Identification of potential applications for recycled polymeric multi-material

Abstract

This research aims to characterise a recycled polymeric multi-material, explore potential areas of application for it and analyse the eventual impacts of the introduction of this new recycled material (NRM) on end-of-life activities. Thus, this research presents a practical study regarding recycled polymeric multi-material from toothbrushes. A preliminary characterisation (via density determination, tensile test and dynamic mechanical thermal analysis – DMTA) and data analysis using the Cambridge Engineering Selector (CES-Edupack 2013) software have been done. The study also presents an analysis of the impacts of introducing the NRM into end-of-life activities. Results shows that, based on the properties considered in this study, NRM may have potential for new applications. The impact on recycling networks indicates that it is a positive solution that would improve process variable efficiencies, maintaining material value as long as possible in industrial closed-loop life cycles. However, an in loco analysis of the treatment of waste containing the NRM is necessary.

Keywords:

• Polymeric multi-materials
• recycling
• potential of application
• materials properties charts
• recycling networks

1. Introduction

The trend of using more than one material in the same product component has been noticed (Kromm et al. 2007; Thomas and Weimin 2009). Multi-material products emerge primarily of two main factors: the development of polymeric materials and increasing demand of polymers in substitution of other materials, due to its low price, ease of processing and versatility (Thomas and Weimin 2009; Wargnier et al. 2014). Multi-material products present several technical and manufacturing advantages: reduced time and cost of production, decrease of manual labour, more functions and properties on a single component and less bulky parts (Advani and Hsaio 2012; Wargnier et al. 2014). Besides, only one mould and one injection equipment are needed to produce economically a product in a single step (Boothroyd, Dewhurst, and Knight 2011).

It is expected that more multi-material products will be developed in the near future and the end-of-life options for these mixed materials must be discussed. According to the literature (Koushal et al. 2014; Kreiger et al. 2014; Nkwachukwu et al. 2013; Rajendran et al. 2012), the best way to manage polymeric solid waste is by recycling. The recycling of multi-material products is already being studied (Ashton et al. 2016) and some results show that reprocessing materials of different melting points is a challenge regarding homogeneity and interfacial adhesion, since different processing temperatures may generate distinct morphologies. Despite the recognised difficulties involving reprocessing of multi-material products, the hypothesis of the present study is that even a new material with lower interfacial adhesion may have a proper new application that suits its properties. That is why the reprocessing itself solves only one part of the problem. Since recycled mixed polymers present unknown properties and tends to lose performance after recycled cycles (Lorenzo et al. 2014; Moeller 2008), the introduction of these materials in new production networks is difficult. Thus, the search for uses of a recycled multi-material is important to expand the recycling networks and minimise solid waste generation. Studies have been conducted focusing on materials selection for the development of environmental-friendly products (Almeida et al. 2010; Prendeville, O’Connor, and Palmer 2014). However, only few studies search for potential applications for a recovered or recycled material.

A study on the circularity of global material flows, (Haas et al. 2015) shows that only 6% of all materials processed by the global economy are recycled and contribute to closing the loop. In order to create an effective after-use plastics economy, the New Plastics Economy report (Ellen MacArthur Foundation 2016) proposes to radically increase the economics, quality and uptake of recycling by:

• Establishing a cross-value chain dialogue that could favour the convergence of materials, formats and after-use systems to improve collection, sorting and reprocessing yields, quality and economics;

• Enabling secondary markets for recycled materials through the introduction and scale-up of matchmaking mechanisms and industry commitments;

• Focusing on key innovation opportunities such as new or improved materials and reprocessing technologies;

• Exploring the overall enabling role of policy interventions (Ellen MacArthur Foundation 2016).

Thus, this research aims to assess potential areas of applications for a new recycled material (NRM), by building and interpreting materials properties charts (MPC) with a novel approach, and to analyse the potential impacts of the introduction of it to end-of-life activities.

2. Material and methods

2.1. Material

The material (NRM) was obtained from recycled co-injected toothbrushes. This NMR composition was 30 wt% of direct recycled toothbrushes (polypropylene – PP, polyamide – PA and ethylene-propylene-diene monomer – EPDM) and 70 wt% virgin linear low-density polyethylene (LLDPE).

2.2. Samples preparation

Samples for testing were prepared in a Haake Minijet II injection moulding equipment, according to ASTM D638 (2014), specimen-type V. The parameters used are presented in Table 1. Before injection moulding, the NRM was dried in a hot air oven at 80 °C for 3 h.

