Optimization of Process Conditions of Cotton Fabric Dyeing with Nettle Leaf Extract for Antibacterial Application Using Central Composite Design

ABSTRACT

In this study, all conditions of the natural dyeing process of cotton fabric with antibacterial efficiency, extracted from the leaves of the nettle were optimized using a central composite design. The optimized dyeing conditions are: concentration of 16.943 g, temperature of 50 °C, time of 40 min, and the color strength obtained at optimum condition was 1.53. The Nettle natural dye is applied to cotton fabrics by the Pad-Dry-Cure method for imparting antibacterial properties to the textile product for apparel applications. Biomordants were applied on scoured cotton fabric in the pre-mordanting process of dyeing. Color characteristics of the dyed fabrics were measured by CIE L*a*b* value using a spectrophotometer. Gram-positive (S. aureus) and gram-negative (E. coli) bacterial assessments were performed quantitatively using the AATCC-100 test method. The results provided evidence that the treated fabric exhibits higher antibacterial efficiency of gram-positive and gram-negative bacteria by 96.5–98% reduction compared to the control samples, respectively. The one having the highest antibacterial activity was washed 15 times under the same conditions and samples were taken after 1, 5, 10, and 15 washes. They retained nearly 91% S. aureus and 94% E. coli activity up to 10 launderings against the two bacteria.

摘要

在本研究中，采用中心复合设计对从荨麻叶中提取的具有抗菌效果的棉织物的天然染色工艺的所有条件进行了优化. 最佳染色条件为: 浓度16.943 g，温度50°C，染色时间40 min，最佳染色条件下的显色强度为1.53. 荨麻天然染料通过垫干固化法应用于棉织物，以赋予服装应用的纺织品抗菌性能. 在纯棉织物的预媒染染色过程中，应用了生物絮凝剂。使用分光光度计通过CIE L*a*b*值测量染色织物的颜色特性. 使用AATCC-100测试方法对革兰氏阳性（金黄色葡萄球菌）和革兰氏阴性（大肠杆菌）细菌进行定量评估. 结果证明，与对照样品相比，经处理的织物对革兰氏阳性菌和革兰氏阴性菌的抗菌效率分别降低了96.5-98%. 具有最高抗菌活性的一种在相同条件下洗涤15次，并在洗涤1次、5次、10次和15次后取样. 经过10次洗涤，它们保留了近91%的金黄色葡萄球菌和94%的大肠杆菌活性.

KEYWORDS:

• Nettle leaf
• Natural dye
• Cotton fabric
• Pad-Dry-Cure
• Staphylococcus aureus
• Escherichia coli

关键词:

• 荨麻叶
• 天然染料
• 棉布
• 衬垫干固化
• 金黄色葡萄球菌
• 大肠杆菌

Highlights

• The nettle plant leaf is used as raw material for naturally dyed cotton fabric.

• The optimum dye extraction time does not exceed 53 minutes.

• The color value and antibacterial activity property were studied on cotton fabric.

• The dyed fabric shows superior antibacterial activity against S. aureus and E. coli.

Acknowledgements

The authors are thankful to Dire Dawa University Institute of Technology, Dire Dawa, Ethiopia, for continuous encouragement and support for this work.

Disclosure statement

No potential conflict of interest was reported by the authors.