HUN-REN-BME Research Group





Industry 4.0 assisted, one-pot manufacturing of valued-added polymer systems with multifunctional coating in the first step for automotive industry and extending to further marketable application fields

Project ID:
2018-1.3.1-VKE-2018-00011
Supported by:
Hungarian National Research, Development and Innovation Office (NKFIH)
Term:
1 April 2019 - 30 September 2022
Supervisor (BME):
Prof. Dr. Andrea Toldy

Participant researchers (BME):
Prof. Dr. Andrea Toldy
Dr. Ákos Pomázi
Zsófia Kovács
Martin Krecz
Tamás Temesi
Bertalan Papp
Dr. Gábor Romhány
Dr. Zoltán Tamás Mezey
Consortium partners (BME):
PEMÜ Műanyagipari Zártkörűen Működő Részvénytársaság

Project summary

The widespread propagation of dynamically developing polymer engineering applications is hindered by the flammability of the polymer matrix in many areas. The increasingly stringent safety requirements necessitate the effective flame retardancy of the polymer systems used, while maintaining or possibly improving their mechanical and other properties. In addition to the use of flame retardants in the matrix, it is a particularly effective flame retardancy method when the flame retardant polymer is applied as a coating to the outer surface of the composite. The advantage of the multilayer structure is that the flame retardant does not reduce the mechanical properties and the glass transition temperature of the base polymer, and the targeted flame retardancy on the surface makes it possible to reduce the amount of additive necessary,which is both a cost reduction and environmentally advantageous. From the processing point of view it is also advantageous that this method avoids the unequal distribution and elimination of solid-phase flame retardants in injection technologies. However, previously developed coatings did not provide adequate aesthetic quality and mechanical protection, weather resistance, abrasion and abrasion resistance were limited. These disadvantages can be eliminated through multifunctional so-called gelcoat type coatings. By using gelcoat, the desired functions can be assured without altering the array-phase properties of the composite component. The common feature of the present application methods is that the coating is subsequently applied in a separate step to the finished product, making it difficult to increase the size and automation of the manufacturing technology. The aim of the project is to develop a customizable coating family that can meet the specific needs of the automotive industry and other industries and allow the application of the coating in the same technological step as the product. The desired properties are obtained by mixing the appropriate components in required proportions. Combined additive systems are also used to produce multifunctional (e.g. flame retardant, antistatic, conductive, UV-resistant, heat-resistant) coatings. From the technological implementation point of view, it is a significant advancement that the delivery of the main component of the product to the mould and the coating is made in the same manufacturing unit. The key to the reliable production of coated products from polyolefin made by injection moulding (e.g. sun visor, waste bin) and from polyurethane made by foaming (e.g.car mats,cushions) is the quality control and regulation implemented at the same time as the manufacturing process, which we plan to realize by the introduction of industry 4.0 information technology platform. The result of the development is to increase the competitiveness and production efficiency of PEMÜ, to continuously ensure and improve the quality of the product and to continuously optimize the efficiency of energy use. The customizable coating family and one-step coating technology to be developed as well as the results of the adaptation of industry 4.0 methods will be widely used in all industries where strict security requirements apply, but the productivity, up-scaling and automation of the manufacturing process is also important. Adaptable coatings will be suitable for the environmentally friendly surface modification and flame retardancy of many technical polymers and thermoplastic commodity polymers. In addition to the benefits of reduced flammability and toxicity, the development provides an environmentally friendly alternative to the polymer product market and provides a competitive price level due to the application of commodity polymer matrix, decreased amount of additive as a result of the coating, single-step manufacturing technology and the introduction of in-line quality control to the manufacturing process and immediate feedback minimizing the amount of production waste.

