CN118166458A

CN118166458A - Method for loading in process of preparing carbon fiber from twisted polyacrylonitrile fiber

Info

Publication number: CN118166458A
Application number: CN202410351678.8A
Authority: CN
Inventors: 王思思; 王达凯; 李军; 郝雁彬; 杜晓敏; 王敬华; 高鹏
Original assignee: Shanxi Gangke Carbon Materials Co Ltd
Current assignee: Shanxi Gangke Carbon Materials Co Ltd
Priority date: 2024-03-26
Filing date: 2024-03-26
Publication date: 2024-06-11

Abstract

The invention provides a method for loading a twisted polyacrylonitrile fiber into a carbon fiber, which relates to the technical field of carbon fibers and comprises a starting step and an oxidizing furnace penetrating step; in the step of starting the vehicle: setting a transmission speed and the draft ratio of the No. 1-n oxidation furnace to the filament bundles, starting transmission equipment, and starting twisting equipment; the twisted filament bundle enters a No. 1 oxidation furnace to start passing through the oxidation furnace after being divided. Twisting immediately after starting transmission, adding a wire dividing comb, twisting to enable single-bundle fibers to generate inclined spiral wire turns, forming a compact structure which is not easy to damage transversely, reducing the uneven intensity rate, and tightly cohesion of monofilaments can also reduce the phenomenon of hair generation of the tows; the wire dividing comb can reduce the accident of broken wire winding caused by winding adjacent tows together, so that the times of broken wires and winding are reduced, the time of the operation of putting the wire on the frame is shortened, and the production efficiency is improved.

Description

Method for loading in process of preparing carbon fiber from twisted polyacrylonitrile fiber

Technical Field

The invention relates to the technical field of carbon fibers, in particular to a method for putting on a frame in the process of preparing carbon fibers from twisted polyacrylonitrile fibers.

Background

The polyacrylonitrile-based carbon fiber (namely, precursor) can be obtained by the processes of pre-oxidation, low-temperature carbonization, high-temperature carbonization, surface treatment and the like. When the production is started, the precursor is required to pass through an oxidation furnace, a low-temperature carbonization furnace, a high-temperature carbonization furnace, a surface treatment tank and the like in sequence according to stations until reaching a filament receiving machine, and is rolled into a carbon fiber finished product, and the process is called as 'putting on shelf' operation. In the process, the consumption of auxiliary materials and energy sources is basically the same as that in normal production, but no finished product is produced, so that the time for loading the auxiliary materials and the energy sources is required to be shortened.

In the process of loading, the starting is in a mode of dividing wires after starting transmission, then lapping a dividing wire grate and finally starting the twisting machine.

However, the specification of twisted carbon fibers is generally 1K and 3K, the hair of the tows is serious, and the twisted fibers are in a spinning state, so that adjacent tows are easily wound together by adopting the existing starting mode, thereby leading to serial positions and broken filaments, the time for processing broken filaments is wasted, the production efficiency is reduced, particularly in an oxidation section, the multi-layer fibers need to pass through a plurality of furnace bodies, the multi-layer fibers reciprocate, accidents such as broken filaments and winding rollers are more likely to happen, but because the space is relatively narrow, more time is required for processing the accidents, the operation between rotating driving rollers also brings great safety risks, and the waste of energy materials is also caused.

Disclosure of Invention

Therefore, the invention provides a method for loading operation in the process of preparing carbon fibers from twisted polyacrylonitrile fibers, which aims to solve the problem of prolonged loading time caused by an oxidation section Yi Duansi and a winding roller in the prior art.

In order to solve the problems, the invention provides a method for loading a twisted polyacrylonitrile fiber into a carbon fiber, which comprises a starting step and an oxidizing furnace penetrating step;

In the step of starting the vehicle: setting a transmission speed and the draft ratio of the No. 1-n oxidation furnace to the filament bundles, starting transmission equipment, and starting twisting equipment;

After the twisted filament bundle is divided, the filament bundle enters a No. 1 oxidation furnace to start passing through the oxidation furnace.

In some embodiments, the inlet of the oxidation furnace No.1 is provided with a yarn dividing device for performing auxiliary yarn dividing.

In some embodiments, the outlet of the number 1 oxidation oven, the inlet of the number 2 to n oxidation ovens, and the outlet are each equipped with a filament dividing device to maintain the filament bundle in a divided state;

preferably, the filament dividing device is a filament dividing grate.

In some embodiments, in the step of starting the vehicle: the twist of the twisting equipment is set to be 10-50%; wherein x is the process twist.

In some embodiments, the initial draft ratio of the No. 1-n oxidation furnace to the filament bundles is set to be-1%; when the filament bundle connector is out of the m-number oxidizing furnace, setting the drawing multiplying power of the m-number oxidizing furnace on the filament bundle as the process drawing multiplying power, wherein m is more than or equal to 1 and less than or equal to n;

Preferably, the drawing ratio of the m-number oxidation furnace to the filament bundle is kept to be the initial drawing ratio when the filament bundle connector is arranged in the m-number oxidation furnace.

In some embodiments, the heat preservation temperature of the oxidation furnace 1-n is set to 50-150 ℃ before the starting step; and/or

When the tow joint runs to one of the 3 layers of the reciprocal of the m-number oxidizing furnace, the temperature of the m-number oxidizing furnace is set as the process temperature.

