Redistribution of moisture in pre-dried pinewood using microwave power : a preliminary study

• Commonly, during air-circulation kiln drying moisture gradients within wood cross-sections are developed, i.e. thesurfaces become drier than the interior. To minimize these gradients a conditioning step subsequent to the drying isneeded. The aim with this study was to investigate the possibility to use microwave power for redistribution ofmoisture within pinewood planks after air-circulation kiln drying to the average moisture content 0,14. Twodimensions of pinewood were tested; thickness 50 and 63 mm, in two different plants, generating 5 and 12 kWmicrowave power respectively. Results show that microwave energy give rise to a fast and advantageous moistureredistribution i.e. equalization of moisture content within the wood. The higher microwave power density the fasterheating and moisture equalization in these wood dimensions. Required time for heating and redistribution ofmoisture was found to be as short as 3 minutes at the power density 500 kW/m3. In addition, split-tests indicatedecreased or almost no gap in the investigated specimens.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik -- Biomaterial (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology -- Bio Materials (hsv//eng)

Keyword

Wood Physics

Träfysik

Publication and Content Type

ref (subject category)

kon (subject category)