Do you know how much stress we’re under? Life as a lightweight cap

Technological advances means there is still room for the next generation of lightweight caps and closures to offer further savings on cost, according to plastic manufacturer Borealis.   

Borealis, in conjunction with Borouge, is expanding its BorPure MB5568 high density polyethylene (HDPE) into Asia this month, in response to the global beverage industry’s trend for lightweighting. 

Lightweight packaging uses less material, weigh less, and boosts a company’s environmental credentials.

'A wonder of engineering'

But Russell Tew, marketing manager advanced packaging and fibre, Borealis, told BeverageDaily.com the plastic for caps and closures still need to be able to take the same stresses and strains.

Lightweight caps are a wonder of engineering,” he said. “When you look at how much goes into the polymer design and cap design – people don’t realize the stresses on those caps and bottles. 

In the past, you might have seen a cap height of around 12mm or 10mm. If it’s getting towards 7mm or 6mm, it’s still very easy on still water, but not easy on carbonated drinks.

You can imagine a shop window in the summer, with the sun coming into this bottle of fizzy water, you get significant pressure. It’s about how to accommodate that pressure, and open bottles in a safe way. And then at the same time, to make it lightweight.”

The MB5568 has a 50% improvement on the ESCR (Environmental Stress Crack Resistance) on its predecessor (MB6561), meaning it can take more strain without cracking, the company claims.

It can be used for caps on carbonated soft drinks, juices, teas and bottled water.

Improve on sustainability and cost

All the major brands are looking for the same thing,” Tew said. “They’re looking to improve on sustainability and cost. We’re aiming BorPure at a global market and we’ve already received a lot of interest from the great global players.

BorPure MB5568 has been developed to reduce the amount of plastic used, which in turn reduces the weight for transportation and carbon footprint. It does not influence taste or odour of the drink, Tew claims.

But with the need to retain strength and safety in plastic and closures, how much further can lightweighting go?

If you’d asked that question 20 years ago we’d have said we were close to the limit,” Tew said. “But technology has advanced and we’ve reached where we are.

With our Borstar technology we still have room to go with the next generation. How much this is, it’s too early to say. But there is room for development.

The BorPure MB5568 made its debut in Europe earlier this year. It will be launched in Asia at Chinaplas 2014 in Shanghai from April 23 – 26.