22 research outputs found
Empirical evaluation of spin-on-glass-layers on steel surfaces by wear tests
Dies and moulds with high precision surfaces are being used in various branches, e.g. in the plastic industry where the surface finish are conventionally performed by manual polishers. With ever increasing demands of shorter lead times and reduced costs, efforts have been made to automate this finishing process. This paper presents an empirical study performed to test durability properties of SOG (spin-on-glass)-layers on steel surfaces. The results showed that the thin coating last longer than the thicker ones, and that the harder coatings withstood wear significantly better than the steel reference samples thus motivating further investigations
Chapter X: The Tour de France: a success story in spite of competitive imbalance and doping
International audienceThe chapter goes as follows. In the first section it is demonstrated how the Tour de France is a high quality product. This is a result from its accurate design, its management, its economic model and its finance structure, both in comparison to other mega-sporting events and with reference to tournament theory. It is not easy to assess the competitive balance in the Tour de France since, as was demonstrated in chapter 10, it is at the same time an individual and a team sport contest. After reviewing some results published in literature so far, a new metrics for evaluating competitive balanced in the Tour de France is presented in section 2. Finally, the Tour de France cannot ignore doping as a potential threat to fan attendance and TV viewing. We therefore discuss the issue of doping and a new procedure to deal with doping in section 3
Quantitative evaluation of the surface finish of high gloss polished tool steels
Standardized procedures to measure and estimate surface qualities of moulds for injection moulding of plastic components do not exist. Instead, steel producers as well as polishers and mould-users need to rely on master plaques for tactile comparisons and/or their own visual estimations for surface quality controls. This paper presents an overview of various surface evaluation methods of steels, including existing standards and available surface metrology. A new method to evaluate high gloss polished tool steel surfaces, based on a three-dimensional non-contacting measurement technique, is presented. The suggested method is based on defect extraction, and should be useful for both specifications and quality controls. Included defects were found to be quality criteria for polished tool steel surfaces. The surface acceptance levels and defect classification are based on interviews and questionnaires, as well as literature studies and visual estimations of test samples made by experienced polishers. © 2014 IOP Publishing Ltd.</p
Polished injection moulds' and surface defects' influence on the quality of plastic components
Abstract The quality of injection mould surfaces is important as it has a major influence on tool performance. In the specific field of plastic moulding, many products require nearly defect free, glossy, and very smooth mould surfaces [1] (roughness parameters in the nm-range) to achieve a satisfactory surface appearance. The surface quality is also crucial for the mould to function properly in the actual tooling application; too rough surfaces might disturb the flow of the polymer melt and increase wear, while too smooth surfaces give rise to sticking problems. However, there is still a lack of knowledge concerning how different defect structures on mould surfaces affect final plastic components, and how tool steel surfaces can be measured and analysed in convenient ways. This paper summarises a study based on a non-contact 3D-surface texture analysis, where tool steel moulds and injection moulded plastic components are characterised in terms of surface quality (se
On communicating extruded aluminium surface quality along the supply chain – a customer approach to sustainable surfaces
Abstract
Today, far too many products are scrapped due to surface related issues, products with perfect function but with minor surface blemishes. The complaints are often offset by goodwill commitments from suppliers at great cost to them and delivery delays and lead time costs for customers. The reason is that the industry relies on several non-standardized classification systems for surface quality that are based on various combinations of and designations for surface defects, assessed by visual inspections at a defined distance to determine the severity of any detected surface deviations. These similar classification systems provide far too much scope for subjective and non-repeatable assessments causing communication problems between customer and producer at all stages in the supply chain. To challenge this situation, a common toolbox to communicate, describe and define surface quality should be developed, i.e. a standardisation of surface quality assessment including various effects and defects with a jointly established nomenclature and evaluation parameters. This work presents the first step of a research project bringing together 11 suppliers and OEMs along the supply chain, from the delivery of raw aluminium to finished alumina profiles included in consumer products. The final goal of the project is to develop an ‘objective classification of visual requirements’ on alumina profiles towards increased sustainability and decreased material wastage. Presented result is a common terminology with links to the process chain, surface defect geometry and visual appearance aiming at making the communication between producers and buyers of the aluminium profiles clearer and more unambiguous when it comes to specification and requirements of profile surfaces in each of the supply-chain links. Future work will add measurable parameters specifying surface quality.</jats:p
On communicating extruded aluminium surface quality along the supply chain – a customer approach to sustainable surfaces
Today, far too many products are scrapped due to surface related issues, products with perfect function but with minor surface blemishes. The complaints are often offset by goodwill commitments from suppliers at great cost to them and delivery delays and lead time costs for customers. The reason is that the industry relies on several non-standardized classification systems for surface quality that are based on various combinations of and designations for surface defects, assessed by visual inspections at a defined distance to determine the severity of any detected surface deviations. These similar classification systems provide far too much scope for subjective and non-repeatable assessments causing communication problems between customer and producer at all stages in the supply chain. To challenge this situation, a common toolbox to communicate, describe and define surface quality should be developed, i.e. a standardisation of surface quality assessment including various effects and defects with a jointly established nomenclature and evaluation parameters. This work presents the first step of a research project bringing together 11 suppliers and OEMs along the supply chain, from the delivery of raw aluminium to finished alumina profiles included in consumer products. The final goal of the project is to develop an ‘objective classification of visual requirements’ on alumina profiles towards increased sustainability and decreased material wastage. Presented result is a common terminology with links to the process chain, surface defect geometry and visual appearance aiming at making the communication between producers and buyers of the aluminium profiles clearer and more unambiguous when it comes to specification and requirements of profile surfaces in each of the supply-chain links. Future work will add measurable parameters specifying surface quality.</p
