Carbon fiber precursor broken filament online collecting device and broken filament amount evaluating method

Abstract

The invention provides an on-line carbon fiber precursor broken filament collecting device and a broken filament amount evaluating method, and belongs to the technical field of carbon fiber production equipment design, the on-line collecting device comprises a puffing treatment device and a fuzz collecting device, the puffing treatment device comprises a closed channel and an air injection ring located in the closed channel, and the fuzz collecting device comprises a fuzz collecting device. The carbon fiber precursor is positioned in the closed channel, runs along the length extension direction of the closed channel, and passes through the air injection ring; the air injection ring can inject pressure air flow so that the carbon fiber precursor bundle walking in the closed channel can be split, and broken filaments and / or broken ends in the carbon fiber precursor bundle can be at least partially transferred into the closed channel. The fuzz collecting device comprises a tow transmission roller and a fuzz scraping mechanism arranged corresponding to the tow transmission roller, the fuzz scraping mechanism comprises a scraper, and a knife edge of the scraper is tangent to the roller surface of the tow transmission roller so that broken filaments and / or broken ends adhering to the roller surface can be transferred to the scraper. According to the invention, the measurement of the fuzzing amount of the carbon fiber precursor bundle is more accurate.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon fiber production equipment design, and particularly relates to an on-line collecting device for carbon fiber precursor fluff and a method for evaluating the fluff amount. Background Art

[0002] Polyacrylonitrile-based carbon fiber has comprehensive properties such as high tensile strength, high tensile modulus, low density, corrosion resistance, and low thermal expansion, and has become an indispensable basic engineering material in the fields of aerospace, hydrogen storage cylinders, and wind power. Currently, more than 90% of commercial carbon fibers use polyacrylonitrile as the precursor material, and high-quality polyacrylonitrile precursor filaments are the basis for realizing high-performance carbon fibers.

[0003] In the production process of carbon fiber precursor filaments, due to factors such as unmatched drawing processes, filament bundle adhesion, and impurity influence, the fibers are extremely prone to defects and filament breakage, increasing the fluff amount of the final carbon fiber product, which has many adverse effects on the application of carbon fibers. Therefore, it is necessary to perform corresponding tests and measurements on the fluff amount of carbon fiber precursor filaments.

[0004] Currently, the methods for measuring the fluff amount in the industry include image extraction and friction collection. Among them, image extraction is to photograph the wound filament bundle or running fiber, and after image processing, characterize the fluff amount on the surface of the filament bobbin or the running fiber. This method cannot characterize the broken ends or fluff amount hidden in the filament bundle, has high requirements for equipment, and is difficult to locate the position where the fluff is generated; friction collection mainly drives the carbon fiber to move in the flocking device at a certain speed through a carbon fiber wear resistance detection system, and finally obtains the flocking amount of the carbon fiber by detecting the mass change of the flocking device. Compared with carbon fiber, the mechanical properties of carbon fiber precursor filaments are very different. The precursor filaments have a higher elongation at break and stronger toughness, and the fluff amount detected by making the precursor filaments contact and reciprocate with the wear-resistant material through a carbon fiber wear resistance detection system is not representative. Therefore, it is necessary to develop an on-line collecting device for carbon fiber precursor fluff and a method for evaluating the fluff amount. Summary of the Invention

[0005] Therefore, the present invention provides an on-line collecting device for carbon fiber precursor fluff and a method for evaluating the fluff amount, which can overcome the technical problem that when evaluating the fluff amount of carbon fiber precursor filaments by using the image extraction method in the related art, the amount of broken ends and / or fluff hidden in the filament bundle (i.e., the fluff amount) cannot be characterized, and the evaluation result is inaccurate.

[0006] To solve the above problems, the present invention provides an on-line collecting device for carbon fiber roving flyings, which includes an expansion treatment device and a flyings collecting device. The expansion treatment device and the flyings collecting device are arranged front and back along the wire running direction of the carbon fiber roving. Among them, the expansion treatment device includes a sealed passage and a jet ring located in the sealed passage. The carbon fiber roving is located in the sealed passage and runs along the length extension direction of the sealed passage, and the carbon fiber roving passes through the jet ring. The jet ring can eject a pressure air flow to fibrillate the carbon fiber roving bundle running in the sealed passage, so that at least part of the flyings and / or broken ends in the carbon fiber roving bundle are transferred into the sealed passage; the flyings collecting device includes a tow driving roller and a hair scraping mechanism arranged corresponding to the tow driving roller. The hair scraping mechanism includes a scraper, and the edge of the scraper is tangent to the roller surface of the tow driving roller to transfer the flyings and / or broken ends adhered to the roller surface onto the scraper.