Table 1. Injection moulding parameters.

Melting temperature	200 °C
Mould Temperature	30 °C
Injection pressure/post pressure	300/280 bar
Injection time	8s

2.3. Density test

The density was determined by displacement, according to ASTM D792 (2013), Test Method B. The liquid used was ethyl alcohol.

2.4. Tensile test

Tensile properties were carried out in a Shimadzu EZ-LX, with Trapezium X software at speed of 100 mm/min, according to ASTM D638 (2014).

2.5. Dynamic mechanical thermal analysis (DMTA)

DMTA analysis was performed in single cantilever mode, using specimens with approximate dimensions of 30 × 3.2 × 12.75 mm in a Perkin Elmer Q8000 equipment, at a fixed frequency of 1 Hz. The samples were heated between 22 °C and 100 °C at a heating rate of 2 °C/min.

2.6. Cambridge Engineering Selector (CES-Edupack)

CES software (CES-Edupack 2013) was used to compare the characterised NRM’s data with a universe of more than 3900 materials through a sequence of MPC shown in Table 2. Instead of the regular materials selection approach, which uses a reference material in successive steps to screen a database for ‘equal or better’ materials candidates for a given application, it is proposed the opposite way, i.e. to search for possible applications for a given material. In this ‘equal or worse’ approach, a list of selected materials with similar or lower performance (expressed in merit indexes) than the NRM is given. This means that those listed materials maybe, hypothetically, substituted by the NRM. Thus, the typical uses of those selected ‘equal or worse’ candidates are then evaluated as possible market that have to be prospected to find a use for the NRM.

Table 2. Property charts structure.

Chart	Y axis	X axis
1	Yield Strength	Density
2	Young’s Modulus	Density
3	Young’s Modulus	Yield Strength
4	Yield Strength	Elongation
5	Tan delta	Young’s Modulus

A definitive application selection for a newly introduced material requires a complete characterisation process, which may include a broad set of properties (mechanical, chemical, thermal, optical and so on). It is known that those analyses depend on equipment, time and financial resources usually not available neither for recycling companies or research projects. The proposed approach allows insight on a preliminary evaluation based on basic properties of the new material and in the common uses of the ‘equal or worse’ selected concurrent materials. Thus, in a second stage, the characterisation effort can be focused on specific sector’s standards in a more effective manner. It means that first it is necessary to evaluate potential areas of application for a new material from a large universe of options, which involves basic and general testing. Once these potential applications are known, specific characterisation testing maybe made according to the applications’ requirements and sector’s standards. In this study, the first stage is addressed, relative to basic and general testing to find preliminary areas of application.

2.7. Analysis of recycling networks

The characterisation of polymer recycling networks that was conducted in this study was based on a holistic PESTEL-inspired analysis of polymer recycling activities similar to the approach undertaken by (Ziout, Azab, and Atwan 2014), in which political, economic, social, technical, environmental and legal aspects were studied in order to find relevant factors that describe these networks (descriptors). This approach relies on empiric and historical data from the industry, as well as a review of the scientific literature on the subject. Three types of references were studied: scientific research on recycling processes, industrial expert reports and sectorial reviews. The critical review focused on what was put forth as a modifier of the use of scrap material in new product cycles. In order to confront the results with the reality of the field, different experts from companies dealing with plastic recycling activities were interviewed to comment and complete the results issued from the literature review. Thus, new factors for the polymer cycling networks were identified and the compatibility of the academic and industrial concerns was established for many of these factors. Plastic materials were considered as a single industrial network (which is compatible with how they are commonly assessed in sectorial reports) due to the shortage of consistent data for individual polymer networks. Table 3 shows the descriptors that were gathered from this assessment. The descriptors were grouped in three categories based on the types of variables involved: process, market and the general environment conditions of the waste management network. Two sub-categories of process variables were distinguished: one pertaining to the process’ technical optimisation and another relating to product design issues affecting cycling operations. Market variables were divided between macro-economic and micro-economic parameters affecting recyclers. The environment conditions encompassed organisational, regulatory and social factors.

Table 3. Factors that characterise polymer recycling networks.

