Final Report Summary - GREENGELAIR (Application of a new “green” sol-gel product using an original, versatile, accurate and in-line mixing device that improves the adhesion of paint on aeronautical sector products.)
Executive Summary:
Executive summary
The GreenGELAIR project has been carried out between GALVATEC, an industrial SME working in surface treatments for the AERO sector and two leading RTD providers, UC3M as expertise in sol-gel processes and AIMME as metal processing technological centre and acting as leader of the consortium.
GreenGELAIR project has developed an improved sol-gel coating with prolonged lifetimes and high corrosion resistance. Also a versatile, novel and accurate formulating and application device has been design and constructed.
Firstly a series of novel Sol-gel formulations were established and optimized at lab-scale. Induction time, pot-life and chemical structure were defined using FTIR, RMN, Viscosity values and TG/DSC in the case of study the thermal stability. Based on the characterization data, the most adequate formulations for each application were proposed.
In these conditions the corrosion resistance and adhesion properties were measured using EIS and pull-off test applying the sol-gel by means of a dip-coater device.
The work followed with the optimization of the processing to higher amounts, industrial surface treatment and curing conditions adapted for each spray, brush and stick application.
In this context, a novel, versatile, accurate and in-line formulating device was designed and constructed. This device has enabled us to formulate higher amounts of sol-gel product in an easy and reproducible way controlling the dosage, flow and the nature of the reagents. Cleaning and priming sequences have been defined in order to reproduce the optimal conditions in the device. The device is controlled using a programming sequence that takes into account the chemistry formulation.
The results indicated that the processing conditions such as surface treatment, application process and cure temperature play an important role in the final coating properties. In this way a new and effective physical-chemical characterization methodology was developed to improve the quality of the sol-gel product. Viscosity, turbidity, pH and particle size analysis were studied and they defined the operational parameters in the sol-gel formulation process using the device.
The assessment of the coating has been carried out in test-pieces in AIMME facilities by means electrochemical techniques in terms of corrosion resistance using different application systems and from them, the optimal formulation and the optimal operational conditions have been selected.
Demonstration activities were performed in GALVATEC Company after establishing the optimal procedure to fabricate, treat the surface and apply sol-gel using different devices and painting systems in the AIMME facilities.
Afterwards pilot-scale trials following painting industrial procedures were conducted under the direction of GALVATEC employing the best performing formulations produced by the new device and managed by AIMME. Also, conventional pre-treatments such as TSA or Alodine were performed in GALVATEC in order to make the technical comparison with sol-gel coatings.
These sol-gel coated pieces and pieces coated by conventional pretreatments were subjected to the final characterization and performance tests according to the different standards for final product validation. Filiform corrosion, Salt Spray Chamber test, Dry/Wet adhesion, pull-off adhesion and electrochemical corrosion were carried out in OEM and MRO simulating situations for all pre-treatments studied (sol-gel and conventional).
Also, the results of the sol-gel coating were compared to those of other sol-gel products on the market that are currently used in the metal finishing industry.
As an outcome of the project, new improved low-VOC ecological coating materials with prolonged lifetimes, application protocols and formulating device are available for the MRO and OEM operations. Successful technical results have been obtained in terms of corrosion resistance and the formulation device would be ready to be implemented into a further scaled-up after carrying out the necessary capital investment on the part of the SMEs.
Project Context and Objectives:
Summary description of project context and objectives
The development of new environment-friendly corrosion protection coatings which are highly adherent to ensure their durability is one of the main objectives in the aeronautical sector. This situation is mainly motivated by environmental regulations together with high maintenance costs. In this regard, the results of the GreenGELAIR project will provide a new system of application of innovative coatings for the aeronautical sector. This system, based on sol-gel developments, will be eco-friendly and will achieve high performance in terms of adhesion and protection against aluminum corrosion. In addition, a new and versatile application device, specific for this innovative coating, has been designed and built facilitating their use both for maintenance, MRO, as in the manufacture of new equipment, OEM.
The main objectives are:
• To develop new environmentally-friendly protective sol-gel based coating with low VOC contents to address the specific needs of the aeronautical sector with the following properties:
o Induction time below 30 minutes
o Pot life around 10 h
o Easy to apply using different application systems: brush, spray and stick
o To fulfil of the environmental issues related to coatings in aeronautical sector
• Establish the production of sol-gel at pilot scale level and validate it with a new prototype in small industry scale. This prototype must accomplish:
o Accurate way to dose different components.
o Versatile mixing system that the desired quantity.
o An integrated cleaning system.
o No chemical interactions between the reagents and the mixture with the application device. Also, the materials and components should have no adverse effect on the final properties of the sol gel coating.
