Oberflächen‐ und Dünnschichtanalytik – unverzichtbares Werkzeug für Schichtentwicklung und ‐produktion

Surface and thin film analysis – indispensable tool for coating development and ‐production Development and production of thin films for functional coating on special materials is unalterable combined with a permanent quality control and therefore use of sophisticated analysis and measurement techniques. The field of interest is belonging to all steps of the production chain, starting with the characterization of the substrate surface (e. g. glass, plastics), followed by polishing and cleaning processes up to depth profiling of complex multilayers. The typical analyses are focused onto topographical and chemical features and their influence onto the product functionality. The use of surface and thin film analytics for problem oriented characterization is demonstrated by a few examples, which deal with surface roughness, contamination, impurities and dopand profiles as well as composition variations in the surface near region.     

食品红外辅助冷冻干燥技术的研究进展

目的概述红外辅助冷冻干燥技术在食品干燥中的研究进展,旨在为红外辅助冷冻干燥技术的选用以及工业化应用提供借鉴和理论支持。方法通过归纳总结国内外的最新研究进展,对红外辅助冷冻干燥技术的机理、红外辐射器波长和温度、食品干燥过程的预测以及对最终品质的影响等进行论述,并且提出改进措施。结果红外辅助冷冻干燥技术的发展潜力巨大,目前研究还处于初级阶段,其中控制红外辐射器温度、波长,监测干燥过程,以及建立适当的动力学模型是实现工业生产规模化的最新研究方向。结论红外辅助冷冻干燥技术可以有效地降低系统能耗,提高产品质量,具有很大的研究价值,新的研究方向具有很大的发展前景。     

Implementation of a process analytical technology system in a freeze-drying process using Raman spectroscopy for in-line process monitoring

The aim of the present study was to propose a strategy for the implementation of a Process Analytical Technology system in freeze-drying processes. Mannitol solutions, some of them supplied with NaCl, were used as models to freeze-dry. Noninvasive and in-line Raman measurements were continuously performed during lyophilization of the solutions to monitor real time the mannitol solid state, the end points of the different process steps (freezing, primary drying, secondary drying), and physical phenomena occurring during the process. At-line near-infrared (NIR) and X-ray powder diffractometry (XRPD) measurements were done to confirm the Raman conclusions and to find out additional information. The collected spectra during the processes were analyzed using principal component analysis and multivariate curve resolution. A two-level full factorial design was used to study the significant influence of process (freezing rate) and formulation variables (concentration of mannitol, concentration of NaCl, volume of freeze-dried sample) upon freeze-drying. Raman spectroscopy was able to monitor (i) the mannitol solid state (amorphous, alpha, beta, delta, and hemihydrate), (ii) several process step end points (end of mannitol crystallization during freezing, primary drying), and (iii) physical phenomena occurring during freeze-drying (onset of ice nucleation, onset of mannitol crystallization during the freezing step, onset of ice sublimation). NIR proved to be a more sensitive tool to monitor sublimation than Raman spectroscopy, while XRPD helped to unravel the mannitol hemihydrate in the samples. The experimental design results showed that several process and formulation variables significantly influence different aspects of lyophilization and that both are interrelated. Raman spectroscopy (in-line) and NIR spectroscopy and XRPD (at-line) not only allowed the real-time monitoring of mannitol freeze-drying processes but also helped (in combination with experimental design) us to understand the process.     

Powder form and stability of Pluronic mixed micelle dispersions for drug delivery applications