Categories	Subcategories	Descriptors	Validation	References
Process variables	Technical optimisation	Separation efficiency	Lit. and indust. expertise	Welle (2011), Patel et al. (2000), Soroudi and Jakubowicz (2013)
		Treatment efficiency	Lit. and indust. expertise	Hamad, Kaseem, and Deri (2013), Patel et al. (2000), Shen and Worrell (2014), Soroudi and Jakubowicz (2013), Welle (2011)
		Secondary material properties	Lit. and indust. expert	Howell (1992), Haeusler and Pellan (2012), Soroudi and Jakubowicz (2013), Hamad, Kaseem, and Deri (2013), Shen and Worrell (2014), Sadat-Shojai and Bakhshandeh (2011), Patel et al. (2000), Hopewell, Dvorak, and Kosior (2009)
	Product design	Material mixes	Lit. and indust. expertise	Welle (2011), Patel et al. (2000), Shen and Worrell (2014), Hopewell, Dvorak, and Kosior (2009)
		Material concentration in component	Literature	Welle (2011)
Market variables	Macro	Global material demand prediction	Industrial expertise	–
		Material accumulation in use	Industrial expertise	–
		Price of virgin raw materials	Lit. and indust. expertise	Haeusler and Pellan (2012), Patel et al. (2000), Hopewell, Dvorak, and Kosior (2009)
		Price of secondary raw materials	Industrial expertise	–
		Size of waste deposit	Lit. and indust. expertise	Patel et al. (2000), Soroudi and Jakubowicz (2013), Welle (2011)
		Quality of waste deposit	Lit. and indust. expertise	Shen and Worrell (2014)
	Micro	Transportation costs	Lit. and indust. expertise	Patel et al. (2000)
		Labour costs	Industrial expertise	–
		Downstream secondary material applications	Lit. and indust. expertise	Welle (2011), Hopewell, Dvorak, and Kosior (2009)
Environment conditions	End-of-life network configuration	Collection mechanisms	Lit. and indust. expertise	Soroudi and Jakubowicz (2013), Welle (2011), Shen and Worrell (2014), Al-Salem, Lettieri, and Baeyens (2010), Hopewell, Dvorak, and Kosior (2009)
		Waste management development level	Lit. and indust. expertise	Hopewell, Dvorak, and Kosior (2009)
	Regulatory framework	Environmental regulations	Industrial expertise	–
		Raw material policies and economic incentives	Industrial expertise	–
	Social involvement	Consumers	Lit. and indust. expertise	Welle (2011)
		Manufacturers	Lit. and indust. expertise	Welle (2011), Hopewell, Dvorak, and Kosior (2009)

3. Results and discussion

3.1. Characterisation of the NRM and MPC analysis

The results obtained in the characterisation of the NRM are presented in Table 4.

Table 4. Characterisation results.

Property	Unit	Average
Density	kg/m³	898.1 ± 0.068
Yield Strength	MPa	20.92 ± 0.51
Ultimate Strength	MPa	21.33 ± 0.82
Elongation at Break	%	153 ± 36.3
Young’s Modulus	GPa	0.729 ± 0.03
Tan delta	–	0.106 ± 0.006

The density determination showed that the density of the studied material is approximately 898.1 kg/m³, slightly lower than the virgin LLDPE (the matrix of the blend, representing 70 wt% of the mixture) that present density of 937 kg/m³, according to the data sheet of the material provided by the manufacturer. This was expected, since PP and EPDM present approximately 899 kg/m³ for PP, and 860 kg/m³ for EPDM (CES-Edupack 2013).

Through DMTA analysis, it was possible to obtain the tan delta at 30 °C, which is 0.106. This information was necessary to build the material properties chart 5 (Tan delta against Young’s Modulus). The selected charts are presented in Figures 1–5.

Figure 1. Materials properties chart 1 (Yield strength against Density).

Figure 2. Materials properties chart 2 (Young’s Modulus against Density).

Figure 3. Materials properties chart 3 (Young’s Modulus against Yield Strength).

Figure 4. Materials properties chart 4 (Yield Strength against Elongation).

Figure 5. Materials properties chart 5 (Tan delta against Young’s Modulus).

The Yield Strength (σ _y) against Density (ρ) chart is regularly used to screen for lighter materials for a given load application, i.e. to find materials that will support the same stress without failure (permanent deformation) and a reduced mass for a component; or to find materials that result in similar mass components with increased stress resistance.

Young’s Modulus (E) against Density (ρ) chart gives mass reduction for components with deformation constrains, i.e. indicating the stiffness of materials.

Young’s Modulus (E) against Yield Strength (σ _y) chart allows the simultaneous comparison of those two mechanical properties.

Yield Strength (σ _y) against Elongation (ε) chart is used as ductility reference, searching for materials that absorb similar amounts of energy while deforming until its rupture.

