The 6,000-square-foot pilot plant in Wooster makes gloves and a variety ofother latex and rubber products. This is nothing new in a town and regionhistoricallyknown for rubber manufacturing. What's different about the facility is thesource of its natural rubber: plants grown in the United States rather than theSoutheastAsian trees that currently provide all of the world's supply ofnatural rubber.
Establishedearlier this year, this unique pilot plant is operated byOhio State University's Ohio Agricultural Research and Development Center (OARDC). It's acrucial step in theuniversity's effort to develop and commercialize domestic naturalrubber sources that could one day replace a portion of the imports of thisstrategic yet largely overlooked rawmaterial.
While led byOARDC, the project -- funded by a $3 million Third Frontier grant from thestate of Ohio -- also involves the U.S. Department of Agriculture, theUniversity of Akronand Oregon State University. Industry partners include Bridgestone,Cooper Tire, Veyance Technologies and Ford Motor Co.
"Naturalrubber is probably the most underappreciated critical resource that we have,"said Katrina Cornish, project leader and OARDC endowed chair in bioemergentmaterials."There are over 40,000 things made with natural rubber, including 400medical devices. Life as we know it wouldn't be possible without naturalrubber."
Driving to thegrocery store wouldn't be possible. Neither would be flying around the world.Even with the most sophisticated advances in synthetic rubber technology,passengervehicle tires need about 50 percent natural rubber content toadequately resist the road's demands, said Hiroshi Mouri, president ofBridgestone Americas Center for Research &Technology in Akron.
And in thecase of aircraft tires, they are made entirely from natural rubber.
"It’s veryimportant to have an alternate source of natural rubber," said Mouri, who worksclosely with OARDC in the project. "We want to diversify the sources of naturalrubberto make sure our production is sustainable. The rubber tree has ahistory of extinction in the past in Brazil, and if that happens in SoutheastAsia, we won't have a source of naturalrubber. So it's important to have otheralternatives."
Thosealternatives includeTaraxacum kok-saghyz,or TKS -- a type of dandelion native to the former Soviet republicsof Kazakhstan and Uzbekistan. This plant can produce largeamounts ofrubber in its roots and can grow in Ohio and other temperate areas of NorthAmerica. OARDC researchers have been working for the past six years on turningthis weedinto a crop that can grow on a consistent, predictable basis and canyield as much rubber as possible.
The secondplant being researched at OARDC is guayule, a shrub native to the southwesternU.S. that produces rubber safe for latex allergy sufferers. Cornish is anational experton guayule, having served as senior vice president of researchand development for Yulex, a company founded to commercialize the technologyshe developed while working for 15years in the area of domestic rubber cropdevelopment with the U.S. Department of Agriculture. Cornish and other OhioState researchers are conducting trials in southern Ohio totest theadaptability of guayule to the region.
OARDC's pilotplant now allows researchers to produce rubber samples from these plants thatare large enough for industry testing. In the case of TKS, this is accomplishedthanksto rubber-extraction equipment based on a process initially devisedduring World War II (when the U.S. first studied TKS), and which has beenrefined and further developed byOARDC biosystems engineer Fred Michel.
The pilot plantcan produce compression-molded and dipped products, such as medical gloves;macro, micro and nano fillers, which are used in a variety of industrialproducts asreinforcement; and filled latex and rubber test samples. OARDCconducts latex and some rubber testing, while polymer science experts at theUniversity of Akron carry outadditional rubber testing to see if the samplesmeet industry standards.
So far, theresults are favorable.
"Our recentstudies continue to indicate that TKS has the potential to produce similar propertiesto Asia-produced rubber," said Mouri, whose team at Bridgestone has alsodeveloped prototype tires made from guayule rubber. "We work very closely withOhio State because we don't have expertise in plant breeding and agricultural research.Ourexpertise is in evaluating if the rubber is suitable for tire applications.So we make a good combination."
Makinga new crop
While guayulehas been the subject of significant research and commercialization in the past,TKS is just now in the process of crop development, said Matt Kleinhenz, wholeadsthe TKS breeding and agronomy program at OARDC.
This processstarted in 2006 with a small number of TKS seed collected in the wild. Roots ofthose plants contained 1.2 percent rubber on average. Growing in greenhouses,in hightunnels and in open fields, those seeds been crossed over the past fewyears, generating groups of plants that are continuously evaluated forcharacteristics such as growth rate, rootstructure and, of course, rubber yield.This year, Kleinhenz's research team produced close to 13 million TKS seedsfrom plants containing nearly 9 percent rubber on average.
These seedsare a unique collection that researchers hope will become the foundation forTKS as a crop.
So far, plantswith roots containing up to 20 percent rubber have been developed, Kleinhenz said.By comparison, the common dandelion,Taraxacumofficinale, produces little to nousable rubber. TKS has been planted andharvested in both spring and fall. Either way, the cold of winter appears to helpto increase rubber content, he explained. Also, the plantrequires few agriculturalinputs, increasing its potential as a cash crop.
"It’s rare to havethe opportunity to develop a new crop from scratch," Kleinhenz said. "It’s complexand requires a lot of work.
"But when we succeed,TKS will provide farmers in Ohio and beyond with another option to add to theircrop rotations and make money. It will also generate jobs and additionaleconomic activity from transportation, equipment manufacturing, processing andother activities in the supply chain."
TKS roots alsocontain inulin, a carbohydrate used as an additive in foods such as yogurt andwhich can also be converted to fuels such as ethanol and butanol.
More research stilllies ahead to breed a plant with the right combination of agronomiccharacteristics that would make a suitable crop for farmers to grow. Otherconsiderations, suchas seeding rate per acre, are being worked out as well. Researchersare also looking for the most effective way to control weeds in TKS stands,since cultivation is out of the questionbecause the plants lay too close tothe ground.
"TKS is notgoing to survive as a crop without effective weed control," said John Cardina,an OARDC weed expert. "This plant is not very aggressive. As a weed, it’sactually a bitof a wimp.
"It doesn'tgrow fast and doesn't cover much ground, which means weeds can take up a lot ofroom quickly, taking away light availability, nutrients and water from TKS.Chemicalcontrol is our best option, but there's the challenge that TKS isclosely related to things we now treat as weeds and that available herbicideskill."
Cardina hastested a variety of herbicides and found three post-emergent products that looklike good candidates. These are herbicides currently used in crops closelyrelated to TKS,such as lettuce and sunflowers. He said he hopes to have apackage of weed management options ready next year, after running additionalexperiments.
Theimportance of developing alternative sources of natural rubber becomes clearwhen considering thattherehas been a shortage in the supply of this critical resource every yearsince2004, said Bryan Kinnamon, Industry Liaison Office director for Ohio State'sCollege of Food, Agricultural, and Environmental Sciences -- which includesOARDC. Rapidlyincreasing demand from emerging economies such as China andIndia is behind the shortage.
This situationhas led to supply uncertainty and price volatility, which affect industriesdependent on natural rubber. And things are expected to get worse.
"By 2020, theglobal shortfall of natural rubber is projected to be more than the entireamount (1.2 million metric tons) the U.S. imports every year," Cornish said.
Moreinformation about the natural rubber project is available athttp://www.oardc.osu.edu/penra/.