Opportunities and Innovations

the road towards tethered caps

Europe has taken a global leadership role in the fight against pollution and single use plastics. From plastic cutlery to drinking straws or cotton earbuds, the products in your local supermarket are being replaced by more sustainable solutions. This is all thanks to the Single Use Plastics Directive introduced by the European Commission in 2018. It aims to help us transition towards a circular economy, where nothing is wasted, and everything gets a second chance at life.

Tethered Caps

One of the articles in this directive – voted in April 2019 – specifies that all drinks packaging should have tethered caps by 2024. Bottle tops are a major source of pollution, as they are easy to drop and lose once opened.   A tethered cap is connected to the bottle or milk carton by an extra plastic ‘link’. This ensures you don’t accidentally lose the cap, creating litter, and that it is recycled along with the bottle.  A double win for the environment… The solution seems simple, so why not introduce it straight away?

You may not pay much attention to the closure of your drink, but we do.  Years of R&D go into any kind of packaging update, and tethering the cap to your bottle is no different. Even more, this new legislation has the potential to shake up the entire industry.  Because which manufacturer will come up with the winning design?

It’s entirely possible that the best solution at the best price doesn’t come from the number one or two global supplier, but from a smaller player. Especially considering this modification is only required in Europe, and not worldwide. At the start of this year there were some 400 copyright applications for tethered cap designs. That’s four-zero-zero patent applications from all over Europe that need to be studied by the patents office.  And until licenses are awarded, we have to consider multiple options. The differences may seem small but can have a massive impact on the final choice of solution.

User Experience

First off, there is user experience, or consumer comfort. The angle at which the top flips back so you can pour your juice without it spilling everywhere, or drink your water without the cap getting in the way, matters. The top needs to twist open easily, whether you are seven or seventy. Then there is the tensile strength of the link, which is currently being evaluated by the EU Committee of Normalisation.  Beverage companies agree it should be strong enough to provide resistance when a consumer tries to tear it off so they understand it must stay attached.  At the moment, it’s looking like this will be around 25-30 Newton.

Plastic Footprint

Then of course there is the amount of extra plastic needed to create this tether. We’ve been working hard to lightweight our bottles, and we don’t want to lose this advantage. Today our lightest bottle tops are 1,3 grams, while tops for sparkling water are closer to 2 grams.  The CO2 in sparkling water puts pressure on the cap, which means it needs to be stronger and therefore heavier. A tethered cap adds a further 0,2 grams to this plastic weight.  This might not seem like a massive amount, but we use 600 million bottles per year at Spa Monopole alone. And 600 million x 0,2 grams quickly adds up. So we have to consider ways in which we can compensate this extra weight.

Modifications, Moulds and Lines

Finally, these adaptations require changes to the moulds used to create both bottles and caps. This is true both for our suppliers and for our own bottling plants. To save on transport volume, bottles arrive at our sites as pre-forms, which are blown into the final bottle you find in the shop. This high-tech injection moulding technology also means making modifications to our filling lines.  And so the different prototypes are evaluated on a technical level as well as studied for financial and environmental implications.  The main players in the bottling industry are working together to push in the same direction and minimise costs for the moulding industries, filling lines and environment.

With so many players looking to design the best type of tethered cap, competition is high, and the race is firmly on.  These are exciting times in the packaging industry, full of innovation and opportunity. We look forward to keeping you updated.