AKRON-The American Scientific Testing Materials Committee on Rubber is reviewing a proposal by a subcommittee on recycled rubber that, if approved, will change the way crumb rubber is specified. ``There are very few accepted standards at this point,'' according to Floyd Karp of the Clean Washington Center in Seattle. ``Generally, they don't have a lot of meat, which leaves them open to a lot of interpretation.''
``Right now it is the biggest obstacle impeding the marketplace,'' said Michael Blumenthal, executive director of the Scrap Tire Management Council.
``(Specifications) are not accepted or in practice,'' added Tim Leighty, vice president of operations at Recycling Technologies Inc. of Hanover, Pa. ``People are doing their own thing.''
With that kind of lax observance of the present ASTM specifications, which were set in 1994, the industry is suffering from a serious case of distrust, according to sources.
``Buyers are sometimes hesitant, because they can't get the same quality material on a consistent basis,'' Mr. Blumenthal said. ``There needs to be one established definition and standard protocol for ground rubber.''
``Everybody we talk to has that common complaint,'' added Mr. Leighty. ``Some people don't perform tests because they're afraid to find out exactly what their material qualifies as.''
That's why Krishna C. Baran-wal, the Akron Rubber Develop-ment Laboratory Inc. executive who serves as chairman of the subcommittee on recycled rubber, believes the proposal in front of the ASTM will help eradicate that problem.
``Our job is to modify the current specifications to be more useful to the recycled rubber industry,'' Mr. Baranwal said, ``and to put more teeth into the specifications.''
The 11-member subcommittee comprises both buyers and sellers. ``We wanted to make a realistic specification that both producers and users can live with,'' Mr. Baranwal said. ``The only way to do that is to get both sides involved.''
The proposed standards contain 50 percent more specifications than the current guidelines, according to Mr. Baranwal. The major difference in the proposal involves establishing specifications for 10-, 20-, 30-, 40-, 60-, 80- and 100-mesh crumb rubber.
The proposal also adds metal and fiber content specifications: Metal content should be no more than 0.1 percent, while the fiber content should be no more than 0.5 percent.
``This all controls the type of material a buyer is getting,'' Mr. Baranwal said. ``It will definitely improve the quality of the product.''
That will make a difference, according to Recycling Technologies' Mr. Leighty. ``Once everyone is forced to use standardized tests, it will help the industry,'' he said. ``Anything that's going to hold a crumb producer's feet to the fire to satisfy what the customer wants will be helpful to the industry.''
Establishing a set of standards is becoming increasingly important in an industry that, by all accounts, is still in its infancy.
Because applications for crumb rubber are becoming more complex and the product needed is becoming more precise and smaller, a set of standards adopted by the entire industry will put many minds at ease.
``The finer the crumb, the easier it is to use as filler,'' according to Bill Barbin, Goodyear's director of compound technology projects. ``But the finer it is, the more expensive it is, and therefore you need a reliable source.''
``Finer means more expensive and more expensive typically means better,'' said Ken Wallace of Michelin North America. ``What your source is for raw material is very important. The quality of that (raw material) will directly affect how we handle (it) in the plant. It's important to have standards that all suppliers can adhere to.''
Another major difference is that the proposed specifications will contain the word ``recycled.''
``The current specs have no reference to recycling whatsoever. Adding the word `recycled' adds a positive environmental impact statement,'' Mr. Baranwal said.