CN1442519A - New technology and device for pdyacrylonitril fiber preoxidation and carbonation - Google Patents
New technology and device for pdyacrylonitril fiber preoxidation and carbonation Download PDFInfo
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- CN1442519A CN1442519A CN 02103974 CN02103974A CN1442519A CN 1442519 A CN1442519 A CN 1442519A CN 02103974 CN02103974 CN 02103974 CN 02103974 A CN02103974 A CN 02103974A CN 1442519 A CN1442519 A CN 1442519A
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Abstract
A process for preoxidizing and carbonizing polyacrylonitrile fibres to obtain carbon fibres features the use of a HF negative-pressure plasma heater which is composed of HF power supply, parallel plate electrodes, flat reaction cavity made of quartz glass, and the accessory for generating negative pressure in reacion cavity and proportioning N2 and O2. The plasma generated in the reaction cavity can greatly lower the temp. of preoxidizing and carbonizing, so both steps can be performed in a single heater, resulting in low energy consumption and low cost.
Description
Technical field
The invention belongs to producing the improvement of pdyacrylonitril carbon fibre technology and device.
Background technology
Carbon fibre has a series of advantages such as low-density, high strength, high temperature resistant, anticorrosive, low resistance, high thermal conductance, low-expansion coefficient, anti-chemical radiation, also have fiber flexibility, can work out characteristic and relatively inexpensive characteristics, thereby as the enhancing body of high-performance composite materials and be applied to becoming the important composite in fields such as Aeronautics and Astronautics, military affairs, physical culture, building, chemical industry widely with resin, pottery, cement, metal composite.The existing carbon fibre that uses in a large number all is to adopt pdyacrylonitril fiber to be raw material, pdyacrylonitril fiber is entered heating furnace through live-roller under drafting force, under the temperature below 400 ℃ with easy fusion composition oxidative pyrolysis, make chemical reactions such as its linear polymeric generation is crosslinked, cyclisation, oxidation, deoxidation, form the ladderlike polymer structure of better heat stability, its oxygen content is 8-10%, is referred to as pre-oxidized fibers.Above technical process is called pre-oxidation.Pre-oxidized fibers is sent into heating furnace through drawing roller again under drafting tension; (oxygen content is less than 10 milliliters/cubic metre under the high pure nitrogen protection; less than 10ppm); the control temperature is 1000 ℃-1500 ℃; heat and made pre-oxidized fibers finish carbonisation in 5-20 minute; fiber further produces chemical reactions such as crosslinked, cyclisation, polycondensation, aromatization in this process, emits H
2, NH
3, HCN, CO, CO
2, CH
4With make after a small amount of tar material that carbon content reaches more than 90% in the fiber, form the coarse parallel disorderly layer graphite-like structure of two-dimentional carbocyclic ring plane network structure and synusia, then be referred to as the pdyacrylonitril carbon fibre, this operation process is called carbonation process.In above two operations, though adding the process of thermal response is similar basically, but it is bigger that reaction condition differs, there is a large amount of organic matters can the generation fusion make it have to whole technology is divided into two independently technical process more than 400 ℃ in the contained structure that has of former silk fiber, and increased equipment investment and technology cost.In traditional processing technology, heating is carried out in electric furnace, and its structure and heating process have determined the adjusting fast reaction at random of its furnace temperature, the thermal efficiency is low, the equipment manufacturing cost height, and process treatment time is long, thereby cause the carbon fibre price higher, and have influence on its application.
Summary of the invention
The objective of the invention is to adopt new-type harp overcoming the defective that the electric furnace thermal efficiency is low, governing speed is slow, that realizes the furnace chamber thermograde adjusts and realizes once finishing of pre-oxidation carbonation process at random.
