CN111289573A - Method for detecting quality of long carbon fiber bundle based on conductive information - Google Patents
Method for detecting quality of long carbon fiber bundle based on conductive information Download PDFInfo
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Abstract
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information, and belongs to the technical field of quality detection. The method comprises the following steps: continuously collecting the information of the long carbon fiber bundle, and judging the quality of the long carbon fiber bundle according to the collected information and the calculated information parameters; the information includes, but is not limited to, voltage, current, position, the information is continuous information; the information parameter is selected from at least one of resistance, resistivity, conductivity and voltage; comparing the obtained information parameter with the standard information parameter, judging that the area corresponding to the obtained information parameter has a defect when the absolute value of the obtained information parameter-standard information parameter/standard information parameter is greater than or equal to a defect judgment threshold value, and judging that the quality of the area corresponding to the obtained information parameter is qualified when the absolute value of the obtained information parameter-standard information parameter/standard information parameter is less than the defect judgment threshold value; during detection, the detection device and the long carbon fiber bundle have relative motion.
Description
Technical Field
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information, belonging to the technical field of quality detection, in particular to the technical field of continuous detection of non-metallic materials.
Background
Carbon fiber has a great number of excellent properties such as high specific strength, high specific modulus, high conductivity, high temperature resistance, corrosion resistance and the like, and is applied to the industrial fields of aerospace, ship transportation, vehicle production, military industry, national defense and the like in recent years. In 2018, in 2 months, the first hundred-ton grade T1000 carbon fiber production line is completely developed in China. The development of carbon fiber will be developed towards the diversification of technology in the future, and is both opportunity and challenge for the domestic carbon fiber industry.
The carbon fiber belongs to a brittle material, the diameter of a single wire is only 5-8 mu m, the defects of broken filaments, broken filaments and the like can be caused by direct clamping test, and the current national standard and standard-of-operation measuring methods, such as GB/T32993-2016 carbon fiber volume resistivity determination, QJ3074-1998 carbon fiber and composite material resistivity testing method, mainly take contact type discrete measurement as a main method, and have no relative movement between a sample and a probe, so that the measuring method is difficult to be applied to the measurement of long continuous carbon fibers. In the paper, "research on volume resistivity test method of carbon fiber bundle filament", two carbon fiber resistivity measurement methods, namely a linear sweep voltammetry method and an alternating current impedance method, are used, and due to the existence of contact resistance, linear fitting needs to be performed on acquired data, so that the contact resistance can be eliminated, and a more accurate resistivity value can be obtained. Patent CN105629068A discloses a method for measuring the volume resistivity of carbon fiber, which uses carbon fiber monofilament as a test sample to eliminate the measurement error caused by broken filaments and broken filaments during the test of bundled filament sample, but the measurement mode is still discrete measurement. When the invention is used for measuring the long carbon fiber bundle, the measuring mode is continuous measurement, the measuring area can be continuously changed, and the invention is easy to be compatible with the existing production line.
The detection device and the long carbon fiber bundle can move relatively, the information of the long carbon fiber bundle can be continuously collected, and systematic calculation and analysis are carried out based on the collected continuous information, so that defect judgment and quality detection are realized. The invention can detect the moving or static long carbon fiber bundle, can realize the continuous detection of the long carbon fiber bundle and the discrete detection, and has all the functions of the existing discrete detection technology.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a method for detecting the quality of a long carbon fiber bundle based on conductive information.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; continuously collecting the information of the long carbon fiber bundle, and judging the quality of the long carbon fiber bundle according to the continuously collected information and the calculated information parameters; the information comprises but is not limited to voltage, current and position, the information is continuous information, and the continuous information is information for continuously acquiring different positions of the measured long carbon fiber bundle; the information parameter is selected from at least one of resistance, resistivity, conductivity and voltage, and is calculated by voltage or current information and size information of the long carbon fiber bundle in the measured area; comparing the obtained information parameter with the standard information parameter, judging that the area corresponding to the obtained information parameter has a defect when the absolute value of the obtained information parameter-standard information parameter/standard information parameter is greater than or equal to a defect judgment threshold value, and judging that the quality of the area corresponding to the obtained information parameter is qualified when the absolute value of the obtained information parameter-standard information parameter/standard information parameter is less than the defect judgment threshold value; during detection, the detection device and the detected long carbon fiber bundle can move relatively.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the relative movement includes the following three cases: the detection device is static, and the detected long carbon fiber bundle moves and is mainly used for quality detection of the long carbon fiber bundle produced in the process; the detection device moves, and the measured long carbon fiber bundle is static and is mainly used for quality detection of the long carbon fiber bundle which is difficult to move; the detection device and the measured long carbon fiber bundle move at different speeds simultaneously and are mainly used for assisting in adjusting the information acquisition frequency and detecting a specific area; the relative movement is preferably a continuous relative movement.