Apparatus and method for testing high performance fiber hairiness defects

Abstract

This invention discloses an apparatus and method for testing fuzz defects in high-performance fibers. The apparatus includes: a hot air field enclosed by a shell; a heat source for heating the hot air field; an air inlet section located at one end of the hot air field, communicating with the hot air field; an air inlet provided in the air inlet section, connected to the outlet of a circulating fan via a circulating air duct; a high-performance fiber sampling port connected to the air inlet section for fixing the high-performance fiber and suspending it within the hot air field; a sampling section located at the other end of the hot air field, communicating with the hot air field, and provided with several sampling ports; and an exhaust section connecting the sampling section to the inlet of the circulating fan, the exhaust section being provided with an external air source interface. This invention achieves quantitative detection of fuzz defects in high-performance fibers, providing accurate reference data for the production and evaluation of high-performance fibers, reducing the research, development, production, and application costs of high-performance fibers. Furthermore, the apparatus is simple, quick, convenient to operate, and has high testing accuracy.

Description

Technical Field

[0001] This invention belongs to the field of high-performance fiber process performance testing and evaluation technology, specifically relating to an apparatus and method for testing the fuzz defects of high-performance fibers. Background Technology

[0002] High-performance fibers generally refer to fibers with a strength greater than 17.6 cN / dtex and an elastic modulus greater than 440 cN / dtex. High-performance fibers are a new generation of special synthetic fibers developed by fiber science and engineering, possessing high strength, high modulus, and high-temperature resistance. They are mainly used in various fields of military and high-tech industries. In particular, they are used as reinforcements in composite materials, serving as the core component that bears the load. Common high-performance fibers include inorganic fibers such as glass fiber, carbon fiber, and basalt fiber; and inorganic fibers such as aramid fiber (aramid) and poly(p-phenylenebenzodioxazole) fiber (PBO).

[0003] The manufacturing process of high-performance fibers is quite challenging, involving complex and demanding conditions such as cyclization, crosslinking, high-temperature heat treatment, surface physicochemical treatment, and high-ratio drawing. These multiple processes can introduce various defects into high-performance fibers, such as fuzz, filaments, broken fibers, loops, and clumps (for simplicity, these defects are collectively referred to as fuzz defects). These defects can be masked by various auxiliaries applied during the finishing treatment of high-performance fibers, but they can also separate, become exposed, and accumulate during use, negatively impacting production efficiency and the performance of the final product.

[0004] High-performance fibers have a large number of fine monofilaments, resulting in very small hairs that are invisible to the naked eye. Therefore, manual inspection methods are insufficient for quantitative detection of hair defects in high-performance fibers. Traditional yarn hairiness testers are specialized instruments used to evaluate surface hairiness under tension, but they cannot effectively distinguish between inclusions within fiber bundles after sizing, or extra-long filaments and clumps. Therefore, based on the testing requirements for hairiness defects in high-performance fibers, there is an urgent need for a quantitative, simple, rapid method that eliminates the influence of sizing agents. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an apparatus and method for testing the fuzz defects of high-performance fibers. This method enables quantitative detection of fuzz defects in high-performance fibers, providing accurate reference data for the production and evaluation of high-performance fibers, reducing the research, development, production, and application costs of high-performance fibers. Furthermore, the apparatus is simple, quick, convenient, and has high testing accuracy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, an apparatus for testing defects in the fuzz of high-performance fibers is provided, comprising: a hot air field enclosed by a housing; a heat source mounted on the housing for heating the hot air field; an air inlet section connected to the housing and located at one end of the hot air field, the air inlet section communicating with the hot air field; the air inlet section having an air inlet connected to the outlet of a circulating fan via a circulating air duct; a high-performance fiber sampling port connected to the air inlet section for fixing and suspending the high-performance fibers within the hot air field; a sampling section connected to the housing and located at the other end of the hot air field, the sampling section communicating with the hot air field and having a plurality of sampling ports; and an exhaust section connecting the sampling section to the inlet of the circulating fan, the exhaust section having an external air source interface.

