More Sustainable Beverage Packaging is on the Horizon

Image courtesy of Victor Martianov via Unsplash

PET or glass bottle, aluminum can, beverage carton or maybe even a paper bottle, single use or multiple use—there is a huge range of choices for beverage packaging. But which is the most sustainable? Ecological aspects have also become increasingly important here in recent years. And not only for packaging material: These aspects have also become important for filling and actual packaging processes.

Some beverages simply come with classic packaging. We usually buy beer or wine in a glass bottle, milk in a carton and soft drinks in a PET bottle. Over the last few years, however, customers have become more critical and sustainability issues have become increasingly important in the beverage sector. Plastics especially have a bad reputation. After all, how well a package ultimately scores in the lifecycle assessment depends on many factors. Experts are therefore reluctant to make sweeping recommendations.

Glass bottles are neutral in taste, but also fragile and heavy. They are more suitable for multiple uses than any other type of packaging. PET bottles, too, can be refilled several times and then recycled. They are shatterproof and notably lighter than glass bottles. Plastics, however, have had a bad reputation with customers for some time, despite its recyclability and high collection quotas. Beverages in aluminum cans still enjoy popularity, but the extraction of its raw materials and the production of cans from raw aluminum comes with a huge cost in terms of energy. So, everything comes down to the collection quota since there is no limit to the number of times the cans can be recycled. Beverage cartons are also always single use, but they are for the most part made from renewable raw materials. Improved procedures have ensure that the cardboard, aluminum and plastic components are separated. The Umweltbundesamt (German Environmental Agency) therefore classifies them as “single use packages with ecological advantages.”

Will There Be Paper Bottles?

At the end of 2016, the Carlsberg Group presented the “Green Fiber Bottle,” its prototype for a paper bottle, for the first time. In the summer of 2020, the beverage corporation Diageo announced the first paper-based spirits bottle for Scottish Johnny Walker whisky, but so far there has been no large introduction to the market. In early 2021, for the first time in Europe, Coca Cola offered a plant-based beverage in a paper bottle to 2,000 consumers in Hungary. No further steps were taken after this test offer, however.

Since the development of sustainable bottles made of fiber, work on their optimization has never ceased. The goal: a completely organic paper bottle. Currently, the “classic” paper bottle still consists of paper coated with a thin layer of PE, which, however, can be easily peeled off during the processing of waste paper, separated and then recycled. One disadvantage of polyethylene is that it doesn't work very well for carbonated beverages, and these usually require a PET coating that is a bit thicker.

The Carlsberg brewery took things a step further this year. The bottles for its large-scale consumer test are coated with PEF (polyethylene furanoate) an organic polymer with similar properties to PET. The PEF acts as a highly effective barrier between the beer and the outer hull made of fibers, protects the taste and is supposed to retain the carbonic acid of the beer better than conventional PET. The biopolymer is also both compatible with PET recycling systems and biodegradable. The current prototypes are an already improved variant which features PEF coating as well as a new bottom to improve the stability of the bottle. The brewery’s next generation of bottles are planned to be made available with a fiber-based lid and cap.

Lightweight Glass Bottle for Multiple Use

Glass is a popular packaging material for beverages. Its greatest disadvantage is only its high weight. In direct comparison, PET bottles can be as much as 90% lighter than the multiple use variety made of glass. To counter this, manufacturers of glass packaging are working on weight reduction, such as using tempered, lightweight glass. Reusable bottles produced this way are not only as much as 30% lighter than the standard variety but they are also more resistant to abrasion, which can turn them into a real alternative both economically and ecologically. However, the thermal treatment process that gives the glass its greater stability limits the possibilities of product design. Variations in wall thickness present an especially difficult challenge during this process.

Better Safety on the Road

In order for bottles, cans and beverage cartons to reach their point of sale without damage, they need proper safety measures during transportation. Usually, thin stretch wrap is used for stable packing on a pallet. For this purpose, machine manufacturers like Mosca offer strapping machines for pallets and stretch winders. Depending on the type of packaging, safety requirements for the pallet can be very different. Cans must be protected against warping and glass bottles against breaking. In order to transport lightweight, empty beverage cans they need to be held in place from the side or top and also require light pressure to be kept secure on their way to the beverage bottlers.

A new strapping machine for pallets by Mosca creates the necessary pressure on the empty cans through vertical strapping. The system uses sustainable PET straps made from recycled materials and packages/wraps up to 61 pallets per hour for transport—without wasting resources. A narrow strip of plastic is enough to secure even the heaviest pallets while the use of material and carbon footprint are kept to a minimum.

Alternatives to Plastic Shrink Wrap

Inside modern stretch winders, a reel of foil circles the pallet horizontally, while the goods—full cans or fragile bottles—remain static. Elastic stretch wrap is used often, as pre-stretching the foil increases its ability to stretch by up to 300%. Manufacturers are already working on a more sustainable solution using renewable material. For example, packaging a pallet with elastic, puncture-resistant, paper is a packaging solution that can be fully recycled.

