'Starch amide produced from TamarindKernel Powder is cooked along with dissolved ammonia in alkaline polyvinylalcohol solution used in sizing of jute yarns resulting at least 2% increase inweaving efficiency'
Abstract
An aqueous liquid of polyvinyl alcohol (cold) treated withparticular proportions of urea and hydrated sodium acetate to produceacetamide, carbamic acid, carbonic acid and ammonium hydroxide and added in anamount of 13% to 19% by weight with Tamarind Kernel Powder (TKP) which is cookedfor sizing of jute yarns show an increase in elongation at break of jute yarnsby 4% thus reduces the warp breakage rate by 30% to 40% in power looms as wellas in Sulzer looms and weaving shed efficiency is increased by 2% to 4%.
Introduction
During the formation of fabric by weaving machine (loom) intextile mill, the warp yarns (the set of yarns coming from the beam which issituated at the back of the loom) undergo a lot of stress, strain and abrasion.The reason for stress is the backward and forward pull of the warp yarns andthe cause of strain is the mechanical splitting of the warp yarns in order topermit the weft yarn (the single yarn that is traversing across the loomthrough the splitting of warp yarns in order to interlace the warp yarns). Thecause of abrasion is the movements of warp yarns through different fast movingmachine parts and also friction with the shuttle.
So, before the warp yarns go to the loom for weaving, theyrequire an external protection. The process of this external protection of warpyarns is called sizing. The main size ingredient used for jute yarn sizing isTamarind Kernel Powder (TKP), a low cost starch. When a cooked starch paste isformed in addition to other chemicals, water and heat, a viscous paste havingadhesive property as well as thin film forming property is generated. Thisstarch paste should have the capability to coat individual yarn and to formthin, smooth and elastic film on the surface of jute yarn.
Jute yarns are mainly sized with cooked aqueous solution ofTamarind Kernel Powder (TKP) along with Carboxy Methyl Cellulose (CMC) or withany sort of cheap natural gums. Chemically the natural gums are for most of thepart polysaccharides, but they also have some uronic acid residues. Gumsgenerally used in Indian jute mills are gum Arabic, Senegal, Indian gum orBabul gum. Some Indian jute mills do not use gum at all. However an antisepticagent is always used with size paste like salicylic acid, salicyl anilide orsilica fluoride.
The films of the above size ingredients when dried becomehard and brittle. In cotton industries, to decrease brittleness of the starchfilm lubricants like sulphonated oil, T.R. oil, cottonseed oil or some fattyacids along with softener like tallow, paraffin wax etc. and hygroscopic agentslike chlorides of zinc, magnesium, calcium or simply glycerin are used.
About the Author
The authoris associated with College of Textile Technology, Hooghly, WB, India.
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