Level crossing panels including recycled GRP and phenolics from car parts. (Picture courtesy of Reprocover.)
Level crossing panels including recycled GRP and phenolics from car parts. (Picture courtesy of Reprocover.)

Part 1 of this article listed commercial and near-commerical operations for recycling composite materials, and presented the story of ELG Carbon Fibre. Part 2 outlines the activities of Reprocover and discusses future developments in recycling composites.
 

Reprocover: Recyling fibreglass into useful products

“Ludo Debergh is an inventor,” says Philip van Caenegem, who took over Belgian company Reprocover from Debergh in 2013. “He is triggered by things that do not work.”

He went on to describe the way in which Debergh, already in his sixties, took on the challenge of finding a solution for recycling fibreglass and thermosets into cost-effective products. After selling his construction company, Debergh chose not to take a nice retirement home in the Mediterranean but instead invested his money and effort in perfecting the art of grinding, mixing and pressing this waste into useful products.

The main headache in the development of the process was to mix and press the dry mixture with the resin chemicals before the resin hardened. Debergh developed no less than 26 prototypes before creating a mixer which combines granules, glass fibre and resins into a slurry in just 1 minute, ready to be pressed in a mould. Reprocover filed a patent application for this remarkable mixer.

Reprocover started production in 2011 with manhole covers.

Debergh says: “Glass fibre plays a key role in Reprocover products, bringing high rigidity and outstanding load resistance. As an example, our 315 mm diameter manhole can easily withstand a heavy pressure load without damage. Working with 90% recycled materials can reduce the cost of existing cast iron solutions by a factor of five while providing much superior adhesion to asphalt and concrete.”

The first customers were the Flemish Water Company and then the cities and towns of Liège, Namur, Bilzen and Landen who ordered planters, ashtray bins and mailboxes

The Reprocover process

In its factory in Henri-Chappelle in Belgium, Reprocover break, grind and sieve thermoset industrial waste into 6 mm granules. They can take thermosets with or without fibre reinforcement. A similar recycling process is carried out on dry glass fibre waste. These are mixed with each other in a ratio of approx. 30% of glass fibre flakes to 70% thermoset granules. The dry mixture is then mixed with polyols and isocyanate (at 8-10%) and poured out into moulds and pressed under 200 tonne presses, triggering off a chemical reaction (cold pressure process) whereby the chemicals polymerise into a polyurethane resin, binding the granules and glass fibre flakes.

The result is a very hard and strong material which is resistant to fire, extreme temperature variations, UV and chemicals. It does not corrode, has good slip resistance and is lightweight.

The material is 100% closed loop recyclable in the same process, as the thermoset resins do not lose strength when recycled over and over again as thermoplastics do.

Ludo Debergh invested €6 million in capital in Reprocover, in addition to further investment from other sources. The company is on track to break even by the end of 2015. They charge a gate fee to take waste that would otherwise go to landfill.

One of their major lines now is cable duct covers. The Reprocover product is about half the weight or the concrete equivalent, so just one man can lift and install the cover rather than two. It also eliminates the problem of a loss in transit of 5-15% of the concrete covers as they are so brittle.

Reprocover will take waste from manufacturers directly or through waste management companies for a fee which varies depending on the route. Van Caenegem noted that there are three perspectives from those who have waste which could be recycled. Many are happy for their waste to be recycled as long as it doesn’t cost them more than sending it to landfill. For some, there is value to the company to see their waste recycled and so they are willing to pay more than the cost of landfill. Others see the waste as a resource and expect to pay less than the disposal cost to share in the value that is being realised by re-using the waste.

An example of the second perspective is from a company which makes polyurethane safety shoes. Reprocover can recycle the used shoes into street furniture. Recently this company has won two contracts because they were able to argue that their shoes were recyclable. There are several markets where the use of 'non-recyclable' materials is under threat or has already diminished, so in these cases, recycling is much more valuable.