[0007] In some embodiments, the expansion treatment device includes a plurality of the sealed passages, and the length extension directions of the sealed passages are arranged parallel to each other. Adjacent two sealed passages are separated by a partition; and / or, a set of wire guiding mechanisms are respectively arranged at the inner sides of the inlet and outlet of the sealed passage, and the wire running direction of the carbon fiber roving bundle is guided by the wire guiding mechanism. The jet ring is located between the two sets of wire guiding mechanisms; and / or, the inner ring wall surface of the jet ring has a plurality of air injection holes arranged around its central axis, and the diameter of each air injection hole is 1 mm to 3 mm; and / or, the hair scraping mechanism further includes a tool holder, and the scraper is detachably connected to the tool holder; and / or, the material of the scraper is woven carbon fiber or chopped carbon fiber; and / or, the on-line collecting device for carbon fiber roving flyings is arranged behind the drying densification device or the steam drawing device or the relaxation heat setting device in the carbon fiber roving production line.

[0008] In some embodiments, the wire guiding mechanism includes a flat wire guiding wheel and a width reducing wire guiding wheel. The width reducing wire guiding wheel is located between the flat wire guiding wheel and the jet ring, and each flat wire guiding wheel, width reducing wire guiding wheel and jet ring are arranged at intervals in sequence along the length extension direction of the sealed passage.

[0009] In some embodiments, within the same wire guiding mechanism, the carbon fiber roving bundle forms an up-and-down stagger on the wire guiding wheel surfaces respectively of the flat wire guiding wheel and the width reducing wire guiding wheel; and / or, the inner ring diameter of the jet ring is D, and the minimum distance between the jet ring and the width reducing wire guiding wheel is L, and D / (2L) is 5% to 20%.

[0010] In some embodiments, the width of the enclosed passageway is S, and S / D is 1.5 to 3.0; and / or, the width of the wire guiding surface of the planar wire guiding wheel is N, and N / D is 0.8 to 1.0; and / or, the width of the wire guiding surface of the wire reducing wheel is P, and P / D is 0.25 to 0.40.

[0011] In some embodiments, there are a plurality of the tow driving rollers and the hair scraping mechanisms. Each of the tow driving rollers corresponds to one of the hair scraping mechanisms respectively, and the tow driving rollers are arranged in a vertically staggered manner. Each of the hair scraping mechanisms is located on the opposite side of the tow wrapping surface of the corresponding tow driving roller.

[0012] In some embodiments, an inclined angle a is formed between the scraper and the vertical diameter line of the corresponding tow driving roller, a is 30° to 40°, and the inclined direction of the scraper is opposite to the rotation direction of the tow driving roller.

[0013] In some embodiments, the tow driving rollers are arranged alternately up and down in the horizontal direction. The length direction of the enclosed passageway is the vertical direction, and the tow wrapping surface of the tow driving roller closest to the outlet of the enclosed passageway is the lower surface of the tow driving roller. The number of the tow driving rollers is odd.

[0014] The present invention also provides a method for evaluating the amount of fluff and broken ends of carbon fiber precursor using the above-mentioned on-line collecting device for fluff and broken ends of carbon fiber precursor, including the following steps: S1: Control the continuous running of the carbon fiber precursor in the enclosed passageway corresponding to the puffing treatment device and the fluff collecting device. S2: Control the jet ring to eject a pressurized air flow so that the carbon fiber precursor is puffed into a round shuttle shape, and control the edge of the scraper of the fluff collecting device to be tangent to the roller surface of the tow driving roller. S3: Collect the fluff and / or broken ends in the enclosed passageway and on the scraper, and weigh to obtain the amount of fluff.

[0015] In some embodiments, after obtaining the amount of fluff, the following steps are further included: S4: Detect the diameter of the collected fluff and / or broken ends, and locate the generation position of the corresponding fluff and / or broken ends according to the diameter.

[0016] An on-line collecting device for fluff and broken ends of carbon fiber precursor and a method for evaluating the amount of fluff provided by the present invention have the following beneficial effects: During the process of the carbon fiber precursor tow running, the tow segment running inside the puffing treatment device is fibrillated by means of pressure air flow injection, that is, the puffing of the tow is realized. In this way, under the impact of the pressure air flow, the individual fiber filaments in the tow generate high-frequency vibrations, and the hairiness and broken ends hidden in the tow are at least partially transferred from the inside of the tow to the outside of the tow, such as on the outer surface of the tow and on the inner wall surface of the closed channel. Thus, the amount of hairiness inside the tow can be collected and evaluated. At the same time, since the fluff collection device is arranged on the downstream side of the puffing treatment device, during the running process of the fiber tow, the hairiness and broken ends on the outer surface of the tow can be adhered by the tow driving roller. At this time, a scraper can further collect this part of the hairiness and broken ends, so as to make the measurement of the hairiness amount of the carbon fiber precursor tow more accurate. Brief Description of the Drawings

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. The drawings in the following description are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained according to the provided drawings.

