• Climate change, fresh water & Marine eutrophication, Freshwater ecotoxicity, Land use and Mineral fossil & ren. Resource depletion impact categories were selected as the most affected among others.
• CF, CNTs & GNPs production has a clear environmental hotspot over the composite filament production processes.
• Reinforced PA has the highest environmental impact on climate change independently of the type of reinforcement due to the fossil fuel origin production and the related emissions to air, water and soil.
• PA, PLA and PP with GNPs present higher environmental impact compared to the other reinforcements in fresh water eutrophication, marine eutrophication and land use.
• PA, PLA and PP with CNTs mainly affect the fresh water ecotoxicity.
• The majority of the developed composite filaments have a high impact on Mineral eutrophication and Fossil & renewable resource depletion.
• Accounting for all impact categories and assuming equal weight, PP with 3% CFs filament seems to be the most preferable option based on the decision making process through the LCA approach.

An innovative front wing for racing cars has been developed as a demonstrator for the Smartfan project. The aim is to produce this complex part with compression molding technique. This results in a reduction of the production costs, allowing the part to be more suitable for the large scale production. The wing will also include a self-sensing system to monitor the damage state.

To achieve this ambitious result, the parts composing the wing (i.e., the outer shells and the bulkhead), were completely redesigned for compression molding. The design of the tooling is currently under development, however, a first layout of the tooling was obtained (in the first figure, the tooling for the production of the structural bulkhead is depicted).

A mold with movable parts to produce the outer shell with the presence of an undercut is under development and will be completed in the next weeks (second figure).

In addition, a tooling for the bonding of the structural components will be developed in the next weeks.

Within the scope of SMARTFAN, CANOE is actively developing formulations and processes for nano-enabled sizing systems for carbon fibres. Main objectives are the improvement of both mechanical properties (Inter Laminar shear strength) but also but electrical conductivity of carbon fibre reinforced polymers (CFRP).

Using different kinds of nano-fillers commercially available or synthetized by NTUA, fibres are sized by CANOE and processed into CFRPs by infusion (CANOE) or pre-preg manufacturing and lay-up (INEGI). These developments have led to promising results for applications in high-end structural applications for instance.

On the other hand, CANOE is particularly involved in the manufacturing of fibres, especially from bio-based materials such as cellulose or lignin as well as carbon fibres therefrom. To complete the existing carbonization line in CANOE – on which SMARTFAN sizing developments at larger scale will be performed – a wet-spinning pilot line will be installed during summer 2020 in CANOE facilities in Lacq. This solvent spinning line will be able to produce around 3 tons of fibers per year, and will allow the spinning of various types of polymers, such as cellulose, polyvinyl alcohol, lignin, polyacrylonitrile, alginate, after dissolution in a solvent like phosphoric acid, water, DMSO, ionic liquids, among others.

In accordance with SMARTFAN goals, ELICA carried out a CFD (Computational Fluid Dynamic) optimization process in order to define the geometric properties of an axial fan (blades number and their shape in particular) to obtain maximum values of the Fluid Dynamic Efficiency (FDE), according to geometric constraints of the technological application.

On the other hand, standard safety tests were performed on plates and on a 3D printed axial fan (designed after the CFD results, shown in fig.2), moulded with different materials.

Safety tests showed that the use of the CNT filled polymer is not allowed for range hoods, but only for air treatment applications. Given the minor progress with a PP V-0 polymer, it might be interesting to test a PP with a better flammability (5VA) index of the matrix, keeping in mind that usually 5VA polymers are unsuitable for impeller moulding.

During next phase, both electrical resistance tests and fluid dynamic performance tests will be carried out on the axial fan. In particular, the impeller will be installed in a standard application to verify materials and life test.

3D printing technology has been exploited within SMARTFAN project in order to manufacture Smart-Fans for ELICA S.P.A. NTUA used an Industrial Markforged X7 3D printer, part of the SMARTFAN’s Pilot Line. This printer utilizes dual printer heads to print both composite, non-composite materials, reinforced or not with carbon fibres using a variety of filaments. Using the dual heads, the printer can produce complex lightweight items, while laser inspection scans parts mid-print to ensure dimensional accuracy for the most critical tolerances. Eiger Slicer, which is compatible with Markforged X7 3D printer, was used for the creation of .mfp file.

