Varying weight percentages of pineapple leaf fiber were added to phenolformaldehyde (PF) in order to generate a composite material. Using the transient plane source (TPS) technique, the thermal conductivities of the varying weight percentage composites were studied. It was found that increasing weight % pineapple leaf fiber resulted in decreasing thermal conductivity and diffusivity of the composites. The experimental results are compared to results produced by two models (the Rayleigh-Maxwell and ...