Device and method for preparing carbon fiber flat yarn precursor

Abstract

The present application discloses a device and method for preparing carbon fiber flat yarn precursor, the equipment device includes: a spinning mechanism and a coagulation mechanism, wherein: the spinning mechanism is used to provide polyacrylonitrile spinning solution and has a straight-line spinneret; the coagulation mechanism includes a coagulation bath and a calendering unit; the coagulation bath is used to contain the coagulation liquid, and when in use, the polyacrylonitrile spinning solution is ejected through the spinneret, enters the coagulation liquid and is formed into polyacrylonitrile coagulated filaments; the calendering unit is used to apply pressure to the polyacrylonitrile coagulated filaments to obtain carbon fiber flat yarn precursor. By using the device or method for preparing carbon fiber flat yarn precursor of the present application, noodle-shaped carbon fiber flat yarn precursor can be prepared, and carbon fiber flat yarn can be obtained through subsequent processing, which can eliminate process links such as weaving and pre-preg, improve production efficiency, reduce production costs, and is conducive to the application of carbon fiber yarn in high-impact and high-temperature use scenarios.

Description

Technical Field

[0001] The present application relates to the field of carbon fiber precursor production technology, and in particular to a device and method for preparing carbon fiber flat precursor. Background Art

[0002] Carbon fiber is a fibrous polymer material with a carbon content exceeding 90%. It possesses excellent properties such as high strength, high modulus, strong corrosion resistance, and resistance to thermal expansion. It is widely used in aerospace, defense, automotive, and sporting goods industries. The carbon fiber manufacturing process primarily involves polymerization, spinning, and carbonization. The product obtained from the spinning step is called carbon fiber precursor, and the morphology of the carbon fiber precursor ultimately determines the morphology of the carbon fiber.

[0003] In existing spinning technologies, carbon fiber precursor is usually spun by wet spinning or dry-jet wet spinning. In the wet spinning method, the spinning solution is ejected from the spinneret and directly enters the coagulation bath to solidify and form, that is, double diffusion and phase separation occur to form nascent silk; in the dry-wet spinning method, the spinning solution is sprayed through the spinneret, passes through the dry section air layer, and then runs into the coagulation bath to solidify and form. After solidification and forming, it is usually pulled and stretched by one or more traction rollers, and then washed, dried, oiled, and collected to obtain carbon fiber precursor. However, the carbon fiber precursors currently produced are all linear filaments with a roughly circular cross-section. In subsequent applications, it is usually necessary to go through processes such as weaving and prepreg to bond the carbon fiber filaments to each other to obtain carbon fiber products that meet application requirements. In this case, the strength of the carbon fiber product is related to the bonding strength between the carbon fiber filaments and the high temperature resistance of the adhesive in addition to the performance of the carbon fiber filaments themselves. Typically, the adhesive used between carbon fiber filaments is epoxy resin, and the mechanical properties of epoxy resin are significantly different from those of carbon fiber itself. Therefore, the strength between carbon fiber filaments is much worse than the strength of the carbon fiber filaments themselves. In some applications where high impact resistance, pressure resistance, and heat resistance are required, the strength of carbon fiber products may not meet the requirements. For example, during a dive, a carbon fiber submersible may break due to the excessive pressure resistance of the epoxy resin in the carbon fiber filaments, leading to the collapse of the entire submersible. For example, a tank with carbon fiber prepreg on the top may decompose the epoxy resin in the high-temperature environment of an explosion, causing the protective effect of the carbon fiber cloth to be lost.

[0004] In summary, the current carbon fiber precursors and carbon fiber products cannot meet specific application scenarios, which makes the application of carbon fiber have great limitations. Summary of the Invention

[0005] The purpose of this application is to provide a device and method for preparing carbon fiber flat yarn precursor.

[0006] This application adopts the following technical solutions:

[0007] One aspect of the present application discloses a device for preparing carbon fiber flat yarn precursor, which includes a spinning mechanism and a coagulation mechanism, wherein: the spinning mechanism is used to provide polyacrylonitrile spinning stock solution and has a straight-line spinneret; the coagulation mechanism includes a coagulation bath and a calendering section; the coagulation bath is used to contain the coagulation liquid, and when in use, the polyacrylonitrile spinning stock solution is ejected through the spinneret, enters the coagulation liquid and is formed into polyacrylonitrile coagulation filaments; the calendering section is used to apply pressure to the polyacrylonitrile coagulation filaments to obtain the carbon fiber flat yarn precursor.

