Topic of the Month May 2016

Plenty of potential for recycling

Source: istock / yaruta

Technologically, plastics recycling is not a problem at all today. In-house recycling has now become established right across industry. For plastics processors who work with pure-grade raw materials, the waste-free factory has become commonplace. And for post-consumer wastes, there are increasingly mature reutilisation strategies, enabling the regranulate produced with them to substitute virgin material without problem. In the last few years particularly, there has been fast-growing demand for recompounds, pigmented and/or reinforced granulates produced entirely from residues. All the same, the industry still has a number of hurdles to take and problems to solve. Profitability, optimised collection strategies, political targets, consumer interests and education, and the design of recyclable plastics products are just some of the core themes.

Butadiene and isoprene: important intermediates in plastics production

Roughly 125,000 tonnes of PVC wastes, including window profiles, are recycled each year in Europe. The regenerated material can be used without difficulty for the production of articles for the construction sector such as profiles and pipes. Image: Rewindo

According to PlasticsEurope, the association of plastics producers, the 1.45 million employees in the European plastics industry in 2014 were working for 62,000 mainly small and medium-size companies that generated total sales of EUR 350 billion. Plastics consumption in the European industry as a whole came to 47.8 million tonnes, with about half, amounting to 25.8 million tonnes, being collected after use. PlasticsEurope investigated the collection rates in the 28 EU states plus Norway and Switzerland and found that there is still strong variation.

Although a ban on the landfilling of plastics residuals has meanwhile been announced in nine countries – Austria, Belgium, Denmark, Germany, Luxemburg, the Netherlands, Norway, Sweden and Switzerland – the proportion going to landfill in the other countries is still very high at as much as 70 per cent. The countries with the highest landfill shares are Bulgaria, Croatia, Cyprus, Greece and Malta. What is compared here is the share of plastics residuals landfilled as against the residuals that are reutilised, i.e. incinerated for their energy content or recycled. Overall, of the total collected residuals in Europe, about two thirds are now reutilised, while 30.8 per cent are landfilled. Of the plastics residuals that are reutilised, about half – 7.7 million tonnes – is recycled and the rest is incinerated to generate energy. The goal must be to significantly reduce the quantity of landfilled plastics in the coming years and to reutilise more. PlasticsEurope likens the quantity of some 8 million tonnes of plastics that are currently still landfilled Europe-wide to a volume of 800 Eiffel Towers. Experts are therefore demanding more concrete political targets in all European countries, educating consumers better to adopt a more sustainable attitude towards plastics as a resource, and the introduction of improved, nationwide collection and sorting systems.

The goal must be to significantly reduce the quantity of landfilled plastics in the coming years and to reutilise more. PlasticsEurope likens the quantity of some 8 million tonnes of plastics that are currently still landfilled Europe-wide to a volume of 800 Eiffel Towers. Experts are therefore demanding more concrete political targets in all European countries, educating consumers better to adopt a more sustainable attitude towards plastics as a resource, and the introduction of improved, nationwide collection and sorting systems.

The main fractions are polyolefins

With about 9.5 million tonnes of PP, 8 million tonnes of PE-LD and PE-LLD and 6 million tonnes of PE-HD and PE-MD, polyolefins are by quantity the plastics most used in Europe, collectively accounting for about half of overall consumption. Because of their quantity and many fields of application, polyolefins account for the lion’s share in the recycling streams as well.

Trenntechnik Ulm GmbH has installed a line specifically for the chemical separation of PA/PE composite films in Memmingen. Using this method and a suitable solvent, it will be possible to recover other raw materials as well. Image: Trenntechnik Ulm

If these are pure-grade residues, they can be efficiently processed, so there are numerous recycling businesses devoted to polyolefin recycling. Some plastics processors are even going a step further and, in addition to in-house recovery and the direct recycling of their production wastes, operate their own regranulators to produce granulate from their wastes. One such firm is Polifilm Extrusion GmbH in Weissandt-Gölzau which generates 25,000 tonnes of regranulate per year, enabling it to produce bin liners and construction and agricultural sheeting more profitably.

