Influence of different polishing materials in the material removal of steel samples

The quality of injection moulded polymer optic parts depends on the surface finish of the respective mould. In order to improve and control the surface finish of the mould it is important to be able to keep the material removal constant during the polishing process of these moulds. This will provide a tactical material removal therefore allowing a controlled correction of the mould’s surface geometry. The aim of this work is to study the influence of different polishing materials in the material removal rate and its reproducibility during the polishing process of hardened steel. Different polyurethane polishing materials with different fillers were tested. It was observed that the filler material of the polyurethane is crucial in order to obtain constant and reproducible results. Experiments were carried out with an industrial robot and the material removal’s depth value was compared

Alignment model for trunk road network maintenance outsourcing

Road maintenance outsourcing is now the foremost strategy by which road authorities procure maintenance works. Despite growing application of road maintenance outsourcing, there are conflicting estimates on the effective­ness of road maintenance outsourcing and shortage of appropriate models to align over optimistic expectations of road authorities from road maintenance outsourcing with substantiated benefits. This paper investigates the efficacy of road maintenance outsourcing. In this paper, the different variants of road maintenance outsourcing and road maintenance works are evaluated with a SWOT analysis and a comprehensive literature review respectively. In addition, a road main­tenance outsourcing alignment model based on a decision tree and Balance Score Card is proposed and illustrated with a Nigerian trunk road network authority as a case study. The result of the SWOT analysis and comprehensive literature review establishes fresh insight into road maintenance outsourcing dynamics. The presented road maintenance outsourc­ing alignment model provides adequate pathways that could assist road authorities identify the most appropriate road maintenance outsourcing variant for road maintenance procurement. In addition it aligns actual benefits and expectations of road maintenance outsourcing and facilitates development of SMART metrics for effective assessment of road main­tenance outsourcing. The proposed model is applicable across other infrastructures. First published online: 01 Sep 201

Material removal simulation for steel mould polishing

The surface finish of an injection mould influences the quality of the moulded polymer optic parts. In order to improve and control the surface finish of the mould it is important to be able to predict the material removal during the polishing process of this mould. The aim of this work is to predict the material removal during the polishing process, comparing the results obtained from polishing attempts on steel samples and the results obtained from a simulation model. A simulation model is developed with the abrasive wear Holm-Archard equation in ANSYS. This simulation model will help to eliminate the iterative trial and error polishing, therefore facilitating the steel mould production

Ascertaining life cycle inventory data for electrical discharge machining

AbstractSustainable manufacturing systems require accounting for both product and process level environmental impacts. Established methods and databases are available for product level environmental impact assessment. However, there is a lack of data for process level or use phase assessments despite these being responsible for a significant share of the total environmental impact. This lack of data is even further exacerbated for unconventional machining (UCM) - unit process Life Cycle Inventory (LCI) data for UCM processes has particularly limited records in LCI databases. Electrical discharge machining (EDM), which is the most widely used UCM process, is reported as much less energy efficient compared to conventional machining processes. In addition to that, EDM produces wastes in solid, liquid, gas and aerosol form increasing its environmental footprint. The purpose of this study is to ascertain LCI data for EDM processes and thus to facilitate improved life cycle assessment during the use phase. The study takes insights of CO2PE!-methodology, a systematic inventory analysis of the use phase of manufacturing unit processes. Case studies are carried out with an industrial die and mould manufacturer. The resultant data for die sinking and wire EDM is then compared with publicly available data. Challenges of generalising LCI data are discussed with future improvement potentials