Discovering the unused potential of secondary materials

From the viewpoint of circular economy, a large share of products would still need improvements, particularly as regards the choice of materials and the case of residues. We also need to change our way of thinking and we need more information in order to leverage the unused potential of secondary materials.

Trends affect the product cycle

In its report “Circular by Design”[1], the European Environment Agency[2] examined the impact of product trends on product cycles. The report highlights a positive trend, modular design, which extends the life cycle of products with the help of easy remanufacturing and repairability. Other trends that support circular economy include the services developed around products and shared use, such as making the use of products more efficient.

The development of circular economy is slowed down by complex product design and increased functionality. On the other hand, functional materials may make the use of materials more efficient, but, generally speaking, heterogeneous and complex materials are difficult to reuse and recycle, especially if actions after end-of-life are not designed properly. In other words, increasing complexity and functionality hamper the cycling of materials.

3-D printing, the Internet of Things and the development of markets for recycling are examples of “hot” developing trends, the impacts of which still remain unclear from the viewpoint of circular economy: each one of the above-mentioned trends contains both positive and challenging factors:

  • 3-D printing, or other additive manufacturing technologies, enable local production and improve material efficiency, but, on the other hand, high level of customisation may make the shared use of the products involved more difficult, and the use of many materials in products can negatively impact their recyclability.
  • The Internet of Things (IoT) enables such functions as product tracking and product information management, but may contribute to increasing product complexity and use of critical product materials.
  • The markets for recycling support business models related to recycling, but focusing all resources on recycling may reduce incentives for remanufacture and reuse of products and materials.

Let us not forget the secondary raw materials

In addition to the trends described above, it is good to recognise the potential of secondary materials.

There is no general definition for secondary raw materials, but they typically include waste materials (e.g. mine tailings), side streams (e.g. slag and ashes), processing residues, material removed during product life cycle, and the products and their materials that have reached the end of their life cycle.

Waste-free production is not always possible, since the current production processes generate waste or side products, and the product life cycle is not necessarily very long. The large volume of waste material generated beside our actual product may come as a surprise to many. An example: according to report “Growth within: a circular economy vision for a competitive Europe”[3], we recapture only 5 percent of the raw material value after the first use cycle. Are we really going to forget these lost materials? When discussing sustainability and climate, the focus is often on gaseous air emissions. But what about the solid “emissions”?

Should we change our conception of such “waste material” and, from this point forward, start calling it raw material or material instead of waste?

Should we raise the bar higher? In addition to using secondary materials for such purposes as soil improvement, road construction and filler material, we could aim for high-added value materials and products given an equal status alongside primary materials.

The idea about using and utilising waste materials for functional purposes in particular is good, but there are still major challenges in making that happen, and also concerns such as potential hazardous substances.

The utilisation of secondary materials requires openness, a change in our way of thinking, research and development, scientific competence and pilot production lines. And even more important, contributing factors include enthusiasm, commitment, securing safety sufficient competence and the ability to see the potential of new initiatives in terms of business development both within industry and research.

In addition to idea generation and technical challenges, we are also facing challenges related to ways of thinking, trust, openness, value chain co-operation, markets, legislation and taxation, and getting them solved depends on our common will to do so.

Material science in CloseLoop project

At VTT, we study and develop solutions for circular economy and design strategies for circular products in the CloseLoop[4] project of the Strategic Research Council of the Academy of Finland. We seek, for example, a high-temperature-resistant material, an electroconductive material and a porous ceramic material processed out of secondary raw materials. We aim at finding such solutions utilizing aluminium industry side streams, waste electrical and electronic equipment residues, and other waste materials. All the applications mentioned above and the materials used for them need to have specific technical properties and be functional. We will demonstrate how customised high-added value applications can be produced using secondary materials alongside primary materials, so that, in the future, we could regard these material flows as assets.

