Extruder Alignment

Besides from abrasive or corrosive filler material, also bad alignment of extruder components to the extruder center axis can be a reason for higher wear of extruder screws and extrusion parts. In this case, extruder components are not aligned centrically to the output shaft of the gearbox. This leads to partial wear on the extruder screw or extruder components, i.e. the metal surface of these parts is abraded. In worst case, the customer will then find metal chips in their compounds.
A wrong alignment of 0,1 mm at the gearbox contact surface (at an extruder length of approx. 2 meters) leads to an excentricity of 0, …. at the extruder end. If the extruder length is 4 meters, the excentricity value amounts to 0, mmm already.

These alignment faults can only be measured by the help of optical measuring systems.

When aligning an extruder, an optical measuring system (alignment telescope) is positioned in the gearbox output shaft at the back of the gearbox. Then, a movable reticule (collimator) is pushed through the extrusion head into the extruder front barrel. After having determined the extruder center, the deviations in the horizontal and vertical axis to the center of the gearbox output shaft are determined by means of micrometer drums. The position of the extruder parts towards the center of the gearbox output shaft are measured continuously at several measuring points in the extruder.


When the deviations in alignment between extruder components and extruder center have been measured, the extruder parts and components are aligned in horizontal and vertical direction by means of fastening and alignment bolts as long as they are positioned correctly to the gearbox output shaft.