CN115637508A - Carbonization process of carbon fiber and carbon fiber thereof - Google Patents
Carbonization process of carbon fiber and carbon fiber thereof Download PDFInfo
- Publication number
- CN115637508A CN115637508A CN202110817829.0A CN202110817829A CN115637508A CN 115637508 A CN115637508 A CN 115637508A CN 202110817829 A CN202110817829 A CN 202110817829A CN 115637508 A CN115637508 A CN 115637508A
- Authority
- CN
- China
- Prior art keywords
- temperature
- carbonization furnace
- carbon fiber
- temperature carbonization
- zone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000003763 carbonization Methods 0.000 title claims abstract description 188
- 229920000049 Carbon (fiber) Polymers 0.000 title claims abstract description 98
- 239000004917 carbon fiber Substances 0.000 title claims abstract description 98
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 85
- 238000000034 method Methods 0.000 title claims abstract description 33
- 230000008569 process Effects 0.000 title claims abstract description 32
- 239000000835 fiber Substances 0.000 claims abstract description 66
- 238000006243 chemical reaction Methods 0.000 claims abstract description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 49
- 229910052757 nitrogen Inorganic materials 0.000 claims description 22
- 238000010000 carbonizing Methods 0.000 claims description 8
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 5
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 19
- 238000005265 energy consumption Methods 0.000 abstract description 6
- 238000010923 batch production Methods 0.000 abstract description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 16
- 230000000052 comparative effect Effects 0.000 description 15
- 230000001276 controlling effect Effects 0.000 description 15
- 229910052799 carbon Inorganic materials 0.000 description 11
- 229920000642 polymer Polymers 0.000 description 8
- 239000002243 precursor Substances 0.000 description 8
- 230000007547 defect Effects 0.000 description 7
- 238000001035 drying Methods 0.000 description 7
- 229920002239 polyacrylonitrile Polymers 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- 230000003647 oxidation Effects 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 description 4
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 238000001914 filtration Methods 0.000 description 4
- 238000009987 spinning Methods 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 238000006068 polycondensation reaction Methods 0.000 description 3
- 238000004513 sizing Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 238000004381 surface treatment Methods 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- JAHNSTQSQJOJLO-UHFFFAOYSA-N 2-(3-fluorophenyl)-1h-imidazole Chemical compound FC1=CC=CC(C=2NC=CN=2)=C1 JAHNSTQSQJOJLO-UHFFFAOYSA-N 0.000 description 2
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 2
- 239000007900 aqueous suspension Substances 0.000 description 2
- 230000009920 chelation Effects 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000008676 import Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229920002521 macromolecule Polymers 0.000 description 2
- LVHBHZANLOWSRM-UHFFFAOYSA-N methylenebutanedioic acid Natural products OC(=O)CC(=C)C(O)=O LVHBHZANLOWSRM-UHFFFAOYSA-N 0.000 description 2
- 239000013081 microcrystal Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 238000007493 shaping process Methods 0.000 description 2
- 238000010557 suspension polymerization reaction Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000004580 weight loss Effects 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000007380 fibre production Methods 0.000 description 1
- 238000005087 graphitization Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000011550 stock solution Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- -1 surface treatment Chemical compound 0.000 description 1
- 238000004227 thermal cracking Methods 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
Landscapes
- Inorganic Fibers (AREA)
Abstract
The invention discloses a carbonization process of carbon fiber and the carbon fiber, wherein pre-oxidized fiber is subjected to carbonization reaction in a low-temperature carbonization furnace and a high-temperature carbonization furnace in sequence, and the running speed in the high-temperature carbonization furnace is controlled to be 11-15m/min. The invention can greatly shorten the high-temperature carbonization time by controlling the running speed of the pre-oxidized fiber in the high-temperature carbonization furnace within the range, thereby improving the production efficiency and reducing the energy consumption and the production cost; the carbon fiber prepared by the carbonization process has good mechanical property and larger bulk density, and is suitable for industrial batch production.
Description
Technical Field
The invention belongs to the technical field of carbon fibers, and particularly relates to a carbonization process of carbon fibers and carbon fibers thereof.
Background
The carbon fiber has a series of excellent performances such as high specific strength, high specific modulus, high temperature resistance, corrosion resistance, fatigue resistance, radiation resistance, electric conduction, heat transfer, shock absorption, noise reduction, small relative density and the like, is widely applied to advanced fields such as aerospace, national defense and military and the like, and civil industries such as high-grade sports goods, medical instruments and the like as a high-technology material, and plays an increasingly important role.