[0008] Furthermore, the air inlet includes a first air inlet and a second air inlet with an opening difference; the air inlet section is also provided with a wind speed regulating plate for adjusting the wind speed of the first air inlet and / or the second air inlet.

[0009] Furthermore, the high-performance fiber inlet is connected to the air inlet section by a snap-fit ​​connection.

[0010] Furthermore, the sampling port includes sampling port one and sampling port two, and sampling port one and sampling port two are respectively equipped with collection filters with different mesh sizes.

[0011] Furthermore, the mesh size of the collecting filter is 2 to 50 mesh.

[0012] Furthermore, it also includes an electrical control console for controlling the operation of the circulating fan and the temperature within the hot air field.

[0013] Secondly, a method for testing fuzz defects in high-performance fibers is provided, employing the apparatus for testing fuzz defects in high-performance fibers as described in the first aspect. The method includes: performing pre-test preparation and recording the initial mass m of the high-performance fiber to be tested. 0-1 The high-performance fiber to be tested is fed into the hot air field through the high-performance fiber inlet, and the device is started according to the set testing process to conduct the test. After the test, the high-performance fibers that have fallen off are collected from each sampling port and weighed, and recorded as the fiber weight at the sampling port. The initial mass m of the high-performance fiber is then used as the basis for the measurement. 0-1 The weight of the fibers at each sampling port is used to calculate the defect percentage; high-performance fibers collected from each sampling port are photographed, and the image data is analyzed and calculated using computer software to obtain relevant evaluation parameters for the fuzziness.

[0014] Furthermore, pre-test preparations include: fixing the device for testing high-performance fiber fuzz defects on a horizontal table indoors and maintaining constant indoor temperature and humidity; cleaning the circulating air duct and hot air field by blowing through an external air source interface; the sampling port includes sampling port one and sampling port two, with collection filters of different mesh sizes installed at sampling port one and sampling port two respectively; before installing the collection filters, the weight of the collection filters is recorded, wherein the weight of the collection filter at sampling port one is recorded as m. 1-1 The weight of the collection filter at the two sampling ports is recorded as m. 2-1 ; Adjust the circulating fan, set the test wind speed, and adjust the output temperature of the heat source.

[0015] Furthermore, based on the initial mass m of the high-performance fiber 0-1 The defect percentage is calculated based on the fiber weight at the sampling port. Specifically, the fiber weight at the sampling port includes the weight of the collection filter at one sampling port after the test, denoted as m. 1-2 The weight of the collection filter screens at the two sampling ports is denoted as m. 2-2 The remaining mass of the high-performance fiber at the high-performance fiber inlet after the test is recorded as m. 0-2 ;

[0016] The absolute mass of a type of feather defect is the change in mass before and after collection at a sampling port using the filter screen. The percentage of defects in this type of defect is:

[0017]

[0018] The absolute mass of the second type of feather defects is the change in mass of the filter screen before and after collection at sampling port two (8), and its defect ratio is:

[0019]

[0020] The total mass change of the reaction, i.e., the proportion of material loss, is:

[0021] Furthermore, computer software is used to analyze and calculate the image data to obtain relevant evaluation parameters for feathers, including but not limited to feather expansion size, diameter, number, feather frequency ratio, average value, and CV value.

[0022] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: This invention tests the type and quantity characteristics of fuzz defects in high-performance fibers under controlled temperatures; it collects fuzz defects at different process stages through a variable temperature field; it collects fuzz defects of different sizes through collection filters of different specifications; it evaluates the absolute weight of different types of fuzz defects by measuring the weight increase before and after collection; and it automatically analyzes the types of fuzz defects in high-performance fibers, including fuzz morphology and quantity proportion, using a high-magnification digital camera and auxiliary graphics software. The testing is highly accurate and the operation is simple and quick. This invention can provide quantitative evaluation parameters for the production and application of high-performance fibers, reducing costs in the research and development and application stages of high-performance fibers. Attached Figure Description

[0023] Figure 1 This is a front structural schematic diagram of a device for testing high-performance fiber fuzz defects provided in an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A schematic diagram of the side structure;

[0025] Figure 3 yes Figure 1 Top view;

[0026] Figure 4 This is a schematic diagram of the planar structure of the collection filter used in the embodiments of the present invention;