Project results

Section 1
1 April 2019 - 31 Marc 2020
We produced new phosphorus-containing flame retardants and additive combinations, and then developed new flame retardant coatings using them. Based on the results of the flammability tests, the increasing phosphorus content improves the flame retardancy of the coatings: even with the lowest applied, 5% phosphorus content, the developed coating has reached a self-extinguishing, V-0 grade. The coatings were then applied to reference and flame retardant reference polymer samples, followed by flammability (LOI, UL-94 and mass loss type cone calorimetry (MLC)), mechanical (dynamic mechanical analysis (DMA) and three-point bending) and adhesion tests. At 10% phosphorus content, the developed coating reached the flame retardancy level of the commercially available product, while the coating with 15% phosphorus content already significantly exceeded it. By increasing the concentration of ammonium polyphosphate (APP) in the solid phase, the so-called intumescent nature of the coating also intensified. We investigated the feasibility of spraying and one-step coating technologies and selected the most promising formulations for industrial use

Section 2
1 April 2020 - 31 Marc 2021
Based on the results of the first project phase, BME has selected and produced the most promising new flame retardants and new additive systems in the quantities required for further testing. These were then used to produce multifunctional coatings that could potentially be applied in a single-step process. Based on the rheological test results, two solutions were developed to facilitate the industrial application of high viscosity coatings. Firstly, we prepared and tested modified formulations in which low viscosity liquid additives were partially substituted for the solid additives used so far, and secondly, we prepared a solvent mixture that allowed the spraying of high viscosity coatings. In addition to the rheological tests, the coatings themselves were also qualified by flammability and conductivity tests in accordance with the industry requirements established by the PEMÜ. The base polymers to be coated were then selected in accordance with the intended industrial use. In addition to the reference, additive-free base polymers, reference flame retarded base polymers were prepared to serve as a basis for comparison when testing the coated base polymers. Then, the coatings were applied to the reference and reference flame retarded base polymer layers by stepwise layer formation, including brushing and spraying. The adhesion between the coating and the base polymer was qualified by pull-off tests, and the flammability and mechanical testing of the coated polymers was performed

Section 3
1 April 2021 - 31 Marc 2022
BME has optimised the composition of the multifunctional epoxy resin-based gelcoats developed in the second project phase by a systematic series of experiments, taking into account the appropriate viscosity, surface quality, hardness, scratch resistance and effective reduction of the base polymer's flammability. The selected coatings were then sprayed to PP matrix seat belt slider and PUR pipe cover prototypes manufactured by PEMÜ, the coating hardness, scratch resistance and adhesion to the base polymer were characterised and standard flammability tests of the coated prototypes were performed. Based on the cone calorimetric results of the coated prototypes, it was found that the 0.5 mm thick coating containing 15% P from APP formed a foaming protective layer on top of the PP specimen, reduced the maximum heat release rate by 22% and increased the time of it by 54 s compared to the uncoated product. In the case of the PUR prototype, it reduced the maximum heat release rate by 53% and shifted the time of the maximum heat release by 447 s. In addition to a significant reduction in flammability, the coatings significantly increased surface hardness and scratch resistance. An in-situ polymerizable caprolactam based polyamide 6 coating was developed for in-mould coating of long fibre reinforced composites for automotive applications. Several combinations of flame retardants were tested to select those compositions where synergistic flame retardant effects were observed. Patent claims for the protection of the developed coating family have been drafted in cooperation with the PEMÜ, and the Hungarian patent application is pending. An artificial neural network based algorithm has been developed to estimate the high mass demand calorimetric flammability results of non-inhibited and inhibited epoxy resins of known composition based on the chemical structure and low mass demand thermal and flammability measurements.

Section 4
1 April 2022 - 30 September 2022
BME has completed the optimisation of the coated products for both prototypes with epoxy-based gelcoats and composites with in-situ polymerised caprolactam-based flame retardant coatings. In the case of epoxy coatings, gelcoats with optimised viscosity for application can be used to create an "A" quality surface with improved flame retardancy, scratch resistance and hardness, which means that the surface of the finished product does not require any post-processing and can be used as a visible surface in the automotive industry. For crosslinked epoxy resin-based composite products, the maximum heat release of the products has been reduced by 25%, and by at least 50% for thermoplastic prototypes. Bioepoxy coatings have been developed mainly for the thermal protection of metallic structural components. For these coatings, the synergistic effect of flame retardants and inorganic fillers has been exploited to keep the temperaturebelow the sample under 350°C during the one-hour measurement, at which temperature the mechanical properties of the steel do not deteriorate significantly. The heat release of the samples has been reduced by 60% compared to the values measured for the reference coating. For the caprolactam-based coatings, the main objective in the final phase of the project was to compare the performance of in-situ polymerised long-fibre composites produced by composite manufacturing technology, coated in the mould, with that of short-fibre reinforced products produced by compression moulding with core-shell structure. It was found that both in terms of mechanical properties and flame retardancy, caprolactam-based polyamide 6 composites with continuous fiber reinforcement and flame retardant coating are superior. The latter had a maximum heat release half that of the core-shell non-in-situ polymerised systems, which is particularly advantageous for future automotive applications. A Hungarian patent application has been filed with PEMÜ to protect the developed coa



