TY - JOUR AU - Széplaki, Péter AU - Hajagos, Szabolcs AU - Krizsma, Szabolcs Gábor AU - Zink, Béla AU - Suplicz, András TI - Preparation and Analysis of High-Performance Thermoplastic Composites JF - POLYMER COMPOSITES J2 - POLYM COMPOSITE VL - 47 PY - 2026 IS - 2 SP - 1860 EP - 1871 PG - 12 SN - 0272-8397 DO - 10.1002/pc.70258 UR - https://m2.mtmt.hu/api/publication/36289489 ID - 36289489 N1 - First published: 13 August 2025 This work was supported by the National Research, Development and Innovation Office, Hungary (OTKA FK 138501). Project no. RRF-2.3.1-21-2022-00009, titled National Laboratory for Renewable Energy, has been implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of Programme Széchenyi Plan Plus. This research was funded by the Horizon Europe Framework Programme and the call HORIZON-WIDERA-2021-ACCESS-03 under the grant agreement for project 101079051-IPPT_TWINN. Project no. KDP-IKT-2023-900-I1-00000957/0000003 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the KDP-2023 funding scheme. Project no. TKP-6-6/PALY-2021 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme. This paper was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences (MTA). AB - As the plastics industry continues to grow, the amount of plastic waste increases. The European Union is trying to reduce the amount of plastic waste through various actions. Recycling is perhaps the best way to achieve this. The importance of polymer composites has increased dramatically, and thanks to the spread of thermoplastic resin transfer molding (T‐RTM), composites can be produced very efficiently. This is because ɛ‐caprolactam, the monomer of polyamide 6 (PA6), can be processed at low pressures like epoxy or any other thermoset resin due to its low viscosity. PA6 is produced from ɛ‐caprolactam, activator, and catalyst by in situ ring‐opening polymerization in a temperature‐controlled mold with sufficiently short cycle times. We produced carbon fiber–reinforced composite sheets with PA6 as the matrix material by T‐RTM. A special vertical injection molding machine and the corresponding in situ unit were used for the experiments. We investigated the mechanical, thermal, and morphological properties of continuous carbon fiber–reinforced composites—we performed mechanical and thermal tests on the samples and compared the results with the properties of reference sheets produced from the matrix material. Our goal was to produce high‐quality and properly impregnated composite products suitable for engineering applications. Exploring these relationships is essential for creating components with high aesthetic value, which can be used in visible locations in addition to their load‐bearing role. LA - English DB - MTMT ER - TY - JOUR AU - Hajagos, Szabolcs AU - Kovács, József Gábor AU - Suplicz, András AU - Széplaki, Péter AU - Zink, Béla TI - An experimental and theoretical study on the electrical conductivity of polymer composites JF - JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY J2 - J MATER RES TECHN VL - 39 PY - 2025 SP - 6300 EP - 6309 PG - 10 SN - 2238-7854 DO - 10.1016/j.jmrt.2025.10.217 UR - https://m2.mtmt.hu/api/publication/36455717 ID - 36455717 N1 - The research was done under the scope of the Project no. RRF-2.3.1-21-2022-00009, entitled „National Laboratory for Renewable Energy” which has been implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of Programme Széchenyi Plan Plus. Project no. KDP-IKT-2023-900-I1-00000957/0000003 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development, and Innovation Fund, financed under the KDP-2023 funding scheme. This paper was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences (MTA). This research was funded by the Horizon Europe Framework Programme and the call HORIZON-WIDERA-2021-ACCESS-03, under the grant agreement for project 101079051 – IPPT_TWINN. AB - In recent years, hydrogen fuel cells have emerged as one of the most promising green energy sources. Although fuel cells and their manufacturing technologies are still under development, recent research has shown encouraging progress. While polymers are typically known for their excellent electrical insulating properties, incorporating appropriate conductive fillers can transform them into electrically conductive composites. Potential fillers include graphite, graphene, carbon black, and carbon fibers. In this study, we evaluate the effect of filler properties on mechanical properties, and thermal and electrical conductivity in conductive mono-composites. Our results and conclusions can contribute to the development of conductive hybrid polymer composites suitable for fuel cell applications. We prepared composites using carbon black, carbon fiber, and graphite in a polypropylene matrix. We investigated the effects of processing parameters and evaluated the resulting materials' mechanical, thermal, and electrical properties. Among the tested fillers, one type of graphite