At present, 98 percent of the using amount of domestic common carbon fiber depends on import, the domestic carbon fiber supply is very tense, and the high-performance carbon fiber is basically difficult to import from a regular channel, so the domestic high-performance carbon fiber supply is very severe. In addition, due to the restriction of foreign technology blockade and the restriction of higher production cost, most domestic carbon fiber enterprises are in a loss state in recent years, and how to improve the production efficiency is solved, so that the unit consumption of electric energy is reduced, and the cost is saved, thereby becoming the challenge problem of each large carbon fiber enterprise. Although several domestic carbon fiber enterprises claim to produce thousands of tons, the actual productivity does not exceed hundreds of tons, and the carbon fiber enterprises only have production capacity and do not have actual output capacity, the high-temperature carbonization time of the carbon fibers of the existing carbon fiber enterprises is about 1 minute, and the problems of large energy consumption, high cost, unstable product quality and the like exist due to overlong high-temperature carbonization time. Therefore, shortening the high temperature carbonization time is an effective way to increase the production capacity and reduce the cost.
In view of the above, the present invention is particularly proposed.
Disclosure of Invention
The invention aims to solve the technical problems of long carbonization time, low production efficiency and high production cost of the existing carbon fiber, and provides a carbonization process of the carbon fiber and the carbon fiber thereof, so that the carbonization time of the carbon fiber is short, the production efficiency is high, the production cost is low, and the mechanical property of the obtained carbon fiber is good.
In order to solve the technical problems, the invention adopts the technical scheme that:
a process for carbonizing a carbon fiber, comprising:
and the pre-oxidized fiber sequentially passes through a low-temperature carbonization furnace and a high-temperature carbonization furnace for carbonization reaction, and the running speed in the high-temperature carbonization furnace is 11-15m/min.
When existing carbon fiber production enterprises produce carbon fibers, the running speed of pre-oxidized fibers in a high-temperature carbonization furnace is about 10m/min, the high-temperature carbonization time is about 1 minute at the running speed, and the problems of high energy consumption and high cost are caused by overlong high-temperature carbonization time. According to the invention, the running speed of the pre-oxidized fiber in the high-temperature carbonization furnace is controlled within the range by increasing the running speed of the pre-oxidized fiber in the high-temperature carbonization furnace, so that the high-temperature carbonization time of the pre-oxidized fiber in the high-temperature carbonization furnace is controlled within 35-45s, the high-temperature carbonization time is greatly shortened, the production efficiency is improved, and the energy consumption and the production cost are reduced.
It is understood that the high temperature carbonization time is a residence time of the pre-oxidized fiber in the high temperature carbonization furnace, i.e., a total time of the high temperature carbonization.
The production process of the carbon fiber generally obtains pre-oxidized fiber by pre-oxidizing carbon fiber precursor; and sequentially carrying out low-temperature carbonization and high-temperature carbonization treatment on the pre-oxidized fiber to obtain the carbon fiber. In the carbonization process of the pre-oxidized fiber, the hybrid carbon-carbon atom bond distance is gradually increased, the enrichment of carbon elements and the removal of non-carbon elements are from outside to inside processes, the crystal size is increased, the graphitization degree is improved, the disordered-layer graphite structure tends to be perfect, and finally the carbon fiber with the disordered-layer graphite structure is converted.
Of course, post-treatment of the carbon fiber including surface treatment, sizing treatment and drying treatment may be performed to obtain the treated carbon fiber.
Further, the running speed in the high-temperature carbonization furnace is 12.5-14.5m/min.
Further, a high-temperature carbonization furnace with multiple temperature zones is adopted for high-temperature carbonization reaction, and the temperature of the high-temperature carbonization furnace is 800-1500 ℃.
Further, the temperature rise gradient of an adjacent temperature zone in the high-temperature carbonization furnace is 120-200 ℃;
preferably, the temperature rise gradient of the adjacent temperature zone in the high-temperature carbonization furnace is 170-200 ℃.