Key of the present invention is in the processing technology with the electrothermal furnace Structure Conversion that adopts in the former technology to be that to take with the high-frequency alternating current be the negative pressure plasma heater of the energy, and be the custom-designed high frequency negative pressure of technical process plasma heater, compare with the heating furnace in the former technology, working condition during its heating becomes negative pressure from normal pressure, the experiment proved that subnormal ambient is a 0.75-0.25 atmospheric pressure.In addition, owing to gas ionization under the high-frequency electric field causes oxygen molecule is arranged not only in the reaction atmosphere, and oxygen molecule and oxonium ion are arranged, thereby make oxidation reaction carry out more rapidly and thoroughly, and can reduce its reaction temperature greatly.In the preoxidation process of traditional handicraft, adopt air atmosphere below 400 ℃, in fact the nitrogen oxygen ratio in its reaction atmosphere is 78: 21, and thorough for being swift in response of oxidation, all need in the technology controlling and process in this stage suitably to improve nitrogen content: 2-7: between 3 probably 8.The employing high frequency negative pressure plasma heater of being controlled under same atmosphere can make the heating-up temperature in the pre-oxidation operation reduce between 200 ℃-380 ℃, and the temperature in the carbonation process then can be controlled between 380 ℃-680 ℃ and finish.Such result shows that the technological temperature of pre-oxidation operation and carbonation process might be connected, as long as our designed isolated plant can the realization response chamber in the distribution of large span thermograde, or the carbonation process reaction condition of saying us can realized below 400 ℃ under the new atmosphere and under the subnormal ambient, or say that we make this technological reaction temperature be controlled at rational Gradient distribution scope by specially designed heating reaction furnace, then 400 ℃ of fusions no longer are the obstacles that operation distributes just, and might realize finishing single stepping from preoxidation process and carbonization engineering.Experiment showed, the special-purpose heater of high frequency negative pressure plasma that the present invention takes, can pre-oxidation and carbonation process once be finished in same heater.
Promptly provide the structural representation of the custom-designed high frequency negative pressure of new technology of the present invention plasma heater below, and further specify in conjunction with the accompanying drawings and the objective of the invention is how to realize.
Description of drawings
Accompanying drawing 1 is the structural representation of the high frequency negative pressure plasma heater of special use in this technology.
Accompanying drawing 2 is the reactor design diagram in the step carbonization heater device.
Wherein, 1 represents high frequency voltage source, and 1A represents the high frequency electric distributor, 1B represents the high frequency voltage adjuster, 2 represent the plasma exciting electrode, and 3 are quartz glass system reaction chamber, and 3A is for advancing the silk mouth, 3B is a filament mouth, 4 is preceding sealing device, and 4A is an inflation inlet, and 5 is the back seal closure, 5A is a bleeding point, 6 for putting the silk wheel, and 7 is wire drawing wheel, and 8 representatives are by the reaction atmosphere blending device of computer control, 8A representation quality flowmeter, 8B represents mixing chamber, 2A, 2B, but 2C represents the parallel-plate electrode of independent roll adjustment, 3A, on behalf of high pure nitrogen, 3B replenish the input port, 9 is vavuum pump, and 10 represent fibre bundle.
The specific embodiment
For realizing purpose of the present invention, realization to the improvement of existing carbon fiber processing technology and specialized designs be the negative pressure plasma heater of the energy with high frequency electric source 1, the flat cavity body that this device ionic medium reaction chamber 3 is made for quartz glass, both ends of the surface are provided with into filament mouth (3A, 3B), and seal closure (4,5) before and after disposing.Its effect is all to be under the sealing state putting silk wheel 6 and wire drawing wheel 7 before the main structural components in the differential wire drawing mechanism, to form the subnormal ambient of reaction chamber.It is corresponding outside the plane of reaction chamber about in the of 3 that what be provided with is and its size and the equal corresponding parallel plate type exciting electrode 2 of shape to connect the uniform electric field that just forms the high frequency alternation behind the high frequency electric source in the quartz reaction chamber between two parallel-plates.Under the excitation of high frequency uniform electric field, produce negative pressure plasma reaction environment.High frequency electric source is connected to high frequency voltage output on the parallel-plate electrode plate by distributing switch 1A and voltage regulator 1B.By the mass flowmenter 8A of computer control, the flow volume delivery of controlling two kinds of high-purity gas by nitrogen that designs and oxygen proportion arrives gas mixer chamber 8B, the air inlet 4A of seal closure 4 before being connected to by pipeline again, and along with fiber enters reaction chamber 3.Bleeding point 5A after the exhaust tube of vavuum pump 9 is connected on the seal closure 5 is to form 0.75-0.25 atmospheric reaction chamber subnormal ambient.Make in reacting gas to be rich in oxygen atom and oxonium ion as adding that high frequency voltage then just can produce gas ionization in reaction chamber this moment, and when its oxidability was improved, the required temperature of its pre-oxidation (and carbonization) reaction can descend greatly thereupon.Regulate the distance between two parallel-plates, and be added in voltage value between parallel plate electrode, or the equal effective and promptly required temperature in the conditioned reaction chamber of three conditions of negative pressure, thereby can very realize the temperature requirement of pre-oxidation or carbonization effectively, evidence is in 40.68 million operating frequencies, can make pre-oxidation and the required technological temperature decline 20-50% of carbonation process under the pole plate operating voltage of 200-500 volt, and shortened in the processing time greatly, and linear velocity that can corresponding quickening folding and unfolding fiber, thereby improved operating efficiency.