The first challenge of building this business was to find a solution and some initial markets where products could be accepted and quality standards met. Then the company needed to go through the transition from starter to industrial phase. The investment to achieve this had to be found. Now they are in the phase of growing the business through finding the right products at the right profit margins.

A great deal of investigation and testing has had to be done to identify the properties of the material in relation to potential markets. For example the material could be used to make flooring for rail freight trucks, replacing wooden floors which are expensive and susceptible to moisture. The testing to qualify the material for this is onerous, and rail companies can be difficult to penetrate, but the market is potentially very large.

They can only compete if they take advantage of specific characteristics of their material. E.g. the skid resistance gives Reprocover’s products an edge over concrete covers where people need to walk on them; inflammability is an advantage to replace rubber for rail crossings in tunnels.

“We don’t talk about waste to customers,” says van Caenegem, explaining that they develop products that are competitive with other materials regardless of the fact that they are made out of recycled materials. The bulk of the market is only interested in price and quality. The ecological element is irrelevant for procurement purposes, though recycling is considered a plus once a product is approved.

Future developments

It is interesting to see that all the processes which have achieved commercial status for recycling carbon fibre are based on pyrolysis. The companies active in this area seem to be focussing more on higher value products such as mats and preforms, to complement the chopped and milled fibre markets. The University of Nottingham, UK, continues to work on their fluidised bed process, working with sponsorship from Boeing. This is interesting because this process may provide fibres that are cleaner and easier to reprocess than those from pyrolysis.

There are at least 6 groups which are researching or have researched solvolysis based processes for carbon fibre, which can gain more value from the resin chemicals in the waste, but none of these seems to be close to commercialisation at this point in time.

Thermochemical processes have also been developed for GRP and three have been reported publicly in recent years. Heibei KNT was reported in January to have a recycling line under construction in Jizhou City, China. This is due to use a high temperature cracking and low temperature catalytic separation process to re-use glass fibre for functional parts or as high-temperature ground milled fibre. Resin products could be used as heavy fuel oil or refined to produce chemical raw materials. (This has not been included in the table as no further information is available.) Panasonic Electric Works Co Ltd built a pilot plant in Japan in 2009 able to treat 400 kgs per batch, but is not near to commercialisation now. SINTEF in Norway developed a process, but it does not appear to have been brought to market.

It will be interesting to see if these can be fully commercialised on an economic basis. One factor is that when glass fibre loses its size (as is the case with a thermal or chemical process), it also loses most of its strength. Strathclyde University, Scotland, has developed a process to regenerate the strength of thermally recycled glass fibre and is actively seeking partners to develop this, so perhaps this will provide a solution which can compete with virgin chopped glass fibres.

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There is also continued interest in using ground GRP recyclate either in thermoplastics or in construction products with a thermoset binder. Reprocover are already successful in the latter. The Ecopolycrete material is another example, and Global Composites Recycling Solutions expect to be up and running before the end of the year in the USA and UK. Progress by Hambleside Danelaw and Extreme EcoSolutions may also find ways to gain more value from GRP waste than using it as cement feedstock, though Zajons are providing a useful alternative to landfill in the meantime with the cement kiln method.

The Båtskroten project in Sweden intends to take whole boats, recycle/re-use spare parts, and then recycle the GRP hulls. Båtskroten is an initiative with Stena Recycling to develop a process and a network for boat scrapping, hoping to start actively in the second half of 2015.

The trend is to seek higher value from recyclate, while balancing that against processing costs. The economic struggles of recent years slowed development for some companies, but now that we are seeing recovery and a high growth rate in the composites industry, the opportunities and the need for recycling will increase. ♦

About the author

Stella Job is a freelance consultant in the composites sector and works part time as Supply Chain and Environment Officer for the UK trade association Composites UK.
 


This article was published in the September/October 2014 issue of Reinforced Plastics magazine. The digital edition of Reinforced Plastics is distributed free of charge to readers who meet our qualifying criteria. You can apply to receive your free copy by completing this short registration form.