Preparation method and application of fiber section sample

Abstract

The invention relates to a preparation method and application of a fiber section sample, and relates to the field of fiber detection. The preparation method comprises the following steps: gathering a plurality of fibers to be subjected to sample preparation, winding by preset mass to obtain skein, fixing one end of the skein, applying force to the other end of the skein to flatten the skein, smearing glue, flattening the area coated with the glue in the skein, and drying until the glue is cured to obtain the fiber section sample. The preparation method can be used for efficiently and directly preparing a fiber cross-sectional view for finer and higher-profile-degree fibers. The preparation method is easy to operate in the whole process, high in adaptability to fibers with different fineness degrees, high in adaptability to fibers with different profile degrees, good in adaptability to elastic fibers, high in repeatability and high in fiber section slice imaging rate. Compression on the profiled fibers can be reduced to the maximum extent, and the accuracy of profiled degree calculation is improved.

Description

Technical Field

[0001] The invention relates to the field of fiber detection, and in particular to a method for preparing a fiber cross-section sample and application thereof. Background Art

[0002] The fiber cross section is the flat cross section obtained after the slicer or blade cuts the fiber perpendicular to the fiber axis. This thin slice is observed under a projector or microscope to identify fiber varieties and observe fiber shapes, such as shaped fibers, shaped yarn shaped degree, composite fibers, etc. Observing the cross-section of the fiber during the production process can directly and clearly indicate the fiber molding situation and efficiently feedback production information to the adjustment of the production process. With the development of the times, the production technology of chemical fiber, regenerated fiber, etc. has been improving, the fiber line density is getting lower and lower, and the shaped degree is getting higher and higher. For this type of fiber, the conventional method of the Hastelloy slicer using an optical microscope is to gently press the sample and then add a small amount of 3% collodion. This method of sample preparation can easily cause the ultra-fine shaped yarn to deform; and the liquid nitrogen cross-section sample preparation method using an electron microscope has a clear fiber cross-section diagram, but the operation time is long and the feedback speed is slow. Summary of the invention

[0003] In view of the above problems, the present invention provides a method for preparing a fiber cross-section sample, which can efficiently directly produce a fiber cross-section image for a thinner fiber with a higher degree of irregularity. The preparation method is easy to operate throughout the entire process, and has strong adaptability to fibers of different finenesses, fibers of different degrees of irregularity, and elastic fibers. It has high repeatability and a high fiber cross-section slice imaging rate. It can minimize the compression of irregular fibers and improve the accuracy of irregularity calculation.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a method for preparing a fiber cross-section sample, comprising the following steps: bringing together a number of fibers to be sampled, winding a predetermined mass to obtain a skein, fixing one end of the skein, applying force to the other end of the skein to flatten the skein, applying glue, flattening the area of ​​the skein coated with glue, and drying until the glue is solidified to obtain a fiber cross-section sample.

[0005] The conventional fiber cross-section sample preparation method is to straighten the fiber by hand, then put it horizontally into the sample slot of the Hastelloy slicer, press it, and then add collodion. The whole process is operated on a horizontal plane. However, this conventional sample preparation method cannot adapt to the ultra-fine and / or special-shaped fibers produced by the new technology today. If ultra-fine and / or special-shaped fibers are processed by the above conventional sample preparation method, they are easily compressed and deformed. If the fiber itself has color or is not transparent, the light transmittance of the slice will be even less, resulting in the prepared fiber cross-section sample being dim and unclear under an optical microscope. In addition, the conventional sample preparation method is to solidify and shape the collodion after clamping the sample. For ultra-fine and / or special-shaped fibers, this operation will have a chance of failure. If the sample slot clamps too many samples, the fiber will be too tight and deformed, and the cross-section will be black; if the sample slot clamps too few samples, the whole piece will fall apart when the cross section is cut, and the sample can only be re-prepared, resulting in low efficiency. Therefore, the inventors propose to first take samples according to a predetermined mass, flatten them, apply glue to solidify them before clamping the samples, shape them in advance, and then slice them. This can be better applied to ultrafine and / or special-shaped fibers, and the fiber cross-section slice imaging rate is higher, and there is basically no need to re-sampling and test. Moreover, the preparation method of this case can minimize the compression of the fiber to the greatest extent and improve the calculation accuracy of the profile parameter of the profiled fiber (profile = (1-radius of the inscribed circle of the profiled section / radius of the circumscribed circle of the profiled section) × 100). The traditional sample preparation method has poor control over the sample quantity, and the ultrafine profiled fiber is easily compressed and deformed. Once compressed, the circumscribed circle radius of the profiled section cannot be measured. In this case, the sample is cured in the slicer instead of being cured first and then sampled. The overall volume of the sample is controlled from the moment of sampling so that its volume can just enter the slice sample slot. During curing, the glue can be evenly distributed between the fibers, making the cured sample less likely to be cut apart by the blade. The final fiber cross section is not easy to deform, which also improves the accuracy of the technical researcher's calculation of the fiber profile.

[0006] In one embodiment, the glue-coated area is close to the end where the force is applied.

[0007] In one embodiment, the predetermined mass is 1.5-2.4 g.

[0008] In one embodiment, the hank is fixed by hanging one end of the hank and the hank is flattened by applying a downward force to the other end of the hank.

[0009] In one embodiment, the downward force is applied by hanging a weight at the other end of the hank.

[0010] In one embodiment, the mass of the weight is 2.5-25g.

[0011] In one embodiment, when the fiber to be sampled is a non-elastic and non-shaped fiber, the mass of the weight is 2.5-5g.

[0012] In one embodiment, when the fiber to be sampled is elastic fiber or shaped fiber, the mass of the weight is 20-25 g.

[0013] In one embodiment, the glue includes PVAL glue, and the drying temperature is 25-35°C.

[0014] The above-mentioned PVAL glue can greatly increase the amount of light transmittance left between the fibers.

[0015] In one embodiment, the slicing is achieved using a Haughey slicer.

[0016] The invention also provides a fiber cross-section sample obtained by the preparation method.

[0017] In one embodiment, the fibers include elastic fibers, shaped fibers, or non-elastic non-shaped fibers.

[0018] The present invention also provides a method for detecting a fiber cross section, comprising the following steps: slicing the fiber cross section sample to obtain a sliced ​​sample, and observing the sliced ​​sample using a microscope.

[0019] In one embodiment, the slicing is achieved using a Haugh slicer.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention discloses a method for preparing a fiber cross-section sample and its application. The method can efficiently produce a fiber cross-section diagram for finer fibers with higher profiles. The method is easy to operate throughout the entire process, and has strong adaptability to fibers of different finenesses, fibers of different profiles, and elastic fibers. It has high repeatability and a high imaging rate for fiber cross-section slices. The method can minimize the compression of profiled fibers and improve the accuracy of profile calculation. The method only takes less than 0.5 hours from fiber sample preparation to cross-section cutting, and the length of the cross-section cutting time is very important for the trial production process of new samples and new processes. The shorter the cross-section cutting time, the more convenient it is for process technicians to adjust process parameters in time according to the cross-section diagram. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The structure diagram of the Hastelloy slicer is shown in FIG. 1 , wherein 1 is a metal plate, 2 is a metal plate, 3 is a precision screw seat, 4 is a screw, 5 is a pin, and 6 is a screw seat;

[0023] Figure 2Schematic diagram of the structure of adding weights after the skein 1 is coated with glue in the embodiment, wherein 7 is the skein, 8 is the area coated with glue, and 9 is the weight;

[0024] Figure 3 is a micrograph of the fiber cross-section sample 1A in the embodiment (magnified 200 times);

[0025] Figure 4 This is a micrograph of the fiber cross section sample 1B in the embodiment (magnified 200 times);

[0026] Figure 5 This is a micrograph of the fiber cross-section sample 2 in the embodiment (magnified 100 times);

[0027] Figure 6 This is a micrograph of the fiber cross-section sample 2 in the embodiment (magnified 200 times);

[0028] Figure 7 This is a micrograph of the fiber cross-section sample 2 in the embodiment (magnified 500 times);

[0029] Figure 8 is a micrograph of the fiber cross-section sample 3A in the embodiment (magnified 500 times);

[0030] Fig. 9 This is a micrograph of the fiber cross section sample 3B in the embodiment (magnified 500 times);

[0031] Fig.10 This is a micrograph of the fiber cross section sample 4A in the example (magnified 200 times). DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0034] source:

[0035] Unless otherwise specified, the reagents, materials, and equipment used in this example are all commercially available; the experimental methods are all conventional experimental methods in the art unless otherwise specified.