• Evaluation of coating and painting system
o Electrochemical control (Electrochemical impedance spectroscopy (EIS) is used to evaluate film performances and assess the corrosion resistance of sol-gel coating and the painting system as a whole.
o Highly adherent and corrosion resistant coating in terms of resistance to filiform corrosion, crevice corrosion and good wet/dry adhesion.
Project Results:
Description of main S&T results/foregrounds
GreenGELAIR project has been carried out to reach a new sol-gel product using a new application device in optimal operational conditions that ensuring a good corrosion resistance.
In this way the following S&T results has been achieved.
o Formulation of the Sol-Gel product at lab scale
Formulation of a new hybrid sol-gel product and its characterization parameters have been well defined: kinetic of hydrolysis, induction time and pot life. An optimal molar ratio of organopolysiloxanes:alcohol:water has been selected. Different testing systems were performed in different mediums and reagents chosen due to non-toxic features and low prices, being its environmentally-green properties the main factors of the difference between other commercial products.
In relation with the induction time, it has been proved that 5 minutes of reaction is enough to reach the hydrolysis-condensation stage desired. However, it is recommended that the reaction lasts at least 15-30 minutes because the sol-gel behaviour against electrochemical corrosion is the most adequate at this time. In the case of pot life, it has been determined that above 10 hours of hydrolysis-condensation reaction the deposition of the sol-gel is adequate.
TGA/DSC analysis shows that PPZ don’t induce changes into the hybrid network and 29Si-NMR spectroscopy results have confirmed an adequate degree of condensation and a typical organosilica network of the sol-gel product developed. Besides, it has been observed that the addition of PPZ induces slightly changes in the sol-gel cross-linkages; however, the sol-gel characteristics don’t get worse with the addition of PPZ. Moreover, PPZ addition improves substantially the behaviour of 2024-T3 substrate coated with sol-gel against electrochemical corrosion.
On the other hand, curing procedure at 120ºC for 30 minutes of coated samples has shown a better behaviour against electrochemical corrosion in relation to curing procedure at room temperature.
In order to evaluate the properties of the sol-gel product in lab scale the coatings were prepared by means dip-coating method. Electrochemical analysis techniques have been used to optimize the formulation parameters. The results presented high-performance adhesion as well as anticorrosive properties. The pull-off tests carried out on the resulting film coated by dip-coating technique have shown adhesion values between 6-2 MPa into the pot life defined. Also, the EIS measures after 30 days of exposure to aggressive medium (0.5%w NaCl aqueous solutions) showed good corrosion resistance values (1E+06 ohms/cm2), two orders of magnitude higher in relation to nude material.
o Application and formulation device
New and versatile device capable of reproduce the chemical process developed in the lab scale has been designed. This Sol-gel formulation device has been designed as a portable mixing panel, compact and easy to use.
A study about the chemical compatibility of the different components with the reagents used in the formulation has been taken into account and all the components of the equipment have been tested before to design and built. Also, it has been demonstrated that the materials and components have no adverse effect on the final properties of the sol gel coating.
The process has been automatized in order to promote the best reaction conditions and repeatability. To ensure this, an accurate way to dose different components by means a tailored designed system through syringes and valves has been developed. Although the programming of the sequences has been developed in order to ease its manipulation, also the user can arrange new sequences or vary the original formulation to adapt to industrial conditions or optimize any suitable parameter. Device’s versatile programming allows the user to produce the product sol-gel in batches within an accurate open range between 100ml and 2000ml. This programming is reduced to basic operations so versatility is open to user’s combinations.
The main chemical process of the sol-gel reaction determines that device works in batches with an induction time of 30 minutes to ensure the optimum properties for the product application ensuring all the achievements made during the previous studies.
During the rheological tests, the behavior of the reagents involved presented a huge reactivity with humidity and oxygen being altered in a small period of time, so through the device specific design and maintenance procedures safety and repeatability are ensured. Design has been carried out to minimize residues, being these the result of the internal device cleaning system, this ensuring no altered reagent can interfere in the following production.
o Adjustment of chemical process and application system: scale-up
Optimal operational conditions and physical-chemical parameters have been established to operate with the formulation device. These have been fixed using electrochemical techniques to assess the coating corrosion resistance as control parameter. The best behaviour against corrosion determinates the optimal operational conditions.
