Parameters Of Thread Research Articles

Optimum Design on Trapezoidal Thread Parameters of Co-Rotating Twin Screw Extruder

In order to design trapezoidal thread parameters of co-rotating twin screw extruder that is used in non-fused materials processing, based on geometry of fully wiped co-rotating twin screw extruder by M. L. Booy, the paper adopts tangential approximation method to determine the parameters of trapezoidal thread choosing tangent of especial point of normal section curve. And reasonable spans of oblique angle, actual top width of flight, channel depth and thread lead are determined by the optimum design with objective function of maximal theoretical flux. Experiments show that a co-rotating twin screw pulping extruder of trapezoidal thread designed by the method is easier to machine and measure, and pulp processed by the twin screw pulping extruder can meet the quality requirements. Thus, twin screw designed by the method reserves the main strongpoint of the fully wiped co-rotating twin screw extruder.

Optical method of monitoring the geometrical parameters of thread, based on a study of Fraunhofer diffraction at a moving twisted thread

Optical method of monitoring the geometrical parameters of thread, based on a study of Fraunhofer diffraction at a moving twisted thread

Optical Testing of Bolt-Type Screws

The handling of standard components, for example screws. In automatic assembly lines often leads to trouble and, thus, to the stop of the assembly line due to the permitted fault rate of 2%. A 100-% inspection of the screws before assembly is desirable to reduce these stop periods. Studies showed that faults in assembly are 70% geometrical faults. The inspection jobs derived from fault analysis can preferrably be carried out with optical sensors by the silhouette procedure. Because of this trend, an electro-optical measuring system, composed of a process control computer directing a line scan camera and a linear guide driven by a step motor for axial translation of the screw, was built for fundamental examination. With this installation the geometry of the screw can be measured in meridional section, and the data can be stored in the computer. The developed information-processing programs permit, after an adjustment of the screw position according to software, a comparison of the stored sample and the measured object to be made. Because of this comparison and after a calculation of the parameters of the screw thread an appraisal of the fault is possible.