Lightweight PET bottles score very highly, thanks to their minimum use of resources. This pays off well, both for the environment and financially. Photograph: KHS
The lightest bottle in the world
Weighing only five milligrams yet with a capacity of half a litre, the PET bottle from KHS and Husky couldn’t be lighter. Husky, a world market leader, is a Canadian company that makes injection moulding machines. According to KHS’s own figures, the bottle uses about one third less material than the lightest bottle that is currently on the market.
The bottle, which is intended for still mineral water, is called Factor 100 to express the ratio between weight and capacity. But there’s more to this nicely curved bottle than its weight, as it’s also robust to handle and dimensionally stable. Its well-thought-out geometry ensures a particularly high top load, giving the bottle its necessary pressure resistance. Thanks to modern technical solutions in injecting moulding and blow moulding, the PET can be stretched with extreme accuracy across the entire shape of the bottle, achieving optimum efficiency. This also saves on material and improves the CO2 ratio.
There is no contradiction between light and robust – as illustrated by some innovative new bottles, e.g. the Factor 100 bottle from KHS and Husky. Photograph: KHS
Even milk and beer can be packaged lightly. The results obtained by the company’s own Bottles & Shapes Centre show that lightweight PET bottles can maintain a high level of robustness despite a low use of resources. The areas where savings are made are the bottleneck and the thread. For instance, when designing a 0.5-litre beer bottle for a German brewery, KHS reduced the supporting ring and the wall thickness at the bottleneck and thread, yet without affecting the material density or the bottle’s processing qualities on a production line. This enabled them to save 1.6 grams per bottle – well worth it when we consider how many hundreds of millions of litres are bottled each year.
Even beer and milk are increasingly packaged in lightweight PET bottles. Photograph: KHS
If it’s possible for beer and water, then it can also be done for milk. KHS’s ultra-light PET bottle has a thread diameter of 32 millimetres, yet its weight has been reduced to a mere 20 grams – an achievement for which the company received the World Beverage Innovation Award 2015 in the category of the Best Environmental Sustainability Initiative. Conventional bottles usually weigh two grams more. If, say, the production volume is 50 million bottles per year, then this new KHS bottle produces some significant economic benefit, saving as much as EUR 140,000 each year.