[0008] It should be noted that the preparation device of the carbon fiber flat yarn precursor of the present application has a spinneret in a straight line shape, which is conducive to providing noodle-shaped polyacrylonitrile spinning solution to the coagulation liquid, and forming noodle-shaped polyacrylonitrile coagulation filaments after entering the coagulation liquid, and then through the action of the calendering part, the solvent in the polyacrylonitrile coagulation filaments is further discharged, which is conducive to making the noodle-shaped carbon fiber flat yarn precursor smoother and thinner. In addition, the present application can adopt existing carbon fiber production processes and equipment, and only needs to be equipped with a special spinneret and calendering mechanism, and the preparation process is simple; the shape of the prepared carbon fiber is a flat yarn (it can be understood that "flat yarn" refers to the shape of the cross section of the carbon fiber yarn is flat and straight, corresponding to the "round yarn" in the prior art), which can eliminate the process links such as weaving and pre-preg, improve production efficiency, and reduce production costs; and the carbon fiber flat yarn prepared in the present application, when the carbon fiber flat yarn obtained by subsequent processing is applied to high impact, high temperature and other use scenarios, has excellent properties of high strength and high modulus, and is of great strategic significance.

[0009] In one implementation of the present application, the carbon fiber flat yarn precursor prepared by the present application and the carbon fiber flat yarn obtained through subsequent processing do not need to be bonded with epoxy resin or pre-impregnated into cloth during subsequent applications, and can be directly covered on the surface of an object over a large area, thereby solving the strength and modulus problems of existing carbon fibers in special application fields.

[0010] In one implementation of the present application, the width of the spinneret is 10-200 cm. Preferably, the width of the spinneret is 30-120 cm. Thus, it is possible to facilitate the preparation of carbon fiber flat filament precursors of relatively large width. In this case, in subsequent applications, the surface of an object can be directly covered over a large area without the need for epoxy resin bonding treatment or pre-preg.

[0011] In one implementation of the present application, the number of the calendering sections is one or more. In this case, the polyacrylonitrile coagulated filaments can be pressed once or multiple times, which is conducive to gradually draining the solvent inside the polyacrylonitrile coagulated filaments, making the carbon fiber flat filaments smoother and thinner.

[0012] In one implementation of the present application, the pressure between the first pressing roller and the second pressing roller is not less than 10 MPa. In this case, it is beneficial to make the prepared carbon fiber flat yarn have a thinner thickness.

[0013] In one embodiment of the present application, the coagulation mechanism further includes a guide portion, which is disposed between the spinneret and the calendering portion and is configured to guide the polyacrylonitrile coagulated filaments to the calendering portion. Thus, the coagulated polyacrylonitrile coagulated filaments can be guided to the calendering portion for pressure and stretching by the guide portion.

[0014] In one implementation of the present application, the device for preparing the carbon fiber flat yarn precursor also includes an air supply mechanism, which is used to apply ethylene and / or propylene gas to the polyacrylonitrile spinning stock solution ejected from the spinneret, so that the polyacrylonitrile spinning stock solution ejected from the spinneret forms a film on its surface before entering the coagulation liquid, and adsorbs ethylene and / or propylene on the surface of the film to form an adsorption layer. It can be understood that after the polyacrylonitrile spinning solution is ejected from the spinneret, the air supply mechanism introduces ethylene and / or propylene gas into the polyacrylonitrile spinning solution. On the one hand, the ethylene and / or propylene gas can help accelerate the volatilization of the solvent in the polyacrylonitrile spinning solution, so that a film is formed on the surface of the polyacrylonitrile spinning solution. On the other hand, the film can adsorb ethylene and / or propylene gas to form an adsorption layer. The adsorption layer can enhance the strength of the carbon fiber flat yarn precursor, that is, enhance the strength of the carbon fiber flat yarn precursor during the preparation process, and play a key role in the subsequent stretching and thinning (calendering) of the polyacrylonitrile coagulation filament; in addition, in the subsequent carbonization process, the adsorption layer can also react with the polyacrylonitrile in the carbon fiber precursor to form a dense amorphous carbon layer, further improving the modulus and strength of the carbon fiber.

