CN211814727U

CN211814727U - Coagulation bath for wet spinning

Info

Publication number: CN211814727U
Application number: CN201921794360.8U
Authority: CN
Inventors: 王贺团; 沈志刚; 张静; 赵微微
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2019-10-24
Filing date: 2019-10-24
Publication date: 2020-10-30
Anticipated expiration: 2029-10-24

Abstract

The utility model relates to a coagulating bath groove for wet spinning, which mainly solves the problems of the prior art that the guide roll twines the filaments in the coagulating bath groove and the broken filaments in the overflow groove are more. By employing a coagulation bath for wet spinning comprising: comprises a gooseneck, a fairing plate, a spinning nozzle, a fairing A, a guide roll, a fairing B, an overflow plate and a main tank body; the rectifying plate is arranged on the left side in the main body groove body; the overflow plate is arranged on the right side in the main tank body; the gooseneck is arranged at the left end of the main body groove body, one end of the gooseneck, which is connected with the spinneret, is positioned at the right side of the rectifying plate, and the spinneret is covered with a rectifying cover A provided with a wire feeding channel; the fairing B is arranged on the right side of the main body groove body and can be partially positioned above a solidified liquid level, and the technical scheme of a filament moving channel is arranged in the fairing B, so that the problem is well solved, and the fairing B can be used for the wet spinning production of polyacrylonitrile-based carbon fiber protofilaments.

Description

Coagulation bath for wet spinning

Technical Field

The utility model relates to a wet spinning equipment for producing polyacrylonitrile raw silk for carbon fiber, in particular to a coagulating bath tank for realizing a coagulating process.

Background

PAN-based carbon fibers are a synthetic inorganic fiber. It is a fibrous polymer obtained by a series of processes of polymerization, spinning, preoxidation, carbonization and the like on acrylonitrile and comonomer. PAN molecules mainly undergo physical changes in the spinning process to form white fibrous protofilaments, the PAN protofilaments gradually change into a certain heat-resistant oxygen-containing structure in the pre-oxidation process, and carbon fibers with extremely high carbon content are obtained after carbonization. The carbon fiber has high specific strength, high specific modulus, high temperature resistance, chemical corrosion resistance and other performances, so that the carbon fiber has wide application fields.

The high-quality PAN precursor is the first necessary condition for manufacturing the high-performance carbon fiber and is one of the most critical factors influencing the quality of the carbon fiber. The production of high-quality PAN protofilaments puts high requirements on spinning equipment and processes, and especially the requirements on process parameters are particularly severe. In the spinning process, the solidification process is an important process for forming a fiber structure, and the structures of the primary fibers generated under different solidification conditions are different. The PAN solution wet spinning solidification forming process is a key step for generating micropores in the fiber, so that the spinning solidification condition has a decisive influence on the performance of the carbon fiber. In addition to micropores, an unreasonable coagulation process during spinning is also one of the key factors that contribute to the unevenness of the as-spun fibers. The coagulation technological parameters of wet spinning include coagulation bath temperature, concentration, negative drafting, etc.

In the traditional process of producing PAN protofilament by wet spinning, a coagulation bath mainly comprises a main body groove body, a distribution plate and an overflow plate. When the solidification process is unreasonable, the formed nascent fiber is broken under the disturbance action of a solidification liquid flow field; the freshly formed nascent fiber is also prone to filament breakage under the tensile stretching action of tension in a coagulation bath; after the coagulated fiber leaves the coagulation bath, the coagulated fiber enters the air atmosphere from the liquid environment, and the yarn breakage of the coagulated fiber is easily caused by the combined action of the temperature difference and the tension. These different causes cause the coagulated filaments to be partially or completely broken. The partially broken filaments are wound around the guide roll, and the completely broken filaments are brought to the overflow port of the coagulating liquid along with the flow of the coagulating liquid, so that a large number of broken filaments are collected after being accumulated in the overflow port of the coagulating bath for a certain period of time. The broken filaments are an important defect of the nascent fibers, and are inherited, so that the number of the broken filaments of the protofilament is increased, the breakage rate is increased, and the CV value is increased.

