1 - Natural fibres: types and properties

Abstract

Publisher Summary Natural fibre is defined as fibrous plant material produced as a result of photosynthesis. These fibres are sometimes referred to as vegetable, biomass, photomass, phytomass, agromass, solarmass or photosynthetic fibres. In terms of utilization, there are two general classifications of plants producing natural fibres: primary and secondary. Primary plants are those grown for their fibre content while secondary plants are those where the fibres come as a by-product from some other primary utilization. Jute, hemp, kenaf, sisal and cotton are examples of primary plants while pineapple, cereal stalks, agave, oil palm and coir are examples of secondary plants. The most common classification for natural fibres is by botanical type. Using this system, there are six basic types of natural fibres: bast fibres; leaf fibres; seed fibres; core fibres; grass and reed; and all other types such as wood and roots. There are many reports in the scientific literature on the mechanical properties of natural fibres. Many factors influence mechanical properties of natural fibres. The density data represents the apparent density, which is the density of the whole fibre, not the fibre cell wall. All of the natural fibres have a cell wall density of approximately 1.5 g/m3. There is a very wide range of physical properties depending on the fibre type. In general, bast fibres are the strongest.