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Alessandra Passaro, Head of Advanced Materials & Processes Consulting Department at CETMA

JEC Composites Magazine speaks to Alessandra Passaro, Head of Advanced Materials & Processes Consulting Department at CETMA to ask her opinion on the future of research and development of composite materials.

Alessandra Passaro, Head of Advanced Materials & Processes Consulting Department at CETMA
READING TIME

12 minutes, 30 secondes

Alessandra graduated in Materials Engineering at the University of Lecce (Italy), she is now Head of Advanced Materials & Processes Consulting Department at CETMA. She has been selected several times as an expert for the evaluation of the project proposals within the European programs: H2020, Clean Sky 2 and Horizon Europe. She has a long experience as Coordinator of European Projects and had previously gained significant professional experience as coordinator of the drafting of the project proposal in national / regional programs (building partnerships, organizing the budget, drafting the technical part). Coordinator of the numix European project, Coordinator of the European project prowaste – efficient use of plastic waste through product design and process innovation.

JEC Composites Magazine: Good morning Alessandra, thank you for agreeing to be the interviewed. How, when and why did your interest in composite materials arise ?
Alessandra Passaro, Head of Advanced Materials & Processes Consulting Department at CETMA:
“I began to work with composite materials 20 years ago, when I started to work in CETMA as junior researcher. At the beginning I just had the skills coming from the academic studies. My first experience in CETMA was related to the development of a mechanical recycling process for thermoplastic composite materials. Over the years I have realized more and more how there is a lot of work to do in terms of innovation in the field of composite materials. After twenty years, my feeling is that we are still at the beginning. This is what I like of this class of materials: there is a lot of challenges to be faced and continuously arise new opportunities, new applications, processes and material typologies, following the industrial needs on one side and the environmental issues on the other.”

CETMA, the Research and Technology Organization, is one of the largest private non-profit research centers in Italy. It has 4000 square meters laboratories and offices and 64 employees as researchers, engineers, designers and project managers, with a production turnover  of  6 million € in 2021.
CETMA, the Research and Technology Organization, is one of the largest private non-profit research centers in Italy. It has 4000 square meters laboratories and offices and 64 employees as researchers, engineers, designers and project managers, with a production turnover of 6 million € in 2021.

JEC Composites Magazine : What, in your opinion, have been the most interesting developments in the composites trade in these 20 years? If you had  to indicate a moment in which you saw a real “qualitative leap” what would you say?
Alessandra Passaro: “I think that the most interesting developments are relevant to the environmental aspects. Until few years ago, the studies on recycling of composite materials were typically confined to academic groups and the interest of the industry was quite marginal. The increasing of the European standards from one side and of the funding instruments on the other, lead the industrial world to dedicate more and more attention to these aspects. The recycling issue is not definitely solved because solutions effective from both technical and economical point of view are not yet available, in particular for the glass fiber reinforced thermosetting materials. On the other hand the several interesting materials are being developed following the eco-design approach in view of the recycling of the materials.
Other important development are established in the process automation, on the purpose to reduce the cycle time.”

JEC Composites Magazine: Composite materials have undergone tremendous development over the recent  years,  which sector was the most active bringing more innovations in the research and development?
Alessandra Passaro: “Considering my experience in CETMA, the aeronautical sector remains one of the main fields that foster the innovations for composite material, together with the automotive one due to need to reduce the vehicle weight. In both cases the industry requires for:

  • an increasing in the process automatization, for both reducing the cycle time and increasing the reliability of the processes;
  • the use of material having a higher potentiality for the implementation of effective recycling processes.

Even if the autoclave is still the process mainly used in the industries using composites, in particular the ones reinforced with continuous fibers, the world of the research and innovation is mainly focused on Out Of Autoclave processes, mainly to answer to the first need.