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the detection device is contacted with the long carbon fiber bundle through contact ends, wherein 2 contact ends for acquiring information are arranged; the contact area between any contact end and the long carbon fiber bundle is less than or equal to 100mm2Preferably 25mm or less2More preferably 5mm or less2More preferably 1mm or less2The selection of the parameters is related to the detection precision, and for high-end detection, the optimal scheme is preferably selected while physical performance is ensured, and certainly, in order to further improve the reliability of information, two interfaces for information acquisition are usedThe contact area of the contact end and the long carbon fiber bundle is equal.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; defining an area between the information acquisition contact ends as an information acquisition area, defining the opposite direction of the long carbon fiber bundle relative to the movement direction of the detection device as an information acquisition direction, defining the 1 st information acquisition contact end in the information acquisition direction as a positioning contact end, defining the state of acquiring the 1 st information as an initial state, and defining the position of the long carbon fiber bundle contacted with the positioning contact end as an information acquisition initial point (coordinate origin) in the initial state; the origin of coordinates can also be manually set and changed; after the coordinate origin is set, the positions of other points on the long carbon fiber bundle are represented by the distance between the long carbon fiber bundle and the coordinate origin.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the detection device automatically acquires information and calculates information parameters in the process of enabling the long carbon fiber bundle to enter and exit the information acquisition area, and automatically draws an information parameter-distance curve.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the ordinate of the information parameter-distance curve is an information parameter, and the information parameter is obtained by calculation according to the acquired voltage or current and the size information of the long carbon fiber bundle in the measured area; the calculation employs at least one of the following formulas:
resistance (Ω) is voltage (V) ÷ current (a);
resistivity (Ω · m) is resistance (Ω) × cross-sectional area (m)2) Length (m);
conductivity (S/m) ÷ 1 ÷ resistivity (Ω · m);
electrical conductivity (% IACS) — electrical conductivity (MS/m) ÷ 0.58.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the abscissa of the information parameter-distance curve is the distance between the contact position of the long carbon fiber bundle and the positioning contact end and the information acquisition starting point; the distance may be obtained by direct measurement, or by calculation based on time and velocity parameters.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the information parameter-distance curve reflects the quality information of the measured long carbon fiber bundle, deviates from normal and returns to normal, and enters and leaves the information acquisition area corresponding to defects. FIG. 1 is a schematic diagram of an information parameter-distance curve corresponding to a defect and a position of a long carbon fiber bundle, wherein a starting point (O point) of the information parameter-distance curve is obtained by calculation according to the 1 st acquired information, the distance between the corresponding position on the long carbon fiber bundle and the information acquisition starting point is 0, and the abscissa of the point is 0 mm; the state A is a state that 1 defect is about to enter the information acquisition area, when the measured long carbon fiber bundle moves from the initial state to the state A, no defect exists in the information acquisition area, an OA section correspondingly appears on an information parameter-distance curve, the information parameter is a normal parameter, the distance between the corresponding position of the point A on the long carbon fiber bundle and the information acquisition initial point is 50mm, and the abscissa of the point is 50 mm; the state B is a state that 1 defect just completely enters the information acquisition area, when the measured long carbon fiber bundle moves from the state A to the state B, the defect goes through the process of starting to enter and completely entering the information acquisition area, an AB section correspondingly appears on an information parameter-distance curve, the information parameter is an abnormal parameter, the distance between the corresponding position of a point B on the long carbon fiber bundle and the information acquisition starting point is 60mm, and the abscissa of the point is 60 mm; the C state is a state that the defect is about to leave the information acquisition area, when the measured long carbon fiber bundle moves from the B state to the C state, a BC section appears on an information parameter-distance curve, the distance between the corresponding position of a point C on the long carbon fiber bundle and the information acquisition starting point is 90mm, and the abscissa of the point is 90 mm; the state D is the state that the defect is leaving the information acquisition area, when the measured long carbon fiber bundle moves from the state C to the state D, the information parameters gradually return to the normal state, the distance between the corresponding position of the point D on the long carbon fiber bundle and the information acquisition starting point is 96mm, and the abscissa of the point is 96 mm.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; in a small number of cases, when the front end of the measured long carbon fiber bundle has a defect, the information parameter at the starting point of the information parameter-distance curve is abnormal, or when the tail end of the measured long carbon fiber bundle has a defect, the information parameter at the ending point of the information parameter-distance curve is abnormal.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the continuously acquired information can also comprise time information and temperature information, and when the acquired information comprises the time information, an information parameter-position-time curve can be obtained according to the information parameters, the position and the time.
