MTA-BME Research Group

The development of increased energy absorption foam structures

Project ID:
Supported by:
Nemzeti Kutatási, Fejlesztési és Innovációs Hivatal (NKFIH)
1 December 2019 - 30 November 2023
Supervisor (BME):
Prof. Dr. Tibor Czigány
Dr. Ákos Kmetty
Participant researchers (BME):
Tomin Márton
Dr. Tamás-Bényei Péter
Dr. Litauszki Katalin
Gere Dániel

Project summary

The goal of the project is to develop polymer foam structures and analyze their energy absorption mechanism. We will pay special attention to the relationships between the structure and energy absorption capability of single-layer and multi-layer polymer foam structures—this will be examined with the use of non-biodegradable polymer foams and new, biodegradable polymer foams. These results are indispensable for the engineering application of foamed polymer products, such as energy absorption covers in vehicles, packaging of household appliances, and protective gear for martial arts and other fighting sports. The safety of passengers is of paramount importance in vehicles, as is the safety of people outside the vehicle. This is especially true for autonomous cars. Similarly, the safety of athletes, avoiding injury is also very important, that is why various foam structures are used in many areas in protective gear, or for a surface where sports activity can be safely done. Since currently it is difficult to recycle foams made up of several layers of different thermoplastic layers, we will analyze the possibility of recycling the different layers together. Since environmental directives are getting stricter and stricter, the biopolymer foam we plan to develop may provide a good alternative to currently used non-biodegradable foams.

Project results

Section 1
1 December 2019 - 30 November 2020
In the first research period, we performed complex mechanical, microscopic, and morphological tests on different cross-linked polyethylene (X-PE), ethylene-vinyl-acetate copolymer (EVA) and polyurethane (rebonded PUR) foam sheets of various types, thicknesses and densities. Based on compression set tests, we showed the effect of cell structure (average cell size, cell wall thickness) on the recovery capability of polymer foams. We also showed that closed-cell and open-cell foams react differently to compression. Our research on the complex characterization of XPE foams showed that the relationship between density and mechanical properties (compressive strength, energy absorption, shock absorbance, and recovery capability) can be approximated well with the power law. Based on several falling weight impact tests performed with different parameters (impact energy, impactor geometry, impact velocity), we concluded that repeated impacts impair the dynamic properties of foams but this deterioration of properties depends on foam type. Closed-cell foams are more resistant in terms of energy absorption, while open-cell foams are more resistant in terms of impact damping. With scanning electron microscopy, we showed that the reduction in impact damping in the case of microcellular EVA foams comes from the viscoelastic, time-dependent properties of polymers and can be attributed to delayed elastic deformation. In contrast, the cell structure of macrocellular XPE foams suffers permanent, irreversible deformation. We have started the production, testing, and evaluation of biopolymer-based foams. We produced foam structures using different types of polylactic acid (PLA) at different processing temperatures. We investigated exothermic and various endothermic chemical foaming agents and the effect of foaming agent content on cell structure and foam density.
Results of falling weight impact tests: the dependence of absorbed energy, maximum force, maximum deformation, and contact time on density in the case of a 30 mm thick XPE foam

Section 2
1 December 2020 - 30 November 2021

Section 3
1 December 2021 - 30 November 2022

Section 4
1 December 2022 - 30 November 2023

Project-related publications

  1. Bocz K., Ronkay F., Molnár B., Vadas D., Gyürkés M., Gere D., Marosi Gy., Czigány T.: Recycled PET foaming: supercritical carbon dioxide assisted extrusion with real-time quality monitoring. Advanced Industrial and Engineering Polymer Research, 4, 178-186 (2021) 10.1016/j.aiepr.2021.03.002
  2. Litauszki K., Kmetty Á.: Investigation of the damping properties of polylactic acid-based syntactic foam structures. Polymer Testing, 103, 107347 (2021) 10.1016/j.polymertesting.2021.107347 IF=4.282 Q1
  3. Tomin M., Kmetty Á.: Polymer foams as advanced energy absorbing materials for sports applications—A review. Journal of Applied Polymer Science, 139, 1-23 (2021) 10.1002/app.51714 IF=3.125 Q2
  4. Tomin M., Kmetty Á.: Különböző típusú sportszőnyegek csúszási ellenálló képességének vizsgálata. in 'XII. Roncsolásmentes Anyagvizsgáló Konferencia és Kiállítás és 10. Anyagvizsgálat a Gyakorlatban K. Online. 2021.03.17-19,1-10 (2021)
  5. Béky Cs., Tomin M., Kmetty Á.: Termoplasztikus elasztomerek és habosításuk- áttekintés. Polimerek, 7, 27-32 (2021)
  6. Morlin B., Litauszki K., Petrény R., Kmetty Á., Mészáros L.: Characterization of polylactic acid-based nanocomposite foams with supercritical CO2. Measurement, 178, 109385/1-109385/6 (2021) 10.1016/j.measurement.2021.109385 IF=3.927 Q1
  7. Peter T., Litauszki K., Kmetty Á.: Improving the heat deflection temperature of poly(lactic acid) foams by annealing. Polymer Degradation and Stability, 190, 109646 (2021) 10.1016/j.polymdegradstab.2021.109646 IF=5.03 Q1
  8. Litauszki K., Kmetty Á.: Tejsav oligomerrel lágyított, politejsav-alapú biopolimer habok előállítása. Acta Materialia Transylvanica, 4, 32-37. (2021) 10.33923/amt-2021-01-06
  9. Kmetty Á., Tomin M., Bárány T., Czigány T.: Static and dynamic mechanical characterization of cross-linked polyethylene foams: The effect of density. Express Polymer Letters, 14, 503–509 (2020) IF=4.161 Q1
  10. Litauszki K., Kmetty Á.: Characterization of chemically foamed poly(lactic acid). IOP Conference Series: Materials Science and Engineering, 903, 012018/1-012018/1-7 (2020) 10.1088/1757-899X/903/1/012018
  11. Tomin M., Kmetty Á.: Investigation of the energy absorption properties of cross-linked polyethylene foams . IOP Conference Series: Materials Science and Engineering, 903, 012059/1-012059/ (2020) 10.1088/1757-899X/903/1/012059
  12. Tomin M., Kmetty Á.: Evaluating the cell structure‐impact damping relation of cross‐linked polyethylene foams by falling weight impact tests. Journal of Applied Polymer Science, e4999, 1-12 (2020) 10.1002/app.49999 IF=3.125 Q2
  13. Tomin M., Kmetty Á.: Ejtődárdás mérési konstrukció továbbfejlesztése polimer habok dinamikus mechanikai vizsgálatához. Gép, LXXI., 73-76 (2020)
  14. Litauszki K., Kmetty Á.: Politejsav kémiai habképzésének lehetőségei exoterm és endoterm típusú habképzőszerek alkalmazásával. Polimerek, 6, 1138-1142 (2020)
  15. Tomin M., Kmetty Á.: Különböző típusú birkózószőnyegek ütéscsillapítási képességének össze- hasonlítása a sportágban előforduló sportsérülések megelőzése céljából. Magyar Sporttudományi Szemle, 87, 37-38 (2020)

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