University of Zwickau
University of Zwickau
Schumann C.-A.,University of Zwickau |
Forkel E.,University of Zwickau |
Klein T.,University of Zwickau |
Gerlach D.,Dimensional Technology International Inc |
Mueller E.,TU Chemnitz
SAE Technical Papers | Year: 2015
Total quality is becoming increasingly important for competitiveness. In order to achieve high quality, the requirements must be continuously compared with the results achieved in the process. This is done by means of measurement parameters and comparative values. The acquisition of the data requires appropriate measurement methods. The measurement methods and procedures have to be constantly developed in order to measure more precisely and to generate an even higher quality. Thus, the achieved product quality can be determined absolutely and relatively. If deviations from the planned quality parameters occur, the operator will be able to intervene immediately. The presented procedure is one of the noncontact (optical) measurement methods using CMMs, 3D scanners and 3D cameras. It is a combination of stereo photography and photogrammetry. The measurement system is designed modular from any number of camera-computer-units enabling the serial and parallel interconnection of various scanner modules to a matrix. Thus, the highly accurate measurement of three-dimensional surfaces is guaranteed in short time intervals. The measurements of three-dimensional surfaces are not spot-checked but they will be realized for each product performed in the cycle time of the system. This means continuous measurements in process will be possible. After pilot developments and investigations, the first applications will follow in the automotive industry and logistics sector now. The first part of the paper the measuring system will be briefly illustrated. In the second and main part the application development and preparation will be presented in the paper. Additional development potentials will be discussed. © 2015 SAE International.
Papenheim M.,University of Wuppertal |
Dhima K.,University of Wuppertal |
Wang S.,University of Wuppertal |
Steinberg C.,University of Wuppertal |
And 4 more authors.
Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics | Year: 2014
Relief of residual stress in an imprinted polymer may affect the replication fidelity by leading to recovery. The level of stress induced in the polymer depends on the method of imprint. For example, a "soft" imprint with an elastomeric stamp uses capillary forces to fill the cavities whereas a "hard" imprint with a rigid stamp relies on external pressure. To study the effect of residual stress after imprint, both methods are applied with different imprint times to vary the level of residual stress, as the stress remaining relaxes with imprint time. To visualize the residual stress a temperature treatment is performed after imprint. This temperature treatment allows recovery within a convenient experimental time. A comparison of the shape of the imprinted structures before and after temperature treatment clearly shows that with a hard imprint at short imprint times a considerable amount of stress remains in the polymer, in particular when the residual layer is thin and the imprinted stamp structures are wide. With a soft imprint residual stress is not evident. Similar results are obtained with a thermoplastic material and a crosslinking material (SU-8); however, with the latter recovery remains limited due to a decrease of mobility during crosslinking. Residual stress is of major importance for the replication fidelity with short imprint processes. © 2014 American Vacuum Society.