Those skilled in the art can obtain the information and perform mathematical processing, theoretical calculation and physical meaning transformation according to the present invention, and the essence of the invention also belongs to the scope of the present invention.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the defect judgment threshold value is CrDenotes that when the information parameter is resistance and the unit used is Ω, C isrThe value of (a) is greater than or equal to 0.0001, preferably 0.0001 to 0.1, more preferably 0.0001 to 0.01, and even more preferably 0.0001 to 0.001; when the information parameters are replaced, the CrAnd carrying out corresponding conversion.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; quality analysis can be carried out according to the obtained information parameter-distance curve, the actual position of the defect on the information parameter and the defect length can be determined according to the abscissa of the starting point and the ending point of the abnormal information parameter regression normal, and the significance degree of the defect can be determined according to the difference value of the maximum value (or the minimum value) of the information parameter and the standard information parameter; FIG. 2 is a diagram showing an information parameter-distance curve, where the obtained information parameter is represented by Y and the standard information parameter is represented by YsIs represented by Ys±(Cr×Ys) Is the range of normal information parameters, and the error range mainly takes the measurement error of the system into consideration. As shown in FIG. 2, the obtained information parameter Y of the AB segment and BC segment satisfies | Y-Ys|＜Cr×YsReflecting that the corresponding long carbon fiber bundle region is free of defects; the information parameter Y of the C point satisfies | Y-Ys|＝Cr×Ys，Y＝YcThe obtained information parameter is at the critical value YcIndicating that a defect is about to enter the information acquisition area; the obtained information parameter of the CD segment exceeds the normal parameter range, | Y-Ys|≥Cr×YsGradually entering the information acquisition area corresponding to the defect; the value of the information parameter Y of the DF segment is relatively constant, and ideally, Y is equal to YmThe obtained information parameter is at the maximum value, and the corresponding defect is completely positioned in the information acquisition area; the acquired information parameters of the FG section continuously decrease, the corresponding defect gradually leaves the information acquisition area, the abscissa of the point F is the distance between the starting point of the contact between the defect and the positioning contact end and the information acquisition starting point, the abscissa of the point G is the distance between the ending point of the contact between the defect and the positioning contact end and the information acquisition starting point, and the difference value of the abscissas between the point F and the point G is the defect length; the information parameter Y of the G point satisfies | Y-Ys|＝Cr×Ys，Y＝YcThe obtained information parameter is at the critical value Yc(ii) a Y of GH and HI sections satisfies | Y-Ys|＜Cr×YsAnd the information parameter is in the normal parameter range, and reflects that the corresponding long carbon fiber bundle region is free of defects.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; when the obtained information parameter-standard information parameter/standard information parameter is greater than or equal to CrThen, the region detected by the judgment information includes at least 1 kind or 1 defect, and C is calculatedySaid C isy＝(Ym-Ys)÷YsSaid Y issIs a standard information parameter, said YmIs the maximum or minimum of the obtained information parameter, CyIs a defect determination factor. When the information parameter is voltage information and/or resistance and/or resistivity, CyMore than 0, the defect types include but are not limited to small volume content of the fiber, disordered fiber orientation and arrangement mode, small bundle number, broken filament, insufficient plating material, incomplete carbonization, CyLess than 0, defect types including but not limited to larger fiber volume content, larger bundle number and excessive plating materials; when the information parameter is selected from conductivity and/or electric conductivity, CyLess than 0, defect types including but not limited to small volume content of fiber, disordered fiber orientation and arrangement mode, small bundle number, broken filament, insufficient plating material, incomplete carbonization, Cy> 0, defect types including, but not limited to, large fiber volume content, large bundle countAnd excessive plating material.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the number of defects can be judged by analyzing the change condition of the information parameter-distance curve; generally, the obtained information parameter-distance curve is abnormal and returns to normal for 1 time, and the corresponding area of the long carbon fiber bundle can be judged to have at least 1 or 1 defect; in a few cases, the information parameter-distance curve is abnormal repeatedly and returns to normal or the change rate is increased or decreased suddenly, and at least 2 or 2 defects in the corresponding area of the long carbon fiber bundle can be judged; in rare cases, the information parameter-distance curve is abnormal and returns to normal repeatedly, and finally the normal parameter range can not be returned, and the condition that a large number of defects exist in the corresponding area of the long carbon fiber bundle or the corresponding area of the long carbon fiber bundle is a physical boundary is judged.