Date of Defense

Spring 4-9-1996

First Advisor

David Peterson, Paper and Printing Science and Engineering

Second Advisor

Ellsworth Shriver, Paper and Printing Science and Engineering

Third Advisor

Brian Scheller, Paper and Printing Science and Engineering


Currently, petroleum inks are used most frequently in the printing industry. Concerns have arisen surrounding the use of petroleum inks due to several environmental problems. Petroleum inks are known to emit volatile organic compounds during application and cure. These inks contain cycloparaffins, paraffins, measurable amounts of metals, and hydrocarbons. Consumers are interested in the use of soy inks as an environmentally friendly alternative. The paper industry will be supportive of the use of soy inks if it is clear that soy inks will be recyclable when they enter the post-consumer waste stream. It was the intent of this project to examine the use of soy and petroleum inks when printed on two different substrates for recyclability. The two paper sources were a virgin fiber sheet and a post-consumer recycled sheet. The experiment was conducted by slushing up printed samples separately, and sending them through a flotation cell and sidehill screen deinking system. Handsheets were made of "cleaned" pulp stock image analysis was used to determine the change in brightness and dirt removal. Results were that when recycling the virgin paper through the deinking system, both ink types showed good overall brightness and dirt removals. however, the petroleum ink demonstrated better overall values than the soy ink. Although not better overall, the soy ink showed a faster rate of dirt removal than the petroleum. When recycling the post-consumer paper through the deinking system, no appreciable differences were observed for either of the two inks. The post-consumer paper source was more difficult to deink than the virgin fiber paper source. The virgin fiber paper source was capable of faster dirt removal rates than the post-consumer paper source. Soy ink samples demonstrated better overall brightness and dirt removal on both paper sources after a minimum of 30 minutes in the flotation cell. One important conclusion that was derived from this project was that both inks were capable of good recyclability. Further work could be done to examine the impact of deinking a mixed-waste streatm with both inks together, as well as separating the papers to evaluate the importance of the presence of lignin.

Access Setting

Honors Thesis-Campus Only