The aim of this work was to optimize a formulation of the Pluronic® F127/L121 mixed micelle system and evaluate it in terms of stability upon dilution in biologically relevant media and to explore the possibility of preparing F127/L121 micelles in a powder form that can be simply reconstituted to an initial freshly made mixed micelle formulation. The mixed F127/L121 micelles were prepared at a relatively high concentration of Pluronics (1% w/w for both Pluronics) using two different methods (direct dissolution and film rehydration) with an external input of energy. The optimal preparation of the mixed F127/L121 micelles (hydrodynamic diameter (d_h)?=?75?nm, polydispersity index (PDI)?=?0.287) was achieved using the film rehydration method followed by ultrasonication. Stability studies of the F127/L121 micelle system were performed at 25?°C and 37?°C and upon dilution in different biologically relevant media. The F127/L121 micelles were stable in phosphate buffered saline (PBS) upon 100-fold dilution for at least 10?d and in PBS containing bovine serum albumin upon 10 and 50-fold dilution for at least 48 and 12?h, respectively. A dry powdered form of the mixed micelles was prepared by freeze-drying after slow or fast freezing process. The influence of the type and amount of cryoprotectant on the prevention of F127/L121 micelles aggregation during the freeze-drying and reconstitution processes were evaluated. The use of trehalose (5%, w/w) and sucrose (2.5%, w/w) with slow and fast freezing process, respectively, resulted in a reconstituted product with mostly similar d_h and PDI values of the fresh micelle formulation.     

Detection of interferences in an additive manufacturing process: an experimental study integrating methods of feature selection and machine learning

Additive manufacturing becomes a more and more important technology for production, mainly driven by the ability to realise extremely complex structures using multiple materials but without assembly or excessive waste. Nevertheless, like any high-precision technology additive manufacturing responds to interferences during the manufacturing process. These interferences – like vibrations – might lead to deviations in product quality, becoming manifest for instance in a reduced lifetime of a product or application issues. This study targets the issue of detecting such interferences during a manufacturing process in an exemplary experimental setup. Collection of data using current sensor technology directly on a 3D-printer enables a quantitative detection of interferences. The evaluation provides insights into the effectiveness of the realised application-oriented setup, the effort required for equipping a manufacturing system with sensors, and the effort for acquisition and processing the data. These insights are of practical utility for organisations dealing with additive manufacturing: the chosen approach for detecting interferences shows promising results, reaching interference detection rates of up to 100% depending on the applied data processing configuration.     

A design protocol for tailoring ice-templated scaffold structure

In this paper, we show, for the first time, the key link between scaffold architecture and latent heat evolution during the production of porous biomedical collagen structures using freeze-drying. Collagen scaffolds are used widely in the biomedical industry for the repair and reconstruction of skeletal tissues and organs. Freeze-drying of collagen slurries is a standard industrial process, and, until now, the literature has sought to characterize the influence of set processing parameters including the freezing protocol and weight percentage of collagen. However, we are able to demonstrate, by monitoring the local thermal events within the slurry during solidification, that nucleation, growth and annealing processes can be controlled, and therefore we are able to control the resulting scaffold architecture. Based on our correlation of thermal profile measurements with scaffold architecture, we hypothesize that there is a link between the fundamental freezing of ice and the structure of scaffolds, which suggests that this concept is applicable not only for collagen but also for ceramics and pharmaceuticals. We present a design protocol of strategies for tailoring the ice-templated scaffold structure.     

The decoupling of product and process life cycles

When should a plant, if ever, adopt more flexible forms of production technology? The factors supporting the decision for a dedicated system are often based on the dedicated technology's lower fixed and variable costs with respect to production volumes. In. many industries, it is clear that such cost-reduction techniques are essential to a firm's success. On the other hand, flexible manufacturing systems, though initially more expensive, eliminate the requirement for an immediate investment in a new process once the life span of a particular part or product has ended. Given these fundamental differences, it is clear that the question of whether a firm within an industry should select a manufacturing technology which is highly flexible or dedicated can be key to its long-term success. To gain a reasonable understanding of which decision is best, it is imperative that the relationships between innovation, market, and production costs be understood and quantified. The aim of this report is to analyse these vital connections in an attempt to shed further light on these questions. In this context, we introduce the notion of ‘fast response process capability’ as an alternative to the dynamic model of product and process innovation cycles introduced by Utterback and Abernathy (1975). We argue that this new framework will have a large strategic implication across the industry.     