Päivi Kivikytö-Reponen VTT

Päivi Kivikytö-Reponen
Senior Scientist
Twitter: @PaiviKivikyto





From the earth you came and to recycling you shall go!

Satu Pasanen

It is November 2013. A cemetery in Tampere is illuminated by candles on All Saints’ Day. I have come to visit the grave of a relative. As I leave, I notice a skip for collecting plastic candles. It is filled with just about everything imaginable, even heather. However, among the other junk is a fair number of twisted plastic casings once used for candles. I remember thinking how much of this waste there was and wondering what could be done with it: we can’t just take it all to landfill or burn it for energy. While pondering this issue over the weekend, I write a project proposal brimming with typos for my colleagues. I even manage to mix the words “crave” and “grave”! While the typos provide long-lasting entertainment, the actual project concept fails to catch on, despite preliminary background research showing how much plastic waste gathers at cemeteries. The recycling of plastic waste as a secondary material from consumer products has yet to gather momentum.

Each year, between 3.4 and 6.5 tonnes of plastic waste gathers in Tampere’s largest – 17-hectare – cemetery alone. Similarly, around 240–250 tonnes of memorial candles are collected each year from the Parish Union of Helsinki’s 76-hectare Honkanummi Cemetery. The Evangelical Lutheran Church in Finland has around a thousand cemeteries, but limited statistical data makes it difficult to estimate the amount of plastic waste these generate. There are also regional variations in candle traditions: estimates suggest that more memorial candles are used in eastern than western Finland. Despite this, even cautious estimates suggest that there is a huge amount of plastic waste. The plastic casing from used memorial candles still forms part of the municipal waste from cemeteries. These can be used in energy production if there is a local waste burning plant.

Plastic forms a large part of mixed waste

The packaging industry is the largest part of the European plastics sector, accounting for 39.5% (in 2014) of all sectors in which plastic is used. It is no surprise then that most plastic in mixed waste consists of packaging materials, such as various grades of polyethylene (PE) and polypropylene (PP). According to a recycling pilot carried out by waste management company Pirkanmaa Jätehuolto in 2014, plastic accounted for an average of 18% of mixed waste by weight (wt%). This means 32kg of plastic waste per person per year. A sorting study by the Helsinki Region Environmental Services Authority (HSY) in 2015 found that plastic accounted for around 16 wt% of mixed waste, or 28kg of plastic waste per person per year.

Residents of the Helsinki Metropolitan Area generated an estimated 187,000 tonnes of mixed waste in 2015, of which the plastic fraction accounted for over 30,000 tonnes. That is a lot of plastic. Are residents of the Helsinki area more environmentally aware? We shall see, based on the forthcoming new information on the share of plastic of mixedwaste in Pirkanmaa. In August to September 2016, Pirkanmaan Jätehuolto Oy is conducting a waste composition study as part of the Laatujäte (Quality Waste) project funded by the Ministry of the Environment. The aim of this project is to develop waste composition research and gain an insight into Finland’s average mixed waste production.

It is May 2015. After many twists and turns, the Relight project is under way. The decision has been taken to trial the use of plastic parts of memorial candles as secondary material in a project involving VTT Ltd, Innolux, Merocap Oy and Oy All-Plast Ab. A group of secondary school students has arrived at VTT to learn about recycling and material development, as well as to sort memorial candles collected during the winter. The yard is filled with the sound of cheerful chatter. Candles quickly find their way to the right place and the job is soon done and rewarded with financial support for the school’s camp fund. But the more important issue is what these young people learn about recycling and environmental awareness. Changing attitudes from childhood on.


Image 1. (left) Research Scientist Satu Pasanen talks to secondary school pupils from Hervanta, Tampere, about VTT’s research facilities and material research. (right) The sorting of the memorial candles by plastic material and brand was led by Research Engineer Timo Flyktman. (Images: Tommi Vuorinen)

Soon after being sorted, the candle casings are turned into plastic granules via a multi-phase process at VTT ‘s facility in Tampere The result is first-class recycled material, whose plastic component is one hundred percent collected from the cemetery. A partner creates injection-moulded design objects from the plastic (Image 2). They are amazing. It’s time for the sceptics to eat their words – dirty plastic fractions discarded by consumers have now been used as a raw material for a new product.


