A polylactic acid fiber spinneret with double concave-convex special-shaped cross section

Abstract

The present invention provides a polylactic acid fiber spinneret with a double concave-convex special-shaped cross section, and relates to the technical field of polylactic acid fiber spinning. The polylactic acid fiber spinneret with a double concave-convex special-shaped cross section comprises an upper plate, a lower plate, a seat ring, a liquid guide cavity, a liquid guide groove, and a liquid guide hole. The present invention provides multiple groups of inserts with spinnerets, so that multiple groups of spinnerets are used in combination, which effectively solves the problem of processing difficulties after increasing the length of the spinnerets, and the detachable connection simplifies the work of cleaning the spinnerets. A sink is provided on the lower wall of the lower plate, and the weight of the spinneret is greatly reduced by hollowing out. Multiple groups of spinnerets are arranged in increasing order from top to bottom, and a nano alloy ion layer is provided on the inner wall of the spinneret to increase the smoothness, which can release part of the elastic potential energy of the polylactic acid melt to a certain extent, reduce the expansion ratio of the primary silk, and maintain the stability of spinning. The nano alloy ion layer also plays an anti-corrosion role.

Description

Technical Field

[0001] The invention relates to the technical field of polylactic acid fiber spinning, in particular to a polylactic acid fiber spinneret with a double concave-convex special-shaped cross section. Background Art

[0002] With the rapid development of the chemical fiber industry, polyester fiber is increasingly used in clothing chemical fiber products. my country's polyester consumption has reached 60 million tons. The greenhouse gas emitted by polyester throughout its life cycle has a negative impact on the earth's climate change. In addition, polyester waste cannot be degraded, polluting water sources and land resources, and has become a threat to human survival. In response to this problem, we have made improvements and used degradable bio-based fiber polylactic acid to replace polyester; in addition, most of the existing fibers have a circular cross-sectional shape. Textiles made from fibers with a circular cross-sectional shape have the disadvantages of poor fluffiness, poor breathability, rough texture, and uncomfortable clothing. Therefore, we have made improvements to this and proposed a method as shown in the attached Fig.11 The double concave-convex fuzzy and fluffy polylactic acid fiber and its spinneret are shown.

[0003] However, it was found in actual applications that the spinneret with the double concave-convex special-shaped cross-section structure has an excessively large primary filament expansion ratio, which can easily lead to melt rupture and non-forming, affecting the stability of spinning. The main reason is that the elastic potential energy of the polylactic acid melt in the original spinneret structure cannot be released, and the spinneret with the double concave-convex special-shaped cross-section structure increases the contact area with the melt, and the friction between the melt and the hole wall increases, resulting in an increase in the expansion ratio. The conventional method is to solve this problem by increasing the aspect ratio of the spinneret, but the spinneret is a micropore, and the increased length makes processing difficult, and at the same time, the plate thickness needs to be increased, resulting in an increase in the overall weight. At the same time, after the hole length is increased, the difficulty of subsequent cleaning work is greatly increased. There is a certain amount of acid in the polylactic acid fiber, and the inner wall of the spinneret in the original structure is more easily corroded by the acid, resulting in a rough outer wall of the filament bundle. In summary, it is necessary to improve and optimize the spinneret structure of the polylactic acid fiber with a double concave-convex special-shaped cross-section. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the present invention provides a polylactic acid fiber spinneret with a double concave-convex special-shaped cross-section, which solves the problems of the polylactic acid fiber spinneret with a double concave-convex special-shaped cross-section in the prior art, such as too large primary fiber expansion ratio, difficulty in cleaning the spinneret holes, and the inner wall of the spinneret holes being easily corroded by acid.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a polylactic acid fiber spinneret with a double concave-convex special-shaped cross-section, comprising an upper plate, a lower plate, a seat ring, a liquid guide cavity, a liquid guide groove and a liquid guide hole, wherein the upper plate and the lower plate are distributed up and down, the seat ring is arranged on the upper wall of the upper plate, the liquid guide cavity is arranged on the upper wall of the seat ring, the liquid guide groove is arranged on the inner lower wall of the liquid guide cavity, the liquid guide hole is arranged on the inner lower wall of the liquid guide groove and the lower end of the liquid guide hole is connected with the lower wall of the upper plate, a sink groove connected with the lower wall of the lower plate is arranged inside the lower plate, a plurality of groups of mounting seats are arranged on the inner upper wall of the sink groove, an insulation structure for insulation is arranged inside the sink groove and outside the mounting seat, and the mounting An insert sleeve is detachably connected to the inner wall of the seat, and a pulling structure for facilitating the removal of the insert sleeve is provided on the lower wall of the insert sleeve. A plurality of groups of inserts are detachably connected to the inner wall of the insert sleeve, and the plurality of groups of inserts are sequentially arranged on the inner wall of the insert sleeve according to an up-and-down distribution. A positioning structure is provided between two upper and lower adjacent groups of the plurality of groups of inserts, and spinnerets which penetrate vertically are provided on the inner walls of the plurality of groups of inserts. The spinnerets are composed of a central portion, convex portions arranged on opposite sides of the central portion when viewed from above, and concave portions arranged on the other two sides adjacent to the convex portions when viewed from above. The inner wall of the spinneret is provided with a coating structure for improving the wear resistance, smoothness and corrosion resistance of the spinneret.

