KOZHIKODE: In a major research finding that would go a long way in conserving water in the water-intensive textile industry, researchers at Calicut University have come up with an eco-friendly process for manufacturing yarns.
Researchers say that the novel approach for ''sizing'' and ''desizing'' cotton and
polyesteryarns through a dry process using liquid and super critical
carbon dioxide (scCO2) and inexpensive sugar acetates will help the textile industry do away with huge amount of water currently used in the conventional process.
Sizing is the process of applying a protective adhesive coating upon the yarn to strengthen it to decrease breakages on the loom and attain maximum weaving efficiency. Conventional method of sizing involves drawing the yarn through a concentrated sizing solution- mostly starch and polyvinyl alcohol- and then drying it.
After the weaving process the yarn has to be ''desized'' by washing it with water which requires upto 2,500-2,1000 litres for 1,000kg of cotton yarn and drying it involves an energy intensive process.
Under the study, CU researchers investigated the possibility of utilizing liquid and super critical CO2 as an alternative medium for sizing and desizing of yarns using CO2 soluble compounds like Sucrose Octaacetate (SOA) and two other compounds as sizing agents.
In the study, the tensile strength of the yarn was found to have almost doubled for the cotton yarn when sized with SOA while it increased 60% for the polyester yarn. The study also found out that SOA can be completely washed off during the desizing process using scCO2.
The study was carried out by a team comprising Prof P Ravendran of the Department of Chemistry, University of Calicut along with researchers Anu Antony,
Anila Raj, Jyothi P Ramachandran of the department along with Resmi M Ramakrishnan of the Department of Chemistry, SNGS College, Pattambi and Scott L Wallen of the Division of Science, Arts & Mathematics,
Florida Polytechnic University, USA.
The study has been published in the prestigious international scientific journal ACS Sustainable Chemistry & Engineering.
"SOA was found to be the most ideal candidate as a size material in the CO2-based process. Sizing of both cotton and polyester yarns with SOA resulted in a smooth, uniform, and glassy coating and improved mechanical properties of the yarn as required for weaving," the study said.
Raveendran said that as the textile industry is increasingly under pressure to reduce consumption of water due the sustainability and environmental issues involved, the CO2- based sizing and desizing has the potential to be developed into an ideal zero-pollution technology for the industry with the additional advantage that the materials used are inexpensive and can be completely recycled.
Source: The Times Of India, India Monday, 13 August 2018