Wood Chippers

Most conventional Wood Chippers use a 'Flywheel' flat blade principle, with 2, 3 or 4 straight knives bolted to a heavy metal disc that rotates at high speed. These knives pass close to a shear bar or anvil, which holds the material to be chipped in their path.

For efficient chipping sharp knives are essential. Providing contaminated material is not put through the machine, these knives should last 25 - 30 hours between sharpenings.

In most professional machines, two powerful infeed rollers ensure difficult material is pulled into the chipping mechanism and forced against the knives.

Because some Chippers have problems with green, wet, conifer and similar material, a powerful air blast is vital to avoid blockages and to discharge material safely into a vehicle or skip.

In place of single edged knife blades, GreenMech developed the 'Disc Blade' system that uses 100 mm (4-inch) diameter high grade steel discs. Their sharp, curved edges 'slice' the wood, making them less susceptible to damage and 3 Db quieter.

As the edge in use becomes blunt or damaged, the Disc Blade can be rotated, without removing it completely. This dramatically reduces operating costs and downtime.

Choosing what is best for you

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.

The main types of chipper are:

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.

GREENMECH CHIPPER CM260MT70

Green Waste Shredders

The most widely used 'shredding' principle is the 'Hammer Mill', using a series of metal strips arranged on a shaft that rotates at high speed. The material is 'hammered' against a curved plate, normally no more than 60 cm (24") wide, with various size holes (screen) through which the material is forced.

There are also 'Flail" type shredders, generally used on wider bodied machines. These have a high speed rotor to which are mounted 'Flails' of various size and shape, material is loaded into a hopper and conveyed into the Flails which 'shred' the material, in some cases it is also forced through a screen and either deposited on the ground or conveyed upwards and discharged into a pile, lorry or skip etc.

'Flails' per ton of material probably requires up to 300% more HP than 'Chippers'.

'Tub Grinders' were developed in the USA to reduce the 'Volume' of construction site waste, most use a heavy rotor with rigidly mounted hardened steel projections which 'Grind' the material against heavy variable size 'Screens', material is loaded into a 'Tub' above the rotor, typically they use 300 - 600 hp.

The patented 'Disc-Shred' system, developed by GreenMech, comprises a series of discs on a shaft that rotates inside a drum. The discs are angled to 'auger' the material towards and through a screen into the rear of a chipper flywheel and discharge chute.

The discs can also be rotated as the edge becomes blunt or damaged.

All forms of 'Green Waste' material can be processed.

Choosing what is best for you

Don't buy a shredder if it is tree branches and scrub material not contaminated with soil, stones, metal etc.

The main types of shredder are:

Hammer Mill

A system used for many years in Agriculture, material is shredded and forced through a screen.

Tub-Grinder

Developed in the USA to reduce all forms of waste normally 300 - 600 hp.

Flail Type

Various types of 'Flail' designs with 'infeed' conveyor, variable screen and discharge elevator.

Disc-Shred

Developed by GreenMech from its unique Disc Blade system to provide improved performance, using less power and reduce operating costs.

GREENMECH ECO-COMBI SHREDDER- CHIPPER CM260MT70