"The support and advice that WRAP provides has been vital to the success and progress of our used tyres research and development trial. This trial has enabled us to advance the use of ultra fine vulcanised crumb rubber that is derived from post consumer truck tyres, into a new composite roofing slate"
Ted Pederson, Technical Director at the Airport Business Centre
Trials have been undertaken of a new innovative roof tile that may give a further valuable outlet for recycled tyres and plastics as well as benefitting the construction industry.
The trial managed by the Airport Business Centre (ABC) working with Crumb Rubber Ltd (a daughter company) and Queen Mary University in London, was funded through the Waste and Resource Action Programme (WRAP).
More than 48 million tyres are disposed of each year in the UK and WRAP is taking great care to ensure that the best use is made of this potentially valuable resource.
Tyre rubber can be granulated or powdered through a grinding process. WRAP says that the development of a new ultra-fine crumb rubber having unique properties has been incorporated into the tile, opening up new product opportunities for the end uses of recycled rubber.
Crumb Rubber Ltd has a new £2.3m rubber crumbing facility in Plymouth that grinds post-consumer tyres to produce rubber granulate. The company developed the new ultra-fine 80 mesh, 177 micron crumb rubber used in this project. "The 80 mesh crumb rubber has unique properties with myriad surfaces providing greatly enhanced mechanical and chemical bonding potential", according to the research report.
The business and research partnership investigated the behaviour of various waste plastics blended with rubber powder from post-consumer tyres.
Loading used tyres (Photo: WRAP)
Mouldings produced from the plastic-rubber blends were tested to determine their properties and commercial viability in the manufacture of a new roofing tile which was to incorporate a high percentage of recycled material, thereby opening up the markets for recyclate.
Various composites of rubber, polypropylene and other fillers such as wood flower were tested to arrive at a favoured combination. Polyethylene was also tested as one component.
The final product will need to meet UK certification standards, a task that will be tackled in the commercialisation phase of this project to follow.
Following the successful outcome of the research, WRAP is now putting its weight behind standard testing to provide accreditation for its use in the marketplace. Products produced under standard testing procedures will offer benefits for the housing sector, which is under pressure to improve its operational sustainability.
Through their work, WRAP and the research partnership have offered the potential for commercialisation of the ‘green roof tiles’ and they have given housebuilders the opportunity to move towards any minimum recycled requirements that they may face.
Artificial tiles
Artificial tiles currently in production in general do not include recycled materials and are composites of plastic, rubber and other constituents. A UK example is Britslate which is produced from virgin resin and slate. This product meets building regulations for fire, and has British Board of Agrément approval, according to the researchers. Penetration of the UK market by replica slates is said to be small, though interest in slates containing recycled materials appears to be growing.
Comments
Ted Pederson, Technical Director at the Airport Business Centre, commented:
“The support and advice that WRAP provides has been vital to the success and progress of our used tyres research and development trial. This trial has enabled us to advance the use of ultra fine vulcanised crumb rubber that is derived from post consumer truck tyres, into a new composite roofing slate.
“There is already a wide range of construction applications using tyre-derived material and this trial will open up a new market within construction. The research and development stage has enabled us to create a new formula for an innovative product, which we hope will create an additional market for recycled rubber from tyres. In the meantime, we are continuing to monitor the trial and develop the commercialisation of the product with support from WRAP.”
Steve Waite, Project Manager for Tyres at WRAP, said:
“The material that can be broken down from used tyre rubber offers unique properties. These trials have demonstrated that ultra fine recycled rubber material is suitable for a variety of end uses. One of the main drivers for the WRAP Tyres Programme is to develop new markets for processed tyres and this rubber/plastic composite roof tile is an excellent example of newly created market opportunity.”
Further information
A full report on the findings of the research trial is available on the WRAP website. The WRAP construction site at www.wrap.org.uk/construction is also well worth a visit.