There are several types of shredders, from very simple paper shredders to high-tech disintegrators and hammer mills. Paper shredders can be subdivided based on the size of the final shredded pieces. Home and small business applications generally use the simpler types of shredders, while larger corporations and government entities use more sophisticated shredders to protect highly sensitive information. Industrial companies use hammer mills and pierce-and-tear shredders to dispose of various materials, including cardboard.
The strip-cut shredder uses a rotating blade to cut paper into long strips. This is the simplest, and least secure, means of destroying documents, as the strips can be reassembled by someone with enough time and patience for the task. Different strip shredders result in different strip widths, from 3/8 inch to 1/16 inch. From a security standpoint, the narrower the strip, the more effective the shredding.
Also called "confetti shredders," cross-cut paper shredders use specially designed blades to slice paper into small squares or diamond shapes. These pieces range from 3/8 inch wide to 1/32 inch wide, in varying lengths. The smaller size of the pieces increases the security level of the shred. Cross-cut shredders are widely available and are relatively inexpensive, making them one of the most popular choices for small businesses and personal use.
The most secure of paper shredders, micro-cut shredders reduce paper into minuscule particles. The most secure (and most costly) can reduce a single sheet of paper to more than 12,000 pieces. These types of shredders are typically used by research facilities and government agencies to provide the best possible security in disposing of top-secret documents.
Disintegrators are heavy-duty shredding machines that use multiple blades to shred paper until the particles are small enough to pass through a sizing screen. Two blades are mounted in a fixed position, while two to five more blades are affixed to a rotating drum in the center of the machine. Some disintegrator models can shred CDs, DVDs and other optical media, as well as tape and USB flash drives.
Hammer mills are similar to disintegrators. Rotating hammers pulverize the paper (or other material) and pass it through a sizing screen to achieve the highest level of destruction. The hammers may have knife blades, blunt edges or a combination of the two. Users can change the screen size to fit their particular needs. With the right screen in place, a hammer mill can reduce paper to dust.
Used primarily in industrial applications, pierce-and-tear shredders use multiple rotating blades that punch holes in the material being shredded, and then rip the material into tiny pieces. Most mobile shredding companies use a truck that incorporates pierce-and-tear technology and a large holding bin for the shredded material. Pierce-and-tear shredding is also widely used in industrial and manufacturing operations, to dispose of cardboard and specialty papers like newsprint.