Automation improvement of indirect gravure printing with a focus on the mechanical characteristics of silicone rubber pads

• Main Author: Hakimi Tehrani, Arash
• Format: Others
• Language: en
• Published: 2019
• Online Access: https://tuprints.ulb.tu-darmstadt.de/8322/1/Thesis_Arash_Hakimi.pdf; Hakimi Tehrani, Arash <http://tuprints.ulb.tu-darmstadt.de/view/person/Hakimi_Tehrani=3AArash=3A=3A.html> (2019): Automation improvement of indirect gravure printing with a focus on the mechanical characteristics of silicone rubber pads.Darmstadt, Technische Universität, [Ph.D. Thesis]

The main goal of this dissertation was an improvement in the automation level of the indirect gravure printing process. A type of indirect gravure printing with the name translational pad printing was considered in this dissertation as the printing process. This type of printing is used to print on 3D objects with concave and convex surfaces. For example, it can be used to print electroluminescent (EL) panels on the curved surface of a glass jar. In the first step, the automation level of the indirect gravure printing machine was improved. In this case, the structure of the indirect gravure printing machine was classified according to the structure of a mechatronic system. National Instrument CompactRio 9074 and Kollmorgen AKD servo drives were used as hardwares of control unit. LabVIEW and DIAdem software were applied to control the process and monitoring of data (online and offline), respectively. In the second step, an automation development was achieved according to implementation of manufacturing execution system (MES) and computer aided engineering (CAE). In this case, the silicone rubber material model as a hyperelastic material for different hardnesses was achieved according to test results of uniaxial tensile, compression and planar tests for hardnesses of 3, 6, 12 and 18 Shore A. The silicone rubber material model for different hardnesses was used to perform the simulation of the printing process. Mathematical equations of the pad geometry were calculated. Afterwards, a pad calculator to calculate the pad parameters was programmed for the first time. Also, a designing method of pad and a cost-efficient method for mold production of pad were described. As an innovative method, a stereolithografic 3D printer was used to prepare the pad molds. This method made the mold preparation more cost-efficient than before. So, this feature leads to manufacturing of unique pads according to printing conditions. Further, the printing process was simulated in finite element method (FEM) software ABAQUS. The simulation of the printing process helps to achieve suitable printing parameters for different conditions of printing. The ability of cost-efficient unique pad production and simulation of printing led to optimization of the printing process according to printing conditions. These features led to increase the automation level of indirect gravure printing from level 1 (before this thesis) to level 3.