In some embodiments, in the step of starting the vehicle, the initial transmission speed of the transmission device is set to be 50-200 m/h; when the filament bundle connector is out of the No. 1 oxidation furnace, the transmission speed is increased to 50% -75% of the process transmission speed value; after the tow is spliced out of the No. 4 oxidation oven, the transmission speed is increased to a process transmission speed value.

In some embodiments, the racking operation method further comprises a carbonization furnace passing step; the carbonization furnace penetrating step comprises a low-temperature carbonization furnace penetrating step and a high-temperature carbonization furnace penetrating step;

before the step of passing through the low-temperature carbonization furnace, checking pre-buried carbon wires of the low-temperature carbonization furnace, and after the wire bundle joints are all out of the last oxidation furnace and the state of the pre-oxidized wires is a set state, starting to pass through the low-temperature carbonization furnace; the set state is a state that the color is black and bright and the hand feeling is moist;

Preferably, in the step of passing through the low-temperature carbonization furnace, the drawing ratio of the low-temperature carbonization furnace to the filament bundle is set to be a process value of +0.3% -process value of +0.5%.

In some embodiments, the step of passing through a high temperature carbonization furnace further comprises a surface treatment step.

In some embodiments, the method further comprises a preparation step prior to the start-up step; wherein the preparing step includes:

Heating a low-temperature carbonization furnace and a high-temperature carbonization furnace; and/or

Preparing electrolyte, water washing liquid and sizing liquid required by the surface treatment step; and/or

And feeding the polyacrylonitrile fiber required by production to a filament drawing machine according to a station.

The invention provides a method for putting on a frame in the process of preparing carbon fibers from twisted polyacrylonitrile fibers, which has the following beneficial effects compared with the prior art:

1. According to the invention, the machine is started in the modes of transmission starting, twisting and filament splitting, and immediately twisting is performed after the transmission is started, and filament splitting is performed through filament splitting equipment, so that single-bundle fibers are twisted to form inclined spiral line turns, a compact structure which is not easy to damage transversely is formed, the strength unevenness is reduced, and the phenomenon of hair generation of the filament bundles can be reduced due to the tight cohesion of the filaments; the wire dividing comb can reduce the accident of broken wire winding caused by winding adjacent tows together, so that the times of broken wires and winding are reduced, the time of the operation of putting the wire on the frame is shortened, and the production efficiency is improved.

2. The twist is reduced to 10% -50% of the technical twist during twisting, so that the rotation of the precursor ingot is slow, and the safety risk of operators in the operation of a yarn withdrawal area is reduced.

3. In the step of passing through the low-temperature carbonization furnace, the drawing multiplying power of the low-temperature carbonization furnace on the filament bundle is adjusted to reduce the phenomenon of winding rollers at an oxidation section and reduce the retention of broken filaments in the furnace body. Because the temperature in the low-temperature carbonization furnace is higher, the fiber decomposition reaction is severe and is the position which is most easy to break the fiber, when the filament bundle connector enters the low-temperature carbonization furnace in the process of putting on a frame, part of the fiber (filament bundle) is still in the oxidation furnace, and the shrinkage rate of the pre-oxidized fiber is inconsistent due to unstable oxidation temperature and process atmosphere in the furnace body, so that the drawing rate of the low-temperature carbonization section is improved to maintain the tension of the fiber in the oxidation furnace, thereby reducing the winding roll caused by the shrinkage of the pre-oxidized fiber.

4. The transmission speed is gradually increased from low to high, so that the reaction process of the filament bundles is slowed down, the operation process is more stable, the probability of filament breakage is reduced, and broken filaments generated during repeated furnace penetration are reduced to be detained in the worn fibers of the furnace body, thereby avoiding blocking waste discharge pipelines and continuously influencing the quality of carbon fibers. The operation speed is low, so that an operator can conveniently process broken wires, and the safety risk is reduced.

5. The initial draft of the oxidation section to the filament bundle is set to be-1% (the draft of the oxidation section to the filament bundle is positive draft in the normal running state), the fiber tension is not excessive, the fiber is prevented from being stretched, and the following needs to be noted: when the spinneret is in the oxidation furnace, the operator cannot observe the running state of the spinneret, and oxidation draft is forbidden to be changed at the moment, so that the situation that the spinneret is broken due to draft mutation can be reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. The drawings in the following description are merely exemplary and other implementations drawings may be derived from the drawings provided without inventive effort for a person skilled in the art.

Fig. 1 is a flow chart of the tow operation throughout the racking operation.

Detailed Description

The invention provides a method for loading a twisted polyacrylonitrile fiber into a carbon fiber, which comprises a starting step and an oxidizing furnace penetrating step;

The twisted filament bundle is divided into filaments and enters a No. 1 oxidation furnace to start passing through the oxidation furnace.

Further, a yarn separating device is arranged at the inlet of the No.1 oxidation furnace and used for auxiliary yarn separation.

Further, the outlet of the No. 1 oxidation furnace, the inlets and the outlets of the No. 2-n oxidation furnaces are all provided with filament dividing equipment so as to keep filament bundles in filament dividing states;

preferably, the filament dividing device is a filament dividing grate.