exhibited superior electrical and thermal conductivity without compromising mechanical performance. Furthermore, we adapted a semi-empirical thermal conductivity model to describe the electrical conductivity of composites above the percolation threshold. The modified model showed high accuracy, offering a practical tool for material design and engineering applications. © © 2025. Published by Elsevier B.V. LA - English DB - MTMT ER - TY - JOUR AU - Krizsma, Szabolcs Gábor AU - Mészáros, László AU - Kovács, Norbert Krisztián AU - Suplicz, András TI - Expanding the applicability of material jetting–printed photopolymer prototype injection moulds by gamma irradiation post-treatment JF - JOURNAL OF MANUFACTURING PROCESSES J2 - J MANUFACT PROCES VL - 134 PY - 2025 SP - 135 EP - 145 PG - 11 SN - 1526-6125 DO - 10.1016/j.jmapro.2024.12.037 UR - https://m2.mtmt.hu/api/publication/35656265 ID - 35656265 N1 - Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest, H-1111, Hungary HUN-REN-BME Research Group for Composite Science and Technology, Műegyetem rkp. 3, Budapest, H-1111, Hungary MTA-BME Lendület Lightweight Polymer Composites Research Group, Műegyetem rkp. 3, Budapest, H-1111, Hungary Export Date: 20 January 2025 Correspondence Address: Mészáros, L.; Department of Polymer Engineering, Műegyetem rkp. 3, Hungary; email: meszaros@pt.bme.hu AB - Additive manufacturing (AM) revolutionized modern production and tooling, as it can help speed up the development process. This is also true for injection moulding. For instance, polymeric low-volume injection moulds are easy to produce by material jetting (MJ) technologies like PolyJet™. The downside of these MJ printed moulds is their relatively low glass transition temperature, which can result in unacceptably low stiffness and increased creep compliance in the operational temperature range. Different post-curing techniques like high-energy irradiation can enhance the degree of cross-linking in MJ-printed photopolymer parts. We applied MJ (PolyJet™ technology) to produce specimens for mechanical and morphological characterizations and low-volume injection moulds. After printing, we subjected the specimens and the inserts to high-energy gamma irradiation with doses of 50 kGy, 100 kGy, 150 kGy and 200 kGy. Dynamic mechanical analysis (DMA) showed the effects of irradiation on material properties: the glass transition temperature of the photopolymer rose by almost 10 °C from 70.8 °C of the untreated insert to 81.6 °C of the specimen irradiated with 200 kGy. The creep time temperature superposition (TTS) tests proved that the increasing irradiation doses significantly reduced creep compliance, which resulted in considerably lower mould insert deformations. Creep compliance measured at 35 °C fell from 1920 μm2/N of the untreated specimen to 518 μm2/N of the specimen irradiated with 200 kGy. After the material tests, we applied an elaborated comprehensive state monitoring system (operational strain, cavity pressure and temperature measurements) to highlight the fundamental effect that the irradiation has on the operational behaviour of the MJ-printed mould inserts. Injection moulding tests showed that the increasing irradiation doses resulted in significantly decreased operational deformations. Maximal operational strain of the mould inserts fell from 1 % measured on the untreated (0 kGy) insert to 0.5 % measured on the insert irradiated with 200 kGy. It is highly desirable because product dimensional accuracy is also increased. Irradiation also significantly increased mould life (the number of products that can be manufactured), which is a crucial advantage from an economic point of view. We proved that post-curing by gamma radiation is a feasible way to enhance the applicability and the dimensional stability of photopolymer injection mould inserts. This is a definitely novel way to enhance the applicability of MJ-printed low-volume injection moulds. LA - English DB - MTMT ER - TY - JOUR AU - Krizsma, Szabolcs Gábor AU - Suplicz, András AU - Gere, Dániel TI - Customised production of injection moulded parts from recycled materials using rapid tooling approach and coupled injection moulding-thermal and mechanical simulation JF - RESULTS IN ENGINEERING J2 - RESULT ENGIN VL - 26 PY - 2025 PG - 15 SN - 2590-1230 DO - 10.1016/j.rineng.2025.105272 UR - https://m2.mtmt.hu/api/publication/36144700 ID - 36144700 N1 - The research was supported by the National Research, Development and Innovation Office, Hungary (OTKA PD146135 and OTKA FK138501). Project no TKP-6–6/PALY-2021 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme. Project no RRF-2.3.1–21–2022–00,009, titled National Laboratory for Renewable Energy has been implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of Programme Széchenyi Plan Plus. The project was funded by the National Research, Development and Innovation Fund of Hungary in the frame of the GINOP_PLUSZ- 2.1.1–21–2022–00,041 