AATCC 20:2007 pdf download.Fiber Analysis: Qualitative
8.1 In many cases the identity of an un- known fiber can be established without pretreatment.
8.2 When the presence of starch, wax, oil or other coating obscures the appear- ance of the fiber, try heating in warm to hot distilled water to remove the foreign matter. If this fails, try extracting with organic solvents, 0.5% hydrochloric acid or 0.5% sodium hydroxide. Some fibers such as nylon are damaged by acid and some such as azlon, silk and wool, are damaged by caustic treatment (see 9.7).
8.3 To separate vegetable fiber bun- dles, treat with 0.5% sodium hydroxide solution, rinse well with water and dry.
8.4 To strip dye from colored fibers, especially the cellulosic fibers, heat for 30 min at 50°C with hydrosulfite caustic solution (see 6.2.1).
9. Procedure
9.1 The identification of fibers is usu- ally carried out by subjecting specimens to a variety of selected tests until enough information is obtained to make a satis- factory judgment as to the generic class or specific type. The selection of tests and order in which they are performed can change depending on the knowledge already available and results of the pre- liminary tests.
9.2 Visual and Microscopical Exami- nation.
9.2.1 Examine the sample of material submitted for identification. Note form (loose fibers, yarn, fabric, etc.), color, fi- ber length and fineness, uniformity of appearance and probable end-use. If the sample is a fabric, separate out yarns by unraveling or cutting. If the fabric is woven, separate warp and filling yarns. If yarns differ in color, luster, size or other apparent ways, make a physical separation of these yarns for separate identification.
9.2.2 The fibers may be identified using either light or scanning electron micros- copy. If using transmitted light micros- copy, place a small quantity of the fibers on a glass slide, tease fibers apart, mount with a drop of mineral oil or other immer- sion fluid, cover with a cover slip and ex- amine under the microscope. AATCC 20 pdf download.