In the method, the machine is started in the modes of transmission starting, twisting and filament splitting, and immediately twisting and filament splitting are carried out through filament splitting equipment after transmission starting, so that single-bundle fibers are twisted to form inclined spiral lines, a compact structure which is not easy to damage transversely is formed, the strength unevenness is reduced, and the phenomenon of hair generation of the filament bundles can be reduced due to the compact cohesion of the filaments; the wire dividing comb can reduce the accident of broken wire winding caused by winding adjacent tows together, so that the times of broken wires and winding are reduced, the time of the operation of putting the wire on the frame is shortened, and the production efficiency is improved.

Further, in the step of starting the vehicle: the twist of the twisting equipment is set to be 10-50%; wherein x is the process twist, the twist is reduced to 10% -50% of the process twist, so that the precursor ingot rotates slowly, and the safety risk of operators in the yarn unwinding area is reduced.

Further, the initial draft ratio of the No. 1-n oxidation furnace to the filament bundles is set to be-1%; when the filament bundle connector is out of the m-number oxidizing furnace, setting the drawing multiplying power of the m-number oxidizing furnace on the filament bundle as the process drawing multiplying power, wherein m is more than or equal to 1 and less than or equal to n; the initial draft of the oxidation section is set to be-1% (the draft of the oxidation section is positive draft under the normal running state), so that the tension of the fiber is not excessive, and the fiber is prevented from being stretched;

Preferably, when the filament bundle connector is arranged in the m-number oxidizing furnace, the draft ratio of the m-number oxidizing furnace to the filament bundle is kept unchanged (namely still is the initial draft ratio), so that the situation that the filament bundle is broken due to the abrupt draft can be reduced.

Further, before the step of starting the vehicle, the heat preservation temperature of the No. 1-n oxidation furnaces is set to be 50-150 ℃; when the filament bundle connector moves to one of 3 layers of the reciprocal of each oxidation furnace, the filament bundle connector is connected with the main control, so that the oxidation furnaces start to heat to the process temperature (generally 200-300 ℃), filament separation and heating are realized, heating time is saved, and the time of the operation of putting the filament bundle connector on a rack is shortened.

Further, in the step of starting the vehicle, the initial transmission speed of the transmission equipment is set to be 50-200 m/h; when the filament bundle connector is out of the No. 1 oxidation furnace, the transmission speed is increased to 50% -75% of the process transmission speed value; when the filament bundle connector is out of the No. 4 oxidation furnace, the transmission speed is increased to a process transmission speed value; the transmission speed is gradually increased from low to high, so that the reaction process of the filament bundle is slowed down, the operation process is more stable, the probability of filament breakage is reduced, an operator is convenient to process the filament breakage, and the broken filaments are reduced to stay in the furnace body.

Further, the racking operation method further comprises a carbonization furnace penetrating step; the carbonization furnace penetrating step comprises a low-temperature carbonization furnace penetrating step and a high-temperature carbonization furnace penetrating step;

Preferably, in the step of passing through the low-temperature carbonization furnace, the drawing ratio of the low-temperature carbonization furnace to the filament bundle is set to be a process value of +0.3% -process value of +0.5%, and the drawing ratio of the low-temperature carbonization furnace to the filament bundle is adjusted to be high, so that the phenomenon of winding rollers at an oxidation section can be reduced, and the broken filaments are retained in the furnace body. Because the temperature in the low-temperature carbonization furnace is higher, the fiber decomposition reaction is severe and is the position which is most easy to break the filament, and in the process of putting on the frame, the shrinkage rate of the pre-oxidized filament is inconsistent because the oxidation temperature and the process atmosphere in the furnace body are unstable, the drafting of the low-temperature carbonization section is improved, and the winding roll caused by the retraction of the pre-oxidized filament can be lightened.

Further, the high-temperature carbonization furnace penetrating step further comprises a surface treatment step.

Further, the method further comprises a preparation step before the starting step; wherein the preparation step comprises the following steps:

The technological value, the technological twist, the technological temperature, the technological draft ratio, the technological transmission speed and the like are all technological requirement values, namely the basic requirement values for completing the racking operation method are a set of curing standard values summarized and summarized by technicians for a long time, and products with different specifications correspond to a set of technological parameter control range. The technological requirement value is generally programmed into technological rules for setting and operation by post personnel.

The invention is further illustrated by the following specific examples:

Example 1

The embodiment provides a method for putting on a frame in the process of preparing carbon fibers from twisted polyacrylonitrile fibers, which specifically comprises the following steps:

The preparation steps are as follows: heating a low-temperature carbonization furnace and a high-temperature carbonization furnace, preparing electrolyte, water washing liquid and sizing liquid required by a surface treatment procedure in the process, and feeding polyacrylonitrile fibers required by production to a filament drawing machine according to stations. The fiber is connected with the reserved fiber single-to-single joint in the oxidation furnace. The temperature of the oxidation furnace is set to be 150 ℃ for heat preservation.