project. The research was funded by the Sustainable Development and Technologies National Programme of the Hungarian Academy of Sciences (FFT NP FTA). Dániel Gere is thankful for the János Bolyai Research Scholarship (BO/00,894/23/6) of the Hungarian Academy of Sciences. AB - Additive manufacturing is the state of the art in modern tool making. It makes the low-volume production of polymeric parts and prototype moulds feasible. Injection moulded parts can be customised flexibly and fast with prototype polymeric moulds. Another trend in the plastics industry is the widespread use of recycled materials to reduce environmental impact. In this article, we introduce a novel technological concept: applying prototype injection moulds to process recycled materials. We investigated three materials: original PP, a recycled PP-HDPE mixture, which is a commercially available injection moulding material and a recycled PA6 that is difficult to mould due to the high melt temperature. All three materials were injection moulded successfully with outstanding product quality. The injection moulding process was modelled with a coupled injection moulding simulation—finite element thermal and mechanical simulation. The presented novel modelling method proved accurate. The injection pressure, temperature and strain results of the simulations showed excellent agreements with the measured results. The application of additively manufactured prototype moulds to produce parts from recycled materials is definitely a novelty. LA - English DB - MTMT ER - TY - JOUR AU - Krizsma, Szabolcs Gábor AU - Suplicz, András TI - Novel Coupled Simulation Method and Comprehensive Metrology to Enhance the Application of Prototype Injection Moulds JF - ADVANCES IN SCIENCE AND TECHNOLOGY J2 - ADV SCI TECHNOL VL - 165 PY - 2025 SP - 179 EP - 188 PG - 10 SN - 1662-8969 DO - 10.4028/p-q56eQa UR - https://m2.mtmt.hu/api/publication/36217662 ID - 36217662 AB - Injection moulding is the most diverse and dynamically developing polymer processing technology. Conventional injection moulding is economically viable only in large-volume part production. However, there is an ever-growing demand for more customised, low-volume plastic products, which is called mass customization. This need can be served by the hybridisation of injection moulding with additively manufactured, low-volume injection moulds (produced for example from thermoset resins by PolyJet technology). In our work, we elaborated a novel statemonitoring and modelling method to analyse the mechanical and thermal characteristics (strains and temperature distribution) of these polymeric injection mould inserts during operation. The results of the modelling method were successfully validated by the actual injection moulding experiments, proving the adequacy of the modelling method. © 2025 Trans Tech Publications Ltd, All Rights Reserved. LA - English DB - MTMT ER - TY - CHAP AU - Krizsma, Szabolcs Gábor AU - Suplicz, András ED - Csüllög, Mihály ED - Mankovits, Tamás TI - Novel Coupled Simulation Method and Comprehensive Metrology to Enhance the Application of Prototype Injection Moulds T2 - The 10th International Scientific Conference on Advances in Mechanical Engineering (ISCAME) VL - 165 AST PB - Trans Tech Publications CY - Bäch SN - 9783036406107 PY - 2025 SP - 393 EP - 402 PG - 10 UR - https://m2.mtmt.hu/api/publication/36227425 ID - 36227425 AB - Injection moulding is the most diverse and dynamically developing polymer processing technology. Conventional injection moulding is economically viable only in large-volume part production. However, there is an ever-growing demand for more customised, low-volume plastic products, which is called mass customization. This need can be served by the hybridisation of injection moulding with additively manufactured, low-volume injection moulds (produced for example from thermoset resins by PolyJet technology). In our work, we elaborated a novel statemonitoring and modelling method to analyse the mechanical and thermal characteristics (strains and temperature distribution) of these polymeric injection mould inserts during operation. The results of the modelling method were successfully validated by the actual injection moulding experiments, proving the adequacy of the modelling method. © 2025 Trans Tech Publications Ltd, All Rights Reserved. LA - English DB - MTMT ER - TY - JOUR AU - Krizsma, Szabolcs Gábor AU - Suplicz, András TI - Comparative study of additively manufactured, state-of-the-art photopolymers and their applicability in prototype mould making JF - INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY J2 - INT J ADV MANUFACT TECHNOL VL - 139 PY - 2025 SP - 6187 EP - 6200 PG - 14 SN - 0268-3768 DO - 10.1007/s00170-025-16286-0 UR - https://m2.mtmt.hu/api/publication/36288262 ID - 36288262 N1 - Open access funding provided by Budapest University of Technology and Economics. Project no. RRF-2.3.1–21-2022–00009, titled