Essential properties of textile fibres
There are an enormous amount of fibres available but among them, few are applicable as textile fibre. That represents that the fibres need to have some specific characteristics and properties within the range of certain parameters to be considered as a textile fibre. These properties and characteristics are discussed below.
Essential properties:
1. Fibre Length
2. Fibre Strength
3. Flexibility
4. Uniformity
5. Cohesiveness
(Link of desirable properties)
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| Essential fibre properties |
Fibre Length
The ratio of Fibre Length to Width: Fibrous materials that are made into twisted yarn must have sufficient length, while the width of the fibre (the cross-sectional diameter) must be much smaller than the overall length of the fibre, the nominal diameter of the fibre should be 1/100 of the length of the fibre.
The majority of natural fibres are stapled fibres, while manmade fibres generally come in filament or staple form, depending on how they are processed before yarn formation. As far as spinning is concerned, fibre length is the most important parameter determining the suitability of fibre to be a textile fibre.
Ideally, the fibre should be at least 5 mm long. In the case of continuous yarns made from individual fibres, their length-to-width ratio should be very high. Until this is achieved, it will be impossible to spin a yarn that can hold together the fibres. This is nothing but the length-to-breadth ratio.
In general, textile fibres with the best properties will have a length-to-width ratio (L/W) of more than 100:1, almost all popular fibres have an L/W ratio greater than 1000:1, and length determines the material's processing potential. Oftentimes, this is one of the most important factors when pricing natural fibres, with the length being determined by the ring and air-jet spun cotton yarns.
Longer fibres can be processed more easily and can be used to make finer and stronger yarns, but shorter fibres can be bulkier and can reduce spinning yield since fibres are lost during spinning. For natural fibres, every supply has a distribution of lengths ranging from very long to very short, and there are objective methods to characterize the average length and variation and uniformity within samples.
For synthetic materials, staple length can be precisely controlled through filament cutting and can be optimized to ensure good performance on existing equipment.
- Fibre Length to Width Ratios of some Natural fibres:
For Cotton fibre it is 1400, for Silk, it is 3,30,000(Highest due to filament structure) for flax and Wool it is 1700 and 8000 respectively.
A high ratio of length to breadth is equally important when it comes to manmade fibres.
The diameter in which the fibres are spun can be tailored to meet the need of the end-user; these fibres can have a wide range of diameters, but in general, they share the same characteristics as natural fibres.
It is typical for viscose and cellulose acetate filaments to have diameters between 10 and 30 *m, similar to those of natural fibres. Manmade fibres are generally used as continuous filament yarns. In the case of cutting such filaments into staple fibres, the staple length is mostly greater than 25.4 mm (one inch). For a fibre to be useful as a textile fibre, a high length-to-diameter ratio is a requirement that applies equally to both natural and synthetic fibres; the staple length of such fibre is the key parameter for deriving its characteristics.
A longer fibre average offers several advantages. In addition, longer fibres have a greater process-ability than short fibres and can yield more even yarns because there are fewer ends per given length, and they can also yield a stronger yarn for the same twist as shorter fibres.
Fibre Strength
Fibre or yarn made should have enough strength so that it can be processed into a fabric or other textile article. After fabrication, the textile must possess sufficient strength to last during its intended use.
It is believed that a fibre of at least 5 grams per denier strength is necessary for most textile applications, although fibres as low as 1.0 grams per denier strength have been found suitable for some applications.
The strength of any material is the amount it can carry before breaking. This is the actual measure of its limiting load-bearing capacity.
Consequently, tenacity can be calculated as breaking load/mass per unit length, typically strength of the textile fibre is measured in tension when the fibre is loaded along its length axis and is referred to as its tensile strength.
The tensile strength of the textile fibre is defined by the maximum tensile stress in force per unit area or per unit linear density, at the moment of breakage or rupture, expressed in grams per denier or grams per Tex units.
The strength of any material is determined by the load it can support at break and so is a measure of its limiting load-bearing capacity. It is expressed in grams per Tex (grex) or grams per denier (gpd).
Fibre tenacity of Natural fibres in Grams per Denier (gpd) for cotton is in the range of 3.0 - 4.9; for Jute fibre, it is 3.0 - 5.8; For Flax fibre, 2.6 - 7.7; For Ramie 5.5; For Silk 2.4 - 5.1; For Wool fibres 1.1 - 1.7; and for Hemp fibres, it is 5.8 - 6.8.