[0015] In one implementation of the present application, the gas supply mechanism includes a sleeve arranged on the spinneret, and the sleeve is arranged between the spinneret and the coagulation bath of the coagulation mechanism, and is used to accommodate the introduction of ethylene and / or propylene gas; when in use, the polyacrylonitrile spinning solution ejected from the spinneret first enters the sleeve, contacts with ethylene and / or propylene gas, and then enters the coagulation liquid in the coagulation bath after passing through the sleeve.

[0016] In one implementation of the present application, the carbon fiber flat yarn production apparatus further includes a discharge mechanism configured to discharge the coagulation liquid from the carbon fiber flat yarn. In this case, the discharge mechanism can discharge the coagulation liquid from the carbon fiber flat yarn obtained by coagulation and calendering, thereby facilitating subsequent processes on the carbon fiber flat yarn, such as washing, drying, oiling, and winding.

[0017] In one implementation of the present application, the carbon fiber flat yarn production apparatus further comprises one or more of a washing mechanism, a drying mechanism, an oiling mechanism, and a wire collecting mechanism. In this case, the carbon fiber flat yarn can be processed by one or more of the washing mechanism, the drying mechanism, the oiling mechanism, and the wire collecting mechanism. It should be noted that the devices required for the washing, drying, oiling, and wire collecting processes can refer to existing technologies.

[0018] In one implementation of the present application, the width of the carbon fiber flat yarn precursor is 10-200 cm, and the thickness of the carbon fiber flat yarn precursor is 5-15 μm.

[0019] In one implementation of the present application, the width of the carbon fiber flat yarn precursor is 30-120 cm, and the thickness of the carbon fiber flat yarn precursor is 5-10 μm.

[0020] Another aspect of the present application discloses a method for preparing carbon fiber flat yarn precursor, which comprises contacting the polyacrylonitrile spinning stock solution ejected from the spinneret with ethylene and / or propylene gas to form a film on its surface, and adsorbing ethylene and / or propylene on the surface of the film to form an adsorption layer, and then contacting with a coagulation liquid, coagulating, and calendering to form the carbon fiber flat yarn precursor.

[0021] It should be noted that the preparation method of the present application, by introducing ethylene and / or propylene gas into the polyacrylonitrile spinning stock solution ejected from the spinneret, can form a film on the surface of the polyacrylonitrile spinning stock solution before entering the coagulation solution, and adsorb ethylene and / or propylene on the film surface to form an adsorption layer. Specifically, after the polyacrylonitrile spinning stock solution is ejected from the spinneret, the gas supply mechanism supplies ethylene and / or propylene gas to the polyacrylonitrile spinning stock solution. On the one hand, the ethylene and / or propylene gas can help accelerate the volatilization of the solvent in the polyacrylonitrile spinning stock solution, forming a film on the surface of the polyacrylonitrile spinning stock solution. On the other hand, the film can adsorb ethylene and / or propylene gas to form an adsorption layer. The adsorption layer can enhance the strength of the carbon fiber flat yarn, that is, it enhances the strength of the carbon fiber flat yarn during the preparation process, and plays a key role in the subsequent stretching and thinning (calendering) of the polyacrylonitrile coagulation filament; in addition, in the subsequent carbonization process, the adsorption layer can also react with the polyacrylonitrile in the carbon fiber precursor to form a dense amorphous carbon layer, further improving the modulus and strength of the carbon fiber.

[0022] In one implementation of the present application, the preparation method includes: a spinning step: the polyacrylonitrile spinning stock solution is ejected through a straight-line spinneret; a gas supply step: ethylene and / or propylene gas is applied to the polyacrylonitrile spinning stock solution ejected from the spinneret to form a film on the surface, and ethylene and / or propylene is adsorbed on the surface of the film to form an adsorption layer; a coagulation step: the ejected polyacrylonitrile spinning stock solution is allowed to enter the coagulation liquid to form the polyacrylonitrile spinning stock solution into a polyacrylonitrile coagulated filament; a calendering step: the polyacrylonitrile coagulated filament is pressurized in the coagulation liquid to obtain the carbon fiber flat filament.

