A sustainable method for preparing lightweight, high-strength, and dimensionally stable superfine bamboo fiber composites

Bamboo fiber composites present an environmentally friendly and sustainable building material. However, traditional methods for preparing bamboo fibers often result in incomplete rolling and uneven fluffing, leading to intact vessels and sieve tubes, as well as an uneven distribution of Phenol-Formaldehyde (PF) resin. These shortcomings cause defects such as cracking and deformation bamboo fiber composites during the application. To address this, a sustainable manufacturing process for superfine bamboo fiber composites was developed. Bamboo strips were pretreated with saturated steam; and then fluffed by the multifunctional fluffer, yielding hair-sized superfine bamboo fibers. Subsequent these fibers were impregnated with Phenol-Formaldehyde (PF) resin, and hot-pressed into lightweight, high-strength, and dimensionally stable superfine bamboo fiber composites (SBFC). Results demonstrate that the average cross-sectional area of bamboo fibers in SBFC measured 0.099 mm², which merely was 10.26 % of common bamboo fiber, demonstrating significant refinement. Compared with conventional bamboo fiber composites (CBFC), SBFC shows 31.6 % higher flexural strength, 25.0 % greater surface hardness, 44.4 % lower surface roughness, 67.1 % reduced water absorption, 59.5 % decreased thickness swelling, and a 38.2 % increase in 30 s surface contact angle. These enhancements reflect substantially improved physical-mechanical properties. These enhancements reflect substantially improved physical-mechanical properties. Furthermore, SBFC also exhibits superior ratio of strength to weight and surface hardness compared with some structural materials with excellent mechanical properties. This work presents high-performance SBFC in a sustainable method, advancing bamboo’s utilization in building engineering applications.