Production of Thermal Wall Insulation from Water Hyacinth (Eichhornia cressipes) and Cogon Grass (Imperata cylindrica)

Water hyacinth (E. cressipes), and Cogon Grass (Imperata cylindrica) fibers have long been used for different purposes such as paper, crafts, and insulation because of their abundances as pest plants and the fibers' characteristics (Bhuvaneshwari, 2016; Kassim et al., 2015). Previous studies have investigated and assessed water hyacinth regarding thermal insulation. However, cogon grass has not yet been studied regarding its insulating characteristics. Both plants may be used as eco-friendly materials in replacement of the synthetic fibers used in thermal insulation. In this study, the insulation panels were made in different compositions to test effectivity among the different samples in terms of insulating heat and compatibility among the fibers. Five compositions of panels were made: 100% hyacinth only, 75% hyacinth 25% cogon, 50% hyacinth 50% cogon, 25% hyacinth 75% cogon and 100% cogon. Fibers were obtained by boiling, trimming, and blending the stalks and leaf blades. The panel boards were formed and shaped according to the stipulated ratios in metal trays separated by sheets of aluminum foil. The heat test was conducted under the sun from 11:00 am to 2:00 pm to simulate the heat from the peak of the day's heat on thermal insulation. A heat test, density test, ANOVA, and T-test were conducted. Since the F_comp value was greater than the critical value, ANOVA results showed that panels with 25% cogon and 50% cogon compositions may have been effective in insulating the heat surrounding them and all were comparatively in line with standard thermal insulation may it be synthetic or hyacinth insulation from other studies. The comparison of hyacinth insulation and all the other panels utilized a two-way t-test, the 50:50 hyacinth-cogon composite was still the best performing panel in insulating heat due to the balance of qualities possessed by cogon and hyacinth fibers. Although this paper shows the compatibility of these natural components as thermal insulation, there may still be many characteristics regarding insulation to be tackled and improved upon. Further studies should be done on different types of local pest plants for thermal insulation testing and prototype development.