Environmentally friendly materials have become an important topic in practical research due to their importance to people's lives and the preservation of the environment. The use of wood plastics is of utmost importance in this field, as it is possible to obtain materials with properties that combine the strength of polymers with the properties of wood. The goal of the current study is to enhance wood-plastic composites by incorporating high-density polyethylene (HDPE), Polycarbonate (PC), and teak wood to improve their hardness and physical properties. An injection molding machine is used to prepare the samples. The Taguchi method is adopted to test the experimental design and three independent variables including teak wood particle size, weight%, and PC content. Samples are tested for water absorption, swelling thickness, density, and Shore D hardness. The findings show that an enlarged teak wood composition can result in greater water absorption and increased swelling thickness. However, the incorporation of PC added in the ratio of 7.5–15% of PC can result in better dimensional stability and decreased water absorption. Wood and PC are also added, which enhance the hardness with respect to pure polyethylene. Through Taguchi method analysis indicate that teak wood content is the most contributing factor towards these properties, followed by PC content and particle size, being least. The results also show that the model L7 type can provide the most balanced performance against mechanical and physical properties. It can be observed from the present work that the wood-plastic composites used have good mechanical properties and good moisture resistance, and are highly suitable for sustainable engineering applications.