Prototype of a component to be installed in an equipment that will be used in a physics of particles. CETMA supports companies wishing to invest in innovation and differentiation of their range of products / services like  rapid prototyping services, pre-production series, rapid-manufacturing.
Prototype of a component to be installed in an equipment that will be used in a physics of particles. CETMA supports companies wishing to invest in innovation and differentiation of their range of products / services like rapid prototyping services, pre-production series, rapid-manufacturing.

The adoption of thermoplastic matrix composite can answer to both the mentioned industrial necessities.

Another field that is becoming more and more active is the one related to the manufacturing of tanks for hydrogen storage and transportation, where innovations on processes, designing and materials are necessary to improve the performance of the composite material tanks and reduce the costs.

I think the attention to the thermoplastic matrices remain still very high. We are working a lot on innovative solutions with thermoplastic matrix composites in particular for aerospace applications. The thermoplastic matrices let not only to increase the recycling potential of the material but also to reduce the cycle time and to automatize the processes. My sensation is that there is an increasing interesting also in the automotive field and even in wind energy. The first wind blades with Elium® have already been produced.

The innovation for the tank for hydrogen has to answer to the need to improve the manufacturing processes, to reduce the cycle time and increase the freedom in the possible geometries and winding angle of the fibers, for example by combining filament winding with Automated Fiber Placement.”

JEC Composites Magazine: Can you tell us more about your role in CETMA?
Alessandra Passaro: “I have worked for a long period on research and development activities within funded projects and consultant activities for industries. In the last years I moved more and more to a management role. At the moment I coordinate a group of 28 persons which are organised in four operative areas: 1. Innovative materials design, 2. Technologies and processes, 3. Simulation and Modelling, 4. Control and structural health monitoring. One of our strength points is the availability of integrated competencies that cover material design and optimization, processing, testing, numerical simulation of material, components and processes; this aspect is particularly significant for the composite materials where the final outcome strongly depends on each stage of the component development, from the specific composite material choice up to the process parameters optimisation.

We build our skills and expertise within funded R&D projects (both European and national projects), with the aim to be ready to propose winning innovative solutions to our industrial customers. Together with my precious colleagues, I define the specific strategic areas to be address to, I identify convenient funding instruments, both for our own R&D projects and for our customers, I interact with our main customers to verify that the outcomes of our activities fully meet their requests.”

The use of pyrolysis for the recycling of carbon fibers is one of the first recycling process that reached the industrialization, thanks to its versatility and to the possibility to obtain fibers having mechanical properties comparable with virgin ones.
The use of pyrolysis for the recycling of carbon fibers is one of the first recycling process that reached the industrialization, thanks to its versatility and to the possibility to obtain fibers having mechanical properties comparable with virgin ones.

JEC Composites Magazine : I remember your work dedicated to pyrolysis as a recycling technique, did you continue your research in the sector? Are you currently considering other opportunities? Which?
Alessandra Passaro: “We developed a procedure and a formulation for the sizing of carbon fibers coming from pyrolysis. The R&D activity was developed within a European project (REVALUE – Recycled carbon fibres for high VALUE composites – Kic raw material) and refined for industrial customers. Our sizing formulation improves the mechanical properties of the recycled carbon fiber reinforced composites up to the 30%, even more in the case of dynamic properties. We also worked on the possible manufacturing processes of recycled carbon fiber reinforced composites, including injection moulding of thermoplastic reinforced by chopped recycled carbon fibers and RTM by the use of non-woven fabric.

The use of pyrolysis for the recycling of carbon fibers is one of the first recycling process that reached the industrialization, thanks to its versatility and to the possibility to obtain fibers having mechanical properties comparable with virgin ones. However, I think that two aspects are containing a massive market penetration of the fibers coming from pyrolysis: the recycled carbon fiber cost and the need of the manufacturers of recycled carbon fiber reinforced components to redesign the component and to adopt the production processes to the new fibers that have specific peculiarities.

The recycled carbon fibers coming from pyrolysis continue to be one of our strategic R&D lines, because there are still many unsolved technical issues on one side (e.g. design methodologies addressing the specific morphology of the recycled fiber, testing methods for the measurement of the fiber length, identification and development of winning applications that valorize the recycled fiber peculiarities, etc.) and there is an increasing need to recycle the carbon fiber on the other.”

