What is Yarn Preparation?
Yarn preparation is very important for the efficient running of the subsequent processes. This fact even becomes even more obvious with the ever increasing production rates in weaving and knitting. Besides, yarn preparation for weaving and knitting is crucial for achieving high-quality fabric.
Yarn preparation involves those processes that improve the yarn’s weaveability or knittability. Yarn may be grey or dyed which are used for weaving and knitting. Yarn is the basic element for weaving and knitting. Yarn preparation is very essential for both weaving and knitting. Because the yarn which are collected from spinning can not directly used in weaving and knitting. Before using it in loom or knitting machine it is processed by many ways. These all ways are called yarn preparation.
Importance of Yarn Preparation for Weaving and knitting:
- To wind yarn uniformly on to a suitable package.
- To improve weaving efficiency.
- To improve or maintain higher quality of fabric.
- To clean the yarn for better appearance and performance.
- To remove yarn fault.
Yarn Preparation for Weaving:
Yarn preparation for weaving depends on fundamental understanding of the yarn to be processed and the knowledge of stresses to which the yarn would be subjected to during weaving. Production of woven fabric starts with yarn preparation methods like winding, warping and sizing. In order to produce a weaver’s beam with a few hundred to a few thousand number of warp yarns and their length (m) on the beam, the spun yarns on small packages produced during the spinning process undergo the following yarn preparation processes for weaving purposes:
- Winding
- Warping
- Sizing.
During the spinning process, as the yarn is produced, it is generally wound on a package called a spinner’s package. The length of yarn put on this package can be from a few hundred to a few thousand meters depending on the length and diameter of the spinning package as well as the count, i.e. linear density of the yarn. These small packages produced on the ring spinning machine are mostly unsuitable for the efficient running of the next processes, i.e. warping, twisting and weft winding (pirn winding), making a winding process necessary.
The sizing process is optional and is carried out mostly for single spun cotton yarns. Woollen and worsted warp yarns are normally produced as two-fold yarns (two yarns twisted together). As such, they do not require a sizing process, in which case only winding and warping preparatory processes are carried out.
Required Properties of a Weaving Yarn:
- Yarn must be uniform.
- It should be less hairy and more clean.
- It must be free from knot.
- It should have enough strength, so that it is not broken by friction in weaving process.
- Yarn must be free from neps, slubs and loose fibers.
- It must be elastic.
- Uniform sized yarn is required.
- Yarn must be free from hairiness.
- Uniformly sized
Preparation Requirement for Weaving Yarn:
a) Warp Yarns:
- Yarns must be aligned properly
- Yarn strength must be increased
- Yarn hairiness must be decreased
- Yarn smoothness must be increased
- Yarn elongation and flexibility must be sustained
b) Filling Yarns:
Yarn must be wound properly and on a suitable package for high speed unwinding.
Yarn Preparation for Knitting:
Proper yarn preparation ensures efficient knitting operations and high-quality fabric production. Yarn preparation for knitting involves fiber selection, spinning, winding, twisting, heat setting for synthetics, lubrication, conditioning, and quality inspection. These steps ensure the yarn is strong, pliable, and free of defects, ready for efficient knitting and high-quality fabric production.
Preparation Requirement for Knitting Yarn:
a) Weft Knitting:
- Yarn friction must be decreased
- Fiber shedding must be decreased
- Yarn smoothness must be increased
b) Warp Knitting:
- Yarn friction must be decreased
- Fiber shedding must be decreased
- Yarn smoothness must be increased
- Yarns must be properly aligned for introduction to knitting needles
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Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
