Apparatus and method for shredding insulation

A machine for shredding material, comprising:

• a housing having an inlet for the material;
• a blade assembly positioned within the housing adjacent the inlet, the blade assembly being rotatable about an axis defining a flow direction for the material, whereby rotation of the blade assembly induces material fed through the inlet to the housing to flow along the axis towards one end of the blade assembly,
• the blade assembly having a plurality of generally radially extending knife blades arranged in a helix about the axis, the knife blades each being relatively planar and having a leading cutting edge and a trailing edge,
• each of the knife blades being disposed generally transversely to the axis but being rotated about a radial line drawn from the axis through the blade such that the cutting edge of the blade is positioned relatively further toward the one end of the blade assembly than is the trailing edge thereof, the blade assembly being operable to catch the material fed into the housing and move it in the flow direction, the rotated trailing edges of the knife blades serving to decrease the speed of movement of the material in the flow direction;
• and
• an obstruction member connected to the housing adjacent the blade assembly, the obstruction member comprising a fixed member having fingers interdigitated with the blades of the blade assembly, the obstruction member obstructing the insulation caught on the rotating blade assembly, whereby the blades shred the material.