FZ/T 01057.3-2007Test method for identification of textile fibres - Part 3: Microscopy (English PDF)

5.1 Instruments

5.1.1 Biological microscope, with a magnification of at least 100x.

5.1.2 Microscopic image analyzer. it shall comprise a microscope, a camera, a computer, an image acquisition card, dedicated analysis software, and a monitor. The microscope's objective and eyepiece shall provide a total magnification of at least 500x. A calibration scale for the instrument's magnification shall be included.

5.1.3 Hardy microtome. capable of cutting fiber sections with a thickness of 10 µm~30

µm.

5.1.4 Rotary microtome. features a concealed, silent ratchet mechanism, a crank-slider

assembly, and high-precision guide rails for the specimen block, enabling continuous sectioning of fibers with uniform thickness. The section thickness is adjustable within the range of 1 µm~40 µm.

5.2 Tools

5.2.1 Microscope slide. 76.2 mm × 24.5 mm × 2 mm.

5.2.2 Cover slip. 18 mm × 18 mm or 24 mm × 24 mm.

5.2.3 Dropper.

5.2.4 Blade.

5.2.5 Tweezers.

5.2.6 Black paper box.

5.3 Reagents

5.3.1 Anhydrous ethanol. analytically pure.

5.3.2 Ethanol (80% v/v). dilute 80 mL of absolute ethanol with water to a final volume of 100 mL.

5.3.3 Ethanol (90% by volume). dilute 90 mL of absolute ethanol with water to a final volume of 100 mL.

5.3.4 Anhydrous ethyl acetate. analytically pure.

5.3.5 Collodion. analytically pure.

5.3.6 Glycerol. analytically pure.

5.3.7 Liquid paraffin. analytically pure (refractive index between 1.43~1.53).

5.3.8 Sectioning paraffin.

7.1 Longitudinal view observation

Spread an appropriate number of fibers evenly onto a microscope slide (5.2.1). Using a dropper (5.2.3), add a drop of glycerol (5.3.6) or liquid paraffin (5.3.7), taking care to avoid trapping air bubbles. Place a coverslip (5.2.2). Position the slide on the stage of a biological microscope (5.1.1) or a microscopic image analyzer (5.1.2). Observe the morphology at a magnification of at least 100× and record the observations.

7.2 Cross-sectional observation

7.2.1 Prepare sections using a Harris microtome

7.2.1.1 Loosen the clamping screw 4 of the Hardy microtome (5.1.3). Pull out the locating pin 5.Rotate the holder base 6 to a position perpendicular to the groove 2 in the metal plate. Pull out the metal plate tab 1.See Figure A.1 in Appendix A for a schematic diagram of the Hardy microtome.

7.2.1.2 Comb a bundle of fiber specimens until neat and aligned. Clamp it tightly into the center of the slot of the Hardy microtome (5.1.3). First, use a sharp blade (5.2.4) to cut off the protruding fibers. Then, attach the upper spring mechanism and tighten the screw.

7.2.1.3 Slightly turn the scale screw 3 to cut off the exposed fiber.

7.2.1.4 Tighten screw 3 slightly. Using a dropper (5.2.3), apply a small drop of collodion (5.3.5). After it evaporates, carefully cut off the section using a blade (5.2.4) and set it aside.

NOTE. Alternatively, use other reagents or methods to fix the fiber sections for later use.

7.2.2 Prepare sections using a rotary microtome

7.2.2.1 Take a bundle of fibers and straighten it by hand-pulling. First, immerse the bundle in 80% ethanol (5.3.2) for 2 min, then remove and twist it between your fingers two or three times. Subsequently, treat the bundle sequentially in the same manner using

90% ethanol (5.3.3), absolute ethanol (5.3.1), a (1.1) mixture of absolute ethanol (5.3.1) and anhydrous ethyl acetate (5.3.4), and finally collodion (5.3.5). Remove the bundle, allow it to air-dry, and then proceed with paraffin (5.3.8) embedding and sectioning.

7.2.2.2 Mount the trimmed, embedded fiber wax block onto a wooden block.

7.2.2.3 Clamp one end of the wooden block into the specimen holder. Turn the wax block locking screw to clamp the wax block securely, ensuring it is parallel to the microtome knife. Adjust the position so that the wax block is close to the knife edge.

7.2.2.4 Adjust the setting on the rotary microtome (5.1.4) to the required section

thickness. A thickness of 6 µm~10 µm is generally most suitable for fiber sections. A schematic diagram of the rotary microtome is shown in Figure A.2 of Annex A.

7.2.2.5 Turn the handwheel clockwise to move the wood block up and down. Cut continuous ribbon-like sections. Gently remove the sections with tweezers (55.2.5) and set them aside.

7.2.3 Cross-sectional observation

Place the prepared fiber cross-section slices onto a microscope slide (5.2.1). Add a drop of liquid paraffin (5.3.7) - taking care to avoid trapping air bubbles - and cover with a coverslip (5.2.2). Place the slide on the stage of the microscopic image analyzer (5.1.2).

Observe and record the morphology at a magnification of at least 500x.

7.3 Identification of fiber types

By combining the longitudinal and cross-sectional morphologies observed in 7.1 and

7.2, and referring to the morphological characteristics and/or photomicrographs of the cross-sections and longitudinal views of various fibers, identify the basic fiber category.

Refer to Annex B for the morphological characteristics of the cross-sections and longitudinal views of various fibers. Refer to Annex C for examples of photomicrographs showing the cross-sectional and longitudinal morphologies of various fibers.