[0027] In the diagram: 1. High-performance fiber inlet; 2. Circulating fan; 3. Circulating duct; 31. First air inlet; 32. Second air inlet; 4. Wind speed regulating plate; 5. Hot air field; 6. Heat source; 7. Sampling port one; 8. Sampling port two; 9. External air source interface; 10. Electrical control console; 11. Collection filter. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0029] like Figures 1-4 As shown, an apparatus for testing defects in high-performance fiber fuzz includes:

[0030] The hot air field 5 is enclosed by the shell;

[0031] A heat source 6 installed on the housing for heating the hot air field 5;

[0032] An air inlet section is connected to the housing and located at one end of the hot air field 5. The air inlet section is connected to the hot air field 5. The air inlet section is provided with an air inlet, which is connected to the outlet of the circulating fan 2 through the circulating air duct 3.

[0033] Connected to the air inlet section, it is used to fix the high-performance fiber and suspend the high-performance fiber within the hot air field 5.

[0034] The sampling section is connected to the shell and located at the other end of the hot air field 5. The sampling section is connected to the hot air field 5 and has several sampling ports.

[0035] The exhaust section connects the sampling section to the inlet of the circulating fan 2, and the exhaust section is equipped with an external air source interface 9.

[0036] The air inlet includes a first air inlet 31 and a second air inlet 32 ​​with an opening difference. The opening difference between the first air inlet 31 and the second air inlet 32 ​​is used to achieve different wind speeds in the first air inlet 31 and the second air inlet 32. The air inlet section is also provided with a wind speed regulating plate 4 for adjusting the wind speed of the first air inlet 31 and / or the second air inlet 32.

[0037] The sampling ports include sampling port 7 and sampling port 8, and sampling port 7 and sampling port 8 are respectively equipped with collection filters 11 with different mesh sizes.

[0038] The high-performance fiber inlet 1 uses a quick-release buckle to quickly place a bundle of high-performance fibers of a fixed length into the hot air field 5 for heat treatment. The circulating fan 2 can be turned on and off by setting the electrical control panel 10, and the circulating air volume can be controlled by adjusting the speed of the circulating fan 2. The circulating air duct 3 achieves the left and right wind speed difference of the high-performance fiber sample in the hot air field through the opening difference of the left and right air inlets (first air inlet 31 and second air inlet 32), with a maximum wind speed of up to 10 m / s. The wind speed can be adjusted locally by adjusting the wind speed adjustment plate 4, which ultimately causes the high-performance fiber sample to shake under the airflow wind speed difference, thus removing fuzz defects. The temperature of the hot air field is controlled by the heat source 6 around the hot air field 5 under the TIC monitoring setting of the electrical control panel 10, with a maximum temperature of 1000℃ and an accuracy of 0.5℃. Due to the protective effect of the slurry applied to the fiber surface or the chemical reaction that occurs in the fiber at a certain processing temperature, the fuzziness of the high-performance fiber sample cannot be fully reflected by the airflow at room temperature alone. By adjusting the different process temperatures, the state under various conditions can be fully simulated.

[0039] Sampling port 1 (7) and sampling port 2 (8) can be quickly installed and used to collect metal collection filters 11 with different mesh sizes, ranging from 2 to 50 mesh, for collecting fuzz defects of different sizes; external air source interface 9 can be connected to other air sources, such as nitrogen, to perform targeted heat treatment based on the performance of high-performance fiber samples, and can also thoroughly clean the air duct.

[0040] The method for testing high-performance fiber fuzz defects using the aforementioned apparatus includes:

[0041] Prepare for the test and record the initial mass m of the high-performance fiber to be tested. 0-1 ;

[0042] The high-performance fiber to be tested is sent into the hot air field 5 through the high-performance fiber inlet 1, and the device is started according to the set test process to carry out the test.

[0043] After the test, the high-performance fibers that fell off from each sampling port were collected and weighed, and recorded as the fiber weight at the sampling port.

