| Popis: |
Physical and mechanical properties of three layer cement bonded board produced from flakes of Polyalthia longifolia and kraft paper were assessed. The boards were produced with three different material blends and mixing ratio, material blends include pure paper, pure flakes (one layer) and paper/flakes(3-layer). The 3-layer boards were produced by using flakes to form the core and paper slurry for the face and back. Water absorption (WA), thickness swelling (TS), linear expansion (LE), and mechanical test; modulus of elasticity (MOE) and modulus of rupture (MOR) tests were conducted. The board formation was based on a mixing ratio of 1:1, 2:1, 3:1 i.e. cement to material blending proportion. The mean value for WA, TS, LE ranged from 29.23±2.18 % - 55.92±2.50 %, 1.93±1.62% - 5.74±2.61 %, 0.27±0.16 % - 0.51±0.19 % for PAPER+FLAKES, 25.86±2.18% - 58.69±4.90 %, 1.74±1.32 % - 4.52±2.05 %, 0.35±0.41 % - 0.65±0.48 % for PURE FLAKES while 38.82±6.80 % -61.06±3.67 %, 0.51±0.63 % - 3.53±1.80 %, 0.36±0.33% - 3.96±6.42% were recorded for PURE PAPER respectively. The mean values of MOE and MOR ranged from 249.46±0.71 N/mm2 -727.26±2.82 N/mm2 and 0.09±0.18 N/mm2 - 0.26±0.11 N/mm2 respectively. The physical property test showed that the inclusion of paper slurry forming the face and back with flake as the core (3-layer) influences the surface quality of the boards produced while the mechanical tests showed that the addition of flakes improves the strength properties. |
