Article updated on 17 August 2021.
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Researchers at the Forest Products Research and Development Institute of the Department of Science and Technology (DOST-FPRDI) in the Philippines have developed a method of bamboo preservation that utilizes a hot oil treatment. The technology, inspired by Europe’s thermal modification (TM) process, is a more environmentally friendly way of preserving the material and protecting it from pests and fungi. As bamboo is an important building material in the Philippines that is considered sustainable, this technology will likely positively impact the building industry and the country’s environmental impact.
Bamboo as a Sustainable Building Material
Since ancient times, bamboo has been used as a natural construction material, particularly in areas where the plant grows in tropical and mild temperate climates. Its properties, such as its flexibility and strength, have helped cement the material as a go-to building material in many global regions. However, in the 1980s during the global shortage of housing materials, the material saw a resurgence in popularity as it was selected for its low cost and durability. Since then, bamboo has been developed into other materials more suited to the needs of modern construction projects.
A high level of interest in bamboo, not only as a construction material but as an alternative material for various uses, partly due to its environmental benefits and position as a green material. Unlike other natural building materials, such as wood, bamboo benefits from its very fast growth rate, making it more suitable for afforestation. The harvesting of bamboo in a sustainable manner has less of a negative impact on the environment than other building materials. Scientists suggest that sustainable harvesting of bamboo can be achieved by cutting 20% off the top of mature stems, allowing their height to be replaced annually, maintaining the abundance of the plant. However, bamboo harvesting is not without its drawbacks and environmental impact, as there is some evidence to suggest that it may impact species variety.
Overall, bamboo is a valuable and affordable building material considered more sustainable than its counterparts. For this reason, techniques to preserve the material are essential for ensuring the longevity of the buildings it is used to construct. Here, we discuss a new process developed by DOST-FPRDI in the Philippines that will support bamboo in the future.
Developing a New Technique of Bamboo Preservation
The new “hot oil bath” technology developed to preserve bamboo was carried out by DOST-FPRDI and funded by DOST-Philippine Council for Agriculture, Aquatic and Natural Resources (PCAARRD). The project successfully created a method of preserved bamboo by reusing spent cooking oil. As a result, the technology benefits the industry as it utilizes a waste product and maintains a sustainable building material.
The new method uses spent cooking oil in place of fresh vegetable oils to lower the cost of heating the medium. The equipment manufacture is significantly cheaper than similar technologies imported into the country, making it more affordable to buy and run for businesses in the Philippines.
The technology works on the principle that heating wood or bamboo with extremely high temperatures (160 °C to 240 °C) destroys the nutrients in the material that attract insects and, at the same time, kills any fungi that the plants may harbor.
So far, the equipment has been tested on 8 ft-long bamboo poles. The resultant treated poles were said to be characterized in terms of “machinability, gluability and finish ability,” according to the DOST chief. Such characteristics enhance bamboo’s properties as a construction material. It was also noted that bamboo pole tests helped establish optimal oil heat treatment conditions.
A Safer Method of Protecting Bamboo Growing in Popularity
The new technology provides a method of treating bamboo that does not require toxic chemical preservatives conventionally used to protect the material from insect and fungi infestations.
The technology, which originated and initially gained popularity in Europe, looks poised to impact Southeast Asian countries, including the Philippines, significantly. In addition to protecting the material and reducing the environmental impact of preservative processes, the new hot oil treatment also improves the bamboo’s dimensional stability and color.
Establishing Bamboo as a Sustainable Alternative Material
Bamboo has already enjoyed a resurgence in popularity due to its strength, flexibility, and low cost, making it an accessible building material. In recent years, there has been a focus on its sustainability. While the material is not 100% sustainable, particular harvesting practices must be observed to minimize its environmental impact as much as possible. In general, it is considered more sustainable than alternative materials such as wood.
The new oil heat treatment technology to preserve bamboo will likely help further bamboo’s popularity as a building material, helping to reduce the environmental impact of the construction industry.
References and Further Reading
'Hot oil bath’: PH develops alternative method of preserving bamboo using oil heat treatment. Charissa Luci-Atienza. Manila Bulletin. Available at: https://mb.com.ph/2021/05/09/hot-oil-bath-ph-develops-alternative-method-of-preserving-bamboo-using-oil-heat-treatment/
Manandhar, R., Kim, J. and Kim, J., 2019. Environmental, social and economic sustainability of bamboo and bamboo-based construction materials in buildings. Journal of Asian Architecture and Building Engineering, 18(2), pp.49-59. https://www.tandfonline.com/doi/full/10.1080/13467581.2019.1595629
Salzer, C., Wallbaum, H., Lopez, L. and Kouyoumji, J., 2016. Sustainability of Social Housing in Asia: A Holistic Multi-Perspective Development Process for Bamboo-Based Construction in the Philippines. Sustainability, 8(2), p.151. https://www.mdpi.com/2071-1050/8/2/151