Further, a high-temperature carbonization furnace with five temperature zones is adopted to carry out high-temperature carbonization reaction on the pre-oxidized fiber;
the temperature of the first temperature zone of the high-temperature carbonization furnace is 800-830 ℃, the temperature of the second temperature zone is 940-990 ℃, the temperature of the third temperature zone is 1080-1170 ℃, the temperature of the fourth temperature zone is 1230-1370 ℃, and the temperature of the fifth temperature zone is 1380-1490 ℃.
Further, the temperature of a first temperature zone of the high-temperature carbonization furnace is 800-820 ℃, the temperature of a second temperature zone is 960-980 ℃, the temperature of a third temperature zone is 1120-1170 ℃, the temperature of a fourth temperature zone is 1280-1370 ℃, and the temperature of a fifth temperature zone is 1440-1490 ℃;
preferably, the temperature of the first temperature zone of the high-temperature carbonization furnace is 800 ℃, the temperature of the second temperature zone is 980 ℃, the temperature of the third temperature zone is 1170 ℃, the temperature of the fourth temperature zone is 1370 ℃, and the temperature of the fifth temperature zone is 1490 ℃.
If the running speed of the pre-oxidized fiber in the high-temperature carbonization furnace is directly increased, although the carbonization time is shortened, the temperature of each temperature zone in the original high-temperature carbonization furnace cannot meet the high-temperature carbonization of the pre-oxidized fiber, so that the impurity elements in the carbon fiber are not completely carbonized, and the content of the carbon elements in the carbon fiber is reduced more. The invention controls the crosslinking and polycondensation reaction by adjusting the temperature of each temperature zone in the high-temperature carbonization furnace and setting corresponding temperature rise gradient, so that the internal structure of the fiber is more stable, the fiber can reach the required carbonization degree more quickly, and the carbonization time is shortened.
It can be understood that the temperature of each temperature zone in the high-temperature carbonization furnace can be independently controlled to meet different requirements of different carbon fibers on process conditions.
Further, in the high-temperature carbonization reaction, the carbon fiber is drawn by a drawing roller, and the roller speed precision of the drawing roller is controlled to be 0.0001-0.0015m/min;
preferably, the roller speed accuracy of the drawing roller is controlled to be 0.0010m/min.
Preferably, the drafting roller comprises a frequency converter, and the roller speed accuracy of the drafting roller is controlled by adjusting the current input value and the range output value parameters of the frequency converter.
In above-mentioned scheme, accurate control through fibre draft makes tension stability improve, and the inside graphite micrite of fibre is to fine and close orderly arrangement for fibrous bulk density increases, and the porosity reduces, and the intensity index of final carbon fiber steadily improves, effectively avoids the production of fibre broken filament and disconnected silk, realizes the industrial stabilization production.
Further, the draft ratio at the inlet of the high temperature carbonization furnace is 1.0140-1.0530, and the draft ratio at the outlet of the high temperature carbonization furnace is 0.9500-0.9750.
When the temperature in the high-temperature carbonization furnace rises according to the temperature gradient, the decomposition speed in the fiber is accelerated, small molecular gas generated by decomposition overflows rapidly, the defects of the fiber structure are increased, along with a large amount of thermal cracking in the fiber, the original orientation is disoriented, and the mechanical property of the fiber is reduced.
Further, the pre-oxidized fiber is subjected to high-temperature carbonization reaction in a high-temperature carbonization furnace in the nitrogen atmosphere, wherein the flow rate of nitrogen is 150-190Nm 3 H; preferably, the flow rate of the nitrogen gas is 150-175Nm 3 H; more preferably, the flow rate of the nitrogen gas is 150 to 155Nm 3 /h。
The polycondensation reaction mainly occurs in the high-temperature carbonization furnace, and along with the great increase of the running speed of the pre-oxidized fiber in the high-temperature carbonization furnace and the great reduction of the high-temperature carbonization time, a great amount of waste gas such as HCN and N is instantly increased in the high-temperature carbonization furnace 2 The nitrogen amount that lets in the high temperature carbonization stove is reduced through the adjustment, can guarantee that atmosphere in the high temperature carbonization stove is balanced, utilizes nitrogen gas in time to take away the micromolecule result that the carbonization process decomposed, avoids blockking up fibre surface gas pocket because of the waste discharge is unobstructed, makes non-carbon element remain and causes the defect inside the fibre, influences carbon fiber strength. In addition, the nitrogen can well isolate oxygen in the high-temperature carbonization furnace, and avoid carbon on the cyclic macromolecules from being attacked by the oxygenAtom to form CO and CO 2 So as to increase the thermal weight loss of the fiber, cause defects and reduce the strength of the fiber.
