Spruce Woodmeal for Newsprint Applications: A Handsheet Study
Klaus Dölle *
Department of Paper and Bioprocess Engineering (PBE), College of Environmental Science and Forestry (ESF), State University of New York (SUNY), One Forestry Drive, Syracuse, NY 13210, USA.
Sandro Zier
Department of Packaging Technology and Paper Process Engineering, University of Applied Sciences Munich, Lothstraβe 34, 80335 Munich, Germany.
*Author to whom correspondence should be addressed.
Abstract
This study shows that spruce woodmeal can be an alternative cellulosic-based wood additive for newsprint applications. This study used unbleached wood flour produced from Spruce sawdust, ground and sieved to a particle size of 20-40 µm, 40-70 µm, 70-120 µm and 200-500 µm.
Woodmeal was added at levels of 2%, 4%, 6%, 8% and 10% based on oven dry fiber content. The basis weight of the newsprint handsheet manufactured was 80 g/m². The study revealed the following outcomes:
Woodmeal with a particle size distribution of 20-40 µm had the highest density followed by woodmeal with 70–150 µm, 40-70 µm, and 200-500µm. Increasing the woodmeal amount resulted in higher porosity. Woodmeal with a particle size distribution of 20-40 µm gave the lowest porosity and a particle size of 40-70 µm gave the highest porosity.
The Tensile index and burst index show decreasing values for the addition of all woodmeals and particle sizes. Woodmeal with strength additive and a particle size of 20 – 40 µm outperforms the other woodmeal types at additions of 2%, 4%, 6% and 8%. For woodmeal with a particle size of 70–150 µm at an addition of 2% and 4% an increased and similar burst index resulted for the handsheets.
First pass retention and ash retention increased for all wood flours with a maximum at 92% and 81% respectively for the wood flour with a particle size of 40-70 µm.
Keywords: Woodmeal, additive, papermaking, handsheets, paper properties, newsprint, recycled fibers.