The hammer-mill shredder is the machine that turns cars, appliances and light iron into shredded steel, Zorba and fluff. It is the largest investment a scrap yard makes and the one that defines what grades it can sell.
The hammer-mill shredder is the machine that turns cars, appliances and light iron into shredded steel, Zorba and fluff. It is the largest investment a scrap yard makes and the one that defines what grades it can sell.
A shredder is a heavy rotor carrying swinging hammers inside an armoured housing, driven by a motor of anywhere from 1,000 to 10,000 horsepower. Flattened cars, white goods and loose light iron are fed in by a compression feeder; the hammers tear the material against anvils and grates until the pieces are small enough to fall through. Downstream, drum magnets lift the steel out, air systems blow off the light fluff (foam, fabric, plastic, dust), and eddy-current separators recover the non-ferrous metals as Zorba.
Shredders are rated by rotor size and motor power — a “98/104” class machine, for instance, refers to the rotor diameter and width in inches. Mega-shredders in the US and Europe process several hundred tonnes an hour; smaller units of 500 to 1,500 horsepower serve regional yards in India, Turkey, the Gulf and South-East Asia.
A shredder plant makes three products: shredded steel (the premium ferrous grade), Zorba (the mixed non-ferrous metals, sorted further into Twitch and heavies), and automotive shredder residue, the fluff that must be landfilled, burnt for energy or further processed to recover the last metals and plastics. The economics of a shredder depend on the second and third as much as the first.
The large European and American makers build the big machines and the downstream separation plants. Indian makers build smaller units for the domestic market, and Chinese makers export mid-sized shredders across Asia, the Middle East and Africa. Second-hand shredders are also traded internationally, with the rotor and motor condition deciding the price.
Long-established makers of this class of machine. Names first; the buttons go deeper.
| Maker | Where | Machines | |
|---|---|---|---|
| Danieli Centro Recycling (Danieli & C. S.p.A.) | Buttrio, Italy | Shredders, shears, balers | |
| Lindemann GmbH (Metso) | Düsseldorf, Germany | Shears, shredders, balers | |
| Weima Maschinenbau GmbH | Ilsfeld, Germany | Shredders, briquetting | |
| Bano Recycling S.r.l. | Campodarsego, Italy | Rotary shredders for non-ferrous | |
| Jiangsu Huahong Technology Stock Co., Ltd. | Jiangyin, China | Shears, balers, shredders, briquetting | |
| Advance Hydrau Tech Pvt. Ltd. | New Delhi, India | Balers, alligator shears, shredders |