The Microstructure of Paper after Heat-Induced Inkless Eco-Printing and its Features.

Microstructural changes in paper after heat-induced inkless eco-printing (HIEP) and pyrolysis productions of paper were investigated by scanning electron microscopy and pyrolysis-gas chromatography/mass spectrometry (Py-G/MS). The results were as follows: (1) When the heat-induced temperature is between 350°C and 600°C, slight scratches are left on the paper surface after scan printing, but click printing leaves obvious concave indentations. Both of these printing methods can create a clear and clean boundary with no significant carbonized microstructure. (2) Experimental studies show that paper undergoes true pyrolysis at 500°C. The simulated printing test shows that the fibers on the paper surface exhibit a yellow discoloration that meets printing requirements. (3) Compared with current laser printing techniques and laser inkless eco-printing (LIEP), HIEP has the advantages of avoiding the de-inking process during paper recycling and preserving paper strength better than LIEP. [ABSTRACT FROM AUTHOR]