真空热处理炉内污染分析及清除措施

铁、镍基高温合金在真空热处理时往往表面生成少量氧化物，影响产品表面质量、抗拉强度及频率，其原因在于炉内存在气体污染。本文针对这一难题做了技术分析，找出了清除污染的措施，得出解决问题的办法。     

Automated production processes in the rotor blade industry – Solutions for a continuous direct textile layup

Recent efforts concerning the automation of production processes for wind turbine rotor blades involve several new challenges. The technical fabrics used present specific features in handling due to their limp characteristics. Because of the steady growth of modern offshore wind turbine dimensions, larger rotor blade mold surfaces have to be covered with technical fabrics which influence the size and the weight of the handling systems used for automation. For an economic production of future wind turbine types, an increase in efficiency – by shortening the process cycle times – is crucial. Consequently, the time‐consuming process steps need to be automated. The article focuses on the continuous direct textile layup process and delivers ideas and solutions for the resulting challenges of process steps like storing, cutting and draping a technical textile in an automated rotor blade production.     

排气式双螺杆挤出机直接制片生产双轴拉伸聚酯薄膜

排气式双螺杆挤出机中，设计有多个专门排气的系统，把聚酯在挤出机中熔融过程分离出来的水分和低分子挥发物全部排走，可以省略常规聚酯薄膜生产线中的聚酯切片结晶干燥工序，因此可大大节省建设投资．还可以显著提高产品质量．增加生产效益．这项新技术已在杭州大华塑业有限公司投产运行．     

Manufacturing‐induced surface contaminations

In the course of classical optics manufacturing glass components are in permanent direct contact with aqueous operating materials. Such contact leads to a certain absorption of water and hydrogenous compounds that may induce severe glass defects. In this contribution, absorption of hydrogen and other contaminants during grinding of glass was observed and qualitatively detected via laser‐induced breakdown spectroscopy. It is shown that hydrogen, calcium, magnesium, and carbon are implanted into the glass surface where the contaminant concentration increases over grinding time or contact time of the glass surface with water and the grinding tool, respectively. The contaminants hydrogen, calcium, and magnesium can be attributed to the water used as lubricant. In contrast, carbon most likely originates from wear debris of the used silicon carbide grinding pads. Several possible mechanisms that lead to such surface contamination of glasses during grinding – diffusion, accumulation in micro cracks as well as the formation of hydrated silica – are finally introduced.     

MOCH-Methode – ein Beitrag zur Haftungsbestimmung von Schichten

MOCH-Method – a Contribution to the Determination of Adhesion of Coatings A method is proposed to determine the fracture mechanics characteristics. A ?crack”? is produced in a well defined area by partial contamination. K- and G-factors are calculated by the compliance method. The fracture surfaces are investigated.     

Membranbälge für die Vakuumindustrie in verschiedenen Sauberkeitsstufen

Edge welded bellows for the vacuum‐industry in different cleaning levels — Controlled, measurable purity for all markets The more and more demanding cleanliness specifications of the vacuum industry, especially semiconductor production, are a major challenge for the manufacturing and cleaning processes of suppliers in this market segment. Also the COMVAT AG as a manufacturer of edge welded bellows, used in the vacuum industry e.g. as a flexible sealing elements, faces up to the increased requirements of its customers. For this purpose, the entire process chain has been optimized from the design of the product over the manufacturing and final cleaning to the inspection and packaging in clean rooms up to ISO class 5 according to EN ISO 14644‐1. The installation of three cleanliness levels ?Standard”?, ?Advanced”? and ?High‐Purity”? allows supplying the suitable purity to the customers. Their specifications regarding the contamination classes of organic, inorganic (metals and ions) and particles were observed. The highest cleanliness grade, the high purity level, is achieved by a high‐quality ultrasonic wet cleaning process, optimized especially for the cleaning of edge welded bellows.     