[0023] It should be noted that the method for preparing the carbon fiber flat yarn precursor of the present application has a straight-line spinneret, which is conducive to providing noodle-shaped polyacrylonitrile spinning stock solution to the coagulation liquid, and forming noodle-shaped polyacrylonitrile coagulation filaments after entering the coagulation liquid. Subsequently, the polyacrylonitrile coagulation filaments are pressurized, which can further discharge the solvent in the polyacrylonitrile coagulation filaments, thereby facilitating the preparation of the noodle-shaped carbon fiber flat yarn precursor to be smoother and thinner. In addition, the preparation method of the present application can adopt existing carbon fiber production processes and equipment, and only needs to be equipped with a special spinneret and calendering mechanism, and the preparation process is simple; the shape of the prepared carbon fiber is flat, which can eliminate process links such as weaving and pre-preg, improve production efficiency, and reduce production costs; and the carbon fiber flat yarn precursor prepared by the present application has excellent properties of high strength and high modulus when used in high-impact, high-temperature and other usage scenarios, and has great strategic significance.

[0024] In one implementation of the present application, the polyacrylonitrile coagulated filaments are pressurized once or multiple times during the calendering step. In this case, the polyacrylonitrile coagulated filaments can be pressurized once or multiple times, which is conducive to gradually expelling the solvent inside the polyacrylonitrile coagulated filaments, making the carbon fiber flat filaments smoother and thinner.

[0025] In one implementation of the present application, in the calendering step, the pressure applied to the polyacrylonitrile coagulated filaments is not less than 10 MPa. In this case, it is advantageous for the prepared carbon fiber flat filaments to have a thinner thickness.

[0026] In one implementation of the present application, the volume fraction of ethylene and / or propylene is 30-90%.

[0027] In one implementation of the present application, the polyacrylonitrile spinning solution is obtained by dissolving polyacrylonitrile in a solvent, and the solvent is dimethylformamide or dimethyl sulfoxide.

[0028] In one implementation of the present application, in the polyacrylonitrile spinning solution, the mass fraction of polyacrylonitrile is 10-30%.

[0029] In one implementation of the present application, in the polyacrylonitrile spinning solution, the mass fraction of polyacrylonitrile is 17-26%.

[0030] In one implementation of the present application, the width of the carbon fiber flat yarn precursor is 10-200 cm, and the thickness of the carbon fiber flat yarn precursor is 5-15 μm.

[0031] In one implementation of the present application, the width of the carbon fiber flat yarn precursor is 30-120 cm, and the thickness of the carbon fiber flat yarn precursor is 5-10 μm.

[0032] In one implementation of the present application, after the calendering step, the step of allowing the carbon fiber flat filaments to be discharged from the coagulation liquid is further included. In this case, allowing the carbon fiber flat filaments obtained by coagulation and calendering to be discharged from the coagulation liquid facilitates subsequent processing of the carbon fiber flat filaments, such as washing, drying, oiling, and winding. It should be noted that subsequent process steps such as washing, drying, oiling, and winding can refer to existing technologies.

[0033] In one implementation of the present application, after the carbon fiber flat yarn is led out of the coagulation liquid, the process further includes washing, drying, oiling, and collecting the carbon fiber flat yarn. It should be noted that the process steps of washing, drying, oiling, and collecting can refer to the existing technology.

