Sustainability improvement of a composite materials' industry through recycling re-engineering process approaches

This case study was aimed at measuring and assessing the potential improvements that couldbe made on the eco-efficiency performance of a composite materials' industry, specifically aglass fibre reinforced plastic (GFRP) pultrusion manufacturing company. For this purpose, allthe issues involved in the pultrusion process of GFRP profiles were analysed, the current ecoefficiency performance of the company was determined, all the procedures applied in theproduction process were revised, and improvement strategies were planned and investigatedwith basis on the performed analysis. The new eco-efficiency ratios were estimated takinginto account the implementation of new proceedings and procedures through re-engineeringthe manufacturing process and recycling approaches. These features lead to significantimprovements on the sequent assessed eco-efficiency ratios, yielding to a more sustainableproduct and manufacturing process of pultruded GFRP profiles

An integrated recycling approach for GFRP pultrusion wastes: recycling and reuse assessment into new composite materials using Fuzzy Boolean Nets

In this study, efforts were made in order to put forward an integrated recycling approach for the thermoset based glass fibre reinforced polymer (GPRP) rejects derived from the pultrusion manufacturing industry. Both the recycling process and the development of a new cost-effective end-use application for the recyclates were considered. For this purpose, i) among the several available recycling techniques for thermoset based composite materials, the most suitable one for the envisaged application was selected (mechanical recycling); and ii) an experimental work was carried out in order to assess the added-value of the obtained recyclates as aggregates and reinforcement replacements into concrete-polymer composite materials. Potential recycling solution was assessed by mechanical behaviour of resultant GFRP waste modified concrete-polymer composites with regard to unmodified materials. In the mix design process of the new GFRP waste based composite material, the recyclate content and size grade, and the effect of the incorporation of an adhesion promoter were considered as material factors and systematically tested between reasonable ranges. The optimization process of the modified formulations was supported by the Fuzzy Boolean Nets methodology, which allowed finding the best balance between material parameters that maximizes both flexural and compressive strengths of final composite. Comparing to related end-use applications of GFRP wastes in cementitious based concrete materials, the proposed solution overcome some of the problems found, namely the possible incompatibilities arisen from alkalis-silica reaction and the decrease in the mechanical properties due to high water-cement ratio required to achieve the desirable workability. Obtained results were very promising towards a global cost-effective waste management solution for GFRP industrial wastes and end-of-life products that will lead to a more sustainable composite materials industry

On the recyclability of glass fiber reinforced thermoset polymeric composites towards the sustainability of polymers' industry

Considering the added value of recycling solution assessed by an evaluation of flexural and compressive loadingcapacity of PC specimens modified with mechanically recycled GFRP wastes, as well as the inherent environmentaland economic benefits, the incorporation of GFRP recyclates into PC materials has been revealed as a viabletechnological option for the sustainability of the GFRP polymers' industry. Nevertheless, the recyclability of compositematerials is complex and is sometimes seen as a key barrier to the adoption of these materials in some markets.One of the few successful applications, was developed by Reprocover, in Belgium, and it has been commercializedsince 2011. In addition, the recently investigation line that was started and concerning the GFRP recyclates into PCmaterials also called the attention of Global Fiberglass SolutionsTM group. Even so, and although all the efforts thathad been done on developing cost-effective recycling routes, GFRP wastes still remain mired by the scarcenessof reliable outlet markets for the recyclates and clearly developed recycling paths between waste producers andpotential consumers for the recyclates. However, it is foreseen that this scenario will change in the next few yearsas strong investments are being made in this field. The innovation in this field has just started, providing as this waya source of new opportunities

Metodologias interdisciplinares em estudos de geoconservação de património geológico-mineiro : o caso da antiga mina de volfrâmio das Aveleiras (Mire de Tibães) : the case of ancient Aveleiras wolfram mine (Mire de Tibães)

This work emphasizes the importance of recovery processes of abandoned mining heritage, as an example of the transformative process of an organization towards a second life cycle. This perspective reflects an important measure for sustainability, either for the organization and the surrounding environment. The Aveleira Mine is an old wolfram mine, belonging to the Monastery of St Martin of Tibães, near Braga, in the North of Portugal. It was the mother house of the Benedictine order in Portugal. By the initiative of the Tibães Monastery this mine will probably reconverted, partially, in a geosite and, probably, near future in mining museum. The work aim was to present a methodological approach, in a geoconservation point of view, allowing an ulterior partially recovering and stabilization of the Aveleiras ancient mine

Finite Element Analysis (FEA) applied to heat transfer optimization process of pultrusion die systems

The aim of this study is to optimize the heat flow through the pultrusion die assembly system on the manufacturing process of a specific glass-fiber reinforced polymer (GFRP) pultrusion profile. The control of heat flow and its distribution through whole die assembly system is of vital importance in optimizing the actual GFRP pultrusion process. Through mathematical modeling of heating-die process, by means of Finite Element Analysis (FEA) program, an optimum heater selection, die position and temperature control was achieved. The thermal environment within the die was critically modeled relative not only to the applied heat sources, but also to the conductive and convective losses, as well as the thermal contribution arising from the exothermic reaction of resin matrix as it cures or polymerizes from the liquid to solid condition. Numerical simulation was validated with basis on thermographic measurements carried out on key points along the die during pultrusion process

Effects of prescribed fire on surface soil in a Pinus pinaster plantation, northern Portugal

In order to decrease the risk of severe wildfire, prescribed fire has recently been adopted in Portugal and elsewhere in the Mediterranean as a major tool for reducing the fuel load instead of manual or mechanical removal of vegetation. There has been some research into its impact on soils in shrublands and grasslands, but to date little research has been conducted in forested areas in the region. As a result, the impact of prescribed fire on the physico-chemical soil characteristics of forest soils has been assumed to be minimal, but this has not been demonstrated. In this study, we present the results of a monitoring campaign of a detailed pre- and post-prescribed fire assessment of soil properties in a long-unburnt P. pinaster plantation, NW Portugal. The soil characteristics examined were pH, total porosity, bulk density, moisture content, organic matter content and litter/ash quantity. The results show that there was no significant impact on the measured soil properties, the only effect being confined to minor changes in the upper 1 cm of soil. We conclude that provided the fire is carried out according to strict guidelines in P. pinaster forest, a minimal impact on soil properties can be expected