The folding and unfolding silk mouth (3A, 3B) of quartz reaction cavity 3 both ends of the surface of flat is long and narrow bar seam shape, is arranged on the middle part of end face, to eliminate the edge temperature error that parallel-plate electrode edge field intensity skewness forms.The advancing filament mouth (3A, 3B) and can allow passing through of 4-12 bundle pdyacrylonitril precursor of slit-shaped so that flat tow is parallel.Folding and unfolding silk wheel (6,7) and the corresponding setting of every bundle fiber before and after being in the seal closure (4,5), correspondence is set up respectively.Seal closure (4,5) also was rectangular body structure and corresponding with the bundle number of turnover before and after this just made.Flat the spreading out of every synnema passed through reaction chamber, evenly and apace contact oxonium ion, oxygen atom and oxygen molecule, thereby make reaction faster more even, rapider and thorough, reduced energy consumption, improved reaction speed, no matter to pre-oxidation or the carbonation process meaning that all has greatly improved.
After the further improvement design to reaction unit, reaction zone can suitably extend the flat reaction chamber of quartz system, and parallel-plate electrode 2 is divided into 3-6 segment structure (being three sections 2A, 2B, 2C among Fig. 2), the every pair of parallel-plate electrode can the independent regulation polar plate spacing, the every pair of parallel electrode plate is independently voltage regulator and distributing switch of correspondence all, so just can regulate the ion concentration and the reaction temperature of the pairing reaction chamber internal reaction of each segment electrode plate section respectively, thereby form a reaction environment along drawing of fiber direction uniform temperature Gradient distribution.With Fig. 2 given be example, by adjustment the technological temperature in the quartz reaction chamber 3 is formed: the even distribution of the thermograde of 300-380,380-420,420-580 to 2A, 2B, 2C three segment electrode distances between plates and operating voltage, this moment can also be further in the quartz plate reaction chamber, back segment adds high pure nitrogen and replenishes inlet (3A, 3B), with the required reaction atmosphere of adjusting carbonation stage, thereby realize pre-oxidation and carbonization step realization in a heater.
According to the set high frequency negative pressure plasma heater of above design, can adapt to each procedure of pdyacrylonitril fiber preoxidation and carbonization, can greatly reduce energy resource consumption and reaction temperature, its high efficiency, carbonization quality height, processing cost is low.Particularly under plasma environment, make the operating temperature 20-50% that descended, thereby the carbonization operating temperature near in addition be lower than the melt temperature of organic substance in the pdyacrylonitril fiber precursor, make pre-oxidation, carbonization two procedures in a heater, to realize, the quality of carbon fibre will be improved greatly, and effectively cut down finished cost, will play great impetus to the expansion of carbon fiber range of application.
Claims (10)
1, pdyacrylonitril fiber preoxidation and carbonizing new process, technical process comprises sends into pre-oxidation heating furnace through folding and unfolding silk mechanism with fiber under the drafting tension condition, be 8 less than 400 ℃ with nitrogen oxygen mixed proportion: 2-7: it is crosslinked to finish linear polymeric under 3 atmosphere, cyclisation, deoxidation, the dehydrogenation chemical reaction generates the pre-oxidation operation of the ladderlike polymer structural fibers with heat endurance and pre-oxidized fibers is sent under the drawing-off of folding and unfolding silk mechanism and charges into oxygen content in the carbonization heating furnace and be higher than under the pre-oxidation environment temperature heat treated under less than 5 milliliters/cubic metre high pure nitrogen atmosphere that pre-oxidized fibers is further taken place is crosslinked, cyclisation, polycondensation, the aromatization chemical reaction makes that carbon content reaches more than 99% in the fiber, thereby form the carbonation process of the two-dimentional carbocyclic ring plane network structure disorderly layer graphite-like structure parallel with synusia, the heating furnace that it is characterized in that in this technology being adopted is to be the negative pressure plasma heater of the energy with the high-frequency alternating current.