A new methodology to ensure the quality of sol-gel product has been described means a common and easy physical-chemical characterization. Turbidity and viscosity values depend on the sol-gel quality properties and the particle size is directly related with the hydrolysis-condensation reactions. A sol-gel product with high turbidity values presents a resistance against corrosion lower than another with low turbidity values.
Also, spray, brush and stick application were assessed using electrochemical corrosion technique simulating industrial conditions in AIMME and GALVATEC facilities.
Finally, curing temperature and surface treatment of the aluminium had got an important role in the final quality of the coating in terms of corrosion resistance. Therefore different protocols to apply and pre-treat the surface were described and assessed using electrochemical corrosion techniques in order to optimize the painting system as a whole. In this way, corrosion resistance values reached impedances above 1E+07 ohms after 30 days of immersion in 0,5%wt NaCl.
o Demonstration on an industrial scale
Finally, demo activities were carried out in GALVATEC to get in industrial environ the coating assessment. Filiform corrosion, salt spray chamber test, dry/wet adhesion test, pull-off test and electrochemical corrosion test were performed to assess the corrosion resistance and adhesion properties of the parts coated in GALVATEC facilities.
Sol-gel product was produced in-situ using the device and applied by spray in industrial conditions. In parallel pieces coated by sol-gel were compared with other conventional processes: TSA in OEM simulations and Alodine in MRO simulations. All of them following painting systems formed by pre-treatment + primer and pre-treatment + primer + top-coat.
The parts pre-treated with TSA and sol-gel product showed good results in filiform corrosion and salt spray corrosion. Adhesion tests did not achieve as good results as expected probably due to weak chemical interaction with the solventborne primer used. This fact caused adhesive failure between primer and sol-gel coating instead of cohesive failure. Future tasks using waterborne primers should be conducted in this regard in order to accomplish with the requirements above described and pass the hard quality controls of aeronautical sector.
In general terms, EIS measures of sol-gel coated parts after 30 days of exposure to aggressive medium (0.5%w NaCl aqueous solutions) showed good corrosion resistance values in OEM and MRO conditions reaching values higher than 1E+07 ohms. In MRO conditions stick application was studied and several systems were assessed as application and storage system.
Potential Impact:
Potential impact
The aviation industry’s global economic impact is 3.5 per cent of global GDP. Passenger demand doubles every 15 years and by 2050 it could be handling 16 billion passengers and 400 million tonnes of cargo annually. Only in USA more than 14.000 aircrafts are currently flying, and sales of new aircraft by 2020 are expected to be around 12,000 at an estimated cost of 1.3 trillion, and for these, operations like painting and repairing are key issues both in MRO and OEM.
The results from GreenGELAIR could be applied to MRO and OEM in whatever sort of aircraft (commercial, military...) and will fit in the environmental policy in aeronautical sector.
GreenGELAIR project contributes to minimize the following impacts addressed to aeronautical sector:
Reduce maintenance operations
In the case of functional properties, there are large economic incentives to increase the performance lifetimes of aircraft coatings. Corrosion-related problems are the number one maintenance cost to the USA Air Force (est. $700M per year) and paint-related corrosion consumes about 15% of this cost.
In this way, GreenGELAIR minimizes the maintenance cost in aircrafts. Sol-gel product has demonstrated good results as protection by barrier effect. Also, GreenGELAIR product showed corrosion resistance values much better than other sol-gel commercial products and even overcoming TSA process in some quality tests.
More ecological processes
- Obtaining a new free-chrome alternative process to CCC for using in MRO situations, touch-up or in very small surfaces for applying in stick.
- Obtaining a new alternative process to electrochemical process (as TSA) to work in OEM situations saving energy, water, wastewater produced and hazardous wastes such in process as in maintenance operations. Sol-gel is applied in a painting cabin not in an electrochemical plant therefore does not need temperature, rinsewater, and energy related to anodize process.
Alternative to current “kit” system to supply sol-gel products
- Providing a new application device for sol-gel processes on-line and tailored-to-user, versatile and easy to use. It avoids an excess of ready-to-use product. Kit system generates sol-gel products wastes due to its limited shelf life.
