1. Dinesh Fernando & Geoffrey Daniel
CRUW
COST FP1105 Workshop, Coimdra
Morphological Ultrastructural Characteristics of Fines Fraction Produced during HC and LC refining of TMP for Fundamental Understanding of Property Development
Dinesh Fernando & Geoffrey Daniel
Center for Research on Ultrastructure of Wood Fibers (CRUW)
Dept. of Forest Products
Swedish University of Agricultural Sciences (SLU)
Uppsala, Sweden.
08 May Dinesh Fernando

2. Results and Discussions
CRUW
Results and Discussions
Morphological characteristics of fines produced during HC and LC refining
40 µm
Primary pulp fines
Similar properties between HC & LC pulps; - tensile index (~40 Nm/g), - density (398 kg/m3), - light scattering (59 m2/kg)
But with a lower energy (20%) from LC refining
HC Fines
LC Fines
A considerable differences in ultrastructural characteristics between HC & LC Fines
- Arrowheads; broader fibrils
- Arrow; String-like
- Arrows; Flake-like
08 May Dinesh Fernando

3. Results and Discussions
CRUW
Results and Discussions
HC fines
A wide variation in the morphology;
- predominantly ribbon-type fibrils from S2 layer
- ranging from narrow string-like to broad sheet-like fibrils
- broad cellulose fibrils possess high bonding potential and explain high density and strength properties
- SL=sheet-like fibrils, LS=lamellar sheets
LC fines
Marked by very narrow strings- or thread-like ribbons; - good scattering structures (1-7) - provide required porous structure (a-g) for better light scattering
Lacked broader fibrils such as LS and SL and explain lower strength compared to HC pulps
2 µm
0,5 µm
08 May Dinesh Fernando

4. Thank you ! Acknowledgments
CRUW
COST Action Workshop, Edinburgh
Acknowledgments
Dmitri Gorski (now at Metso, Sweden) from Norske Skog, Halden, Norway.
Financial support to CRUW (Centre for Research on the Ultrastructure of Wood Fibers) from VINNOVA, Eka Chemicals, Holmen, SCA, Smurtfit Kappa, Stora Enso & Södra Cell is gratefully acknowledged.
Thank you !
Center for Research on Ultrastructure of Wood Fibers
Dept. of Forest Products
Swedish University of Agricultural Sciences
Uppsala, Sweden.
08 May Dinesh Fernando