Suitability of Printing Materials for Heat-Induced Inkless Eco-Printing

Pyrolysis volatiles and the environmental impact of printing paper, newspaper, and silk were investigated to identify suitable materials for heat-induced eco-printing (HIEP) using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Furthermore, the printing effects of simulated HIEP and the material microstructures were studied using scanning electron microscopy (SEM). The results indicated that the toxicity of pyrolysis volatiles is highest for newspaper, followed by silk and then printing paper, whereas environmental friendliness follows the opposite trend. A high concentration of lignin, the basic structural element of which is phenyl propane, and the presence of halogens in the newspaper led to the generation of more toxic substances during the pyrolysis process. The benzene compounds and heterocyclic compounds in silk also produced high levels of toxic substances. Based on these findings and the higher color permeability of newspaper, printing paper was the most suitable material for HIEP and newspaper was the least suitable. Additionally, silk may still be used in HIEP in small amounts for the production of art, name cards, and clothing tags.