Effect of post treatment temperature and humidity conditions on fixation performance of CCA-C treated red pine and southern pine

Abstract

Rates of fixation in chromated copper arsenate (CCA-C) treated red pine (Pinus resinosa Ait.) and southern pine (Pinus spp) sapwood specimens using retention of 1.5, 2.0, 6.4 kg·m⁻³ are compared at temperature (T) ranging from 70°C to 50°C and 5 different relative humidity (RH) conditions. The samples were investigated using the expressate method to follow chromium fixation. Red pine fixes faster than southern pine under all 11 post treatment schedules. The fixation rates for both species are not significantly different while the blocks were fixed under 6 fixation/drying schedules that differed only in the order of T/RH conditions applied. The rate of fixation of all samples in any fixation stage were reduced when the blocks were fixed under lower humidity conditions in spite of no change in chamber temperature. Some of this influence can be attributed to the effect of humidity on heat transfer into the wood and cooling of the wood surface.

Keywords

CCA-c / Fixation / Post treatment / Temperature / Relative humidity / Red pine / Southern pine

References

[1] Alexander D.L., Ung T.Y., Cooper P.A. Effects of temperature and humidity on CCA-C fixation in pine samples Wood Protection, 1993, 2(2): 29-45.

[2] American Wood Preservers’ Association The AWPA Book of Standards, 1997 Woodstock, MD: AWPA

[3] Anderson D.G. The accelerated fixation of chromium copper preservative treated wood Proc. Can. Wood Preserv. Assoc., 1989, 10: 75-110.

[4] Avramidis S., Ruddick J.N.R. Effect of temperature and moisture on CCA fixation Holz-als, Rohund Werksoff, 1989, 7(8): 328-328.

[5] Boone R.S., Winandy J.E. Effects of redying schedules on preservative fixation and strength of CCA-treated lumber Forest Prod. J., 1995, 45(9): 65-73.

[6] Chen, J.M., Kaldas, M., Ung, T.Y., Cooper, P.A. 1994. Heat transfer and wood moisture effects in moderate temperature fixation of CCA treated wood. IRG/WP/40022, 13pp

[7] Conradie W.E., Pizzi A. Progressive heat inactivation of CCA biological performance Proc. Amer. Wood Preserv Assoc., 1987, 83: 32-49.

[8] Cooper P. A., Alexander D.L., Ung Y.T. What is chemical fixation? chromium-containing waterborne wood preservatives, fixation and environmental issues, 1993 Madison, Wis: Forest Prod Soc 7-13.

[9] Cooper P.A., Ung T.Y. A simple quantitative measure of CCA fixation Forest Prod. J., 1993, 43(5): 19-20.

[10] Cooper P.A., Ung T.Y., Leonov E. Fixation of CCA-C reated pine at moderate temperature Proc. Can Wood Preserv. Assoc., 1989, 10: 111-118.

[11] Kaldas M., Cooper P. A. Effect of wood moisture content on rate of fixation and leachability of CCA-treated red pine Forest Prod. J., 1996, 46(10): 67-71.

[12] Kartal S. Nami. 1999. The leachability, biological resistance and mechanical properties of wood treated with CCA and CCB preservatives. 1999, IRG/WP/99-30207

[13] Lee A.W.C., Grafton J.C., Tainter F.H. Effect of rapid redrying shortly after treatment on leachability of CCA-treated southern pine Forest Prod. J., 1993, 43(2): 37-40.

[14] Lebow S.T., Morrell J.J., Milota M.R. Western wood species treated with chromium copper arsenic: Effect of moisture content Forest Prod. J., 1996, 46(2): 68-70.

[15] Micklewright J.T. Wood preservation statistics 1991. A report to the wood preserving industry in the USA, 1993 Woodstock. MD: American Wood Preservers’ Assoc

[16] Smith P.M., Sinclair S.A. The professional contract/remodeler: Marker research for CCA-treated lumber products Forest Prod. J., 1990, 40(6): 8-14.

[17] Ung T.Y., Cooper P.A. Feasibility of drying CCA-treated red pine poles during fixation Forest Prod., 1996, 46(6): 46-5.