The carbon fiber produced by any one of the carbonization processes has the tensile strength of 4500-4700Mpa and the bulk density of 1.765-1.777g/cm 3 。
Specifically, the preparation method of the carbon fiber comprises the following steps:
(1) Mixing acrylonitrile, methyl acrylate and itaconic acid according to a certain mass ratio to obtain a mixture, continuously carrying out aqueous suspension polymerization to obtain a polymer, terminating the chelation reaction of the polymer, removing unreacted monomers by using a stripping tower, filtering by using a water washing filter, granulating, forming, and drying to obtain a powdery polymer;
(2) Dissolving a powdery polymer in dimethylacetamide, heating, cooling, filtering to obtain a spinning stock solution, spinning, feeding formed monofilaments into dimethylacetamide solidified bath liquid, carrying out double diffusion forming to obtain nascent fibers, and then carrying out washing, drafting, oiling, drying, steam drafting and steam shaping to finally form carbon fiber precursors;
(3) The carbon fiber precursor is subjected to preoxidation by a preoxidation furnace to obtain preoxidation fiber, the preoxidation fiber is subjected to carbonization reaction by a low-temperature carbonization furnace and a high-temperature carbonization furnace in sequence to obtain carbon fiber, and then the carbon fiber product is obtained by surface treatment, sizing, drying and rolling;
the pre-oxidation process and the low-temperature carbonization process of the carbon fiber precursor can adopt a pre-oxidation furnace and a low-temperature carbonization furnace of a multi-temperature area in the traditional technology to react, wherein the temperature range of the pre-oxidation furnace is 240-280 ℃, and the temperature range of the low-temperature carbonization furnace is 300-800 ℃.
The Polyacrylonitrile (PAN) -based carbon fiber precursor is prepared by the conventional preparation method, the scheme only provides one preparation method in the prior art, and the Polyacrylonitrile (PAN) -based carbon fiber precursor prepared by other preparation methods is also suitable for the preparation method.
After adopting the technical scheme, compared with the prior art, the invention has the following beneficial effects:
according to the invention, the high-temperature carbonization time of the pre-oxidized fiber in the high-temperature carbonization furnace is controlled to be 35-45s by increasing the running speed of the pre-oxidized fiber in the high-temperature carbonization furnace, so that the high-temperature carbonization time is greatly shortened, the production efficiency is improved, and the energy consumption and the production cost are reduced.
According to the invention, the nitrogen amount introduced into the high-temperature carbonization furnace is adjusted and reduced, so that the atmosphere balance in the high-temperature carbonization furnace can be ensured, small molecular products decomposed in the carbonization process are taken away in time by using the nitrogen, and the defects that non-carbon elements remain in the fiber to cause the blockage of pores on the surface of the fiber due to the obstructed waste discharge and influence on the strength of the carbon fiber are avoided. In addition, the nitrogen can well isolate oxygen in the high-temperature carbonization furnace, and CO generated by oxygen attacking carbon atoms on the cyclic macromolecules are avoided 2 So as to increase the thermal weight loss of the fiber, cause defects and reduce the strength of the fiber.
The invention controls the crosslinking and polycondensation reaction by adjusting the temperature of each temperature zone in the high-temperature carbonization furnace and setting corresponding temperature rise gradient, so that the internal structure of the fiber is more stable, the high-temperature carbonization speed of the fiber can be accelerated, and the high-temperature carbonization time is shortened.
According to the invention, the tension stability is improved through the accurate control of fiber drafting, the graphite microcrystals in the fibers are arranged in a compact and ordered manner, the volume density of the fibers is increased, the porosity is reduced, and finally the strength index of the carbon fibers is stably improved.
According to the invention, the draft ratio of the inlet and the outlet of the high-temperature carbonization furnace is reasonably adjusted, so that the tension stability of the fiber in the operation process is improved, the preferred orientation of the carbon net plane to the fiber axis is maintained, the molecular arrangement is more compact, and the strength of the carbon fiber is obviously improved. The carbon fiber prepared by the carbonization process has good mechanical property and larger bulk density, and is suitable for industrial batch production.
The following describes embodiments of the present invention in further detail.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments are clearly and completely described below, and the following embodiments are used for illustrating the present invention and are not used for limiting the scope of the present invention.
