| Summary: | ABSTRACT
The State Forest Enterprise (Perum Perhutani) made a lot of Pinus merkussi plantation, but utilization of its wood was only limited to chopstick, tooth pick, match, paper and laminated board.. Utilization of the wood for lumber was still very little. Facing this situation, the author wanted to try to investigate drying properties of Pinus nieriarsii lumber, 2, 3 and 3 cm thick at dry kiln since maximum benefit will only be obtained if lumber was dried very soon. The properties were drying speed, shrinkage and drying defects, e.g. end check, bow and crook.
Material used were Pinus merkussi Jungh. et de Vriese lumber, 2, 3 and 4 cm thick which were cut green from their log using the same cutting pattern. The width and the length of the lumber were all the same, e.g. 20 cm and 2,00 m respectively. The lumber were piled horizontally using stickers between each pile and dried in a dry kiln (dry kiln was operated during the day only). Kiln samples, 60 cm long each, were used to check moisture content of the wood during drying. These samples were weighed every day during drying. Drying was terminated after kiln samples reach average moisture content of 10%. End check, bow, crook and shrinkage from green to kiln dry were all then determined.
Results showed that there is no significant difference in drying speed among the three thicknesses of the lumber from green to average moisture content of 9-10%. It took 13 to 15 days to reach the moisture content with effetive operated kiln drying lime of 92 to 106,3 hours. Average shrinkage from green to kiln dry was 2,42%, 2,40% and 2,09% for 2, 3 and 4 cm thick lumber respectively. There was no significant difference in shrinkage among the three thicknesses. Shrinkage decreased from bark to pith (tangential toward radial cross section), but then increased near the pith. End check observed was 2 to 4,5% with average length of 2,25 to 9,54 cm. Bow and crook were found at almost of the lumber. Average bowing was 0,4 to 0,56 cm, while crook was 0,24 to 0,50 cm.
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