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the method can detect the continuous occurrence of various defects, and judge whether the detected area continuously has 2 or more than 2 defects according to the slope of the information parameter-distance curve and the change condition of the slope if the information parameter-distance curve is abnormal and does not return for a long time or does not return until the detection is finished.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; defects that cause a change in the resistance of the long carbon fiber bundle, including but not limited to a change in the resistivity of the long carbon fiber bundle, a change in the total cross-sectional area, including a change in the cross-sectional area of the monofilament and/or a change in the number of bundles, are among the types of defects detectable by the present method; as shown in FIG. 3, when the defect is of a type in which the number of beams becomes small, the resistance becomes large as the number of beams becomes small, and YmIs the maximum value of the continuous resistance obtained, Ym＞Ys，CyIs greater than 0; as shown in FIG. 4, when the defect is of a type in which the number of beams becomes large, the resistance becomes small as the number of beams becomes large, and YmIs the minimum value of the continuous resistance obtained, Ym＜Ys，Cy＜0；YmAnd YsThe difference in (b) reflects the severity of the defect.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the standard information parameters are information parameters obtained by adopting a standard sample, the standard sample can be determined according to a standard, and the standard is a national standard, an industry standard or an enterprise standard.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the standard information parameter can also be determined by a user, or obtained by detection and/or calculation according to a standard sample determined by the user.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; when standard information parameters are acquired, the detection environment of the standard sample is the same as the actual detection environment, and the detection environment comprises but is not limited to temperature, pressure, humidity and noise.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the applicable temperature range is 10K-the melting temperature or the liquefaction temperature or the gasification temperature of the long carbon fiber bundle material to be measured.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the cross-sectional area of the long carbon fiber bundle is less than or equal to 200mm2Preferably 20mm or less2More preferably not more than 2mm2Still more preferably 0.2mm or less2More preferably 0.1mm or less2。
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the voltage or current information acquisition method includes, but is not limited to, a direct current four-point method, a single bridge method and a double bridge method.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the pitch of the 2 information collecting contact ends that are brought into contact with the long carbon fiber bundle is 1000mm or less, preferably 500mm or less, more preferably 100mm or less, still more preferably 50mm or less, and yet more preferably 15mm or less.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; during detection, the relationship among the information acquisition frequency, the relative movement speed between the long carbon fiber bundle and the detection device and the distance between the information acquisition contact ends is as follows: the relative movement speed ÷ information acquisition frequency < the information acquisition contact end distance can ensure that all areas of the long carbon fiber bundle can be detected, the acquired information samples are enough for analysis, and the smaller the relative movement speed is, the larger the acquisition frequency is, and the more the acquired information samples are.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; the information acquisition frequency is more than or equal to 1 time/10 seconds, preferably more than or equal to 1 time/second, and more preferably more than or equal to 10 times/second; the information acquisition frequency can also be set according to the length of the information acquisition area, and within a 10mm detection interval, the information acquisition frequency is more than or equal to 1 time, preferably more than or equal to 10 times, and more preferably more than or equal to 100 times; the information acquisition frequency can be optimized and adjusted according to the relative movement speed of the long carbon fiber bundle and the detection device and the characteristics of the information acquisition device.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; when the defect enters and leaves the information acquisition area, the corresponding information parameters have a certain mapping relation, and the information acquisition system can be checked according to the mapping relation; as shown in FIG. 2, the BD segment corresponds to the defect entering the information acquisition area, the FH segment corresponds to the defect leaving the information acquisition area, and the information parameters of the BD segment and the FH segment are ideally mapped to each other, i.e. for any point (X, Y) on the BD(X)) And mapped point on FH (X + l, Y)(X+l)) Existence of a relationship Y(X)'＝-Y(X+l)', wherein l is the length of the information acquisition region.