GreenGELAIR has designed and built a new versatile in-situ application and formulation device. This device allows fabricating in a wide range, between 100 ml to 2000 ml sol-gel product in one stage. Furthermore, the sol-gel product developed in GreenGELAIR has got a chemical estimated cost of 50 €/liter. This cost is cheaper than the cost of commercial sol-gel products.
Corrosion protection is one of the most critical issues in aeronautical sector with high economic and ecological importance. And the development of new ecofriendly protective coatings is one of the challenges worldwide in whatever industrial sector. Maintenance and repair operations move large amounts of money because of poor corrosion resistance coatings. GreenGELAIR project develops ecofiendly protective coatings using a versatile and in-situ device fitted to OEM and MRO activities of aeronautical sector.
Main dissemination activities and exploitation results
- Regular publications on partner’s website. www.aimme.es www.uc3m.es www.uc3m.esinfocientifica.
For example: http://portal.uc3m.es/portal/page/portal/actualidad_cientifica/noticias/pinturas_aviones
- A specific project Website: http://greengelair.aimme.es/
• Publications in technical journals and technical websites:
http://www.interempresas.net/MetalMecanica/Articulos/115685-Nuevo-sistema-aplicacion-para-recubrimientos-innovadores-sol-gel-para-sector-aeronautico.html
https://www.interempresas.net/Deformacion-y-chapa/Articulos/119047-Nuevo-sistema-aplicacion-para-recubrimientos-innovadores-sol-gel-para-sector-aeronautico.html?R=102661
Articles
Técnica y tecnología_Interempresas_Nuevo sistema de aplicación para recubrimientos innovadores sol gel para el sector aeronáutico_Febrero 2014, p.2-5
A. Valero Gómez, A. Jiménez Morales, F. de la Vega Náñez.
Others channels
Madrid org. http://www.madrimasd.org/informacionidi/noticias/noticia.asp?id=59338&origen=notiweb_suplemento&dia_suplemento=lunes&seccion=noticiaslunes
Ingenieros.es http://www.ingenieros.es/noticias/ver/proyecto-greengelair-cambio-de-tecnologia-para-el-pintado-en-el-sector-aeronautico/4302
Following dissemination activities are currently being carried out: a scientific publication relating to the foreground of the project in a peer-reviewed journal.
List of Websites:
website: www.greengelair.com
contact: info@greengelair.com
Executive summary
The GreenGELAIR project has been carried out between GALVATEC, an industrial SME working in surface treatments for the AERO sector and two leading RTD providers, UC3M as expertise in sol-gel processes and AIMME as metal processing technological centre and acting as leader of the consortium.
GreenGELAIR project has developed an improved sol-gel coating with prolonged lifetimes and high corrosion resistance. Also a versatile, novel and accurate formulating and application device has been design and constructed.
Firstly a series of novel Sol-gel formulations were established and optimized at lab-scale. Induction time, pot-life and chemical structure were defined using FTIR, RMN, Viscosity values and TG/DSC in the case of study the thermal stability. Based on the characterization data, the most adequate formulations for each application were proposed.
In these conditions the corrosion resistance and adhesion properties were measured using EIS and pull-off test applying the sol-gel by means of a dip-coater device.
The work followed with the optimization of the processing to higher amounts, industrial surface treatment and curing conditions adapted for each spray, brush and stick application.
In this context, a novel, versatile, accurate and in-line formulating device was designed and constructed. This device has enabled us to formulate higher amounts of sol-gel product in an easy and reproducible way controlling the dosage, flow and the nature of the reagents. Cleaning and priming sequences have been defined in order to reproduce the optimal conditions in the device. The device is controlled using a programming sequence that takes into account the chemistry formulation.
The results indicated that the processing conditions such as surface treatment, application process and cure temperature play an important role in the final coating properties. In this way a new and effective physical-chemical characterization methodology was developed to improve the quality of the sol-gel product. Viscosity, turbidity, pH and particle size analysis were studied and they defined the operational parameters in the sol-gel formulation process using the device.
The assessment of the coating has been carried out in test-pieces in AIMME facilities by means electrochemical techniques in terms of corrosion resistance using different application systems and from them, the optimal formulation and the optimal operational conditions have been selected.
Demonstration activities were performed in GALVATEC Company after establishing the optimal procedure to fabricate, treat the surface and apply sol-gel using different devices and painting systems in the AIMME facilities.
