Textile Fiber Identification

The means of fiber identification can be broken down into five smaller groups or tests. They are burning, chemical, optical, staining, and density tests. Each test has its own advantages and disadvantages. Most are cheap and simple identification techniques, which is good. However, most fibers would need further analysis to be certain about the results. A burning test can help determine the class to which a fiber belongs by observing how the fiber burns. Observing how things smell and char when they are burnt are qualities than can help. However, have to be careful with burning tests in order not to over-generalize as to the type of fiber. The most important burning test pertains to flame resistance. Chemical tests are cheap and simple methods to find a number of elements, but the tests are not quantitative. Also, the number of elements that can be detected is limited. So for more accurate analysis, better and more expensive equipment is needed.

Optical tests are easily the simplest test available, and the use of a microscope allows the observer to see the fibers up close. This is valuable because certain fibers have particular shapes which can be identified when viewed under a microscope. However, not much more information can be attained about man-made fibers by microscopic examination of the longitudinal section alone. Viewing the cross-section helps greatly, but preparing cross-sectional samples takes great skill and time.

Staining tests can help to show changes in fiber structure from one process to the next. If the fiber structure is changed, the dyeing color will be different from batch to batch. A characteristic that can be obtained from dyeing is whether the fiber is hydrophobic or hydrophilic, because hydrophilic fibers are easier to dye because they absorb water. Staining can be used to group fibers into three groups: cellulosic, protein-based, or man-made fibers, but the process is not good on deep dyed samples and chemical finishes can interfere with the process.

Density tests offer a simple test of preparing a liquid in which the fibers will either sink or float, but porous fibers and fiber blends will skew the density results. Fiber identification by solubility is limited to synthetic fibers. Four basic solutions are used in the solubility tests. They are Acetone, Tetrahydrofuran, Methylene Chloride, and m-Cresol. As said above, there are five basic ways to fiber identification. They are burning, chemical, optical, staining, and density tests. They all have their own advantages and disadvantages and can help in certain cases for different fibers. Each test can lead to a hypothesis to help identify the fiber, but other tests are needed to confirm the hypothesis.