Ab Kasper
European Composites Industry Association (EuCIA)

Ask me about:
Environmental and occupational exposure related aspects in the composites industry.

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Q: Are there any bio-epoxy or bio-resins available on the market? How are their properties affected compared with usual epoxy systems? More generally I am interested in knowing about 'environmentally-friendly' epoxy resins.

A: The commonly available epoxy resins and unsaturated polyester resins are based on raw materials originating from mineral oil sources. At the moment there is a strong tendency to develop these resins, at least partly, on a more sustainable raw material base. Various routes are being explored at the moment. Two important routes are the following: the use of furane based raw materials and the use of chemically modified soy bean oil and linseed oil as raw material base. To my knowledge this has not yet resulted in a complete replacement of the raw materials by 'green raw materials.'
However, UP resins are on the market in which part of the raw materials are based on soybean oil. These resins are marketed by Ashland.
For more information the following links could also be explored:
Wageningen University, the Netherlands;
Bangor University, UK;
Trans Furan Chemicals, Belgium.

Q: Can glass fibres from fibre glass composites be separated from the composite without grinding the fibre?

A: The commonly used way to recycle composite materials is by grinding the material and subsequently separating the fibres from the cured resin matrix and the fillers. The type of grinding equipment determines to a large extent the appearance of the remaining fibres. Inevitably in these processes a part of the glass fibre will be broken down to smaller particles.
Other ways to separate the glass fibre from the resin matrix have been studied extensively, such as heat treatment and back-to-feedstock processes. Thus far these methods have not proven to be commercially viable.

Q. Where can I find sound advice regarding industry best practice for health and safety relating to GRP hand lay manufacturing? I am aware of CoSHH, risk assessments etc but have little knowledge on this manufacturing process.

A. EuCIA and the UP Resin Group of Plastics Europe have issued a series of Safe Handling Guides for working with unsaturated polyester resins. These can be found at the following link:
http://www.plasticseurope.org/Content/Default.asp?PageID=1081

Recycling

Q. Can composites be recycled?

A. Yes, composites can be recycled. A distinction should be made between thermoplastic composites and thermoset composites.

Q. How can thermoplastic composites be recycled?

A. Thermoplastic composites are recycled by grinding finished parts into small particles. These particles can be fed again into an injection moulding machine together with virgin thermoplastic composite materials.

Q. Can thermoset composites be recycled?

A. Thermoset composites can also be recycled. Contrary to thermoplastic composites, the resin part of the composite cannot be reshaped again by heating. Thermoset composites are therefore ground in special equipment where the reinforcing fibres are separated from the resin and filler part. The fibres can be reused as reinforcing material in other applications; the resin and filler part is used again as filler in many other applications.

Q. How can glass fibre (fabric, mat etc) be recycled?

A. Clean long glass fibre is recycled in concrete compounds preventing shrinkage and cracks. By cutting it into short fibre lengths, these milled fibres are used in thermoplastic composites.

Q. Can carbon fibre (fabric, prepreg etc) be recycled?

A. A process to recycle clean uncured carbon fibre as well as carbon fibre prepreg and cured materials has been developed in the UK recently. For more information go to http://www.milledcarbon.com/

Q. Are there any commercial composites recycling systems in operation now?

A. Yes, In France, in Tournon, 100 km south of Lyon, the company MCR, Mixtes Composites Recycling, a subsidiary of the car part manufacturer Inoplast, produces composite compounds and has a recycling workshop for composite waste and end of life vehicle (ELV) parts.  

Q. What needs to be done to develop these systems?

A. Technically, developments are ongoing to enhance the performance of the grinding and sieving process in order to produce more grades for different applications and to increase its technical properties.
Commercially, a lot of efforts are put in the market introduction of the recycled powder and fibre fractions. Industries, not normally involved yet in the composite business have to convinced of the advantages of their uses. In the concrete industry the recycled fibre is cheaper than the current fibre.

Q. Where can people go for more detailed information about recycling of composite materials and components?

A. In Europe the ECRC (European Composites Recycling Company) is setting up a closed loop system to recycle thermoset composite materials. For more information go to http://www.ecrc-greenlabel.org/

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