Afterwards pilot-scale trials following painting industrial procedures were conducted under the direction of GALVATEC employing the best performing formulations produced by the new device and managed by AIMME. Also, conventional pre-treatments such as TSA or Alodine were performed in GALVATEC in order to make the technical comparison with sol-gel coatings.
These sol-gel coated pieces and pieces coated by conventional pretreatments were subjected to the final characterization and performance tests according to the different standards for final product validation. Filiform corrosion, Salt Spray Chamber test, Dry/Wet adhesion, pull-off adhesion and electrochemical corrosion were carried out in OEM and MRO simulating situations for all pre-treatments studied (sol-gel and conventional).
Also, the results of the sol-gel coating were compared to those of other sol-gel products on the market that are currently used in the metal finishing industry.
As an outcome of the project, new improved low-VOC ecological coating materials with prolonged lifetimes, application protocols and formulating device are available for the MRO and OEM operations. Successful technical results have been obtained in terms of corrosion resistance and the formulation device would be ready to be implemented into a further scaled-up after carrying out the necessary capital investment on the part of the SMEs.
Project Context and Objectives:
Summary description of project context and objectives
The development of new environment-friendly corrosion protection coatings which are highly adherent to ensure their durability is one of the main objectives in the aeronautical sector. This situation is mainly motivated by environmental regulations together with high maintenance costs. In this regard, the results of the GreenGELAIR project will provide a new system of application of innovative coatings for the aeronautical sector. This system, based on sol-gel developments, will be eco-friendly and will achieve high performance in terms of adhesion and protection against aluminum corrosion. In addition, a new and versatile application device, specific for this innovative coating, has been designed and built facilitating their use both for maintenance, MRO, as in the manufacture of new equipment, OEM.
The main objectives are:
• To develop new environmentally-friendly protective sol-gel based coating with low VOC contents to address the specific needs of the aeronautical sector with the following properties:
o Induction time below 30 minutes
o Pot life around 10 h
o Easy to apply using different application systems: brush, spray and stick
o To fulfil of the environmental issues related to coatings in aeronautical sector
• Establish the production of sol-gel at pilot scale level and validate it with a new prototype in small industry scale. This prototype must accomplish:
o Accurate way to dose different components.
o Versatile mixing system that the desired quantity.
o An integrated cleaning system.
o No chemical interactions between the reagents and the mixture with the application device. Also, the materials and components should have no adverse effect on the final properties of the sol gel coating.
• Evaluation of coating and painting system
o Electrochemical control (Electrochemical impedance spectroscopy (EIS) is used to evaluate film performances and assess the corrosion resistance of sol-gel coating and the painting system as a whole.
o Highly adherent and corrosion resistant coating in terms of resistance to filiform corrosion, crevice corrosion and good wet/dry adhesion.
Project Results:
Description of main S&T results/foregrounds
GreenGELAIR project has been carried out to reach a new sol-gel product using a new application device in optimal operational conditions that ensuring a good corrosion resistance.
In this way the following S&T results has been achieved.
o Formulation of the Sol-Gel product at lab scale
Formulation of a new hybrid sol-gel product and its characterization parameters have been well defined: kinetic of hydrolysis, induction time and pot life. An optimal molar ratio of organopolysiloxanes:alcohol:water has been selected. Different testing systems were performed in different mediums and reagents chosen due to non-toxic features and low prices, being its environmentally-green properties the main factors of the difference between other commercial products.
In relation with the induction time, it has been proved that 5 minutes of reaction is enough to reach the hydrolysis-condensation stage desired. However, it is recommended that the reaction lasts at least 15-30 minutes because the sol-gel behaviour against electrochemical corrosion is the most adequate at this time. In the case of pot life, it has been determined that above 10 hours of hydrolysis-condensation reaction the deposition of the sol-gel is adequate.
TGA/DSC analysis shows that PPZ don’t induce changes into the hybrid network and 29Si-NMR spectroscopy results have confirmed an adequate degree of condensation and a typical organosilica network of the sol-gel product developed. Besides, it has been observed that the addition of PPZ induces slightly changes in the sol-gel cross-linkages; however, the sol-gel characteristics don’t get worse with the addition of PPZ. Moreover, PPZ addition improves substantially the behaviour of 2024-T3 substrate coated with sol-gel against electrochemical corrosion.
On the other hand, curing procedure at 120ºC for 30 minutes of coated samples has shown a better behaviour against electrochemical corrosion in relation to curing procedure at room temperature.
