A typical characteristic of printing machines is their high level of exploitation. But modern offset presses are as well large and complex mechanical systems that use energy in a large variety of electrical drives, fo...
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ISBN:
(纸本)9783642290688
A typical characteristic of printing machines is their high level of exploitation. But modern offset presses are as well large and complex mechanical systems that use energy in a large variety of electrical drives, for heating, air conditioning and drying. Increasing energy prices make the reduction of energy consumption in the operation of printing presses a highpriority, market-relevant issue with an initial target of around 15 %. General and new engineering knowledge provides a variety of possible approaches for reducing energy consumption. The goal is to find an optimal compromise between additional, cost-creating measures for the machine builder and real cost-reducing benefits for the end user.
The engineering of artificial tissue and organs is widely gaining relevance in biotechnological and biomedical research. Particularly by the law enforced reduction of animal testing, alternative methods need to be dev...
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The engineering of artificial tissue and organs is widely gaining relevance in biotechnological and biomedical research. Particularly by the law enforced reduction of animal testing, alternative methods need to be developed to simulate and test the effects of chemical substances on human organs. Regarding the branches for pharmaceuticals, chemicals and cosmetics most products need to be tested on penetration of the human skin tissue. As an alternative method to animal testing, skin equivalents (SEs) based on tissue engineering may be used to test the skin barrier function. In the framework of a large scale research project, we built a fully automated production process based on the adaption of manual laboratory protocols to carry out the biological process steps for the manufacturing of SEs. In a first step, keratinocytes are mechanically and enzymatic isolated from human foreskin biopsies. In a second process, the cells are cultivated in MTP format cultivation dishes und undergo a series of passages. In a last process step, the keratinocytes are concentrated and dispensed in 24 well membrane based MTPs. Due to biological fluctuations in cell and tissue growth, the production process faces major challenges to control and process a vast variety in batch duration and timing. This results in a strong impact in the final tissue quality. For quality control in the manual process, histologies of the SEs are prepared followed by staining and microscopic imaging. To overcome this time intensive process, we developed a fully automated optical coherence tomography OCT system. OCT is a non- invasive and non-destructive imaging technique based on the interferometric detection of optical light feedback from the probe tissue in the near infrared light. OCT generates 2D and 3D tomographic images with a micron resolution and a tissue penetration up to 2 mm. We developed custom image processing algorithms, to detect the individual layer structure and corresponding layer thicknesse
In this paper the impact of different tool materials, tool coatings, and lubricants onto the micro forming process of micro cavities is investigated. As tool materials two different hardened steels were used for the f...
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ISBN:
(纸本)9780956679000
In this paper the impact of different tool materials, tool coatings, and lubricants onto the micro forming process of micro cavities is investigated. As tool materials two different hardened steels were used for the forming die. To lower the friction and adhesion between forming tool and aluminium substrate three coatings TiN (titanium nitride), TiCN (titanium carbon nitride), and DLC (diamond like carbon) were tested. Furthermore, the influences of different lubricants were studied. Geometric parameters and surface quality were judged by laser microscopy and SEM images of metallographic sections.
Data integration between different life cycle stages of a production system is a crucial requirement for the realization of continuous computer support what is often referred to as the Digital Factory. This paper pres...
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Data integration between different life cycle stages of a production system is a crucial requirement for the realization of continuous computer support what is often referred to as the Digital Factory. This paper presents an approach that leverages planning data within the operation phase of a production system by applying Semantic Web technologies and linked data concepts.
machine tool performance, production accuracy and energy efficiency are interdependent design criteria. To solve this design conflict, bionics – this means technical interpretation of long-term optimized biological p...
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machine tool performance, production accuracy and energy efficiency are interdependent design criteria. To solve this design conflict, bionics – this means technical interpretation of long-term optimized biological principles – could be an effective way to accelerate innovation loops in modern machine tool development processes. In the paper, these aspects will be discussed, and selected solutions will be presented in detail.
The main goal in manufacturing is to minimize production time, cost, energy and resources while maintaining or even improving performance. The main influence on process efficiency in metal cutting can be related to th...
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The main goal in manufacturing is to minimize production time, cost, energy and resources while maintaining or even improving performance. The main influence on process efficiency in metal cutting can be related to the machining parameters, while performance also depends on the material behavior such as strain rate, machining temperature and cutting forces. In the past, industry was searching for higher efficiency mainly by using higher production rates, achieved with higher cutting conditions. However, during the last decade the production process chain has been controlled more and more by the near-net-shape of semi-finished components and the use of high performance processes. This paper presents established and new applications of process modifications, substitutions, optimizations as well as the use of hybrid processes. In high performance cutting (HPC) additional elements play an important role, for example tool design and tool material, wear and tool life, coolant strategies, including dry cutting, MQL, cryogenic and high pressure flushing as well as the machine tool properties. Furthermore, this paper presents and discusses examples of the influence of process parameters in turning, milling, drilling, grinding and impact cutting under HPC conditions on the energy and resources efficiency in the automotive, aerospace, dies and moulds, micromachining and heavy duty industries.
According to an international status report, up to 70% of the errors in cutting production can be traced back to time- and process- dependant temperature fluctuations. In particular, thermal effects from processing le...
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According to an international status report, up to 70% of the errors in cutting production can be traced back to time- and process- dependant temperature fluctuations. In particular, thermal effects from processing lead to the deformation of machine components. This affects the tool and the workpiece. This paper considers the research into interactions between process-related and thermal deformations with a focus on the high-precision machining of large workpieces. Previously conducted investigations have demon- strated the effects of the heat flow into the structures of workpieces during the machining process. As one might expect, deforma- tion occurs, which leads to deviations in shape and position. In the same way, length changes due to process-heat transfer can be observed on the tool side. This leads to displacements of the centre point of the tool, which are dependent on the tool geometry and process parameters. However, resulting production errors can often be reduced by improved process control. Considering an exam- ple from the field of mould construction, this problem has been discussed from a practical perspective. Starting with experimental analyses, the heat flow into the workpiece related to the inherent deformation was measured. This was realised using thermographic systems and displacement sensors. Relevant parameters that have a significant influence on the process were to be identified in these tests. Heat-transfer effects were analysed while varying these parameters. In the same way, this should provide support for simulative analyses and facilitate the verification of these analyses. Using computer models, it was possible to detect and evaluate thermoelastic displacements before the processing. Based on this, the findings led to appropriate countermeasures, such as the use of a modified machining sequence. The aim of all of these investigations is the development of optimal machining strategies t o help reduce manufacturing errors.
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