Tan delta against Young’s Modulus (E) chart gives guide for damping materials, i.e. those who absorb noise and vibration. After building all MPC, 71 materials that pass all selection stages were listed. Among them, there is a significant amount of polymers and elastomers. Also, there are some foams, natural materials and non-technical ceramics.

The selection process starts from a large universe to reach a selected range of final options, so the materials which application is considered not suitable for the NRM have to be excluded. In this sense, each of the chart’s remaining materials were analysed and submitted through a new screening. Here, those materials whose application mainly depends on some characteristics not tested in this research were excluded. As an example there are the thermoset elastomers (rubbers), since most of them have applications related to chemical resistance (CES-Edupack 2013), a property that was not evaluated in this study. Other materials dismissed in this stage were the non-technical ceramics, due to their high-service temperature and ultraviolet (UV) resistance, which are requirements for their main applications, e.g. finishing for roofs, walls and floors and applications for fire resistance (CES-Edupack 2013; Somiya 2013). In addition to these properties that were not concerned in this study, it is known that most polymers do not support high temperatures. Materials with properties related to macro-structures, such as foams were also discarded.

After this filtering, a more restricted set of three materials that draw attention for being similarly close to the NRM on all charts was obtained, which are: leather, flexible polyvinyl chloride (PVC) and low-density polyethylene (PE-LD). Thus, the first conclusion obtained from the charts results is that the NRM does not exhibit satisfactory performance in structural applications, since the majority of the remaining materials have typically non-structural applications. It is important to highlight that this stage selected candidate materials that may present similar performance to the NRM, regarding only the considered properties.

3.2 Potential applications selection

Among these three remaining materials, the LD-PE was already expected to be one of the most similar the NRM, since it is the main polymer in the mixture (70 wt%) used in the NRM blend. Polyethylene’s typical application areas include containers and bowls, food packaging, bottles, toys. The use of PE-LD in containers and bowls are a quite generic application, which maybe a potential area of application for the NRM. It is important to highlight that recycled polymeric materials are an important source of additives. After recycling, the additives they contain, such as flame retardants and plasticisers, are transferred to the newly manufactured goods; therefore, their use in products for children, like toys, should be subjected to stricter restrictions (Lonas et al. 2014). This should also be noticed in the use of polymeric materials in bottles for drinking water and articles intended to come into contact with food. The use of polymeric materials in this sort of applications is also controversial when regarding toxicology (Bach et al. 2012). LD-PE is also widely used in the manufacture of cable coverings (CES-Edupack 2013). This application is also typically assigned to the flexible PVC (CES-Edupack 2013), which also appeared near the NRM on all charts, which may indicate a potential application for the NRM. However, it should be noted that this use requires electrical insulation and fire testing that should be considered in a second stage of selecting applications.

Two of the final set materials (leather and flexible PVC) among many others are traditionally used in the same application area – shoe components, which points out another preliminary potential area of application for the NRM. Leather is a natural material, its main applications include: belts, bags, shoes, clothes, coats and linings. These options are associated with leather mainly due to its resilience and resistance (Ashby and Johnson 2014). As an alternative to leather, there is the flexible PVC (CES -Edupack2013; Cheng et al. 2015). The main characteristics presented by flexible PVC, used in shoes, are the low cost and processability (Andrade and Corrêa 2001). However, flexible PVC products present environmental and health risks, which restricts its use to determined limits of air pollutants emitted during its production (Konar, Gu, and Sain 2013; Pacheco-Torgal, Jalali, and Fucic 2012). In this aspect, the NRM could present an advantage against flexible PVC. However, regarding the flexibility of the flexible PVC, Figure 3 (Young’s Modulus against Yield Strength) shows that the NRM presents less flexibility than PVC and leather. So, it is expected that the final component (hypothetically) made from NRM would be more rigid than the one made by PVC and the leather, which may drive the application options of the NRM, i.e. instead of applying it on the shoes whole upper part, it could be used in some details or specific parts of the top. To confirm this application option, it would be necessary to test it directly on the product.

Thus, considering the potential areas of application evaluated in this study, cable coverings, containers/bowls and shoe components maybe potential areas of application for the NRM. To ensure that these potential uses are viable in practice, a real application and evaluation would be necessary, it is the suggestion for future studies. It is also highlighted that this study presented a methodology for selecting applications for new recycled mixed materials, that maybe reproduced for other materials. Thus, the steps to follow are summarised next, which should be applied in further studies to validate this methodology:

(a)	Characterisation of the NRM;
(b)	MPC construction;
(c)	Inclusion of the NRM on the MPC;
(d)	MPC analysis based on similarity by the ‘equal or worse’ approach;
(e)	Elimination analysis of the main applications of the materials close to NRM in the charts;
(f)	Viability test of the remaining potential areas of application.

