Remanufacturing in the Heavy Vehicle Industry—Case Study of a Finnish Machine Manufacturer

This study analyses remanufacturing operations of a Finnish heavy vehicle manufacturer with global operations. The company has remanufactured and refurbished certain components for a decade in a centralised remanufacturing and recycling centre in Finland, but it has encountered significant challenges, especially in reverse logistics. The company considers regional remanufacturing to decrease these disadvantages. The purpose of this study is to analyse the characteristics, challenges and benefits of regional remanufacturing by reviewing the relevant literature and analysing the empirical data, including a survey for international subsidiaries of the case company to determine regional needs. As a result, we have identified significant benefits, especially related to minimised logistics costs and better availability of the components, but also challenges, such as lack of resources, and insufficient economies of scale.

Process parameter determination for small recycling plants for the production of filament for FFF printing using the Taguchi method

With the increasing use of the filament fabrication process, the in-house production of filament and the recycling of PLA waste is becoming more and more important. Small desktop filament extruders with associated peripherals enable small businesses and private users to carry out these recycling processes. Determing the right process parameters is of crucial importance here. These are usually only issued by the polymer manufacturer and the machine manufacturer. However, the development of own process parameters is important for new polymer compounds, as well as polymers with unknown manufacturers, as is typical in recycling. The common Taguchi method, which is used for process optimisation within the FFF process, was also used in this article to produce improved parameter sets for the production of filament using a single screw extruder (3devo Precision) with four heating zones. In this experimental field, the Taguchi method did not prove promising. Due to the small dimensions and compact design of such desktop filament extrusion machines, it was found that the setting parameters cannot be considered independently. The main parameters influencing the process were identified as the extruder screw speed, the cooling capacity and the temperature of the heating coil at the hopper. Nevertheless, parameter sets for PLA pellets and recycled PLA could be developed which have a better performance in terms of homogeneity of the diameter over time compared to the previously available parameter sets.

INTERDISCIPLINARY SYSTEM ARCHITECTURES IN AGILE MODULAR DEVELOPMENT IN THE PRODUCT GENERATION DEVELOPMENT MODEL USING THE EXAMPLE OF A MACHINE TOOL MANUFACTURER

This paper considers the orientation of product development structures towards interdisciplinary system architectures using the example of a tool machine manufacturer. Due to the change from simple mechanical products to extensively designed systems, whose successful development requires the integration of all disciplines involved, it is analyzed which requirements there are for these interdisciplinary system architectures in today's development environment. In addition, it is validated on the basis of the investigation environment that interdisciplinary system structures are necessary for the development on the different levels of the system view. In doing so, the investigation environment addresses the concept of extracting customer-relevant features (systems) from a physical-tailored modular system (supersystem) in order to develop and test them autonomously, as well as to transfer them to the entire product range in a standardized manner. The elaboration identifies basic requirements for the development of a knowledge base in interdisciplinary system structures and places them into the context of an agile modular kit development.

Experimental investigation on the effect of platform heating on the dynamic mechanical properties of selective laser manufacturing of AlSi10Mg alloy

Additive manufacturing (AM) is one of the emerging promising technology technologies of manufacturing prototypes. The process of AM is based on melting powder by an energetic beam layer by layer to create a three-dimensional body. One of the lightweight alloys that is being used for AM is AlSi10Mg. The process of manufacturing is controlled by several tens of parameters most of which are determined by the machine manufacturer. One of the important parameters is the building platform temperature. In the present study we took samples from different heights of the building platform and measured the dynamic mechanical properties of each sample. It was noted that after a stress relief treatment (SRT) the difference in the static and dynamic mechanical properties along the building direction changed differently. The dynamic mechanical properties of samples that were fabricated in proximity to the building platform did not change after the SRT, while the mechanical properties of the samples that were fabricated far from the platform changed dramatically and became like those that were fabricated near the building plate.

Relationship between measured and prescribed dialysate sodium in haemodialysis: a systematic review and meta-analysis

Background Dialysate sodium (DNa) prescription policy differs between haemodialysis (HD) units, and the optimal DNa remains uncertain. We sought to summarize the evidence on the agreement between prescribed and delivered DNa, and whether the relationship varied according to prescribed DNa. Methods We searched MEDLINE and PubMed from inception to 26 February 2020 for studies reporting measured and prescribed DNa. We analysed results reported in aggregate with random-effects meta-analysis. We analysed results reported by individual sample, using mixed-effects Bland–Altman analysis and linear regression. Pre-specified subgroup analyses included method of sodium measurement, dialysis machine manufacturer and proportioning method. Results Seven studies, representing 908 dialysate samples from 10 HD facilities (range 16–133 samples), were identified. All but one were single-centre studies. Studies were of low to moderate quality. Overall, there was no statistically significant difference between measured and prescribed DNa {mean difference = 0.73 mmol/L [95% confidence interval (CI) −1.12 to 2.58; P = 0.44]} but variability across studies was substantial (I2 = 99.3%). Among individually reported samples (n = 295), measured DNa was higher than prescribed DNa by 1.96 mmol/L (95% CI 0.23–3.69) and the 95% limits of agreement ranged from −3.97 to 7.88 mmol/L. Regression analysis confirmed a strong relationship between prescribed and measured DNa, with a slope close to 1:1 (β = 1.16, 95% CI 1.06–1.27; P < 0.0001). Conclusions A limited number of studies suggest that, on average, prescribed and measured DNa are similar. However, between- and within-study differences were large. Further consideration of the precision of delivered DNa is required to inform rational prescribing.