And (3) starting a vehicle: the draft ratio of the No. 1-6 oxidation furnace to the filament bundle is set to be-0.5%, the transmission speed is set to be 150m/h, the transmission equipment is started, the twisting machine is started, and the motor frequency of the twisting machine is adjusted to be 50% of the technical twist. And a wire dividing grate is arranged at the outlet and the inlet of the No. 1-6 oxidation furnace.

Passing through an oxidation furnace: beating a full-station weft yarn (used for dividing silk bundles) in front of an inlet of a No. 1 oxidation furnace, pulling the weft yarn by two persons in front of a silk dividing grate, and cutting the weft yarn after the stations are all aligned; the filament bundle enters the No. 1 oxidation furnaces after passing through the filament-stripping machine, the twisting machine, the weft and the filament-dividing grate, when the filament bundle is connected to the 3 rd layer of each oxidation furnace, the filament bundle is connected with the main control, and the oxidation furnaces start to be heated to the target process temperature. And after the filament bundle joint is discharged from the No. 1 oxidation furnace, the transmission speed is increased to 70% of the process transmission speed value, and the transmission draft ratio of the No. 1 oxidation furnace is restored to the process draft ratio value. A full-station weft yarn is beaten in front of the inlet of the No. 2 oxidation furnace, the same operation is performed until the No. 6 oxidation furnace. It should be noted that the spinneret (i.e., the filament bundle connector) prohibits changing the oxidative draft while in the oxidation oven. Finally, whether the split yarn is correct or not is checked, and the yarn bundle with the combined yarn is observed from the outlet of the oxidizing furnace from the No. 1 furnace, is poked into an adjacent station, and the fiber can be automatically separated according to the tension and then is put into the groove according to the path of the yarn bundle. The yarn dividing mode is convenient and quick. ( The method for beating up the weft comprises the following steps: one end of the weft thread sequentially passes through the tows of the interval station, and the other end of the weft thread sequentially passes through the tows of the interval station (staggered with the weft thread which is firstly beaten by one station). After the weft is beaten up, the weft is lifted slightly to confirm whether each tow is in the weft, if all tows are in the same horizontal position, indicating that all tows are in the weft. Knotting two ends of the weft. )

After the spinneret is completely discharged from the last oxidation furnace, the transmission speed is set as a process transmission speed value. The draft ratio of the low-temperature carbonization furnace to the filament bundle is set to be a process value of +0.3%.

Passing through a carbonization furnace: before the carbon fiber passes through the low-temperature carbonization furnace and the high-temperature carbonization furnace, whether the pre-buried carbon fiber is good or not is confirmed, and whether the furnace pressure reaches the micro-positive pressure state or not is confirmed. The slight color change of the pre-oxidized fiber was observed: dark brown black-bright black (moistures) -black (hair shafts), when the tows become black and bright and the hand feel moistures (beginners can know that the lighter can not be used for burning the pre-oxidized fibers, and the state of non-melting and non-combustibility can be achieved), the tows start to pass through the low-temperature carbonization furnace, and the success of one-time furnace passing can be basically ensured. The operation of the step must grasp the state of quasi-pre-oxidized wires, grasp the quasi-furnace penetrating time, the pre-oxidation degree is insufficient, and the wires are easy to break in a low-temperature carbonization furnace; the filament bundle is easy to wind around the roller when peroxidized.

And (3) surface treatment: the tows at the surface treatment section are easy to wind due to wetting and stickiness, so that the inspection frequency is increased, and the tows are dispersed in time, so that the tows are dried and prevented from winding;

the yarn is separated to the last driving roller, the full-station weft is not removed, two ends of the weft are hung at the outlet of the drying furnace, so that the yarn bundles can be automatically separated, and the friction force between the yarn bundles and the roller surface is large because the yarn bundles are not completely dried at the moment, and the attention is paid to the fact that the wire drawing force cannot be too large, so that the winding of the roller and the damage to equipment are avoided.

After all the fibers are put on a silk winding machine, the twist of the twisting machine is restored to a process twist value, and the draft ratio of the low-temperature carbonization furnace to the silk bundle is restored to the process value. So far, the racking operation is finished, and normal production is started.

The operation flow of the filament bundle in the racking operation is shown in figure 1, the filament bundle enters a No. 1 oxidation furnace after passing through a filament-stripping machine, a twisting machine, a weft and a filament-dividing grate, is pre-oxidized in the No. 1 oxidation furnace, enters a No. 2 oxidation furnace after passing through the filament-dividing grate, the weft and the filament-dividing grate, is … … until oxidized in a No. n oxidation furnace, passes through the filament-dividing grate, passes through a carbonization furnace and is subjected to surface treatment, and finally enters a filament-collecting machine.

In the embodiment, the time length of the racking operation is 8.3 hours, and the wire is broken 1 time and the roller is wound 2 times in the racking process.

Example two

The preparation steps are as follows: heating a low-temperature carbonization furnace and a high-temperature carbonization furnace, preparing electrolyte, water washing liquid and sizing liquid required by a surface treatment procedure in the process, and feeding polyacrylonitrile fibers required by production to a filament drawing machine according to stations. The fiber is connected with the reserved fiber single-to-single joint in the oxidation furnace. The temperature of the oxidation furnace is set to 160 ℃ for heat preservation.