Example 1
In this embodiment, the carbon fiber preparation method specifically includes the following steps:
(1) Mixing acrylonitrile, methyl acrylate and itaconic acid according to a certain mass ratio to obtain a mixture, continuously carrying out aqueous suspension polymerization to obtain a polymer, terminating the chelation reaction of the polymer, removing unreacted monomers by using a stripping tower, filtering by using a water washing filter, granulating, forming, and drying to obtain a powdery polymer;
(2) Dissolving a powdery polymer in dimethylacetamide, heating, cooling, filtering to obtain a spinning solution, spinning, allowing the formed monofilaments to enter dimethylacetamide solidified bath liquid, performing double diffusion molding to obtain nascent fibers, and performing washing, drafting, oiling, drying, steam drafting and steam shaping to finally form Polyacrylonitrile (PAN) -based carbon fiber precursors;
(3) The method comprises the following steps of pre-oxidizing carbon fiber precursors in an oxidation furnace to obtain pre-oxidized fibers, sequentially performing low-temperature carbonization reaction on the pre-oxidized fibers in a low-temperature carbonization furnace, performing high-temperature carbonization reaction in a high-temperature carbonization furnace under the atmosphere of nitrogen to obtain carbon fibers, and performing surface treatment, sizing, drying and rolling to obtain a carbon fiber product. Wherein the temperature of the pre-oxidation furnace is 240-280 ℃, and the temperature of the low-temperature carbonization furnace is 300-800 ℃.
The running speed of the pre-oxidized fiber in the high-temperature carbonization furnace is controlled to be 14.5m/min, the carbonization time in the high-temperature carbonization furnace is controlled to be 36s, the temperature of five temperature regions of the high-temperature carbonization furnace is respectively 800 ℃, 930 ℃, 1060 ℃, 1190 ℃ and 1320 ℃, and the flow rate of nitrogen is 183Nm 3 H; and the carbon fiber is drafted through the drafting roller, the roller speed precision of the drafting roller is controlled to be 0.0001m/min, the drafting ratio at the inlet of the high-temperature carbonization furnace is 1.0140-1.0340, and the drafting ratio at the outlet of the high-temperature carbonization furnace is 0.9515-0.9753.
Example 2
The present example differs from example 1 in that: the temperature of the five temperature zones of the high-temperature carbonization furnace is respectively 800 ℃, 940 ℃, 1080 ℃, 1220 ℃ and 1360 ℃, and the flow rate of nitrogen is 170Nm 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.0001m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.0160-1.0365, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.9530-0.9730.
Example 3
This example differs from example 1 in that: the temperature of the five temperature zones of the high-temperature carbonization furnace is respectively 800 ℃, 950 ℃, 1100 ℃, 1250 ℃ and 1400 ℃, and the flow rate of nitrogen is 162Nm 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.0010m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.0240-1.0390, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.9550-0.9710.
Example 4
The present example differs from example 1 in that: the temperature of the five temperature zones of the high-temperature carbonization furnace is respectively 800 ℃, 960 ℃, 1120 ℃, 1280 ℃ and 1440 ℃, and the flow rate of nitrogen is 155Nm 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.0010m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.0260-1.0430, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.9600-0.9700.
Example 5
This example differs from example 1 in that: the temperature of the five temperature zones of the high-temperature carbonization furnace is respectively 800 ℃, 970 ℃, 1140 ℃, 1310 ℃ and 1480 ℃, and the flow rate of nitrogen is 152Nm 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.0010m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.0330-1.0520, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.9620-0.9710.
Example 6
This example differs from example 1 in that: the temperature of the five temperature regions of the high-temperature carbonization furnace is 800 ℃, 980 ℃, 1170 ℃, 1370 ℃ and 1490 ℃, and the flow rate of nitrogen is 155Nm 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.0010m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.0330-1.0530, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.9620-0.9710.
Example 7:
this example differs from example 1 in that: controlling the running speed of the pre-oxidized fiber in a high-temperature carbonization furnace to be 13.8m/min, the carbonization time in the high-temperature carbonization furnace to be 38s, the temperatures of five temperature zones of the high-temperature carbonization furnace to be 800 ℃, 990 ℃, 1100 ℃, 1250 ℃ and 1390 ℃ respectively, and the flow rate of nitrogen to be 160Nm 3 H; the carbon fiber is drawn by a drawing roller, and the roller speed precision of the drawing roller is controlled to be 0.001m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.015-1.035, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.950-0.975.