The situation is more complicated when PE and PP are mixed, as they are very hard to separate because of their similar density, and NIR sorting processes are today state of the art. However, PE and PP can also be processed together into high-grade products, as mtm plastics GmbH in Niedergebra demonstrates with its PE/PP regranulate. DSD Resource GmbH in Cologne specialises in the processing of the pure PP fraction. “We rely on a defined, reproducible starting blend so that we can produce defined, reproducible regranulate in attractive colours,” explains Managing Director Dr Michael Heyde.

PET recycling established but with room for expansion

PET, most of which is used for the production of bottles, accounts for almost 7 per cent of total plastics consumption per year in Europe or about 3.1 million tonnes. Overall, the 30 countries of Europe achieve an average collection rate of 57 per cent. In 2014, for example, 1.75 million tonnes of post-consumer PET wastes were collected. Here, again, the collection rates vary greatly. While Germany, Italy and Switzerland collect about half of the total volume, some countries achieve a collection rate of only 10 to 20 per cent. The PET sector is enjoying rising collection rates overall, which, according to PCI PET Packaging, Resins & Recycling Ltd., should increase by a further 3 to 5 per cent per year by 2019.

For many products, such as bin liners, it has already become commonplace today to use recyclate. This makes good economic and ecological sense. Image: Polifilm

However, it is almost exclusively bottles that are collected, usually in dedicated collection schemes. Although it was originally the goal to return the collected bottle flakes to bottle production, the industry has sought and found customers in other areas. For film/sheet manufacturers, post-consumer bottle flakes have become increasingly interesting, and in 2014 they used the biggest share – 34 per cent – of the collected residuals in their branch of industry. Almost 30 per cent of the flakes were used in blow moulding applications, 26 per cent in the fibre industry and the rest for packing straps and other products.

“Production of the regranulate required in injection moulding applications for the production of new bottles for food or non-food contact is currently low because of the sharp drop in the price of virgin material,” explains Elfriede Hell, Head of Recycling Technology at Austrian plant manufacturer Starlinger. Unlike used bottles, post-consumer trays and films usually end up being incinerated for energy or even on landfills. “But things have recently been changing. We have a number of customers interested specifically in projects for recycling trays and films,” Hell stresses, convinced that the strong demand for PET packages will continue as their glossy and stylish appearance meets the needs of consumers and marketers perfectly.

Werner & Mertz GmbH in Germany has become the first company to recycle non-deposit PET bottles and films/sheet from collected packaging waste. As part of its recycling drive, the company has produced regranulate for use in detergent bottles out of PET wastes. However, here again they are only able to process a small proportion of the films/sheet.

PVC recycling achieves high utilisation rates

The recycling of PVC, a material whose outstanding mechanical properties have made it indispensable – particularly in the building sector, where it has a 70 per cent share, but also in the packaging, furniture and medical technology segments – has developed very encouragingly in the last few years. According to a Consultic study commissioned by PlasticsEurope, the demand for PVC in Europe came to 4.9 million tonnes in 2014, making it the third most used plastic after PP and PE.

Injection mouldings producer Gies GmbH & Co. Kunststoffwerk KG in Niederaula produces coloured shopping baskets using nothing but PP regranulate from DSD Resource GmbH in Cologne. What makes this regranulate special is its reproducibility and amenability to colouration. Image: DSD

Germany accounts for 1.56 million tonnes of this, or roughly a third of total demand. Since PVC is often employed in very durable products like windows, pipes and floorcoverings, “only” 650,000 tonnes are available for reutilisation each year, with about 520,000 tonnes of this coming from post-consumer applications and 130,000 tonnes being industrial wastes. The reutilisation rate for PVC wastes is 99 per cent, with only 1 per cent being disposed of. Of the 99 per cent that is reutilised, 62 per cent, i.e. 396,000 tonnes, is used for energy recovery and the rest is recycled. The recycled PVC generated in this way is put to use particularly in building applications, e.g. in new profiles and pipes, as well as in horticulture and agriculture. “Our sector has been concerned with the recycling of PVC for over 25 years, so we already have a very well developed network today,” says Thomas Hülsmann, Managing Director of Arbeitsgemeinschaft PVC und Umwelt e.V., Bonn. At www.pvcrecyclingfinder.de, many PVC-processing companies are listed. Just how important recycling is for the sector is expressed by the European voluntary commitment that is supported by the leading plastics associations. In the most recent voluntary commitment “VinylPlus”, the companies of the sector undertake to reutilise 800,000 tonnes of wastes for recycling and energy recovery by 2020. This demonstrates the forward-looking and sustainable position adopted by the sector, Hülsmann adds.

