 This paper discusses the possibility of obtaining uniaxially rotomolded composite parts from biobased low-density polyethylene, BiOLDPE, filled with black tea waste, by the way. The use of biobased materials is becoming increasingly popular due to their environmental benefits. However, the presence of oxygen in the environment can cause oxidated degradation of these materials, leading to reduced mechanical properties and increased brittleness. This paper investigates the effects of adding by the way to BiOLDPE on its thermal stability and mechanical properties. The results show that adding by the way to BiOLDPE reduces the oxidation levels of the material, as indicated by the decrease in the carbonyl index. Additionally, the addition of by the way does not affect the melting properties of BiOLDPE, while it does reduce the mechanical properties of the composite. This article was authored by Joanna Anisco and Mateusz Barksowski. We are article.tv, links in the description below.