Project-related publications


  1. Kovács Zs., Toldy A.: Synergistic flame retardant coatings for carbon fibre-reinforced polyamide 6 composites based on expandable graphite, red phosphorus, and magnesium oxide. Polymer Degradation and Stability, 222, 110696/1-110696/ (2024) 10.1016/j.polymdegradstab.2024.110696 IF=6.3 D1
  2. Kovács Zs., Toldy A.: Development of flame retardant coatings containing hexaphenoxycyclotriphosphazene and expandable graphite for carbon fibre-reinforced polyamide 6 composites. Polymer Degradation and Stability, 230, 111017 (2024) 10.1016/j.polymdegradstab.2024.111017 IF=6.3 D1
  3. Poór Dániel István, Tobey Marina, Taynton Philip, Pomázi Ákos, Toldy Andrea, Geier Norbert: A comparative machinability analysis of polyimine vitrimer, epoxy and polycarbonate polymers through orthogonal machining experiments. International Journal of Advanced Manufacturing Technology, , s00170-024-13087-9/1-s00170-024-13087-9/16 (2024) 10.1007/s00170-024-13087-9 IF=2.9 Q2
  4. Kovács Zs., Toldy A.: Flame retardant coatings for E-caprolactam-based self-reinforced polyamide 6 composites. in 'ECCM21 – 21st European Conference on Composite Materials Nantes, Franciaország. 2024.07.02.-05.,989-995 (2024)
  5. Kovács Zs., Pomázi Á., Hollósi E., Toldy A.: ε-kaprolaktám alapú égésgátló bevonat fejlesztése szénszál erősítésű poliamid 6 kompozitokhoz. Polimerek, 3, 90-96 (2023)
  6. Pomázi Á., Toldy A.: Predicting the flammability of epoxy resins from their structure and small-scale test results using an artificial neural network model. Journal of Thermal Analysis and Calorimetry, 148, 243–256 (2023) 10.1007/s10973-022-11638-4 IF=3 Q2
  7. Pomázi Á., Krecz M., Toldy A.: The effect of the combined application of solid- and gas-phase flame retardants in epoxy gelcoats on the thermal stability, fire performance and adhesion of coated carbon fibre–reinforced epoxy composites. Journal of Thermal Analysis and Calorimetry, 148, 257-270 (2023) 10.1007/s10973-022-11770-1 IF=3 Q2
  8. Pomázi Á., Krecz M., Toldy A.: Thermal behaviour and fire and mechanical performance of carbon fibre-reinforced epoxy composites coated with flame-retardant epoxy gelcoats. Journal of Thermal Analysis and Calorimetry, 148, 2685–2702 (2023) 10.1007/s10973-022-11710-z IF=3 Q2
  9. Kovács Zs., Pomázi Á., Toldy A.: Development of multifunctional flame-retardant gel coatings for automotive applications. Coatings, 13 (2), 345/1-345/14 (2023) 10.3390/coatings13020345 IF=2.9 Q2
  10. Kovács Zs., Pomázi Á., Toldy A.: Development of flame retardant coatings for E-caprolactam-based polyamide 6 composites. in 'European Conference on Composite Materials (ECCM20) Lausanne, Switzerland. 2022.06.26-2022.06.30.,217-224 (2022)
  11. Nguyen T. T. T., Decsov K. E., Bocz K., Marosi Gy., Szolnoki B.: Development of Intumescent Flame Retardant for Polypropylene: Bio-epoxy Resin Microencapsulated Ammonium-polyphosphate. Periodica Polytechnica-Chemical Engineering, 66(2), 313-324 (2022) 10.3311/PPch.19468 IF=1.3 Q4
  12. Pomázi Á., Krecz M., Toldy A.: The effect of resorcinol bis(diphenyl phosphate) on the flammability and flexibility of flame retarded epoxy gelcoats. in 'European Conference on Composite Materials (ECCM20) Lausanne, Svájc. 2022.06.26-30.,67-74 (2022)