Innovative Methods for Small Mixed Batches Production System Improvement: The Case of a Bakery Machine Manufacturer

One of the common problems of organizations with turn-key projects is the high scrap rate. There exist such traditional methods as Lean Six Sigma (LSS) and DMAIC tools that analyze causes and suggest solutions. New emerging intelligent technologies should influence these methods and tools as they affect many areas of our life. The purpose of this paper is to present the innovative Small Mixed Batches (SMB). The standard set of LSS tools is extended by intelligent technologies such as artificial neural networks (ANN) and machine learning. The proposed method uses the data-driven quality strategy to improve the turning process at the bakery machine manufacturer. The case study shows the step-by-step DMAIC procedure of critical to quality (CTQ) characteristics improvement. Findings from the data analysis lead to a change of measurement instrument, training of operators, and lathe machine set-up correction. However, the scrap rate did not decrease significantly. Therefore the advanced mathematical model based on ANN was built. This model predicts the CTQ characteristics from the inspection certificate of the input material. The prediction model is a part of a newly designed process control scheme using machine learning algorithms to reduce the variability even for input material with different properties from new suppliers. Further research will be focused on the validation of the proposed control scheme, and acquired experiences will be used to support business sustainability.

Ermittlung der Staubemissionen an Holz-Bearbeitungsmaschinen/Determining the dust emission of woodworking machines for risk assessment

Im Beitrag werden zwei Verfahren zur Ermittlung der Staubemission an Werkzeugmaschinen vorgestellt. Es werden das „gravimetrische Verfahren“ und die „Ermittlung des Erfassungsgrades“ beschrieben und gegenübergestellt. Das gravimetrische Verfahren zur Ermittlung des luftgetragenen Holzstaubs ist Stand der Technik zur Beurteilung der Staubemission von Holzbearbeitungsmaschinen. Dieses aufwendige Messverfahren mit Staub-Probenentnahmegeräten erlaubt eine Aussage über den Emissionsgrad der untersuchten Maschine. Dagegen quantifiziert die Ermittlung des Erfassungsgrades einer Bearbeitungsmaschine die Effektivität des Absaugsystems bei der Erfassung von Spänen und Stäuben. Ein Vergleich von Gravimetrie und Erfassungsgrad soll eine detaillierte Aussage zu den emittierten Späne- und Staubmengen von Bearbeitungsmaschinen für die Holz- und Holzwerkstoffbearbeitung liefern. Beim Messverfahren Ermittlung des Erfassungsgrades wird davon ausgegangen, dass Späne- und Staubfraktionen ähnlich gut erfasst werden können. Die genaue Zusammensetzung der erfassten und nichterfassten Materialanteile sowie der Partikelgrößen sind derzeit noch Gegenstand der Untersuchungen. Unbenommen davon müssen im Betrieb die nichterfassten Anteile aufwendig vom Benutzer in einem nachgelagerten Prozessschritt aufgesaugt werden. Es wird ausdrücklich darauf hingewiesen, dass die Untersuchung des Emissions- oder Erfassungsgrades einer Maschine nur eine qualitative Aussage zur Staubbelastung in der Umgebung einer Maschine erlaubt. Die Einwirkung beziehungsweise Exposition von Mitarbeitern hängt von Umgebungsbedingungen wie zum Beispiel Raumgröße, Luftwechsel, Sauberkeit, Leistung der Absauganlage, Beeinflussung durch Nachbararbeitsplätze (Bystanderexposition) und nicht zuletzt vom Handling des Bedieners ab. Diese Faktoren werden im Allgemeinen nicht von der Maschine beziehungsweise dem Maschinenhersteller beeinflusst.   This paper presents two methods for determining the dust emission of machine tools. The gravimetric method and the determination of the degree of collection efficiency are described and compared. compared. The gravimetric method for establishing airborne wood dust is state of the art for assessing the dust emission of woodworking machines. This complicated measuring method with dust sampling devices makes it possible to assess the emissivity of the examined machine. In contrast, establishing the degree of collection efficiency for a machining centre quantifies how efficient the suction system collects chips and dust. By comparing gravimetric analyses and the degree of collection efficiency, it is possible to provide a detailed assessment about the amount of chips and dust emitted by machining centres in the machining of wood and wood-based products. The measuring method for establishing the degree of collection efficiency assumes that chip and dust fractions can be collected similarly well. The exact composition of the collected and uncollected material fractions as well as the particle sizes still have to be examined yet. Irrespective of that, the uncollected particles have to be removed during operation in a subsequent, complicated process step by the user. It has to be emphasized particularly that by analysing the emissivity or the degree of collection efficiency of a machine it is only possible to qualitatively assess the dust exposure in the surroundings of the machine. The influence or exposure of workers depends on environmental conditions, such as e.g. room size, air change, cleanness, the efficiency of the suction system, the influence by adjacent machines (bystander exposure) and last but not least the handling of the operator. In general, these factors are not influenced by the machine or rather the machine manufacturer.

Compromise Optimal System Design for Solving Multi-Objective Green Supplier Selection Problems

Most instances like developing technology, scarce sources, and global warming have brought about an ongoing perspective with Sustainable SCM and Green SCM starting from Traditional SCM. Supplier selection in all these processes is a decision-making process playing a significant role in the success of enterprises. The most critical point in this decision-making process is the criteria used in the supplier selection process because they directly affect the selection of supplier that is appropriate for the strategy of the enterprise. In this chapter, the optimal quantity of products to be purchased from suppliers were determined through a solution offer that authors named as compromise optimal system design. For the recommended solution, first, a new model was introduced by arranging Multiobjective Supplier Selection problem based on the De Novo assumption, and then Compromise Programming was used for the solution of this model. The developed solution procedure was used to determine the amount of blending machine to be purchased from the green supplier of a milling machine manufacturer.