Composites are often unsuitable for recycling

While post-consumer products made of pure polymers lend themselves well to reprocessing, the situation for composite products consisting of two or more raw materials is entirely different. These wastes are in most cases unsuitable for recycling. Dr Michael Scriba, mtm-plastics Managing Director and member of Plastics Recyclers Europe (PRE) and of Bundesverband Sekundärrohstoffe und Entsorgung [Federation for Secondary Resources and Disposal] (bvse), is therefore calling for the recycling-friendly design of the packages that contribute a large proportion of post-consumer wastes. With the aid of the RecyClass (www.recyclass.eu) programme, any manufacturer of plastics packages can quickly and easily check whether his package is recycling-friendly. Here it is particularly important to dispense with fillers like chalk in PE and PP packages as far as possible, avoid plastics-paper composites, use pigmentation in moderation and make sure that the density of all products is well clear of 1 g/cm³ so that separation on the basis of density is possible.

At the same time, efforts are being made in the industry to develop reutilisation strategies for mixed wastes. Trenntechnik Ulm GmbH is pursuing a very exciting approach here in developing a chemical separation process for PE/PA composite films and building a unique production plant with a capacity of 10 tonnes per day. The end products of the separation process are a polyamide comparable with virgin material and a polyethylene that is pigmented directly with soot, i.e. a carbon black master batch in a particularly pure form. As stressed by Managing Director Wolfgang Zacherle, there is a suitable solvent and separation agent for every plastics composite, so there are no obstacles to an extension of this process to other composite products.

Summary

Although recycling is a much-discussed topic today and is also very much alive in many projects in the plastics industry, experts are repeatedly confirming that, by comparison with other sectors, too little waste material is used instead of virgin material. Across Europe, 50 per cent of metal scrap is returned to the steelmaking process, and the same applies to the paper industry, where 50 per cent of old paper and board is used in the production of new paper and board. For glass, at 33 per cent, the figure is a little lower, but still very high compared to the quantities that are recycled in the plastics sector.

For the extrusion blow-moulded dishwashing detergent bottle made of polyethylene, Ecover Belgium N.V., manufacturer of ecological cleaning agents, uses plastic wastes gathered by fisherman from the sea. Image: Ecover

For in the plastics sector, only about 4 per cent of reprocessed waste plastics are used instead of virgin material in the fabrication of plastics products. The plastics sector is of course a young industry overall. Plastics only became widespread in the 1950s, and reutilisation strategies for waste plastics were only introduced in 1990s, yet both the collection systems and technical feasibility have developed enormously in the intervening period. Anyone wishing to find out about these new technical solutions can do so at K 2016, the world’s No. 1 trade fair for the plastics and rubber industry, from 19 to 26 October in Düsseldorf. Numerous exhibitors are presenting machines and plant for processing and recycling, for pure-grade wastes as well as for mixed wastes and wastes of rubber.

It can therefore be assumed that recycling rates will continue to rise in the years to come, as there is strong demand for recyclate for both environmental and economic reasons. Marine litter, i.e. the pollution of the seas with wastes, has internationally highlighted the irresponsible treatment of wastes particularly in newly industrialised countries and lent added strength to the demands of other consumers for the sustainable treatment of resources. Model projects like the Ocean Bottle are not only very interesting examples, but also help to raise awareness of the subject among the general public and, above all, consumers. For the production of this Ocean Bottle, Ecover Belgium N.V. enlisted the services of fishermen in Britain, France and Belgium to collect bottles from the sea. 10 tonnes of waste was accumulated within a year, and the PE fraction from this was recycled into new PE dishwashing detergent bottles.

(Editor: Guido Deussing)