Example 8:
this example differs from example 1 in that: controlling the running speed of the pre-oxidized fiber in a high-temperature carbonization furnace to be 13m/min, the carbonization time in the high-temperature carbonization furnace to be 40s, the temperatures of five temperature zones of the high-temperature carbonization furnace to be 800 ℃, 980 ℃, 1095 ℃, 1240 ℃ and 1380 ℃, and the flow rate of nitrogen to be 172Nm & lt/EN & gt 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.001m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.015-1.035, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.950-0.975.
Example 9:
the present example differs from example 1 in that: controlling the running speed of the pre-oxidized fiber in a high-temperature carbonization furnace to be 12.4m/min, the carbonization time in the high-temperature carbonization furnace to be 42s, the temperatures of five temperature zones of the high-temperature carbonization furnace to be 800 ℃, 960 ℃, 1090 ℃, 1220 ℃ and 1360 ℃, and the flow rate of nitrogen to be 185Nm & m 3 H; the carbon fiber is drawn by a drawing roller, and the roller speed precision of the drawing roller is controlled to be 0.001m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.015-1.035, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.950-0.975.
Example 10:
this implementationThe example differs from example 1 in that: controlling the running speed of the pre-oxidized fiber in a high-temperature carbonization furnace to be 11.6m/min, the carbonization time in the high-temperature carbonization furnace to be 45s, the temperatures of five temperature zones of the high-temperature carbonization furnace to be 800 ℃, 940 ℃, 1070 ℃, 1230 ℃ and 1350 ℃, and the flow rate of nitrogen to be 190Nm & lt/EN & gt 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.001m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.015-1.035, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.950-0.975.
Comparative example 1:
the comparative example differs from example 1 in that: controlling the running speed of the pre-oxidized fiber in a high-temperature carbonization furnace to be 10m/min, the carbonization time in the high-temperature carbonization furnace to be 53s, the temperatures of five temperature zones of the high-temperature carbonization furnace to be 800 ℃, 930 ℃, 1070 ℃, 1220 ℃ and 1380 ℃ respectively, and the flow rate of nitrogen to be 190Nm 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.01m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.01-1.03, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.95-0.97.
Comparative example 2:
the present comparative example differs from comparative example 1 in that: the running speed of the pre-oxidized fiber in the high-temperature carbonization furnace is controlled to be 14.5m/min, the carbonization time in the high-temperature carbonization furnace is controlled to be 36s, and other process conditions are not changed.
Comparative example 3:
the comparative example differs from example 6 in that: the temperature of the five temperature zones of the high-temperature carbonization furnace is respectively 800 ℃, 980 ℃, 1170 ℃, 1370 ℃ and 1580 ℃, and the flow of nitrogen is 190Nm 3 H; drafting the carbon fiber by a drafting roller, and controlling the roller speed precision of the drafting roller to be 0.001m/min; the draft ratio at the inlet of the high-temperature carbonization furnace is 1.033-1.053, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.962-0.971.
It should be noted that: the setting ranges of the inlet draft ratio of the high-temperature carbonization furnace and the outlet draft ratio of the high-temperature carbonization furnace in examples 1 to 10 and comparative examples 1 to 3 were obtained by adjusting the tension change of the carbon fiber measured in real time a plurality of times.
The carbon fibers obtained in examples 1 to 10 and comparative examples 1 to 3 were subjected to bulk density, tensile strength and carbon content tests, wherein the test range of bulk density was obtained by performing multiple sampling tests on the carbon fibers, and the test range of tensile strength was obtained by selecting 200 carbon fiber filaments and performing multiple measurements.
The test results are shown in table 1:
it can be seen from the data of examples 1 to 10 and comparative examples 1 to 2 that, in comparative example 2, the running speed of the pre-oxidized fiber in the high-temperature carbonization furnace is directly increased on the basis of comparative example 1, and although the carbonization time is shortened, the temperature of each temperature zone in the high-temperature carbonization furnace cannot meet the high-temperature carbonization of the pre-oxidized fiber, so that the impurity elements in the carbon fiber are not completely carbonized, and the content of the carbon elements in the carbon fiber is greatly reduced. In the embodiment of the invention, the operation speed of the pre-oxidized fiber in the high-temperature carbonization furnace is increased, and other parameters of the carbonization process are adjusted to be within a reasonable range, so that the high-temperature carbonization time is shortened, the production efficiency of the carbon fiber is greatly improved, the energy consumption and the production cost are reduced, and the content of carbon elements in the prepared carbon fiber is not reduced greatly.