The invention relates to a method for detecting the quality of a long carbon fiber bundle based on conductive information; there are many defect determination methods, and any defect determination method based on the present invention is considered to fall within the scope of protection of the present patent.
Based on the detection idea of the invention, the directly obtained information or the information obtained by conversion has advantages in application under different materials and different precision requirements.
The invention also specially designs a device matched with the detection method; the device comprises P independent detection units, and the P units can be completely or partially contacted with the long carbon fiber bundle during detection; the detection unit can be static or move according to a designed track, the long carbon fiber bundle can also be static or move according to a designed track, and the detection unit and the long carbon fiber bundle can move relatively; and P is an integer greater than or equal to 1.
The invention relates to a device for detecting the quality of a long carbon fiber bundle based on conductive information; when the voltage information is detected by adopting a direct current four-point method, each detection unit comprises 4 wiring columns, a constant current providing module, a temperature measuring module and an information acquisition module; among the 4 wiring columns, 2 wiring columns at two ends are connected with the constant current providing module through a lead, and the 2 wiring columns in the middle are connected with the information acquisition module through leads; the temperature measurement module is connected with the information acquisition module. Preferably, the 4 terminal posts are divided into two groups and arranged in two rows.
The invention relates to a device for detecting the quality of a long carbon fiber bundle based on conductive information; the binding post is connected with a contact end, and the contact end comprises but is not limited to a conductive roller; the electrical resistivity of the wiring terminal and the contact end is less than or equal to 2 multiplied by 10-7Ω · m, preferably 4 × 10 or less-8Ω · m, more preferably 2 × 10 or less-8Ω·m；
Compared with the prior art, the invention provides a technical scheme for detecting the quality of the long carbon fiber bundle on line based on the conductive information, which has the technical advantages that:
1. the invention can realize the on-line continuous detection of the long carbon fiber bundle, and the detection device and the long carbon fiber bundle can have various relative movement modes, thereby having great practical value for the continuous on-line detection.
2. The invention has various detectable states, can be suitable for different detection places, can realize the online detection of different temperature environments, and can convert information parameters of different temperatures.
3. The invention can be used for detecting the defects causing resistance change, not only can detect the quality problem of the surface layer, but also can detect the internal defects, especially can detect the coexistence of 2 or more than 2 defects, and the prior art can not realize the function.
Drawings
FIG. 1 is a schematic diagram of an information parameter-distance curve corresponding to a defect and a position of a long carbon fiber bundle;
FIG. 2 is a schematic diagram of an information parameter-distance curve;
FIG. 3 is a schematic diagram of a resistance-distance curve of a defect with a decreasing beam number;
FIG. 4 is a schematic diagram of a resistance-distance curve of a defect with a decreasing beam number;
FIG. 5 is a schematic view (front side) of the detecting device of the present invention, wherein 1 and 4 are constant current input contacts, and 2 and 3 are information acquisition contacts;
FIG. 6 is a schematic view (side view) of the inspection apparatus of the present invention;
FIG. 7 is a cross-sectional view of a conductive roller of the inspection apparatus of the present invention;
FIG. 8 is a photograph of a test sample in example 1;
FIG. 9 is a voltage-distance curve of example 1;
FIG. 10 is a voltage-distance curve of example 2;
FIG. 11 is a photograph of a defect in example 2;
FIG. 12 is a resistance versus distance curve for example 3;
FIG. 13 is a photograph of a defect in example 3;
FIG. 14 is a voltage-distance curve of comparative example 1.
