Sap from weeds the new black
Guayule shrub and dandelions produce rubber for tyres
TWO tyre makers from opposite ends of the world announced they are joining the quest to make tyres from sap that does not come from a rubber tree.
The idea is not new, but dates back to shortages in WW2, when Joseph Stalin had fields planted with the foot-high Russian dandelions (Taraxacum koksag-hyz, or simply “TKS”). This big dandelion grows like the weed it is in any cold to moderate climate, and can be pressed into a sticky sap, with insulin and biomass as by-products, every few weeks.
Adolf Hitler also grew TKS with forced labour. After World War 2, China and Russia continued to make tyres from TKS up to 1953. China has since moved on to the elm-like gutta-percha tree (Eucommia ulmoides), which produces a glutinous eu-gum from its trees, bark and stems.
In the U.S., the focus has been on tapping the sap from the guayule shrub,
(Parthenium argentatum) which grows in the deserts of the south-western United States. Last week, Cooper Tire demonstrated the prototype tyres it had made from guayule sap.
A large team is involved, with PanAridus growing the plants and manufacturing rubber from the sap, and the Cornell and Clemson Universities aiding and abetting in refining the systems.
Cooper Tire said it expects to make complete tyres from guayule-sourced rubber by 2017.
In Europe and Japan Focusing on the ubiquitous dandelions instead of guayule shrubs, Japanese tyre maker Sumitomo Rubber Industries (SRI) also announced last week it has entered into a joint research project with U.S. biotech company Kultevat to investigate using Russian dandelions as an alternative source of natural rubber.
Kultevat is a U.S.-based biotech company with extensive experience in farming sustainable and environmentally-friendly sources of rubber.
SRI is the world’s seventh largest tyre manufacturer, and aims to reduce its reliance on expensive and unsustainable fossil resources such as oil and coal, which account for approximately 60% of a conventional tyre.
SRI launched the ENSAVE 100 tyre in November 2013, touted as the world’s first tyre made without the use of fossil fuels.
Farmers ‘planting tyres’ Both Cooper Tire and SRI are following in the tracks pioneered by an European consortium involving 10 partners in seven countries from France to Kazakhstan and the U.S.
In all of them, there will soon be a market to plant weeds that will produce sap that can be turned into tyres.
The EU-Pearls (for the Production and Exploitation of Alternative Rubber and Latex Sources) is the consortium the helps farmers grow either guayule or TKS, depending on the climate.
Holland has long been ready to German TKS into rubber. In July 2012 Indian-Dutch company Apollo Vredestein showed its prototype tyres made from dandelions, and last year Continental also said they are ready to produce Tara gum tyres from the Russian dandelion, working with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME in Germany.
The U.S. grows guayule in the south and may grow TKS in the north, next to Canada, which is already growing the Russian dandelion.
Giant China is growing TKS in the north, Eucommia and guayule in central China and conventional rubber trees in its humid south.
The guayule shrub thrives in desert conditions and make a latex-like sap ideal for turning into rubber.
Europe’s small dandelion is not quite the foot-high weed from Russian, but its sticky sap shows why tyre makers are excited about the weed.