National Laboratory for Renewable Energy, has been implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of Programme Széchenyi Plan Plus. This research was funded by the Horizon Europe Framework Programme and the call HORIZON-WIDERA-2021-ACCESS-03, under the grant agreement for project 101079051 – IPPT_TWINN. Project no. TKP-6–6/PALY-2021 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme. AB - Additive manufacturing is a state-of-the-art technology widely used for mould making. Material jetting (MJ) is one of the best additive technologies because of the dimensional accuracy and the outstanding mechanical properties of the printed parts. MJ is a high-end additive technology, requiring expensive printers and resins. Because of this, MJ is typically limited to special, technical applications. Another limitation of MJ-printed resins is their low glass transition temperature ( T g ), and the decrease in strength, stiffness and high creep above T g . An important development direction of photopolymer resins is increasing the T g and enhancing resistance against heat. This article presents a thermal post-curing method, which aims to improve the thermomechanical performance of photopolymers. This article presents a comparative study of two commercial resins for injection mould making: DigitalABS and Loctite3955. The mechanical and thermomechanical properties of both resins can be modified after printing by thermal post-curing, which results in higher strength, stiffness and resistance against heat, and reduced creep, which are all beneficial for mould making. Thermomechanical material characterisation was performed first, to prove the effect of thermal post-curing on the temperature-dependent stiffness and creep properties. The temperature dependence of stiffness was measured by dynamic mechanical analysis in temperature sweep mode. Both as-printed resins showed a decrease in stiffness with increasing temperature but Loctite3955 post-cured above 160 °C, causing an increase in stiffness. Thermal post-curing drastically increased the storage modulus of Loctite3955 from 2041 to 3934 MPa at room temperature and the difference remained nearly the same in the 20–160 °C temperature range. Following the successful material tests, we performed injection moulding tests to analyse the effect of thermal post-curing on mould insert deformations. Thermal treatment resulted in a considerably (by more than 80%) reduced deformation of the mould insert made from Loctite3955 compared to DigitalABS. Also, there was no residual deformation on the post-cured Loctite3955 insert in contrast to the DigitalABS inserts, which had considerable deformations. The results presented in this article clearly highlight the beneficial effects of thermal post-treatment on the thermomechanical properties of photopolymer parts. Our findings allow the more widespread use of these photopolymers in applications where signifcant thermal and mechanical loads occur. LA - English DB - MTMT ER - TY - JOUR AU - Krizsma, Szabolcs Gábor AU - Suplicz, András TI - Applying high-performance resins in stereolitography printing to produce prototype injection moulds JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 15 PY - 2025 IS - 1 PG - 13 SN - 2045-2322 DO - 10.1038/s41598-025-23249-8 UR - https://m2.mtmt.hu/api/publication/36433223 ID - 36433223 N1 - Project no. RRF-2.3.1-21-2022-00009, titled National Laboratory for Renewable Energy has been implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of Programme Széchenyi Plan Plus. This research was funded by the Horizon Europe Framework Programme and the call HORIZON-WIDERA-2021-ACCESS-03, under the grant agreement for project 101079051 – IPPT_TWINN. Project no. TKP-6-6/PALY-2021 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme. AB - Additive manufacturing (AM) revolutionised the modern plastics industry. Its flexibility and ability to build almost any complex geometry without the need for conventional tooling or machining is especially desirable. In our article, we analysed two resins which can be processed by vat photopolymerisation: High Temperature and Rigid10K. They are especially recommended for rapid tooling because of their resistance to heat loads, high strength and stiffness. The application of vat photopolymerisation to produce prototype injection moulds is a definite novelty because the international research community has not realised the potential of this AM technology in rapid tooling. We performed dynamic mechanical analysis in temperature sweep and creep time temperature superposition (TTS) modes to determine the temperature-dependent stiffness and creep characteristics of the resins. The storage modulus of the High Temp resin was 2960 MPa at room temperature while it was 4055 MPa for Rigid10K. Their difference in storage modulus gradually diminished as they were heated to 123 °C. Above that, the High Temp resin showed higher modulus. The