[0034] Due to the adoption of the above technical solution, the beneficial effects of this application are:

[0035] The device for preparing the carbon fiber flat yarn precursor of the present application has a straight-line spinneret, which is conducive to providing noodle-shaped polyacrylonitrile spinning stock solution to the coagulation liquid, and forming noodle-shaped polyacrylonitrile coagulation filaments after entering the coagulation liquid, and then through the action of the guide part and the calendering part, the solvent in the polyacrylonitrile coagulation filaments is further discharged, which is conducive to making the noodle-shaped carbon fiber flat yarn precursor smoother and thinner. In addition, the present application can adopt the existing carbon fiber production process and equipment, and only needs to be equipped with a special spinneret and calendering mechanism, and the preparation process is simple; the carbon fiber prepared by subsequent carbonization and other processes is in the shape of a flat yarn, which can eliminate the process links such as weaving and pre-preg, improve production efficiency, and reduce production costs; and the carbon fiber flat yarn obtained by subsequent processing of the carbon fiber flat yarn precursor prepared by the present application has excellent properties of high strength and high modulus when used in high impact, high temperature and other usage scenarios, which is of great strategic significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of the device for preparing carbon fiber flat yarn precursor of the present application.

[0037] Description of reference numerals:

[0038] Preparation device...100, spinning mechanism...10, coagulation mechanism...20, air supply mechanism...30, spinneret...11, coagulation bath...21, guide part...22, calendering part...23, first pressing roller...231, second pressing roller...232, sleeve...31, polyacrylonitrile coagulation filament 800, carbon fiber flat yarn 900. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other materials or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid overwhelm the core of the present application with excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. The related operations can be fully understood based on the description in the specification and the general technical knowledge in the art.

[0040] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0041] Herein, the description of numerical ranges includes the endpoints as well as any number within the range, for example, "1-10" may include 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0042] The present embodiment relates to a production apparatus for carbon fiber flat yarn precursor (hereinafter sometimes referred to as “production apparatus 1 ”).

[0043] Figure 1 This is a schematic diagram of the structure of the device for preparing the carbon fiber flat yarn precursor of the present application, such as Figure 1 As shown, in one embodiment, the preparation device 1 may include a spinning mechanism 10 and a solidification mechanism 20 .

[0044] In one embodiment, the spinning mechanism 10 may include a spinneret 11 for providing polyacrylonitrile spinning solution.

[0045] In one embodiment, the polyacrylonitrile spinning solution can be obtained by dissolving polyacrylonitrile in a solvent, wherein the solvent can be dimethylformamide or dimethyl sulfoxide.

[0046] In one embodiment, the mass fraction of polyacrylonitrile in the polyacrylonitrile spinning solution may be 10-30%, preferably 17-26%.

[0047] In one embodiment, the spinneret 11 can be in a straight line shape. This allows the ejected polyacrylonitrile spinning solution to be shaped like noodles. It is understood that the "straight line" corresponds to the "round" spinneret in the prior art. The polyacrylonitrile spinning solution ejected from the "straight line" spinneret has a noodle-like shape. The "straight line" spinneret can also refer to a "long strip spinneret."

[0048] In one embodiment, the width of the spinneret 11 can be 10-200 cm. Thus, noodle-shaped polyacrylonitrile spinning solution with a width of 10-200 cm can be supplied to the coagulation mechanism 20. Preferably, the width of the spinneret 11 is 30-120 cm.

[0049] In one embodiment, the coagulation mechanism 20 is used to coagulate and shape the polyacrylonitrile spinning solution supplied from the spinneret 11 .

[0050] In one embodiment, the coagulation mechanism 20 may include a coagulation bath 21 , and the coagulation bath 21 may contain a coagulation liquid.

[0051] In one embodiment, the polyacrylonitrile spinning solution enters the coagulation solution and is formed into the polyacrylonitrile coagulated filaments 800 .

[0052] In one embodiment, the coagulation mechanism 20 may include a guide portion 22. The guide portion 22 is used to guide the polyacrylonitrile coagulated filaments 800.

[0053] In one embodiment, the guide portion 22 is disposed in the coagulation liquid.

[0054] In one embodiment, the guide portion 22 is disposed between the spinneret 11 and the calendering portion 23 .

[0055] In one embodiment, the guide portion 22 may be a roller structure.

[0056] In one embodiment, the solidification mechanism 20 may include a rolling portion 23 .

[0057] In one embodiment, the rolling portion 23 may be disposed in the coagulation liquid.

