Search

Committees Offer Technical Engagement for Corrugated Professionals, Paper360º July/August 2023

The Paper360° 2023 TOP 50 POWER LIST, Paper360º July/August 2023

Corra’s Journey, Part 4: The Creaser/Slotter Section, Paper360º July/August 2023

R&M FAULT ZONE SERIES:, Paper360º July/August 2023

Digital Transformation Can Help Balance Sustainability, Profitability, Paper360º July/August 2023

TAPPI Journal Summaries, Paper360º July/August 2023

TAPPI Journal Summaries, Paper360º July/August 2023

Facing the Pressures of Cutting the Maintenance Budget, Paper360º July/August 2023

The Future of Pulp and Paper Investments in the PNW, Paper360º July/August 2023

TAPPI News, Paper360º July/August 2023

External fibrillation of wood pulp, TAPPI Journal June 2023

ABSTRACT: Pulp refining produces external fibrillation consisting of fibrils tethered to fiber surfaces, in addition to loose fibrils and fines. Both contribute to a larger bonding area that increases paper strength, but tethered fibrils have less likelihood of being washed out during papermaking. This study postulates the mechanism by which refining produces external fibrillation and the optimum conditions for doing so.The postulated mechanism is surface abrasion during sliding of fibers in refiner gaps. External fibrillation occurs when forces are great enough to partially dislodge fibrils from fiber surfaces, but not large enough to break the fibrils. The refining intensities to achieve these forces were determined by a mathematical model and experiments using a laboratory disc refiner. The optimum intensities in terms of specific edge load (SEL) for chemical pulps were about 0.1 J/m for hardwoods and 1.0 J/m for softwoods. An extension of this study suggested that abrasion may also account for most of the energy consumed in the mechanical pulping process.