The Importance of Scrap Shredding

How the Shredder Changed the Face of Recycling and Roadside America

auto-graveyard-21.png
Roadside junkyards were a common scene. Mondo Cane (1962)

The scrap recycling sector is critically important to the manufacturing supply chain, providing 130 million net tons of feed stock annually for steel mills, foundries and refiners worldwide. About 70 percent of ferrous feed stock for U.S. steel producers comes from recycled material. For the scrap industry, one of the key tools in allowing it to be successful in recovering this material is the industrial shredder, an innovation that the scrap industry says ranks in importance alongside such other transforming technologies as the printing press, internal combustion engine and the personal computer.

So how did the shredder come to quite literally transform the world of scrap? Prior to the widespread use of the shredder, scrap metal recycling, including auto recycling, was painfully slow and inefficient. Old vehicles had to be dismantled with a cutting torch. Taking apart a single auto could take an entire day.

The growth of the automobile industry resulted in a gradual accumulation of old wrecks. From the early 1900s  onward, there was little interest in end of life automobiles. They were parked inbarns or pastures or simply abandoned on the side of the road. During World War 2, scrap metal drives did include old car recycling, but after the War, recycling again was was still very selective.

By the early 1960s, the production of new autos was widely outstripping the elimination of old vehicles, and increasingly, automotive wrecks were being looked at as an eyesore. The image for this article is a California roadside scene from the 1963 movie, Mondo Cane.

The auto wreck problem was addressed by the Highway Beautification Act of 1965, which was championed by First Lady Lady Bird Johnson. The Act called for the screening of roadside auto scrap yards, improved landscaping, and the removal of billboards.  

By the late 1960s, however, the industrial shredder was beginning to be become more popular, and the scrap automobile problem would continue to shrink in importance as time progressed.

Finally, a technology emerged that could help recycling keep pace with the pace of new car production.

Today, the shredder is looked at as essential to conserving natural resources as well as energy. Not only is scrap metal recovered, but the energy requirements to create steel from recycled metal are much lower than from virgin material. Case in point, the energy saving of recovering the metal versus virgin metal is equal to 502 gallons of gasoline, reducing greenhouse gases by 8811 lbs. 

With the capacity of handling 300-400 tons of scrap metal per hour, it is a powerful solution that can quickly process scrap and ready it for steel manufacturing and foundry industries.In addition, another key benefit of the scrap shredder, or scrap shredding system, is in the ability to liberate and separate different materials found in the objects that are processed. 

In automobiles, for example, there may several types of steel, in addition to non-ferrous metals and non-metallic material, which must be separated. Likewise, in electronics recycling, shredding is extremely important in liberating and separating valuable metals, where extremely sophisticated technologies such as magnets, eddy current and optical sensors are used to separate the various types of materials that have been separated during the shredding process.

Not to be overlooked, another benefit of shredding has to do with the importance of reducing the space requirements for material, meaning that more material can fit on a truckload, providing overall benefits in transportation.

So there we have it, the amazing shredder, the powerful workhorse that allowed the industrial world to close the loop on material recovery in a way that it previously could not.

Interested in seeing more about the importance of shredding? Check out this video from ISRI