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Feature: The story behind Yowk

08 March 2016

Brian Lodge of RPC Design explains the packaging challenges behind creating the perfect boiled egg

Google the question ‘how to boil an egg’ and you will find plenty of conflicting advice, particularly regarding the number of minutes you should allow for the ‘perfect’ egg with a firm white and runny yoke.

Now The New Egg Company has come up with an innovative solution that allows consumers to achieve a perfectly boiled egg every time. Yowk is a pre-boiled egg to which hot water simply needs to be added for five minutes.  And as well as taking the guesswork out of egg preparation, this solution also provides consumers with a healthy ‘on the go’ snack that can be enjoyed whenever and wherever required – as well as having the potential to be offered in cafés and coffee shops.

Food science has ensured the perfect boiled egg – packaging science was needed to create the perfect pack for this new concept, one that would not only retail the egg but be used to heat it and eat from.

There were a number of critical issues to address in developing the pack.  Most important of all was to ensure that it would take the exact volume of water to re-heat the egg.  Too little would not heat the egg enough while too much would carry on the process and solidify the yolk.  At the same time, the distribution of the water was crucial to make sure the egg was heated throughout.

Plastic gets softer when it is heated; the design had to take this into account so that the pack would not distort when filled with water and be easily handled without spilling the contents.

Eggs may have a familiar shape but they are certainly not of uniform dimensions. And as Humpty Dumpty will attest, their fragility is legendary!  The pack therefore needed to hold and protect the egg during transit, as well as providing a means of eating it.  And as no boiled egg can be properly enjoyed without the traditional accompaniments, the pack also had to contain bread sticks and seasoning as well as a spoon.

The first step in creating the pack was to identify the best plastic processing technology to produce it – thermoforming was selected as being able to meet both the technical requirements and the right price point.

The design process began with a series of experiments using mock-ups created from current packs that we manufacture.  This enabled us to determine the size and volumes required as well as assessing and agreeing some of the mechanical properties.

The next stage involved the use of 3D printed models.  With these more accurate concepts, we were able to ensure that all the requirements of the initial design brief were being met and check that the overall functionality of the pack was in line with what we had planned.

One of the most difficult areas to resolve was the issue of the pack distorting when it was filled with boiling water.  This is where being an in-house design facility and able to consult directly with the people who are going to manufacture the pack is a huge advantage.

The thermoforming process creates a thin wall section, so we needed to combine our design experience with the knowledge of the technical manager to come up with a solution that would prevent any distortion.  This focused on devising a complex series of features in the base that gave the overall pack the strength to withstand the heat.  Importantly, this was achieved without the need for any extra amount of polymer.  The pack is manufactured on our existing in-line thermoforming machines.

For any retail pack, aesthetics are important; for a convenience product, functionality is critical.  The pack has a colourful cardboard sleeve while the natural polypropylene allows the egg to be visible.  As well as delivering the necessary overall strength, the base of the pack provides a hollowed out section for the egg to sit in.  So that the egg can be enjoyed straight from the pack, the snap-on lid doubles as an egg cup and, when the pack is closed, the hollow part of the cup fits over the egg.  Together these two features ensure the egg remains stable during transit.

The dimensions of the pot are exactly right for the amount of water required and they also provide the space for the bread sticks, seasoning and spoon.

A perfect egg takes five minutes – the perfect pack can take a little longer to create!

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