2, according to the said new technology of claim 1, it is characterized in that in pre-oxidation operation process environment atmosphere, containing oxygen atom and oxonium ion, its technological temperature can be controlled in 200 ℃-380 ℃.
3, according to the said new technology of claim 1, it is characterized in that in the ambiance of carbonation process, containing oxygen atom and oxonium ion, its operating temperature can be controlled in 380 ℃-680 ℃.
4,, it is characterized in that to place a step of a high frequency negative pressure plasma heater under the high frequency electric source support to finish pre-oxidation and carbonization two procedures in this new technology according to the said new technology of claim 1.
5, according to the said new technology of claim 4, it is characterized in that a technological temperature that goes on foot in the reaction chamber of finishing the used plasma heater of carbonizing new process divides three sections, the temperature range that is set to three sections by the draw fibers direction respectively is 300 ℃-380 ℃, 380 ℃-420 ℃, 420 ℃-580 ℃, realize three sections temperature gradient distribution of working environment respectively by the pairing battery lead plate driving voltage of each section and supporting parallel-plate electrode spacing adjustment, in the quartz reaction chamber, back segment replenishes high pure nitrogen.
6,, it is characterized in that said negative pressure process conditions are 0.75-0.25 atmospheric pressure according to claim 1 or 4 said new technologies.
7, the special-purpose high frequency negative pressure of pdyacrylonitril fiber preoxidation and carbonizing new process plasma heater, by high frequency electric source (1), plasma exciting electrode (2), reaction chamber (3) reach and the gas mixing device (8) of reaction chamber to being communicated with, and it is characterized in that:
The reaction chamber that a is made by quartz glass (3) is the flat cavity body, and both ends of the surface are provided with into filament mouth (3A, 3B), and seal closure (4,5) before and after disposing,
The b exciting electrode is the parallel-plate electrode (2) of the geometry corresponding with the reactor upper and lower surface,
The output of c high-frequency ac power (1) is connected on the parallel-plate electrode (2) by distributing switch (1A) and the voltage regulator (1B) that is complementary,
The mass flowmenter (8A) that d connects high pure nitrogen source and source of oxygen passes to the air inlet (4A) of preceding sealing device (4) by compounding chamber (8B) with the hybrid reaction atmosphere gas,
E vavuum pump (9) connects the gas outlet (5A) of back seal closure (5),
Also comprise the folding and unfolding silk structure (6,7) in the seal closure (4,5) before and after being located in this device of f.
8, according to the said high frequency negative pressure of claim 7 plasma heater, it is characterized in that into filament mouth (3A, 3B) is narrow seam shape, be arranged on the middle part, can hold parallel the passing through of 3-12 bundle pdyacrylonitril precursor (10), folding and unfolding silk structure (6,7) in the front and back seal closure (4,5) and the corresponding setting of tow distribution.
9, according to the high frequency negative pressure plasma heater of claim 7, it is characterized in that parallel electrode plate (2) can be divided into 3-6 section (2A, 2B, 2C) along the wire direction, but every section parallel electrode plate that forms the independent regulation polar plate spacing, the every pair of battery lead plate is connected to respectively independently on the voltage regulator and distributing switch, and the spacing between every segment electrode plate is all adjustable continuously.
10, according to the said high frequency negative pressure of claim 7 plasma heater, it is characterized in that the frequency of high frequency electric source takes 40.68 million, the adjustable range of polar plate voltage is the 300-500 volt.
