Studies of Wood and Wood Handling

By studying wood, one can obtain insights crucial for answering several important questions within the pulp and paper industry. One of these questions is whether it is possible to introduce new wood species into production while maintaining the desired properties of the resulting pulp.

At RISE, we conduct comprehensive studies on various types of wood to assess their suitability for pulp production. Our investigations focus on key areas, including the economic value of fiber materials, which involves analysing the wood's composition and quality in relation to production costs and the profitability of the resulting pulp.

We also evaluate the processability of wood, examining its chipping characteristics, ease of grinding, and impact on production efficiency and product quality. Additionally, we assess the properties of the resulting pulp and paper, ensuring they meet desired criteria such as strength and brightness.

Optimising Debarking for Cost and Quality

Debarking studies are key to balancing cost and quality, leveraging factory proximity and expert knowledge. Identifying the most efficient debarking method can yield significant savings. For example, a facility with a wood cost of 1 billion kronor can save 10 million kronor by reducing wood losses by just 1%. Consistently processing varied wood sources improves pulp quality through uniform blending.

A debarking study starts with selecting 200 logs from different batches. A section is cut from each to avoid harvest or transport damage. Bark and sapwood are removed to measure bark content, dry matter, density, and diameter. The logs are then processed through the debarking drum, where samples assess wood loss, bark content, and debarking efficiency.

Drum residence time is measured by color-marking 100 logs and tracking their movement. Since heavier, longer logs exit faster, selecting a representative sample ensures accurate analysis. These insights help refine drum operation and wood mix for optimal efficiency.

Optimising Wood Blending in Pulp Production

Understanding how different wood species interact with processes and affect the final product is key to informed raw material decisions. A key question is how much of a specific wood can be blended without compromising pulp quality, requiring optimal blending ratios to balance performance and resource efficiency.

Chip size also influences pulp properties, affecting structure, strength, and process efficiency. Evaluating these effects ensures optimal production and consistent quality.

At RISE’s pilot cooking facility, up to six wood species or chip fractions can be processed separately in the same cooking step, allowing detailed studies. After defibration, we analyse yield, kappa number, viscosity, rejects, chemical composition, and physical properties as needed. Chip thickness is crucial, especially in kraft cooking, for proper impregnation.

After cooking, pulps undergo bleaching to assess bleachability, strength, and optical properties. With RISE’s custom refiner and experimental paper machine, we can further evaluate paper properties, providing a complete material analysis.

Wood investigations are in high demand, particularly as wood prices fluctuate. Blending species like eucalyptus with birch or testing aspen blends requires careful control to maintain quality. In Europe, species such as poplar, oak, and beech may also be of interest. In cases where chips aren’t available, we process logs in-house, ensuring reliable testing for new raw materials.