The weekly Verdigris blog by Laurel Brunner
When we think of the circular economy, hard boiled eggs aren’t necessarily what comes to mind. But they can make an important contribution, particularly when it comes to packaging. Eggs are one of nature’s best examples of effective packaging. Manufactured packaging, mostly using paper and plastics, shares the same goals of product protection, containment and presentation.
Nature’s packaging can contribute to new packaging products. Waste materials are increasingly reused as raw materials for other processes, thereby supporting the circular economy. The production of foodstuffs inevitably produces waste as a byproduct so it makes sense to use it, which is indeed what happens. Waste produced in food processing often gets reprocessed as content in other food products, where the consumer’s expectation is not so demanding. Think sausages, meat pies and chicken nuggets. When it comes to eggs, there are rather more interesting possibilities for packaging supply chains.
Eggs are one of the big inputs for mayonnaise and cooked foodstuffs. They are boiled and cracked on a massive scale to supply the market for mayonnaise, cooked eggs used in sandwiches and such like eggy products. A UK company has come up with a cracking means of processing its wasted eggshells into a new raw material suitable for use in packaging materials. Calcium carbonate, which is what eggshells are made of, has a market value as a mineral filler, so instead of paying for waste disposal, this company is selling on its discarded shells for reuse in another industry.
Just Egg describes itself as “the most modern Boiling Plant in the UK” and the company breaks millions of eggshells every month. Like its cohort in other geographies, Just Egg inevitably produces masses of eggshell waste. This waste has to be removed and buried in landfill, costing money, creating transport emissions and discarding material with potential for another use. This is not in the interests of the circular economy.
According to the Economist newspaper, Just Egg has turned cost into revenue by processing its eggshell waste into mineral filler for use in packaging materials. Used eggshells are minced up at the end of the egg cracking and shell removal lines in the Just Egg factory. Residual proteins are washed away with recyclable water and solvents. The shells, now unadulterated calcium carbonate, are dried and ground up. The degree of strength and flexibility required in the end plastic-based product determines the granularity of the grind.
Calcium carbonate is one of the most popular mineral additives for packaging materials. It provides surface gloss and opacity, improves surface structure and can make plastics more durable. Mineral fillers can also help plastics to biodegrade more effectively when they reach end of life. Calcium carbonate in packaging materials reduces carbon emissions associated with oil based materials and the energy required to produce the package. An eggsellent outcome all round.
– Laurel Brunner
The Verdigris project is an industry initiative intended to raise awareness of print’s positive environmental impact. It provides a weekly commentary to help printing companies keep up to date with environmental standards, and how environmentally friendly business management can help improve their bottom lines. Verdigris is supported by the following companies: Agfa Graphics, Digital Dots, EFI, Fespa, Heidelberg, HP, Kodak, Ricoh, Splash PR, Unity Publishing and Xeikon.
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