the metal sand 4 is not filled, the polymer is gradually heated from the outer peripheral portion, whereas when the metal sand 4 is filled, the polymer is heated by contact with the filled metal sand 4. Also has the effect of being heated uniformly.
[0024]
Next, as a function of the assembly hole Hb that collects the polymer supplied from the support member 3 and introduces it into the base 6, the polymer residence time in the downstream portion of the filter medium 2 a in cooperation with the support member 3. Can be mentioned.
[0025]
Since the polymer flow in the melt spinneret pack is in a very stable laminar flow state, the streamlines are not interchanged between the polymer flowing on the outer peripheral side of the flow path and the polymer flowing on the inner peripheral side. Absent. Therefore, in order to homogenize the thermal history of the polymer flow by uniformly mixing the polymer in the cross section of the flow path, for example, a static mixer (static mixing element) such as a Kenix type or a Sulzer type is provided in the collecting hole Hb. ) May be installed.
[0026]
By the way, in FIG. 4 , the polymer melted by, for example, a melt extruder (not shown) or the like is introduced from an introduction hole Ha formed in the upper pack member 1a of the spinneret pack body into a gear pump ( not shown). After being quantitatively supplied by the quantitative supply means and passing through the filter medium 2c serving also as a sealing material, it passes through the metal sand 4 layer filled in the cassette ring 5 and supplied to the filter medium 2d.
[0027]
Then, the polymer that has passed through the filter medium 2d is contracted and aggregated by the support member 3 'provided immediately below. Further, the polymer collected in this way passes through the filter medium 2b also serving as a sealing material provided immediately above the base 6, and is finally discharged from a discharge hole (not shown) drilled in the base 6. Thus, it is molded as a fiber.
[0028]
One feature of the spinneret pack of the present invention configured as described above is that the polymer stays in a place where the "support member" is provided so as not to cause thermal deterioration due to excessive residence for a long time. This will be described in detail below with reference to the drawings.
[0029]
Figure 2 is an explanatory view of an embodiment illustrated schematically in "support member" as used in the melt-spinning spin pack of the present invention, FIG. (A) is a top plan view, (b) shows a side Cross-sectional views (cross-sectional view taken along the line XX in FIG. 5A) and FIG. 5C schematically illustrate the lower plan view. In FIGS. 1A and 1C, since the support member 3 ′ itself is formed in line symmetry, only the upper half of the support member 3 ′ is illustrated.
[0030]
In the support member 3 ′ illustrated in FIG. 2, reference numerals G <b> 0 to G <b> 6 are, for example, concentric circles for supplying the polymer that has passed through the filter medium 2 d provided in the cap pack illustrated in FIG. 1 to the downstream side. FIG. 2 shows distribution grooves (in the embodiment of FIG. 2, consisting of six rows of groove groups). Reference numerals P0 to P6 denote support upper surfaces for supporting the filter medium 2d so that the filter medium 2d is not deformed by receiving a large pressure.
[0031]
Further, reference symbols S1 to S16 (in which S9 to S16 are not shown) are pressure receiving portions of the support member 3 ′, and reference symbols R0 to R15 (in which R9 to R15 are not shown). These indicate polymer collecting grooves formed radially on the lower surface of the pressure receiving portions S1 to S16, respectively.
[0032]
In that case, the annular groove | channel D is provided in the lower surface of pressure receiving part S1-S16. Therefore, in this annular groove D portion, it is not possible to take a large filtration pressure acting on the filter medium 2d, and the pressure receiving surface shown in FIG. Only in the portion shown, it is supported by the intermediate pack member 1b and receives the filtration pressure. In FIG. 2B, a boundary line between the intermediate pack member 1b and the support member 3 ′ is shown by a two-dot chain line.
[0033]
For this reason, unlike the case of supporting the filtration pressure on the entire lower surface of the pressure receiving portions S1 to S16 without providing the annular groove D as in the prior art, the problem of strength that the support member 3 ′ itself is easily deformed. There is. However, this is not a big problem in practice, and the following great effects can be expected.
[0034]
In general, the support member 3 ′ has a structure that can be detachably separated from the intermediate pack member 1b in order to facilitate assembly and disassembly and to facilitate internal cleaning. For this reason, a slight gap is generated on the contact surface with the intermediate pack member 1b on which the support member 3 'is mounted even if the manufacturing accuracy is increased and the adhesion of the contact surface is increased. The polymer easily enters.
