Abstract
The Direct to Film (DTF) heat transfer process is a recently developed transfer technology gaining widespread recognition and acceptance among users. DTF heat transfer offers vibrant colors, high image accuracy, no need for cutting the pattern edges, and low production costs, making it a popular process in the heat transfer industry. However, achieving high-quality DTF results is influenced by many factors, such as print smoothness, contour clarity, color vibrancy, wash durability, and transfer layer quality, all related to the process conditions. In this paper, we will systematically study and explain the factors affecting the quality of the DTF process.
Process Advantages
Vibrant color reproduction: Produces bright and clear colors. High-resolution image output: Provides sharp and detailed images. No post-printing edge trimming required: No need for cutting edges after printing. Cost-effective production: Affordable and efficient production process.
Quality Determinants
Print fluency: Affected by ink viscosity and nozzle performance. Edge sharpness: Influenced by film surface tension and ink spread control. Color vividness: Determined by pigment quality and ICC profile optimization. Wash fastness: Dependent on TPU powder adhesion and curing conditions. Transfer layer integrity: Relies on humectant removal and temperature control.
The heat transfer process utilizes an inkjet printer to print images onto a specially designed DTF (direct-to-film) transfer film (hereinafter referred to as DTF film). The ink used is specifically formulated to meet the requirements of the DTF process, allowing it to quickly solidify into a gel upon being printed onto the DTF film. The ink consists of cyan, magenta, yellow, black, and white colors. Light magenta, light cyan, and other colors can also be added to expand the color gamut. During printing, color and black inks are first applied to form the color image on the DTF film, followed immediately by the printing of white ink (hereinafter referred to as white ink) to cover the entire image. After printing, polyurethane hot melt adhesive powder (TPU) is evenly sprinkled onto the solidified white ink layer. The film is then dried to melt the TPU powder, forming a thin TPU layer. Finally, the image with the TPU layer is heat-pressed onto the substrate, such as a garment, and the DTF film is peeled off, completing the entire DTF heat transfer process.
