Thermal Conductivity of Different Grain Sizes of Top Bond, Clay and Starch Bonded NIPA Palm Wood Composite Products

Abstract

The study examines the thermal conductivity of five different grain sizes of Nipa palm seed bonded in a varying proportions with 10% to 50 %of three separate binders. These binders are; Top bond, Starch and Clay. The samples grain sizes of 300 µm, 425 µm, 500 µm, 850 µm and 1000 µm were sieved out of Nipa palm Seed and fabricated to an appropriate disc shape using a modified hydraulic press. The modified Lee's disc apparatus incorporated with temperature data logger was used to determine the thermal conductivities of the samples. The results showed that for any particular grain size, increasing the binder content resulted to decrease in the thermal conductivity of the samples. The thermal conductivity values obtained for the samples fall within the range 0.094 - 0.667 Wm^-1K^-1. This range lies within the thermal conductivity values of common wood materials. The grain sizes that is best insulating due to its lower thermal conductivity are 850 µm and 1000 µm and were all top bond samples. In addition, the sample with 1000 µm grain size and 50 % top bond as a binder pose to be the best among the samples considered. With this property and further improvement, Nipa palm plant can be harnessed for possible usage as industrial insulating devices and thermal insulators.