Detailed Description
In the following embodiments, the detection ambient temperature is 20 + -2 deg.C, and the contact area between the contact end and the long carbon fiber bundle is less than or equal to 10mm2. The detection system automatically acquires voltage information, position information and size information in the relative motion of the long carbon fiber bundle and the detection device, automatically calculates information parameters and draws an information parameter-distance curve.
The information parameter calculation adopts the following formula:
resistance (Ω) is voltage (V) ÷ current (a);
resistivity (Ω · m) is resistance (Ω) × cross-sectional area (m)2) Length (m);
conductivity (S/m) ÷ 1 ÷ resistivity (Ω · m);
electrical conductivity (% IACS) — electrical conductivity (MS/m) ÷ 0.58.
Example 1:
detection materials: t300 degummed carbon fiber with the length of 2000mm, and a sample object detection picture is shown in figure 8;
terminal spacing/information acquisition zone length: 150 mm;
inputting a constant current: 0.1A;
the motion mode is as follows: the sample moves, and the detection device is static;
the moving speed of the sample is as follows: 30 mm/s;
signal acquisition frequency: 30 times/s;
standard voltage: 2.135V;
FIG. 9 is a measured voltage-distance curve, Cr0.02, according to | measured voltage signal-standard voltage signal |/standard voltage signal < CrAnd judging whether the defect is present or not and detecting the product to be qualified.
Example 2
Detection materials: carbon fiber bundles with the length of 2000 mm;
terminal spacing/information acquisition zone length: 150 mm;
inputting a constant current: 0.1A;
the motion mode is as follows: the sample moves, and the detection device is static;
the moving speed of the sample is as follows: 25 mm/s;
signal acquisition frequency: 50 times/s;
standard voltage: 2.135V;
FIG. 10 is a graph of measured voltage versus distance, Cr0.02, according to the measured voltage signal-standard voltage signal/standard voltage signal ≥ CrJudging that 1 defect exists, abnormally increasing the voltage within the position range of 753mm-783mm, and entering an information acquisition area corresponding to the defect, YmWhen the voltage returns to normal within the position range of 903mm-933mm, the corresponding defect leaves the information acquisition area, the distances between the starting point and the ending point of the defect and the information acquisition starting point are 903mm and 933mm respectively, and the length of the defect area is 30 mm; defect determination factor Cy2.135 ═ 0.077, due to the decision factor Cy> 0, and the length of the defect region is medium, it is determined that the possible defect type is broken or broken filaments.
Further, it is found that the slope of the measured voltage signal-distance curve in the abnormal rising and falling stages is significantly changed, the slope is about 0.002V/mm in the 753mm-763mm rising stage, the slope is about 0.005V/mm in the 763mm-783mm rising stage, the slope is about-0.002V/mm in the 903mm-913mm falling stage, and the slope is about-0.005V/mm in the 913mm-933mm falling stage, and it is determined that the defect is formed by two types of defects, and the photograph shown in FIG. 11 shows that the defect is coexistence of broken filaments and broken filaments.
Example 3
Detection materials: carbon fiber multifilament yarn with length of 1500 mm;
terminal spacing/information acquisition zone length: 100 mm;
inputting a constant current: 0.1A;
the motion mode is as follows: the sample moves, and the detection device is static;
the moving speed of the sample is as follows: 30 mm/s;
signal acquisition frequency: 30 times/s;
standard resistance: 38.62 omega;
FIG. 12 is a graph of the obtained resistance-distance curve, Cr0.005, the obtained resistance-standard resistance/standard resistance ≧ CrJudging that 1 defect exists, abnormally reducing the resistance within the position range of 700mm-723mm, and entering an information acquisition area corresponding to the defect, YmThe resistance returns to normal within the position range of 800mm-823mm (38.10 omega), the corresponding defect leaves the information acquisition area, the distances between the position of the starting point and the position of the ending point of the defect and the position of the information acquisition starting point are 800mm and 823mm respectively, and the length of the defect area is 23 mm; defect determination factor Cy38.62 ═ 0.013 (38.10-38.62) ÷ 38.62, due to the decision factor CyLess than 0, and the length of the defect area is shorter, the possible defect types are judged to have larger fiber volume content, larger bundle number and the like, the corresponding position is found for specific analysis, the photo shown in FIG. 13 can not see macroscopic defects, and the common part are subjected to letter analysis according to the national standard GB/T3364-2008 carbon fiber diameter and root number test methodThe number of carbon fibers in the abnormal part was measured, and it was found that the number of carbon fibers in the normal part was about 12000 and the number of defects in the defect part was about 15000, and therefore the number of carbon fibers in the defect part was increased.
