Finally, the development on the guayule shrub as a rubber alternative has come full circle, with tyre giants starting to roll out tyres made from the much-awaited plant rubber, to reduce the dependence on natural rubber from Asian sources.
US-based Cooper Tire has already completed building tyres using guayule rubber and is currently testing the tyres through rigorous wheel, road, and track tests.
The firm is working with consortium partners PanAridus, Arizona State University, Cornell University, and the Agricultural Research Service of the US Department of Agriculture (USDA-ARS). The partners received a grant of US$6.9 million from Biomass Research and Development Initiative (BRDI) in 2012 to conduct research for producing guayule as an alternative for synthetic and natural rubbers used in tyre making. The grant period ends in the second quarter of 2017.
Meanwhile, Bridgestone Americas, a subsidiary of the Japan-based Bridgestone, had earlier started operations of its Biorubber Process Research Centre, located in Mesa, Arizona. Officially opened in September this year, the 4-ha research centre will be the base for more than 30 researchers and technicians. It will be supplied with guayule grown on Bridgestone’s 114-ha Agro Operations Research Farm located in a nearby site in Eloy.
Guayule, which contains natural rubber under its bark, will be ground and rubber will be extracted using solvents. It will then be formed into 75-lb bales, which will then be sent to Bridgestone’s US technical centre in Akron and its Japanese technical centre in Tokyo. This development is part of the company’s goal of producing tyres with sustainable materials by 2020.
The process also will create waste-plant material that can be used in particleboard, to burn for electricity or in other potential markets. It also makes a plant resin, said Bridgestone.
Since guayule rubber processing is comparatively costly, Bridgestone is continuing to devise ways on how to make it more economical.
In a related development, PanAridus, an Arizona-based company that commercialises guayule, recently received its ninth Plant Variety Patent from the USDA, the same time it shipped its first bale of tyre-grade guayule rubber,
PanAridus, the chief guayule rubber supplier in the USDA/DOE-funded BRDI programme, said that orders are coming in. The firm joined the consortium in 2013 in the initiative to promote development and analysis of feed stocks, biofuels and bio-based products. It says that it is committed to undertaking continuous agronomic research into guayule, which has come a long way from being discovered two decades ago by a research team from the University of Arizona, as merely a desert shrub, to becoming a key alternative to natural rubber.
At the International Tire Exhibition & Conference (ITEC) show held in September in Akron, Michael Fraley, President/CEO of PanAridus said that the task at PanAridus to augment the supply of natural rubber will be realised with the breeding and development of some 300 types of guayule.
Guayule can be used for its biomass, energy and resins as much as for its rubber, Farley said. The guayule types that PanAridus has bioengineered mostly have shorter growing period than conventional guayule. The company has filed a patent for direct seeding.
Guayule will be cultivated not only in the southwest US and in northern Mexico, where the shrub is indigenous, but also in Europe.
The EU-based Production and Exploitation of Alternative Rubber and Latex Sources (EU-PEARLS) Consortium has linked stakeholders in the EU in the development of guayule, as well as the Russian dandelion (TKS), another biorubber source currently at the fore of studies, to establish complete new value creation chains for natural rubber and latex from these plants. As a result of the research, experts say that guayule can now be successfully grown on marginal lands in semi-arid regions of European Mediterranean countries.
Under the EU-PEARLS, CIRAD, France’s Agricultural Research for Development; and Wageningen University (UR), a university research centre in the Netherlands, will be able to acquire more knowledge on the genomics and agronomy of guayule, especially on the extraction process of rubber and resins, rubber quantity and quality measurement. The partners were able to produce rubber gloves and tyre prototypes.