[0035]
In addition, these parts are not discarded after being used only once, but are assumed to be used repeatedly. For this reason, even if the adhesion of the contact surface is increased, it is unavoidable that the repeated use of the contact surface deteriorates the accuracy of the contact surface and a gap is generated, which prevents the polymer from entering the gap. There are limits.
[0036]
For these reasons stated above, the polymer that has entered the gap, over a long period of time, to stay on the lower surface of the pressure receiving portion S1~S16 of the support member 3 ', become be prolonged or heated, thermal degradation Will be triggered. If such a polymer that has undergone thermal degradation is mixed with a polymer that does not undergo thermal degradation, the quality of the resulting fiber will be poor.
[0037]
In addition, the melt spinning process itself becomes very unstable. Further, even if melt spinning can be performed, the problems already described in the section of the prior art, such as generation of fuzz due to single fiber breakage and hue abnormality in the subsequent drawing process, are caused.
[0038]
Therefore, by providing the annular groove D on the lower surface of the pressure receiving portions S1 to S16, the annular groove D portion does not receive a large filtration pressure acting on the filter medium 2d. It is important to apply the filtration pressure only to the pressure receiving surfaces indicated by A16 and B1 to B16 (for emphasis, the portion indicated by the shaded area consisting of a number of points). In this way, by reducing the ratio of the pressure receiving surfaces A1 to A16 and B1 to B16 as much as possible, the possibility that the polymer stays in this portion can be reduced as much as possible.
[0039]
A radial polymer collecting groove R0 is provided on the lower surface of the pressure receiving portions S1 to S16, and the polymer flow expanded on the upstream side of the filter medium 2d is contracted on the downstream side of the filter medium 2d and supplied to the base 6. -R15 is formed. The radial polymer collecting grooves R0 to R15 serve to introduce the polymer flowing on the lower surfaces of the pressure receiving portions S1 to S16 while smoothly moving toward the collecting hole Hb and contracting the polymer to the collecting hole Hb.
[0040]
As described above, by providing the annular groove D, the pressure receiving surfaces A1 to A16 and B1 to B16 on the lower surface of the pressure receiving portions S1 to S16 that support the filtration pressure by the filter medium 2d are at least the outer periphery of the support member 3 ′. It will be formed on the part side and the inner peripheral part side. At this time, if the problem in strength of the support member 3 ′ is solved, the pressure receiving surfaces of the lower surfaces of the pressure receiving portions S1 to S16 that support the filtration pressure by the filter medium 2d are at least the outer peripheral side, that is, the pressure receiving surfaces A1 to A16. It is more preferable to form only in the case.
[0041]
The groove depth of the annular groove D is merely a design matter and does not need to be particularly limited. However, it is preferable from the viewpoint of preventing thermal deterioration to set the amount of residence and the residence time of the polymer in this portion as small as possible. Therefore, if the groove depth of the annular groove D is, for example, about 0.3 to 3 mm, it is preferable because the flow of the polymer can be made smooth and the retention amount (retention time) can be reduced.
[0042]
Next, another embodiment of the melt spinning die pack of the present invention will be described in detail with reference to FIG. FIG. 3 is an explanatory view schematically illustrating the conventional support member 3 illustrated in FIG. 1 and another support member 3 ″ instead of the support member 3 ′ in FIG.
[0043]
However, in FIG. 3, the figure (a) is a top plan view, the figure (b) is a sectional side view (sectional view taken along the line XX of the figure (a)), and the figure (c) is a sectional side view (figure ( (d) is a cross-sectional view taken along the line Y-Y), and FIG. (d) schematically illustrates the lower plan view. In FIGS. 2B and 2C, only the upper half part of the support member 3 ″ is shown.
[0044]
As shown in FIG. 3, the filter medium 2d includes support upper surfaces P1 ′, P2 ′, P3 ′ and P4 ′ for supporting the filter medium 2d (however, P3 ′ and P4 ′ are not shown). Support). The support upper surfaces P1 ′ to P4 ′ have radial distribution grooves G0 ′ to G35 ′ (however, G17 ′ to G35 ′ that distribute the polymer that has passed through the filter medium 2d to the outer peripheral portion of the support member 3 ″. Is not shown).
[0045]
Therefore, the polymer from which the foreign matter has been removed by the filter medium 2d is once distributed to the outer peripheral portion of the support member 3 ″ through these distribution grooves G0 ′ to G35 ′. Regardless of which part of the polymer flow that has passed through the part, all of the polymer flow is once equally distributed to the outer peripheral portion of the support member 3 ″.
