Determine the categories, and then separate the varieties and then further verified. If using combustion method to identify towel natural and man made fibres, used microscopes to identify various towel towel plant fibers and animal fibers. For fibres, using chlorine and nitrogen analysis distinguishes does not contain chlorine, do not contain nitrogen, chlorine does not contain nitrogen, chlorine-containing nitrogen, nitrogen-chlorine-containing five situations, and chemical fiber melting point, density, double refraction, differences in solubility, one distinguishes various types of synthetic fiber and recycled fiber. For some special fibers, can be identified by infrared absorption spectra.
In differentiating towels when mixing fibers and blended yarn, can be observed with a microscope, and confirmed that contains some fiber, then use other methods as appropriate identification. After dyeing or finishing of fibers, it is usually dyed peeling or other appropriate pretreatment, may well ensure identification is accurate and reliable. BI-component fiber or fiber, it is usually observed with a microscope, and then individually identified by dissolution and infrared absorption spectrometry.