In recent years, as consumer’s awareness about green product are being developed in consumption patterns to harmoniously coexist with nature, the demand for eco-friendly products has been growing significantly. In the textile industry, green marketing and eco-friendly products has become a key issue to meet customer’s demand for environmental sustainability and multifunctionalities. For that reason, eco-friendly natural fibers derived from palms, bamboo, kenaf, reed, protein fiber, corn fiber and mulberry fiber are widely used in pulp and paper production as well as for various textile uses. Among them, Hanji yarn, the mulberry paper yarn, which is neutral pH paper yarn (7.5∼9.0), is one of promising materials that can be utilized in various textile fields due to its long lifespan, high preservability and excellent properties such as deodorization, antimicrobial, fast drying, lightweight, and so on. Despite these advantages, some important challenges associated with manufacturing process are still to be addressed for more widespread utilization and higher quality of Hanji yarn.
Knitted fabrics made by Hanji yarn cause serious dyeing problem due to color difference (ΔE) between regular parts and defect parts, which results from fiber fineness. To solve color difference appeared between them, this study investigated the effects of pretreatment and penetrating agent on dyeing properties of Hanji knit fabrics. We found that the use of penetrating agent increased the water absorption in Hanji yarn and pretreatment using surfactant (sera wash®) and sodium hydroxide had more significant effect. In addition, strong bleaching using hydrogen peroxide reduced color difference between regular parts and defect parts, finally improving the dyeing properties without significant loss of tensile strength. The results of the present study provide an attractive alternative to overcome dyeing problem, thereby increasing the potential of Hanji yarn as an eco-friendly material.