[0008] Preferably, the thermal insulation structure is a thermal insulation layer, the thermal insulation layer is arranged between the inner wall of the sink and the outer wall of the mounting seat, and the lower wall of the thermal insulation layer is flush with the lower end of the mounting seat.

[0009] Preferably, a first mounting cavity penetrating the lower wall of the mounting seat is provided inside the mounting seat, the insert sleeve is slidably connected to the inner wall of the first mounting cavity, and the insert sleeve is detachably connected to the mounting seat by two sets of first screws.

[0010] Preferably, the drawing structure comprises two groups of drawing holes, the two groups of drawing holes are both arranged on the lower wall of the insert sleeve, and the inner side walls of the two groups of drawing holes are both provided with internal threads.

[0011] Preferably, a second installation cavity communicating with the lower wall of the insert sleeve is provided inside the insert sleeve, and multiple groups of inserts are slidably connected to the inner wall of the second installation cavity in sequence according to the upper and lower distributions, and multiple groups of inserts are detachably connected to the insert sleeve through two groups of second screws.

[0012] Preferably, the positioning structure includes multiple groups of positioning rings and multiple groups of positioning grooves, the multiple groups of positioning rings are respectively arranged on the upper walls of the multiple groups of inserts except the uppermost group, the multiple groups of positioning grooves are respectively arranged on the lower walls of the multiple groups of inserts except the lowermost group, and the upper and lower adjacent groups of the multiple groups of inserts are positioned and connected by positioning rings and positioning grooves.

[0013] Preferably, the inner cavity sizes of the spinneret holes in the plurality of groups of inserts increase in sequence from top to bottom, and the increasing size of each layer is one fiftieth of the inner cavity size of the spinneret holes in the upper layer.

[0014] Preferably, the lower edges of the plurality of groups of spinneret holes are all provided with arc chamfers.

[0015] Preferably, the inner wall of the lower plate is provided with a first liquid inlet for penetrating the trough and the upper wall of the lower plate, the upper wall of the mounting seat is provided with a second liquid inlet which is vertically connected with the first liquid inlet, the upper wall of the insert sleeve is provided with a third liquid inlet which is vertically connected with the second liquid inlet, and the spinneret hole is connected with the third liquid inlet.

[0016] Preferably, the coating structure is a nano alloy ion layer, and the nano alloy ion layer is arranged on the inner wall of the spinneret hole.

[0017] (III) Beneficial effects

[0018] The present invention provides a polylactic acid fiber spinneret with a double concave-convex special-shaped cross section, which has the following beneficial effects:

[0019] 1. Compared with the prior art, the polylactic acid fiber spinneret with double concave-convex special-shaped cross-section is provided with multiple groups of inserts, each group of inserts is provided with spinneret holes, and then the positioning ring and the positioning groove are used to connect, so that the multiple groups of spinneret holes can be used in combination, which effectively solves the problem of processing difficulties after increasing the length of the spinneret holes, and the detachable connection simplifies the work of cleaning the spinneret holes.

[0020] 2. Compared with the prior art, the polylactic acid fiber spinneret with double concave-convex special-shaped cross-section has a sink groove arranged on the lower wall of the lower plate, which greatly reduces the weight of the spinneret through hollowing out. An insulation layer is arranged inside the sink groove, which can effectively avoid the temperature fluctuation of the melt in the spinneret hole and maintain the spinning stability.

