Patent ID: 6848639

Claim:
An extruder cutting blade comprising: a blade body connection portion; a blade body portion with a leading edge with a cutting blade portion and an upper leading surface and a lower leading surface extending from said leading edge to an upper transition zone and a lower transition zone respectively provided followed by an upper trailing surface and a lower trailing surface respectively and a blade body trailing edge and the upper and lower trailing surface extending from said upper and lower transition zone respectivley to said trailing edge, said upper and lower trailing surface conversing at said trailing edge, the upper trailing surface leading from the upper transition zone to the trailing edge is formed so as to be curved as it converses with the lower trailing surface and the lower trailing surface is formed as a curved surface with a first curved part and a second curved part, whereby the two curved portions with different centers of curvature form a curved trailing surface with the degree of convergence with the upper trailing surface increasing toward the trailing edge.