Canadian Forest Service Publications
Cost implications for thermomechanical pulping and brightening of blue-stained chips. 2007. Hu, T.; Johal, S.; Yuen, B.; Williams, T.; Osmond, D.; Watson, P.A. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC. Mountain Pine Beetle Initiative Working Paper 2007-10. 27 p.
Issued by: Pacific Forestry Centre
Catalog ID: 26813
Availability: PDF (download)
Thermomechanical and chemithermomechanical pulps were prepared and tested from blue-stained and sound lodgepole pine samples. Blue-stained samples had higher amounts of fine and pin chip content and slightly less basic chip density than did the sound samples. There was no well-defined relationship between refining energy, fibre properties, strength properties, or optical properties of thermomechanical and chemithermomechanical pulps prepared from blue-stained and sound lodgepole pine chips. Blue-stained pine thermomechanical pulping responded poorly to sodium hydrosulfite bleaching, but responded to alkaline hydrogen peroxide bleaching as well as the unstained pine thermomechanical pulping did at high peroxide charges. The light stability of the peroxide-bleached, blue-stained thermomechanically pulps was identical to that of the peroxide-bleached, unstained thermomechanical pulps. Blue-stained pine chemithermomechanical pulps also responded poorly to sodium hydrosulfite bleaching, but responded to alkaline hydrogen peroxide bleaching better than did the unstained pine chemithermomechanical pulps. The light stability of the peroxide-bleached, blue-stained chemithermomechanical pulps was also slightly higher than that of the peroxide-bleached, unstained control. The hydrosulfite-bleached, blue-stained thermomechanical or chemithermomechanical pulps had the advantage of low yellowness (CIE b*) over the bleached, unstained pulp.