[0021] 3. Compared with the prior art, the polylactic acid fiber spinneret with double concave-convex special-shaped cross-section has multiple groups of spinneret holes arranged in increasing order from top to bottom, and a nano-alloy ion layer is arranged on the inner wall of the spinneret hole to increase the smoothness, which can release part of the elastic potential energy of the polylactic acid melt to a certain extent, reduce the expansion ratio of the primary silk, and maintain spinning stability.

[0022] 4. Compared with the prior art, the nano alloy ion layer of the polylactic acid fiber spinneret with double concave-convex special-shaped cross section also plays an anti-corrosion role, effectively prolongs the service life of the insert, reduces the number of replacements, and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the overall structure of the present invention from above;

[0025] Figure 3 For the present invention Figure 2 A partial enlarged view of the middle A;

[0026] Figure 4 It is a partial cross-sectional schematic diagram of the connection structure between the lower plate and the mounting seat of the present invention;

[0027] Figure 5 It is a partial cross-sectional view of the lower plate, the mounting seat, the insert sleeve and the multiple sets of insert block connection structure of the present invention;

[0028] Figure 6 A partial cross-sectional view of the internal structure of the mounting seat of the present invention;

[0029] Figure 7 It is a partial cross-sectional view of the internal structure of the insert sleeve of the present invention;

[0030] Figure 8 It is a partial cross-sectional view of the internal structure of an insert located at a non-bottom and non-top position among the multiple groups of inserts of the present invention;

[0031] Fig. 9 For the present invention Figure 8 A partial enlarged view of point B in the middle;

[0032] Fig.10 It is a schematic diagram of the upward structure of the lowest group of inserts among the multiple groups of inserts of the present invention;

[0033] Fig.11 This is a partially enlarged view of the cross section of a polylactic acid fiber with a double concave-convex special-shaped cross section produced by using the polylactic acid fiber spinneret with a double concave-convex special-shaped cross section provided by the present invention.

[0034] Among them, 1. upper plate; 2. lower plate; 201. sink; 202. first liquid inlet; 3. seat ring; 4. liquid guide cavity; 5. liquid guide groove; 6. liquid guide hole; 7. insulation layer; 8. mounting seat; 801. first mounting cavity; 802. second liquid inlet; 9. insert sleeve; 901. second mounting cavity; 902. third liquid inlet; 10. first screw; 11. insert; 12. spinneret hole; 1201. center part; 1202. convex part; 1203. concave part; 13. drawing hole; 14. second screw; 15. nano alloy ion layer; 16. arc chamfer; 17. positioning ring; 18. positioning groove. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example:

[0037] like Figures 1 to 10 As shown, an embodiment of the present invention provides a polylactic acid fiber spinneret with a double concave-convex special-shaped cross-section, comprising an upper plate 1, a lower plate 2, a seat ring 3, a liquid guide cavity 4, a liquid guide groove 5 and a liquid guide hole 6. The upper plate 1 and the lower plate 2 are distributed up and down, the seat ring 3 is arranged on the upper wall of the upper plate 1, the liquid guide cavity 4 is arranged on the upper wall of the seat ring 3, the liquid guide groove 5 is arranged on the inner lower wall of the liquid guide cavity 4, the liquid guide hole 6 is arranged on the inner lower wall of the liquid guide groove 5, and the lower end of the liquid guide hole 6 is connected with the lower wall of the upper plate 1.

[0038] In order to increase the thickness of the plate without increasing the weight, a sink 201 penetrating the lower wall of the lower plate 2 is provided inside the lower plate 2, and a plurality of mounting seats 8 are provided on the inner upper wall of the sink 201. The sink 201 is hollowed out to reduce the overall weight and avoid difficulties in maintenance operations.

[0039] In order to improve the spinning stability, a heat preservation structure for heat preservation is arranged inside the trough 201 and outside the mounting seat 8. The heat preservation structure is a heat preservation layer 7. The heat preservation layer 7 is arranged between the inner wall of the trough 201 and the outer wall of the mounting seat 8. The lower wall of the heat preservation layer 7 is flush with the lower end of the mounting seat 8. The heat preservation layer 7 can be used to insulate the mounting seat 8, the insert sleeve 9 and the multiple groups of inserts 11 located inside the insert sleeve 9, so as to avoid the temperature fluctuation of the melt inside the spinneret hole 12 and improve the spinning stability.