[0018] Figure 1 is a schematic diagram of the overall structure of the on-line carbon fiber precursor hairiness collection device in an embodiment of the present invention; Figure 2 is Figure 1 a partial enlarged view of part A in Figure 3 is Figure 1 the internal structure schematic diagram of the puffing treatment device in (the cover is omitted); Figure 4 is an optical microscope photograph of the carbon fiber precursor hairiness in Embodiment 1 of the present invention; Figure 5 is an optical microscope photograph of the carbon fiber precursor hairiness in Embodiment 2 of the present invention.

[0019] The reference numerals are explained as follows: 1. Puffing treatment device; 11. Closed channel; 12. Jet ring; 13. Partition board; 141. Plane wire guiding wheel; 142. Narrowing wire guiding wheel; 2. Fluff collection device; 21. Tow driving roller; 22. Hair scraping mechanism; 221. Scraper; 222. Knife holder; 3. Inlet driving roller. Detailed Embodiments

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way restricts the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the scope of protection of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0022] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" and the like can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientation of "above..." and "below...". The device can also be positioned in other different ways (rotated 90° or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0023] In addition, it should be noted that the use of words such as "first", "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above words have no special meanings. Therefore, it cannot be understood as a limitation on the scope of protection of the present invention.

[0024] See Figures 1 to 5As shown, according to an embodiment of the present invention, an on-line collecting device for carbon fiber precursor fuzz is provided, which includes an expansion treatment device 1 and a fuzz collecting device 2. The expansion treatment device 1 and the fuzz collecting device 2 are arranged front and back along the wire running direction of the carbon fiber precursor. Among them, the expansion treatment device 1 includes a closed passage 11 and a jet ring 12 located in the closed passage 11. The carbon fiber precursor is located in the closed passage 11 and runs along the length extension direction of the closed passage 11, and the carbon fiber precursor passes through the jet ring 12. The jet ring 12 can eject a pressure air flow (specifically provided by an air compressor) to open the carbon fiber precursor filament bundle running in the closed passage 11, so as to achieve the purpose of at least partially transferring the fuzz and / or broken ends in the carbon fiber precursor filament bundle into the closed passage 11; the fuzz collecting device 2 includes a filament bundle driving roller 21 and a fuzz scraping mechanism 22 corresponding to the filament bundle driving roller 21. The fuzz scraping mechanism 22 includes a scraper 221. The edge of the scraper 221 is tangent to the roller surface of the filament bundle driving roller 21 to transfer the fuzz and / or broken ends adhered to the roller surface onto the scraper 221. The aforementioned closed passage 11 specifically refers to that except for the inlet and outlet of the closed passage 11, during the operation of the expansion treatment device 1, the closed passage 11 is a relatively sealed container structure (generally a cuboid structure is sufficient). In order to prevent the fuzz and broken ends transferred into the closed passage 11 from escaping from the closed passage 11, the inlet and outlet should be filtered to ensure that the fuzz and broken ends are in the closed passage 11, thereby ensuring the accuracy of the fuzz amount measurement structure. The aforementioned fuzz specifically refers to the fuzz (and broken ends) that are not directly blown off by the expansion treatment device 1. However, after being treated by the expansion treatment device 1, the adhesion force of this part of the fuzz on the outer surface of the fiber filament bundle is weakened, and it will adhere to the surface of the filament bundle driving roller 21, that is, the fuzz that is everywhere on the roller surface, appears at random positions and at random times.

[0025] In this technical solution, during the process of the carbon fiber raw silk tow running, the bulking treatment device 1 uses a pressure air flow jet to open the tow segment running inside it, that is, to realize the bulking of the tow. In this way, under the impact of the pressure air flow, the individual fiber filaments in the tow generate high-frequency vibrations, and the hairiness and broken ends hidden in the tow are at least partially transferred from the inside of the tow to the outside of the tow, such as on the outer surface of the tow and the inner wall surface of the closed channel 11. Thus, the amount of hairiness inside the tow can be collected and evaluated. At the same time, since the hairiness collection device 2 is arranged on the downstream side of the bulking treatment device 1, during the process of the fiber tow running, the hairiness and broken ends on the outer surface of the tow can be adhered by the tow driving roller 21. At this time, a scraper 221 can further collect this part of the hairiness and broken ends, so as to make the measurement of the hairiness amount of the carbon fiber raw silk tow more accurate. It can be understood that in order to make the measurement structure of the hairiness amount accurate enough, the jet speed and jet pressure of the jet ring 12 can be increased in the bulking treatment device 1 on the premise of ensuring that the jetting will not cause the fiber tow to break and form hairiness, so as to ensure that as many as possible or even all of the broken ends and hairiness hidden inside the fiber tow due to manufacturing process or operation abnormalities are transferred to the outer surface of the tow and the inside of the closed channel 11.

