Natural fibres in composites will provide benefits for industries in South Africa

published: June 4th, 2010
author: Dimakatso Motau
website: http://www.engineeringnews.co.za

The composite materials industry has the potential to contribute to the growth of the local economy, says the Council for Scientific and Industrial Research (CSIR) chief researcher and research group leader for composite materials Dr Rajesh Anandjiwala.

This view is also supported by the Department of Science and Technology (DST) and the Department of Trade and Industry, which have identified the growth of natural fibre-based industries as a significant agro economic tool.

Anandjiwala says that South Africa has the potential to become a tier-two supplier of composite products in future. However, he adds that the country must aim to become a tier-one supplier for higher benefits and job retentions.

However, to achieve this, the country must overcome certain challenges in the composites industry. Anandjiwala points to a lack of raw materials being manufactured locally, which results in the import of certain raw materials, such as natural fibres, some speciality chemicals and resins. He says the development of the industry is also hindered by the lack of a skilled workforce.

He adds that natural fibres in composites will also provide other benefits for industries in South Africa. The advantages of using natural fibres in composites include its light weight, which results in weight saving, a cheaper raw material price from the natural source, thermal recycling and the ecological advantages of using renewable resources, he explains.

Further, natural fibres provide safer handling and working conditions com- pared with synthetic reinforcements. These products are nonabrasive to mixing and moulding equipment, which can contribute to significant cost reductions.

There is also a substantial composite materials demand for partition boards, small aircraft structures, automotive com- ponents, components for household appliances and marine and recreation vehicles.

Anandjiwala says that, currently, there is a demand for natural fibre composites in the automotive and aerospace industries.

“The common natural fibres used in composite materials are flax, hemp, jute, kenaf and sisal, owing to their properties, easy availability and good performance-to-price ratio. Most nonstructural components, such as head/trunk liners, parcel trays, side liners for the automotive industry and other sectors, are now made from natural fibre composite materials,” he adds.

Current Developments

In the field of natural fibre composites, developments include imparting fire resist- ance to natural fibres and the processing of composites by a vacuum-assisted resin infusion.

Other developments include, the designing of natural fibre composites by sheet moulding techniques for the construction sector. This technique is cost effective and can result in complex shaped products with a high- volume of production, says Anandjiwala.

He explains that these projects focus on natural fibre reinforced polymer com- posites for various industrial applications, such as the automotive and aeronautical sectors. These include the development of natural fibre thermoset composites, for use as secondary structures in aircrafts.

The latest development in the transport industry is to fully obtain the performance benefits of composite materials, while lowering production and operating costs and reducing its environmental footprint. This has been a challenge so far, Anandjiwala explains

Another development includes the use of natural biopolymers, such as soy protein isolate, polylactic acid and polyfurfuryl alcohol as the matrices, and the use of woven and nonwoven natural fibres as reinforcement agents for various applications, he says.

Further, the development of biodegrad- able packaging for the South African fruit industry includes the use of bioplastic and biopolymers from renewable resources, which allows for the development of compostable packaging for fresh produce, besides affording improved functionalities.

This project has identified several products, ranging from disposable and return- able crates to multifunctional flexible pack- aging and the development of cellulose- and chitin-based bionanocomposite fibres for textile and biomedical applications, he concludes.