And (3) starting a vehicle: setting the draft ratio of the No. 1-5 oxidation furnace to the filament bundle to be 0.5%, setting the transmission speed to be 160m/h, starting the transmission equipment, starting the twisting machine, and adjusting the motor frequency of the twisting machine to be 1/2 of the set twist. And a wire dividing grate is arranged at the outlet and the inlet of the No. 1-5 oxidation furnace.

Passing through an oxidation furnace: beating a full-station weft yarn in front of an inlet of a No. 1 oxidation furnace, pulling the weft yarn by two persons in front of a wire dividing grate, and cutting the weft yarn after the stations are all aligned; the filament bundle enters the No. 1 oxidation furnace after passing through the filament withdrawing machine, the twisting machine, the weft and the filament dividing grate, and when the filament bundle is connected to the layer 2 of the reciprocal of the oxidation furnace, the filament bundle is communicated with the main control and the oxidation furnace starts to be heated to the target process temperature. And (3) increasing the transmission speed of the spinneret after the spinneret is discharged from the No. 1 oxidation furnace to 75% of the process transmission speed value, and recovering the transmission draft ratio of the No. 1 oxidation furnace to the process draft ratio value. A full-station weft yarn is beaten in front of the inlet of the No. 2 oxidation furnace, the same operation is performed until the No. 5 oxidation furnace. It should be noted that the spinneret prohibits changing the oxidative draft while in the oxidation oven. Finally, whether the split yarn is correct or not is checked, and the yarn bundle with the combined yarn is observed from the outlet of the oxidizing furnace from the No. 1 furnace, is poked into an adjacent station, and the fiber can be automatically separated according to the tension and then is put into the groove according to the path of the yarn bundle. The yarn dividing mode is convenient and quick. ( The method for beating up the weft comprises the following steps: one end of the weft thread sequentially passes through the tows of the interval station, and the other end of the weft thread sequentially passes through the tows of the interval station (staggered with the weft thread which is firstly beaten by one station). After the weft is beaten up, the weft is lifted slightly to confirm whether each tow is in the weft, if all tows are in the same horizontal position, indicating that all tows are in the weft. Knotting two ends of the weft. )

After the spinneret is completely discharged from the last oxidation furnace, the transmission speed is set as a process transmission speed value. The draft ratio of the low-temperature carbonization furnace is set to be a process value of +0.4%. The spinneret exits an oxidation oven that begins to warm up toward a target temperature.

And (3) surface treatment: the tows at the surface treatment section are easy to wind due to wetting and stickiness, so that the inspection frequency is increased, and the tows are dispersed in time, so that the tows are dried, and the winding of the rollers is prevented.

In the embodiment, the time length of the racking operation is 7.6 hours, the wire is broken 2 times in the racking process, and the roller is wound 1 time.

Embodiment III:

The preparation steps are as follows: heating a low-temperature carbonization furnace and a high-temperature carbonization furnace, preparing electrolyte, water washing liquid and sizing liquid required by a surface treatment procedure in the process, and feeding polyacrylonitrile fibers required by production to a filament drawing machine according to stations. The fiber is connected with the reserved fiber single-to-single joint in the oxidation furnace. The temperature of the oxidation furnace is set to 180 ℃ for heat preservation.

And (3) starting a vehicle: setting the draft ratio of the No. 1-4 oxidation furnace to the filament bundle to be 0%, setting the transmission speed to be 180m/h, starting the transmission equipment, starting the twisting machine, adjusting the motor frequency of the twisting machine to be 1/2 of the set twist, and arranging a filament dividing grate at the outlet and the inlet of the No. 1-4 oxidation furnace.

Passing through an oxidation furnace: beating a full-station weft yarn in front of an inlet of a No. 1 oxidation furnace, pulling the weft yarn by two persons in front of a wire dividing grate, and cutting the weft yarn after the stations are all aligned; the filament bundle enters the No. 1 oxidation furnace after passing through the filament withdrawing machine, the twisting machine, the weft and the filament dividing grate, and when the filament bundle is connected to the layer 1 of the reciprocal of the oxidation furnace, the filament bundle is connected with the main control, and the oxidation furnace is heated to the target process temperature. And (3) increasing the transmission speed of the spinneret after the spinneret is discharged from the No. 1 oxidation furnace to 70% of the process transmission speed value, and recovering the transmission draft ratio of the No. 1 oxidation furnace to the process draft ratio value. A full-station weft yarn is beaten in front of the inlet of the No. 2 oxidation furnace, the same operation is performed and so on until the No. 4 oxidation furnace. It should be noted that the spinneret prohibits changing the oxidative draft while in the oxidation oven. Finally, whether the split yarn is correct or not is checked, and the yarn bundle with the combined yarn is observed from the outlet of the oxidizing furnace from the No. 1 furnace, is poked into an adjacent station, and the fiber can be automatically separated according to the tension and then is put into the groove according to the path of the yarn bundle. The yarn dividing mode is convenient and quick. ( The method for beating up the weft comprises the following steps: one end of the weft thread sequentially passes through the tows of the interval station, and the other end of the weft thread sequentially passes through the tows of the interval station (staggered with the weft thread which is firstly beaten by one station). After the weft is beaten up, the weft is lifted slightly to confirm whether each tow is in the weft, if all tows are in the same horizontal position, indicating that all tows are in the weft. Knotting two ends of the weft. )

After the spinneret is completely discharged from the last oxidation furnace, the transmission speed is set as a process transmission speed value. The draft ratio of the low-temperature carbonization furnace to the filament bundle is set to be a process value of +0.5%. The spinneret exits an oxidation oven that begins to warm up toward a target temperature.

