Valorization of waste pine needle biomass into cushioning material for protective packaging applications: a sustainable alternative to expanded polystyrene

The cushioning material protects fragile goods with high shock absorption properties during storage and transportation. Pine needle pulp-based cushioning material was fabricated with or without guar gum as a binder for rigid  foams and fibrous networks in this work. A relatively simple, low-cost, eco-friendly, and greener approach was applied to develop pine needle-based cushioning material. Processing parameters and internal microstructure are connected to the compressive response. In fibrous networks, the length of the starting fibers and the amount of external fibrillation dictate the possible relative shock absorption capacity. At 0.30, 1.8, and 2.4 m, pine cushioning with guar gum showed superior shock absorption at forces of 1, 2, and 4 kg, while neat pine needle cushioning material exhibited a considerable weight loss at the same height. Pine cushioning capacity decreased significantly (p < 0.05) from 0.051 to 0.025 J, while material with guar gum remained higher; in contrast, neat pine cushioning increased from 0.121 to 0.208 J. The chemical structural analysis of the material showed an integrated reaction with the cellulosic fibers and the guar gum as binding agents to form a stable and rigid foam structure. The morphological view of the pine needle fibrils had an effective arrangement in the foam network with mechanically pressed molds of different shapes. The findings demonstrate the potential of pine needle fiber foam as an inexpensive, lightweight structural component.