Carlos Javierre

Study of the biodisintegration of a bioplastic material waste

The aim of this work was to study the biodisintegration degree of different pieces made of a biodegradable thermoplastic material, the polylactic acid (PLA) with and without corn in its composition, is studied. The pieces of different shapes and thicknesses were obtained by both injection and extrusion processes, where also a specific foaming additive of polystyrene was added. The PLA and PLA-corn manufactured pieces were subjected to aerobic degradation at a constant temperature of 58+/-2 degrees C for 90 days, following EN 14806 and ISO 20200:2004 Norms. It was found that the pieces made of PLA and PLA with foaming agent had an average biodisintegration degree of 63.6%. With regard to the pieces made of PLA-corn, an average biodisintegration degree of 79.7% was obtained. In this case, the percentage of non degraded material was independent of the size, shape and thickness of the original pieces.

Influence of mechanical design on the evolution of the environmental impact of an induction hob

PurposeThis paper studies the influence of the mechanical design of five different induction hob generations (G1 to G5), which are currently installed in several million homes, on the evolution of their environmental impact.MethodsLife cycle assessment (LCA) has been applied using SimaPro 8.0.3.14 and EcoInvent v2.2 database. Samples of each design were obtained to generate a life cycle inventory. These induction hobs have been developed and produced in Zaragoza (Spain). The functional unit has been defined as all of the components influenced by the mechanical design of a cooktop with four induction hobs and a width of 60xa0cm, including every component except the electronic boards and the use phase, as they are not affected by the mechanical design. The limits of the LCA model include the production of the raw materials and energy, the manufacture and production processes, the distribution, and the end of life.Results and discussionThis study has revealed that the differences in mechanical design highly affect the environmental impact, especially in the environmental categories of abiotic depletion and human toxicity due to the consumption of copper, steel, and plastics. The manufacturing phase highly affects human toxicity, mainly due to the variation in PPS use. There is a decreasing tendency in the environmental impact from the first (G1) to the last generation (G5), as G5 causes the lowest burden in 8 out of 11 analysed categories. The different generations analysed in this paper show that the compact designs of induction hobs help to decrease the environmental impact, especially thanks to the reduction in wiring lengths. It is also important to enhance the wiring separation at the end-of-life phase, avoiding designs that hinder recycling processes.ConclusionsCompact designs and reduced wiring lengths help to reduce the environmental impact. The consumption of copper, steel, aluminium, and polymers creates considerable impact, although the end-of-life phase reduces the burden created by metals, thanks to recycling. Manufacturing processes such as injection moulding also produce a noteworthy impact, especially in ozone layer depletion due to the inclusion of solvents in EcoInvent’s injection moulding dataset. The impact caused by the distribution phase for this product is almost negligible in most categories.

Methodology in gas assisted moulding of plastics

Abstract During the last years, gas assisted injection moulding has been implanted in lots of applications [1] , [5] , which are usually quite different between them. The quality is highly improved for lots of parts, and so, many manufacturers think of this process to solve any kind of problem. In order to be able to apply a gas technique to a part, this one must have some characteristics that make it susceptible of applying gas assisted injection moulding, and obtain satisfactory results. According to TIIP experience, [3] , [4] gas assisted processes can be usually divided into three different techniques: conventional gas assisted technique, rib emptiness technique without overflow pipes, and rib emptiness technique with overflow pipes. In this paper, an overview on these three techniques will be done, taking into account the kind of parts on which each technique should be applied, and showing their advantages and disadvantages. The TIIP, where this study has taken place, has a great knowledge on plastics and its transformation, and it owns a great infrastructure that has allowed them to carry out all the stages of this study: at the first stage, a theoretical analysis by using the CAD–CAE software C-MOLD [2] , and at the second stage, testing and stating exactly the results previously obtained, in its test laboratory.

The Influence of Different Recycling Scenarios on the Mechanical Design of an LED Weatherproof Light Fitting

This paper analyzes the high relevance of material selection for the sustainable development of an LED weatherproof light fitting. The research reveals how this choice modifies current and future end of life scenarios and can reduce the overall environmental impact. This life cycle assessment has been carried out with Ecotool, a software program especially developed for designers to assess the environmental performance of their designs at the same time that they are working on them. Results show that special attention can be put on the recycling and reusing of the product from the initial stages of development.

Environmentally Conscious Polishing System Based on Robotics and Artificial Vision

Polishing process is one of the manufacturing issues that are essential in the production flow, but it generates the major amount of defects on parts. Finishing tasks in which polishing is included are performed in the final steps of the manufacturing sequence. Any defect in these steps impliesrejection of the part, generating a big amount of scrap and generating a huge amount of energy consumption, emission, and time to manufacture and replace the rejected part. Traditionally polishing process has not evolved during the last 30 years, while other manufacturing processes have been automated and technologically improved. Finishing processes (grinding and polishing), are still manually performed, especially in freeform surface parts, but to be sustainable some development and automation have to be introduced. This research proposes a novel polishing system based on robotics and artificial vision. The application of this novel system has allowed reducing the failed parts due to finishing process down to zero percent from 28% of rejected parts with manual polishing process. The reduction in process time consumption, and amount of scrapped parts, has reduced the energy consumption up to 30% in finishing process and 20% in whole manufacturing process for an injection moulded aluminium part for automotive industry with high production volumes.

