Densification of Bamboo: State of the Art

Author(s)

Kadivar, Marzieh ^[1] ; Gauss, Christian ^{[1, 2]} ; Ghavami, Khosrow ^[3] ; Savastano, Holmer ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Biosyst Engn, Res Nucleus Mat Biosyst NAP BioSMat, BR-13635900 Pirassununga, Sao Paolo - Brazil

^[2] Univ Waikato, Sch Engn, Hamilton 3216 - New Zealand

^[3] Pontificia Univ Catolica Rio de Janeiro, Dept Civil Engn, BR-22453900 Rio de Janeiro - Brazil

• Document type: Review article
• Source: MATERIALS; v. 13, n. 19 OCT 2020.
• Web of Science Citations: 1

Abstract

Densification processes are used to improve the mechanical and physical properties of lignocellulose materials by either collapsing the cell cavities or by filling up the pores, consequently reducing the void volume fraction. This paper focuses on an extensive review of bamboo densification process, which is achieved by compressing the material in the direction perpendicular to the fibers using mainly two different techniques: an open system, thermo-mechanical (TM), or a closed system, viscoelastic-thermal-compression (VTC). The main aim of bamboo densification is to decrease its heterogeneity, as well as to improve its mechanical and physical performance. In addition, densification may occur during the manufacturing of bamboo products in which hot-pressing processes are used to mold bamboo panels. There are over 1600 publications about bamboo, concentrated in the recent decade, mainly about engineered materials. Although several papers regarding bamboo and wood densification are available, very few studies have comprehensively investigated the densification process solely through compression of natural bamboo culms. According to the literature, applying a combination of compression of 6-12 MPa at temperatures between 120-170 degrees C for 8-20 min can produce materials with higher strength in comparison to the mechanical properties of natural bamboo. The majority of research on bamboo densification indicates that the modified material results in improved properties in terms of density, hardness, bending strength, stiffness, and durability. This paper provides a review that consolidates knowledge on the concept of bamboo culm densification, discusses the roles of parameters that control the process, ascertains the best practice, and finally determines gaps in this field of knowledge. (AU)

• FAPESP's process: 19/24253-1 - Development of high-performance materials based on bamboo through densification process
• Grantee: Marzieh Kadivar
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/26022-9 - Preservative treatment and chemical modification of bamboo for structural purposes
• Grantee: Christian Gauss
• Support Opportunities: Scholarships in Brazil - Doctorate