In order to evaluate the properties of the sol-gel product in lab scale the coatings were prepared by means dip-coating method. Electrochemical analysis techniques have been used to optimize the formulation parameters. The results presented high-performance adhesion as well as anticorrosive properties. The pull-off tests carried out on the resulting film coated by dip-coating technique have shown adhesion values between 6-2 MPa into the pot life defined. Also, the EIS measures after 30 days of exposure to aggressive medium (0.5%w NaCl aqueous solutions) showed good corrosion resistance values (1E+06 ohms/cm2), two orders of magnitude higher in relation to nude material.
o Application and formulation device
New and versatile device capable of reproduce the chemical process developed in the lab scale has been designed. This Sol-gel formulation device has been designed as a portable mixing panel, compact and easy to use.
A study about the chemical compatibility of the different components with the reagents used in the formulation has been taken into account and all the components of the equipment have been tested before to design and built. Also, it has been demonstrated that the materials and components have no adverse effect on the final properties of the sol gel coating.
The process has been automatized in order to promote the best reaction conditions and repeatability. To ensure this, an accurate way to dose different components by means a tailored designed system through syringes and valves has been developed. Although the programming of the sequences has been developed in order to ease its manipulation, also the user can arrange new sequences or vary the original formulation to adapt to industrial conditions or optimize any suitable parameter. Device’s versatile programming allows the user to produce the product sol-gel in batches within an accurate open range between 100ml and 2000ml. This programming is reduced to basic operations so versatility is open to user’s combinations.
The main chemical process of the sol-gel reaction determines that device works in batches with an induction time of 30 minutes to ensure the optimum properties for the product application ensuring all the achievements made during the previous studies.
During the rheological tests, the behavior of the reagents involved presented a huge reactivity with humidity and oxygen being altered in a small period of time, so through the device specific design and maintenance procedures safety and repeatability are ensured. Design has been carried out to minimize residues, being these the result of the internal device cleaning system, this ensuring no altered reagent can interfere in the following production.
o Adjustment of chemical process and application system: scale-up
Optimal operational conditions and physical-chemical parameters have been established to operate with the formulation device. These have been fixed using electrochemical techniques to assess the coating corrosion resistance as control parameter. The best behaviour against corrosion determinates the optimal operational conditions.
A new methodology to ensure the quality of sol-gel product has been described means a common and easy physical-chemical characterization. Turbidity and viscosity values depend on the sol-gel quality properties and the particle size is directly related with the hydrolysis-condensation reactions. A sol-gel product with high turbidity values presents a resistance against corrosion lower than another with low turbidity values.
Also, spray, brush and stick application were assessed using electrochemical corrosion technique simulating industrial conditions in AIMME and GALVATEC facilities.
Finally, curing temperature and surface treatment of the aluminium had got an important role in the final quality of the coating in terms of corrosion resistance. Therefore different protocols to apply and pre-treat the surface were described and assessed using electrochemical corrosion techniques in order to optimize the painting system as a whole. In this way, corrosion resistance values reached impedances above 1E+07 ohms after 30 days of immersion in 0,5%wt NaCl.
o Demonstration on an industrial scale
Finally, demo activities were carried out in GALVATEC to get in industrial environ the coating assessment. Filiform corrosion, salt spray chamber test, dry/wet adhesion test, pull-off test and electrochemical corrosion test were performed to assess the corrosion resistance and adhesion properties of the parts coated in GALVATEC facilities.
Sol-gel product was produced in-situ using the device and applied by spray in industrial conditions. In parallel pieces coated by sol-gel were compared with other conventional processes: TSA in OEM simulations and Alodine in MRO simulations. All of them following painting systems formed by pre-treatment + primer and pre-treatment + primer + top-coat.
The parts pre-treated with TSA and sol-gel product showed good results in filiform corrosion and salt spray corrosion. Adhesion tests did not achieve as good results as expected probably due to weak chemical interaction with the solventborne primer used. This fact caused adhesive failure between primer and sol-gel coating instead of cohesive failure. Future tasks using waterborne primers should be conducted in this regard in order to accomplish with the requirements above described and pass the hard quality controls of aeronautical sector.
In general terms, EIS measures of sol-gel coated parts after 30 days of exposure to aggressive medium (0.5%w NaCl aqueous solutions) showed good corrosion resistance values in OEM and MRO conditions reaching values higher than 1E+07 ohms. In MRO conditions stick application was studied and several systems were assessed as application and storage system.