As described previously, the results regarding the applications for the NRM should be verified in practice, with a real application and evaluation, but anyway it is possible to make an overview about impact on recycling networks.

3.3 Analysis of the NRM impact on recycling networks

Although it prevents some issues from the end-of-life treatment of a multi-material product, the production of a NRM may affect the recycling network that will handle it at the end of its life cycle. Introducing a new material can disturb the fragile balance that ensures the cost effectiveness of a recycling activity and may require the creation of new processes to be implemented, potentially harming the overall recovery rate of the materials over multiple life cycles.

The introduction of the NRM as an alternative outflow for polymer recycling networks has implications on the life cycles that precede and follow it (Figure 6). The evaluation of the impacts of the NRM on the recycling networks was therefore carried out for the two successive end-of-life scenarios: the first evaluation when the NRM is produced and the second evaluation when the NRM is treated. The assessment was performed in qualitative terms based on the issues regarding polymer recycling (for end of life 1) and multi-material polymer recycling (end of life 2) identified in the literature review provided in Table 3. It is presented in Table 5.

Figure 6. Position of the NRM in a multiple life cycle perspective.

Table 5. Impact assessment of the introduction of the NRM on polymer recycling networks.

			Impact
Categories	Subcategories	Descriptors	End of life 1	End of life 2
Process variables	Technical optimisation	Separation efficiency	++	+
		Treatment efficiency	++	−
		Secondary material properties	+	−
	Product design	Material mixes	++	+
		Material concentration in component	0	+
Market variables	Macro	Global material demand prediction	0	0
		Material accumulation in use	0	−
		Price of virgin raw materials	0	0
		Price of secondary raw materials	0	0
		Size of waste deposit	+	−
		Quality of waste deposit	+	−
	Micro	Transportation costs	0	+
		Labour costs	0	0
		Downstream secondary material applications	+	0
Environment conditions	End-of-life network configuration	Collection mechanisms	0	0
		Waste management development level	0	−
	Regulatory framework	Environmental regulations	0	0
		Raw material policies and economic incentives	0	0
	Social involvement	Consumers	0	0
		Manufacturers	0	+

Notes: Qualitatitve impact scale: ++ for very positive impact; + for positive impact impact; 0 for no impact; − for negative impact.

The evaluation showed that the NRM is globally a good prospect for the treatment of multi-material products as it allows to generally preserve material value as long as possible in an industrial closed-loop life cycle. It has positive effects on most descriptors of the recycling networks. It is especially beneficial for process variables since it simplifies separation and reduces the hindrances due to contamination, thus increasing the efficiency of the treatment. Economically speaking, it can increase the list of materials suitable for recycling of the waste deposit to be treated, concomitantly increasing cost-effectiveness. The multiple potential downstream applications also favour recycling activities. Collection mechanisms are a double-edged issue: while collection can be disencumbered due to higher tolerance to material mixes, adaptation to this new paradigm of multi-material product sorting could be difficult at first.

The impact of the NRM on the recycling networks after it is discarded provides mixed results. Because it is a new material composed of mixed polymers; recyclers may not know how to treat it initially, which would decrease their process yields. Processes are usually optimised for single materials and the NRM may therefore not be considered for recycling. Also, since its lifetime could be longer than that of the first life cycle, its waste deposit will take longer to reach a sufficiently large volume of material that would make a specific network for treating it economically viable However, there are no estimations on the size of the NRM market available yet. Moreover, there would be positive effects on the manufacturer’s stance as it could push for the implementation and development of a recycling network and thus compound the environmental benefits from the adoption of the NRM in its production process.

4. Conclusion

It is known that the best solution for stimulate recycling is the development of products in which materials could be easily separated and reprocessed. Since this is still not a reality, the proposition of this study was to evaluate what are the possibilities for polymeric multi-materials in the end of life. For this reason, this study aimed to characterise, explore potential applications for the NRM and analyse its impact on recycling networks.

The MPC construction through the ‘equal or worse’ proposed methodology allowed the identification of a selected range of materials similar to the NRM, which led to the visualisation of three main potential areas of application for it: cable coverings, containers/bowls and shoe components. It is important to highlight, however, that designers should be aware when specifying recycling materials into new industrial products, because the performance is different between virgin materials and recycled ones. It should be considered, in order to avoid failures that could compromise the project. To prove accurately the viability of using the NRM (multi-materials) in the suggested areas, it is necessary further testing, such as abrasion resistance, chemical resistance, embodied energy. As well as the actual application of the NRM in the suggested products, which lead to the proposal for further research.

