Shredder

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Paper Shredder

Shredder scissors

Shredder scissors 4918-3.jpg
  • Small, light, cheap,
  • Convenient for minimal amounts of shredding
  • Can cross cut or strip cut

Manual shredder

Reduced size, 1 sheet only. Pretty limited.

Electric shredder

Domestic units have limited life, and low end units especially have short lives if more than one sheet is shredded at a time. Expect to need to open the thing up to remove jammed paper at some point.

Properties

  • Strip or crosscut - crosscut is more secure
  • Size of strips or pieces also determines security
  • Number of sheets taken in one go - usually not a good idea to exercise them on this point
  • Speed of shredding, but don't overvalue this as a shred speed that matches the pace at which you can hand feed sheets is typical.
  • How it handles staples (jams, stops, passes them whole or shreds them)
  • Some also chop CDs and credit cards
  • How it handles jams - some automatically reverse feed to clear a jam.

Shredded paper is used for animal bedding. Staples or pins must be removed to prevent injury. Questions were raised on uk.d-i-y about whether treated papers such as thermal printer paper paper might be ok for animals, so far we don't know.

End of life usually results from stripped plastic gear teeth. If the bad teeth are driven at low speed they can simply be cut off to enable a machine to carry on.

Alternatives

  • burn paper
  • microwave destruction of CDs


Garden shredder

Designed to shred tree prunings & sometimes weeds. Shredding turns the prunings into mulch.

Properties

  • Size limit - maximum wood size tends to be small with domestic units, often around an inch. The biggest units can swallow whole trees.
  • Noise - most garden shredders are extremely noisy, making ear defenders essential, and annoying neighbours
  • Mechanism type - some behave better than others
  • Blade replacement - usually blades are replaceable & cheap. They can normally be resharpened with an angle grinder several times before replacement.

Other uses

Garden shredders can also be used to shred used carpet to make fibres for concrete crackproofing. Clearly this is not a use recommended by manufacturers, and may invalidate guarantees.

  • Precut the carpet into narrow diagonal strips. They need to be diagonal to limit max thread length, otherwise the shredder mechanism ties up & jams.
  • Doing this by hand is hard going, an electric cutter makes it easy.
  • Feed the strips in one at once, it can be hard going for the machine.
  • Expect to need to open a jammed mechanism occasionally and cut threads out. Turn the power off quickly if it jams.

The resulting mixed fibres can be added to concrete to increase its tensile strength and counter cracking. Around 1% fibre is used for this. It's also possible to use the fibre with bitumen for roof repairs, at a much higher percentage. Synthetic fibres are best, wool pile or canvas backing fibre rots in time.

See also