Various methods are used in the textile industry to understand which fibers or fibers are produced from a textile product. In some cases, it is only possible to perform a test to determine the fiber from which the product is woven. However, the decision is generally healthier based on the results of several different tests. Such tests are called qualitative fiber analyzes. It is possible to group the tests in five groups:

• Combustion tests

By holding the fiber to a small flame, it is determined whether the fiber is vegetable, animal or synthetic from its burning shape, smell during combustion, and post-combustion residues.

• Microscope tests

Microscope tests give more accurate results in measuring the length and diameter of fibers, in defining, classifying fibers, determining the shape and degree of damage caused by fungi, bacteria and other pests and in determining fiber structures.

• Dry distillation

In these tests, essentially, the pH of the gases released by dry distillation of the fiber is determined.

• Painting tests

The dyeing properties of the fibers are different. Therefore, during the tests, the fibers are dyed with special test dyes in different colors and shades. The results are evaluated and the type of fiber analyzed is determined. These tests are very easy and frequently performed.

• Tests with chemical solvents

The fibers are distinguished according to their solubility in chemical substances and their solubility. If the chemical that dissolves the test sample is identified, the fiber is also identified. For various fibers, the chemical substances they dissolve are predetermined.

Fiber analysis and qualitative evaluation of textile products are carried out in authorized laboratories. Laboratories take into consideration the standards published by local and foreign organizations during these studies. Fiber analysis and qualitative evaluation activities are based on the following standards:

• TS 4739 Methods for the recognition of textile fibers

This standard specifies methods for physical, chemical and microscopic identification of fibers used in weaving.