According to the data of the examples 1 to 10 and the comparative examples 1 to 3, the nitrogen amount introduced into the high-temperature carbonization furnace is adjusted and reduced, so that the atmosphere balance in the high-temperature carbonization furnace can be ensured, the small molecular products decomposed in the carbonization process can be taken away in time by using the nitrogen, and the defects that the non-carbon elements are remained in the fiber to cause the defect and influence on the strength of the carbon fiber due to the blockage of the air holes on the surface of the fiber caused by the unsmooth waste discharge can be avoided. And the tension stability is improved through the accurate control of fiber drafting, and the graphite microcrystals in the fibers are arranged in a compact and ordered manner, so that the volume density of the fibers is increased, the porosity is reduced, and finally the strength index of the carbon fibers is stably improved.
As can be seen from the data of examples 1 to 10, comparative example 1 and comparative example 3, the temperature of each temperature zone in the high-temperature carbonization furnace in example 6 of the present invention is adjusted to be within a reasonable range, and the prepared carbon fiber has a tensile strength as high as 4700MPa and excellent mechanical properties. The tensile strength of the prepared carbon fiber is reduced on the contrary along with the continuous increase of the highest temperature in the high-temperature carbonization furnace, and the prepared carbon fiber has good mechanical property and larger bulk density by reasonably regulating and controlling various process parameters in the high-temperature carbonization process of the carbon fiber, and is suitable for industrial batch production.
Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. A process for carbonizing carbon fiber, comprising:
and the pre-oxidized fiber sequentially passes through a low-temperature carbonization furnace and a high-temperature carbonization furnace for carbonization reaction, and the running speed in the high-temperature carbonization furnace is 11-15m/min.
2. A process for carbonizing a carbon fiber according to claim 1, characterized in that:
the running speed in the high-temperature carbonization furnace is 12.5-14.5m/min.
3. The process for the carbonization of carbon fibers according to claim 1 or 2, wherein:
and (2) carrying out high-temperature carbonization reaction by adopting a high-temperature carbonization furnace with multiple temperature areas, wherein the temperature of the high-temperature carbonization furnace is 800-1500 ℃.
4. A process for carbonizing a carbon fiber according to claim 3, characterized in that:
the temperature rise gradient of adjacent temperature areas in the high-temperature carbonization furnace is 120-200 ℃;
preferably, the temperature rise gradient of the adjacent temperature zone in the high-temperature carbonization furnace is 170-200 ℃.
5. A process for carbonizing a carbon fiber according to claim 3, characterized in that:
carrying out high-temperature carbonization reaction on the pre-oxidized fiber by adopting a high-temperature carbonization furnace with five temperature zones;
the temperature of the first temperature zone of the high-temperature carbonization furnace is 800-830 ℃, the temperature of the second temperature zone is 940-990 ℃, the temperature of the third temperature zone is 1080-1170 ℃, the temperature of the fourth temperature zone is 1230-1370 ℃, and the temperature of the fifth temperature zone is 1380-1490 ℃.
6. A process for carbonizing a carbon fiber according to claim 5, characterized in that:
the temperature of a first temperature zone of the high-temperature carbonization furnace is 800-820 ℃, the temperature of a second temperature zone is 960-980 ℃, the temperature of a third temperature zone is 1120-1170 ℃, the temperature of a fourth temperature zone is 1280-1370 ℃, and the temperature of a fifth temperature zone is 1440-1490 ℃;
preferably, the temperature of the first temperature zone of the high-temperature carbonization furnace is 800 ℃, the temperature of the second temperature zone is 980 ℃, the temperature of the third temperature zone is 1170 ℃, the temperature of the fourth temperature zone is 1370 ℃, and the temperature of the fifth temperature zone is 1490 ℃.
7. A process for carbonizing a carbon fiber according to any one of claims 1 to 6, characterized in that:
in the high-temperature carbonization reaction, the carbon fiber is drawn by a drawing roller, and the roller speed precision of the drawing roller is controlled to be 0.0001-0.0015m/min;
preferably, the roller speed accuracy of the drawing roller is controlled to be 0.0010m/min.
