Industrial shredders vary in many ways, according to the function they perform. The internal mechanical processes may include cutting, grinding, hammering and compression. Many shredders also incorporate shaking/sorting mechanisms. Internal machinery may travel in rotary, lateral or vertical directions. Speeds of the internal processes also vary widely, to suit the materials the machines will be handling. Shredders can be partially categorized by the type of process or processes they employ.
Shear Shredders employ rotary cutters or guillotine-style knives to cut materials rather than pulverizing, chipping or grinding. Shears can be found in many different configurations for different industries. Feed types, speeds and type and number of knives differ according to the applications.
'All Purpose' Shredders are the heart of major demolition operations and many municipal recycling programs. The machinery usually consists of large, very low speed, high-torque shafts or drums with carbide cams or studs, sometimes equipped with hydraulic rams to assist with the feed. Many of these shredders are capable of reducing entire refrigerators, cars, or other oversized equipment to small pieces in a single pass. They are most often combined with external systems that remove hazardous liquids, gases or solids, sort metals from other materials and otherwise prepare the shredded material for disposal and/or reuse.
The advantages of using mega-shredders in large-scale waste disposal systems, such as municipal landfill / recycling centers, are fairly obvious. Plastics, wood, rubber, asphalt and similar materials can be immediately reduced to a mere fraction of their original size and many can be sold or given directly back to the public for distribution as useful products. Bio-degradable products will decompose faster after shredding. Shredding also allows those materials that will end up buried forever in landfills to be compacted into a much smaller space with fewer voids, resulting in a more stable base for future development.