[0058] In one embodiment, the guide portion 22 can guide the polyacrylonitrile coagulated filaments 800 to the calendering portion 23 , and the calendering portion 23 can apply pressure to the polyacrylonitrile coagulated filaments 800 to obtain the carbon fiber flat filaments 900 .

[0059] In one embodiment, the calendering section 23 may include a first pressing roller 231 and a second pressing roller 232. Both the first pressing roller 231 and the second pressing roller 232 are roller structures. The polyacrylonitrile coagulated filaments 800 enter between the first pressing roller 231 and the second pressing roller 232, and the first pressing roller 231 and the second pressing roller 232 press the polyacrylonitrile coagulated filaments 800.

[0060] In one embodiment, the pressure between the first pressing roller 231 and the second pressing roller 232 is no less than 10 MPa.

[0061] In one embodiment, the number of the calendering portion 23 may be one or more.

[0062] In one embodiment, the preparation device 1 may further include a gas supply mechanism 30 .

[0063] In one embodiment, the gas supply mechanism 30 may supply ethylene and / or propylene gas to the polyacrylonitrile spinning solution supplied from the spinneret 11 .

[0064] In one embodiment, the volume fraction of ethylene and / or propylene is 30-90%, wherein the remaining 10%-70% of the gas may be air.

[0065] In one embodiment, the gas supply mechanism 30 may include a sleeve 31 sleeved on the spinneret 11, and ethylene and / or propylene gas may be passed through the sleeve 31. In this case, ethylene and / or propylene gas can be passed through the sleeve to the polyacrylonitrile spinning solution.

[0066] In one embodiment, sleeve 31 is positioned between spinneret 11 and the coagulating liquid level. In this case, after the polyacrylonitrile spinning solution is ejected from the spinneret and before it enters the coagulating liquid, it can contact the ethylene and / or propylene gas provided by the sleeve.

[0067] In one embodiment, the ventilation direction of the ethylene and / or propylene gas in the sleeve 31 is opposite to the direction in which the polyacrylonitrile spinning solution flows toward the coagulation solution.

[0068] In one embodiment, the width of the carbon fiber flat yarn 900 may be 10-200 cm. Preferably, the width of the carbon fiber flat yarn 900 is 30-120 cm.

[0069] In one embodiment, the thickness of the carbon fiber flat yarn 900 may be 5-15 microns. Preferably, the thickness of the carbon fiber flat yarn 900 is 5-10 microns.

[0070] In one embodiment, the preparation device 1 may further include a guide mechanism for guiding the carbon fiber flat yarn 900 out of the coagulation liquid.

[0071] In one embodiment, the preparation device 1 may further include a water washing mechanism.

[0072] In one embodiment, the preparation device 1 may further include a drying mechanism.

[0073] In one embodiment, the preparation device 1 may further include an oiling mechanism.

[0074] In one embodiment, the preparation device 1 may further include a wire collecting mechanism.

[0075] This embodiment also relates to a method for preparing carbon fiber flat yarn precursor (hereinafter sometimes referred to as "preparation method").

[0076] In one embodiment, the preparation method may include: contacting the polyacrylonitrile spinning stock solution ejected from the spinneret with ethylene and / or propylene gas to form a film on its surface, and adsorbing ethylene and / or propylene on the surface of the film to form an adsorption layer, and then contacting with a coagulation liquid, coagulating, and calendering to form the carbon fiber flat yarn.

[0077] In one embodiment, the preparation method may include: a spinning step: the polyacrylonitrile spinning stock solution is released through a straight-line spinneret 11; a coagulation step: the released polyacrylonitrile spinning stock solution is allowed to enter the coagulation liquid so that the polyacrylonitrile spinning stock solution is formed into a polyacrylonitrile coagulated filament 800; a calendering step: in the coagulation liquid, the polyacrylonitrile coagulated filament 800 is pressurized to obtain a carbon fiber flat filament 900.

[0078] In one embodiment, after the spinning step, a step of adding ethylene and / or propylene gas to the polyacrylonitrile spinning solution may be further included, followed by a coagulation step.

[0079] In one embodiment, the volume fraction of ethylene and / or propylene may be 30-90%.

[0080] In one embodiment, the ventilation direction of the ethylene and / or propylene gas is opposite to the flow direction of the polyacrylonitrile spinning solution toward the coagulation solution.