In the embodiment, the time length of the racking operation is 6.9 hours, the wire is broken 0 times in the racking process, and the roller is wound 0 times.

Comparative example one

The comparative example provides a method for putting on a frame in the process of preparing carbon fibers from twisted polyacrylonitrile fibers, which specifically comprises the following steps:

The transmission speed and the draft ratio of the oxidation section are corresponding process values, and the transmission equipment is started.

Passing through an oxidation furnace: beating a full-station weft yarn (for dividing tows) in front of an inlet of a No. 1 oxidation furnace (beating-up method comprises the steps of sequentially passing one end of the weft yarn through tows of an interval station, sequentially passing the other end of the weft yarn through tows of the interval station (staggered with the previously beaten weft yarn by one station), slightly lifting the weft yarn after the weft yarn is beaten up to confirm whether each bundle of yarns is in the weft yarn, and knotting two ends of the weft yarn if all tows are in the same horizontal position, namely, pulling the weft yarn by two persons at an outlet of the No. 1 oxidation furnace, and cutting the weft yarn after the stations are all put into positions; when the wires are separated to the layer 3 of the reciprocal of the oxidation furnace, the oxidation furnace is connected with the main control and starts to heat up to the target process temperature. A full-station weft yarn is beaten in front of the inlet of the No. 2 oxidation furnace, the same operation is performed until the No. 6 oxidation furnace. And finally checking whether the parting line is correct.

After all the fibers are put on a silk collecting machine, a silk dividing grate is put on, a twisting machine is started (twisting starts to be carried out), and the twist is a process set twist value. The fiber on each station is wound on the paper tube of the silk collecting machine to start winding, and the operation of putting on the frame is finished.

In this comparative example, the length of the racking operation was 15.2 hours, the wire was broken 11 times during the racking process, and the roller was wound 8 times.

Technical effects and analysis: the first comparative example adopts the existing starting sequence to put on the frame, namely adopts the mode of dividing wires after starting transmission, then lapping a dividing wire grate and finally starting a twisting machine, and compared with the first embodiment, the method has the advantages that the time length of putting on the frame is longer, the number of broken wires and winding rollers is more, because the oxidation section process is usually a plurality of furnace bodies, the multi-layer fiber runs back and forth, the space is relatively narrow, accidents such as broken wires and winding rollers are more difficult to treat than other processes, and the treatment time is longer; the single-strand fiber is twisted to form an inclined spiral line, so that a compact structure which is not easy to be damaged transversely is formed, the strength unevenness is reduced, and the phenomenon of hair generation of the single-strand fiber can be reduced by tightly cohesion of the single-strand fiber; the added dividing grate can better reduce the accident of broken silk and winding roller caused by winding adjacent silk bundles together.

Comparative example two

And (3) starting a vehicle: setting the draft ratio of the No. 1-5 oxidation furnace to the filament bundle to be 0%, setting the transmission speed to be 160m/h, starting the transmission equipment, starting the twisting machine, adjusting the motor frequency of the twisting machine to be 1/2 of the technical twist, and arranging a filament dividing grate at the outlet and the inlet of the No. 1-5 oxidation furnace.

Passing through an oxidation furnace: beating a full-station weft yarn in front of an inlet of a No. 1 oxidation furnace, pulling the weft yarn by two persons in front of a wire dividing grate, and cutting the weft yarn after the stations are all aligned; the filament bundle enters the No. 1 oxidation furnace after passing through the filament withdrawing machine, the twisting machine, the weft and the filament dividing grate, and when the filament is divided to the layer 2 of the reciprocal of the oxidation furnace, the filament bundle is communicated with the main control, and the oxidation furnace starts to be heated to the target process temperature. And (3) increasing the transmission speed of the spinneret after the spinneret is discharged from the No. 1 oxidation furnace to 75% of the process transmission speed value, and recovering the transmission draft ratio of the No. 1 oxidation furnace to the process draft ratio value. A full-station weft yarn is beaten in front of the inlet of the No. 2 oxidation furnace, the same operation is performed until the No. 5 oxidation furnace. It should be noted that the spinneret prohibits changing the oxidative draft while in the oxidation oven. Finally, whether the split yarn is correct or not is checked, and the yarn bundle with the combined yarn is observed from the outlet of the oxidizing furnace from the No. 1 furnace, is poked into an adjacent station, and the fiber can be automatically separated according to the tension and then is put into the groove according to the path of the yarn bundle. The yarn dividing mode is convenient and quick. ( The method for beating up the weft comprises the following steps: one end of the weft thread sequentially passes through the tows of the interval station, and the other end of the weft thread sequentially passes through the tows of the interval station (staggered with the weft thread which is firstly beaten by one station). After the weft is beaten up, the weft is lifted slightly to confirm whether each tow is in the weft, if all tows are in the same horizontal position, indicating that all tows are in the weft. Knotting two ends of the weft. )

After the spinneret is completely discharged from the last oxidation furnace, the transmission speed is set as a process transmission speed value. The drawing ratio of the low-temperature carbonization furnace to the filament bundle is set as a process value.

