New Green Source for Tires

Guayule plants are supplying a new natural rubber for vehicle tires.

Natural rubber is a primary raw material used to produce tires. About 90 percent of all natural rubber is harvested from the Hevea brasiliensis tree, native to tropical regions of Southeast Asia.

Guayule (Parthenium argentatum), a rubber producing desert shrub indigenous to Mexico and the Southwestern US.

Guayule (Parthenium argentatum), a rubber producing desert shrub indigenous to Mexico and the Southwestern US.

The natural rubber-containing components from the guayule plant (Parthenium argentatum), a desert shrub that grows in arid regions, may soon disrupt this monopoly.

All the major natural rubber components in a tire, including the tread, sidewall and bead filler, can be replaced with natural rubber derived from the guayule plant. 

New tires are now being developed that are made with guayule cultivated, grown and harvested by Bridgestone in their Arizona-based Biorubber Process Research Centre (BRPC).

Natural rubber contained in the guayule plants’ bark and roots can be extracted and processed into a commercial grade rubber.

Bridgestone reveals tires made entirely of natural rubber components from the company's guayule research operations. (Photo courtesy of Bridgestone Corporation.)

Bridgestone reveals tires made entirely of natural rubber components from the company’s guayule research operations. (Photo courtesy of Bridgestone Corporation.)

Extracting the rubber involves grinding the plant into a homogenous solution, which breaks open the plant’s cells to release the rubber particles. This solution is placed in a centrifuge to separate the lighter rubber particles, which can be culled off the top and processed.

The biomaterial derived from the guayule plant shares similar characteristics to the natural rubber harvested from the Hevea rubber tree.

Additionally, this isn’t the first time guayule-derived rubber has been used as a substitute for Hevea brasiliensis.

In commercial latex production for medical rubber gloves for instance, guayule is used to make hypoallergenic products for use by those with a latex allergy. 

Guayule does not contain the same sensitizing proteins as those found in Hevea and so guayule latex products will not cause allergic reactions in latex-allergic individuals.

However, this is the first time guayule rubber has been used in such a large scale application.

Guayule grows primarily in arid regions of the Southwestern US and Mexico, as opposed to the tropical regions where Hevea brasiliensis is found. Development of guayule cultivation and therefore commercial production aims to contribute to the diversification of natural rubber sources. 

As it’s cultivated in arid land, guayule cultivation will not displace or replace food crops, since it can grow where commercial food crops would likely fail.

Guayule under cultivation. (Photo courtesy of Bridgestone Corporation.)

Guayule under cultivation. (Photo courtesy of Bridgestone Corporation.)

Bridgestone’s research farm employs advanced breeding practices aimed to develop guayule cultivation techniques and they have established the in-house processes necessary to develop guayule rubber for use in tire applications, including research and development, experimental production and manufacturing.

Bridgestone believes the demand for vehicle tires will increase in conjunction with global population growth and greater levels of motorization in developing nations.  They hope their research will help achieve their environmental goal of 100 percent sustainable materials in their tires.

For more information on Bridgestone’s guayule rubber research and cultivation, check out their website.