The Effect of Fines on the Surface Characteristics of Recycled Paper

With the steady increase in recycling comes an increasing need to understand the mechanisms involved with reused wood fibers. The purpose of this experiment is to determine the effects of fines on the surface characteristics of recycled paper, and to predict how an increase or decrease in fines loading might affect printing. To meet these objectives, fines were removed from both virgin pulp and mill broke of similar composition. Each fines fraction was then reapplied to each long fraction at 0, 5, 10, and 15 percent loading by weight. British handsheets were made and evaluated for surface strength, absorbency, smoothness, and optical properties. Fines from recycled stock were shown to be much less active than fines for virgin stock. Increasing recycled fines showed only a very slight improvement in surface strength, a reduction in liquid penetration, increased scattering/opacity, and slightly decreased brightness. No conclusions could be made for effects on smoothness. These results indicate that increased recycled fines would increase hold out and reduce ink penetration and ink show through. Overall, with the exception of opacity, fines appear to play a much smaller role in paper making when the paper is recycled