The most widely used Wood Chippers are of the 'Flywheel' (conventional flat blade) principle, these use 2, 3, 4 straight knives bolted to a flywheel type structure which rotates at high speed, the knives pass close to a shear bar or anvil which holds the material to be chipped as the knives pass.
For efficient chipping it is essential to have sharp knives, providing contaminated material is not put through the machine, knives will require sharpening every 25 - 30 hours.
2 powerful infeed rollers are desirable for professional users to ensure difficult material is pulled into the machine and forced against the knives.
Some Chippers have problems with green wet conifer and similar material, a powerful air blast is vital to avoid blockages and to discharge the material into a vehicle or skip.
The 'Disc Blade' system uses 100mm (4-inch) diameter high grade steel discs, their curved edge 'slices' the wood, making them less susceptible to damage and 3 Db quieter.
The Disc Blade can be rotated as the edge in use becomes blunt or damaged, dramatically reducing operating costs and downtime.
When having a demonstration be sure to test the machine on all the types of material you are likely to require chipping.
Don't buy a chipper if the material is contaminated with soil, stones, nails etc. or is wet soggy green waste material.
Drum Type
One of the earliest Chipping principles producing a larger chip than the most popular flywheel type machines.
Screw Type
Developed in Scandinavia, produces a larger chip and mostly fitted to tractors. These machines are not fitted with feed rollers and the material cannot be 'Reversed' or 'Stopped' from entering once engaged.
Flywheel (conventional flat blades)
Most widely used principle to date with 2, 3, 4 straight blades, either 'Self or Roller Feed'.
Flywheel (Disc Blade)
The patented Disc Blade system developed by GreenMech gives improved performance, reduced power & costs.