Potential Impact:
Potential impact
The aviation industry’s global economic impact is 3.5 per cent of global GDP. Passenger demand doubles every 15 years and by 2050 it could be handling 16 billion passengers and 400 million tonnes of cargo annually. Only in USA more than 14.000 aircrafts are currently flying, and sales of new aircraft by 2020 are expected to be around 12,000 at an estimated cost of 1.3 trillion, and for these, operations like painting and repairing are key issues both in MRO and OEM.
The results from GreenGELAIR could be applied to MRO and OEM in whatever sort of aircraft (commercial, military...) and will fit in the environmental policy in aeronautical sector.
GreenGELAIR project contributes to minimize the following impacts addressed to aeronautical sector:
Reduce maintenance operations
In the case of functional properties, there are large economic incentives to increase the performance lifetimes of aircraft coatings. Corrosion-related problems are the number one maintenance cost to the USA Air Force (est. $700M per year) and paint-related corrosion consumes about 15% of this cost.
In this way, GreenGELAIR minimizes the maintenance cost in aircrafts. Sol-gel product has demonstrated good results as protection by barrier effect. Also, GreenGELAIR product showed corrosion resistance values much better than other sol-gel commercial products and even overcoming TSA process in some quality tests.
More ecological processes
- Obtaining a new free-chrome alternative process to CCC for using in MRO situations, touch-up or in very small surfaces for applying in stick.
- Obtaining a new alternative process to electrochemical process (as TSA) to work in OEM situations saving energy, water, wastewater produced and hazardous wastes such in process as in maintenance operations. Sol-gel is applied in a painting cabin not in an electrochemical plant therefore does not need temperature, rinsewater, and energy related to anodize process.
Alternative to current “kit” system to supply sol-gel products
- Providing a new application device for sol-gel processes on-line and tailored-to-user, versatile and easy to use. It avoids an excess of ready-to-use product. Kit system generates sol-gel products wastes due to its limited shelf life.
GreenGELAIR has designed and built a new versatile in-situ application and formulation device. This device allows fabricating in a wide range, between 100 ml to 2000 ml sol-gel product in one stage. Furthermore, the sol-gel product developed in GreenGELAIR has got a chemical estimated cost of 50 €/liter. This cost is cheaper than the cost of commercial sol-gel products.
Corrosion protection is one of the most critical issues in aeronautical sector with high economic and ecological importance. And the development of new ecofriendly protective coatings is one of the challenges worldwide in whatever industrial sector. Maintenance and repair operations move large amounts of money because of poor corrosion resistance coatings. GreenGELAIR project develops ecofiendly protective coatings using a versatile and in-situ device fitted to OEM and MRO activities of aeronautical sector.
Main dissemination activities and exploitation results
- Regular publications on partner’s website. www.aimme.es www.uc3m.es www.uc3m.esinfocientifica.
For example: http://portal.uc3m.es/portal/page/portal/actualidad_cientifica/noticias/pinturas_aviones
- A specific project Website: http://greengelair.aimme.es/
• Publications in technical journals and technical websites:
http://www.interempresas.net/MetalMecanica/Articulos/115685-Nuevo-sistema-aplicacion-para-recubrimientos-innovadores-sol-gel-para-sector-aeronautico.html
https://www.interempresas.net/Deformacion-y-chapa/Articulos/119047-Nuevo-sistema-aplicacion-para-recubrimientos-innovadores-sol-gel-para-sector-aeronautico.html?R=102661
Articles
Técnica y tecnología_Interempresas_Nuevo sistema de aplicación para recubrimientos innovadores sol gel para el sector aeronáutico_Febrero 2014, p.2-5
A. Valero Gómez, A. Jiménez Morales, F. de la Vega Náñez.
Others channels
Madrid org. http://www.madrimasd.org/informacionidi/noticias/noticia.asp?id=59338&origen=notiweb_suplemento&dia_suplemento=lunes&seccion=noticiaslunes
Ingenieros.es http://www.ingenieros.es/noticias/ver/proyecto-greengelair-cambio-de-tecnologia-para-el-pintado-en-el-sector-aeronautico/4302
Following dissemination activities are currently being carried out: a scientific publication relating to the foreground of the project in a peer-reviewed journal.
List of Websites:
website: www.greengelair.com
contact: info@greengelair.com