Effect of coir fiber reinforcement in PLA on the heat transfer characteristics – numerical simulations

Abstract

The use of natural materials for thermal insulation over synthetic materials is on the rise due to their environmental friendliness, ease of availability, and cost-effectiveness. Additionally, the utilization of agro-waste-based materials in value-added applications promotes circular economy. The current study examines coir fiber and its insulating capability. Short coir fiber-reinforced Polylactic acid (PLA) is evaluated, with the fiber volume fraction ranging from 0 to 38%, to assess its suitability for thermal insulation applications through numerical simulations. Using commercial finite element-based software, the effective thermal conductivity of the natural fiber composite is calculated, which is the key property for insulation applications. A steady-state heat conduction analysis is performed on the composites with a periodic and uniformly oriented arrangement of coir fibers. Numerical results are validated using existing theoretical and empirical methods, such as the Parallel model, Halpin-Tsai, Lewis and Nielsen model. Initial investigations are done using simple geometries, revealing the effectiveness of incorporating coir into an environmentally friendly polymer matrix, PLA. The numerical results show that the effective thermal conductivity decreases with an increasing fiber volume fraction. This research concludes that adding coir fiber to the PLA matrix improves its insulation capabilities.