Pulp fibre foams: Morphology and mechanical performance

Cellulose (pulp) fibre foams serve as bio-based alternative to fossil-based cellular lightweight materials. The mechanical properties of cellulose fibre foams are inferior compared with traditional polymer foams and available information is often limited to compression properties. We present a comprehensive analysis of cellulose fibre foams with densities ranging from 60 to 130 kg/m³, examining their compression, tensile, flexural, and shear properties. Key findings include a high mean zenithal fibre angle which decreases with increasing density, as well as a high strain rate amplification (SRA) in compressive strength, which also decreases with increasing density. With respect to formulation, the addition of carboxymethyl cellulose (CMC) enhanced fibre dispersion, bubble homogeneity of the wet foam, and dimensional stability of the end-product. These results provide a foundation for numerical models and advance the understanding of cellulose pulp fibre foams, highlighting their potential for certain applications.