After all the fibers are put on a silk winding machine, the twist of the twisting machine is restored to a process twist value, and the low-carbon drafting is restored to the process value. So far, the racking operation is finished, and normal production is started.

In this comparative example, the length of the racking operation was 12.7 hours, the wire was broken 12 times during the racking process, and the roller was wound 7 times.

Technical effects and analysis: in the second comparative example, compared with the second comparative example, the drawing ratio of the low-temperature carbonization furnace to the filament bundle is not increased, so that the fiber in the oxidation section is retracted, the winding roller is formed for 7 times, and the shelf time is prolonged. The method is characterized in that the temperature in the low-temperature carbonization furnace is higher, the fiber decomposition reaction is severe, the fiber breakage is the position which is most easy to occur, and in the process of putting the fiber into a frame, the shrinkage rate of the pre-oxidized fiber is inconsistent due to unstable oxidizing temperature and process atmosphere in the furnace body, so that the drafting of the low-carbon section is properly improved, and the winding roll caused by the retraction of the pre-oxidized fiber can be reduced.

Comparative example three

And (3) starting a vehicle: setting the draft ratio of the No. 1-4 oxidation furnace to the filament bundle to be 0%, setting the transmission speed to be 320m/h (process transmission speed value), starting the transmission equipment, starting the twisting machine, and adjusting the motor frequency of the twisting machine to be 1/2 of the set twist. And a wire dividing grate is arranged at the outlet and the inlet of the No. 1-4 oxidation furnace.

Passing through an oxidation furnace: beating a full-station weft yarn in front of an inlet of a No. 1 oxidation furnace, pulling the weft yarn by two persons in front of a wire dividing grate, and cutting the weft yarn after the stations are all aligned; the filament bundle enters the No. 1 oxidation furnace after passing through the filament withdrawing machine, the twisting machine, the weft and the filament dividing grate, and when the filament is divided to the layer 1 of the reciprocal of the oxidation furnace, the filament bundle is communicated with the main control, and the oxidation furnace starts to be heated to the target process temperature. And (5) recovering the transmission draft ratio of the No. 1 oxidation furnace to the process draft ratio value after the spinneret is discharged from the No. 1 oxidation furnace. A full-station weft yarn is beaten in front of the inlet of the No. 2 oxidation furnace, the same operation is performed and so on until the No. 4 oxidation furnace. It should be noted that the spinneret prohibits changing the oxidative draft while in the oxidation oven. Finally, whether the split yarn is correct or not is checked, and the yarn bundle with the combined yarn is observed from the outlet of the oxidizing furnace from the No. 1 furnace, is poked into an adjacent station, and the fiber can be automatically separated according to the tension and then is put into the groove according to the path of the yarn bundle. The yarn dividing mode is convenient and quick. ( The method for beating up the weft comprises the following steps: one end of the weft thread sequentially passes through the tows of the interval station, and the other end of the weft thread sequentially passes through the tows of the interval station (staggered with the weft thread which is firstly beaten by one station). After the weft is beaten up, the weft is lifted slightly to confirm whether each tow is in the weft, if all tows are in the same horizontal position, indicating that all tows are in the weft. Knotting two ends of the weft. )

After the spinneret was completely discharged from the last oxidation oven, the draft ratio of the low-temperature carbonization oven was set to be +0.5%.

In this comparative example, the length of the racking operation was 13 hours, the wire was broken 7 times during the racking process, and the roller was wound 6 times.

Technical effects and analysis:

Compared with the three phases of the embodiment, the transmission speed is directly the transmission speed value of the process, rather than gradually increasing from small to large, the number of filament breakage and winding times in the process of putting on the frame is more, the transmission speed is high, the operation difficulty of personnel in handling filament breakage and splitting is also increased, and the final putting on frame time is prolonged to 13 hours. The device is characterized in that the transmission speed is high, the tows are not completely split in the process of putting the device on the frame, partial tows are incomplete in reaction, weak knots exist, the probability of broken yarn winding is increased due to instability in the operation process, the oxidized section tows are in multi-layer round-trip operation, the operation space is narrow, the difficulty of personnel processing broken yarn winding is high, and the processing difficulty of personnel is further increased due to high speed.

Comparative example four

The draft ratio of the No. 1-6 oxidation furnace to the filament bundle is set to be 0%, the transmission speed is set to be 150m/h, and the transmission equipment is started.

