Types of Textured Yarns
The yarns produced by this method can be divided into three:
- Stretch yarns
- Modified yarns
- Bulk yarn
Stretch Yarns - These are crimped yarns that are known for their great extensibility, favourable recovery, and bulk.
They can be produced by either false-twist or Edge crimping processes with only one heating zone. Their application areas are where extensibility and comeback from the stretch are required.
Modified stretch yarn - These textured yarns are like an intermediate between stretch and bulky yarns.
These are produced by additional heat treatment through a second heating zone to the stretch yarn during false-twist or Edge crimping methods. By doing this, the yarn structure, yarn bulk, and stretch are stabilised.
They are used where reduced extensibility and better appearance are required.
Bulk yarns - The application for these yarns is where the bulk and fulness of the yarns are a priority.
The yarns have moderate stretch but high bulk.
They are manufactured by air texturing, knit-de-knit process, her crimping, stuffer box, and other crimp texturing methods. Application areas include carpets, upholstery, and apparel required for warmth and comfort.
As, synthetic fibres are heat sensitive, even simple mechanical deformation or heat treatment can help in providing crimp structure.
Textured yarns can be achieved by any of the following methods:
- False-twist
- Edge crimping
- Stuffer box process
- Gear crimping
- Knit-de-knit
- Air texturing
1. False-twist: This is the most widely used technique. Here the filament yarn is first twisted, then heat-settled and at last I twisted to produce the textured yarn. The machines used for false twist texturing are- (1) machines with a single heating zone, (2) machines with a double heating zone, and (3) machines that can draw and texturize the partially oriented yarns in a single continuous process. The yarns produced by this method are used in the garments industry.
2. Edge crimping: This process is used for the production of non-torque textured yarn. The process is carried out by heating the yarns and then drawing them on a blunt knife as they cool down. This yarn made from this method is mainly used in the hosiery industry.
3. Stuffer box: In this process, the filament yarns are overfed into a confined area having small heated chambers called a stuffer box. The yarns are compressed to obtain bulky yarns. They are adopted for upholstery.
4. Gear crimping: The process involves transferring a heated yarn through pair of rotating gears which are cold. A mechanical distortion takes place due to the compression by the gear teeth due to the varied pitch of gear teeth. Their main application fields are upholstery and the hosiery industry. This method is normally used in combination with other texturing techniques.
5. Knit-de-knit: The method consists of first knitting the filament yarn on a circular knitting machine, heat-setting, and then debilitating. Later, after de-knitting, the yarn distorts according to the shape of the loops and the initial thickness of the knitted fabric. The yarn made from this process is also used in hosiery.
6. Air-texturing: Also known as the ‘Taslan Process', consists of blowing a jet of air into a twisted or untwisted continuous filament yarn. The yarn is fed at a higher rate than the delivery to the take-up bobbin. The overfeed and jet action causes a formation of random loops in the filaments such that the yarn contracts and bulk increases while processing. The air-textured yarn resembles nearly a spun yarn. The yarns are versatile in all textile-related industries.
Questions -
- What are the types of yarn texturising?
- Which are the types of methods used to texturise the manmade yarn?
References
Davis, R. (2020, July 23). Recent innovations for staple & man-made fiber spinning. Textileworld.com. https://www.textileworld.com/textile-world/features/2020/07/recent-innovations-for-staple-man-made-fiber-spinning/
man-made fibre - Processing and fabrication. (n.d.). In Encyclopedia Britannica.
Sayed, A. (n.d.). Processing of Man-made fibres and Blends on Rotor Spinning. Blogspot.com. from https://textileapex.blogspot.com/2015/01/man-made-fibres-processing-blends-rotor-spinning.html
Shishir, M. M. H. (n.d.). Man made fiber spinning. Slideshare.net. from https://www.slideshare.net/sheshir/man-made-fiber-spinning
Textile School. (2011, June 20). Manufacturing of manmade fibers. Textile School. https://www.textileschool.com/443/manufacturing-of-manmade-fibers/
Types of spinning (man-made fibers). (n.d.). Blogspot.com. from http://textileengineerr.blogspot.com/2010/10/types-of-spinning-man-made-fibers.html
Further reading,
Part 1 Introduction to Manmade spinning
Part 2 Manmade Spinning Processes - Dry-jet-wet spinning
Part 3 Dry, Wet, and Melt spinning Processes
Part 4 Drawing and texturing of manmade fibres
Part 5 Types of Textured Yarns and their usage
Writer - Ujala Sharma (Textile technologist - LDCE, Ahmedabad)