[0026] In some embodiments, the bulking treatment device 1 includes a plurality of the closed channels 11, and the length extension directions of the respective closed channels 11 are arranged parallel to each other. Adjacent two of the closed channels 11 are separated by a partition 13. It can be understood that the bulking treatment device 1 further includes a closed outer shell (not labeled in the figure), and each of the partitions 13 is inside the closed outer shell. In this way, a plurality of the closed channels 11 arranged parallel to each other can be formed. In this technical solution, arranging a plurality of closed channels 11 arranged parallel to each other in the bulking treatment device 1 can independently perform bulking treatment on the fiber raw silk tows of different spinning positions.

[0027] In some embodiments, a set of wire guiding mechanisms (not labeled in the figure) are respectively arranged at the inner sides of the inlet and outlet of the closed channel 11. The running direction of the carbon fiber raw silk tow is guided by the wire guiding mechanisms. The jet ring 12 is located between the two sets of wire guiding mechanisms. In this way, under the jet action of the pressure air flow of the jet ring 12, each carbon fiber raw silk tow forms a round shuttle shape with smaller ends and larger middle, so as to increase the gap between the tows, make the broken ends or hairiness easier to be exposed and further be blown into the closed channel 11, and increase the probability of adhesion of the broken ends or hairiness to the tow driving roller 21; and / or, the inner ring wall surface of the jet ring 12 has a plurality of jet holes (not shown and not labeled in the figure) arranged around its central axis. The diameter of each jet hole is 1 mm to 3 mm. If the diameter of the jet hole is too small, the air flow impact is small and it is difficult to blow the tow into a round shuttle shape. If the diameter of the jet hole is too large, it is not conducive to the control of the bulking ratio and it is easy to blow it too large and make the tow hairy.

[0028] The hair scraping mechanism 22 further includes a tool holder 222, and the scraper 221 is detachably connected to the tool holder 222. Since the scraper 221 is detachably connected to the tool holder 222, it can be replaced in a timely and convenient manner after the scraper 221 is worn out after long-term use, improving the overall service life of the hair scraping mechanism 22.

[0029] In a specific embodiment, the material of the scraper 221 is woven carbon fiber or chopped carbon fiber, which has the advantages of high strength and low density.

[0030] The carbon fiber raw silk hair wire online collection device is arranged behind the drying densification device or the steam drawing device or the relaxation heat setting device in the carbon fiber raw silk production line to ensure sufficient fiber opening and puffing of the carbon fiber raw silk bundle, and further ensure reliable and accurate evaluation of the amount of raised hair. Additionally, it is worth emphasizing that setting the prior collection device of the present invention after the foregoing processes can collect the hair wires in the entire process range from spinning to wire collection, and evaluate the amount of hair wires carried in the raw silk more accurately and comprehensively.

[0031] Specifically refer to Figure 3 As shown, in some embodiments, the wire guiding mechanism includes a flat wire guiding wheel 141 and a width reducing wire guiding wheel 142, wherein the width reducing wire guiding wheel 142 is located between the flat wire guiding wheel 141 and the air jet ring 12, and each of the flat wire guiding wheel 141, the width reducing wire guiding wheel 142 and the air jet ring 12 are sequentially arranged at intervals along the length extension direction of the closed channel 11.

[0032] In this technical solution, the flat wire guiding wheel 141 guides the running path of the carbon fiber raw silk bundle entering and exiting the closed channel 11, preventing the wire bundle from deviating too much in the closed channel 11 and contacting the wall surface of the closed channel 11, causing wear and exacerbating hair formation of the wire bundle. On the other hand, setting the width reducing wire guiding wheel 142 between the flat wire guiding wheel 141 and the air jet ring 12 has the following specific advantages: (1) Preventing wire bundle from slipping out: The width reducing guide wheel can limit the wire bundle within a certain range after passing through the puffing treatment module, avoiding some wire bundles from slipping out from the upper and lower small guide wheels due to being blown away, thereby preventing problems such as wire bundle snagging and breaking, and ensuring the continuity and stability of the production process; (2) Optimizing the blowing effect: After width reduction, the wire bundle is more concentrated, and the compressed air blown out by the puffing treatment module can act on the wire bundle more evenly and effectively, causing the wire bundle to spread out from the center into a spindle shape, ensuring that the broken ends in the wire bundle can be better blown off, and at the same time maintaining the neat arrangement of single filaments, improving the air treatment effect; (3) If only normal-width guide wheels are used, the tow is likely to slip out of the guide wheels after being blown open; and for a tow with a normal width, it is difficult to obtain a uniform and appropriate blowing force across the entire width of the tow, and there may be a situation where the force at the edges is too large or too small, resulting in the tow being easily blown disorderly or split into several strands. (4) After passing through the width-reducing wire guide wheels, the position of the tow during operation is more accurate, which is beneficial for the positioning of the subsequent steam drawing furnace or the wire winding machine, avoiding the tow running off track during operation and preventing the tows from interfering with each other.