creep compliance of Rigid10K was considerably lower compared to the High Temp resin until 90 °C but it was excessive above that. After the material tests, two injection mould inserts were printed and post-cured. The inserts were fitted with strain gauges and thermocouples, which measured the operational deformations and the temperature of the inserts during injection moulding. The Rigid10K insert showed nearly an order of magnitude lower maximum deformation than the High Temp insert. The Rigid10K insert endured the injection moulding test while the High Temp insert cracked. The results proved that both resins are applicable in prototype injection mould making, but the durability of the Rigid10K insert is considerably better. LA - English DB - MTMT ER - TY - JOUR AU - Krizsma, Szabolcs Gábor AU - Kiss, Lóránt AU - Suplicz, András AU - Homlok, Renáta AU - Mészáros, László TI - Gamma-irradiation post-treatment in photopolymer-based additive manufacturing: An efficient method for improved performance JF - MATERIALS TODAY COMMUNICATIONS J2 - MATER TODAY COMMUN VL - 49 PY - 2025 PG - 9 SN - 2352-4928 DO - 10.1016/j.mtcomm.2025.114205 UR - https://m2.mtmt.hu/api/publication/36455001 ID - 36455001 N1 - Funding Agency and Grant Number: Ministry of Culture and Innovation of Hungary [NKKP ADVANCED 149578, RRF-2.3.1-21-2022-00009]; Recovery and Resilience Facility of the European Union; Horizon Europe Framework Programme; International Atomic Energy Agency (IAEA); National Research, Development and Innovation Office, Hungary [OTKA FK138501]; [HORIZON-WIDERA-2021-ACCESS-03]; [101079051 - IPPT_TWINN]; [F23036] Funding text: The authors acknowledge the Ministry of Culture and Innovation of Hungary for support from the National Research, Development and Innovation Fund through Grant no. NKKP ADVANCED 149578. Project no. RRF-2.3.1-21-2022-00009, titled National Laboratory for Renewable Energy has been implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of Programme Szechenyi Plan Plus. This research was funded by the Horizon Europe Framework Programme and the Call HORIZON-WIDERA-2021-ACCESS-03, under the grant agreement for Project 101079051 - IPPT_TWINN. The authors also extend their acknowledgment to the International Atomic Energy Agency (IAEA) for financial support under the umbrella of CRP (Coordinated Research Project, F23036) . This work was supported by the National Research, Development and Innovation Office, Hungary (OTKA FK138501) . AB - Material-jetting is a sub-field of additive manufacturing that typically produces cross-linked products with high engineering value. Various post-treatment techniques are often used to enhance the performance of the product. The aim of these post-treatments is mainly to increase the cross-linking density. The use of ionising radiation can be an excellent alternative for this purpose. In this study, gamma radiation was chosen as the ionising radiation and its applicability as a post-treatment technique was investigated. The printed samples were post-treated with absorbed doses between 25 and 200 kGy. Irradiation has significantly changed the mechanical properties. The tensile modulus for the untreated sample (0 kGy) was 1.92 GPa and it increased to 2.76 GPa after irradiation with 200 kGy, while the tensile strength increased from 38.1 MPa to 64.6 MPa. The heat deflection temperature of the untreated specimen was 48 degrees C, which increased to 60 degrees C for the 200 kGy irradiated specimen. The irradiation also had an effect on the thermal properties: the glass transition temperature increased from 46.7 degrees C to 59.6 degrees C, which is an outstanding result when compared to other post-treatment techniques. The changes in properties were caused by an increase in cross-link density, as confirmed by swelling and Fourier transform infrared spectroscopic analyses. The results presented in this study prove that high-energy gamma irradiation is a novel and effective tool to customise the mechanical and thermal properties of material jetting printed photopolymer parts. Gamma irradiation has clear practical benefits in industries where it is already applied, like medical device manufacturing, pharmaceutical or food industry, where strict sterilisation requirements can often be fulfilled by it. LA - English DB - MTMT ER - TY - CONF AU - Lorber, Rebeka AU - Zink, Béla AU - Suplicz, András AU - Krizsma, Szabolcs Gábor AU - Széplaki, Péter AU - Haar, Bernd AU - Lechner, Bernhard AU - Verčkovnik, Marko AU - Dobnik, Jure ED - Nardin, Blaž ED - Lorber, Rebeka ED - Slapnik, Janez TI - Overmoulding Strength of PP and ABS Systems: Influence of Tool and Melt Temperatures T2 - Metal replacement and lightweight polymer composites : 3rd IPPT_TWINN conference PB - Faculty of Polymer Technology C1 - Slovenj Gradec SN - 9789616792172 PY - 2025 SP - 22 EP - 22 PG - 1 UR - https://m2.mtmt.hu/api/publication/36344317 ID - 36344317 LA - English DB - MTMT ER -