Drying Temperature and Hornification of Industrial Never-Dried Pinus radiata Pulps. 2. Voith Sulzer Refining

Dante Giacomozzi; Olli Joutsimo

Drying Temperature and Hornification of Industrial Never-Dried Pinus radiata Pulps. 2. Voith Sulzer Refining

2017

Dante Giacomozzi | Olli Joutsimo

The results from Voith Sulzer refining, porosity, and morphology studies of bleached Pinus radiata fibers showed the main effects described for hornification in dried pulps compared with never-dried pulps. Dried pulps showed higher deformations, measured as an increase in kinks. However, these deformations were shown to be reversible, based on zero-span development after Voith Sulzer refining. It is hypothesized that the observed changes in refining energy, drainability, tensile, zero span, bulk, and optical properties upon drying can be explained based on a combination of mechanisms including delamination and microfibril disarrangement and aggregation in the cell wall. Results suggested that drying-induced deformations and changes in orientation of fiber wall segments were similar to those observed in processing. Solute exclusion and nuclear magnetic resonance results also confirmed expected decreases in pore volume and average pore size for dried pulps (pores under 220 nm in size) and increase in cellulose inner crystallinity upon drying.

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