| dc.description.abstract | Urea-formaldehyde adhesive is the most common type of adhesive used in the manufacture of plywood and other panel products. The presence of formaldehyde emissions (FE) can cause pollution in the air and negatively affect the health problems, especially if used indoors. Therefore, adhesive modifications are needed to reduce the FE. The common formaldehyde to urea (F/U) molar ratio used in industry ranges from 1.0-1.5. In order to reduce the amount of FE, this study further reduced the FU molar ratio of UF adhesive to 0.8. The objective of this study was to investigate the influence different amount of glue spreads of 0.8 F/U molar ratio UF adhesive on the properties of plywood. Three glue spreads were applied in triplicate namely 160 g/m2, 180 g/m2, 200 g/m2. The physical, mechanical, chemical, thermal, and the FE were examined according to the Japanese Agricultural Standard (JAS No. 233) for plywood. The 0.8 F/U mole ratio UF adhesive had a solid content of 58.79%, a viscosity of 67.11 mPa.s, a pH of 8.2, and a gelation time of 282.0 seconds. In general, the plywood had a density of 0,34±0,01 g/cm3, moisture content ranging from 7.48 - 9.52%, delamination 100%, MOR and MOE of 36.94 MPa and 4151.47 MPa, and tensile shear strength of 0.44 – 1.10 MPa. The glue spread of 200g/m2 showed the most superior properties. The test results show that the plywood in this study has met the minimum requirement of the JAS No. 233 for Plywood, but it is only intended for interior use. | en_US |
