Rheological characterization and simulation of chitosan-TiO2 edible ink for screen-printing

Abstract

Traditional ink owning harmful components has caused many problems, so this paper developed chitosan-TiO2 edible inks and used it as the model to study the relationship between rheology and printing, for better development of edible inks. Rheological properties and the corresponding fitting were investigated. The developed ink exhibited non-Newtonian behavior, shear-thinning behavior, and temperature-dependent properties. Shear strain, frequency and temperature had great impact on modulus of inks. Low J(t) (compliance) values reflected strong material structure and the related final recovery ratio attained 65.9%. Based on the fitting results, the screen-printing simulation were further researched for closer practical application. The recovery rate reached 55% with high initial recovery coefficient (K3 = 10.7), indicating that the ink recovered sooner to the high viscosity after the shear was released and was suitable for printing. The ink was also printed on coated paper. Fastness was up to 91% and scratch resistance achieved H. The print effect on black cardboard and PET film was also excellent. The prepared edible ink provides a novel alternative to traditional ink and holds great potential in printing industry, especially on food.