[0081] In one embodiment, during the calendering step, the carbon fiber coagulation filaments 800 may be pressed once or multiple times.

[0082] In one embodiment, in the calendering step, the pressure applied to the polyacrylonitrile coagulated filaments 800 is no less than 10 MPa.

[0083] In one embodiment, after the calendering step, the method further includes the step of leading the carbon fiber flat yarn 900 out of the coagulation liquid.

[0084] In one embodiment, after the carbon fiber flat yarn precursor 900 is led out of the coagulation liquid, the method further includes performing one or more steps of washing, drying, oiling, and collecting the carbon fiber flat yarn precursor 900.

[0085] The present invention will be further described below with reference to specific examples. It should be understood that the examples are merely illustrative and do not limit the scope of protection of the present invention.

[0086] Example 1

[0087] Polyacrylonitrile (PAN) is dissolved in dimethylformamide (DMF) to a mass percentage of 26%. The material is placed in a dissolution vessel, heated to 70°C, and stirred continuously for 48 hours. The material is then pumped into a degassing vessel and degassed under vacuum for 72 hours. A centrifugal pump then pumps the material into a 30cm wide, I-shaped spinneret, which produces flat yarns. Ethylene gas (85% by volume) is introduced axially upward through a sleeve connected to the spinneret, accelerating solvent evaporation while forming a film on the surface of the flat yarns. The flat yarns then enter the coagulation liquid in the coagulation mechanism and are guided by guide rollers to counterrollers, which apply pressure and stretch the yarns at a pressure of 12 MPa. The resulting ultra-wide flat carbon fiber precursor yarns are 30 cm wide and 15 microns thick. Tensile testing reveals a tensile strength of 11.7 cm / dtex, demonstrating excellent strength and modulus.

[0088] Example 2

[0089] Polyacrylonitrile (PAN) is dissolved in dimethyl sulfoxide (DMSO) to a mass percentage of 22%. The material is placed in a dissolution vessel, heated to 70°C, and stirred continuously for 48 hours. The material is then pumped into a degassing vessel and degassed under vacuum for 72 hours. A centrifugal pump then pumps the material into a 30cm wide, I-shaped spinneret, where flat yarns are produced. Propylene gas (85% by volume) is introduced axially upward through a sleeve connected to the spinneret, accelerating solvent evaporation while forming a film on the surface of the flat yarns. The flat yarns then enter the coagulation liquid in the coagulation mechanism and are guided by guide rollers to counterrollers, which apply pressure and stretch the yarns at a pressure of 11 MPa. The resulting ultra-wide flat carbon fiber precursor yarns are 30 cm wide and 15 microns thick. Tensile testing reveals a tensile strength of 10.1 cn / dtex, demonstrating excellent strength and modulus.

[0090] The above content is a further detailed description of the present application in conjunction with specific implementation methods, and the specific implementation of the present application cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A device for preparing carbon fiber flat yarn precursor, characterized in that: The device for preparing the carbon fiber flat yarn precursor comprises a spinning mechanism, an air supply mechanism and a coagulation mechanism, wherein: The spinning mechanism is used to provide polyacrylonitrile spinning solution and has a straight-shaped spinning head; The gas supply mechanism is used to apply ethylene and / or propylene gas to the polyacrylonitrile spinning stock solution ejected from the spinneret, so that the polyacrylonitrile spinning stock solution ejected from the spinneret forms a film on its surface before entering the coagulation liquid, and ethylene and / or propylene are adsorbed on the surface of the film to form an adsorption layer; The coagulation mechanism includes a coagulation bath and a calendering section; the coagulation bath is used to contain a coagulation liquid. When in use, the polyacrylonitrile spinning solution is ejected through the spinneret, enters the coagulation liquid and is formed into a polyacrylonitrile coagulated filament; the calendering section is used to apply pressure to the polyacrylonitrile coagulated filament to obtain the carbon fiber flat filament; The calendering section includes a first pressing roller and a second pressing roller arranged adjacent to each other, the polyacrylonitrile coagulated filaments enter between the first pressing roller and the second pressing roller, and pressure is applied to the polyacrylonitrile coagulated filaments by the first pressing roller and the second pressing roller; the pressure between the first pressing roller and the second pressing roller is not less than 10 MPa; The width of the carbon fiber flat yarn precursor is 10-200 cm, and the thickness of the carbon fiber flat yarn precursor is 5-15 μm.