[0040] In order to facilitate the cleaning of the spinneret hole 12, the inner wall of the mounting seat 8 is detachably connected with an insert sleeve 9, and the mounting seat 8 is provided with a first mounting cavity 801 which is connected with the lower wall of the mounting seat 8. The insert sleeve 9 is slidably connected to the inner wall of the first mounting cavity 801, and the insert sleeve 9 is detachably connected to the mounting seat 8 through two sets of first screws 10. Through the detachable connection between the insert sleeve 9 and the mounting seat 8, when maintaining the spinneret hole 12, it is not necessary to remove the entire plate, and only the insert sleeve 9 that blocks the hole needs to be removed;

[0041] In order to facilitate the removal of the insert sleeve 9, a pulling structure for conveniently removing the insert sleeve 9 is provided on the lower wall of the insert sleeve 9, and the pulling structure includes two groups of pulling holes 13, both of which are arranged on the lower wall of the insert sleeve 9, and the inner side walls of the two groups of pulling holes 13 are provided with internal threads. When removing the insert sleeve 9, first unscrew the first screw 10, and then screw the first screw 10 into the pulling hole 13, and the insert sleeve 9 can be easily removed from the first installation cavity 801 by pulling the first screw 10 downward;

[0042] In order to facilitate the processing of the spinneret 12, the inner wall of the insert sleeve 9 is detachably connected with multiple groups of inserts 11, and the multiple groups of inserts 11 are sequentially arranged on the inner wall of the insert sleeve 9 according to the upper and lower distribution. The insert sleeve 9 is provided with a second installation cavity 901 which is connected with the lower wall of the insert sleeve 9. The multiple groups of inserts 11 are sequentially slidably connected to the inner wall of the second installation cavity 901 according to the upper and lower distribution. The multiple groups of inserts 11 are detachably connected to the insert sleeve 9 through two groups of second screws 14. After the spinneret 12 is extended, the processing difficulty of the spinneret 12 is reduced by splicing multiple groups of inserts 11. After the multiple groups of inserts 11 are combined, the extended spinneret 12 is obtained to improve the aspect ratio, reduce the expansion ratio of the primary silk, and improve the spinning stability.

[0043] In order to facilitate installation, a positioning structure is provided between two adjacent groups of multiple groups of inserts 11, and the positioning structure includes multiple groups of positioning rings 17 and multiple groups of positioning grooves 18. The multiple groups of positioning rings 17 are respectively arranged on the upper walls of the multiple groups of inserts 11 except the uppermost group, and the multiple groups of positioning grooves 18 are respectively arranged on the lower walls of the multiple groups of inserts 11 except the lowermost group. The upper and lower adjacent groups of multiple groups of inserts 11 are positioned and connected by the positioning rings 17 and the positioning grooves 18, and the positioning rings 17 and the positioning grooves 18 facilitate the positioning and installation of the multiple groups of inserts 11 with each other.

[0044] In order to release the elastic potential energy of the polylactic acid melt, the inner walls of the multiple groups of inserts 11 are all provided with spinnerets 12 that penetrate from top to bottom. The spinnerets 12 are composed of a central portion 1201, convex portions 1202 arranged on opposite sides of the central portion 1201 under a top-down projection, and concave portions 1203 arranged on the other two sides adjacent to the convex portions 1202 under a top-down projection of the central portion 1201. The inner cavity sizes of the spinnerets 12 in the multiple groups of inserts 11 increase in sequence from top to bottom, and the increasing size of each layer is one-fiftieth of the inner cavity size of the upper layer of the spinnerets 12. The lower edges of the multiple groups of spinnerets 12 are all provided with arc chamfers 16. The lower plate 2 The inner wall is provided with a first liquid inlet 202 for penetrating the sink 201 and the upper wall of the lower plate 2, the upper wall of the mounting seat 8 is provided with a second liquid inlet 802 which is vertically connected with the first liquid inlet 202, the upper wall of the insert sleeve 9 is provided with a third liquid inlet 902 which is vertically connected with the second liquid inlet 802, the spinneret hole 12 is connected with the third liquid inlet 902, the multiple groups of spinneret holes 12 are arranged in increasing order from top to bottom, and a nano alloy ion layer 15 is arranged on the inner wall of the spinneret hole 12 to increase the smoothness, which can release part of the elastic potential energy of the polylactic acid melt to a certain extent, reduce the expansion ratio of the primary silk, and maintain the spinning stability;