8. The process for carbonizing a carbon fiber according to claim 7, wherein:
the draft ratio at the inlet of the high-temperature carbonization furnace is 1.0140-1.0530, and the draft ratio at the outlet of the high-temperature carbonization furnace is 0.9500-0.9750.
9. The process for the carbonization of carbon fibers according to claim 1 or 2, wherein:
the pre-oxidized fiber is subjected to high-temperature carbonization reaction in a high-temperature carbonization furnace under the nitrogen atmosphere, wherein the flow rate of nitrogen is 150-190Nm 3 H; preferably, the flow rate of the nitrogen gas is 150-175Nm 3 H; more preferably, the flow rate of the nitrogen gas is 150-155Nm 3 /h。
10. A carbon fiber produced by the carbonization process according to any one of claims 1 to 9, wherein:
the tensile strength of the carbon fiber is 4500-4700Mpa, and the bulk density of the carbon fiber is 1.765-1.777g/cm 3 。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110817829.0A CN115637508A (en) | 2021-07-20 | 2021-07-20 | Carbonization process of carbon fiber and carbon fiber thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110817829.0A CN115637508A (en) | 2021-07-20 | 2021-07-20 | Carbonization process of carbon fiber and carbon fiber thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115637508A true CN115637508A (en) | 2023-01-24 |
Family
ID=84940025
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110817829.0A Pending CN115637508A (en) | 2021-07-20 | 2021-07-20 | Carbonization process of carbon fiber and carbon fiber thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115637508A (en) |
-
2021
- 2021-07-20 CN CN202110817829.0A patent/CN115637508A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109881280B (en) | Polyacrylonitrile fiber, preparation method and preparation method of carbon fiber | |
| CN107287699B (en) | Rapid preoxidation process for polyacrylonitrile-based carbon fiber precursor | |
| CN110055624B (en) | Pre-oxidation method of polyacrylonitrile fiber, polyacrylonitrile carbon fiber and preparation method | |
| CN111139554B (en) | High-permeability polyacrylonitrile-based carbon fiber and preparation method thereof | |
| CN108486689B (en) | Preparation method of high-modulus high-thermal-conductivity asphalt-based carbon fiber continuous filament | |
| CN111118671B (en) | Preparation method of 25k large-tow carbon fiber | |
| CN109137117B (en) | Method for dry-jet wet-spinning low-swelling degree polyacrylonitrile nascent fiber | |
| KR101395811B1 (en) | Preparation method for carbon fiber with high performance using textile grade polyacrylonitrile fiber | |
| CN109402795B (en) | Pre-oxidation method and equipment for improving mechanical property of carbon fiber | |
| CN112226851B (en) | Preparation method of polyacrylonitrile-based carbon fiber | |
| CN111945251A (en) | Ultrahigh-strength medium-modulus polyacrylonitrile-based carbon fiber and preparation method thereof | |
| CN112760752B (en) | PAN-based carbon fiber and preparation method thereof | |
| JP4662450B2 (en) | Carbon fiber manufacturing method | |
| CN115637508A (en) | Carbonization process of carbon fiber and carbon fiber thereof | |
| CN115369521B (en) | Pre-oxidation process of carbon fiber precursor and polyacrylonitrile carbon fiber pre-oxidized precursor | |
| WO2024001261A1 (en) | Preparation method for high-performance, low-cost carbon fiber | |
| CN103668561B (en) | A kind of method by controlling pre-oxidized fibers structure to prepare high-performance carbon fibre | |
| CN210657241U (en) | Thermal stabilization device for carbon fiber production | |
| CN115928268A (en) | Polyacrylonitrile initial-stage thermal oxidation stabilized fiber and preparation method and application thereof | |
| CN111088540B (en) | Preparation method of high-performance polyacrylonitrile fiber | |
| CN111926414A (en) | Low-cost high-strength carbon fiber | |
| CN114687010B (en) | High-strength high-modulus high-elongation carbon fiber and preparation method thereof | |
| JP2004197278A (en) | Method for producing carbon fiber | |
| JPH02264011A (en) | Acrylic fiber for graphite fibers | |
| CN114474787B (en) | Method for preparing umbrella rib from carbon fiber-based resin composite material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |