Textile Physics

In Textile Technology, physics plays a large part. The study of the structure & physical properties of fibers, yarns & fabrics forms the unified subject that is legitimately called textile physics. It is an essential part of education of any textile technologist.
Requirements for fiber formation: The requirements for fiber formation are given below,
1.     Molecules chains are long.
2.     A more or less parallel arrangement of the molecules.
3.     Lateral forces to held the molecules together and give cohesion to the structure.
4.     Some measure of freedom of molecular movement in order to give the necessary extensibility to the fiber and some openness to give room for moisture absorption and uptake of dyes.
Morphology of fiber structure: Morphology refers to form and structure of a substance. There are many theoretical approaches of fiber structure. These are,
1.     Fringed micelle.
2.     Modified fringed micelle.
3.     Extended china.
4.     Fringed fibril.
5.     Para crystalline.
6.     Three phase polymer single crystal.
Fringed micelle:
The micelle was assumed to be smallest structural aggregated of micro molecules. The discrete brick like submicroscopic particles are oriented with respect to the axis of the fiber & account for the crystalline of the fiber. The remaining matter is just amorphous matter separating the micelles. Since the polymer molecules are much longer than the molecules. They can run through successive crystalline & regions give fringed micelle.
fringed-micelle
Modified fringed micelle:
It was found that polymers used in fiber could be crystallized form dilute solution so as to give single crystals. In these lamellar crystals, the chain molecules are folded back & forth as illustrated in figure. Similar folding may occur in fibers & this had led to the suggestion of modified fringed micelle structure in which there is a mixture of fringing & folding at the end of each micelle as indicates in figure.
modified-fringed-micelle
Fringed fibril concept:
The electro microscope observation of micro fibrils in cotton & other natural cellulose fibers, in wool & in some form of rayon’s was reason for the introduction of an alternative to the fringed micelle structure since the fibril’s & the micelles were thought to have the same thickness, the two forms were incompatible. Therefore proposed a fringed fibril structure as are shown in the figure. This combines (a) a fibriller form & (b) the idea inherent in the fringed micelle structure of definite crystalline & non crystalline regions with chain molecules running continuously through each type of region.
fringed-fibril-concept

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