A polyamide-based thermoplastic filament has been used, reinforced with chopped carbon fibres and flame – retardant additives, in order to fulfil the requirements of ELICA S.P.A., regarding the flame-retardant properties of the fans that are intended to be used in domestic applications.

NTUA used designs by ELICA for the Smart-Fans and printed 5 prototypes. Also, 20 SDT plates were printed for ELICA to carry out various flammability measurements:

GWIT: Glow-wire Ignition Temperature

GWFI: Glow Wire Flammability Index

NFT: Needle-Flame Test

BPT: Ball Pressure Test

Within SMARTFAN, BioG3D is responsible for the design and development of a 3D printed processor cooling system with smart functionalities such as improved heat flow and self-morphing properties, by employing the composite filaments fabricated within the project. Up to M24, the design of the heat sink has been set, the thermoplastic materials (both composite and neat) that will be used in each part of the heat sink have been finalized and 3D printing process parameters have been optimised for each different material. Pre-programmed architectures with autonomous self-morphing properties and controlled bending function have been implemented by introducing auxetic patterns. In the upcoming period the heat sink design will be further elaborated, and design specifications will be optimised to achieve increased functionality in terms of heat flow and optimal air flow through responsiveness to thermal stimuli.

BioG3D has also established a pilot line for manufacturing 3D printed bioinspired structures, incorporating an FFF 3D printing system, 3D scanner and 3D design software for 3D model development and an infrared thermal camera for monitoring thermal managing materials. To facilitate the use of this pilot line, targeted protocols and recommendations regarding process parameters modifications and materials behavior have been created. Additionally, towards the development of a 3D printing system that can accommodate continuous CFs 3D printing, a modified heatblock of a commercial FFF 3D printer is under development to print both thermoplastic materials and continuous CFs simultaneously. The innovative heatblock, will be used in SMARTFAN’s pilot line, allowing the use of different abrasive materials in combination with thermoplastic filaments.

·      One of the main tasks of Forth during this period was the production, characterization and provision to SMARTFAN partners of Self-healing capsules.

·      Initially the optimal sequestration method for the healing agent and polymerizing agent has to be determined. This sequestration can be achieved through encapsulation or phase separation.

·      The standard recipe for the preparation of PUF/DCPD microcapsules was adapted from that of Brown et al. [1].

·      In order to confirm that DCPD monomer was enclosed in the UF capsules DSC measurements were taken place.

·      To evaluate the healing effect of self-activated samples fracture toughness test was also held, similarly to GFRP system up to 50mm displacement. The modified CFRP samples presented the same mechanical behaviour as the neat (virgin) samples. For the modified specimens, at the end of the first loading, they restored to their initial status (zero loading) and left to heal for 48 hours. The results were promising as the modified specimens reached an average 80% of their initial maximum load.

The abovementioned research was carried out during the M12-M24 period of the project, mainly as a part of Work Packages 1 & 2.

[1]Brown, E.N., Kessler, M.R., Sottos, N.R. & White, S.R. 2003. In situ poly(urea-formaldehyde) microencapsulation of dicyclopentadiene. Journal of Microencapsulation 20: 719-730.

The Department of Industrial Engineering of the University of Rome Tor Vergata has produced the first lab-scale prototype of a smart grabbing device with shape memory polymer composites (SMPC) and integrated heating system. This device is obtained by assembling SMPC “fingers” to form the grabbing hand. Compression molding was used to manufacture carbon fiber laminates with interposed shape memory layer. The proposed architecture of the finger allows producing functional modular structures with different operational configurations. External power supply devices were used to provide the required voltage (22 V) to heat the device for both memory and recovery phase of the grabbing devices. Different tests were performed on flat objects (PCB) to show the grabbing ability and good results were achieved. Next steps will be to scale up the size of the grabbing device and to automate the memory stage of composite assembly. The use of consolidated manufacturing technologies and the interesting properties of the SMPCs are the driving forces for their diffusion for “in Space” and “on Earth” applications.