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

The modulus of elasticity MOE of teak plywood thermal treatment of control was 12,734.54± 2,246.33 MPa, the thermal treatment was reduced MOE on high different level of temperature as to compared control with at 180 °C, 200°C, 220 °C, and 240 °C the MOE. According to DEL MENEZZI et al. (2017) studied that the teak LVL of MOE in different volume of spread was 8,469.8 MPa, 8,872.4 MPa, and 9,132.6 MPa to lower than this study. SOUKPHAXAY et al. (2021) studied that the MOE of teak LVL was lowest in 2,609.97 MPa. DEL MENEZZI et al. (2017) and SOUKPHAXAY et al. (2021) confirm that the MOE of LVL was lower than teak thermal treatment of plywood. The different level of temperature thermal treatment decreased MOE of teak thermal treatment plywood. Based on multiple comparisons by One-way ANOVA analysis showed that the results of PF groups to compared a control with 180°C, 200°C, 220°C, and 240°C were high significantly different (sig<0.05), to compared 180°C with 200°C was not significantly different (sig>0.05), to compared 180°C with 220°C and 240°C were high significantly different (sig<0.05), to compared 200°C with 220°C and 240°C were high significantly different (sig<0.05), and to compared 220°C with 240°C was not significantly different (sig>0.05). The multiple comparisons of times length thermal on different times of two plywood adhesives. To compared a control sample with 4 min, 8 min and 12 min were high significant different (sig<0.05), and its MOE were high than other times thermal treatment. Comparing 4 min with 8 min and 12 min was not significantly different (sig>0.05) and to compared 8 min with 12 min was not significantly different (sig>0.05). The shearing strength value of teak plywood thermal treatment of control in PF was 13.55±2.97 MPa. This study was similar Nautiyal (2015) studied that shear strength of Melia composita and Populus deltoides in 5 ply, to applied PF condensation and result showed that the shear strength in dry condition ranged from 13.82 to 14.7 MPa, and 9.4 to 11.57 MPa in wet condition. According to International Thermowood Association (2003) reported that the higher-temperature treatments (at 230 °C for 4 hours) the strength properties were reduced in radial tests from 1 to 25%. This study was similar with theory of International Thermowood Association (2003). But this study shear strength was higher Bekhta et al. (2016) in 8.39 MPa because this study used PF glue spread more 150 g/m 2 . The shearing strength was depended on volume of glue spread in layer plywood. One-way ANOVA analysis showed that the multiple comparison of significant different for PF. The PF group, to compared control sample with at 180 °C, 200 °C, 240 °C were no significant different (P>0.05), to compared control sample with at 220 °C was high significant different (P<0.05), to compared at 180 °C with at 200 °C was no significant different (P>0.05), to compared 180°C with at 220°C, and 240°C were significant different (P<0.05), to compared at 200°C with at 220°C was high significant different (P<0.05), to compared at 200°C with at 240°C was not significant (P> 0.05), and to compared at 220°C with at 240°C was high significant different (P<0.05). The length of time thermal treatment on 4, 8, and 12 min was not significant different. The hardness of this study was showed in Table 1, and 2 show the average and standard deviation of teak plywood thermal treatment. The control was 22.09±6.35 MPa the percentage of hardness compared with control showed that the hardness increased at 200°C, and 240°C in 11.18 %, and 0.95 (PF) respectively. In contrast, the different level of temperature at 180°C, 220°C the hardness decreased in 14.21 %, 0.22 % (PF) respectively. The length of time illustrated that the thermal treatment on 4, 8, and 12 min was a little fluctuation. According to Lengowski et al. (2021) confirm that teak thermal treatment was significant declines of hardness occurred in the longitudinal and tangential section. Pelit et al. (2015) confirm that the higher in Eastern beech samples (36.30 N/mm 2 ) than in Scots pine samples (27.27 N/mm 2 ), and the hardness was increased as treatment temperature increases. Base on International Thermowood Association (2003) recorded that the thermo-solid wood treatment at 180°C to 240°C the hardness increased as the treatment temperature increases, the Brinell hardness was highly dependent on the density as bout 17.64 %. This study was similar with Lengowski et al. (2021) at 180°C, 220°C (PF), and similar with Pelit et al. (2015) and International Thermowood Association (2003) at 200°C, and 240°C (PF). The multiple comparison analysis of the PF group, to compared control with at 180°C and 200°C were significant different (P<0.05), to compared control with at 220°C and 240°C were no significant different (P>0.05). The significant point is that compared at 180°C with at 220°C 220°C and 240°C were high significant different (P<0.05), but to compared at 200 °C with at 220°C, 240°C were no significant different (P>0.05), and to compared at 220 °C with at 240°C was no significant different (P>0.05). The length of time thermal treatment on 4, 8, and 12 min. To compared control with 4 min, 8 min and 12 min were no significant different (P>0.05), but to compared 4 min with 8 min was high significant (P<0.05), to compared 4 min with 12 min was no significant different (P>0.05), and to compared 8 min with 12 min was significant different (P<0.05). PF multiple regression model (Eq 5X) considered as high (R 2 =0.83) MOR(PF)=0+0.3103*T+(-0.1603) *t (Eq 5x) 1 Year 2022 8 © 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