A new strategy for bamboo ultra-long radial slice preparation and novel composite fabrication

Abstract

Bamboo has high-mechanical-strength fibers arranged longitudinally in its growth direction. However, its hollow structure has nodes and uneven density walls, which complicate bamboo processing and utilization. In this study, a method for preparing bamboo ultra-long radial slices (BURSs) along the bamboo growth direction and using the corollary equipment was proposed. New BURSs with a curling shape were collected regularly and weighed to be approximately the same. Several groups of BURSs with the same quality were regularly arranged and pressed into BURS composites (BURSCs) with density of 0.5, 0.6, 0.7 or 0.8 g/cm3. The BURSs well retained fiber integrity. The BURSC with density of 0.7 g/cm3 showed a higher strength-to-density ratio (S: D) than wooden oriented strand board (OSB). Its modulus of rupture, modulus of elasticity, internal bond strength and thickness swelling were 47.5 MPa, 3723 MPa, 1.03 MPa and 3.61%, respectively. Furthermore, a novel BURS processing mode which was optimized into bamboo medial slices with thin edge and green strips with triangular cross-section was proposed. Drum-shaped cross-section with thinner edge improved flowability of bamboo slices during hot pressing and optimized the structure of the composites. This BURS was a novel high-quality component of bamboo boards with high surface quality, strip strength, efficient producing and easy assembling of bamboo strands. The BURSC was proved to be an upgrade product of bamboo OSB and bamboo plywood with high S: D, excellent surface quality and high utilization rate of bamboo.