[0045] In order to reduce the friction of the hole wall and improve the corrosion resistance, the inner wall of the spinneret hole 12 is provided with a coating structure for improving the wear resistance, smoothness and corrosion resistance of the spinneret hole 12. The coating structure is a nano alloy ion layer 15. The nano alloy ion layer 15 is arranged on the inner wall of the spinneret hole 12. The nano alloy ion layer 15 can effectively improve the smoothness of the inner wall of the spinneret hole 12 and reduce friction. The nano alloy ion layer 15 also has the characteristics of high temperature resistance and corrosion resistance, which effectively improves the service life of the spinneret hole 12. After the coating structure is worn, it can be repaired by re-coating.

[0046] Working principle: The overall weight is reduced by hollowing out the sink 201 to avoid difficulties in maintenance operations; the insulation layer 7 can be used to insulate the mounting seat 8, the insert sleeve 9 and the multiple sets of inserts 11 located inside the insert sleeve 9 to avoid temperature fluctuations of the melt inside the spinneret 12 and improve spinning stability; the insert sleeve 9 is detachably connected to the mounting seat 8, so that when maintaining the spinneret 12, it is not necessary to remove the entire plate, but only the insert sleeve 9 that blocks the hole needs to be removed; when removing the insert sleeve 9, first unscrew the first screw 10, and then screw the first screw 10 into the drawing hole 13; the insert sleeve 9 can be easily removed from the first mounting cavity 801 by pulling the first screw 10 downward; after the spinneret 12 is extended, the processing difficulty of the spinneret 12 is reduced by splicing multiple sets of inserts 11; after the multiple sets of inserts 11 are combined, the extended spinneret is obtained. The wire hole 12 is used to improve the aspect ratio, reduce the expansion ratio of the primary silk, and improve the spinning stability. The upper and lower adjacent groups of multiple groups of inserts 11 are positioned and connected by positioning rings 17 and positioning grooves 18. The positioning rings 17 and positioning grooves 18 facilitate the positioning and installation of multiple groups of inserts 11 relative to each other. The multiple groups of spinneret holes 12 are arranged in increasing order from top to bottom, and a nano-alloy ion layer 15 is arranged on the inner wall of the spinneret hole 12 to increase the smoothness, which can release part of the elastic potential energy of the polylactic acid melt to a certain extent, reduce the expansion ratio of the primary silk, and maintain spinning stability. The nano-alloy ion layer 15 can effectively improve the smoothness of the inner wall of the spinneret hole 12 and reduce friction. The nano-alloy ion layer 15 also has the characteristics of high temperature resistance and corrosion resistance, which effectively improves the service life of the spinneret hole 12. The coating structure can be repaired by re-coating after wear.

[0047] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A polylactic acid fiber spinneret with a double concave-convex special-shaped cross section, characterized in that: The invention comprises an upper plate (1), a lower plate (2), a seat ring (3), a liquid guide cavity (4), a liquid guide groove (5) and a liquid guide hole (6), wherein the upper plate (1) and the lower plate (2) are arranged in an upper and lower arrangement, the lower plate (2) is provided with a sink groove (201) penetrating the lower wall of the lower plate (2), a plurality of groups of mounting seats (8) are provided on the upper inner wall of the sink groove (201), a heat-insulating structure for heat insulation is provided inside the sink groove (201) and outside the mounting seats (8), an insert sleeve (9) is detachably connected to the inner wall of the mounting seats (8), a pull-out structure for conveniently removing the insert sleeve (9) is provided on the lower wall of the insert sleeve (9), a plurality of groups of insert blocks (11) are detachably connected to the inner wall of the insert sleeve (9), and the plurality of groups of insert blocks (11) are arranged in an upper and lower arrangement. The cloth is sequentially arranged on the inner wall of the insert sleeve (9), and a positioning structure is arranged between two adjacent groups in the multiple groups of inserts (11). The inner walls of the multiple groups of inserts (11) are each provided with a spinneret hole (12) that passes through from top to bottom. The inner cavity size of the spinneret holes (12) in the multiple groups of inserts (11) increases in sequence from top to bottom. The spinneret hole (12) consists of a central part (1201), a convex part (1202) arranged on two opposite sides of the central part (1201) when viewed from above, and a concave part (1203) arranged on the other two sides adjacent to the convex part (1202) when viewed from above. The inner wall of the spinneret hole (12) is provided with a coating structure for improving the wear resistance, smoothness and corrosion resistance of the spinneret hole (12).

