During summer-time storing wood loses moisture and brightness. Storing induced wood dryness may cause problems in mechanical pulp production. Norway spruce logs were stored in piles over summer and compared to fresh wood as a raw material for TMP. The reduced wood moisture content does not require changes in thermomechanical pulping as long as the moisture content remains above the fiber saturation point. The amount of colored substances in wood increases already during the storing, and further in the refining, resulting reduced pulp brightness. This brightness loss can be mostly recovered by peroxide bleaching. However, at high brightness levels of 75-80%, the use of stored wood can increase the required peroxide charge by 8-12 kg/BDt. Combined washing and pressing treatment of the chips provides further brightness improvement.
|Title of host publication||Proceedings of International Mechanical Pulping Conference 2011|
|Publisher||Chinese Academy of Forestry|
|Publication status||Published - 2011|
|MoE publication type||B3 Non-refereed article in conference proceedings|
|Event||International Mechanical Pulping Conference, IMPC 2011 - Xi'an, China|
Duration: 26 Jun 2011 → 29 Jun 2011
|Conference||International Mechanical Pulping Conference, IMPC 2011|
|Abbreviated title||IMPC 2011|
|Period||26/06/11 → 29/06/11|
- thermomechanical pulp
- wood storage
- chip pretreatment
Sirviö, J., Särkilahti, A., Liitiä, T., Fredrikson, A., Salminen, L., & Nurminen, I. (2011). Prolonged wood storage causes mainly brightness problems for TMP. In Proceedings of International Mechanical Pulping Conference 2011 (pp. 23-26). Chinese Academy of Forestry.