how a paper shredder works

Shredders are ubiquitous in most offices today. Like the photocopier and the printer, paper shredders have become a necessity in modern office environments.

But have you ever wondered just how do paper shredders work? How are they able to cut through those sheets of paper into thin strips or fine particles?

Types of shredders

Answering the question we have posed will require us to consider the various types of shredders. There are three main types of shredders:

  • Strip cuts:  They cut the paper into thin strips. But with determination, someone can easily reassemble the document. These least secure of shredders have rotating knives which cut the paper into strips which are as long as the sheet of paper you are shredding. They also create a high volume of waste since the strips are not compressed.
  • Cross-cuts: These reduce the paper to tiny, chopped-up bits. They have two contra-rotating drums which cut the paper into rectangular, lozenge (diamond-shaped), or parallelogram shreds.
  • Micro-cuts:  These will turn the piece of paper into nothing but confetti. It’s impossible to retrieve the document afterward.

How Do Paper Shredders Work

How do paper shredders work

First, the machine snatches the paper from the feeder, and moves it through the shredder, culminating in the destruction of the sheet of paper. To accomplish this snatching/moving process, the shredder uses rollers of various materials or sizes.

The machine is designed to guide the paper through the machine, ensuring it keeps in line. This is important because if the paper does not keep in line, it will jam in the shredder.  Below are the rollers.

If the path through which the paper travels through is wide, you can feed more sheets at a time into the shredder. There will also be more rollers in the machine. The importance of the rollers is in keeping the paper moving smoothly through the shredder. They ensure the paper gets to the blades.

Next, the machines cut the paper. How the cutting happens depends on whether your shredder is a strip-cutting or cross-cutting device.

Strip-cutting Shredders

strip cut

The effectiveness of strip-cutting hinges on the action of several sharp, serrated, circular wheels. The wheels are set up in such a way that their serrations are not in line, wheel to wheel. The importance of the serrations is to exert a pulling action on the paper when the rollers deliver it.

Without the serrations, the unit wheels would spin endlessly without having any real hold on the paper. The serrations also help to move the paper through the shredder. The wheels are set within the shredder in such a way that at every step of the way, there will always be at least one serration grabbing hold of the paper, ensuring continuous movement.

But not all strip-cut shredders operate this way. Higher-duty strip-cutters have a different mechanism. Rather than serrated wheels to cut the paper, these shredders come with serrated blades which moved in an upward and downward motion of the frame to which the blades are attached.

If you adjust the angle of the blades or increase the horizontal movement of the frame, you will be able to increase the cutting power.

Cross-cut Shredders

cross cut

These devices have a more complex process. They have two sets of serrated blades which are set at angles that face each other. The opposite sets of blades are used, in sequence, to cut in opposite directions. This results in small, chopped-up bits of paper.

They also have mechanical or electrical timing mechanisms that ensure the blades continue moving at the right speed and tempo. These timing devices are attached to (and controlled by) the motor which drives the rollers. They ensure that all the parts of the machine work together correctly.

Micro-cut Shredders

micro cut blades

These can create pieces of paper that are even more finely chopped than the output of cross-cut shredders. Their output is as fine as confetti, and impossible to unshred. In operation, they are similar to cross-cut shredders. The only difference is that they produce tinier pieces.


Other than the basics of snatching and cutting, a paper shredder may also have extra mechanisms like sensors. Sensors let you know when there are paper jams, blade problems, or if the output container is full.


That’s how paper shredders work. The basic idea is that the machine snatches the paper, moves it, using rollers, and shreds it using serrated wheels or serrated blades.

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