A coagulating bath groove for wet spinning introduces a fairing, reduces the influence of a flow field and temperature difference on broken filaments; the adjustment of the guide roller in the height direction and the active and passive power adjustment are added, and the influence of a tension field on the broken wire is overcome; eliminating the phenomena of wire winding of the guide roll in the coagulation bath and more broken wires in the overflow groove.

Patent CN201410430911.8 introduces a wet spinning coagulating bath groove, the invention relates to synthetic fiber wet spinning coagulating forming equipment, in particular to a wet spinning coagulating bath groove of Polyacrylonitrile (PAN) base carbon fiber precursor, which comprises three parts of a bath solution inlet buffer zone, a channel zone and a bath solution outlet collecting zone according to the traveling direction of tows, and is characterized in that: the invention has the beneficial effects that the concentration difference of the upper layer and the lower layer of bath lotion can be effectively reduced, the uniform formation of each part of a filament bundle is realized, and the dispersion among filaments of the filament bundle is reduced.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that the guide roll twines the silk and the overflow launder is broken silk in the coagulating bath that exist among the prior art is many. The coagulating bath for wet spinning is provided, and has the advantages that a fairing is introduced, so that the influence of a flow field and a temperature difference on broken filaments is reduced; the adjustment of the guide roller in the height direction and the active and passive power adjustment are added, and the influence of a tension field on the broken wire is overcome; eliminating the phenomena of wire winding of the guide roll in the coagulation bath and more broken wires in the overflow groove.

For solving the technical problem, the utility model discloses the technical scheme who adopts as follows: a coagulating bath for wet spinning comprises a gooseneck 3, a rectifying plate 4, a spinneret 5, a rectifying cover A6, a guide roller 7, a rectifying cover B8, an overflow plate 9 and a main body groove body 11; wherein, the rectifying plate 4 is arranged at the left side in the main body groove body 11; the overflow plate 9 is arranged at the right side in the main body groove body 11; the gooseneck 3 is arranged at the left end of the main body groove body, one end of the gooseneck connected with the spinning nozzle 5 is positioned at the right side of the rectifying plate 4, and the spinning nozzle is covered with a rectifying cover A6 provided with a yarn feeding channel; the fairing B8 is arranged on the right side of the main body groove body 11 and can be partially positioned above a solidification liquid level, a wire moving channel is arranged in the fairing B, and the guide roller 7 is used for guiding a wire moving channel entering the fairing B or guiding a wire moving channel entering the fairing B to leave the fairing B.

In the above technical solution, "left side", "right side" are based on the description shown in fig. 1 and fig. 2 of the present invention, or from left to right along the wire moving direction, and should not be understood as an absolute limitation of the present invention.

In the technical scheme, the fairing A6 is preferably of an axisymmetric structure, one end of the fairing A is hermetically connected with the gooseneck 3 connected with the spinneret or the spinneret, and the other end of the fairing A is opened for filament discharge; further preferably: the section shape of the fairing A6 is the same as that of the spinneret, and the symmetry axis is parallel to the filament outlet direction.

In the technical scheme, the wall surface around the fairing A6 is preferably provided with small holes for liquid diffusion.

In the above technical scheme, the gooseneck can be suspended and fixed or supported and fixed, and further preferred: the coagulating bath preferably further comprises a rotating shaft 1 and a bolt 2; the gooseneck 3 is movably fixed by a rotating shaft 1 and is supported by a bolt 2 arranged on the main body groove body.

In the technical scheme, the rotating angle of the gooseneck 3 around the rotating shaft 1 in the vertical plane is preferably less than 180 degrees; more preferably 0 to 120 °, and still more preferably greater than 0 °.

In the technical scheme, the height of the gooseneck 3 can be preferably adjusted by the bolts 2, and the height of the gooseneck 3 is mainly used for adjusting the height of the spinneret 4 and the direction of the spinneret.

In the above technical scheme, the included angle between the filament outlet direction of the spinneret 4 and the horizontal direction is preferably adjusted within the range of 0-10 degrees through the bolt 2 and the rotating shaft 1, more preferably within the range of 0-5 degrees, and still more preferably greater than 0 degrees.

