Global Journal of Science Frontier Research, G: Bio-Tech & Genetics, Volume 22 Issue 2

plywood has 10 mm of average, time for pressing at 10 min for 130 °C. The press loading is 2.5 MPa/mm 2 . A. Density testing: According to the Standard (AS/ANZ 2098.7, 2012), the specimen should be cut into 10x25x50 mm (30 specimens), formula calculation as Eq1. Density Mass Volume (1) Where: Density is mass divided by volume of a specimen (g/cm 3 ), Mass is the weight of a specimen (g), Volume is the multiple of thickness, width, and the length of a specimen (cm 3 ). B. Water Resistant or Absorption Testing: method for testing was using ASTM D 3502-76 as the method recorded by Somwang (1995). Method testing specimen was placed in a conditioning chamber for 24 h in the temperature at 50±2°C. Next, Specimen should be soak in the distilled water at 25±2 °C in for 24 hours, then using dry cloth to support for taking of water from the surface and immediately weigh it and recording data. Water absorption (WA) calculation as Eq 2. WA = W 2 −W 1 W 1 x100 (2) Where: WA water absorption (%), W 1 Weight of a specimen before soaking distilled water (g), W2 weight of a specimen after soaking distilled water (g) C. Thickness swelling: the method was following up point B mention above, thickness was measuring by digital caliper and swelling changes as calculated in Eq 3. Swelling (%) = (T 2 −T 1 ) T 1 x100 (3) Where: T 1 thickness before soaking in distilled water and T 2 Thickness after soaking distilled water. MOR and MOE were testing the same specimen which it’s dimension of 10x20x300 mm accordance with D1037-12 for test specimen shall be less than 12 mm of thickness and speed loading rate is 3mm/min. formula of rate as calculation in the Eq 4. = 3 2 2 (Eq4) Where: P max =maximum load (N), L= Length of span (mm), b= width of specimen measured in dry condition (mm), d=thickness (depth) of specimen measured dry condition (mm) MOE was calculating by formula as Eq 5. = 3 4 3 ∆ ∆ (Eq 5) Where: L= Length of span (mm), d=thickness (depth) of specimen measured dry condition (mm), b= width of specimen measured in dry condition (mm), ∆ ∆ =slope of the straight-line portion of the load deflection curve (N/mm) The shearing strength was following D143. The load applied continuously throughout the test at a uniform rate of motion of the movable crosshead of the testing machine of 0.6 mm/min, the calculation as Eq 6. ℎ = (6) Where: d=thickness (depth) of specimen measured dry condition (mm), b= width of specimen measured in dry condition (mm), and P max =maximum load (N) The diameter of head pressor is 10 mm, and load applied continuously throughout the test at a uniform rate of motion of the movable crosshead of testing of 1.3 mm/min (ASTM, 20112). The calculation hardness as Eq 7. ( ) = 2 ¶ ℎ (5) Where: P=loading selected is to be in calculation (N), r=radian of penetrating ball (mm), and h=depth of penetrating in specimen (mm) Data Analysis: All properties of teak plywood analysis conducted by One-way ANOVA table of statistic in relativity 95 %. Whole study was use multiple comparison. If Significant (sig) differences start from sig equated 0.05 (p=0.05) and high significant differences of three techniques and wood machineries in recovery is 0.00 (p=0.00). The multiple regression model analyzed only mechanical property. IV. R esult and D iscussion Table 1 showed that average and standard deviation of physical and mechanical property of thermo-treatment teak plywood. The length of time was showed in Table 2, the physical property investigated density, thickness swelling and water absorption. The mechanical property investigated MOR, MOE, Shearing, and hardness. The density was highest (0.705±0.04 g/cm 3 ) which it was thermo-treatment in different level of temperature for percentage of density decreased in 3.12% at 180°C, 5.39 % at 200 °C, 3.12% at 220 °C, and 3.40 % at 240 °C compared with control CL. This study the age of teak plywood 18 year old to less than May (2003) study teak age was 20 year old in 0.26 g/cm 3 .This study to compared with Cuccui et al. (2017) treated solid wood at temperature of 180°C for 5 hours, the PF density of this study was higher 12.88% in condition of humidity at 0%, 11.27% in condition of humidity at 30 %, and 9.80 % in condition of humidity at 60%. One-way ANOVA analysis to compared between significant different from each temperature level, result showed that PF plywood product compared between control with thermal at 180-240°C was high significant different P <0.05. While compared temperature between 180°C with 200-240°C was only 1 Year 2022 79 © 2022 Global Journals Global Journal of Science Frontier Research Volume XXII Issue ersion I VII ( G ) Physical and Mechanical Properties of Teak (Tectona Grandis L.Fil.) Thermo-Plywood from Plantations in Lao P.D.R