Wood, a renewable and versatile resource, plays a key role in the construction and furniture industries due to its high strength, durability, and sustainability. However, nearly half of the lumber becomes waste during processing. Conventional methods convert these by-products into boards using synthetic adhesives linked to toxic emissions. To address this, recent studies have focused on producing sustainable biocomposites by utilizing wood residues rich in lignocellulosic components without synthetic adhesives. In this study, kraft, and holocellulose fibers obtained from spruce woodchips were combined with lignin as a natural binder under hot compression molding to develop eco-friendly biocomposites. Kraft fibers were obtained via kraft pulping, while holocellulose fibers were prepared using the peracetic acid treatment. The fibers were swelled in 4 wt% NaOH, washed with 50% ethanol-water solution, and impregnated with lignin supernatant overnight. Biocomposites were hot-pressed at 160°C and 190°C under pressures of 15, 30, and 45 MPa to evaluate the impact of processing parameters on bending strength.The results revealed that bending strength decreased with lower applied pressure, emphasizing the synergistic effect of temperature and pressure. High temperatures facilitated lignin melting, allowing it to act as an effective binder, while high pressure ensured fiber-lignin contact for enhanced mechanical properties. Biocomposites made from holocellulose fibers exhibited higher bending strength, surpassing 100 MPa, compared to kraft fiber composites. This improvement is attributed to the more preserved structure of holocellulose, which retains hemicellulose that can break down into adhesive-like compounds such as HMF and furfural during hot pressing. The findings highlight the potential of lignin-bound biocomposites as a sustainable alternative to conventional wood-based materials, offering enhanced mechanical properties, reduced reliance on synthetic adhesives, and better utilization of wood-processing by-products, contributing to circular economy goals in the wood-based industry.