[0044] Based on the initial mass m of the high-performance fiber 0-1 Calculate the defect percentage based on the fiber weight at the sampling port;

[0045] High-performance fibers collected from various sampling ports are photographed, and the image data is analyzed and calculated using computer software to obtain relevant evaluation parameters for hairiness.

[0046] I. Preparations before the test

[0047] 1. Before testing, fix the device for testing high-performance fiber fuzz defects on a horizontal table indoors, and maintain a constant temperature and humidity in the test room. The room temperature is 20℃±2℃ and the relative humidity is 45%±3%.

[0048] 2. Open the electrical control panel 10, debug the circulating fan 2, and thoroughly clean the circulating air duct 3 and the hot air field 5 through the external air source interface 9;

[0049] 3. Install metal collecting filters 11 with different mesh sizes at sampling ports 7 and 8 respectively. In this invention, a collecting filter 11 with approximately 2-5 mesh is installed at sampling port 7, and a collecting filter 11 with approximately 50 mesh is installed at sampling port 8, to collect different feather defects. Before placing the collecting filters 11, weigh and record the weight of the collecting filters 11. The weight of the collecting filter at sampling port 7 is recorded as m. 1-1 The weight of the collection filter at sampling port 28 is recorded as m. 2-1 ;

[0050] 4. Using the electrical control panel 10, turn on the test circulating fan 2 and set the test wind speed;

[0051] 5. The output temperature of the heat source 6 can be adjusted through the electrical control console 10, and the temperature can be selected according to the material chemistry of the high-performance fiber being tested.

[0052] II. Defect Testing

[0053] 6. After the temperature stabilizes via the electrical control console 10, adjust the circulating fan 2 to its minimum speed. Then, send the high-performance fiber sample to be tested into the hot air field through the high-performance fiber inlet 1. Select 10-50 fiber bundles approximately 1m long and record the initial mass m of the high-performance fiber to be tested. 0-1 ;

[0054] 7. After adjusting the circulating fan 2 to the process air speed, perform hot airflow hair removal according to the different characteristics of the high-performance fibers being processed, such as the decomposition time of the applied sizing agent or the thermal reaction time of the fiber. After a period of hot airflow treatment, adjust the circulating fan 2 to the minimum air speed, turn off the heat source 6, and remove the collection filter 11 from sampling port 1 7 and sampling port 2 8 in two batches. Place the processed high-performance fiber samples in a desiccator.

[0055] III. Defect Analysis Calculation

[0056] 8. The weight of the heat-treated metal collection filter at sampling port 7 and sampling port 8 of the high-performance fiber sample was measured using an analytical balance. The weight of the collection filter at sampling port 7 after the test was completed was recorded as m. 1-2 The weight of the collection filter at sampling port 28 is denoted as m. 2-2 The remaining mass of the high-performance fiber at the high-performance fiber inlet 1 after the test is completed is denoted as m. 0-2 ;

[0057] The absolute mass of a type of feather defect is the change in mass before and after collection at the 7 sampling points using the filter screen. The percentage of defects in this type of defect is as follows:

[0058]

[0059] The absolute mass of the second type of feather defects is the change in mass of the filter screen collected at sampling port 2 before and after sampling. The proportion of defects is as follows:

[0060]

[0061] The total mass change of the reaction, i.e., the proportion of material loss (including chemical reaction), is:

[0062] The above three data points reflect the chemical reaction changes and hair defect damage that occur in high-performance fibers within a potential hot air field. They can also be used to further subdivide and sample a type of hair defect at different heat treatment times based on the reaction rate.

[0063] 9. Take pictures of the metal filter screen with feather defects at sampling port 7 using a high-definition digital camera. Analyze the image data using computer software to obtain relevant statistical values ​​such as feather expansion size, diameter, and quantity. Calculate the feather frequency ratio, average value, and CV value.

[0064] The apparatus and method for testing high-performance fiber hair defects described in this invention will be further explained below with reference to two specific embodiments.

[0065] Example 1: Testing for fuzz defects in a certain type of carbon fiber

[0066] 1. Before testing, fix the device for testing high-performance fiber fuzz defects on a horizontal table, and maintain a constant temperature and humidity in the testing room. The room temperature should be 20℃±2℃, and the relative humidity should be 45%±3%. Complete the preliminary equipment cleaning, filter measurement, and installation work.