  13. Kovács Zs., Pomázi Á., Toldy A.: The flame retardancy of polyamide 6—prepared by in situ polymerisation of ε-caprolactam—for T-RTM applications. Polymer Degradation and Stability, , 109797/1-109797/17 (2022) 10.1016/j.polymdegradstab.2021.109797 IF=5.9 D1
  14. Aljamal A., Szolnoki B., Marosi G.: Flame retardancy of a fully waterborne sugar-based epoxy system. in 'European Meeting of Fire Retardant Polymeric Materials 2021 (FRPM21) Budapest, Magyarország. 2021.08.29-2021.09.01,108-109 (2021)
  15. Temesi T.: Joining of aluminium and flame-retarded polyamid by laser beam. in 'European Meeting of Fire Retardant Polymeric Materials 2021 (FRPM21) Budapest, Magyarország. 2021.08.29-2021.09.01.,171-172 (2021)
  16. Aljamal A., Szolnoki B., Marosi G.: Improving thermal and flame retardant properties of sorbitol based bioepoxy by phosphorus-based flame retardants. in 'European Meeting of Fire Retardant Polymeric Materials 2021 (FRPM21) Budapest, Magyarország. 2021.08.29-2021.09.01,184-185 (2021)
  17. Nguyen T. T. T., Decsov K. E., Szolnoki B., Bocz K., Marosi G.: Synthesis and characterization of new intumescent flame retardant additives in polypropylene . in 'European Meeting of Fire Retardant Polymeric Materials 2021 (FRPM21) Budapest, Magyarország. 2021.08.29-2021.09.01,196-197 (2021)
  18. Pomázi Á., Toldy A.: Development of fire retardant epoxy-based gelcoats for carbon fibre reinforced epoxy resin composites. Progress in Organic Coatings , 151, 106015/1-106015/12 (2021) 10.1016/j.porgcoat.2020.106015 IF=6.206 D1
  19. Toldy A., Kovács Zs., Pomázi Á.: Development of fire retardant epoxy-based gelcoats for carbon fibre reinforced epoxy resin composites . in 'European Meeting of Fire Retardant Polymeric Materials 2021 (FRPM21) Budapest, Magyarország. 2021.08.29-2021.09.01,136-137 (2021)
  20. Pomázi Á., Toldy A.: Predicting the flammability of epoxy resins from their structure and small-scale test results using an artificial neural network model. in 'European Meeting of Fire Retardant Polymeric Materials 2021 (FRPM21) Budapest, Magyarország. 2021.08.29-2021.09.01,112-113 (2021)
  21. Toldy A.: Recyclable-by-design thermoset polymers and composites.
  22. Szolnoki B., Hatoss B., Hollósi E., Nagy S., Marosi G.: Flame retardant rigid polyurethane foams for automotive application . in 'European Meeting of Fire Retardant Polymeric Materials 2021 (FRPM21) Budapest, Magyarország. 2021.08.29-2021.09.01.,134-135 (2021)
  23. Toldy A., Pomázi Á., Szolnoki B.: The effect of manufacturing technologies on the flame retardancy of carbon fibre reinforced epoxy resin composites. Polymer Degradation and Stability, 174, 109094/1-109094/10 (2020) 10.1016/j.polymdegradstab.2020.109094 IF=5.03 Q1
  24. Pomázi Á., Toldy A.: Effect of flame retardant filtration on the fire performance of carbon fibre reinforced epoxy composites made by resin transfer moulding. in 'International Conference on Composite Materials (ICCM22) Melbourne, Australia. 2019.08.11-2019.08.16.,1-12 (2019)
  25. Toldy A., Pomázi Á., Szolnoki B.: The effect of manufacturing technologies on the flame retardancy of carbon fibre reinforced epoxy resin composites. in 'European Meeting on Fire Retardancy and Protection of Materials (FRPM19) Turku, Finland. 2019.06.26-28.,2 (2019)

© 2014 BME Department of Polymer Engineering - Created by: Dr. Romhány Gábor