The Core Ingredients
EXO achieves high polymer replacement levels in plastics by harnessing the power of the polysaccharides naturally found in powdered Oyster shell. The EXO formulation includes a few secret ingredients but they are naturally occuring and bio-renewable. The core ingredients are:
Calcium Carbonate is a chemical compound with the formula CaCo3. Calcite is a naturally occuring polymorph of CaCo3 and it is the primary mineral found in limestone and marble. Powdered Calcite is widely used as a filler in the production of plastics but it comes from mining and quarrying. The Oyster shell used to make EXO also contains Calcite but it is organic and renewable.
Aragonite is the crystalline form of calcium carbonate. Like Calcite, an organic version is found in Oyster shell. Aragonite has an orthorhombic crystal structure which helps it to integrate well with polymers. This helps blends of plastic + EXO establish a stable material structure compared to using conventional fillers. Organic Aragonite is also a bio-renewable material.
In the nacreous layer of Oyster shells, the bio-polymer Chitin serves as the major component of the organic framework. Bio-polymers work much like synthetic polymers and it is this ingredient that helps plastics made with EXO retain their strength. Chitin can also accelerate the process of polymer biodegradation given suitable conditions and research is underway regarding this feature.
The EXO Masterbatch
EXO is supplied in pellet form so that it can be mixed with pellets of conventional plastic resin prior to manufacturing. We use a small amount of HDPE plastic to keep the pellet together, but this is less than 10% of the overall pellet mass.
The EXO-Bio Masterbatch (Coming soon)
We are currently conducting research with the assistance of Lancaster University and bio plastic company Novamont to determine if EXO can be used in the manufacture of compostable plastic films. In this case the ingredients will be formed into a pellet using a compostable bio plastic like PBAT. You can read more about this project here.
EXO is made using seashell waste generated by the mariculture industry which is widely considered to be sustainable. Oyster shells actually present a major disposal problem in many coastal regions so the waste stream is being diverted to good effect. There are no GMO issues with EXO and it does not contain a food stock.