Above food, below insulation
Straw is available as a by-product in the agricultural industry in abundance. Since only about 1/3 are needed to produce humus, we make the best out of it: The most sustainable insulation in the world!
In some countries like Italy or India, the straw is being burned on the field, which often leads to smog during the harvest time. In the past, straw was still used as litter, but it´s use decreases every year due to split flooring. Other uses of straw are therefore good for the environment, and help farmers to find new sources of income.
The structure of a straw
1. Epidermis with stomas: The epidermis makes up the upper layer in higher plants like wheat. It is protected by cutin, a natural polyester, in combination with cellulose, pectin and wax in order to protect it from mould and parasites. Pectin strongly delays the water absorption and protects the insulation from mould.
2. Outer parenchyma During growth, it´s the parenchyma layer in which water and nutrients are stored. In its dried state, this layer adds to the water absorbance of the straw and thus the proper amount of moisture inside of a building.
3. Sclerenchyma ring and strips: The Sclerenchyma forms the wooden part of the straw. Simply said, a straw is essentially just the same as a tiny tree trunk, just with a significant amount of silica; Natural minerals that decrease it´s ability to burn.
4. Inner parenchyma tissue: see outer parenchyma tissue.
5. Vascular bundles: Through the vascular bundles, the plant receives it´s nutrients and water. During the harvest, those bundles already have no more water, which is why straw doesn´t require additional technological drying processes.
6. Lumen: The lumen of a straw is protected with an almost waterproof layer of cutin. This is what enables us to drink a drink through a straw as well. In ISO-straw, this layer leads to a very slow water absorption by the fibres.