1. Wood Research Centre 2 Department of Wood and Forest Sciences, Laval University, Quebec (Qc), Canada G1K 7P4 Potential of High-Temperature Drying for the Production of Value-Added Products Yves FORTIN* and Aziz LAGHDIR Slovakia European Union Quebec

2. Wood Research Centre Aim of work and methods 3 To study the potential of high temperature drying for the manufacturing of value-added products from wood species traditionally used for construction lumber:  Development of drying programs and strategies  Evaluation of drying time, quality of the dried products and energy consumption

3. Wood Research Centre Aim of work and methods 3 Wood species and experimental procedure  SpeciesDimensionsTop loadingDrying process  (kN/m2)  Black spruce (Picea mariana) 50 x 75 x 2400 mm 1.2 & 9.8HTD  White spruce (Picea glauca)50 x 100 x 2400 mm 7.2HTD  Balsam fir (Abies balsamea)50 x 100 x 2400 mm 7.2 CTD/HTD ; HTD  Tamarack (Larix laricina)32 x 100 x 2400 mm 7.5 CTD ; ETD ; HTD  Trembling aspen (Populus  tremuloides)50 x 100 x 2400 mm 7.2 CTD/HTD ; HTD

4. Wood Research Centre Aim of work and methods 3 Experimental 2.5 m3 capacity kiln

5. Wood Research Centre Aim of work and methods 3 Typical HT drying schedule

6. Wood Research Centre Results 4 Comparison of drying time

7. Wood Research Centre Results 4 Comparison of drying time

8. Wood Research Centre Results 4 Comparison of drying time

9. Wood Research Centre Results 4 Warp and grade fall-down

10. Wood Research Centre Results 4 Warp and grade fall-down

11. Wood Research Centre Results 4 Effect of sinker heartwood on the final moisture content (FMC) distribution

12. Wood Research Centre Results 4 Total shrinkage following kiln drying  1 50 x 75 x 2400 mm black spruce kiln dried to 10% MC  2 50 x 100 x 2400 mm plantation white spruce kiln dried to 10%

13. Wood Research Centre Results 4 Energy consumption at the kiln

14. Wood Research Centre HTD has a great potential for the drying of value-added products; HTD saves time, electrical energy and can help to control drying defects for warp prone species; Conclusions

15. Wood Research Centre HTD must be combined with CTD for species containing impermeable sinker heartwood; A proper strategy of HTD must provide for the use of top-load restraint, presteaming treatment, long equalizing period, conditioning, and a slightly increased green dimension in thickness. Conclusions The authors thank Mrs. Gordon Duplain, Bruno Girard, Abdelkarim Ben Mhenni, and Javier Chung, former graduate students, for their contribution to this paper.