Method Of Exploring Cross Section Of Yarn

< p > < < a href= > http://www.91se91.com/news/index_c.asp > > textile > /a > composition analysis, we will encounter the situation that the fiber type can not be accurately judged according to the longitudinal section of the fiber. At that time, we need to cross section the yarn, and judge the type of fiber by observing the cross-sectional shape of the fiber dimension.

At present, the widely used collodion embedded fiber technology in China is simple and easy to operate. It is a shortcut to observe the shape of a href= "http://www.91se91.com/news/index_c.asp" > fiber cross section < /a > shape. However, there is a problem of extrusion deformation between the fibers and fibers in the cross-sectional images obtained by Hauser slice method, which is not conducive to the accurate expression of fiber cross section characteristic parameters in the process of textile detection.

In this paper, Hauser slice method and resin embedding method were used to separate and separate the yarn.

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< p > < strong > 1 test part < /strong > < /p >

< p > < strong > 1.1 test material < /strong > < /p >

< p > methyl methacrylate (chemical pure CP, China Pharmaceutical Group Chemical Reagent Co., Ltd.), butyl methacrylate (chemical pure CP, China Pharmaceutical Group Chemical Reagent Co., Ltd.), polymethyl methacrylate (chemical pure CP, National Medicine Group Chemical Reagent Co., Ltd.), glycerin (analytical pure, Yixing second chemical reagent factory), collodion liquid (chemical pure, Shanghai bronzing material factory), peroxide two benzoyl (chemical pure, Beijing chemical reagent company).

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< p > < strong > 1.2 test instrument < /strong > < /p >.

< p > haste slicer, DGG-9030A type electrothermal constant temperature air drying oven, S21-2 constant temperature magnetic stirrer, JT302N electronic analytical balance, DZG-6020 type vacuum drying box, Leica RM 2126RT type hand slicing machine, YG002C type fiber detection system.

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< p > < strong > 1.3 test method < /strong > < /p >

< p > < strong > 1.3.1 Haversian slice [3-4] < /strong > /p >

With a hand pull method, straighten it up and wrap a yarn in < p a > href= > http://www.91se91.com/news/index_c.asp > > wool > /a > add into the groove of haste's slicer. The number of filled wool should be slightly shifted when the light is pulled out of the wool. Use the sharp single blade to cut out the fibers outside the positive and negative sides of the Harris slicer, turn the screw holder back to the original position, rotate the precision screw half cell or a lattice, make the fiber bundle slightly extend on the surface of the metal plate, and then spread a thin layer of collodion on the exposed fiber. After the dried cotton wool is dried, use the sharp single blade to slit along the metal plate surface at a angle of about 10 degrees. < p > a bundle of wool fibers.

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< p > in the process of slicing, the force should be uniform. The angle between the blade and the metal plate should be about 10 degrees, and the angle must be kept unchanged. Only in this way can we get a thin slice with uniform thickness and good quality.

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< p > < strong > 1.3.2 resin embedding method < /strong > /p >

< p > < strong > (1) the preparation of embedding agent < /strong > < /p >

< p > mixing methyl methacrylate (MMA) and n-butyl methacrylate (BMA) at a ratio of 3 to 2.6 (volume ratio), adding a small amount of polymethyl methacrylate (PMMA), stirring on a constant temperature magnetic stirrer for 5 hours, so that PMMA is fully dissolved in MMA/BMA mixed monomers.

Adding 1% benzoyl peroxide (BPO) to the monomer solution and adding the two benzoyl peroxide to the mixture for about half an hour, the required embedding agent can be prepared.

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< p > < strong > (2) yarn embedding is less than /strong > /p >

< p > the ends of the yarn are fixed by sewing thread. The prepared samples are put into a sealed polypropylene pipe. The embedding agent is poured into the polypropylene pipe and vacuum is put into the vacuum dryer, and then the other end of the polypropylene pipe is sealed.

After sealing, the yarn can be kept parallel and straight in the plastic rigid tube by pulling the sewing thread.

The samples were put into the oven and polymerized 8h at 65 degrees Celsius.

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< p > oven temperature plays a decisive role in the success of embedded samples.

When the oven temperature is high, the polymerization reaction is faster, but the temperature is too high to cause explosive polymerization, resulting in the failure of the experiment. When the oven temperature is low, the polymerization reaction time is less than /p.

< p > longer, but the success rate is high.

Therefore, the test temperature of this experiment is 65 degrees. The resin block obtained by polymerizing 8h at this temperature is moderate and soft, and the success rate is high.

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< p > < strong > (3) slice production < /strong > < /p >.

< p > remove the polypropylene tube and remove the fibrous embedded body, and slice it on the stage of the Leica RM2126RT type hand slicing machine.

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< p > the slices made of two methods will be put on the glass slide containing glycerin, and the cover glass will be covered and the cross section of the yarn will be observed by YG002C fiber detection system.

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< p > < strong > 2 image analysis of yarn cross section < /strong > < /p >

< p > cross section images of the yarn, the fibers in the Harris sliced method are closely distributed, extruded, bonded and deformed seriously, which is not conducive to the identification of fiber types. The resin bonded cotton fiber and viscose cross section boundary is clear, the dispersion is high, the characteristics are obvious and easy to distinguish.

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< p > it can be seen that, whether natural or chemical fibers, the cross-sectional section of yarn obtained by resin embedding method has high dispersion of fibers, less extrusion of fibers, clear fiber boundaries, obvious cross sectional characteristics of fibers, easy identification of fibers, and better cross-sectional images than those obtained by Harris slicing method.

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< p > < strong > 3 conclusion < /strong > < /p >

< p > (1) the quality of yarn slices obtained from haste's slice method is very much related to the proficiency of the operator. In contrast, the embedding process of yarn embedding by resin embedding method has low requirement for the proficiency of the operator, and has strong operability, which makes the reproducibility and stability of the cross-sectional section of the yarn greatly improved.

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< p > (2) the image quality of the yarn cross section obtained by Harris slice method is poor, and the yarn is squeezed in the process of slicing, resulting in a lot of adhesion between fibers in the yarn, and the deformation of the fiber cross section and the boundary is not clear.

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< p > (3) resin embedding method can effectively reduce the extrusion of yarn in the process of slicing, and the cross-sectional section of the yarn can be clearly discernible, which effectively reduces the systematic error value of the quantitative index such as fiber diameter caused by the extrusion of fibers in the sample preparation process, which is conducive to improving the efficiency and quality of the microscope detection method.

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