How green is the material world?

METALS

The metal can has been a familiar sight on supermarket shelves for decades. Metal is a renewable material and infinitely recyclable without a loss of quality. According to the Metal Packaging Manufacturers Association (MPMA) there is no single figure on how metal operates in a material-to-material loop, but for every can recycled, a measurable amount of virgin material is saved. “The higher the recycling rate for metal, the lower the carbon emissions,” director Nick Mullen says. Recycling cuts emissions by up to 75% for steel and 95% for aluminium.

“Metal’s inherent robustness provides essential protection during transportation so absolute minimal secondary packaging is required. The metal packaging industry has invested in constant and continuous lightweighting and has reduced weight by 35% over the past 20 years,” he adds.

The lifespan of the product inside the can is good, with a minimum shelf life of three years. It can be printed on directly or labels can be used. According to the MPMA, metal has the highest recycling rates of any packaging material in Europe.

GLASS
It may not always get the thumbs-up for being the most lightweight of packaging materials but glass still remains the preferred choice of many brand owners, attracted by its strength and clean hygienic appearance.

The raw materials in glass, consisting of cullet, sand, limestone and soda ash, make it highly sustainable and prices don’t suffer from the market volatility of oil-based products. 

Glass manufacture is energy intensive, but British Glass director general David Workman argues that it is no different to any other raw material. “We are an energy-intensive industry and we don’t run away from that, but glass is 100% recyclable and the process can be repeated forever. It is totally inert in use and post-use, doesn’t degrade and is not harmful to the environment.”

While glass is heavier to transport, its strength enables pallets to be stacked to maximise space.

CARTONBOARD
Ultimately, cartonboard is a renewable resource, with 80% of timber used coming from sustainable European forests. According to ProCarton, cartonboard is a versatile low-cost manufacturing option, allowing brand owners to respond quickly to promotions, as conversion is relatively easy.

Cartonboard is either purchased in sheets or reels, depending on the requirements of the printing or conversion processes. This form of packaging material also boasts the ability to be flat packed for transit, ensuring an efficient use of space. It can then be opened up on the filling line. The energy used to process wood in the paper and board industry is derived from the non-cellulose constituents of the wood and so is naturally renewable.

Industry body ProCarton says emission risks in processing and use have been significantly reduced to low levels. ProPak head of public affairs Jennifer Buhaenko says: “Cartons can be recycled, composted or their inherent, non-fossil-based energy can be recovered. Cartons consume less energy in manufacture and use and are recyclable as fibre, compost or by energy recovery.”

COMPOSITE POUCHES
Aluminium is the third most widely available element in the earth’s crust. The European Aluminium Foil Association (EAFA) highlights that although the energy required to produce primary aluminium is high, to recycle the metal only takes 5% of the original energy investment. The quality of the re-melted aluminium is as high as the new metal.

According to the EAFA, the lightweight qualities of composite pouches can mean substantial transport cost savings. The packaging laminate is delivered in space-saving reel form, again reducing transport costs.

Also, when comparing a truckload of standard 200ml glass packs of a drink product compared to the same product packed in 200ml alufoil pouches, over 80% more product can be shipped in the same space when using the pouch packs. EAFA states that independent studies, checked by the German Environment Agency (UBA), concluded the stand-up pouch is an environmentally friendly beverage pack with a similar environmental impact to a returnable glass bottle or liquid carton.

FLEXIBLE PLASTICS

The Packaging and Films Association (PAFA) argues that plastic film products make the best possible use of by-products of the oil refining process (ethylene and naphtha), which might otherwise have been wasted.

As long as oil is extracted for fuel, energy, heating and industrial uses it can also be turned into flexible plastic.

Plastic film laminates offer big weight saving and resource reduction, according to PAFA, for goods like fresh ground coffee. Reportedly, without using flexible plastic packaging, a retailer’s vehicle fleet would make 50% more journeys.

On the negative side, flexible plastic wrappings can often be too lightweight to viably collect for recycling, although a PAFA spokesman suggests this could change in the future. “Government and local authorities set recycling targets based on weight and because this kind of plastic is the lightest type of packaging the authorities do not want to collect it. It is almost being punished for being lightweight.” He admits that there is quite a lot of work to do in gaining public approval. “Flexible plastic was recently taken off a leading retailer’s cucumbers – without the 1.5g of plastic wrapping on a cucumber, the product would be unsaleable after three days, due to moisture loss.”

BIOPLASTICS
Bioplastics are derived from plants and can be grown again and again. They also widen the waste disposal options for plastics to include composting or anaerobic digestion.

The National Non-Food Crops Centre says that new plants can absorb carbon that has been released through the production and use of bioplastics, so they are part of a closed loop. It also states that life-cycle assessment has shown that NatureWorks PLA, for example, uses 62-68% less fossil fuel in production than traditional materials such as PET, PS and PP. Bioplastics are currently manufactured on a smaller scale than petrochemical plastics so they do cost more, but as the market develops the price could fall. Plus, some bioplastics have added-value features such as breathability or compostability.

Bioplastics are no heavier than petrochemical plastics and can be printed on directly or have labels applied depending on the material used. In certain applications, such as fresh-food packaging, bioplastics can enhance the product’s lifespan compared to using petrochemical plastics. European Bioplastics chairman Harald Kab says: “The main driver is performance. The material can be more expensive, but bioplastics can offer longer shelf life. Bioplastics are not going to be able to fulfil all purposes but the whole world has to look at carbon management.”

LIQUID CARTONS
Beverage cartons are, on average, made from 75% wood fibre and, according to the Alliance for Beverage Cartons and the Environment (ACE), in the Nordic forests where the majority of trees going into carton manufacture are grown, annual tree growth exceeds annual felling.

ACE says, however, that it is difficult to quote the carbon footprint of cartons because the value can vary depending on size, format and country. An indicative carbon footprint for a one-litre aseptic carton is about 70g, including disposal or recycling.

Before filling, cartons are either distributed in reel or blank-fed format – making the most of space in transport. After filling, their shape and average stackability of five to eight cartons reduces the number of trucks needed. The design is printed directly on to the carton and brand owners can make use of the 360-degree printable surface of cartons.

Shelf life varies between product types and long-life cartons are designed to store the product from six months up to two years. Beverage cartons are also in the ‘widely recycled’ category of the BRC labelling system. ACE chairman and Tetra Pak environment manager Richard Hands comments: “We have dramatically extended the UK’s carton collection infrastructure, from 20-90% of local authorities. Driving the collection rate upwards – and, importantly, getting recycling information to consumers – remains a high priority for us.”

RIGID PLASTICS

Plastics materials based on an energy source such as oil and gas use about 4% of the barrel of oil, according the British Plastics Federation (BPF), and coverting these into packaging is not especially energy intensive.

BPF public and industrial affairs director Philip Law says the potential to recycle plastics or generate energy from the used plastics through incineration provides a positive life-cycle story.

So how expensive is it to produce? “We prefer to talk about the value of the ‘material’,” Law says. “The value to a customer of finding a solution to a problem shapes the price he is prepared to pay.”

A major advantage of plastic products is their light weight and high strength qualities. This means transport carrying plastic packaging requires less fuel, resulting in lower levels of emissions.

All plastics can be recycled from a technical point of view and it is estimated that plastic materials can be recycled anything up to six to 10 times before the quality degrades too much. However, many types of plastic are not widely collected for recycling. In addition, some plastics packaging products are not collected for recycling because they are too small or they are too mixed up with other materials, or contaminated with food residue or household chemicals.

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