Influence of Kiln Venting on Brown Stain in Pinus Radiata Sapwood

Abstract

This study assesses the influence of a closed drying environment on kiln brown stain in Pinus radiata sapwood. Three sets of matched timber samples (N = 50) were dried at low temperature (50°C), one without and two with kiln venting. Statistical analysis showed that the closed drying environment produced no significant change in the lightness (L∗) of kiln brown stain. Relative to the samples dried in the vented process, there was a small but statistically significant increase in the green color (Δa∗ ≈ − 1.7) for both the stained area and the unstained early-wood of the samples dried in the non-vented kiln.

Keywords:

• Closed-kiln drying
• Heat pump dryer
• Timber color

ACKNOWLEDGEMENT

The authors thank the New Zealand Foundation for Research Science and Technology for supporting the work presented in this article through contract UOOX0212 awarded to the University of Otago.

Notes

∗Initial moisture content was determined for bulk, not separately for each series.