Your search resulted in 8 documents.
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 3: Full penetration of the refractory sapwood of white cypress
2000 - IRG/WP 00-40167
The heartwood of white cypress, Callitris glaucophylla, is renowned for its termite resistance and durability against decay. The sapwood, which can represent up to 30% of log volume, is non-durable and refractory to conventional preservative treatment. Previous work ascribes the lack of permeability to oily deposits within tracheids and ray cells. Environmental scanning electron microscopy was use...
M J Kennedy, L M Stephens, M A Powell
The use of pressure cycling to improve heartwood penetration in Pinus radiata (D. Don)
1995 - IRG/WP 95-40050
This study investigates the effect of cycling pressure on the treatability of radiata pine heartwood. The results indicate that liquid penetration into the heartwood is affected by the preconditioning method used and pressure treatment time. There is no significant improvement in the penetration of Pinus radiata (D. Don) heartwood when a cycling or pulsation process is used....
P R S Cobham, P Vinden
Options for accelerated boron treatment: A practical review of alternatives
1985 - IRG/WP 3329
Boron wood preservatives are almost exclusively applied by momentary immersion and block diffusion storage. Alternative techniques are described which can be used to accelerate boron treatment. Diffusion coefficients have been derived to define the acceleration of diffusion with increasing temperature. Schedules are described for pressure impregnation of green timber, involving steam conditioning,...
P Vinden, T Fenton, K Nasheri
Preservative treatment of Pinus elliottii
1987 - IRG/WP 3435
The treatment of Pinus elliottii with copper-chrome-arsenic preservative by four alternative seasoning and treatment methods is investigated. Steam conditioning followed by either alternating pressure method (APM) or 'Q' treatment resulted in inadequate preservative penetration. Air drying or high temperature drying followed by the Bethell process resulted in a high standard of t...
P Vinden, L Carter
Microwave conditioning of Pinus radiata D. Don for preservative treatment
2000 - IRG/WP 00-40182
This paper reviews the effect of pressure steam conditioning on the permeability and treatability of green radiata pine heartwood and the potential for substituting microwave conditioning for steaming. The penetration of liquids into radiata pine occurs mainly in the radial tissue. The permeability of green radiata pine improves following steam conditioning by blowing out the soft radial tissue. T...
P Vinden, G Torgovnikov, J Romero
Possibilities of improving the oscillating pressure method
1991 - IRG/WP 3668
Studies on the dynamics of pressure changes in wood during impregnation revealed no significant effect of fast pressure changes for green spruce as used by OPM (IRG/WP/3615). The following experiments were carried out on several hundreds of spruce palisades to examine the modification of single procedure parameters of common use OPM and to record the effects on the impregnation result with the aim...
S Goetsch, R-D Peek
Steam/hold/APM boron treatment - Treatability trials with green gauged radiata pine
1987 - IRG/WP 3439
Freshly sawn 100 x 50 mm radiata pine was green gauged, steam conditioned and preservative treated with a mixture of borax and boric acid using a modified Alternating Pressure Method (APM) treatment schedule. A 12 hour holding period between steam conditioning and treatment resulted in the necessary moisture loss and moisture re-distribution to facilitate treatment to NZ Timber Preservation Author...
Development of a commercial-scale CCA chemical sludge recycling system
1993 - IRG/WP 93-50001-19
The occurrence of fixation reactions in Copper Chromium Arsenate (CCA) treatment solutions is increased where the treatment of unseasoned and partially seasoned timbers in hot climates occurs. The by-products of the fixation reactions are predominantly insoluble chromium arsenate compounds, commonly referred to as CCA sludge. Historically, this material has been disposed of into toxic waste landfi...
A J B Butler