Green Rubber: Rallying points for sustainable rubber

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Industry stakeholders are taking up the challenge of securing rubber supply without letting up on efforts to ensure food security, energy efficiency, human rights, and environmental integrity; while new technologies in the green rubber arena are being introduced, says Angelica Buan in this article.

Global key players focusing on closing the demand-supply gap for natural rubber, on account of rising global consumption, especially in the automotive and transportation sectors, are ramping up natural rubber production.

By 2020, natural rubber production is to exceed 19 million tonnes, the International Rubber Study Group (IRSG) notes.

As lucrative as it may sound, increasing natural rubber production has a bearing on the environment and is associated with food insecurity, water consumption, and deforestation – since rubber trees grow in the same area where the rainforest grows; not to mention sporadic land grabbing incidences that displace farmers and rubber growers. Hence, industry allies are forming initiatives with government and non-government agencies to promote and adopt sustainable rubber in the supply chain.

Tyre/automotive giants bid for sustainability in supply chain

US tyre maker Goodyear, which reported tyre unit volumes totalling 39 million in the first quarter of 2018, has penned a new natural rubber procurement policy, stating the company’s commitment to responsible sourcing. The policy covers the entire supply chain, including smallholders, industrial plantations, intermediate dealers/consolidators, processors, trading companies, and Goodyear itself.

The Akron-based company, which manufactures its products in 48 facilities in 22 countries worldwide, believes that the implementation of this policy will help address critical issues including deforestation, land grabbing, and human rights throughout the supply chain. The new policy, in a nutshell, helps to protect the environment by promoting environmentally and socially responsible land use.


The policy outlines Goodyear’s prescriptions to develop a long-term sustainable supply chain, including responsible land acquisition and use, natural rubber processing, traceability of natural rubber through the entire supply chain and use of best-known cultivation practices for existing planted and replanted NR trees. It also extends to community development programmes, and as already mentioned, human rights protection and policy compliance to ensure transparency in carrying out its policies.

Goodyear is a member of the Tyre Industry Project (TIP), a CEO-led initiative made up of the world’s 11 major tyre companies, including Bridgestone, Continental, Cooper Tire & Rubber Company, Hankook Tire, Kumho Tire, Compagnie Générale des Établissements, Michelin, Pirelli, Sumitomo Rubber Industries, Toyo Tire & Rubber, and Yokohama Rubber; representing approximately 65% of the world’s tyre manufacturing capacity.


TIP initiates and supports research, including inventing equipment and methodologies, to improve the sustainability efforts of the tyre industry. Since its creation, TIP has established distinct working groups that address tyre industry issues, under the Geneva-headquartered organisation, World Business Council for Sustainable Development.

Tokyo-headquartered tyre maker Bridgestone also heralds its own Global Sustainable Procurement Policy to help identify and evaluate qualified suppliers, promote best practices, and serve as a communication and improvement tool for the industry.

The new policy highlights Bridgestone’s goal of using 100% sustainable materials in its products by 2050. It also underscores Bridgestone’s four major areas of focus, including sustainable procurement practices that cover environmentally responsible procurement, respect for human rights, water use, land use and conservation, health, safety, disaster prevention and resilience.


Bridgestone is the world’s largest tyre and rubber firm, garnering net sales of over US$32 million in 2017, and with products sold in over 150 nations and territories worldwide.

Another member of TIP, German automotive technology company Continental, has partnered with German development agency Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) to push for sustainability in the natural rubber supply chain; and improve the livelihoods of rubber tree farmers in Indonesia, the world’s second largest rubber producer. The partnership, announced early this year, aims to develop a criteria catalogue for sustainable production of natural rubber; to train farmers in sustainable production in accordance with these criteria; and to track the rubber from smallholders to production at Continental.

Improved rubber quality, higher yields and supply chain optimisation will generate higher incomes for rubber tree cultivators. The tie-up is part of the programme initiated by the German Federal Ministry for Economic Cooperation and Development (BMZ). BMZ promotes deforestation-free supply chains; and the initiative has been extended to the production of commodities, including rubber, palm oil and cacao, in Indonesia and the Ivory Coast.

The partnership will implement a traceability system and increase the traceable production of rubber in West Kalimantan over the next three years. In total, 400 farmers will be trained to grow high-quality rubber in accordance with clearly defined sustainability criteria. An electronic system will be developed to ensure full traceability of the raw material along the entire supply chain.

Continental, for its part, has prepared a specific natural rubber sustainability policy, highlighting its commitment to securing a healthy and compliant supply chain and a zero tolerance attitude toward deforestation, land grabbing and other practices that harm local populations and the entire eco-system.