Image 2. (left) Secondary plastic raw material produced at VTT and (right) injection-moulded plastic objects made from such material. (Images: Satu Pasanen)

Recycle your plastic!

Minor delays notwithstanding, the recycling of plastic packaging became possible for consumers this year, due to the new packaging decree (518/2014) under the Waste Act. Recycling has already become part of consumers’ daily lives, with over 500 collection skips for plastic packaging appearing at recycling points (Image 3). Officially opened in June, Ekokem’s Circular Economy Village is now processing plastic packaging waste gathered at recycling points around Finland. The packaging recycling target is 16 wt% and will rise to 22 wt% in four years’ time.


Image 3. Skips for collecting plastic packaging waste from consumers. (Image: Satu Pasanen)

Plastic is ideal for recycling. From the materials development perspective, the production of secondary materials and new applications is successful when we understand the characteristics of different grades of plastic, the purity criteria of various applications, and the required physical properties. Of course, we cannot forget about the role played by price and values. The most sought-after type is the cleanest possible plastic film waste containing only one type of plastic, which is ideal for – say – injection-moulded goods ranging from tubs to design products. Although the R&D associated with this sounds simple, time and formidable expertise are needed to develop the plastic materials and applications. Such time and expertise are available at VTT.

From oil to plastic and from plastic to energy

Around 4–6% of the world’s oil production is used to make plastic. Around 311 million tonnes (Mt) of plastic raw material is created from this oil (the 2014 figure does not include fibres). European plastics production accounts for 59 Mt of this amount. European consumers generated 25.8 Mt of plastic waste in 2014 (Image 4). Of this, a third ended up in recycling, a third went to landfill and the rest was burned to produce energy. Around a hundred million barrels of oil were needed to produce the 7.9 Mt of plastic waste which ended up as landfill. From the earth you came, and society wants you to return to the earth – from oil to plastic and from plastic to oil. But this process – of biodegradation in geological time – takes too long: the dumped plastic waste could have been utilized. Around 7.7 Mt of plastic was recycled.


Image 4. Breakdown of plastic waste created by consumers by type of end-use (information source:

However, the amount of recycled plastic has grown steadily in Europe over the last ten years. On the other hand, a significant amount of plastic waste still ends up in landfill in many countries. Our western neighbour, Sweden, whose restrictions – dating back to 2005 – on the amount of plastic ending up in landfill have succeeded in lowering the dumped amount to 10%, sets an excellent example of making good use of waste. Almost half of municipal waste (about 2.2 Mt) in Sweden ends up in energy production. Energy production from plastic came to Pirkanmaa in 2016, in the form of a power plant opened in Tampere by the energy firm, Tammervoima, which uses waste as fuel.

It is August 2016 The cemetery looks beautiful, with the last summer flowers still blooming among the graves. I pay my respects to my deceased relative and take a look at the skip for plastic candles (Image 5) on my way back to my car. It is still full of all kinds of rubbish. I sigh, perhaps partly in relief and partly in disappointment: secondary materials are already a reality, even if there is still a long way to go in terms of recycling plastic. But much more time will be needed to change attitudes.


Image 5. Collection skip for plastic from candles in the Kalevankangas cemetery in Tampere 13 August 2016. (Images: Satu Pasanen)

Satu Pasanen, Research Scientist

The sources of this blog include various Parish unions, the church’s central administration, and oral and written information on waste management, as well as material on the plastics industry published by the PlasticsEurope Association of Plastics Manufacturers (Plastics – The Facts 2015) and material on the energy industry published by the Pöyry Management Consulting Oy (”Jätteiden energiahyödyntäminen Suomessa”).