[0033] In some embodiments, within the same wire guiding mechanism, the carbon fiber raw silk tow forms an up-and-down stagger on the wire guiding surfaces respectively possessed by the flat wire guide wheel 141 and the width-reducing wire guide wheel 142, so as to utilize the wrap angles of the tow with the different wheel surfaces of the flat wire guide wheel 141 and the width-reducing wire guide wheel 142, thereby improving the wire guiding stability of the tow. The aforementioned up-and-down stagger, with Figure 3 the shown orientation as a reference, that is, the front-and-back stagger in the orientation of the paper surface.

[0034] Refer to Figure 3 As shown, the inner diameter of the jet ring 12 is D, the minimum distance between the jet ring 12 and the width-reducing wire guide wheel 142 is L, and D / (2L) is 5% - 20%. If D / (2L) is too small, it is difficult to blow the tow into a round shuttle shape and it is not easy to blow out the fluff in it. On the contrary, if D / (2L) is too large, the tow is likely to be fluffed or the tow is blown open too much and is larger than the space of the puffing treatment device 1, resulting in the tow slipping out of the wire guide wheel in the tow after the tow is blown open in a shuttle shape and exceeds the space of the puffing treatment device 1.

[0035] The width of the closed channel 11 is S, and S / D is 1.5 - 3.0. If S / D is too small, it is not conducive to putting the tow into the puffing treatment device 1 during operation and is not conducive to collecting the fluff in the closed channel 11. While if S / D is too large, it wastes space and is not conducive to improving production efficiency. In a specific embodiment, the width of the wire guiding surface of the flat wire guide wheel 141 is N, and N / D is 0.8 - 1.0; and / or, the width of the wire guiding surface of the width-reducing wire guide wheel 142 is P, and P / D is 0.25 - 0.40.

[0036] In some embodiments, there are multiple tow driving rollers 21 and multiple hair scraping mechanisms 22. Each of the tow driving rollers 21 and each of the hair scraping mechanisms 22 correspond to each other one by one, and each of the tow driving rollers 21 forms an up-and-down stagger. Each of the hair scraping mechanisms 22 is located on the opposite side of the wire wrapping surface of the corresponding tow driving roller 21. Using multiple groups of tow driving rollers 21 and hair scraping mechanisms 22 can fully adhere to the fluff on the outer surface of the carbon fiber raw silk tow that forms a wrap angle with it, thereby ensuring the full collection of the fluff and further ensuring the accuracy of the fluff amount evaluation result.

[0037] In some embodiments, an inclined included angle α is formed between the doctor blade 221 and the vertical diameter line of the corresponding tow driving roller 21, where α is 30° to 40°, and the inclined direction of the doctor blade 221 is opposite to the rotation direction of the tow driving roller 21, so as to ensure that the doctor blade 221 can fully collect the fly filaments adhering to the roller surface of the tow driving roller 21. In this technical solution, the inclined angle of the doctor blade 221 is optimized and limited, preventing the excessive angle from reducing the supporting force of the doctor blade 221 and decreasing the scraping effect on broken filaments, and also preventing the angle from being too small, which increases the space occupation and blade loss.

[0038] In some embodiments, the tow driving rollers 21 are alternately arranged up and down in the horizontal direction, the length direction of the closed passage 11 is the vertical direction, and the tow wrapping surface of the tow driving roller 21 closest to the outlet of the closed passage 11 is the lower surface of the tow driving roller 21. The number of the tow driving rollers 21 is odd, so as to ensure that the height of the tow led out by the on-line fly filament collecting device for carbon fiber precursor of the present invention is relatively low, which is convenient for subsequent operations on the tow.

[0039] According to an embodiment of the present invention, there is also provided a method for evaluating the amount of fly filaments of carbon fiber precursor using the above on-line fly filament collecting device for carbon fiber precursor, including the following steps: S1: Control the carbon fiber precursor to continuously travel in the closed passage 11 corresponding to the puffing treatment device 1 and the fly filament collecting device 2; S2: Control the jet ring 12 to eject a pressure air flow so that the carbon fiber precursor puffs up into a round shuttle shape, and control the cutting edge of the doctor blade 221 of the fly filament collecting device 2 to be tangent to the roller surface of the tow driving roller 21; S3: Collect the fly filaments and / or broken ends in the closed passage 11 and on the doctor blade 221, and weigh to obtain the amount of fly filaments. Specifically, the above-mentioned closed passages 11 and the doctor blade 221 can be manually swept and collected, and of course, other collection methods can also be used, such as negative pressure (vacuum) adsorption.