In the above technical solution, the coagulation bath for wet spinning may further preferably include a crimping roller 10 for guiding the running filament to the next step.

In the technical scheme, the height of the guide roller 7 is preferably adjustable, so that the guide roller 7 can be completely positioned below the solidification liquid level or partially positioned above the solidification liquid level or completely positioned above the solidification liquid level; further preferably: when the guide roller 7 is completely positioned below the solidification liquid level or partially positioned above the solidification liquid level, the guide roller 7 is a driven roller; when the guide roller 7 is completely positioned above the solidification liquid level, the guide roller 7 is a driving roller, and the linear velocity of the surface of the guide roller 7 is the same as that of the surface of the curling roller; more preferably: the plane of the connecting line of the lower edge of the guide roller 7 and the center of the spinneret is vertical to the surface of the spinneret.

In the above technical solution, the fairing B8 is preferably a hollow cylinder, two ends of which are open for wire feeding, and an axial line of the fairing is parallel to a wire feeding direction.

The utility model has the advantages that through the specially designed coagulating bath tank, the coagulating bath tank is provided with the introduced fairing, thereby reducing the influence of the flow field and the temperature difference on the broken filaments; the adjustment of the guide roller in the height direction and the active and passive power adjustment are added, and the influence of a tension field on the broken wire is overcome; eliminating the phenomena of wire winding of the guide roll in the coagulation bath and more broken wires in the overflow groove.

By adopting the technical scheme of the utility model, the coagulating bath for wet spinning can be used in the wet spinning process of producing polyacrylonitrile protofilament for carbon fiber, thereby ensuring that the influence of a flow field and a temperature difference on broken filaments is reduced, and overcoming the influence of a tension field on the broken filaments; eliminates the phenomena of wire winding of the guide roll in the coagulation bath and more broken wires in the overflow groove, and obtains better technical effect.

Drawings

Fig. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural view of the present invention (spinning nozzle is raised by 5 °);

FIG. 3 is a schematic structural diagram of a comparative example employed in the present invention;

in fig. 1, 1 is a rotating shaft; 2 is a bolt; 3 is a gooseneck; 4 is a rectifying plate; 5 is a spinning nozzle; 6 is a fairing A; 7 is a guide roller; 8 is a fairing B; 9 is an overflow plate; 10 is a crimping roller; the main body groove body 11.

This is further illustrated by the following specific examples.

Detailed Description

[ example 1 ]

A coagulating bath tank: using and adjusting bolts to enable an included angle between a filament outlet direction of the spinneret and the horizontal direction to be 3 degrees in a two-dimensional plane; raising the nascent fiber in the horizontal direction for 3 degrees, and adjusting the height of the guide roller to ensure that the nascent fiber is partially immersed in the solidification liquid; raising the nascent fiber in the coagulating bath tank for 3 degrees in the horizontal direction; and a connecting line between the lower edge of the guide roller and the center of the spinneret is always vertical to the surface of the spinneret in a two-dimensional plane, the guide roller is a driven roller, a fairing A and a fairing B are used, no yarn is wound on the guide roller and the crimping roller after spinning for 24 hours, the dropped fibers are collected in the coagulation bath overflow tank, and the dropped fibers are subjected to solvent removal and drying to obtain the dropped fibers with the mass of 0.2677 g.

[ example 2 ]

A coagulating bath tank: using and adjusting bolts to enable an included angle between a filament outlet direction of the spinneret and the horizontal direction to be 5 degrees in a two-dimensional plane; the nascent fiber is lifted for 5 degrees in the horizontal direction, and the height of the guide roller is adjusted to be completely positioned above the liquid level of the solidification liquid; raising the nascent fiber in the coagulating bath tank for 5 degrees in the horizontal direction; the lower edge of the guide roller is connected with the center of the spinning nozzle in a two-dimensional plane and is always vertical to the surface of the spinning nozzle, the guide roller is a driving roller, the linear speed of the surface of the guide roller is the same as that of the surface of the curling roller, a fairing A and a fairing B are used, after 24 hours of spinning, no filament is wound on the guide roller and the curling roller, the dropped fibers are collected in the coagulation bath overflow groove, and after the solvent is removed and the fibers are dried, the dropped fibers have the mass of 0.1557 g.

