The CSIR’s Dr Rajesh Anandjiwala, under whose leadership the prototype natural fibre based insulated sandwiched panel has been developed. Here he holds a small sample of the prototype. |
One of the projects that form part of the new strategic investment areas within the CSIR deals with the use of natural fibres in construction products. This initiative seeks to make a meaningful contribution to the concept of bio-based housing. As part of this project, a prototype natural fibre-based insulated sandwiched panel has been recently developed at the CSIR under the leadership of Dr Rajesh Anandjiwala. The project has a strong focus on both materials and application-oriented product development.
The prototype product
The insulated or roof panel in question is nothing more than a sandwich type of structure. The sandwich structure consists of an expanded polystyrene centre and outer layers consisting of a natural fibre polymer composite.
Polystyrene is well-known by both experts and consumers as an effective insulator. A polymer is commonly referred to as a plastic. A composite is the combination of at least two materials, natural fibre (flax) and polymer in this instance, which remain distinguishable after they have been combined. This is done to make stronger, better materials that can be used in all kinds of applications.
Some benefits of the newly-developed roof panel include lower weight, lower cost and inherent insulation compared to traditional roofing products. It is also environmentally friendly due to use of naturally renewable flax fibres.
An environmentally-aware world
“The construction sector is under considerable pressure from government and clients to improve the quality of its products, reduce its economical, social and environmental impacts, and increase the rate of delivery.” |
As the world becomes more environmentally aware, the drive towards eco-friendly materials and products has gained momentum. We thus have to rethink the materials we use on a daily basis for packaging, building and manufacturing, so that when these materials reach the end of their life cycle, they would simply be absorbed back into the earth in a way that would not harm the environment.
In recent years, there has been a growing interest in the use of natural fibres in composite applications, especially in the aerospace and automotive industries. These types of composites present many advantages compared to synthetic fibre reinforced plastics such as low tool wear, low density, low cost, availability and biodegradability. In addition, the construction sector is under considerable pressure from government and clients to improve the quality of its products, reduce its economical, social and environmental impacts, and increase the rate of delivery to meet the growing demand of its domestic markets, especially for affordable housing.
The development of construction products that utilise renewable resources in an environmentally-sustainable manner will therefore greatly assist the industry in meeting these emerging expectations. Furthermore, developing countries like South Africa suffer a serious backlog of low-income or affordable housing with the figure being put at up to 3 million for South Africa alone. Technologies that can offer a quick, low-cost delivery of such houses would be most welcome for the middle and low-income sectors of the community.
The current project is well-suited to address, along with other initiatives within the CSIR and nationally, the abovementioned needs.
The challenge: finding a biodegradable polymer composite
Unfortunately, most polymer composites are not biodegradable and therefore environmentally unfriendly. This is especially the case with glass fibre composites, one of the strongest composite materials around.
Who is involved?
Dr Rajesh Anandjiwala headed up the project. Other researchers involved include: Drs Babu Guduri, Rakesh Kumar, Maya John and Andrew de Vries.
The built environment expertise and guidance of Llewellyn van Wyk and Dr Joe Mapiravana is an essential part in the product development and design aspects of the project.
International involvement by Professor Richard Wool from the University of Delaware (USA) is of further value to the success of this project.
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In our case, the natural fibre polymer composite can be considered as a semi-environmentally friendly composite. The polymer (resin) that is currently used for the composite part of the sandwich panel is not derived from renewable resources, but is from petroleum products. Therefore, future research will focus on the development of fully bio-based composites.
A bio-based (natural and biodegradable) matrix reinforced by natural fibres also provides an important additional advantage, as renewable resources are used instead of petroleum-based materials. Already existing capabilities in the area of renewable matrices in the CSIR will see the advancement of fully bio-based composites.
Furthermore, the current polystyrene core used in the manufactured roof panel presents further environmental challenges. The challenges are three-fold: developing an alternative to polystyrene that is eco-friendly, low-cost, and with good insulation properties.
Ongoing research at the CSIR on bio-cores proposes to address these in a phased development.
Revolutionising the South African construction industry in the long run
The generation and exploitation of new knowledge, and thus innovation, is at the heart of the National System of Innovation and the Department of Science and Technology’s Ten-year Innovation Plan. The transferring of technologies and skilled human resources is another major aim of these programmes.
With this in mind, it is foreseen that this project will contribute to these aims. It is also optimistically predicted that projects of this nature will be a factor in revolutionising the South African construction industry in the long run. A major challenge in this regard is to locally produce the product and generating the uptake by the construction industry.
Enquiries:
Dr Rajesh Anandjiwala
ranandi@csir.co.za
Enquiries:
Dr Andew de Vries
AdeVries@csir.co.za
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