Flexibility
As long as the fibres are sufficiently pliable, they can be wound around each other in the process of mechanical spinning.
On the other hand, if the fibre is stiffer and winter, then it isn't suitable for the textile application, examples of such fibres are glass and metallic fibres. Fibres must be sufficiently strong to bend repeatedly without deteriorating significantly.
Creating yarns and fabrics from fibres would be impossible without adequate flexibility since bending and flexing the individual fibres is a necessary step in this process. In addition, individual fibres of textile will be bent and flexed in considerable amounts during final applications.
Uniformity
Fibres that can be twisted into yarn or fabric must have fairly uniform dimensions and properties, Otherwise, the actual formation of the yarn will be impossible, or the resulting yarn might be brittle, rough, irregular in size and shape and unsuitable for textiles.
In natural fibres, sorting and grading ensure fibre uniformity, while in synthetic fibres, "tailoring" can be done to produce a uniform length of fibre to ensure a proper degree of fibre uniformity.
Uniformity refers to the length and fineness of the fibres that are spun into yarn. Materials used to make yarn should be similar in length and width, as this ensures a good quality yarn both in spinning quality and inflexibility.
In general, these fibres need to be possessed equally in terms of thickness and length. (Cotton and wool fibres are kinds of assumptions for this) As a result of the natural variations that occur during the different stages of fibre growth, any specific quality, grade or lot of natural fibre may vary considerably in length and diameter.
In contrast, artificial staple fibre is more uniform since it can be cut exactly to length during manufacturing (during spinning) and the diameter can be controlled within a close tolerance limit during its manufacture.
The process parameters and manufacturing conditions of manmade fibres can easily be controlled, while the production conditions of natural fibres are difficult to control as the conditions surrounding cotton growth are so variable.
As such, it is crucial to mix a large number of batches of natural fibres to eliminate the natural variations in the fibres that would otherwise occur while manufacturing good quality yarn and fabrics from them.
Cohesiveness
Fibre must be cohesive to be spun into a yarn, The cohesiveness may be due to the individual fibre s contours or the surface of the fibre, Besides, long-filament fibres can be twisted together to lend stability to the yarn without true cohesion between the fibres.
Sometimes, the term "spinning quality" is used to describe the overall attractiveness of the fibres to one another. In yarn spinning, this is the process in which the individual fibres attach when they are twisted together, often because of the high level of frictional resistance offered by the surfaces of the fibres, For example, wool fibres have sharp edges that easily grab onto one another during mechanical spinning.
Cotton fibres also possess roughness or irregularity on their surfaces as well as twists induced by natural processes (a.k.a. convolutions). The rough surface and the convolutions of cotton fibres help them adhere together and interlock when spun into yarns. Therefore, in the crimping process, synthetic fibres(Especially short fibres) have a higher level of interfiber cohesion, so the cohesiveness of textile fibres determines better fabric quality.
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| Cotton fibres |
- Which properties are essential for any fibre to be a textile fibre?
- Describe fibre length in brief.
- Describe fibre strength in brief.
- Describe the flexibility of fibre in brief.
- Describe the uniformity of fibre in brief.
- Describe fibre Cohesiveness in brief.
References
Essential and desirable Properties of Textile Fibres. (2017, September 2). Online Textile Academy. https://www.onlinetextileacademy.com/essential-and-desirable-properties-of-textile-fibres-characteristics-of-good-textile-fibre/
Rony, J. (2022, January 24). Primary and secondary properties of textile fibres. Fashion2Apparel. https://fashion2apparel.com/primary-and-secondary-properties-of-textile-fibres/
Sayed, A. (n.d.). General properties of textile fibre. Blogspot.com. from https://textileapex.blogspot.com/2015/11/properties-of-textile-fibre.html
Sinclair, R. (2015). Understanding textile fibres and their properties. In Rose Sinclair (Ed.), Textiles and Fashion (pp. 3–27). Elsevier.
Textile fibres and their characteristics. (n.d.). Jamesdunloptextiles.com. from https://www.jamesdunloptextiles.com/journal/tips-how-to/textile-fibres
What are the primary properties of textile fibers? – YnFx. (n.d.). Yarnsandfibers.com. from https://www.yarnsandfibers.com/textile-resources/fiber-properties/primary-and-secondary-properties-of-textile-fibers/primary-properties/primary-properties/
Further, read,
Part 1 Textile fibre's essential properties
Part 2 Textile fibre's desirable properties