It is relevant to enhance that the results here presented, concerning the application areas for the NRM, may not be generalised to all toothbrushes nor all multi-materials, since products from different manufacturers may present a varied composition, which would result in a recycled final material with different morphology and properties. Subsequently, this situation leads to other sorts of applications. This applies to any multi-material product that would be recycled as one unit. In this sense, this article demonstrated that mixed recycled materials may have potential for new proper applications considering its properties and specific characteristics. So, this study proposes a methodology for selecting applications for a NRM. To validate this method, it would be necessary to reproduce this study in other recycled materials which could be proposed in further studies.

Regarding the analysis of the impact that NRM would have as an output of recycling networks, results show that it is a positive solution that would improve process variable efficiencies, thus allowing to maintain material value as long as possible in industrial closed-loop life cycles. However, for actual use, the analysis in loco of the treatment of waste containing the NRM is necessary, because it may be difficult to sort and reprocess and would thus hinder the recycling networks’ overall efficiency.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

This work was supported by the Coordination for the Improvement of Higher Education Personnel – CAPES/Brazil [process BEX 5786/15-0]; the National Council for Scientific and Technological Development – CNPq/Brazil.

Notes on contributors

Elisa Guerra Ashton Elisa Guerra Ashton is professor of multisensory design and sustainability at ESPM (Superior School of Advertising and Marketing), she was also a researcher at LdSM (Design and Material Selection Laboratory), integrated to the Federal University of Rio Grande do Sul. Her main research areas include sustainability, ecodesign, material efficiency and eco-innovations.

Wilson Kindlein Junior is head Professor at Federal University of Rio Grande do Sul (UFRGS). He works at the Department of Materials at UFRGS Engineering School; is professor of the postgraduate programme in design - PGDesign and the graduate programme in Mining, Metallurgy and Materials Engineering. He is also a level 1A researcher productivity scholar of the National Council of Scientific and Technological Development – CNPq. He has coordinated the CNPq’s Industrial Design Adviser Committee in the Technological Capacitation and Competitiveness Program (2013/2016). He was assistant coordinator of CAPES Professional Masters in Architecture, Urbanism and Design areas (2013/2016) and of the Architecture, Urbanism and Design Advisory Committee at FAPERGS (2011/2015). He received from FAPERGS the Highlight Researcher Award 2012 in the area of Architecture, Urbanism and Design. He is Scientific advisor - Ad hoc - of CNPq and CAPES and member of the Latin American Design Honor Committee. Honorary Title Received: Laboratory Prof. WILSON KINDLEIN JÚNIOR - Laboratory of University Center Teresa DAVILLE - Lorena - São Paulo (2010). He was substitute coordinator of the Design Post-Graduate Program (UFRGS/2011-2015), coordinator of the Design Post-Graduate Program (UFRGS/2007-2011) and of the Design and Materials Selections Laboratory (LdSM-UFRGS/1998-2017). He also coordinated the Industrial Assessor-Design Committee/Engineering Coordination/COENG/CNPq (2007/2010). He is Post-Doctor in Industrial Design (France) and PhD in Materials Engineering, with experience in Materials Design and Selection since 1990 with industrial experience.

Yuri Walter is a materials engineer working on product design, with 10+ years experience in consultancy, research and teaching in materials and manufacturing process selection. Currently, professor of product engineering at UFES, Universidade Federal do Espírito Santo.

Mauricio Dwek is graduated in Material Science (USP in Brazil, 2008). MSc in Chemical Engineering (ENSCL in France, 2009) and Production Engineering (UFRJ in Brazil, 2012). Ph.D. in Industrial Engineering (G-SCOP in France, 2017). Main research areas are Circular Economy, Recycling, Ecodesign, STS, Action Research and Engineering Education. Currently works as Communications Manager at MOD Devices (Germany). Member of the editorial board of Revista Docência do Ensino Superior (Brazil). Scientific Advisor for the Arts and Sciences association Anahata (France).

Peggy Zwolinski is professor of engineering design and sustainable engineering at Univ. Grenoble Alpes. She has been head of the G-SCOP laboratory research group on design for environment from 2007 to 2015. She has realised numerous research projects for the industry related to ecodesign. She is currently heading a large research project on sustainable circular industrial systems.