[0036] Example

[0037] 1. A method for preparing a fiber cross-section specimen.

[0038] 1. Combine several yarns to be sampled into a cluster of yarns according to the designed number of roots, wind a certain length (integer turns) of yarn on the yarn length measuring instrument, and after reaching the predetermined mass (1.5g to 2.4g), remove the yarn skein from the length measuring instrument. The yarn skein length is about 500mm. Hang the skein and apply downward force according to different yarns to make the skein flat. In this embodiment, the downward force is achieved by hanging weights, and the mass of the weights is 2.5-25g. Evenly apply glue with PVAL as the main component on the lower half of the skein (i.e., close to the end where the downward force is applied) to make it fully penetrate into each fiber, slightly flatten the part coated with glue, put it into the slice sample slot for easy fixation, and then blow it dry with wind at a temperature of 25-35℃. After reaching a stiff state, it is the processed sample to be tested.

[0039] In the above process of flattening the skein, different weights are selected to apply downward pressure according to the elasticity, profile and fineness of the fiber to keep the skein neatly and vertically drooping. Specifically, for non-elastic and non-profiled fibers, the mass of the yarn wound on the yarn length measuring instrument can be heavier. After many experiments, the inventors have concluded that the skein of non-elastic and non-profiled fibers is below 2.4g, and the downward pressure (i.e., hanging weights) is above 2.5g and below 5g, which can achieve neat verticality; elastic fibers or profiled fibers, because their own structure is not necessarily a neat columnar body, need to appropriately reduce the mass of the yarn wound on the yarn length measuring instrument to reduce the volume of the sample after molding, avoid being compressed in the sample slot of the slicer during testing, resulting in deformation and distortion of the sample. After many experiments, the inventors have concluded that the skein of elastic fibers or profiled fibers needs to be above 1.5g, and in addition, elastic fibers need to apply a certain downward pressure to make the inside of the sample neatly and vertically. The greater the elasticity, the greater the downward pressure needs to be applied, and it is recommended to be above 20g and below 25g. The best drying temperature is 30℃ and should not exceed 35℃. If the temperature is too high, the shaped wire will easily deform and the image will be distorted.

[0040] 2. Perform cross-section slicing on the sample to be tested (the slicing operation is performed by a Hastelloy slicer, the structure of which is as follows Figure 1 ), as follows:

[0041] Loosen the screw 4 on the slicer, remove the pin 5, turn the screw seat 6 to a position perpendicular to the metal plate 2, and pull out the metal plate. Place the sample to be tested processed by the present invention into the sample slot of the metal plate 2, insert the metal plate 1, gently press the sample, and use a sharp blade to cut off the fibers on the front and back of the metal plate. Turn the screw seat 6 to the working position and position it with the pin 5. Tighten the screw seat 4, rotate the precision screw seat 3 clockwise, so that the test sample slightly protrudes from the surface of the metal plate, and use a sharp blade to cut the first piece of sample along the surface of the metal plate. Repeat the sample cutting operation steps until a thin and uniform sample slice is obtained. Place the sample slice on a glass slide and cover it with a coverslip for microscopic observation.

[0042] 2. Use the conventional sample preparation method in step 1 of this embodiment to make a cross-sectional view of the shaped nylon yarn.

[0043] The linear density of the nylon single yarn used is 42dtex, the number of roots is 24, it is a profiled yarn, and it is fully dull.

[0044] 1. Prepare the sample using the method of step 1 of this embodiment.

[0045] Use a yarn length measuring instrument to wind 524 turns of nylon yarn with a mass of 2.2g to obtain skein 1, tie a knot at the end of skein 1 and hang it up. Hang a 2.5g weight at the bottom of the hung skein to make the skein stand straight and straight, use glue with PVAL as the main component to evenly apply it on the lower half of the skein to make it fully penetrate between the fibers, and gently flatten it to make it elliptical cylinder-like, and then dry it at 30℃ until it is hard and straight, to obtain fiber cross-section sample 1A.

[0046] like Figure 2 As shown, it is a schematic diagram of the structure after glue is applied to the skein 1 and weights are applied.

[0047] 2. Prepare samples using conventional sample preparation methods.

[0048] Using the conventional method of the Hastelloy slicer of an optical microscope: lightly compress the sample, and then add a small amount of 3% collodion to prepare the fiber cross-section sample 1B.