[0040] In this technical solution, during the process of the carbon fiber raw silk tow running, the bulking treatment device 1 sprays a pressure air flow (compressed air) on the tow segment running inside it to open the fibers of this segment of the tow, that is, to achieve the bulking of the tow. In this way, under the impact of the pressure air flow, the individual fiber filaments in the tow generate high-frequency vibrations, and the hairiness and broken ends hidden in the tow are at least partially transferred from inside the tow to the outside of the tow, such as on the outer surface of the tow and the inner wall surface of the closed channel 11. Thus, the amount of hairiness inside the tow can be collected and evaluated. At the same time, since the hairiness collection device 2 is arranged on the downstream side of the bulking treatment device 1, during the process of the fiber tow running, the hairiness and broken ends on the outer surface of the tow can be adhered by the tow driving roller 21. At this time, a scraper 221 can further collect this part of the hairiness and broken ends, so as to make the measurement of the hairiness amount of the carbon fiber raw silk tow more accurate.

[0041] In some embodiments, after obtaining the amount of hairiness, the following steps are further included: S4: Detect and obtain the diameter of the collected hairiness and / or broken ends (which can be detected by an optical microscope), and locate the generation position of the corresponding hairiness and / or broken ends according to the diameter. Taking the case where the carbon fiber raw silk is manufactured by a wet spinning process or a dry-jet wet spinning process as an example, the diameter range of the hairiness filaments in the carbon fiber raw silk tow formed by this process generally ranges from 9 to 150 μm, and there are often significant differences in the diameters of the hairiness filaments formed in different production stages of different processes. Thus, by detecting the diameter of the collected hairiness and / or broken ends, it can be further deduced which section of the corresponding production process the hairiness of this diameter is generated in (that is, locate the generation position of the hairiness), and then evaluate the matching degree of the spinning process or the stability of the operating state, providing strong support for improving the process application performance of the carbon fiber raw silk and carbon fiber.

[0042] In a specific embodiment, the aforementioned bulking treatment device 1 and hairiness collection device 2 are assembled on the same mounting bracket to ensure the reliable and accurate relative mounting position between the two.

[0043] The following further elaborates on the device and method of the invention in combination with two specific embodiments.

[0044] Example 1 An on-line hairiness collection device for carbon fiber raw silk includes a bulking treatment device 1 and a hairiness collection device 2.

[0045] The puffing treatment device 1 is located between the upper and lower driving rollers, and includes a box body (i.e., the aforementioned airtight outer shell, the same below), a channel partition (i.e., the aforementioned partition 13, the same below), a wire guiding device (i.e., the aforementioned wire guiding mechanism, the same below), and a jet ring. A number of channel partitions are arranged in the box body to divide the box body into a number of channels (i.e., the aforementioned airtight channels 11, the same below). The position of each channel corresponds to the running spinning position of the carbon fiber roving. A wire guiding mechanism (two groups front and back) and a group of jet rings are arranged in the channel.

[0046] The jet ring is circular, with an inner diameter of D (15 mm); the distance between the wire guiding mechanism and the jet ring is L (60 mm); D / (2L) is 12.5%.

[0047] The width of the channel is S (45 mm), and S / D is 3.0.

[0048] A number of compressed air spray holes (i.e., the aforementioned spray holes, the same below) are arranged on the inner wall of the jet ring. The diameter of the spray holes is 2 mm, and the number is 6.

[0049] The wire guiding mechanism includes a flat wire guiding wheel and a concave wire guiding wheel (i.e., the aforementioned amplitude-reducing wire guiding wheel mentioned above). The width of the flat wire guiding wheel is N (12 mm), and N / D is 0.8; the width of the concave wire guiding wheel after amplitude reduction is P (5 mm), and P / D is 0.33.

[0050] The fluff collecting device 2 is arranged in the opposite direction of the tangent plane of the driving roller and the carbon fiber roving, and includes a scraping blade (i.e., the aforementioned scraper 221, the same below) and a blade support (i.e., the aforementioned tool holder 222, the same below). The number of the fluff collecting devices 2 is 5 groups.

[0051] The central axis of the blade support is in the vertical direction and coincides with the center point of the corresponding driving roller (i.e., the aforementioned tow driving roller 21, the same below).

[0052] The angle between the scraping blade and the central axis of the blade support is 35°.

[0053] The material of the scraping blade is woven carbon fiber.

[0054] After setting the carbon fiber roving fluff online collecting device behind the drying and densifying device, the fluff amount of the carbon fiber roving prepared by the dry-jet wet spinning process is evaluated, including the following steps: S1: Puffing treatment step. The carbon fiber roving with a specification of 12K enters the corresponding spinning position channel of the puffing treatment device 1 through the upper driving roller. After entering the channel, it passes through the wire guiding mechanism and passes through the center of the jet ring. Under the action of compressed air, the fluff carried by the fiber is blown off in a round shuttle shape. The puffing ratio D / (2L) of the roving is 12.5%, and the compressed air pressure is 0.5 bar; S2: Fluffy hair collection step. The unblown fluffy filaments on the carbon fiber raw yarn after puffing treatment adhere to the surface of the driving roller and are scraped and collected by the scraping blade of the fluffy hair collection device 2. S3: Collection and weighing step. When 12 hours have passed, collect the fluffy filaments collected in the channel and on the scraping blade; the weighing value is 0.72 g, and the amount of fluffy filaments M is 0.72 g.

[0055] Observe the collected fluffy filaments under an optical microscope. The fiber diameter of the fluffy filaments is about 100 μm. Based on the evolution law of the fiber diameter during the preparation of carbon fiber raw yarn, it is inferred that the fluffy filaments come from the breakage of the spinning dope stream in the air section, and the reason is that there are abnormal holes in the spinneret. After replacing the spinneret, evaluate the amount of fluffy filaments again. When 12 hours have passed, collect the fluffy filaments collected in the channel and on the scraping blade; the weighing value is 0.12 g, and the amount of fluffy filaments M is 0.12 g, and the operating state is stable.

[0056] Example 2 The structure of the on-line collection device for fluffy filaments of carbon fiber raw yarn is the same as that of Example 1.

[0057] After setting the on-line collection device for fluffy filaments of carbon fiber raw yarn behind the steam drawing furnace, evaluate the amount of fluffy filaments of carbon fiber raw yarn prepared by the dry-jet wet-spinning process, including the following steps: S1: Puffing treatment step. Carbon fiber raw yarn with a specification of 12K enters the corresponding spinning position channel of the puffing treatment device 1 through the upper driving roller. After entering the channel, it passes through the wire guiding mechanism and passes through the center of the air jet ring, and the fluffy filaments on the fiber are blown off in a round shuttle shape under the action of compressed air. The puffing ratio D / (2L) of the raw yarn is 12.5%, and the compressed air pressure is 0.6 bar. S2: Fluffy hair collection step. The unblown fluffy filaments on the carbon fiber raw yarn after puffing treatment adhere to the surface of the driving roller and are scraped and collected by the scraping blade of the fluffy hair collection device 2. S3: Collection and weighing step. When 12 hours have passed, collect the fluffy filaments collected in the channel and on the scraping blade; the weighing value is 0.34 g, and the amount of fluffy filaments M is 0.34 g.

[0058] Observe the collected fluffy filaments under an optical microscope. The fiber diameter of the fluffy filaments is about 10 μm. Based on the evolution law of the fiber diameter during the preparation of carbon fiber raw yarn, it is inferred that the fluffy filaments come from the fiber breakage during the steam drawing process, and the reason is that the steam drawing pressure is too low. After adjusting the steam drawing pressure, evaluate the amount of fluffy filaments again. When 12 hours have passed, collect the fluffy filaments collected in the channel and on the scraping blade; the weighing value is 0.08 g, and the amount of fluffy filaments M is 0.08 g, and the operating state is stable.

[0059] Those skilled in the art can easily understand that, on the premise of no conflict, the advantageous technical features of the above-mentioned various methods can be freely combined and superimposed.

[0060] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An on-line collecting device for carbon fiber precursor fuzz, characterized in that, It includes an expansion treatment device (1) and a fluff collection device (2). The expansion treatment device (1) and the fluff collection device (2) are arranged in sequence along the wire feeding direction of the carbon fiber roving. Among them, the expansion treatment device (1) includes a closed channel (11) and a jet ring (12) located inside the closed channel (11). The carbon fiber roving is located inside the closed channel (11) and runs along the length extension direction of the closed channel (11), and the carbon fiber roving passes through the jet ring (12). The jet ring (12) can eject a pressure air flow so that the carbon fiber roving bundle traveling in the closed channel (11) is fibrillated, and at least part of the fluff and / or broken ends in the carbon fiber roving bundle are transferred into the closed channel (11); the fluff collection device (2) includes a tow drive roller (21) and a fluff scraping mechanism (22) arranged corresponding to the tow drive roller (21). The fluff scraping mechanism (22) includes a scraper (221), and the cutting edge of the scraper (221) is tangent to the roller surface of the tow drive roller (21) to transfer the fluff and / or broken ends adhered to the roller surface onto the scraper (221).

2. The on-line collecting device for carbon fiber precursor flyings according to claim 1, wherein The expansion treatment device (1) includes a plurality of the closed channels (11), and the length extension directions of the closed channels (11) are arranged parallel to each other. Adjacent two closed channels (11) are separated by a partition plate (13); and / or, a set of wire guiding mechanisms are respectively arranged at the inner sides of the inlet and outlet of the closed channel (11). The wire feeding direction of the carbon fiber roving bundle is guided by the wire guiding mechanisms, and the jet ring (12) is located between the two sets of wire guiding mechanisms; and / or, the inner ring wall surface of the jet ring (12) has a plurality of air injection holes arranged around its central axis, and the diameter of each air injection hole is 1 mm to 3 mm; and / or, the fluff scraping mechanism (22) further includes a tool holder (222), and the scraper (221) is detachably connected to the tool holder (222); and / or, the material of the scraper (221) is woven carbon fiber or chopped carbon fiber; and / or, the online fluff collection device for the carbon fiber roving is arranged behind the drying densification device or the steam drawing device or the relaxation heat setting device in the carbon fiber roving production line.

3. The on-line collecting device for carbon fiber precursor fuzz according to claim 2, characterized in that, The wire guiding mechanism includes a flat wire guiding wheel (141) and a width reducing wire guiding wheel (142). Among them, the width reducing wire guiding wheel (142) is located between the flat wire guiding wheel (141) and the jet ring (12), and each flat wire guiding wheel (141), width reducing wire guiding wheel (142) and jet ring (12) are arranged at intervals in sequence along the length extension direction of the closed channel (11).

4. The on-line collecting device for carbon fiber precursor flyings according to claim 3, characterized in that, Within the same wire guiding mechanism, the carbon fiber roving bundles are staggered up and down on the wire guiding surfaces respectively provided on the flat wire guiding wheel (141) and the width-reducing wire guiding wheel (142); and / or, the inner ring diameter of the air jet ring (12) is D, the minimum distance between the air jet ring (12) and the width-reducing wire guiding wheel (142) is L, and D / (2L) is 5% to 20%.

5. The on-line collecting device for carbon fiber precursor fuzz as claimed in claim 4, wherein, The width of the closed channel (11) is S, and S / D is 1.5 to 3.0; and / or, the width of the wire guiding surface of the flat wire guiding wheel (141) is N, and N / D is 0.8 to 1.0; and / or, the width of the wire guiding surface of the width-reducing wire guiding wheel (142) is P, and P / D is 0.25 to 0.

40.

6. The online collecting device for carbon fiber precursor flyings according to claim 2, wherein, There are a plurality of the roving transmission rollers (21) and the hair scraping mechanisms (22). Each of the roving transmission rollers (21) corresponds to one of the hair scraping mechanisms (22) respectively, and the roving transmission rollers (21) are staggered up and down. Each of the hair scraping mechanisms (22) is located on the opposite side of the wire bundle wrapping surface of the corresponding roving transmission roller (21).

7. The on-line collecting device for carbon fiber pre-twisted yarn flyings according to claim 6, wherein, An inclined angle a is formed between the blade (221) and the vertical diameter line of the corresponding roving transmission roller (21), a is 30° to 40°, and the inclined direction of the blade (221) is opposite to the rotation direction of the roving transmission roller (21).

8. The online collecting device for carbon fiber precursor flyings according to claim 6, characterized in that, The roving transmission rollers (21) are arranged alternately up and down in the horizontal direction. The length direction of the closed channel (11) is the vertical direction. The wire bundle wrapping surface of the roving transmission roller (21) closest to the outlet of the closed channel (11) is the lower surface of the roving transmission roller (21), and the number of the roving transmission rollers (21) is odd.

9. A method for evaluating the amount of fluff in carbon fiber precursor filaments using the on-line fluff collection device for carbon fiber precursor filaments described in any one of claims 1 to 8, characterized in that, It includes the following steps: S1: Control the continuous running of the carbon fiber roving in the corresponding closed channel (11) of the puffing treatment device (1) and the fluff collecting device (2); S2: Control the air jet ring (12) to eject pressurized air flow so that the carbon fiber roving puffs up to form a round shuttle shape, and control the edge of the blade (221) of the fluff collecting device (2) to be tangent to the roller surface of the roving transmission roller (21); S3: Collect the hair filaments and / or broken ends in the closed channel (11) and on the blade (221), and weigh to obtain the amount of hair filaments.

10. The method for evaluating the amount of fiber fly in carbon fiber precursor according to claim 9, characterized in that, After obtaining the amount of hair filaments, the following steps are further included: S4: Detect the diameter of the collected hair filaments and / or broken ends, and locate the generation positions of the corresponding hair filaments and / or broken ends according to the diameter.

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