Mantou stool is made from 100% biodegradable wheat flour bioplastic. The process of making this stool is inspired by the Chinese mantou, steamed bum, cooking technique. This wheat flour bioplastic is lightweight and strong due to the porous interior structure created from the yeast leavening process. The dehydration process and additional natural additives in the ingredient also make the stool repel pests and resist decaying. Mantou stools can be easily produced at home or in a micro-factory, thanks to the easy and low-cost manufacturing process. The material used in Mantou stool can also be used in many other applications.
Mantou is one of the most important staple foods in the northern part of China. The process of making this stool is inspired by the mantou making technique. Mantou are steamed and have minimal ingredients compared to bread. Water flour and yeast were mixed together for fermentation. During fermentation, yeast consumes the sugar in the dough and produces little air bubbles. When the dough is steamed, those little air bubbles expand and give the mantou porous structure.
In order to create a mantou stool in a single piece, a large steam chamber is needed. I modified a 90-liter metal trash bin by wrapping it with insulation material and connecting it to a steam generator. The Mantou Stool needs to be dehydrated to gain structure strength after being steamed. To speed up the drying process of such big volume. I designed it to have holes that run through the stool to increase airflow and surface area. A mold for the stool is created to fit inside the metal bin. The mold has 24 removable Polypropylene pipes that create the holes that run through the stool.
Each individual pipe was wrapped with a leavened dough sheet and assembled on the mold. During the steaming process, the dough expands in volume and merges with the dough tube next to it, so 24 dough tubes turn into a single piece of volume. After the steaming process, pipes were taken out. The following dehydration process will preserve the stool and give it structural strength for seating.
Bread has a very limited shelf life and grows mold easily. With glycerin, salt, and other natural ingredients added in the mix, the starch in the stool turns into bioplastic and becomes much longer-lasting and resists mold.
Expired flour can be used to create the stool without changing the characteristics of the material. Additive fillers such as sawdust, fiber, and straw can be added in the mix to give the material a different appearance. The mantou stool material is a lightweight strong sustainable material that has many potentials in other design fields including architecture, fashion, and packaging design.
