Sustainable Washing for Denim Garments by Enzymatic Treatment

Abstract Denim garment is the most preferred of today’s youth. This paper presents the effect of enzyme wash using cellulase enzyme on the properties of denim garments to develop novel design and fashion. Three parameters in enzyme washing namely concentration of enzyme, washing temperature and time at pH 5.5 were considered. To investigate the optimum washing condition, indigo dyed cotton denim garments (trousers) were chosen and processed by enzyme with the concentration of 0.5% to 3.5%, temperature 40°C to 70°C and time 20 min to 60 min for the achievement with desired worn and aged effect. The effect of each parameter is discussed, and denim garment’s properties like tensile strength, elongation at break, weight loss, stiffness, water absorption, shrinkage, color fading and morphological values by SEM were evaluated. The optimized washing condition for the best value is 2% enzyme concentration at 55°C for 40 min. Keywords: denim garment, cellulase enzyme, tensile strength, sustainability
1. Introduction Eco-friendly sustainable garment design is the new challenge for garment designers and producers, because the consumers are concerned in eco-fashion in the last decade. In the fast changing fashion trends, all are now motivated to practice sustainability in design and production processes. Denim is very strong, stiff and hard wearing fabric. Denim garment (Jeans) washing is known as one of the widely used finishing treatment that has vast usage in textile sectors because of creating special appearance and making fashionable and wear comfortable garments of the present day world and commonly used. Without finishing treatments, denim garment is uncomfortable to wear, due to its weaving and dyeing effects. For this it essentially needs a finishing treatment to make it softer, smooth and comfortable to wear performance. Popularity of garments was specially on denim garments in the World market have been increasing day by day3 . To meet up the quick change of current demands of customers, technologists are trying to introduce new designs and fashion on denim garments by using different washing methods. The most commonly denim washing methods are enzyme wash, bleach wash, acid wash, normal wash, stone wash, etc. Among the washing methods, enzymatic method is widely used method in industry4,5. However, enzyme treatment of cellulosic garments degrades cellulose at the ends or in the middle of the cellulose chains, yielding shorter chain cellulose polymers, and reduces its mechanical strength6 . But cellulase treatments have been successful at improving fiber flexibility, desirable appearance and soft handle of cotton denim garments7 . So, enzyme washing using cellulase is chosen for this work.
In this study, a sustainable and environment friendly process have explored for denim washing with cellulase enzyme that developed new design and fashion and is produced denim garments as a value-added product with high wear performance to satisfy customer’s need. In addition, the effects of various wash parameters using cellulase enzyme on the properties of denim garments have investigated and characterized. 2. Materials & Methods 2.1 Materials Denim fabric was collected from Beximco Textile Mills Ltd., Dhaka, Bangladesh and garments (trousers) were manufactured in the sewing lab. These comprised 100% cotton fabric (GSM 318), twill, weave 3/1, construction 70 x 42 / 10 x 9, indigo dyed fabric. Garments were enzyme washed using the standard recipe8 . Genzyme SL, (cellulase enzyme, Sri Lanka); detergent (Kohinoor, BD); Bio.D. (Biological detergent as desizing agent, Germany); soda ash (China), acetic acid (China) and textsoft softener (Germany) were purchased. 2.2 Methods 2.2.1 Desizing Treatment Denim trousers were desized using detergent, desizing agent and soda ash. This treatment was conducted in liquor containing soda ash (1.2 g/l), detergent (0.6 g/l), and desizing agent (0.6 g/l) and material to liquor ratio of 1:30 in a laboratory scale sample washing machine at 60°C for 20 min. The garments were then washed with hot water (70°C) followed by cold water wash.
2.2.2 Enzyme (Cellulase) Treatment Desized trousers were treated using cellulase enzyme. This process was conducted in liquor containing acetic acid (1g/l) at pH 5.5 and material to liquor ratio of 1:30. The enzyme treatment was carried out at different concentrations of Genzyme SL (0.5 – 3.5%), temperatures (40 – 70°C) and treatment time (20 – 60 min). After desired time the temperature was raised to 90°C for 1 min to stop enzyme action. The denim garments were then washed with hot water then washed with cold water. Finally, garments were softened with Textsoft softener (1 g/l) at 40°C for 10 min. 2.3 Hydro-Extracting and Drying Processes After treatment, the washed denim trousers were squeezed in a laboratory scale hydro-extractor machine (Zanussi, Roaches , England) at 200 rpm for 3-4 min to remove excess water and then dried in a steam drier (Opti-Dry, Roaches, England) at 75°C for 35-40 min. Treated denim garments were then evaluated in testing machines and characterized of their physical and mechanical properties to determine product performance. 2.4 Testing and Analysis Treated all denim trousers were conditioned at 65% RH and at 20°C for 24 h before testing according to BS EN ISO 139:2005 and ASTM D1776.

• Moisture regains and moisture content (%) was calculated from the difference in total fabric weight and oven dry weight according to BS 4784-2:1998 and ASTM D 1909. • Tensile strength and elongation at break was determined by the US Standard Grab test method according to ASTM D 5034 and ASTM D 1682. • Dimensional changes (shrinkage %) was calculated from the difference in fabric length before and after washed garment according to AATCC test methods 96-2009,135-2010 and 150-2010 ; ASTM D 2724, BS 4931. • Weight loss (%) in fabric was calculated from the difference in fabric weight (GSM) before and after the treatment according to ASTM D 3776. • Change in the original color shade of the fabric was rated using gray scale for color change according to AATCC test method 61. • Stiffness was measured from the bending stiffness in fabric by Shirley stiffness tester according to BS 3356-1990. • Water absorption was measured in fabric from the differences in rate of uptake according to BS 3449- 1990. • SEM was studied using a scanning electron microscopy (Hitachi, model-S 3400 N, Japan).

সূত্র: নেটে থেকে সংগৃহিত।
তারিখ: ডিসেম্বর ০৩, ২০২১

রেটিং করুনঃ ,