Passing through an oxidation furnace: beating a full-station weft yarn in front of an inlet of a No. 1 oxidation furnace, pulling the weft yarn by two persons in front of a wire dividing grate, and cutting the weft yarn after the stations are all aligned; the filament bundle enters the No. 1 oxidation furnace after passing through the filament withdrawing machine, the twisting machine, the weft and the filament dividing grate, and when the filament is divided to the layer 3 of the reciprocal of the oxidation furnace, the filament bundle is communicated with the main control, and the oxidation furnace starts to be heated to the target process temperature. And (3) increasing the transmission speed of the spinneret after the spinneret is discharged from the No. 1 oxidation furnace to 70% of the process transmission speed value, and recovering the transmission draft ratio of the No. 1 oxidation furnace to the process value. A full-station weft yarn is beaten in front of the inlet of the No. 2 oxidation furnace, the same operation is performed until the No. 6 oxidation furnace. It should be noted that the spinneret prohibits changing the oxidative draft while in the oxidation oven. Finally, whether the split yarn is correct or not is checked, and the yarn bundle with the combined yarn is observed from the outlet of the oxidizing furnace from the No. 1 furnace, is poked into an adjacent station, and the fiber can be automatically separated according to the tension and then is put into the groove according to the path of the yarn bundle. The yarn dividing mode is convenient and quick. The method for beating up the weft comprises the steps of firstly enabling one end of the weft to sequentially pass through tows of an interval station, then enabling the other end of the weft to sequentially pass through tows of the interval station (staggered with the weft to be beaten first by one station), slightly lifting the weft after the weft is beaten up to confirm whether each tow of silk is in the weft or not, and if all tows are in the same horizontal position, indicating that all tows are in the weft silk, knotting two ends of the weft, namely, lapping the silk grate after the oxidation section silk splitting is completed.

After the spinneret is completely discharged from the last oxidation furnace, the transmission speed is set as a process value. The draft ratio of the low-temperature carbonization furnace to the filament bundle is set to be a process value of +0.3%.

After all the fibers are put on a silk collecting machine, a twisting machine is started, the motor frequency of the twisting machine is adjusted to be the technical twist, and the low-carbon drafting is restored to the technical value.

In this comparative example, the length of the racking operation was 14.3 hours, the wire was broken 6 times during the racking process, and the roller was wound 9 times.

And (3) technical effect analysis: compared with the first embodiment, the fourth embodiment is that the dividing grate is arranged after the dividing of the oxidation section is finished, after all the fibers are put on the frame, the twisting machine is started finally, the filaments are broken for 6 times in the process of putting on the frame, and the rollers are wound for 9 times, because the single-bundle fibers can be twisted to form an inclined spiral line, a compact structure which is not easy to damage transversely is formed, the strength unevenness is reduced, the filaments are tightly held together, the filaments are reduced, the fibers lose the advantages, adjacent fiber filaments are easy to hook after putting on the frame, a large number of broken filaments are wound together, and the putting on time is finally prolonged.

Those skilled in the art will readily appreciate that the advantageous features of the various aspects described above may be freely combined and stacked without conflict.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention. The foregoing is merely a preferred embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the technical principles of the present invention, and these modifications and variations should also be regarded as the scope of the invention.

Claims

1. The method for loading the twisted polyacrylonitrile fiber into the carbon fiber is characterized by comprising a starting step and a penetrating oxidation furnace step;

2. The method for loading the twisted polyacrylonitrile fiber into the carbon fiber according to claim 1, wherein the inlet of the No.1 oxidation furnace is provided with a yarn dividing device for auxiliary yarn dividing.

3. The method for feeding a twisted polyacrylonitrile fiber into a carbon fiber according to claim 2, wherein the outlet of the No. 1 oxidation furnace, the inlet of the No. 2-n oxidation furnace and the outlet are all provided with filament separating devices to keep filament bundles in a filament separated state;

preferably, the filament dividing device is a filament dividing grate.

4. The method of handling the carbon fiber during the production of the twisted polyacrylonitrile fiber according to claim 1, wherein in the step of starting the vehicle: the twist of the twisting equipment is set to be 10-50%; wherein x is the process twist.

5. The method for setting up a carbon fiber according to claim 1, wherein in the step of starting up, the initial draft ratio of the number 1 to n oxidizing furnaces to the filament bundles is set to-1% to 1%; when the filament bundle connector is out of the m-number oxidizing furnace, setting the drawing multiplying power of the m-number oxidizing furnace on the filament bundle as the process drawing multiplying power, wherein m is more than or equal to 1 and less than or equal to n;

6. The method for loading the twisted polyacrylonitrile fiber into the carbon fiber according to claim 5, wherein the heat preservation temperature of the number 1-n oxidation furnace is set to be 50-150 ℃ before the starting step; and/or

7. The method for loading operation in the process of producing carbon fibers from twisted polyacrylonitrile fibers according to claim 1, wherein in the starting step, the initial transmission speed of the transmission device is set to 50 to 200m/h; when the filament bundle connector is out of the No.1 oxidation furnace, the transmission speed is increased to 50% -75% of the process transmission speed value; after the tow is spliced out of the No. 4 oxidation oven, the transmission speed is increased to a process transmission speed value.

8. The method of handling the drawn carbon fiber during the production of the twisted polyacrylonitrile fiber according to claim 1, wherein the method of handling the drawn carbon fiber further comprises a carbonization furnace passing step; the carbonization furnace penetrating step comprises a low-temperature carbonization furnace penetrating step and a high-temperature carbonization furnace penetrating step;

9. The method according to claim 8, wherein the step of passing through a high temperature carbonization furnace further comprises a surface treatment step.

10. The method for handling the carbon fiber during the production of the carbon fiber by twisting the polyacrylonitrile fiber according to claim 9, wherein the method further comprises a preparation step before the starting step; wherein the preparing step includes: