Carbon fiber precursor thread breakage on-line collection device and thread breakage amount evaluation method

Abstract

The present application provides a kind of carbon fiber precursor thread fuzz online collection device and fuzz amount evaluation method, belong to carbon fiber production equipment design technical field, online collection device includes bulking treatment device and fuzz collection device, bulking treatment device includes closed duct and the air jet ring in it, carbon fiber precursor thread is in closed duct and along the length extension direction of closed duct operation, and carbon fiber precursor thread passes through in air jet ring, air jet ring can spray pressure airflow to make the carbon fiber precursor thread bundle in closed duct running open fiber realize that at least part of fuzz and / or broken head in carbon fiber precursor thread bundle is transferred to closed duct;Fuzz collection device includes bundle transmission roller and the scraping mechanism that is correspondingly arranged with bundle transmission roller, scraping mechanism includes scraper, the cutting edge of scraper is tangent with the roll surface of bundle transmission roller to transfer the fuzz and / or broken head adhered on roll surface on scraper.The present application makes the metering of the fuzz amount of carbon fiber precursor thread bundle more accurate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of carbon fiber production equipment design, and particularly relates to a carbon fiber precursor filament fluff online collection device and a fluff amount evaluation method. BACKGROUND

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

[0003] In the production process of carbon fiber precursors, due to factors such as mismatched drafting process, filament adhesion, and impurity influence, the fibers are prone to defects and breakage, increasing the fluff amount of the final carbon fiber product, and causing many adverse effects on the application of carbon fibers. Therefore, it is necessary to test and measure the fluff amount of the carbon fiber precursors.

[0004] At present, the methods for measuring the fluff amount in the industry include image extraction and friction collection. Among them, image extraction is to characterize the fluff amount of the filament surface or running fiber by taking pictures of the wound filament or running fiber and image processing. 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 at a certain speed in the fluff device through the carbon fiber wear resistance detection system, and finally obtains the fluff amount of the carbon fiber by detecting the mass change of the fluff device. Compared with carbon fibers, there are great differences in the mechanical properties of carbon fiber precursors. The elongation at break of the precursors is higher, and the toughness is stronger. The fluff amount detected by the carbon fiber wear resistance detection system by contacting and reciprocating the precursors with the wear-resistant material is not representative. Therefore, it is necessary to develop a fluff online collection device for carbon fiber precursors and a fluff amount evaluation method. SUMMARY

[0005] Therefore, the present application provides a carbon fiber precursor filament fluff online collection device and a fluff amount evaluation method, which can overcome the technical problem that the fluff amount evaluation method using image extraction cannot characterize the amount of broken ends and / or fluff (i.e., the fluff amount) hidden in the filament bundle when evaluating the fluff amount of carbon fiber precursors, and the evaluation result is inaccurate.

[0006] To solve the above problems, the present application provides a kind of carbon fiber precursor filament on-line collection device, including bulking treatment device and hair collecting device, the bulking treatment device and the hair collecting device are arranged before and after along the carbon fiber precursor filament direction of wire, wherein, the bulking treatment device includes closed channel and jet ring in the closed channel, the carbon fiber precursor filament is in the closed channel and along the length direction of the closed channel runs, and the carbon fiber precursor filament passes through the jet ring, the jet ring can spray pressure airflow to make the carbon fiber precursor filament bundle in the closed channel run open to achieve the hair and / or broken head in the carbon fiber precursor filament bundle at least partially transfer to the closed channel;The hair collecting device includes bundle transmission roller and corresponding arranged scraping mechanism with the bundle transmission roller, the scraping mechanism includes scraper, the knife edge of the scraper is tangent with the roll surface of the bundle transmission roller to transfer the hair and / or broken head adhered to the roll surface on the scraper.

[0007] In some embodiments, the bulking treatment device includes a plurality of closed channels, and the length extension direction of each closed channel is arranged parallel to each other, and the adjacent two closed channels are separated by a partition plate;And / or, a group of guide mechanisms is arranged at the inner side of the inlet and outlet of the closed channel respectively, the wire direction of the carbon fiber precursor filament bundle is guided by the guide mechanism, and the jet ring is between the two groups of guide mechanisms;And / or, the inner ring wall surface of the jet ring has a plurality of jet holes arranged around the central axis, and the diameter of each jet hole is 1mm-3mm;And / or, the scraping mechanism further includes a knife seat, and the scraper is detachably connected to the knife seat;And / or, the material of the scraper is woven carbon fiber or chopped carbon fiber;And / or, the carbon fiber precursor filament on-line collection device is arranged after the drying densification device or after the steam stretching device or after the relaxation heat setting device in the carbon fiber precursor filament production line.

[0008] In some embodiments, the guide mechanism includes a planar guide wheel and a necking guide wheel, wherein the necking guide wheel is between the planar guide wheel and the jet ring, and each planar guide wheel, necking guide wheel and jet ring are sequentially and spacedly arranged along the length extension direction of the closed channel.

[0009] In some embodiments, in the same guide mechanism, the carbon fiber precursor filament bundle forms up-and-down stagger on the guide wheel surface of the planar guide wheel and the necking guide wheel respectively;And / or, the inner ring diameter of the jet ring is D, the minimum distance between the jet ring and the necking guide wheel is L, and D / (2L) is 5%-20%.

[0010] In some embodiments, the closed duct has a width S, S / D is 1.5-3.0; and / or, the plane godet has a godet face width N, N / D is 0.8-1.0; and / or, the converging godet has a godet face width P, P / D is 0.25-0.40.

[0011] In some embodiments, the plurality of bundle driving rollers and the plurality of scraping mechanisms are one-to-one corresponding respectively, and each of the bundle driving rollers is staggered vertically, and each of the scraping mechanisms is located at the opposite side of the bundle covering surface of the corresponding bundle driving roller.

[0012] In some embodiments, an included angle a is formed between the scraping knife and the vertical diameter line of the corresponding bundle driving roller, a is 30-40°, and the inclination direction of the scraping knife is opposite to the rotation direction of the bundle driving roller.

[0013] In some embodiments, each of the bundle driving rollers is alternatively arranged in the horizontal direction, the length direction of the closed duct is vertical, the bundle covering surface of the bundle driving roller closest to the outlet of the closed duct is the lower surface of the bundle driving roller, and the number of the bundle driving rollers is odd.

[0014] The application also provides a carbon fiber precursor fiber fuzz amount evaluation method using the above-described carbon fiber precursor fiber fuzz online collection device, comprising the following steps:

[0015] S1: controlling the carbon fiber precursor to continuously run in the corresponding closed duct of the puffing treatment device and the fuzz collecting device;

[0016] S2: controlling the jet ring to spray pressure airflow so that the carbon fiber precursor is puffed into a round shuttle shape, and controlling the knife edge of the scraping knife of the fuzz collecting device to be tangent to the roller surface of the bundle driving roller;

[0017] S3: collecting the fuzz and / or broken ends in the closed duct and on the scraping knife, and weighing to obtain the fuzz amount.

[0018] In some embodiments, after obtaining the fuzz amount, the following step is further included:

[0019] S4: detecting the diameter of the collected fuzz and / or broken ends, and locating the position of the corresponding fuzz and / or broken ends according to the diameter.

[0020] The carbon fiber precursor fiber fuzz online collection device and the fuzz amount evaluation method provided by the application have the following beneficial effects:

[0021] In the carbon fiber precursor filament tow wire drawing process, the filament segment running in the device is subjected to pressure airflow injection to realize the opening of the filament segment, that is, the filament expansion. Under the impact of the pressure airflow, the fibers in the filament produce high-frequency vibration, and the loose fibers and broken ends in the filament are at least partially transferred to the outside of the filament, such as the outer surface of the filament and the inner wall surface of the closed channel, so that the amount of loose fibers inside the filament can be collected and measured. Since the loose fiber collecting device is arranged on the downstream side of the expansion treatment device, the loose fibers and broken ends on the outer surface of the filament can be adhered by the filament transmission roller during the fiber filament wire drawing process. At this time, the loose fibers and broken ends can be further collected by the scraper, so that the measurement of the amount of loose fibers of the carbon fiber precursor filament is more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. The drawings in the following description are only exemplary, and those skilled in the art can also obtain other implementation drawings according to the provided drawings without creative labor.

[0023] Figure 1 is a schematic diagram of the overall structure of the carbon fiber precursor loose fiber on-line collecting device in the embodiment of the present application;

[0024] Figure 2 is Figure 1 is a partial enlarged view of A in

[0025] Figure 3 is Figure 1 is a schematic diagram of the internal structure of the expansion treatment device in

[0026] Figure 4 is an optical microscope photo of the carbon fiber precursor loose fiber in the embodiment 1 of the present application;

[0027] Figure 5 is an optical microscope photo of the carbon fiber precursor loose fiber in the embodiment 2 of the present application.

[0028] The reference signs are explained as follows:

[0029] 1, expansion treatment device; 11, closed channel; 12, air injection ring; 13, partition; 141, planar godet; 142, amplitude-reducing godet; 2, loose fiber collecting device; 21, filament transmission roller; 22, loose fiber scraping mechanism; 221, scraper; 222, knife holder; 3, inlet transmission roller. DETAILED DESCRIPTION

[0030] Clearly, the embodiments described are only a part of all the embodiments of the present application, rather than all the embodiments. The following description of at least one example embodiment is merely illustrative in nature and does not limit the present application or its applications or uses in any way. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0031] In the description of the present application, it should be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship are generally based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, without the opposite description, these orientation words do not indicate and imply that the indicated device or element 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 application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0032] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Therefore, the example term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0033] In addition, it should be noted that the use of "first", "second" and the like to define parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, therefore it cannot be understood as a limitation on the scope of protection of the present application.

[0034] Referring to Figures 1 to 5As shown, according to the embodiment of the present application, a kind of carbon fiber precursor filament online collection device is provided, including puffing treatment device 1 and generic hair collection device 2, puffing treatment device 1 and the generic hair collection device 2 are set up before and after along the carbon fiber precursor filament's wire direction, wherein, puffing treatment device 1 includes closed channel 11 and jet ring 12 in closed channel 11, the carbon fiber precursor filament is in closed channel 11 and along the length direction of closed channel 11 runs, and the carbon fiber precursor filament passes through in jet ring 12, jet ring 12 can spray pressure airflow (specifically can be provided by air compressor) to make the carbon fiber precursor filament bundle that runs in closed channel 11 open fiber to achieve the purpose that the hair and / or broken head in the carbon fiber precursor filament bundle at least partially shifts to closed channel 11;Generic hair collection device 2 includes bundle transmission roller 21 and the scraping mechanism 22 that is correspondingly set with bundle transmission roller 21, scraping mechanism 22 includes scraper 221, the cutting edge of scraper 221 is tangent to the roll surface of bundle transmission roller 21 to transfer the hair and / or broken head adhered to the roll surface on scraper 221.The foregoing closed channel 11 specifically refers to, except the entrance and exit of closed channel 11, during the use of puffing treatment device 1, closed channel 11 is a relatively sealed container structure (generally as cuboid structure can), and in order to prevent the hair and broken head that shifts to closed channel 11 from escaping from closed channel 11, should be filtered to its entrance and exit, ensure that hair and broken head are in the closed channel 11, to ensure the accuracy of the metering structure of hair amount.The foregoing generic hair specifically refers to, the hair (and broken head) that is not directly blown down by puffing treatment device 1, but after the treatment of puffing treatment device 1, the adhesion of this part of hair on the surface of fiber bundle is weakened, after subsequent bundle transmission roller 21, it will be adhered to the surface of bundle transmission roller 21, i.e. the hair on the roll surface everywhere, randomly position appears, randomly time appears.

[0035] In the technical scheme, the carbon fiber precursor filament bundle is subjected to pressure airflow injection in the bulking treatment device 1 to realize fiber opening and bulking of the filament bundle, so that the fibers in the filament bundle vibrate at high frequency, and the broken ends and the loose fibers in the filament bundle are at least partially transferred to the outside of the filament bundle, such as the outer surface of the filament bundle and the inner wall of the closed channel 11, so that the amount of loose fibers in the filament bundle can be collected and measured. Since the loose fiber collecting device 2 is arranged on the downstream side of the bulking treatment device 1, the loose fibers and the broken ends on the outer surface of the filament bundle can be adhered by the filament bundle transmission roller 21 during the filament process of the fiber bundle. At this time, the loose fibers and the broken ends can be further collected by the scraper 221, so that the measurement of the amount of loose fibers of the carbon fiber precursor filament bundle is more accurate. It can be understood that, in order to make the measurement structure of the amount of loose fibers accurate enough, the jet speed and the jet pressure of the jet ring 12 in the bulking treatment device 1 can be increased under the premise that the jet does not cause the filament bundle to break and the loose fibers, so as to ensure that the broken ends and the loose fibers hidden in the filament bundle due to manufacturing process or abnormal operation are transferred to the outer surface of the filament bundle and the inner wall of the closed channel 11 as much as possible or even all.

[0036] In some embodiments, the bulking treatment device 1 includes a plurality of closed channels 11, and the length extension directions of the closed channels 11 are arranged in parallel with each other, and two adjacent closed channels 11 are separated by a partition plate 13. It can be understood that the bulking treatment device 1 further includes a closed shell (not shown in the figure), and the partition plates 13 are in the closed shell, so that a plurality of closed channels 11 arranged in parallel with each other are formed. In the technical scheme, the plurality of closed channels 11 arranged in parallel with each other in the bulking treatment device 1 can be used to independently bulking treat the fiber precursor filaments of different spinning positions.

[0037] In some embodiments, a group of guide mechanisms (not shown in the figure) is arranged on the inner side of the inlet and the outlet of the closed channel 11, the filament direction of the carbon fiber precursor filament bundle is guided by the guide mechanisms, and the jet ring 12 is between the two groups of guide mechanisms. In this way, under the jetting action of the pressure airflow of the jet ring 12, each carbon fiber precursor filament bundle forms a round shuttle shape with small ends and a large middle part, which can increase the gap between the filaments in the filament bundle, make the broken ends or the loose fibers more easily exposed and further blown into the closed channel 11, and increase the probability of adhesion of the broken ends or the loose fibers to the filament transmission 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 the central axis thereof, and the diameter of each jet hole is 1 mm to 3 mm. If the diameter of the jet hole is too small, the airflow impact is small, and it is difficult to blow the filament bundle 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 the filament is easily blown loose.

[0038] The scraping mechanism 22 further comprises a cutter seat 222, and the scraping cutter 221 is detachably connected to the cutter seat 222. Since the scraping cutter 221 is detachably connected to the cutter seat 222, the scraping cutter 221 can be conveniently replaced in time after long-time use and wear, thereby prolonging the service life of the scraping mechanism 22.

[0039] In a specific embodiment, the scraping cutter 221 is made of woven carbon fibers or chopped carbon fibers, which have the advantages of high strength and light weight.

[0040] The carbon fiber precursor filament hair online collection device is arranged after the drying densification device, the steam stretching device or the relaxation heat setting device in the carbon fiber precursor filament production line, so as to ensure sufficient opening and swelling of the carbon fiber precursor filament bundle, and further ensure reliable and accurate evaluation of the hair amount. In addition, it is worth emphasizing that the prior collection device of the present application arranged after the foregoing process can collect the hair in the whole process from spinning to collection, so that the evaluation of the hair amount carried in the precursor is more accurate and comprehensive.

[0041] Specifically referring to Figure 3 As shown in the figure, in some embodiments, the yarn guide mechanism comprises a plane yarn guide wheel 141 and a converging yarn guide wheel 142, wherein the converging yarn guide wheel 142 is arranged between the plane yarn guide wheel 141 and the air jet ring 12, and the plane yarn guide wheel 141, the converging yarn guide wheel 142 and the air jet ring 12 are sequentially and spacedly arranged along the length direction of the closed duct 11.

[0042] In the technical solution, the plane yarn guide wheel 141 guides the running path of the carbon fiber precursor filament bundle entering and being pulled out of the closed duct 11, so as to prevent the yarn path of the filament bundle in the closed duct 11 from deviating too much and causing wear due to contact with the wall surface of the closed duct 11, and to prevent the filament bundle from being hooked and broken. On the other hand, the converging yarn guide wheel 142 is arranged between the plane yarn guide wheel 141 and the air jet ring 12, which has the following advantages:

[0043] (1) Prevents the filament bundle from being pulled out: the converging guide wheel can limit the filament bundle within a certain range after the swelling treatment module, so as to prevent the filament bundle from being pulled out from the upper and lower guide wheels due to blowing, thereby preventing problems such as filament bundle hooking and breaking, and ensuring the continuity and stability of the production process;

[0044] (2) Optimizes the blowing effect: the filament bundle is more concentrated after converging, and the compressed air blown by the swelling treatment module can more uniformly and effectively act on the filament bundle, so that the filament bundle is dispersed into a spindle shape from the center, which ensures that the broken ends of the filament bundle can be better blown down, while maintaining the neat arrangement of the filaments, thereby improving the air treatment effect;

[0045] (3) If only a guide wheel of normal width is used, the tow will easily fall out of the guide wheel after being blown open; and for a tow of normal width, it is difficult to obtain a uniform and appropriate blowing force across the entire width of the tow, and the force may be too large or too small at the edge, causing the tow to be easily blown into disorder or split into several bundles;

[0046] (4) After passing through the shrinking guide wheel, the position of the yarn bundle is more accurate, which is conducive to the positioning of the subsequent steam drawing furnace or wire collecting machine, avoiding the deviation of the yarn bundle during operation and preventing the yarn bundles from interfering with each other.

[0047] In some embodiments, in the same guide wire mechanism, the carbon fiber precursor tow is staggered up and down on the guide wire wheel surfaces of the planar guide wire wheel 141 and the shrinkage guide wire wheel 142, respectively, so as to utilize the wrap angles between the tow and the different wheel surfaces of the planar guide wire wheel 141 and the shrinkage guide wire wheel 142, thereby improving the wire running stability of the tow. Figure 3 The orientation shown is for reference only, i.e. the front and back orientation on the paper.

[0048] See also Figure 3 As shown, the inner ring diameter of the jet ring 12 is D, the minimum distance between the jet ring 12 and the shrinking yarn wheel 142 is L, and D / (2L) is 5% to 20%. If D / (2L) is too small, it is difficult to blow the yarn bundle into a round shuttle shape and it is not easy to blow out the hairy yarns. On the contrary, if D / (2L) is too large, it is easy to blow the hairy yarns or blow the yarn bundle too large to be larger than the space of the puffing processing device 1, resulting in the yarn bundle being blown into a shuttle shape beyond the space of the puffing processing device 1, and the yarn bundle escaping from the yarn wheel in the yarn bundle.

[0049] The width of the enclosed passage 11 is S, and the S / D ratio is 1.5 to 3.0. If the S / D ratio is too small, it is not convenient to place the tow into the bulking processing device 1 during operation and is not conducive to collecting the hair in the enclosed passage 11. If the S / D ratio is too large, it wastes space and is not conducive to improving production efficiency. In a specific embodiment, the width of the flat godet 141 is N, and the N / D ratio is 0.8 to 1.0; and / or the width of the godet 142 is P, and the P / D ratio is 0.25 to 0.40.

[0050] In some embodiments, there are multiple filament transmission rollers 21 and scraping mechanisms 22, each of which corresponds to one another, and each of the filament transmission rollers 21 is staggered up and down, and each of the scraping mechanisms 22 is located on the opposite side of the filament wrapping surface of the filament transmission roller 21 corresponding thereto. The use of multiple groups of filament transmission rollers 21 and scraping mechanisms 22 can fully adhere to the fuzz on the outer surface of the carbon fiber filament bundle that forms a wrap angle with them, thereby ensuring the full collection of the fuzz, and thus ensuring the accuracy of the fuzzing amount evaluation results.

[0051] In some embodiments, the scraper 221 forms an inclined angle a with the vertical diameter line of the corresponding wire bundle transmission roller 21, and the angle a is 30-40°. The inclined direction of the scraper 221 is opposite to the rotating direction of the wire bundle transmission roller 21, so as to ensure the sufficient collection of the broken filaments adhered to the surface of the wire bundle transmission roller 21. In this technical solution, the inclined angle of the scraper 221 is optimized and limited, so as to prevent the decrease of the supporting force of the scraper 221 due to the too large angle, and prevent the increase of the space occupation and the blade consumption due to the too small angle.

[0052] In some embodiments, the wire bundle transmission rollers 21 are arranged alternately in the horizontal direction, the length direction of the closed duct 11 is the vertical direction, the wire bundle wrapping surface of the wire bundle transmission roller 21 closest to the outlet of the closed duct 11 is the lower surface of the wire bundle transmission roller 21, and the number of the wire bundle transmission rollers 21 is odd, so as to ensure the relatively low height of the wire bundle led out of the carbon fiber precursor filament broken filament online collection device, and facilitate the subsequent operation of the wire bundle.

[0053] According to the embodiments of the present application, a carbon fiber precursor filament broken filament amount evaluation method using the above carbon fiber precursor filament broken filament online collection device is also provided, which includes the following steps:

[0054] S1: controlling the continuous movement of the carbon fiber precursor filament in the closed duct 11 and the bulk filament collection device 2 corresponding to the bulking treatment device 1;

[0055] S2: controlling the jet ring 12 to spray the pressure airflow so that the carbon fiber precursor filament is bulking formed into a round shuttle shape, and controlling the cutting edge of the scraper 221 of the bulk filament collection device 2 to be tangent to the surface of the wire bundle transmission roller 21;

[0056] S3: collecting the broken filaments and / or broken ends in the closed duct 11 and on the scraper 221, and weighing to obtain the amount of broken filaments. Specifically, the foregoing closed ducts 11 and scrapers 221 can be manually swept and collected, and of course other collection methods such as negative pressure (vacuum) adsorption can also be used.

[0057] In the technical solution, in the process of the carbon fiber precursor filament bundle wire drawing, the filament bundle section running in the inflation treatment device 1 is subjected to pressure airflow (compressed air) injection to realize the opening of the filament bundle, that is, the inflation of the filament bundle. As a result, under the impact of the pressure airflow, the fibers in the filament bundle vibrate at a high frequency, and the loose fibers and broken ends in the filament bundle are at least partially transferred to the outside of the filament bundle, such as the outer surface of the filament bundle and the inner wall surface of the closed channel 11, so that the amount of loose fibers inside the filament bundle can be collected and measured. At the same time, since the loose fiber collection device 2 is arranged on the downstream side of the inflation treatment device 1, the loose fibers and broken ends on the outer surface of the filament bundle can be adhered by the filament bundle transmission roller 21 during the wire drawing process of the fiber filament bundle. At this time, the loose fibers and broken ends can be further collected by the scraper 221, so that the measurement of the amount of loose fibers of the carbon fiber precursor filament bundle is more accurate.

[0058] In some embodiments, after obtaining the amount of loose fibers, the following steps are further included:

[0059] S4: Detect the diameter of the collected loose fibers and / or broken ends (which can be detected by an optical microscope), and locate the position where the corresponding loose fibers and / or broken ends are generated according to the diameter. For example, in the case of using a wet spinning process or a dry-jet wet spinning process to manufacture the carbon fiber precursor filament, the diameter of the loose fiber formed in the carbon fiber precursor filament bundle by the process is generally in the range of 9-150 μm, and the diameter of the loose fiber formed in different production stages in different processes often has a large difference. Therefore, by detecting the diameter of the collected loose fibers and / or broken ends, it can be inferred which section in the corresponding production process the diameter of the loose fiber is generated (i.e., the position where the loose fiber is generated), and the matching degree or the stability of the running state of the spinning process can be evaluated, thereby providing strong support for improving the process application performance of the carbon fiber precursor and the carbon fiber.

[0060] In a specific embodiment, the aforementioned inflation treatment device 1 and loose fiber collection device 2 are assembled on the same mounting bracket to ensure the reliability and accuracy of the relative installation position between the two.

[0061] The device and method of the application are further described below in conjunction with two specific embodiments.

[0062] Example 1

[0063] A carbon fiber precursor loose fiber online collection device includes an inflation treatment device 1 and a loose fiber collection device 2.

[0064] The puffing treatment device 1 is located between the upper and lower transmission rollers, including a box (i.e. the aforesaid closed shell, the same below), a duct partition plate (i.e. the aforesaid partition plate 13, the same below), a yarn guide device (i.e. the aforesaid yarn guide mechanism, the same below) and a jet ring. The box is provided with a plurality of duct partition plates to divide the box into a plurality of ducts (i.e. the aforesaid closed duct 11, the same below). The position of each duct corresponds to the running position of the carbon fiber precursor, and the duct is provided with a yarn guide mechanism (two groups) and a group of jet rings.

[0065] The jet ring is a circular ring, and the inner diameter is D (15 mm); the distance between the yarn guide mechanism and the jet ring is L (60 mm); and D / (2L) is 12.5%.

[0066] The width of the duct is S (45 mm), and S / D is 3.0.

[0067] The inner wall of the jet ring is provided with a plurality of compressed air injection holes (i.e. the aforesaid jet holes, the same below), and the diameter of the jet hole is 2 mm, and the number is 6.

[0068] The yarn guide mechanism includes a flat yarn guide wheel and a concave yarn guide wheel (i.e. the aforesaid shrinkage yarn guide wheel), the width of the flat yarn guide wheel is N (12 mm), and N / D is 0.8; the width of the concave yarn guide wheel after shrinkage is P (5 mm), and P / D is 0.33.

[0069] The fluffy collection device 2 is arranged in the opposite direction of the tangent plane of the transmission roller and the carbon fiber precursor, including a scraping blade (i.e. the aforesaid scraper 221, the same below) and a blade support (i.e. the aforesaid blade seat 222, the same below), and the number of the fluffy collection device 2 is 5 groups.

[0070] The central axis of the blade support is a vertical direction, and coincides with the center point of the corresponding transmission roller (i.e. the aforesaid tow transmission roller 21, the same below).

[0071] The angle between the scraping blade and the central axis of the blade support is 35°.

[0072] The material of the scraping blade is woven carbon fiber.

[0073] The carbon fiber precursor fluff online collection device is arranged after the drying densification device, and the fluff amount of the carbon fiber precursor prepared by using the dry jet wet spinning process is evaluated, including the following steps:

[0074] S1: puffing treatment step, the carbon fiber precursor with a specification of 12K enters the corresponding spinning position duct of the puffing treatment device 1 through the upper transmission roller, and after entering the duct, the carbon fiber precursor passes through the yarn guide mechanism and the center of the jet ring to be blown off the fluff on the carbon fiber precursor under the action of compressed air in a circular shuttle shape, the puffing ratio of the carbon fiber precursor is D / (2L) 12.5%, and the compressed air pressure is 0.5 bar;

[0075] S2: collecting step, the unblown-off filaments adhered to the surface of the transmission roller of the carbon fiber precursor tape after the swelling treatment are scraped and collected by the scraping blade of the filament collection device 2;

[0076] S3: collecting and weighing step, after 12 hours, the filaments collected in the duct and on the scraping blade are collected; the weighing value is 0.72 g, and the filament amount M is 0.72 g.

[0077] The collected filaments are observed under an optical microscope, and the fiber diameter of the filaments is about 100 μm. The evolution law of the fiber diameter in the preparation process of the carbon fiber precursor is deduced, and it is inferred that the filaments come from the spinning dope stream breakage in the air section, and the reason is that there is an abnormal hole in the spinneret. After replacing the spinneret, the filament amount is evaluated again. After 12 hours, the filaments collected in the duct and on the scraping blade are collected; the weighing value is 0.12 g, the filament amount M is 0.12 g, and the running state is stable.

[0078] Example 2

[0079] The structure of the carbon fiber precursor filament on-line collection device is the same as that of Embodiment 1.

[0080] The carbon fiber precursor filament on-line collection device is arranged after the steam stretching furnace, and the filament amount of the carbon fiber precursor prepared by using the dry-jet wet spinning process is evaluated, including the following steps:

[0081] S1: swelling treatment step, the carbon fiber precursor with a specification of 12K enters the duct corresponding to the spinning position of the swelling treatment device 1 through the upper transmission roller, and after entering the duct, the fiber tape with the filaments is blown off in a circular shuttle shape under the action of compressed air through the center of the air jet ring, the swelling ratio D / (2L) of the precursor is 12.5%, and the compressed air pressure is 0.6 bar;

[0082] S2: collecting step, the unblown-off filaments adhered to the surface of the transmission roller of the carbon fiber precursor tape after the swelling treatment are scraped and collected by the scraping blade of the filament collection device 2;

[0083] S3: collecting and weighing step, after 12 hours, the filaments collected in the duct and on the scraping blade are collected; the weighing value is 0.34 g, and the filament amount M is 0.34 g.

[0084] The collected hair is observed under an optical microscope, and the fiber diameter of the hair is about 10 μm. The evolution of the fiber diameter during the preparation of the carbon fiber precursor is determined, and it is inferred that the hair is from the fiber breakage during the steam drawing process, which is caused by the low steam drawing pressure. After adjusting the steam drawing pressure, the hair amount is evaluated again. After 12 h, the hair collected in the channel and on the scraping blade is collected; the weight is 0.08 g, the hair amount M is 0.08 g, and the running state is stable.

[0085] Those skilled in the art can easily understand that the advantageous technical features of the above-mentioned modes can be freely combined and superimposed without conflict.

[0086] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An online collection device for carbon fiber precursor fibers, characterized in that: The invention comprises a puffing treatment device (1) and a hair collecting device (2), wherein the puffing treatment device (1) and the hair collecting device (2) are arranged front and back along the running direction of the carbon fiber precursor, wherein the puffing treatment device (1) comprises a closed channel (11) and an air jet ring (12) in the closed channel (11), the carbon fiber precursor is in the closed channel (11) and runs along the length extension direction of the closed channel (11), and the carbon fiber precursor passes through the air jet ring (12), and the air jet ring (12) can spray a pressurized air flow to open the carbon fiber precursor bundle running in the closed channel (11) to realize the carbon fiber precursor. The fuzz and / or broken ends in the filament bundle are at least partially transferred into the closed channel (11); the fuzz collecting device (2) includes a filament bundle drive roller (21) and a scraping mechanism (22) corresponding to the filament bundle drive roller (21), the scraping mechanism (22) includes a scraper (221), the blade of the scraper (221) is tangent to the roller surface of the filament bundle drive roller (21) so as to transfer the fuzz and / or broken ends adhering to the roller surface to the scraper (221), so as to collect the fuzz and / or broken ends in the closed channel (11) and on the scraper (221) and weigh the fuzz amount, so that the measurement of the fuzz amount of the carbon fiber precursor filament bundle is more accurate.

2. The online collection device for carbon fiber precursor hairs according to claim 1, characterized in that: The puffing treatment device (1) comprises a plurality of the enclosed corridors (11), and the length extension directions of the enclosed corridors (11) are arranged parallel to each other, and two adjacent enclosed corridors (11) are separated by a partition (13); and / or, a group of wire guide mechanisms are respectively arranged at the inner side of the inlet and outlet of the enclosed corridor (11), and the wire running direction of the carbon fiber precursor tow is guided by the wire guide mechanism, and the air jet ring (12) is located between the two groups of the wire guide mechanisms; and / or, the inner ring wall surface of the air jet ring (12) The scraping mechanism (22) has a plurality of air jet holes arranged around its central axis, and the diameter of each air jet hole is 1 mm to 3 mm; and / or, the scraping mechanism (22) further includes a knife seat (222), and the scraper (221) is detachably connected to the knife seat (222); and / or, the scraper (221) is made of woven carbon fiber or chopped carbon fiber; and / or, the carbon fiber precursor hair online collection device is arranged after the drying and densification device or after the steam drawing device or after the relaxation heat setting device in the carbon fiber precursor production line.

3. The online collection device for carbon fiber precursor hairs according to claim 2, characterized in that: The wire guide mechanism comprises a planar wire guide wheel (141) and a width-reduction wire guide wheel (142), wherein the width-reduction wire guide wheel (142) is located between the planar wire guide wheel (141) and the air jet ring (12), and the planar wire guide wheel (141), the width-reduction wire guide wheel (142) and the air jet ring (12) are sequentially arranged at intervals along the length extension direction of the closed corridor (11).

4. The online collection device for carbon fiber precursor hairs according to claim 3, characterized in that: In the same guide wire mechanism, the carbon fiber precursor tows are staggered up and down on the guide wire wheel surfaces of the planar guide wire wheel (141) and the shrinkage guide wire 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 shrinkage guide wire wheel (142) is L, and D / (2L) is 5% to 20%.

5. The online collection device for carbon fiber precursor hairs according to claim 4, characterized in that: The width of the enclosed corridor (11) is S, and S / D is 1.5 to 3.0; and / or the guide wheel surface width of the planar guide wheel (141) is N, and N / D is 0.8 to 1.0; and / or the guide wheel surface width of the shrinking guide wheel (142) is P, and P / D is 0.25 to 0.

40.

6. The online collection device for carbon fiber precursor hairs according to claim 2, characterized in that: There are multiple filament transmission rollers (21) and scraping mechanisms (22), each of which corresponds to one another, and each of the filament transmission rollers (21) is staggered up and down, and each of the scraping mechanisms (22) is located on the opposite side of the filament bundle covering surface of the corresponding filament transmission roller (21).

7. The online collection device for carbon fiber precursor hairs according to claim 6, characterized in that: An inclined angle a is formed between the scraper (221) and the vertical diameter line of the corresponding filament transmission roller (21), and a is 30° to 40°. The inclination direction of the scraper (221) is opposite to the rotation direction of the filament transmission roller (21).

8. The online collection device for carbon fiber precursor hairs according to claim 6, characterized in that: The bundle drive rollers (21) are alternately arranged up and down in the horizontal direction, the length direction of the closed corridor (11) is the vertical direction, and the bundle wrapping surface of the bundle drive roller (21) closest to the outlet of the closed corridor (11) is the lower surface of the bundle drive roller (21), and the number of the bundle drive rollers (21) is an odd number.

9. A method for evaluating the amount of carbon fiber precursor fuzz using the carbon fiber precursor fuzz online collection device according to any one of claims 1 to 8, characterized in that: The steps include: S1: controlling the carbon fiber precursor to continuously travel in the closed channel (11) corresponding to the puffing treatment device (1) and the hair collecting device (2); S2: controlling the jet ring (12) to eject a pressurized airflow so that the carbon fiber precursor is expanded into a round shuttle shape, and controlling the blade of the scraper (221) of the hair collecting device (2) to be tangent to the roller surface of the tow transmission roller (21); S3: collecting the hair and / or broken ends in the closed channel (11) and on the scraper (221), and weighing them to obtain the amount of hair.

10. The method for evaluating the amount of fuzz in carbon fiber precursor according to claim 9, wherein: After obtaining the amount of hair, the following steps are also included: S4: Detecting the diameter of the collected hair strands and / or broken ends, and locating the generation position of the corresponding hair strands and / or broken ends according to the diameter.

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