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CN 02103974 CN1202297C (en) | 2002-03-05 | 2002-03-05 | New technology and device for pdyacrylonitril fiber preoxidation and carbonation |
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CN 02103974 CN1202297C (en) | 2002-03-05 | 2002-03-05 | New technology and device for pdyacrylonitril fiber preoxidation and carbonation |
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Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
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CN101260575B (en) * | 2008-04-17 | 2010-06-02 | 东华大学 | Pre-oxidation method for carbon fiber precursor polyacrylnitrile fiber |
CN103572411A (en) * | 2012-07-31 | 2014-02-12 | 金发科技股份有限公司 | Polyacrylonitrile-based carbon fibers as well as preparation method and application thereof |
CN103597130A (en) * | 2011-05-10 | 2014-02-19 | 赢创德固赛有限公司 | Method for producing carbon fibers |
WO2015012349A1 (en) * | 2013-07-26 | 2015-01-29 | 東邦テナックス株式会社 | Carbonization method and carbon fiber production method |
CN105420877A (en) * | 2015-12-22 | 2016-03-23 | 苏州协泰科技有限公司 | Nitrile group type carbon fiber precursor spinning pretreatment process |
CN105696113A (en) * | 2015-12-04 | 2016-06-22 | 江西大有科技有限公司 | Device for manufacturing carbon fibers through nonequilibrium plasma and method of device |
CN106367850A (en) * | 2016-02-22 | 2017-02-01 | 河北陆元新材料科技有限公司 | Continuous production system of polyacrylonitrile-based carbon fibers |
EP3518621A1 (en) * | 2018-01-29 | 2019-07-31 | UHT Unitech Co., Ltd | Fiber pre-oxidization device |
CN110172767A (en) * | 2019-04-11 | 2019-08-27 | 湖北枫树线业有限公司 | A kind of spinning equipment and Yarn spinning method of 1313 yarn |
CN111549522A (en) * | 2020-05-25 | 2020-08-18 | 北京化工大学 | Method for preparing polyacrylonitrile-based thermal oxidation stabilized fiber under assistance of atmospheric plasma |
CN113445156A (en) * | 2021-05-20 | 2021-09-28 | 北京化工大学 | Pre-oxidized fiber treatment device |
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2002
- 2002-03-05 CN CN 02103974 patent/CN1202297C/en not_active Expired - Fee Related
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
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CN101260575B (en) * | 2008-04-17 | 2010-06-02 | 东华大学 | Pre-oxidation method for carbon fiber precursor polyacrylnitrile fiber |
CN103597130A (en) * | 2011-05-10 | 2014-02-19 | 赢创德固赛有限公司 | Method for producing carbon fibers |
CN103572411A (en) * | 2012-07-31 | 2014-02-12 | 金发科技股份有限公司 | Polyacrylonitrile-based carbon fibers as well as preparation method and application thereof |
CN103572411B (en) * | 2012-07-31 | 2015-09-23 | 金发科技股份有限公司 | polyacrylonitrile-based carbon fibre, preparation method and application thereof |
WO2015012349A1 (en) * | 2013-07-26 | 2015-01-29 | 東邦テナックス株式会社 | Carbonization method and carbon fiber production method |
CN105264129A (en) * | 2013-07-26 | 2016-01-20 | 东邦泰纳克丝株式会社 | Carbonization method and carbon fiber production method |
US9745671B2 (en) | 2013-07-26 | 2017-08-29 | Toho Tenax Co., Ltd. | Carbonization method and carbon fiber production method |
CN105264129B (en) * | 2013-07-26 | 2018-03-30 | 东邦泰纳克丝株式会社 | The manufacture method of carbonization method and carbon fiber |
CN105696113B (en) * | 2015-12-04 | 2018-06-26 | 江西大有科技有限公司 | A kind of devices and methods therefor using nonequilibrium plasma manufacture carbon fiber |
CN105696113A (en) * | 2015-12-04 | 2016-06-22 | 江西大有科技有限公司 | Device for manufacturing carbon fibers through nonequilibrium plasma and method of device |
CN105420877A (en) * | 2015-12-22 | 2016-03-23 | 苏州协泰科技有限公司 | Nitrile group type carbon fiber precursor spinning pretreatment process |
CN106367850A (en) * | 2016-02-22 | 2017-02-01 | 河北陆元新材料科技有限公司 | Continuous production system of polyacrylonitrile-based carbon fibers |
CN106367850B (en) * | 2016-02-22 | 2018-09-25 | 河北陆元新材料科技有限公司 | A kind of continuous production system of polyacrylonitrile-based carbon fibre |
EP3518621A1 (en) * | 2018-01-29 | 2019-07-31 | UHT Unitech Co., Ltd | Fiber pre-oxidization device |
CN110172767A (en) * | 2019-04-11 | 2019-08-27 | 湖北枫树线业有限公司 | A kind of spinning equipment and Yarn spinning method of 1313 yarn |
CN110172767B (en) * | 2019-04-11 | 2020-10-13 | 湖北枫树线业有限公司 | 1313 yarn spinning equipment and spinning method |
CN111549522A (en) * | 2020-05-25 | 2020-08-18 | 北京化工大学 | Method for preparing polyacrylonitrile-based thermal oxidation stabilized fiber under assistance of atmospheric plasma |
CN113445156A (en) * | 2021-05-20 | 2021-09-28 | 北京化工大学 | Pre-oxidized fiber treatment device |
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