[ example 3 ]

A coagulating bath tank: using and adjusting bolts to enable an included angle between a filament outlet direction of the spinneret and the horizontal direction to be 0 degree in a two-dimensional plane; keeping the direction of the nascent fiber horizontal, and adjusting the height of the guide roller to ensure that the nascent fiber is completely immersed in the solidification liquid; the direction of the nascent fiber in the coagulating bath tank is horizontal; and a connecting line between the lower edge of the guide roller and the center of the spinneret is always vertical to the surface of the spinneret in a two-dimensional plane, the guide roller is a driven roller, a fairing A and a fairing B are used, no yarn is wound on the guide roller and the crimping roller after spinning for 24 hours, the dropped fibers are collected in the coagulation bath overflow tank, and the dropped fibers are subjected to solvent removal and drying to obtain the dropped fibers with the mass of 0.3112 g.

[ example 4 ]

A coagulating bath tank: using and adjusting bolts to enable an included angle between a filament outlet direction of the spinneret and the horizontal direction to be 4 degrees in a two-dimensional plane; the nascent fiber is lifted for 4 degrees in the horizontal direction, and the height of the guide roller is adjusted to be completely positioned above the solidification liquid; raising the nascent fiber in the coagulating bath tank for 4 degrees in the horizontal direction; the lower edge of the guide roller is connected with the center of the spinning nozzle in a two-dimensional plane and is always vertical to the surface of the spinning nozzle, the guide roller is a driving roller, the linear speed of the surface of the guide roller is the same as that of the surface of the curling roller, a fairing A and a fairing B are used, after 24 hours of spinning, no filament is wound on the guide roller and the curling roller, the dropped fibers are collected in the coagulation bath overflow groove, and after the solvent is removed and the fibers are dried, the dropped fibers have the mass of 0.1733 g.

[ example 5 ]

A coagulating bath tank: using and adjusting bolts to enable an included angle between a filament outlet direction of the spinneret and the horizontal direction to be 1 degree in a two-dimensional plane; raising the nascent fiber in the horizontal direction by 1 degree, and adjusting the height of the guide roller to ensure that the nascent fiber is completely positioned in the solidification liquid; raising the nascent fiber in the coagulating bath tank for 1 degree in the horizontal direction; and a connecting line between the lower edge of the guide roller and the center of the spinneret is always vertical to the surface of the spinneret in a two-dimensional plane, the guide roller is a driven roller, a fairing A and a fairing B are used, no yarn is wound on the guide roller and the crimping roller after spinning for 24 hours, the dropped fibers are collected in the coagulation bath overflow tank, and the dropped fibers are subjected to solvent removal and drying to obtain the dropped fibers with the mass of 0.1254 g.

[ example 6 ]

A coagulating bath tank: using and adjusting bolts to enable an included angle between a filament outlet direction of the spinneret and the horizontal direction to be 2 degrees in a two-dimensional plane; raising the nascent fiber in the horizontal direction for 2 degrees, and adjusting the height of the guide roller to ensure that the nascent fiber is partially immersed in the solidification liquid; raising the nascent fiber in the coagulating bath tank for 2 degrees in the horizontal direction; and a connecting line between the lower edge of the guide roller and the center of the spinneret is always vertical to the surface of the spinneret in a two-dimensional plane, the guide roller is a driven roller, a fairing A and a fairing B are used, no yarn is wound on the guide roller and the crimping roller after spinning for 24 hours, the dropped fibers are collected in the coagulation bath overflow tank, and the dropped fibers are subjected to solvent removal and drying to obtain the dropped fibers with the mass of 0.4225 g.

