Productive test of a newly drying technology of veneer： intermittent-contact drying of veneer with flexible screen belt

A newly drying technology, intermittent-contact drying of veneer with flexible screen belt (ICD-fbs), was invented and used in poplar veneer drying. Productive test was carried out for validating the practical use of this drying method. The test result shows that to dispose flexible screen belts on the two sides of hot board could help steam discharge remarkably. The veneer dried using ICD-fsb method had smooth and level surface, less deformation and warping, even moisture content, and high utilization rate. The time for opening hot board to discharge steam,which, early or late, is a key to obtain good drying result, was determined at the time when the core‘s temperature of veneer reaches 100℃ (vaporization). Using ICD-fsb method, the shrinking rates in tangent of veneer were from 1.90% to 2.26% for veneer of 0.4 mm in thickness,2.49% to 4.50% for veneer of 1 mm in thickness and 1.34% to 3.30% for veneer of 1.7 mm in thickness, which are much lower than the results obtained by other drying methods. The method of ICD-fsb offers a reliable technological guarantee for solving the deformation problem of veneer drying, especially the deformation of wood from quick-growing plantation.

Productive test of a newly drying technology of veneer: intermittent-contact drying of veneer with flexible screen belt

A newly drying technology, intermittent-contact drying of veneer with flexible screen belt (lCD-fbs), was invented and used in poplar veneer drying. Productive test was carried out for validating the practical use of this drying method. The test result shows that to dispose flexible screen belts on the two sides of hot board could help steam discharge remarkably. The veneer dried using ICD-fsb method had smooth and level surface, less deformation and warping, even moisture content, and high utilization rate. The time for opening hot board to discharge steam, which, early or late, is a key to obtain good dyring result, was determined at the time when the core's temperature of veneer reaches 100°C (vaporization). Using ICD-fsb method, the shrinking rates in tangent of veneer were from 1.90% to 2.26% for veneer of 0.4 mm in thickness, 2.49% to 4.50% for veneer of 1 mm in thickness and 1.34% to 3.30% for veneer of 1.7 mm in thickness, which are much lower than the results obtained by other drying methods. The method of ICD-fsb offers a reliable technological guarantee for solving the deformation problem of veneer drying, especially the deformation of wood from quick-growing plantation. Foundtion item: This work is supported by “Xing Huo” Program of the Ministry of Agriculture, P. R. China. Biography: HUA Jun (1959-), male, professor in the College of Mechanical and Electrical Engineering. Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Chai Ruihai