Post-treatment of humic acid-dyed paper

摘要

Humic acid-dyed paper suitable for use as wrappers for smoking articles is post treated with magnesium sulfate to fix or render the humic acid insoluble. Paper treated in this manner provides a product of acceptable brown color. Smoking articles wrapped in the treated paper evolve a reduced amount of carbon monoxide on smoking under normal conditions in comparison to currently available brown papers stained with humic acid.