[0067] 2. Turn on the electrical control panel, set the hot air field temperature to 350℃, and maintain the hot air field temperature stable for 5 minutes with a circulating hot air flow rate of 3m / s.

[0068] 3. Select three carbon fiber spindles of the same model and batch. In this example, T800 grade (12K) carbon fiber produced by Jiangsu Hengshen Co., Ltd. is selected. Take 40 flat carbon fiber bundles with a length of 1m from each spindle and send the sample into the hot air field at the lowest wind speed through the high-performance fiber inlet (the carbon fiber sample for one test is 40 carbon fiber bundles).

[0069] 4. With the hot air field temperature set at 350℃ and the circulating hot air flow at 3m / s, the airflow is treated for 30 minutes.

[0070] 5. The weights of the fuzz defects at sampling port 1 and sampling port 2 were measured to be 20 mg and 0.5 mg, respectively, and the fuzz defect loss rates at sampling port 1 and sampling port 2 were 1.1% and 0.5‰, respectively.

[0071] 6. Through analysis with a high-definition digital camera, the fuzz defects at the sampling port collection filter can be preliminarily divided into: 2 fuzz clumps with a diameter of more than 5 mm, 20 single fiber bundles with a length of more than 5 mm, 50 single fiber bundles with a length of 2-5 mm, and 4 long fuzz fibers with a length of more than 10 mm.

[0072] Implementation Example 2: Testing for fuzzy defects in a certain type of carbon fiber precursor - PAN precursor fibers

[0073] 1. Before testing, fix the device for testing high-performance fiber fuzz defects on a horizontal table, and maintain a constant temperature and humidity in the testing room. The room temperature should be 20℃±2℃, and the relative humidity should be 45%±3%. Complete the preliminary equipment cleaning, filter measurement, and installation work.

[0074] 2. Turn on the electrical control panel, set the hot air field temperature to 150℃, and maintain the hot air field temperature stable for 5 minutes with a circulating hot air flow rate of 0.4m / s.

[0075] 3. Select one spindle of a certain type of carbon fiber precursor - PAN precursor. The precursor is T700 grade (12K) carbon fiber precursor produced by Jiangsu Hengshen Co., Ltd. Take 40 flat PAN precursors with a length of 1m and send the sample into the hot air field at the lowest wind speed through the high-performance fiber inlet.

[0076] 4. With the hot air field temperature set at 150℃ and the circulating hot air flow at 0.4m / s, the airflow is processed for 10 minutes.

[0077] 5. The weight of the fuzz defects collected at one sampling port of filter screen one was 5 mg;

[0078] 6. Refill the collection filter at one sampling port. Under the condition of circulating hot air flow of 0.4 m / s, set the hot air field temperature to 230℃, 240℃, 250℃ and 260℃, and process for 10 minutes in the air flow treatment stage, for a total of 40 minutes.

[0079] 7. By measuring the collection filter at sampling port 1, the weights of the feather defects at sampling port 2 were 10 mg and 1 mg, respectively.

[0080] 8. Analysis using a high-definition digital camera:

[0081] In the collection of a single fuzz defect on the filter screen, it can be preliminarily divided into: 0 fuzz clumps with a diameter greater than 5mm, 40 single fiber bundles and filaments with a length greater than 5mm, 20 single fiber bundles with a length between 2-5mm, and 1 long filament with a length greater than 10mm.