Like its automotive maker peers, Detroit-sited General Motors (GM) has sustainability in its ethos. In 2016, GM made headlines by its use of recycled plastic bottles collected from its facilities to make noise-reducing fabric insulation that covers the Chevrolet Equinox engine. GM’s latest sustainability report calls attention to its mobility and zeroemission vehicles strategies, specifically outlining how it has progressed in lightweighting vehicles, utilising renewable energy, building landfill-free facilities, and other such moves to promote sustainability.


In 2017, it bared its agenda of sourcing sustainable natural rubber in its tyres. It said that doing so would sow benefits for the community, the business and the environment. Sustainable rubber sourcing, it said, translates to preserving and restoring primary forests and protecting wildlife; improving yield and quality for natural rubber farmers; and ensuring long-term availability of rubber.

Developing biobased rubber for tyres and car parts

Japanese tyre maker, Yokohama Rubber Corporation (YRC) has collaborated with synthetic rubber manufacturer Zeon Corporation, and Japanese national R&D agency, Riken, in developing a new technology for the efficient and stable production of isoprene from biomass.

Isoprene is the raw material for polyisoprene rubber, which is mainly used for automobile tyres. Currently, industrial isoprene is produced as a by-product of the naphtha pyrolysis. The team said that this new technology has the potential of not only reducing dependence on petroleum, but also contributing to reducing carbon dioxide in the environment.


Discovering in 2015 an isoprene-synthesising process using computer-based in-silico metabolic design technology, the group started developing the world’s first technology to create sugar-based isoprene that serves as the starting material. The group has also succeeded in synthesising polyisoprene rubber through the polymerisation of in-vivo generated isoprene. This technology can also be applied to butadiene-based synthetic rubber and other diene rubbers.

YRC is also looking into natural rubber research it started in 2013 with Thailand’s Mahidol University and Prince of Songkla University. The research with the latter university analysed the differences in latex related to different seasons and regions, different varieties and different processing methods; as well as evaluated the presence or absence of changes in the physical and chemical properties of rubber over long periods of time.

On the other hand, the study with Mahidol University involved analysing more than 800 proteins contained in latex, and identifying the proteins involved in NR biosynthesis. The company plans to use the results of this research to promote the maintenance and development of natural rubber plantations.


Meanwhile, synthetic rubber manufacturer Arlanxeo’s Keltan Eco is dubbed as the world’s first EPDM rubber manufactured using biobased ethylene extracted from sugarcane. The Netherlandsheadquartered firm introduced new thermoplastic vulcanisates (TPVs) recently that combine Keltan Eco EPDM with green fillers, plasticisers and thermoplastics, resulting in EPDM products with up to 90% sustainable ingredients. The development of thermoset rubber compounds and TPVs based on Keltan Eco EPDM aims to maximise sustainable content without compromising technical performance, said the company.

Niels van der Aar, Business Development Manager EPDM/NBR at Arlanxeo said biobased TPVs can make a significant contribution to the circular economy, scoring well in a cradle-to-cradle approach and helping to lower the carbon footprint.

The new biobased EPDM grades have been commercially tested and used in window profiles for buses and buildings, automotive extrusion profiles, TPV over-mouldings for automotive interiors, and other applications.

Increased recycled materials in tyres

Michelin North America is closer to achieving predominantly sustainable materials-based tyres. The plan, announced in May during the Movin’On 2018 sustainable mobility summit held in Montreal, Canada, is to ensure all of its tyres will be manufactured using 80% sustainable materials within 30 years to 2048, and that 100% of all tyres will be recycled.

Michelin is progressing into its 2048 plans with its continued partnership with Georgia-based Lehigh Technologies, enabling it to manufacture its micronised rubber powder (MRP) to reuse end-of-life tyre materials.

Lehigh Technologies, which was acquired by Michelin in 2017 and has since then been a key partner in the former’s closed-loop approach, converts rubber materials into a technology powder that can be incorporated in new retread compounds offering higher levels of performance. MRP replaces oil and rubber-based feedstock in a wide range of industrial and consumer applications, including highperformance tyres, plastics, consumer goods, coatings, sealants, construction materials and asphalt.


In July, Lehigh Technologies started production of MRP at its new plant in Navarra, Spain, which is its first outside of the US. Built in partnership with Spanish environmental group, Hera Holding, the plant incorporates Lehigh’s proprietary cryogenic turbo mill technology and has the capacity to produce 10,000 tonnes/year of MRP. The plant will produce Lehigh’s PolyDyne and MicroDyne range of MRPs.

Thus, it can be seen that tyre and automotive giants are taking a serious purview of the rubber industry, from the supply value chain to end-use products, to ensure that the industry maintains its sustainability.