Induction welding uses electromagnetic induction to heat the workpiece by Joule effect. No additional material is needed, because the material welding occurs thanks to the melting of the thermoplastic matrix. The process is suitable for composites reinforced by carbon fibers, which act as conductive means. CETMA patented a variant of the process suitable for thermosetting materials, thank to the use of a welding film between the two surfaces to be welded.
Induction welding uses electromagnetic induction to heat the workpiece by Joule effect. No additional material is needed, because the material welding occurs thanks to the melting of the thermoplastic matrix. The process is suitable for composites reinforced by carbon fibers, which act as conductive means. CETMA patented a variant of the process suitable for thermosetting materials, thank to the use of a welding film between the two surfaces to be welded.

JEC Composites Magazine : Technological developments: what are the news regarding materials and processes? Can you give us some info concerning the composites materials utilized?
Alessandra Passaro: “As already mentioned, many of the new technological developments typically answer to the need of processes automatization. My team is cooperating more and more with the companies dealing with customized solutions for process automatization, on the purpose to propose on the market automatized lines with a contained price, that let the implementation of optimized processes fully answering to the component requirements (mechanical properties, weight, productivity, cost, etc.).

On the other hand, the environmental issues are an inescapable aspect for anybody who deals with material innovation. 

From the point of view of the matrices, the use of thermoplastic polymers can answer to the need to increase the recycling potential. CETMA, together with the main RTOs at global level, works on these materials, with both traditional polymers that already reached the market and innovative polymers such as cleavable epoxy resin, vitrimers, reactive thermoplastics. Another line of innovation that is finding more and more the industrial interest is the one related to the development of materials coming from renewable resources, that concerns both the matrix and fibers. In particular the flax fibers seem to be the ones that have already reached the industrialisation stage in some niche application for example in construction and automotive field. Hemp fibers, in spite of their very good mechanical properties, are less well developed in Europe in form of fabric: the product chain after the plantation seems to be in delay in Europe with respect to Canada and China where hemp fabrics are available at lower prices.”

The testing lab offers characterization services, as well as specialist support and assistance to identify the most appropriate analysis techniques for assessing performance of materials/components of interest to customers. All tests are carried out according to customer requirements, according to national or international regulations.
The testing lab offers characterization services, as well as specialist support and assistance to identify the most appropriate analysis techniques for assessing performance of materials/components of interest to customers. All tests are carried out according to customer requirements, according to national or international regulations.

JEC Composites Magazine : Let us consider a topic which attracts the interest of the public and  industry but that does not seem to be proceeding very satisfactorily. I’m talking of recycling. What are your considerations on the recycling state of art?
Alessandra Passaro: “Composite materials have a green feature thanks to the possibility to reduce component weight, yet on the other hand they are difficult to recycle, due to the heterogeneous nature of the material and to the use of thermosetting matrices. The first papers on composite material recycling go back to the eighties; the scientific literature is full of studies on mechanical, thermal and chemical recycling. Nevertheless, the industrialization was reached only few years ago, and there are still many limits in the use of secondary raw material coming from composite material recycling. The recycling methods that reached the market are mechanical and thermal recycling.

The first implies grinding to obtain inert fillers, leading to a very lower performance material. With the thermal recycling (i.e. pyrolysis) only the fibres are recovered while the degraded polymer matrix can be only used as energy source. In contrast to these downcycling approaches, the new trends are focused on the most promising chemical recycling, since fibres and matrix can be both recovered obtaining high value recycled materials.