Comparative example 1:
the detection mode is as follows: carrying out segmented discrete detection;
detection materials: the same test sample as in example 2, carbon fiber bundle, length 2000 mm;
terminal spacing/information acquisition zone length: 150 mm;
inputting a constant current: 0.1A;
standard voltage: 2.135V;
FIG. 14 is a measured voltage signal-distance curve, Cr0.02, because the distance between the middle 2 binding posts is 150mm, the measurement needs 13 times, the result of each detection is the result of averaging 150mm sections, and according to the measured voltage signal-standard voltage signal/standard voltage signal |/standard voltage signal ≥ CrAnd judging that the region from 900mm to 1050mm has defects, and because only 13 discrete data points cannot determine the specific degree and length of the defect, the possible defect types cannot be judged. Example 2 detects defects in the region of 903mm to 933mm, two types of defects are analyzed, and the comparative example cannot detect the defects.
The comparative examples all show the disadvantages of discrete detection: the method has the advantages of needing to be divided in advance, having many detection times, being slow in detection speed, being unobvious in signals, being inaccurate in positioning, being incapable of further distinguishing types, being incapable of detecting the condition of extremely small defects and the like.
Claims (10)
1. A method for detecting the quality of a long carbon fiber bundle based on conductive information is characterized in that: continuously collecting the information of the long carbon fiber bundle, and judging the quality of the long carbon fiber bundle according to the continuously collected information and the calculated information parameters; the information comprises but is not limited to voltage, current and position, the information is continuous information, and the continuous information is information for continuously acquiring different positions of the measured long carbon fiber bundle; the information parameter is selected from at least one of resistance, resistivity, conductivity and voltage, and is calculated by voltage or current information and size information of the long carbon fiber bundle in the measured area; comparing the obtained information parameter with the standard information parameter, judging that the area corresponding to the obtained information parameter has a defect when the absolute value of the obtained information parameter-standard information parameter/standard information parameter is greater than or equal to a defect judgment threshold value, and judging that the quality of the area corresponding to the obtained information parameter is qualified when the absolute value of the obtained information parameter-standard information parameter/standard information parameter is less than the defect judgment threshold value; during detection, the detection device and the detected long carbon fiber bundle can move relatively.
2. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 1, wherein: the defect judgment threshold value is CrDenotes that when the information parameter is resistance and the unit used is Ω, C isrThe value of (a) is greater than or equal to 0.0001, preferably 0.0001 to 0.1, more preferably 0.0001 to 0.01, and even more preferably 0.0001 to 0.001; when switching between information parameters, the CrAnd carrying out corresponding conversion on the value of (A).
3. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 1 or 2, wherein: when the obtained information parameter-standard information parameter/standard information parameter is greater than or equal to CrThen, judging that the detected area at least comprises 1 or 1 defect; calculating CySaid C isy＝(Ym-Ys)÷YsSaid Y issIs a standard information parameter, said YmIs the maximum or minimum of the obtained information parameter, CyIs a defect judgment factor; when the information parameter is voltage information and/or resistance and/or resistivity, CyMore than 0, the defect types include but are not limited to small volume content of the fiber, disordered fiber orientation and arrangement mode, small bundle number, broken filament, insufficient plating material, incomplete carbonization, CyLess than 0, defect types including but not limited to larger fiber volume content, larger bundle number and excessive plating materials; when the information parameter is selected from conductivity and/or electric conductivity, Cy< 0, defect species include, but are not limited to, fibers with a small fiber volume content, fibersDisorderly orientation and arrangement mode, small bundle number, broken filaments, insufficient plating material, incomplete carbonization, CyAnd the defect types include but are not limited to larger fiber volume content, larger bundle number and excessive plating material.
4. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 1, wherein: the standard information parameters are information parameters of a standard sample, the standard sample can be determined according to standards, and the standards are national standards, industry standards or enterprise standards.
5. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 1, wherein: the standard information parameter can also be determined by a user, or obtained by detection and/or calculation according to a standard sample determined by the user.
6. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 4 or 5, wherein: when standard information parameters are acquired, the detection environment of the standard sample is the same as the actual detection environment, and the detection environment comprises but is not limited to temperature, pressure, humidity and noise.
7. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 1, wherein: the continuous information acquisition method includes, but is not limited to, a direct current four-point method, a single bridge method and a double bridge method.
8. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 1, wherein: the detection device is contacted with the long carbon fiber bundle through contact ends, wherein 2 contact ends for acquiring information are arranged; the contact area between any contact end and the long carbon fiber bundle is less than or equal to 100mm2Preferably 25mm or less2More preferably 5mm or less2More preferably 1mm or less2。
9. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 8, wherein: the pitch of the 2 information collecting contact ends that are brought into contact with the long carbon fiber bundle is 1000mm or less, preferably 500mm or less, more preferably 100mm or less, still more preferably 50mm or less, and yet more preferably 15mm or less.
10. The method for detecting the quality of the long carbon fiber bundle based on the conductive information as claimed in claim 1, wherein: during detection, the relationship among the information acquisition frequency, the relative movement speed between the detection device and the long carbon fiber bundle and the distance between the information acquisition contact ends is as follows: the relative movement speed is divided by the information acquisition frequency and is less than the distance between the information acquisition contact ends; the information acquisition frequency is equal to or greater than 1/10 seconds, preferably equal to or greater than 1/second, and more preferably equal to or greater than 10/second.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117368281A (en) * | 2023-10-26 | 2024-01-09 | 浙江大学 | Method and equipment for monitoring defects of carbon fiber composite material in-situ additive manufacturing in real time |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102096928A (en) * | 2011-01-27 | 2011-06-15 | 浙江工业大学 | Angle-based wandering track detection method in video surveillance |
| CN102661993A (en) * | 2012-04-10 | 2012-09-12 | 中南大学 | Nondestructive test device of reinforced concrete structure |
| CN103530885A (en) * | 2013-10-23 | 2014-01-22 | 北京倍肯恒业科技发展有限责任公司 | Detection and extraction algorithm for adaptive hierarchical edges of one-dimensional images |
| CN105723385A (en) * | 2013-10-30 | 2016-06-29 | 泰克托斯梦室私人有限公司 | Arrangement and method for inspecting an object, in particular a building |
| CN106404850A (en) * | 2016-11-08 | 2017-02-15 | 南京航空航天大学 | Method for testing anisotropic conductivity and interlaminar contact electrical resistivity of carbon fiber composite material |
| CN106770502A (en) * | 2017-01-03 | 2017-05-31 | 航天科工防御技术研究试验中心 | A kind of position finding and detection method of capacitance short-circuit failure |
-
2018
- 2018-12-07 CN CN201811495830.0A patent/CN111289573A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102096928A (en) * | 2011-01-27 | 2011-06-15 | 浙江工业大学 | Angle-based wandering track detection method in video surveillance |
| CN102661993A (en) * | 2012-04-10 | 2012-09-12 | 中南大学 | Nondestructive test device of reinforced concrete structure |
| CN103530885A (en) * | 2013-10-23 | 2014-01-22 | 北京倍肯恒业科技发展有限责任公司 | Detection and extraction algorithm for adaptive hierarchical edges of one-dimensional images |
| CN105723385A (en) * | 2013-10-30 | 2016-06-29 | 泰克托斯梦室私人有限公司 | Arrangement and method for inspecting an object, in particular a building |
| CN106404850A (en) * | 2016-11-08 | 2017-02-15 | 南京航空航天大学 | Method for testing anisotropic conductivity and interlaminar contact electrical resistivity of carbon fiber composite material |
| CN106770502A (en) * | 2017-01-03 | 2017-05-31 | 航天科工防御技术研究试验中心 | A kind of position finding and detection method of capacitance short-circuit failure |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117368281A (en) * | 2023-10-26 | 2024-01-09 | 浙江大学 | Method and equipment for monitoring defects of carbon fiber composite material in-situ additive manufacturing in real time |
| CN117368281B (en) * | 2023-10-26 | 2024-04-12 | 浙江大学 | Method and equipment for monitoring defects of carbon fiber composite material in-situ additive manufacturing in real time |
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