Corn husk, corn cob

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Corn husk, corn cob

From Chiang Mai

Generally, corn fields in Chiang Mai province are in the uplands where the corn is planted once a year at the beginning of the rainy season (around May or June) and harvested three months later. Only corn kernels are used for animal feed, leaving corn husks and cobs as agricultural waste. Since the region is isolated, it is difficult and expensive for farmers to bring in heavy machinery to clear their land of this waste. As a result, mountains of dumped corn waste form. These attract vermin and other pests and increase the risk of wildfires. These mountains are burnt in advance of the next planting season resulting in an atmospheric haze effect between February and April every year. This significant level of environmental pollution in the region has a negative effect on socioeconomic development, tourism, public health, and global efforts to moderate climate change.

This project aims to reduce or eliminate the problem by developing economically attractive uses for corn waste with an emphasis on environmentally sustainable practices. The design proposal is the use of corn-husk fibres to manufacture panels that can be used in local construction for sound and thermal insulation. Charcoal from corn cobs can be added to give smell and moisture absorption qualities.

The manufacturing process uses local craft skills and some tools from the existing local paper-making trade so it should be easy for the community to learn and integrate into their lives. Starting from extracting fibre from corn husks by boiling corn husks with ash from household waste and making biochar or charcoal from corn cobs. Then, mash together corn husk fibre and corn cob charcoal by using a mortar and pestle which is a standard cooking implement in the area, and add cassava starch, which is readily available and used by locals for cooking food. The final step is to form panels by pouring the final mixture into flat rectangular moulds and allowing it to dry for a few days.

The panels can be used for intra-wall, floor and roof insulation and in interior design for flooring, partitions, furniture, ceiling, and sun shading. It is proposed to initially manufacture to a size of 600 x 1200 mm (a quarter of the standard construction panel size). The size of the panel is therefore designed to allow transport to local markets or users in the large baskets which are traditionally used by local farmers for transporting produce and materials locally by foot.

Fundamentally, it is hoped to achieve a new reality and a new mindset whereby corn waste is no longer seen as waste but as material that has the potential to improve human well-being and the ecosystem. It is hoped therefore not just to increase the value of corn waste in a purely financial sense but also in a more emotional sense whereby local communities perceive the waste as something inherently useful that “adds value” to their life and surroundings. Indeed that it is no longer viewed as waste but as a valuable resource.

Text submitted by the maker

Ingredient list

Corn husks, corn cobs, cassava starch

Photo credits

Tom Mannion