However, the jump to industrialization still needs to overcome many issues:

  1. use of solvents that hinder safety and sustainability;
  2. use of non-commercial technologies (e.g. plasma, microwave-assisted systems), which compromise the scalability of the process and entails high investments;
  3. high process pressures and temperatures, which increase the economic costs and hinder the sustainability;
  4. presence of catalyst that might affect final recycled materials performance.”
CETMA developed a procedure and a formulation for the sizing of carbon fibers coming from pyrolysis. The R&D activity was developed within a European project (REVALUE – Recycled carbon fibres for high VALUE composites – Kic raw material) and refined for industrial customers.
CETMA developed a procedure and a formulation for the sizing of carbon fibers coming from pyrolysis. The R&D activity was developed within a European project (REVALUE – Recycled carbon fibres for high VALUE composites – Kic raw material) and refined for industrial customers.

JEC Composites Magazine : Recycling is directly linked with sustainability, in your opinion which are the materials that in a near future can be used replacing the current ones? To what extent can natural fibers replace glass and carbon? And “natural resins?”
Alessandra Passaro: “I always have the impression that we do a lot of talking but that in the end the reality is a different matter.

One promising approach to overcome the limits inherent to the very low recycling potential of the current composite materials consists in the development of resins with suitable chemistries in view of an effective and sustainable recycling process according to an eco-design approach. Enlarging the analysis to the general aspect of the sustainability, as already mentioned above, many research groups and industrial material developers, are working on matrices and fibers coming from renewable resources. There are many commercial products on the market.

The natural fibers, hemp and flax in particular, have the potentialities to replace the glass fibers in many applications and this is already a recent reality in some construction and automotive components. On the other hand, I think that it is difficult to substitute carbon fibers with natural ones, due to the high strength to weight ratio typically required in the case of carbon fibers use.

Yes, I think that the brand “sustainability” is often just smoke and mirror, to facilitate the selling of new materials. For example even if the substitution of thermosetting with thermoplastic matrix is presented as the solution for the recycling, real recycling methods are not yet demonstrated to be effective and economical viable on industrial scale. The high fragmentation level of the composite material value chain and the very numerous variables involved do not help in the industrialisation of the new sustainable solutions. For example, developing robust recycling processes is very difficult due to the infinite topologies of composite materials, with different matrices and different fibers.

However, even if a lot of work still needs to be done, my impression is that the industrial implementation of environmental friendly innovations cannot wait anymore. Suffice it to know the issues relevant to the dismissing of the wind farms that are arriving altogether to the end of life involving the need to dismantle a huge amount of fiberglass.

All the research group and industrial companies working with composite materials are in some way taking into account the environmental aspects and effective innovative solution will be more and more available and encouraged by European regulations.”

CETMA support companies in the process optimization and the prototype development. Prototype of an aeronautic component (keel-beam) made with PEKK-carbon composite starting from UD-tape form, assembled by CETMA by the use of Induction Welding technology.
CETMA support companies in the process optimization and the prototype development. Prototype of an aeronautic component (keel-beam) made with PEKK-carbon composite starting from UD-tape form, assembled by CETMA by the use of Induction Welding technology.

JEC Composites Magazine : The scenario of use of advanced composite materials has completely changed, the world of composite materials is constantly evolving: which projects and which new materials in our future?
Alessandra Passaro: “The future will be focused in the reduction of the environmental footprint. From the point of view of the emerging field, the one of hydrogen tanks is surely becoming more and more important form the R&D and industrial point of view.”

About the CETMA:
Founded back in 1994 CETMA is a non-profit Research and Technology Organization, carrying out applied research, supporting the innovation processes of industrial enterprises. It has 4000 square meters laboratories and offices and 64 employees as researchers, engineers, designers and project managers. The production turnover was 6 million € in 2021. CETMA’s mission is to increase and integrate enabling technologies such as Materials and Structures Engineering, Information Technology, Industrial Design, so that it positions itself as a multidisciplinary product development center. CETMA is among the largest private non-profit research centers in Italy with over 25 years of experience in studies on materials, processes, techniques and methods to support the innovation processes of industrial enterprises. In the last 20 years, CETMA invested in composite material field in terms of facilities and competencies, and it is becoming more and more a point of reference for those companies that aim to invest in innovation in this sector.

More information www.cetma.it