[0049] 3. Use the conventional sample preparation method in step 1 of this embodiment to make a cross-sectional view of the shaped nylon yarn.

[0050] The linear density of the nylon single yarn used is 86dtex, the number of roots is 48, it is shaped yarn, and semi-bright.

[0051] 1. Prepare the sample using the method of step 1 of this embodiment.

[0052] Use a yarn length measuring instrument to wind 290 turns of nylon yarn with a mass of 2.5g to obtain skein 2, tie a knot at the end of skein 2 and hang it up. Hang a 2.5g weight at the bottom of the hung skein to make the skein stand straight and straight, use glue with PVAL as the main component to evenly apply it on the lower half of the skein to make it fully penetrate between the fibers, and gently flatten it to make it elliptical cylinder-like, and then dry it at 30℃ until it is hard and straight, to obtain fiber cross-section sample 2.

[0053] 4. Use the conventional sample preparation method in step 1 of this embodiment to make a cross-sectional view of the shaped nylon yarn.

[0054] The process of making a cross-sectional diagram of ultrafine nylon yarn uses a nylon single yarn with a linear density of 20dtex, a root count of 64, non-profiled yarn, and full dullness.

[0055] 1. Prepare the sample using the method of step 1 of this embodiment.

[0056] Use a yarn length measuring instrument to wind 1000 turns of nylon yarn with a mass of 2.0g to obtain skein 3, tie a knot at the end of skein 3 and hang it up. Hang a 5g weight at the bottom of the hung skein to make the skein straight and vertical downward. Use glue with PVAL as the main component to evenly apply it to the lower half of the skein to make it fully penetrate between each fiber, and gently flatten it to make it elliptical cylinder-like, and then dry it at 30℃ until it is hard and straight, to obtain fiber cross-section sample 3A.

[0057] 2. Prepare samples using conventional sample preparation methods.

[0058] Using the conventional method of the Hastelloy slicer of an optical microscope: lightly compress the sample, and then add a small amount of 3% collodion to prepare the fiber cross-section sample 3B.

[0059] 5. Use the conventional sample preparation method in step 1 of this embodiment to make a cross-sectional view of the shaped nylon yarn.

[0060] The cross-sectional diagram of the elastic nylon yarn is shown in the process of making the nylon single yarn with a linear density of 62dtex, a root number of 48, a profiled yarn, semi-bright, and a tensile elastic recovery rate of more than 50%.

[0061] 1. Prepare the sample using the method of step 1 of this embodiment.

[0062] Use a yarn length measuring instrument to wind 258 turns of nylon yarn with a mass of 1.6g to obtain skein 4, tie a knot at the end of skein 4 and hang it up. Hang a 25g weight at the bottom of the hung skein to make the skein straight and vertical downward, use glue with PVAL as the main component to evenly apply it on the lower half of the skein to make it fully penetrate between each fiber, and gently flatten it to make it elliptical cylinder-like, and then dry it at 30℃ until it is hard and straight, to obtain fiber cross-section sample 4A.

[0063] 2. Prepare samples using conventional sample preparation methods.

[0064] Using the conventional method of the Hastelloy slicer of an optical microscope: lightly compress the sample, and then add a small amount of 3% collodion to prepare the fiber cross-section sample 4B.

[0065] 6. Slice the above fiber cross-section samples and observe them under a microscope.

[0066] The fiber cross-section sample is sliced ​​using a Hastelloy slicer to obtain a sliced ​​sample, and the sliced ​​sample is observed using a microscope.

[0067] 1. Fiber cross section specimen 1A Figure 3 As shown, the fiber cross-section sample 1B is as follows Figure 4 shown.

[0068] The method in this case minimizes the compression of the fiber and improves the calculation accuracy of the profile parameter of the profiled fiber (profile = (1-profile section inscribed circle radius / profile section circumscribed circle radius) × 100). From the comparison of the sliced ​​samples observed through a microscope, it can be seen that the conventional method compresses the profiled wire very seriously, and some parts have even been compressed to blur. The insufficient space between the wires leads to poor light transmittance and even less clear graphics. This method has poor control over the sample amount, and the ultra-fine profiled fiber is easily compressed and deformed. Once compressed, the circumscribed circle radius of the profiled section cannot be measured, which reduces work efficiency.

