Application of the steaming step during kiln drying of lumber of two tropical species with high growth stress presence

Abstract

The relaxation of growth stress in trees from plantation forests of tropical areas is manifested in the quality of wood after the sawing and the relaxation of drying stress is expressed during the drying process, producing low wood quality. The present study aims to evaluate the lumber quality in logs by heating and steaming application before sawing as pretreatment to reduce growth stress and the application of steaming step during drying of Dipteryx panamensis (almendro) and Hieronyma alchorneoides (pilón) wood. The results showed that the variation of moisture content and drying rate concerning drying time in wood from logs steamed before or during drying led to a quick increase in the drying rate and a decrease in the moisture content. The steaming application to the logs or during drying decreased the incidence and magnitude of drying defects and increased the quality of dried lumber, especially bow, split, crook, and check defects.

Keywords:

• Drying defects
• tropical wood
• log treatment
• drying improvement

Additional information

Funding

The authors wish to thank the Vicerrectoría de Investigación y Extensión, Instituto Tecnológico de Costa Rica (ITCR, Cartago, Costa Rica) for the financial support of the project. We would also like to thank the company Cinco Ceibas Rainforest Reserve and Adventure Park for providing material and financial support for this research.