3D打印技术对产品的影响

目的研究3D打印技术性因素对产品从内在概念到外在结构与形式的影响,科学地认知该技术在设计方面的价值。重点研究在3D打印技术背景下产品属性及价值、生产与制造、设计、结构与形态等诸方面呈现出新的变化趋势。方法通过对"商品"与"产品"概念变迁的阐述,揭示3D打印技术影响下产品价值与内涵的变迁形式。分析3D打印技术对产品生产制造、造型与结构等方面的影响,进一步理清3D打印技术对产品、产品设计与生产、产品结构与形态等方面影响的形式与程度。结论 3D打印技术在设计范畴、设计观念、设计核心问题等方面突破了传统的设计认知藩篱。通过梳理新技术对产品多方面的影响,从而建立起新技术背景下的设计认知,以实现技术价值与创新设计价值的进一步融合。     

角膜真空冷冻干燥实验的传热传质分析

为保持角膜在真空冷冻干燥（以下简称冻干）过程中的活性,减少其内皮细胞的损伤,本文分析了冻干实验中前处理、预冻、干燥和复水检测等过程中,传热传质规律对角膜内皮细胞造成损伤的原因,在改进工艺参数的基础上,成功的冻干了合格的角膜。     

A step forward towards the development of stable freeze-dried liposomes: a quality by design approach (QbD)

This study highlights the advantages of using a Quality by Design (QbD) approach in order to gain a more comprehensive understanding of the freeze-drying process of pravastatin-loaded long-circulating liposomes (LCL-PRAV). Within the QbD paradigm, the present study aimed to establish the design space for the optimization of freeze-dried LCL-PRAV by means of Design of Experiment (DOE). The encapsulated solute retention (ESR), the average particle size, and zeta potential after freeze-drying, the residual moisture content, the macroscopic cake appearance, the glass transition temperature (T_g) of the freeze-dried cake, and the primary drying time were defined as critical quality attributes (CQAs) for the freeze-dried final product. Further on, the influence of lyoprotectant type, freezing rate, shelf temperature during primary drying, and the presence of an annealing step on the CQAs was investigated through a 21-run D-optimal experimental design. Three-dimensional response surfaces were generated to complete the statistical analysis and for a better understanding of the influence of variables and their interactions on the responses. The developed model was then used to build the design space for the freeze-dried liposomes, within which the product quality was assured and the process variability was minimized.     

食品真空冷冻干燥过程工艺参数分析

针对目前国内冻干食品企业制定食品冻干工艺和食品冻工设备设计需要,系统分析了食品真空冷冻干燥过程的主要工艺参数及其之间的关系; 为冻干食品企业制定食品冻干工艺及食品真空冷冻干燥设备工程设计确定技术参数提供参考。     

网带干燥技术在氨基模塑粉生产中的应用

简要介绍氨基模塑粉的发展概况,阐述氨基模塑粉生产工艺流程、主要生产设备,着重讨论控制氨基模塑粉生产质量的干燥技术,比较厢式烘干技术和网带烘干技术对产品质量影响,尤其是能耗的比较。结果表明:采用网带烘箱干燥技术可以大大地提高产品的质量和稳定性,为企业节约大量的能量,降低生产成本。     

Low temperature vapor-phase preparation of TiO2 nanopowders

The preparation of TiO₂ nanopowders by vapor-phase hydrolysis of TiCl₄ below 600°C is studied in this paper. Influences of preparation variables, such as preparative temperature, residence time, reactant concentration, and H₂O/TiCl₄ mole ratio, on TiO₂ particle size, morphology and chlorine contamination are investigated, followed by discussion. It shows that the hydrolysis temperature exerts greatest influences, while the residence time hardly have impact on product particles below 400°C, among the hydrolysis variables investigated. The chlorine contamination on nanopowders occurs during the preparation which can be greatly reduced by proper control on preparation variables. Unlike the high temperature gas-phase processes such as oxidation route and flame synthesis, low-temperature route shows the ready control on product powders, and thus obtains titania powders with small size, narrow size distribution and very weak agglomeration. In addition, the decreased energy consumption, retarded corrosion on the reactor and the reduced operation problems would be expected for the low temperature processes.