[ COMPARATIVE EXAMPLE 1 ]

A coagulating bath tank: the structural schematic diagram of the coagulating bath is shown in figure 3, the height of the guide roller is adjusted without using the adjusting bolt 2, so that the guide roller is partially immersed in the coagulating liquid; raising the direction of the nascent fiber in the coagulating bath tank by 3 degrees in the horizontal direction; the guide roll is a driven roll, a fairing A and a fairing B are not used, a large number of fiber winding rolls are arranged on the guide roll and the crimping roll after spinning for 24 hours, dropped fibers are collected in the coagulation bath overflow groove, and the dropped fibers are 3.3578g in mass after solvent removal and drying.

It can be seen from comparative example 1 and example 1 that, after the coagulating bath of the utility model is adopted, the influence of the flow field and the temperature difference on the broken filaments can be ensured to be reduced, the influence of the tension field on the broken filaments can be overcome, and the phenomena of filament winding of the godet roller in the coagulating bath and much broken filaments in the overflow groove can be eliminated.

Claims

1. A coagulating bath for wet spinning comprises a gooseneck (3), a rectifying plate (4), a spinning nozzle (5), a rectifying cover A (6), a guide roller (7), a rectifying cover B (8), an overflow plate (9) and a main body groove body (11); wherein, the rectifying plate (4) is arranged at the left side in the main body groove body (11); the overflow plate (9) is arranged on the right side in the main body groove body (11); the gooseneck (3) is arranged at the left end of the main body groove body, one end of the gooseneck, which is connected with the spinning nozzle (5), is positioned at the right side of the rectifying plate (4), and the spinning nozzle is covered with a rectifying cover A (6) provided with a wire feeding channel; the fairing B (8) is arranged on the right side of the main body groove body (11) and can be partially positioned above a solidification liquid level, a wire moving channel is arranged in the fairing B, and the guide roller (7) is used for guiding wire moving to enter the wire moving channel in the fairing B or guiding the wire moving entering the fairing B to leave the fairing B.

2. Coagulation bath for wet spinning according to claim 1, characterized in that the fairing a (6) is of axisymmetric structure, one end is hermetically connected to the gooseneck (3) or spinneret connected to the spinneret, and the other end is open for filament discharge.

3. Coagulation bath for wet spinning according to claim 2, characterized in that the fairing a (6) has the same cross-sectional shape as the spinneret, the symmetry axis being parallel to the direction of filament emergence.

4. The coagulation bath for wet spinning according to claim 2, wherein the fairing A (6) has small holes on its peripheral wall surface.

5. Coagulation bath for wet spinning according to claim 1, characterized in that it further comprises a rotating shaft (1), a bolt (2); the gooseneck (3) is movably fixed by the rotating shaft (1) and is supported by a bolt (2) arranged on the main body groove body.

6. Coagulation bath for wet spinning according to claim 5, characterized in that the angle of rotation of the gooseneck (3) in the vertical plane about the axis of rotation (1) is less than 180 °.

7. Coagulation bath for wet spinning according to claim 5, characterized in that the height of the gooseneck (3) is adjustable by means of bolts (2).

8. The coagulation bath for wet spinning according to claim 5, wherein the angle between the filament outlet direction of the spinneret (5) and the horizontal direction is adjusted within the range of 0-10 ° by the bolt (2) and the rotating shaft (1).

9. Coagulation bath for wet spinning according to claim 1, characterized in that the height of the guiding roll (7) is adjustable such that the guiding roll (7) is completely below or partially above or completely above the coagulation level.

10. Coagulation bath for wet spinning according to claim 9, characterized in that the guiding roll (7) is a passive roll when the guiding roll (7) is completely below or partially above the coagulation level.

11. Coagulation bath for wet spinning according to claim 9, characterized in that the guide roll (7) is a driving roll when the guide roll (7) is completely above the coagulation level and the linear velocity of the surface of the guide roll (7) is the same as the linear velocity of the surface of the crimping roll.

12. Coagulation bath for wet spinning according to claim 1, characterized in that the plane of the lower edge of the guide roll (7) connecting the center of the spinneret is perpendicular to the surface of the spinneret; the fairing B (8) is in a hollow cylindrical shape, two ends of the fairing B are opened for wire feeding, and the axial line of the fairing is parallel to the wire feeding direction.