Fundamental study on developing wood powder as an additive of paperboard

Abstract

In this study, we investigated the applicability of wood powder to the manufacture of paperboard. Laboratory studies and mill trials were carried out to develop wood powder suitable for a functional additive of paperboard and to determine its ability to improve the sheet bulk and to reduce the drying steam. The wood powder was manufactured by grinding and screening. The maximum particle size was a critical factor affecting the applicability of the wood powder as an additive. In the laboratory studies, handsheets containing the wood powder were made, and their physical strength properties were analyzed. The wood powder increased the sheet bulk and decreased the physical strength of the sheets. The mill trials were performed in a white lined chipboard (duplex board) mill, and the wood powder was added to the middle ply of Sunny Coated (SC) 300 g/m(2) and 400 g/m(2), a commercial grade of duplex board that contains a back ply made of deinked pulp. As the level of the wood powder was increased, the bulk increased linearly, and the drying steam decreased significantly. We conclude that well-manufactured wood powder can be used as an additive for paperboard and is beneficial with respect to bulk improvement and drying steam reduction. Application: Wood powder can be used as an additive to improve paper thickness and to decrease drying energy in a duplex-board mill. Because this material is added to the middle ply of paperboard, papermakers can achieve bulk improvement and steam reduction without the deterioration of paper strengths.