What are the primary properties of textile fibers?
The textile fibers are either procured from nature in the fibrous form or are manufactured through a series of chemical reactions. A large variety of fabrics are available in the market manufactured for various purposes. But how do we determine which fabric is suitable for the article we intend to develop. It is through the primary and secondary properties that define a fiber and in turn the fabric.
For example, if we wish to develop a jacket for firefighters, the fabric should be equipped with certain properties such as high tensile strength, thermal resistance, etc. Thus, every fiber must possess certain prerequisite characteristics to qualify as a textile material. The fiber properties are classified as primary and secondary properties.
Primary or essential properties are those properties that a textile fiber must possess to qualify as a textile material. The essential or primary properties of a textile fiber include:
1. High Length to Width Ratio:
For any fiber to be spun made to yarn and then into fabrics is that their lengths must be more than their widths. The minimum length to width to ratio is 100:1.
The length of fibers is also a basis for classifying them into two groups: staple and filament fibers. Staple fibers are short length fibers and generally obtained from the natural sources except for silk while filament fibers are long length fibers.
In addition, the width of fiber referees to the diameter. This is measured in microns and determines the fineness of fibers. A point to note here is that the diameter of the synthetic fiber depends on the size of the spinneret hole.
Also, finer fibers are softer, more pliable, and have better drapability.
Tenacity is also referred to as the strength of the textile fiber. It is the force required to break the fiber. The strength is basically classified into three types on the basis of force direction of force: 1. Tensile strength (Uniaxial Force) 2. Tear strength (Biaxial Force) 3. Bursting strength (Multi-axial Force).
Each fiber must possess a certain amount of strength to be able to bear the mechanical and chemical processing that it undergoes during the manufacturing processes. When determining the tenacity of fiber, it helps us to understand how the fiber will bear the force both in dry and wet conditions. For example, cotton is stronger when wet as compared to wool which is weak in a wet state.
Flexibility is regarded as how much flexible or pliable a fiber is in order for it to be made into yarns and thereafter into the fabric for easy movement. Certain products require a fabric that is flexible; one such example is automobile seat belts.
Let’s understand this property with an example: we have certain fibers that are composed of wood but these do not find application in the industrial textiles due to lack of flexibility. While materials made from glass or metallic fibers possess low elasticity and are stiffer, ruling them out to be used in the apparel sector.
And so, this property helps us to identify fibers intended for the end-use of a product.
4. Spinning Quality or Cohesiveness:
Cohesiveness is the property of the fibers to adhere to each other during the yarn manufacturing process. The process of spinning makes the fiber surface resistant to friction and it is this lack of mobility that enables the fiber to stick together when being spun into yarns.
There are some inherent irregularities in the longitudinal or cross-section of the natural fibers which permit them to hold to each other during the fiber arrangement. Wool, for instance, has an inherent crimp and scales on its surface that imparts a high degree of cohesiveness. And in the case of synthetic fibers, it is the long length of fibers that brings cohesiveness. Also, smooth filament fibers undergo texturing techniques that bring a certain amount of curl, crimp or loop contributing to cohesiveness.
Uniformity is an important property of fibers because it is even yarns that make fabric uniform in appearance and consistent performance. Uniformity is also associated with strength and other properties such as uniformity in length and thickness.
The natural fibers are since procured from natural sources such as sheep hair, silkworm, seed hair, etc and so are subjected to differ from each other in length, thickness, or quality. For instance, wool fibers sheared from the sheep has various grades depending on the area from which it is taken for example fibers on the lower leg and underbelly are prone to contamination due to the vegetable matter that entangles in them during grazing while the best quality is achieved shoulder, sides, and back of sheep.
However, synthetic fibers are more uniform since the yarns can be cut into the desired length and the diameter can be determined by the holes of the spinneret, they pass through during chemical spinning processes.