Last updated on September 3rd, 2023 at 12:45 am
For our daily purposes, we wear different types of dresses. For the morning walk, we like to wear tracksuits. For swimming, we’ve to wear swimsuits. Also for heavy works we need to wear work-wears. So the physical properties of our clothing are an important factor. To have good physical properties, tear and tensile for woven and bursting strength for knit fabric need to be good enough.
For good physical properties of the fabric, yarn strength is very important and is the main factor. And now we will discuss the factors that affect yarn strength.
Factors that Affect Yarn Strength are as follows:
Longer staple cotton gives higher strength and this is true even in the case of synthetic staple fibre such as nylon and terylene. Low twist factors will give stronger yarn in case of longest fibre.
Fine fibre gives strong yarn compared to coarse fibres which are spun into the same given count of yarn. This is due to the fact that more number fibres in the cross-section and also increased internal friction provided by the higher number of fibres in the cross-section of the yarn. Hence the result is higher yarn strength.
Logically speaking fine fibre results in providing strong yarn but the paradoxical statement of Dr. Balls states that weak and fine fibres produce stronger yarn. In the case of cotton fibre, fibres will have a longer length and hence more fine fibre can be accumulated in the same cross-section and such as the strength of the individual fibre is of no significance. Therefore yarn strength is the strength of a group of fibres.
For a single spun yarn, increases in twist gives a higher strength up to a certain limit and any twist than this optimum will decrease the strength. The amount of twist for maximum strength depends on the twist angle and for any given fibre the twist angle for maximum strength remains constant over a range of yarns.
Evenness in the yarn or uniformity in the spun yarn influences the yarn strength. Greater uniformity shows an increase in strength and uneven yarn will show a reduction in strength. An investigation has proved that there is a very close relationship between yarn strength and yarn evenness.
Fibre Length Variation and Distribution
Fibre length variation and distribution will also cause the variation. When spinning cotton, containing more short fibres, the resultant yarn will have lower strength. In the presence of short fibres, the resultant yarn will have lower strength. The presence of short fibres influences, to a very great extent, the yarn strength. Therefore limitations have to be introduced while mixing such fibres.
The man-made fibres, especially synthetic fibres, are treated with several chemicals to change the processing character. The type and amount of chemicals will have a definite influence on the strength properties of yarn and also on the processing characteristics of staple fibres.
There are many other variables that also influence the strength property of yarn. The chemical treatment given to the yarn after spinning such as sizing etc will either increase the strength or decrease the strength. Some of the chemicals tender the material and there will be a loss in strength. Apart from this chemical treatment, the position of individual fibres in the characteristic yarn will also affect the tensile property since the building up of a spun yarn is a resultant factor of drafting and twisting. The twist is a dynamic property. The twist in the yarn is stabilized only when the dynamic balance also influences the tensile property.
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