High-Quality Wood Handling a Prerequisite for High-Quality Mechanical Pulp, 2005 Engineering, Pulping & Environmental Conference

Mechanical pulp properties are to a great extent dependent on the properties of the raw material used. Thus, careful wood handling is needed. Especially the high initial brightness of the wood raw material needs to be protected. Brightness is suffered greatly during negligent wood storage and handling chain, leading to e.g. increased need for bleaching. Modern alternatives for careful storage and also pulpwood handling and pre-treatment prior to mechanical pulping processes exist.

Through a mechanical grinding ((P)GW) and refining (TMP) process it is possible to control the pulp properties sufficiently. Therefore, mechanical pulps can be used in a variety of paper products, covering grades from board and tissue to different printing papers. By developing the present wood storage and wood handling methods, it is evidently possible to improve the properties of the raw material and hence avoid losses in quality. The major decline in pulpwood quality appears during the different stages of wood handling and wood storage and is dependent on the storage method, storage time and original wood properties.

In the future, a modern (P)GW-mill might be able to produce pulp with superior properties. This could include highly fibrillated fibres with good drainage properties, and simultaneously provide high brightness. This depends, of course, on the end-product requirements. However, an option to produce “tailor-made” PGW through pulpwood pretreatments might offer a substitute to TMP.