[0082] Among the two fuzz defects collected from the filter screen, they can be preliminarily divided into: 1 fuzz ball with a diameter of more than 5 mm, 3 single fiber bundles and strands with a length of more than 5 mm, 40 single fiber bundles with a length of 2-5 mm, 5 long fuzz strands with a length of more than 10 mm, and 15 tar and dust impurities.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A device for testing defects in the fuzz of high-performance fibers, characterized in that, include: The hot air field enclosed by the shell (5); A heat source (6) installed on the housing for heating the hot air field (5); An air inlet section is connected to the housing and located at one end of the hot air field (5), and the air inlet section is in communication with the hot air field (5); the air inlet section is provided with an air inlet, and the air inlet is connected to the outlet of the circulating fan (2) through the circulating air duct (3); Connected to the air inlet section, it is used to fix the high-performance fiber and suspend the high-performance fiber inlet (1) in the hot air field (5). A sampling section connected to the housing and located at the other end of the hot air field (5), the sampling section being in communication with the hot air field (5), and the sampling section being provided with several sampling ports; The exhaust section connects the sampling section to the inlet of the circulating fan (2), and the exhaust section is provided with an external air source interface (9). The air inlet includes a first air inlet (31) and a second air inlet (32) with an opening difference; the air inlet section is also provided with a wind speed regulating plate (4) for adjusting the wind speed of the first air inlet (31) and / or the second air inlet (32). The sampling port includes sampling port one (7) and sampling port two (8), and sampling port one (7) and sampling port two (8) are respectively equipped with collection filters (11) with different mesh sizes.

2. The apparatus for testing high-performance fiber fuzz defects according to claim 1, characterized in that, The high-performance fiber inlet (1) is connected to the air inlet section by a snap-fit ​​connection.

3. The apparatus for testing high-performance fiber fuzz defects according to claim 1, characterized in that, The mesh size of the collection filter (11) is 2 to 50 mesh.

4. The apparatus for testing high-performance fiber fuzz defects according to claim 1, characterized in that, It also includes an electrical control console (10) for controlling the operation of the circulating fan (2) and the temperature within the hot air field (5).

5. A method for testing fuzz defects in high-performance fibers, characterized in that, The method of using the apparatus for testing high-performance fiber fuzz defects according to any one of claims 1 to 4 includes: Prepare for the test and record the initial mass m of the high-performance fiber to be tested. 0-1 ; The high-performance fiber to be tested is sent into the hot air field (5) through the high-performance fiber inlet (1), and the device is started and tested according to the set test process. After the test, the high-performance fibers that fell off from each sampling port were collected and weighed, and recorded as the fiber weight at the sampling port. Based on the initial mass m of the high-performance fiber 0-1 Calculate the defect percentage based on the fiber weight at the sampling port; High-performance fibers collected from various sampling ports are photographed, and the image data is analyzed and calculated using computer software to obtain relevant evaluation parameters for hairiness. Among them, based on the initial mass m of the high-performance fiber 0-1 Based on the fiber weight at the sampling port, the defect percentage is calculated as follows: The weight of the fiber at the sampling port, including the weight of the collection filter at sampling port 1 (7) after the test, is denoted as m. 1-2 The weight of the collection filter at sampling port two (8) is denoted as m. 2-2 ; The remaining mass of the high-performance fiber at the high-performance fiber inlet (1) after the test is completed is denoted as m. 0-2 ; The absolute mass of a type of feather defect is the change in mass of the filter screen before and after collection at sampling port 1 (7), and its defect percentage is: ; The absolute mass of the second type of feather defects is the change in mass of the filter screen before and after collection at sampling port two (8), and its defect percentage is: ; The total mass change of the reaction, i.e., the proportion of material loss, is: ; Where, m 1-1 The weight of the collection filter at sampling port 1 (7) before installation of the collection filter is m. 2-1 The weight of the collection filter at sampling port two (8) before the collection filter is installed.

6. The method for testing high-performance fiber fuzz defects according to claim 5, characterized in that, Preparations before testing include: The device for testing high-performance fiber fuzz defects was fixed on a horizontal table indoors, and the indoor temperature and humidity were kept constant. The circulating air duct (3) and hot air field (5) are purged and cleaned through the external air source interface (9); The sampling port includes sampling port one (7) and sampling port two (8). Different mesh size collection filters are installed in sampling port one (7) and sampling port two (8). Before installing the collection filters, the weight of the collection filters is recorded. Debug the circulating fan (2), set the test wind speed, and adjust the output temperature of the heat source (6).

7. The method for testing high-performance fiber fuzz defects according to claim 6, characterized in that, Computer software is used to analyze and calculate image data to obtain relevant evaluation parameters for feathers, including but not limited to feather expansion size, diameter, number, feather frequency ratio, average value, and CV value.

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