Why natural fibres?
A sustainable choice
Renewable and carbon neutral, natural fibres leave residues that can be used to generate electricity. And they are 100% biodegradable
Natural fibres will play a key role in the emerging “green” economy based on energy efficiency, the use of renewable feed stocks in polymer products, industrial processes that reduce carbon emissions and recyclable materials that minimize waste.
Natural fibres are a renewable resource, par excellence – they have been renewed by nature and human ingenuity for millennia. They are also carbon neutral: they absorb the same amount of carbon dioxide they produce. During processing, they generate mainly organic wastes and leave residues that can be used to generate electricity or make ecological housing material. And, at the end of their life cycle, they are 100% biodegradable.
An FAO study estimated that production of one tonne of jute fibre requires 10% of the energy used for the production of one tonne of synthetic fibres (since jute is cultivated mainly by small-scale farmers in traditional farming systems, the main energy input is human labour, not fossil fuels). Processing of some natural fibres can lead to high levels of water pollutants, but they consist mostly of biodegradable compounds, in contrast to the persistent chemicals, including heavy metals, released in the effluent from synthetic fibre processing.
More recent studies have shown that producing one tonne of polypropylene – widely used in packaging, containers and cordage – emits into the atmosphere more than 3 tonnes of carbon dioxide, the main greenhouse gas responsible for global warming. In contrast, jute absorbs as much as 2.4 tonnes of carbon per tonne of dry fibre.
The environmental benefits of natural fibre products accrue well beyond the production phase. For example, fibres such as hemp, flax and sisal are being used increasingly as reinforcing in place of glass fibres in thermoplastic panels in automobiles (at right). Since the fibres are lighter in weight, they reduce fuel consumption and with it carbon dioxide emissions and air pollution.
But where natural fibres really excel is in the disposal stage of their life cycle. Since they absorb water, natural fibres decay through the action of fungi and bacteria. Natural fibre products can be composted to improve soil structure, or incinerated with no emission of pollutants and release of no more carbon than the fibres absorbed during their lifetimes.
Synthetics present society with a range of disposal problems. In land fills they release heavy metals and other additives into soil and groundwater. Recycling requires costly separation, while incineration produces pollutants and, in the case of high-density polyethylene, 3 tonnes of carbon dioxide emissions for every tonne of material burnt. Left in the environment, synthetic fibres contribute, for example, to the estimated 640 000 tonnes of abandoned fishing nets and gear in the world’s oceans.