Kiln drying for bamboo culm parts of the species Bambusa stenostachya, Dendrocalamus asper and Thyrsostachys siamensis

Abstract

In South Vietnam Bambusa stenostachya, Dendrocalamus asper and Thyrsostachys siamensis are the major commercial species. Their culms are used for housing and for manufacturing of furniture to export. Our previous study resulted that the kiln drying of 1.4 m culm parts of the bamboos can be conducted successfully using proper schedules defining temperature and relative humidity. In this paper, the effective schedules were further investigated for longer culm parts treated with boron. Culm parts with 2.0 and 2.2 m length after pressure treatment were dried in industrial kilns using three schedules with mild, severe and highly severe drying intensity. The moisture loss, drying time and drying defects were determined. The species T. siamensis is the easiest to dry. It takes 8 days for culm parts to reach 10 % starting from an initial moisture content above 120 % with a highly severe drying schedule. B. stenostachya dries moderately fast in 10 days using a severe drying schedule. D. asper is the most difficult species to dry and requires a mild schedule. It is prone to checking and splitting and needs 13 days of drying.