Dyeability of 3D Printed Thermoplastic Polyurethane (TPU) Material Using Turmeric and Lac Natural Dyes

In this study, natural dyeing studies using turmeric and lac were conducted to test their respective utility as yellow and red dye in 3D-printed thermoplastic polyurethane material. For this purpose, turmeric and lac were first extracted with distilled water to analyze their color characteristics. Next, the extracted turmeric and lac dyes were dyed in 3D-printed thermoplastic polyurethane material under different dyeing conditions to examine their dyeability. The dyed thermoplastic polyurethane material was also investigated in terms of its color fastness to sunlight, washing, and rubbing. The experimental results confirmed that the turmeric extract was composed of three mixtures of dimethoxycurcumin, bis-dimethoxycurcumin, and curcumin, and that the lac extract was composed of two components: laccaic acids A and laccaic acids C. Thermoplastic polyurethane material dyed with turmeric dye showed Y-series, while thermoplastic polyurethane material dyed with Lac dye showed YR-series. Both dyes showed the Lamgmuir-type isothermal adsorption curve in which the amount of dyeing no longer increased beyond a certain level of initial dye concentration and dyeing time. Under the experimental conditions of this study, in the case of turmeric dye, the optimum dyeing conditions were determined to be 20% concentration, 60 degrees C temperature, and 20 min. Meanwhile, the optimal dyeing conditions for lac dye were determined to be 60% concentration, 90 degrees C temperature, and 30 min. Thermoplastic polyurethane material was dyed under each optimal dyeing condition, and as a result of measuring the light fastness, washing fastness, and rubbing fastness of the resulting material, relatively high color fastness was obtained. The results showed that a high dyeing amount and color fastness were obtained solely using natural dyes without any synthetic dyes, thus showing the potential usage of these natural dyes in actual production.

Automated summary

In this study, natural dyeing using turmeric and lac was conducted to evaluate their effectiveness as yellow and red dyes in 3D-printed thermoplastic polyurethane material. The results confirmed the composition of the turmeric and lac extracts and their optimal dyeing conditions. The dyed thermoplastic polyurethane material exhibited high color fastness, indicating the potential usage of these natural dyes in actual production.