Protein: Turning milk into bioplastic
Skimmed milk is routinely wasted in large quantities at raw dairy farms in the UK due to the separation process required to make butter and cream. For her project Protein, designer Tessa Silva decided to save this material from being poured down the drain by turning the milk protein into bioplastic.
The project explores methods of processing the protein that can be extracted from milk, called casein, as a natural alternative to oil-based polymers. Casein can be turned into a bioplastic, though this process as such is not new. During the early 1900s, casein plastics were produced commercially as an alternative to materials such as tortoise shell and ivory. It was made with powdered cow milk, as this contains high levels of protein. However, it faded from use when polymers derived from oil came on the market in the mid 1900s.
Silva adapted and re-envisioned various processes that were originally employed by casein manufacturers to cater the use of fresh milk, sourced straight from dairy farms that otherwise would have gone to waste because of the low milk prices in the UK. The fundaments of the plastic production from liquid milk involve the separation of milk curds from whey by the addition of an enzyme, similar to cheese-making processes.
The casein material is quite unique in both its properties and the production processes that can be applied to it. Although referred to as a plastic, it also possesses qualities comparable to other natural materials such as horn and clay, and can be machined similarly to wood. Therefore, it allows for a lot of creative freedom when it comes to designing the various processes to apply to this material. Silva used it to make tabletops, tableware and vases.
Not only can it be treated as a commercial thermoplastic allowing for compression moulding, injection moulding, et cetera, it can also be hand sculpted for a more crafted and organic result than other plastics.
With the use of casein plastics, Silva seeks to promote the consumption of sustainable products and supporting a local economy.
Photos: Tessa Silva