Natural rubber


Natural rubber (NR) is an inseparable part of most rubber-based products, such as tyres, and cannot be substituted by synthetic rubbers. Currently, the only viable source for NR is the rubber tree (Hevea brasiliensis) which grows mainly in Southeast Asia. The world market for NR increased from 4.4 Mton in 1985 to 11.2 Mton in 2012. The rubber demand is expected to increase by another 5-6 Mton in the coming 10 year, primarily because of an increasing demand for vehicles and tyres (car, motorcycles and bicycles) in China and India.

Based on IRSG forecasts (www.rubberstudy.com), the NR consumption is expected to reach 16.5 Mton by the year 2020, with the tyre industry accounting for 12.6 Mton and general rubber goods industry for 3.9 Mton. China will retain the major NR consumer in 2020 accounting for over 7 Mton, followed by India, Europe, the US and Japan. The global NR production is forecasted by IRSG at 15.2 Mton, indicating a deficit of 1.3 Mton.

The combined supply and demand forecasts suggests that the NR market will move into a deficit of 0.4 MT by 2025. In the past 5 years already, the market suffered from huge price changes (>2.5x change within a 2-years window). In view of the anticipated short supply after 2023, the high price volatility may even worsen in the future.

Overall, several studies present an encouraging scenario for NR, with increasing rubber-demand until 2020 and possibly beyond. However, also concerns have been raised, especially by European NR users, as to whether the production of NR can keep up with the projected demand and other future needs. Such worries are related to:

  • Climate change. Studies reported that change in rainfall pattern in e.g. Southern Thailand (>30% of global NR supply), resulting in heavy rains during tapping season, significantly reduced NR/latex yield.
  • Limited possibilities for expansion of cultivation area in wet/warm climate regions close to the equator, which is typically required for the rubber tree, partly because of competition with more profitable crops (e.g oil palm).
  • Fungal diseases. There is the permanent danger of unintentional introduction South American Leaf Blight Disease (SALB) into Southeast Asia, the fungal disease which once makes rubber plantations in South America impossible, that may devastate the non-resistant clones used in Asian rubber plantations.
  • Compliance with EU regulations. When a rubber tree is planted, it takes 6-7 years before latex can be tapped. TKS is an annual crop and rubber using manufacturers can respond more quickly to new market demands by increasing temporarily the acres of cultivated land. Since breeding of TKS can result in various cultivars with different quality of natural rubber (molecular weight, resilience, viscosity), "specialty cultivars" can be grown that produce a natural rubber with specific properties leading to rubber compounds that comply better with new regulations (2012, new thresholds regulations for energy efficiency, wet grip and rolling noise).

All these factors illustrates the fact that the development of an European source of NR is essential for the EU NR industry. In the USA emergency rubber program (between 1930 and 1950), TKS rubber was tested as car tyres. A road test was discontinued after 21,848 miles, although none of the tires had failed. It was concluded that koksaghyz rubber performs as satisfactory as Hevea rubber in the carcasses of heavy duty tyres. Its tread wear is slightly less than that of Hevea rubber. Whaley and Bowen (1947) stated that "koksaghyz rubber was much superior to that from guayule". In the EU-PEARLS program, the koksaghyz rubber produced in the field trials was tested for application in car tyres. Apollo Vredestein has processed raw rubber samples from Russian dandelion in tyre formulations and has produced the first sets of car tyres for testing purposes. The alternative rubber samples were part of the tread and with respect to properties like wet grip the tyres behaved equally, if not superior to the conventionally produced winter tyres (http://prod-euronews.euronews.net/2012/11/07/a-tyre-revolution-rolls-around/).

The tyres produced by Apollo Vredestein in EU-PEARLS are the first tyres produced from TKS-rubber since WWII. Since WWII, all rubber containing products have improved their performance significantly. For example, car tyres are now specifically designed to perform under severe circumstances (heat, cold, wet, snow, etc.) with low costs (during manufacturing, but also during use (rolling resistance)). The current tyres contain Hevea NR or synthetic rubber and apart from a single high speed car tyre test, no test program with TKS rubber has been performed.