[0046]
After that, radial polymer collecting grooves R0 ′ to R35 ′ (however, R17 ′ to R35 ′ are not shown) provided from the outer peripheral portion of the support upper surfaces P1 ′ to P4 ′ of the support member 3 ″ to the lower surface of the pressure receiving portion. , Are supplied to the collecting hole Hb after being contracted and assembled.
[0047]
At that time, an annular groove D ′ is provided on the lower surface of the pressure receiving portion, and the pressure receiving surface that receives the generation of the filtration pressure due to the polymer passing through the filter medium 2d on the lower surface of the pressure receiving portion is shown in FIG. It is composed only of A1 ′ to A35 ′ (however, A17 ′ to A35 ′ are not shown) highlighted in shades at many points.
[0048]
Therefore, in this embodiment, it is formed only by the pressure receiving surfaces A1 to A16 on the outer peripheral side as the pressure receiving surface on the lower surface of the pressure receiving portion that supports the filtration pressure by the filter medium 2d, and is not formed on the inner peripheral side. .
[0049]
As described above, in the present invention, the pressure receiving surface shape of the lower surface of the pressure receiving portion is extremely important, and such a pressure receiving surface shape will be described in detail with reference to FIG. FIG. 4 is an explanatory diagram schematically illustrating various embodiments regarding the pressure receiving surface shape of the lower surface of the pressure receiving portion of the “support member” used in the melt spinning base pack of the present invention.
[0050]
In FIG. 4A to FIG. 4F, the pressure receiving portions for contacting the intermediate pack member 1b and receiving the filtration pressure generated by the filter medium 2d are shaded and highlighted at a number of points. It is the part which was done. In addition, in FIG. (A)-(f), the part represented by the fan shape took out only one of many fan-shaped pressure receiving surfaces, and illustrated typically.
[0051]
【The invention's effect】
As described above, according to the spinneret pack of the present invention, the abnormal stagnation of the polymer in the spinneret pack can be reduced as much as possible, thereby improving the quality of the fiber obtained and the melt spinning step or There is an extremely remarkable effect of providing a melt spinning base pack that can stabilize the process condition in the subsequent stretching process.
[Brief description of the drawings]
FIG. 1 is a schematic front cross-sectional view schematically illustrating a generally used melt spinning die pack.
FIGS. 2A and 2B are explanatory views schematically illustrating an embodiment of a “support member” used in the melt spinning die pack of the present invention, in which FIG. 2A is a top plan view and FIG. 2B is a side view; sectional view (a-a arrow sectional view of Fig. (a)), and FIG. (c) is an illustration of example lower plan view of the respective schematically.
FIG. 3 is an explanatory view schematically showing another embodiment of a “support member” used in the melt spinning die pack of the present invention, in which FIG. Is a side sectional view (sectional view taken along the line XX of FIG. (A)), FIG. (C) is a side sectional view (sectional view taken along the line YY of FIG. (D)), and FIG. Each of the plan views is schematically illustrated.
FIG. 4 is an explanatory view schematically illustrating various embodiments regarding the pressure receiving surface shape of the lower surface of the pressure receiving portion of the “support member” used in the die pack for melt spinning of the present invention.

Claims (3)

In a spinneret pack for melt spinning a thermoplastic polymer, provided with at least a filter medium for removing foreign substances from the polymer and a support member for supporting the filter medium from below,
In the support member,
The pressure-receiving surface of the lower surface of the pressure-receiving portion that supports the filtration pressure by the filter medium is formed only at least on the outer peripheral portion side, or formed on the outer peripheral portion side and a part of the inner peripheral portion side, and formed in the intermediate portion In addition, a radial polymer gathering groove is formed on the lower surface of the pressure receiving portion, and the polymer flow expanded on the upstream side of the filter medium is contracted on the downstream side of the filter medium and supplied to the base. A spinneret pack for melt spinning. The radial distribution groove according to claim 1, wherein a radial distribution groove for distributing the polymer that has passed through the filter material to the outer peripheral portion of the support member is provided on a support upper surface of the support member in contact with the filter material. Nozzle pack for melt spinning supplied by a distribution groove. The polymer once dispersed and distributed to the outer peripheral portion of the support member via the radial distribution groove provided on the upper surface of the support is again contracted through the radial collecting groove provided on the lower surface of the pressure receiving portion. The melt spinning die pack according to claim 2, which has a contracted flow channel structure.

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