Harmful Chemical Residue and Printability of Different Textbook Papers

Abstract

Paper mills are currently pressed to reduce costs because of lack of resources and rising oil prices. Accordingly, paper mills are increasing the quantity of low-priced pulp using a ratio with relatively low whiteness by decreasing the use of high-priced, high-quality pulp. To solve the problem of deteriorated whiteness, paper mills regularly use a fluorescent whitening agent. In addition, with the increase of resource recycling and environmental problems, interest is growing in the use of recycled paper, which partially or completely contains recycled pulp. In this study, we investigated the content of hazardous heavy metals in recycled paper and paper stock produced in domestic paper mills and determined if other residues that are harmful to human health are present. Currently, no regulated minimum value is given for fluorescent whitening agents in Korea nor does sufficient research on the toxicity of these agents exist. Determining the amount of ink residue contained in recycled paper as well as the extent of harmful chemical residue resulting from the deinking and bleaching processes is necessary. This research also determined whether other chemicals added when producing recycled paper remained and subsequently analyzed the organic volatile compounds in the recycled paper and the existing produced paper to evaluate risk. We examined the influence of using waste paper on printing properties by performing comparative research on printing quality, e.g., printing color reproducibility of an existing textbook paper and recycled paper containing 30% old paper, trapping, contrast, halftone dot reproducibility, gloss, and rear shining. Test results concluded that fluorescent material, hazardous heavy metals, and the quantity of detected volatile organic material were not present at levels harmful to human health.