Applied Mechanics and Materials Vol. 882

Abstract: This study is part of the project Smart Melting in the research cooperation Green Factory Bavaria (GFB). The main targets of the project are the improvement of the key figure OEE (Overall Equipment Effectiveness) and the reduction of the energy consumption in the non-ferrous die-casting industry. By implementing a software tool in the factory of an industrial partner, which collects the essential data to improve maintenance, a necessary requirement for an incident management is created. This article focuses on the current state of data acquisition in the plant of the industrial partner and the estimated potential of process improvement by an incident management system. The collected incident data of the producing die-casting machines are processed and analyzed. In the data analysis the incidents are classified according to their cause and assigned to the respective machine. The time to repair (TTR) and the time to failure (TTF) are investigated in order to obtain statistical probability distributions. The TTR is an exponentially distributed value and the TTF can be depicted using the Weibull distribution [1]. A simulation model based on statistically concentrated data is used to determine the effects of a better incident management on the key figure OEE. An improved maintenance reduces the number of incidents and increases the TTF. An improved incident management which shortens the downtime reduces the TTR. As a result of the improvements the availability factor of the OEE increases remarkably. Furthermore an increase of the quality factor (proportion of good parts) of the OEE can be expected.

Abstract: This paper describes the necessary measures to create an adaptable material flow and energy simulation for melting and die-casting plants. Based on two reference plants, the structural and intralogistical differences are emphasized and examined. These differences specify the necessary extensions to a previously created simulation environment in order to be able to analyze variable plant configurations. Special emphasis is put on the creation of a simplified energy model that allows the modeling of melting furnaces based on rudimentary datasets. Using the adaptable material flow and energy simulation two measures and their effects on the in-plant energy efficiency as well as productivity are analyzed. The simulation results suggest energy savings potentials for both plants and measures to increase productivity for one of the analyzed plants.

Abstract: Digital printing technologies are becoming increasingly important for modern electronics production. Besides inkjet printing for low viscosity inks, jetting of pasty materials such as PTF can be a viable alternative to traditional subtractive or additive metallization methods in the future. Hybrid printed electronics, a combination of printed circuitry with classical electronic components, offers many advantages such as low cost, environmental sustainability and others. Until now, the mechanical and electrical properties of printed pastes on molded substrates have not been investigated in detail, just as little as the long-term characteristics of interconnection technologies necessary to mount traditional electronic components onto printed substrates. In different test series, electrical resistance and adhesion of a special PTF material have been investigated. The long-term behavior of the material itself and three alternative interconnection technologies for mounting of SMT components has been evaluated. Results are encouraging, although still a lot of improvements are necessary.

Abstract: Electromagnetic actors (solenoids) are used in automotive and automation technology as valve actors for pneumatics and hydraulics or as actuating and pressure solenoids. During assembly there are often press-in and caulking processes used. A central quality aspect of the final control elements is the adherence to defined actuating force ranges in order to ensure the switching process and at the same time to keep wear within limits. These defined force ranges can currently only be maintained by additional heat treatment of the parts. The hysteresis of the assembled unit can be influenced by the caulking. The objective of this paper is to propose the potential reduction of annealing processes by revealing the interdependencies between the magnetic interactions of the individual components and the assembly process parameters. In addition, errors in the caulking process are detected and prevented at an early stage. A magnetic characterization of the soft magnetic components and assemblies before and during their assembly is proposed. Furthermore, the integration of the measurement data into a process control system is intended. The precondition is the development and construction of measuring equipment and systems that can be used to assess the magnetic properties at an early stage of assembly. The assembly can then be adjusted in order to compensate batch fluctuations. As a consequence new materials can be used to eliminate complex annealing processes prior to assembly.

Abstract: To measure the energy efficiency performance and the characteristics of electronic cooling fans a high-precision suction side test rig was designed according to the corresponding national DIN and international ISO standards. To evaluate the influence of the test rig design on the precision of the performance measurements of the fan, the complete test rig designs were analyzed in detail with the commercial CFD solver Star-CCM+ from Siemens PLM Software. Since at the test rig the pressure values of the fan are measured indirectly at the test rig chamber and not at the fan itself, the pressure values from the simulation as read out at the test rig chamber and at the fan itself were compared to deliver the required precision of the test rig design. Furthermore, the effect of the baffle plate and the throttle characteristics on the energy efficiency performance measurements of fans for electronic cooling have been analyzed.

Abstract: Process cooling and air conditioning are becoming increasingly important in the industry. Refrigeration is still mostly accomplished with compression chillers, although alternative technologies are available on the market that can be more efficient for specific applications. Within the scope of the project “EffiCool” a technology toolbox is currently being developed, which is intended to assist industrials users in selecting energy efficient and eco-friendly cooling solutions. In order to assess different refrigeration options a consistent methodology was developed. The refrigeration technologies are assessed regarding their efficiency, CO₂-emissions and primary energy consumption. For CCHP systems an exergetic allocation method was implemented. Two scenarios with A) a compression chiller and B) an absorption chiller coupled to a natural gas CHP system were calculated exemplarily, showing a greater overall efficiency for the CCHP system, although the individual COP of the chiller is considerably lower.