eCite Digital Repository

Process factors affecting colloid stability and deposit formation in manufacture of newsprint from TMP and recycled fibre


Richardson, D and Lee, R and Stack, K and Lewis, T and Garnier, G, Process factors affecting colloid stability and deposit formation in manufacture of newsprint from TMP and recycled fibre, Appita Journal, 65, (4) pp. 323-330. ISSN 1038-6807 (2012) [Refereed Article]


Copyright Statement

Copyright 2012 Appita

Official URL:


Formation of pitch and sticky deposits through the destabilisation of colloidal material present in paper manufacture continues to be a challenge in improving machine efficiency in newsprint manufacture from a furnish comprising thermo-mechanical pulp (TMP) and recycled fibre (RCF), and in an environment where water usage efficiency is at best practice. Findings from laboratory studies that have investigated colloid structure, impact of multiple and multi-valent cations, pH, temperature, shear and dissolved organic matter on Pinus radiata extractive colloid stability have been used , along with observations of process conditions in Norske Skog’s Albury mill to determine which properties are most important in maintaining colloid stability.

Developments in our understanding of wood extractive colloid structure have led to an explanation as to why pitch deposition is more likely during summer months. A parameter called the "ester to acid ratio" has been shown to exhibit both short and long-term trends when applied to process stream extractive levels. This greater propensity for deposition during summer months is exacerbated by elevated soluble calcium levels during summer time. Dissolved organic wood polymers also affect colloid stability and their behaviour is further modified by the presence of soluble calcium. More stable colloids are obtained under conditions of neutral pH, avoidance of downward temperature shocks and avoidance of shear forces.

Item Details

Item Type:Refereed Article
Keywords:pitch deposits, colloid stability, wood extractives, resin acids, fatty acids, glycerides, TMP, recycled fibre, newsprint manufacture
Research Division:Chemical Sciences
Research Group:Physical chemistry
Research Field:Colloid and surface chemistry
Objective Division:Manufacturing
Objective Group:Wood, wood products and paper
Objective Field:Paper products and pulp
UTAS Author:Lee, R (Mr Roland Lee)
UTAS Author:Stack, K (Dr Karen Stack)
UTAS Author:Lewis, T (Associate Professor Trevor Lewis)
ID Code:79784
Year Published:2012
Web of Science® Times Cited:4
Deposited By:Chemistry
Deposited On:2012-10-03
Last Modified:2017-10-25
Downloads:495 View Download Statistics

Repository Staff Only: item control page