Influence of composition on the environmental impact of a cast aluminum alloy

The influence of alloy composition on the environmental impact of the production of six aluminum casting alloys (Al Si12Cu1(Fe), Al Si5Mg, Al Si9Cu3Zn3Fe, Al Si10Mg(Fe), Al Si9Cu3(Fe)(Zn) and Al Si9) has been analyzed. In order to perform a more precise environmental impact calculation, Life Cycle Assessment (LCA) with ReCiPe Endpoint methodology has been used, with the EcoInvent v3 AlMg3 aluminum alloy dataset as a reference. This dataset has been updated with the material composition ranges of the mentioned alloys. The balanced, maximum and minimum environmental impact values have been obtained. In general, the overall impact of the studied aluminum alloys varies from 5.98 × 10−1 pts to 1.09 pts per kg, depending on the alloy composition. In the analysis of maximum and minimum environmental impact, the alloy that has the highest uncertainty is AlSi9Cu3(Fe)(Zn), with a range of ±9%. The elements that contribute the most to increase its impact are Copper and Tin. The environmental impact of a specific case, an LED luminaire housing made out of an Al Si12Cu1(Fe) cast alloy, has been studied, showing the importance of considering the composition. Significant differences with the standard datasets that are currently available in EcoInvent v3 have been found.

A systematic material selection process applied to a luminaire diffuser

This paper presents a systematic material selection process for technical, environmental and economic criteria. This methodology has been applied to the design of a weatherproof luminaire. The materials selected for the production of this diffuser were characterised to obtain their mechanical properties and to perform exhaustive research on impact analysis by means of finite element modelling. Also an economic analysis and an ecological impact assessment have been performed. Thanks to this working methodology, a final design of the diffuser has been developed having the optimum thickness to achieve the mechanical specifications and minimise the environmental impact and the cost of the diffuser.

Surface Roughness Evolution Model for Finishing Using an Abrasive Tool on a Robot

The polishing process is the final step in the manufacturing workflow for many parts and tools. While previous tasks have evolved technically, the finishing of freeform surfaces is still effected mostly by hand. Many parts are rejected because no control of the process is possible. The main problems are geometrical shape deviations and no repeatability of the process. A new methodology has been developed for the passes of the abrasive on the polished part. This research focusses on the feasibility of robotic polishing and the development of a new evolution model pertaining to the surface roughness for an abrasive tool mounted on a spherical robot. The polishing principle is mechanic and based on dry friction. The tool is multilayered with a compressive foamed core. The combination of rotational and translational movement requires the creation of a model that can predict the footprint on the polished surface. The mathematical model developed for the evolution model permits for making a prediction of the final surface quality in the function of the programmed polishing parameters. Furthermore, the model described allows for setting up polishing parameters in order to reach a desired final roughness with less than 15% deviation. Repeatability is assured and polishing time is reduced down to 1/5 of manually effected procedures.

Analysis of the Influence of Microcellular Injection Molding on the Environmental Impact of an Industrial Component

Microcellular injection molding is a process that offers numerous benefits due to the internal structure generated; thus, many applications are currently being developed in different fields, especially home appliances. In spite of the advantages, when changing the manufacturing process from conventional to microcellular injection molding, it is necessary to analyze its new mechanical properties and the environmental impact of the component. This paper presents a deep study of the environmental behavior of a manufactured component by both conventional and microcellular injection molding. Environmental impact will be evaluated performing a life cycle assessment. Functionality of the component will be also evaluated with samples obtained from manufactured components, to make sure that the mechanical requirements are fulfilled when using microcellular injection molding. For this purpose a special device has been developed to measure the flexural modulus. With a 16% weight reduction, the variation of flexural properties in the microcellular injected components is only 6.8%. Although the energy consumption of the microcellular injection process slightly increases, there is an overall reduction of the environmental burden of 14.9% in ReCiPe and 15% in carbon footprint. Therefore, MuCell technology can be considered as a green manufacturing technology for components working mainly under flexural load.

Conformal polishing approach: Tool footprint analysis

Polishing process is one of the most critical manufacturing processes during a metal part production because it determines the final quality of the product. Free-form surface polishing is a handmade process with lots of rejected parts, scrap generation and time and energy consumption. Two different research lines are being developed: prediction models of the final surface quality parameters and an analysis of the amount of material removed depending on the polishing parameters to predict the tool footprint during the polishing task. This research lays the foundations for a future automatic conformal polishing system. It is based on rotational and translational tool with dry abrasive in the front mounted at the end of a robot. A tool to part concept is used, useful for large or heavy workpieces. Results are applied on different curved parts typically used in tooling industry, aeronautics or automotive. A mathematical model has been developed to predict the amount of material removed in function of polishing parameters. Model has been fitted for different abrasives and raw materials. Results have shown deviations under 20% that implies a reliable and controllable process. Smaller amount of material can be removed in controlled areas of a three-dimensional workpiece.