2. The polylactic acid fiber spinneret with double concave-convex special-shaped cross-section according to claim 1, characterized in that: The thermal insulation structure is a thermal insulation layer (7), and the thermal insulation layer (7) is arranged between the inner wall of the sink (201) and the outer wall of the mounting seat (8), and the lower wall of the thermal insulation layer (7) is flush with the lower end of the mounting seat (8).

3. The polylactic acid fiber spinneret with double concave-convex special-shaped cross-section according to claim 2, characterized in that: A first mounting cavity (801) is provided inside the mounting seat (8) and is communicated with the lower wall of the mounting seat (8). The insert sleeve (9) is slidably connected to the inner wall of the first mounting cavity (801). The insert sleeve (9) is detachably connected to the mounting seat (8) via two sets of first screws (10).

4. The polylactic acid fiber spinneret with double concave-convex special-shaped cross-section according to claim 3, characterized in that: The drawing structure comprises two groups of drawing holes (13), the two groups of drawing holes (13) are both arranged on the lower wall of the insert sleeve (9), and the inner side walls of the two groups of drawing holes (13) are both provided with internal threads.

5. The polylactic acid fiber spinneret with double concave-convex special-shaped cross section according to claim 4, characterized in that: The insert sleeve (9) is provided with a second installation cavity (901) which is in communication with the lower wall of the insert sleeve (9), and the plurality of groups of inserts (11) are slidably connected to the inner wall of the second installation cavity (901) in sequence according to the upper and lower distribution. The plurality of groups of inserts (11) are detachably connected to the insert sleeve (9) via two groups of second screws (14).

6. The polylactic acid fiber spinneret with double concave-convex special-shaped cross section according to claim 5, characterized in that: The positioning structure comprises a plurality of groups of positioning rings (17) and a plurality of groups of positioning grooves (18). The plurality of groups of positioning rings (17) are respectively arranged on the upper walls of the plurality of groups of inserts (11) except the uppermost group. The plurality of groups of positioning grooves (18) are respectively arranged on the lower walls of the plurality of groups of inserts (11) except the lowermost group. The upper and lower adjacent groups of the plurality of groups of inserts (11) are positioned and connected via the positioning rings (17) and the positioning grooves (18).

7. The polylactic acid fiber spinneret with double concave-convex special-shaped cross section according to claim 6, characterized in that: The incremental size of each layer of the spinneret holes (12) is one fiftieth of the inner cavity size of the upper layer of the spinneret holes (12), and the lower edges of the plurality of groups of the spinneret holes (12) are all provided with arc chamfers (16).

8. The polylactic acid fiber spinneret with double concave-convex special-shaped cross section according to claim 7, characterized in that: The seat ring (3) is arranged on the upper wall of the upper plate (1), the liquid guide cavity (4) is arranged on the upper wall of the seat ring (3), the liquid guide groove (5) is arranged on the inner lower wall of the liquid guide cavity (4), the liquid guide hole (6) is arranged on the inner lower wall of the liquid guide groove (5), and the lower end of the liquid guide hole (6) is connected to the lower wall of the upper plate (1).

9. The polylactic acid fiber spinneret with double concave-convex special-shaped cross section according to claim 8, characterized in that: The inner wall of the lower plate (2) is provided with a first liquid inlet (202) for penetrating the sink (201) and the upper wall of the lower plate (2); the upper wall of the mounting seat (8) is provided with a second liquid inlet (802) penetrating the first liquid inlet (202) vertically; the upper wall of the insert sleeve (9) is provided with a third liquid inlet (902) penetrating the second liquid inlet (802) vertically; and the spinneret hole (12) is in communication with the third liquid inlet (902).

10. The polylactic acid fiber spinneret with double concave-convex special-shaped cross section according to claim 9, characterized in that: The coating structure is a nano alloy ion layer (15), and the nano alloy ion layer (15) is arranged on the inner wall of the spinneret hole (12).

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