The next time you bake a walnut brownie, think before you throw out the eggshells and nutshells! You could have another creative project on hand- making a waste-based, sustainable biocomposite. These two types of shells- egg and nut- are the key ingredients that product designer Rania Elkalla uses to create her unique material Shell Homage.
This designer’s aim is to create functional and sustainable products made with a beautiful yet fully biodegradable material. In fact, the tiles and products she makes with Shell Homage can be even be composted in the garden. Rania proposes her material innovation as the ultimate solution that will enable consumers to dispose of their “stuff” at the end of use, as opposed to consuming objects and artifacts made from plastics, for example, that last forever in our homes or landfills.
What is Shell Homage?
Shell Homage is a biodegradable composite material made out of nothing but egg and nut shells, there are no other toxic chemicals in the mix. Depending on how it will be applied, the material properties can be controlled and modified. From stiff and hard, to elastic and malleable, it is all possible using the same material. The surfaces can even vary from transparent, to translucent, to opaque, proving how incredibly versatile it can be. Rania also plays with the colour by adding food pigments, that combined with the shell waste, produces surfaces with a look and feel that is similar to marble, natural stone or ceramic, although it is much lighter.
How can Shell Homage be used?
This natural composite material can be pressed, extruded, 3D printed or formed by injection molding, Rania produces each surface by hand, bringing the raw materials together in unique combinations of colors and patterns. Once the pieces are made, they can be drilled, sanded or laser cut. Shell Homage can be used across several industries such as product design, interior design, consumable goods and jewelry design. As a material with endless applications, Rania hopes to establish collaborations with different designers that will embrace the potential Shell Homage offers and transform it into remarkable design pieces.
The Symbiotic relationship between Food and Design
One of the biggest industries in the world is the food industry, responsible for large amounts of waste such as peels and shells. Material makers such as Rania are eager to explore these instead, as valuable raw materials. Egg and nut shells might be easily overlooked but as Rania has discovered, there is more to them than meets the eye.
Let’s dig in a little deeper. Eggshells contain about 95% of calcium carbonate, one of nature’s most absorbent materials, and can capture up to 78% of carbon dioxide in the air. They also contain collagen, a key ingredient, necessary in the development of a biopolymer. There is an average of 1 trillion eggs produced per year worldwide, making it a widely renewable source for shells that can be repurposed into the production of biocomposites for designers and makers worldwide.
On the other hand, Rania claims that around 2.5 million tons of nuts that go to waste every year. Most of the nut weight is contained in its outer shell. For example, walnut shells comprise 67% of the total weight of the fruit. Some of the wonderful properties that are inherent to nut shells are that they are heat, and water resistant as well as very durable and as strong as wood.
During the research and investigation that Rania carried out in the development of Shell Homage, she confirmed that there is no need to throw these nuts and eggshells away, working scientifically to prove that not only are they biodegradable but they also enhance the biopolymer properties.
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