Natural Lignocellulosic Fibers as Engineering Materials—An Overview

Abstract

Recent investigations on the tensile properties of natural cellulose-based fibers revealed an increasing potential as engineering materials. This is particularly the case of very thin fibers of some species such as sisal, ramie, and curaua. However, several other commonly used fibers such as flax, jute, hemp, coir, cotton, and bamboo as well as less known bagasse, piassava, sponge gourde, and buriti display tensile properties that could qualify them as engineering materials. An overview of the strength limits attained by these fibers is presented. Based on a tensile strength vs density chart, it is shown that natural fibers stand out as a relevant class of engineering materials.

Fique Fiber Tensile Elastic Modulus Dependence with Diameter Using the Weibull Statistical Analysis

“…From 100 fibers randomly selected from the bundle, each corresponding equivalent diameter was directly measured in a model 6C Nikon profile projector. The equivalent diameter was obtained, following procedures indicated in several works 1,[24][25][26][27][28] , as an average between the larger and smaller (90° rotation) cross section dimensions at five locations along the fiber's length. By considering the fiber with irregular cross-section (distinct dimensions in 90° rotation), the average measurements were associated with the fiber equivalent diameter.…”

“…In less than 20 years, more than one thousand scientific papers have been published on the characteristics and properties of hundreds of different fibers and distinct sub-species. These figures are certainly increasing owing not only to the potential of plants with promising fibers but also to the possibility of replacing synthetic fibers in terms of environmental, economical, societal and technical advantages 1 . One should not be surprised by this remarkable potential if it is accepted that only wood encompasses around 10,000 distinct species.…”

“…One should not be surprised by this remarkable potential if it is accepted that only wood encompasses around 10,000 distinct species. In principle, for each lignocellulosic species of plant, fibers with distinct properties from different parts, such as leaves, stem, fruits, and even roots could be extracted for engineering purposes 1 . Today, one of the motivations for investigating lignocellulosic fibers is the possible substitution for synthetic fiber in polymer composites.…”

Ballistic Efficiency of an Individual Epoxy Composite Reinforced with Sisal Fibers in Multilayered Armor

“…Moreover, these composites were applied in several engineering sectors, particularly, the automotive industry [24][25][26] . In particular, the sisal fiber extracted from the leaves of the Agave sisalana plant, native of the Amazon region, was reported to have a density of 1.26-1.50 g/cm 3 , tensile strength of 287 -913 MPa and Young's modulus of 9 -28 GPa [19] . Epoxy composites reinforced with 30% sisal fibers reached Charpy impact energy over 330 J/m [27] .…”

“…Figure 6 presents the fracture region of a sisal composite after penetration by fragments (projectile/ceramic) resulting from the initial impact suffered by the front Al 2 O 3 ceramic tile. In this figure, the main feature is the separation of sisal fibers in thinner fibrils, which is a characteristic of its mechanical rupture 19 . This contributes significantly to absorb the impact energy.…”