PENGARUH PENGERINGAN VAKUM TERHADAP KEKUATAN MEKANIK LAPISAN KAYU TERAS DAN GUBAL DARI KAYU KUMEA BATU

Abstract

The purpose of this study was to determine the effect of vacuum pressure change and temperature on wood
vacuum drying processes, on the mechanical strength of the core layer and sapwood of kumea stone wood (manilkarra
merrilliana, H.J.L). The method of achievement is to vary the vacuum pressure of 30 kPa, 65 kPa and 100 kPa, with
variations in drying chamber temperature of 50oC, 65oC and 80oC. The dimensions of wood are 25 cm x 2.5 cm x 1.0
cm, both heaters as a convection heat source are installed at the bottom of the wood in the drying chamber. The test was
carried out for 200 minutes and every 20 minutes the wood mass was measured. Observation results in the drying
chamber, obtained a degree of dryness that varies from wood. Then testing the mechanical strength of wood at the
Universal Testing Machine was carried out. The test results were analyzed, so that the flexural strength (MoE) and
fracture strength (MoR) of wood were obtained. Testing at a vacuum pressure of 30 kPa and a temperature of 80oC
resulted in the greatest flexural strength (MoE) for the core and sap layers, namely 976.73 kg / cm2 and 883.71 kg / cm2,
while the greatest fracture strength (MoR) for the porch and sapwood layers was obtained on testing vacuum pressure 65
kPa and tempur 80oC at 17.87 kg / cm2 and 15.91 kg / cm2. To produce good flexural strength (MoE) and fracture
strength (MoR), vacuum drying of the core layer and sapwood of kumea stone (manilkarra merrilliana, H.J.L) must be
carried out at a vacuum pressure of 30 kPa and a temperature of 80oC.