Examination of Colorfastness to Laundering of Naturally Dyed Fabrics using Contact Dyeing Method with Blueberries

Use of the contact dyeing method and natural mordants may have potential for reducing wastewater and developing a more sustainable method for natural dyeing. However, few studies have investigated colorfastness of naturally dyed fabrics using a contact dyeing method. Thus, the purpose of this study was to examine colorfastness to laundering of naturally dyed fabrics using contact dyeing and a natural mordant in relation to different mordant concentrations, mordanting procedures, and heating times. Mashed blueberries were sprayed on bleached cotton fabrics. Vinegar, a mordant, was applied in different concentrations: 25, 50, or 100% on the fabric. Mordanting treatment was applied in pre-, consecutive-, or postdyeing procedures. After dyeing, specimens were heated in a microwave for 10, 15, or 20 minutes and dried before colorfastness testing. AATCC 61 Colorfastness to laundering was conducted. Results indicated extended heat exposure, and pre-and post-mordanting procedures yielded better colorfastness to laundering. However, overall colorfastness to laundering of the contact-dyed cotton fabrics was poor to moderate, below acceptable performance standards for apparel products. Further research on different dye substances, natural mordants, heating methods, and heating times is needed to improve colorfastness of contact-dyed fabrics to laundering as well as to expand the use of sustainable contact-dyeing for consumers and the environment.

Keywords:Contact-dyeing method; Colorfastness to laundering; Naturally dyed cotton fabric using blueberries