Guayule-based rubber firm granted international patent protection

By Bryan Sims | January 12, 2012

Chandler, Ariz.-based Yulex Corp. has been granted additional patent protection from patent offices in the U.S., Europe, Mexico and South Africa that cover commercial methods for latex and resin extraction derived from the guayule (pronounced “why-you-lee”) plant, a desert shrub, that’s grown in commercial farms throughout southern Arizona. Yulex has patent protection throughout Europe, particularly in those regions with climates suitable for growing guayule, including Greece, Cyprus, Spain, France, Italy and Portugal.

According to Jeff Martin, CEO of Yulex, the company’s entire business and patents are based on methods for cultivating, harvesting, defoliating and decorticating the guayule plant, as well as utilizing chemical and mechanical extraction techniques for the production of biobased elastomer products such as premium latex and resin (or bioadhesives) that can be used in an array of consumer and healthcare products.

Guayule (Partheneum argentatum) is a commercial crop and the only rubber-producing species other than the Brazilian rubber tree (Hevea brasiliensis) that has been used for latex production on a commercial scale.

“[The additional granted patents] give us the freedom to operate in all those areas surrounding that technology, not just in the U.S.,” Martin said. “We’re now going through the international phase with the patents.”

Martin told Biorefining Magazine that he first discovered the inherent benefits of guayule more than a decade ago when he learned about how the USDA was trying to extract a latex resin from the plant at lab-scale. Martin eventually acquired a license from the USDA for a patent that specifically described how to extract a nonallergenic rubber material from the plant. He subsequently founded Yulex (derived from the suffix of both words “gua-yule” and “lat-ex”) to apply and scale-up the production method, and the company has flourished since.

“Initially, we had started out focusing on medical devices,” Martin said, “As our business grew and we were able to get the cost of goods down associated with extracting the rubber, we saw applications in consumer and industrial products.”

According to Martin, Yulex’s guayule-based latex is offers an attractive alternative to other natural-based latex (or tropical rubber) materials currently in the North American market, which is imported to the U.S. exclusively from Southeast Asia. Currently, Yulex is the lone domestic natural rubber manufacturing firm in North America.

“The initial focus was on extracting a natural rubber from guayule that was nonallergenic because of all the problems associated with latex allergy in the U.S. and Western Europe,” Martin said. “There is a large percentage of the general population and even a larger percentage of healthcare workers who become sensitized to latex.”

In November, Yulex and Ansell Ltd, a global manufacturer of medical and safety protection products, executed an agreement for the global development, manufacturing and distribution rights for medical gloves, personal protective equipment gloves and condoms made from guayule latex.

Although Yulex is primarily focused on manufacturing its guayule-based natural rubber emulsions for the medical and consumer product markets, Martin said the company is also optimizing value-added applications for the lignocellulosic biomass that’s left over from extracting rubber or latex from the guayule plant.

“We have anywhere from 15 to 18 metric tons per acre per year of a very high-energy biomass, which is about 9,000 Btu per pound, that we have in the past sold to local biomass-fired power plants,” Martin said.

As for other applications of the residual cellulosic biomass, Martin said Yulex has demonstrated the production of ethanol and bio-oil via fast pyrolysis, and the company is delving into potentially upgrading the liquid biofuels to more useful advanced fuels such as biojet.  

“Short-term, we’re about biomaterials,” Martin said, “Long-term, we’ve got a beautiful local solution to advanced biofuels as our business grows because we’ve essentially paid for the entire cost of this feedstock in the cost of producing rubber from guayule. The limiting factor for us is really the growth of our rubber business. Right now, the amount of material that we’re producing enables us to sell rubber materials to a number of niche markets.”

Yulex controls every aspect of upstream logistics from breeding programs to agronomic development of the guayule crop, Martin said. The company has a partnership with in-state partner Arizona Grain to contract and finance the crop with Arizona Grain’s growers, which, in turn, deliver the crop to Yulex’s manufacturing facility in Chandler.

The company recently completed an expansion project to its guayule-based rubber manufacturing facility in Chandler, according to Martin, which is expected to come online later this month. The plant will have an annual production rate of 500 metric tons of finished biopolymer. The facility was designed to allow for rapid expansion as demand grows and is capable of adding additional equipment to increase capacity to more than 2,500 metric tons per year while retaining the same overall environmental footprint.