Properties
of Textile Fibers and Their
Testing Method
To become a textile fiber it should have some properties or characteristics. Because textile fibers must be spun into a yarn or made into a material by interlacing, or interlooping in an exceedingly sort of machines including weaving, knitting, braiding, felting, bonding, etc. So we are able to define textile fiber as, a fiber that has the power to be processed into yarn which may further be woven or knitted by certain interlacing methods is termed a textile fiber. ( Govt jobs in Pakistan ) ( Watch English dramas online )
In this article i'll discuss different properties/characteristics of textile fiber and within the time unit i've got given different testing methods of those properties
Physical Properties of Textile Fibers:
Length and length uniformity:
Length of staple fiber is one amongst the foremost important characteristics. Generally a extended average fiber length is to be preferred because it confers variety of benefits. Because its processing is relatively easy from short length fiber. Besides, more even yarns is produced from them because there are less fiber ends in an exceedingly given length of yarn and also a better strength yarn is produced from them for the identical level of twist.
Moisture regain:
The amount of moisture (water) present in an exceedingly textile sample is brought up either by its regain or its moisture content. These two terms are often confused with one another. Moisture regain is expressed because the percentage of water in an exceedingly sample compared to its oven dry weight, also brought up as its bone dry weight. Moisture content is expressed as a percentage of the overall weight of the sample. the quality test method ASTM D2495-07 is most ordinarily employed within the textile industry to live the regain and moisture content. The test could be a simple one and may be easily performed. A sample of fiber is collected and weighed, before being oven dried at 105°C until it maintains a continuing weight. The difference between the first mass before drying and therefore the oven dried mass is calculated as a percentage, and is denoted either as moisture content or moisture regain. Moisture regain and moisture content is measured using the subsequent equations.
W
R= ---------------- x 100 ------------------------------ (1)
D
W
C = ---------------- x 100 --------------------------------- (2)
D + W
R= ---------------- x 100 ------------------------------ (1)
D
W
C = ---------------- x 100 --------------------------------- (2)
D + W
Where,
R is the moisture regain
C is the moisture content
W is the weight of water
D is the oven dry weight
R is the moisture regain
C is the moisture content
W is the weight of water
D is the oven dry weight
Trash content:
The presence of undesirable material within the fiber is taken into account to be trash. Other synonyms include contamination and nonlint matter. it's comprised of fragments of leaves, stalks, grasses, seeds, and dust. It also includes feathers; pieces of plastic, rugs, and cloths; foreign fibrous material aside from the specified fiber (like polyester or jute in cotton); and immature fibers. The immature fibers of the identical desired fiber are considered to be trash as they're not wanted within the final product. A Shirley analyzer is employed to see trash content within the fibrous tuft. It comprises a pair of rollers for gripped feeding into a sawtooth beater, rotating at a high surface speed.
Cross-sectional shape of the fiber:
Shape affects the physical and mechanical properties of textile fiber. There are many properties which are changed by the form of the fiber’s cross section, like flexural rigidity, fabric softness, drape, crispness, and stiffness. Different natural fibers have differing types of shapes, while the form of artificial fibers depends upon the form of the spinneret from which they're extruded, as shown in Figure. Like silk it's a triangular cross section. Cotton fibers are kidney shaped. Wool fibers are round or oval in shape.
Fiber color:
The color of the fiber is a very important aspect in relation to aesthetic sense and dye shade. Every fiber type has its particular color regarding its natural or synthetic origin. In natural fibers, cotton is found as white to yellowish in color, wool fiber has whitish to blackish color grades, silk fiber is found during a lustrous white color, and jute fiber is brown. Regenerated rayon fibers are transparent in color unless dulled by pigments. In synthetic fibers, acrylic ones are white to off-white, nylon ones are off-white, polyester ones are white, para-aramid ones are dull yellowish, and carbon ones are black. Some fibers may be decolored to introduce new colors by the dying process, while other fibers have a permanent color which can’t be removed, as within the case of Kevlar and carbon fibers.
Fiber fineness:
Fineness is one in all the most important aspects of fiber characteristics and explains cross-sectional thickness. A fine fiber may be wont to spin fine yarns. because the linear density of yarn decreases, the quantity of fibers also decreases by yarn diameter. The presence or absence of one fiber shows longitudinal unevenness and variation in diameter. The decrease of fiber diameter will increase the quantity of fibers during a cross section of yarn and hence better yarn evenness may be achieved.
Fiber fineness has great influence on the properties of yarn and fabric. The evenness of the yarn is improved by the utilization of fine fibers. additionally, fine fibers need less twist and have less stiffness than coarser fibers. the rise in fiber surface thanks to a decrease in fiber diameter contributes to a cohesion of fibers to realize the identical strength with less twist than coarser fibers. These characteristics contribute to the hand feel of the products developed from them.
Fiber crimp:
The waviness during a fiber is understood as crimp. it's measured because the number of crimps or waves per unit length or the share increase within the extent of the fiber on removal of the crimp. Crimps also govern the capacity of fibers to cohere under light pressure. The bi-component structure of wool increases the crimp in it. Cotton incorporates a low crimp. Crimp allows the scattering of sunshine thanks to its wavy structure and provides a dull appearance on developed products. Synthetic fibers are lustrous in structure, which might be reduced by the introduction of crimps in them. Crimps increase the thickness and enhance the bulky aspect of products.
Mechanical Properties of Textile Fiber
Fiber strength:
Strength of any material comes from the load it supports at break and is thus a measure of its limiting load bearing capacity. Normally strength of a textile fiber is measured in tension when the fiber is loaded along its long axis and is designated as durability.
The strength and elongation of a cotton fiber may be measured by one fiber or by the bundle method. The bundle fiber strength may be measured using an ASTM standard test procedure that employs a nerve tissue tensile testing machine. These machines are commercially available in pendulum and machine mechanisms. A fiber sample is conditioned as per the quality conditioning procedure.
Tenacity:
Tenacity is that the measure of the breaking strength of a textile fiber. it's also defined as ultimate breaking strength and is that the maximum force a fiber can bear without breakage. The tenacity value for individual fibers is that the value of load applied at breakage. the precise stress is that the ratio of load to linear density and is measured in units of g/denier, cN/tex, and MPa.
Blending is that the easiest method to get synergistic effects of two different materials. within the textile industry the blending of a fiber may be a common practice to get the specified functional and aesthetic properties. Blends may be identified either qualitatively or quantitatively. Furthermore, the testing methods for the identification of fibers during a blend may be technical or nontechnical.
The nontechnical tests include the sensation test or the burning test; these tests are for qualitative assessment.
Maturity ratio:
The maturity of the cotton fiber is analyzed using the ASTM standard test procedure by employing polarized light or the hydroxide swelling technique. an answer of 18% concentration of hydroxide is employed to swell the cotton fibers by soaking them. The fibers are then laid parallel on the sheet glass and covered with glass and viewed at a magnification of 400× to differentiate between immature and mature fibers. The mature fibers swell to become almost round in cross-sectional shape. This method isn't considered acceptable for commercial testing thanks to the poor precision of the results between different laboratories.
Chemical composition:
The chemical composition of fibers depends on their origin. Natural fibers obtained from plants are made from cellulosic structures like cotton, jute, and hemp fibers. The fibers obtained from animals are composed of amino acids like wool and silk. Regenerated fibers have the identical chemical composition as those obtained from their parent origin, like rayon which is cellulosic in nature. The chemical composition of synthetic fibers is predicated on the character of their raw materials and also the chemical reactions that occurred.
Reference:
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