Evaluation of the Mordent Property of Coconut Husk Retted Water at Different Ages

Abstract

Today, the Brown Coir has become the leading agent in coconut husk fiber industry. It is used fiber for mattresses. The main step of Coconut brown coir fiber production industry is coconut husk retting process for the extraction of coir fiber in coir industry (Bhat & Nambudiri, 1971). For that the husk is steeped in water for 4-5 months in Sri Lanka (Menon & Pandalai, 1958). As a result of retting, large quantities of organic substances including pectin, pentosan, fat, tannins, and also toxic phenols are liberated into water. This coconut retted water is a waste product and a huge environmental problem. This research was focused in utilizing coconut retted water as a mordent in fabric dyeing industry.

A mordent is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue. The function of the mordant is to fix the dye on to the material or fiber. The dyeing industry these days pose severe environmental problems due to accumulation of the synthetic dyes and mordents. Majority of these synthetic dyes and mordents are not bio-degradable and consequently most of them are being banned. At this juncture, the use of natural coloring material as mordents and dyes play a very important role and now-a-days the industry is trying out on natural forms to avoid, environmental hazards.

Methodology

Uniform pieces of cotton fabric weighing 0.25 g were boiled in hot water bath at 100 ˚C to remove unnecessary particles in cotton fabric. Each piece was then boiled with coconut retted water at different ages (1 month, 2 months, 3 months and 4 months) separately in a water bath for another 20 minutes. A 0.25 mg/ml concentrated FeSO 4 was used as the control. Then, all cotton fabric pieces were allowed to dry. The dye preparations were made as 30 ppm solutions. The cotton fabric pieces which were treated with coconut retted water at different ages were impregnated with dye preparations in a boiling tube and heated in a water bath at 60°C for 10 to 20 minutes. Then, they were boiled over a Bunsen flame for 5 minutes for complete adhesion of the dye on to the fabric. These pieces were then allowed to dry to complete the process. Nine trials were carried out with each sample of coconut retted water with sky blue color. The process was repeated with FeSO4 impregnated cotton fabric pieces and with cotton fabric pieces without any mordent as positive controls and negative controls respectively. Nine trials were conducted for both positive and negative controls. After completing the dyeing process, all cotton fabric pieces were subjected to visual comparison with a standard color chart by 30 individuals.

To evaluate the effect of coconut retted water as a mordent, colored cotton fabrics were washed a mild acid solution, a mild base solution and a detergent solution. Amount of washed out dye was measured by measuring the absorbance of solutions at 340 nm.