[0069] In this case, the sample is cured in the slicer before being solidified. The overall volume of the sample is controlled from the moment of sampling so that its volume can just fit into the slice sample slot. During solidification, PVAL glue can be evenly distributed between the fibers. PVAL glue greatly increases the amount of light transmittance between the fibers and makes the solidified sample less likely to be cut apart by the blade. The final fiber cross-section is not easily deformed, which also improves the accuracy of technical researchers' calculation of fiber irregularity.

[0070] 2. Fiber cross section specimen 2 Figure 5 , 6 , as shown in Figure 7.

[0071] It can be seen from the microscope observation results of fiber cross-section sample 2 that, compared with the conventional fixed cross-section in which the wires are tightly attached to each other, the present invention can achieve a certain space between the wires, and the special-shaped wires can be clearly seen at 100 times the whole, 200 times the part, and 500 times the individual molding. This improves the tolerance of the observation magnification of the special-shaped fiber cross-section, and can greatly improve the feedback efficiency and feedback quality of production information during the production process.

[0072] 3. Fiber cross section specimen 3A Figure 8As shown, the fiber cross-section sample 3B is as follows Fig. 9 shown.

[0073] Optical microscopes are limited by their working principles. The greater the magnification, the less light the lens transmits, and the darker the image. If the silk itself is not completely transparent, the image will be even worse. However, when working with ultrafine fibers, it is impossible to see clearly at a magnification of less than 300 times. Only high magnifications can be used, which require magnifications of 500 times or more.

[0074] Depend on Figure 8 It can be seen that when the cross-section of 20dtex, 62F, matt-like ultrafine fiber is made by conventional methods, the cross-section is dull and blurred, while the cross-section made by the present invention has increased light transmittance and bright, sharp and clear images because the filaments are not tightly connected. The present invention has higher adaptability to filaments.

[0075] 4. Fiber cross section specimen 4A Fig.10 As shown, fiber cross-section sample 4B failed to be prepared using the conventional sample preparation method.

[0076] The reason why the fiber cross-section sample 4B prepared by the conventional sample preparation method failed is that it is difficult to make a cross-section of a highly elastic fiber by conventional methods. Due to the elasticity of the elastic fiber itself, when it is compressed by the slicer and then pushed out and cut by the precision screw seat, the external stress applied to the fiber itself by the slicer suddenly disappears. The unbalanced internal and external stresses will easily cause the slice to fall apart and not form, making it difficult to make a cross-sectional slice. Fig.10 It can be seen that the present invention will not give the elastic wire too much external stress when making samples, and will fix it in a state with as little compression as possible. It will not spread out when slicing the cross section, and the slices made are also clear and restore the cross-sectional conditions of the wire itself, greatly improving the work efficiency of cross-sectional production.

[0077] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a fiber cross-section sample, characterized in that: The following steps are involved: Put a number of fibers to be sampled together, wind a predetermined mass to obtain a skein, fix one end of the skein, apply force to the other end of the skein to flatten the skein, apply glue, flatten the area of ​​the skein coated with glue, and dry until the glue solidifies to obtain a fiber cross-section sample.

2. The preparation method according to claim 1, characterized in that: The predetermined mass is 1.5-2.4 g.

3. The preparation method according to any one of claims 1-2, characterized in that The hank is fixed by hanging one end of it and the hank is flattened by applying downward force to the other end of the hank.

4. The preparation method according to claim 3, characterized in that: The downward force is applied by hanging a weight at the other end of the hank.

5. The preparation method according to claim 4, characterized in that: The mass of the weight is 2.5-25g.

6. The preparation method according to claim 3, characterized in that: The glue comprises PVAL glue, and the drying temperature is 25-35°C.

7. A fiber cross-section sample obtained by the preparation method according to any one of claims 1 to 6.

8. The fiber cross-section sample according to claim 7, characterized in that: The fibers include elastic fibers, shaped fibers, or non-elastic non-shaped fibers.

9. A method for detecting a fiber cross section, characterized in that: The method comprises the following steps: slicing the fiber cross-section sample according to any one of claims 7 to 8 to obtain a sliced ​​sample, and observing the sliced ​​sample with a microscope.

10. The detection method according to claim 9, characterized in that: The slicing is achieved by using a Hastelloy slicer.

Images