New Ways to Process Hides into Leather

By Doris Stanley
November 27, 1998

New, environmentally friendly ways to turn cattle hides into leather while ensuring better quality products have been developed by Agricultural Research Service scientists.

Cattle hides are the most valuable co-product from the meat packing industry. The U.S. produces about 35 million hides each year. Exported hides bring more than $1 billion in foreign trade; those tanned in the U.S. are worth about $4 billion in finished leather.

For ages, processors have used salt to preserve hides because it draws out water. But each salt-cured hide produces a gallon of salt waste water, posing a disposal problem. Adding salt water to soil lowers its fertility.

At ARS’ Eastern Regional Research Center in Wyndmoor, Pa., biochemist David G. Bailey identified three solutions to the salt problem: potassium chloride, electron beam irradiation and gamma irradiation. Each is an effective, viable alternative to curing hides with salt. Industry doesn’t use these methods, but Bailey’s research is available if salt becomes a less acceptable preservative.

Using potassium chloride, or potash, to tan hides would benefit the environment because it is a plant nutrient. Potash is a little more expensive than salt, however, and would add about $2 to the cost of curing each hide.

Both electron beam irradiation and gamma irradiation protect hides from bacteria. In electron beam irradiation, cathode ray tubes similar to those in a TV set zap hides with energy beams of 3 to 10 million volts. Gamma rays are produced by a cobalt source at the bottom of a deep pool of water. Both methods are used worldwide on many products such as bandages and other soft medical supplies.

ARS, USDA’s chief research agency, features a story on hide processing in the NovemberAgricultural Research magazine. The story is on the World Wide Web at:

/is/AR/archive/nov98/tan1198.htm

Scientific contact: David G. Bailey, Hides, Lipids, and Wool Research Unit, ARS Eastern Regional Research Center, Wyndmoor, Pa., phone (215) 233-6486, fax (215) 233-6795, dbailey@arserrc.gov.