For PET bottles, a paper-based solution that can be completely recycled has recently entered the market: a package band made from 100% craft paper that wraps around bottles, has a high tensile strength and is able to support enough weight to secure the bottles during transport. In addition, a compatible solution is a corrugated cardboard clamp that grips the bottle neck. The clamp also allows the individual bottles to be easily separated from the package.

Hygiene is a Priority

While it used to be the case that cans were primarily filled with beers and carbonated drinks, for some time now there has been a trend toward canning more sensitive products like iced teas, plant-based drinks, juices, smoothies or near-water products. This poses new hygienic challenges to beverage bottlers. The system manufacturer KHS reacted to this by partnering with Ferrum to develop the fill-and-seal block SmartCan that features optimized hygienic measures. The hygienic space inside the filler part of the block consists of raised sheathing plates on one side, and an enclosure on the other side that has a notably smaller product space around the filler carousel. Following the so-called “donut principle,” this creates a ring-shaped enclosure, reduces the volume of the hygienic space by 40% and allows an optimized and targeted jet of sterile air to stream around the sensitive zone.

Hygiene is also important for the new aseptic filling system from Sidel, which was developed for the growing market for sensitive beverages in PET bottles. The integrated stretch-blow-fill-seal solution is a further development of Aseptic Combi Predis technology, intended to help bottling companies serve the growing market for drinks with a long shelf life like juice, fruit beverages, soft drinks, isotonic drinks, tea and liquid dairy products. The demand for these products, says Sidel, is expected to reach a volume of 192 billion units by 2024, which is an increase of 44% compared to 2011. Sensitive products are said to represent 55% of the market for non-alcoholic beverages, and the predicted growth of this segment (annual growth rate of 2.3% from 2019 to 2025) is higher for PET bottles than for other materials.

Flexible Response to Demand

In terms of packaging, bottling companies today face multiple challenges, both economic and ecological. On the one hand, they are subject to pressure from growing time constraints and rising costs, on the other hand, the beverage industry is under scrutiny from legislature regarding recycling quotas and carbon emissions. Considering these developments, KHS is offering its customers a large portfolio of adjustable block solutions, especially for filling PET bottles. Among the company’s solution is a new, modular, platform that can be customized and expanded.

First used for filling glass bottles in 2020, the machines now also fulfill consumer demands for adaptability and a guaranteed future when it comes to plastic bottles. “Nobody can say which trends the industry will follow in five years,” says Manfred Härtel, product manager filling at KHS. “This is the reason we made our platform modular—so it can be fitted any time for different drinks or PET containers, depending on the demands of the market.” This way, additional components can be bought at a later time and integrated into existing solutions with a minimum of effort.

In addition, many improvements in construction already help to save energy. The new filler allows filling temperatures to rise to 24°C, which lowers the investment and maintenance costs for energy-intensive cooling technology. At these temperatures there is also no condensation of water, which would have to be dried using a lot of energy before further packaging in foil or cardboard.

“Tethered Caps” Soon to be Mandatory

Caps and valves are often a problem when it comes to littering and the recycling of plastic bottles. EU legislation is therefore making the use of closures that are permanently connected to the bottle mandatory starting in 2024. Many manufacturers have already reacted and developed so-called “tethered caps.” Beverage manufacturers are already implementing the EU directive sooner than necessary. Coca-Cola has already introduced its attached caps in 2021 and has been expanding them to an increasing number of PET single-use bottles. The opening mechanism is the same, and the cap—now attached to a safety ring—can still be moved round the neck of the bottle as desired or secured in a specific position. By January 2024, the beverage corporation aims to have successively converted all its German plants. At the end of 2021, the bottling plant in Dorsten, North Rhine-Westphalia was the first to make the change.

Manufacturers assume that the new caps will only be accepted by consumers if the handling is right. In consumer studies, a “tethered cap” by Bericap scored well because of its intuitive handling, the 180° opening and its hygienic advantages. By switching to tethered caps at an early stage, beverage suppliers can also increase the brand appeal of their products.

Intelligent Caps

United Caps and the startup Mimica have marketed a clever cap solution that includes a freshness indicator—the “touch-cap.” The cap changes its surface from smooth to uneven when a product is no longer fit for consumption. This is possible due to a gel in a special label that can change its structure. The cap can be recycled and consists of a lid base and a closing cap. This is applied after the filling process using a special machine which, like other modules for labeling or stretch wrapping, can be easily integrated into production. The consumer activates the effect by opening the lid for the first time by twisting the cap. A pilot project for the solution is already underway in the UK with an orange juice brand.

Doris Bünnagel has been working for German packaging media for over 20 years after studying natural sciences at the University of Cologne and training as a journalist at the Institute of German Business.