Patent ID: 8636497

Claim:
An extruder screw for a screw extruder for plasticising and/or transporting thermoplastic materials comprising at least one extruder cylinder, a material feed means and at least one extrudate discharge at the end of the extruder cylinder, that is remote from the material feed means, wherein the extruder screw has at least one screw flight including a screw land, forms an intake region and at least one transport and mixing region and provided in the transport and mixing region are means for shearing the extrudate, characterized in that the means for shearing the extrudate include at least one shearing land which extends over at least a third of a length of the extruder screw over the periphery thereof; and characterized in that the shearing land is formed in a manner of a screwthread land with a pitch angle extending in opposite relationship to the screw land; and characterized in that a height of the at least one shearing land continuously increases from the intake region in a direction towards an extrudate discharge.