2. The preparation device according to claim 1, characterized in that The number of the calendering parts is one or more.

3. The preparation device according to claim 1, characterized in that The coagulation mechanism further includes a guide portion, which is arranged between the spinneret and the calendering portion and is used to guide the polyacrylonitrile coagulated filaments to the calendering portion.

4. The preparation device according to claim 1, characterized in that The gas supply mechanism includes a sleeve mounted on the spinneret, and the sleeve is arranged between the spinneret and the coagulation bath of the coagulation mechanism, and is used to introduce ethylene and / or propylene gas; when in use, the polyacrylonitrile spinning stock solution ejected from the spinneret first enters the sleeve, contacts with ethylene and / or propylene gas, and then enters the coagulation liquid in the coagulation bath after passing through the sleeve.

5. The preparation device according to claim 1, characterized in that The width of the spinneret is 10-200 cm.

6. The preparation device according to claim 5, characterized in that: The width of the spinneret is 30-120 cm.

7. The preparation device according to claim 1, characterized in that: The device for preparing carbon fiber flat yarn precursor further includes a lead-out mechanism, which is used to lead the carbon fiber flat yarn precursor out of the coagulation liquid.

8. The preparation device according to claim 1, characterized in that The device for preparing carbon fiber flat yarn precursor further comprises one or more of a washing mechanism, a drying mechanism, an oiling mechanism, and a yarn collecting mechanism.

9. A method for preparing carbon fiber flat yarn precursor, characterized in that: The preparation method comprises: Spinning step: polyacrylonitrile spinning solution is ejected through a straight-line spinneret; Gas supply step: applying ethylene and / or propylene gas to the polyacrylonitrile spinning stock solution ejected from the spinneret, so that a film is formed on the surface of the ejected polyacrylonitrile spinning stock solution, and ethylene and / or propylene are adsorbed on the surface of the film to form an adsorption layer; Coagulation step: allowing the ejected polyacrylonitrile spinning solution to enter the coagulation solution to form the polyacrylonitrile spinning solution into polyacrylonitrile coagulated filaments; Calendering step: applying pressure to the polyacrylonitrile coagulated filaments in the coagulation liquid at a pressure of not less than 10 MPa to obtain the carbon fiber flat filaments; Wherein, the width of the carbon fiber flat yarn precursor is 10-200 cm, and the thickness of the carbon fiber flat yarn precursor is 5-15 μm.

10. The preparation method according to claim 9, characterized in that In the calendering step, the polyacrylonitrile coagulated filaments are pressed once or multiple times.

11. The preparation method according to claim 9, characterized in that In the gas supply step, the volume fraction of ethylene is 30-90%, and the volume fraction of propylene is 30-90%.

12. The preparation method according to claim 9, characterized in that The polyacrylonitrile spinning solution is obtained by dissolving polyacrylonitrile in a solvent, and the solvent is dimethylformamide or dimethyl sulfoxide.

13. The preparation method according to claim 9, characterized in that In the polyacrylonitrile spinning solution, the mass fraction of polyacrylonitrile is 10-30%.

14. The preparation method according to claim 13, characterized in that In the polyacrylonitrile spinning solution, the mass fraction of polyacrylonitrile is 17-26%.

15. The preparation method according to claim 9, characterized in that The width of the carbon fiber flat yarn precursor is 30-120 cm, and the thickness of the carbon fiber flat yarn precursor is 5-10 μm.

16. The preparation method according to claim 9, characterized in that After the calendering step, the method further includes the step of leading the carbon fiber flat yarn out of the coagulation liquid.

17. The preparation method according to claim 16, characterized in that After the carbon fiber flat yarn precursor is led out of the coagulation liquid, the method further comprises performing one or more steps of washing, drying, oiling, and collecting the carbon fiber flat yarn precursor.

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