Electromagnetic radiation can have a negative effect on electronic circuits, for example, by disrupting their work and communication. Therefore, there is a need to reduce or eliminate electromagnetic interference using shields. This paper focuses on using waste materials in the form of iron scale, which is easy and inexpensive to obtain for shielding. Iron scale is the result of gaseous or aqueous corrosion, due to which a superficial layer of metal oxides formed on the surface of heated metal objects as a result of their contact with air or water during an industrial process is developed. In this study, morphology, chemical, and phase composition measurements were carried out. The results show that all the iron-based materials investigated are mainly composed of iron oxides and pure iron. The polymer–iron composites with different quantitative and qualitative compositions were prepared to verify the shielding effectiveness. The electrical resistance, impact strength, and magnetic properties were measured, and dynamic mechanical thermal analysis and tensile strength tests were performed. The tests confirmed the suitability of iron scale for the construction of electromagnetic field shielding material. Iron scale is cheap and easy to obtain from iron-based waste materials. The developed composites are easy to form and use recycled material.

The paper undertakes preliminary research towards the identification of the use of plastic waste, taking into account the possibility of increasing their mechanical strength and reducing flammability, as well as reducing the emission of harmful compounds to the atmosphere through the addition of cement. This is extremely important not only from the point of view of the wide use of plastic products in the industry, but also their thermal utilization. The present study deals with the aspect of the utilization of waste polyethylene (HDPE) as a matrix in composites with filler in the form of cement at 5 and 10%. The composite samples were prepared by injection molding after the prior proper mixing of the components. Comparative thermomechanical (DSC, tensile strength, DMTA), microstructure and flammability results are presented for HDPE samples and their composites with cement. It was found that the addition of cement as a filler to polyethylene made it possible to obtain composites with good thermomechanical properties.

This study examines the influence of scale effects on the thermomechanical and structural performance of chemically cured, glass-fibre-reinforced polyester composites. Two reinforcement architectures—plain 0/90° fabric and biaxial fabric—were analysed to assess differences in resin flow, curing behaviour, and mechanical characteristics. Differential Scanning Calorimetry (DSC) was employed to characterise cross-linking kinetics at 15 °C, 19 °C, and 25 °C, demonstrating that higher cure temperatures markedly accelerate gelation and cross-linking. Composite plates were manufactured by Light Resin Transfer Moulding (L-RTM), and static tensile tests were conducted in accordance with PN-EN ISO 527-4. The results confirm that reinforcement architecture strongly affects processability and mechanical performance. The 0/90° fabric provided superior resin permeability and shorter infusion times, whereas the biaxial fabric required higher injection pressure and exhibited longer curing duration. Statistical analysis based on Weibull’s brittle strength theory verified the presence of scale effects: larger specimens displayed lower nominal strength due to a higher probability of internal flaws. Multiple regression modelling further revealed relationships between geometric and mechanical parameters: maximum (destructive) stress, Rm, was the dominant factor influencing both specimen thickness and number of layers, while deformation at maximum stress (εm) primarily determined specimen length. These findings highlight the necessity of accounting for size-dependent behaviour when designing and testing polymer composites. Considering scale effects enables more reliable extrapolation from laboratory-scale tests to full-scale components, thereby improving predictability and structural reliability in engineering applications.

The article presents the results of the simulation of the shielding effectiveness of composites with a single-layer and double-layer structure. The layer parameters are based on the actual properties of the waste materials such as scale and nanocrystalline tapes. The use of waste materials indicates the pro-ecological nature of such a solution, as it allows to reduce the consumption of raw materials and energy as well as real savings in obtaining material.

Znaczącym osiągnięciem ostatnich 50 lat jest rozwój badań nad wytwarzaniem wysokiej jakości materiałów kompozytowych. Z definicji klasyczne kompozyty to materiały będące kombinacją co najmniej dwóch składników (faz), np. cząstki, włókna, tkaniny w matrycy polimerowej, metalowej lub ceramicznej. Kompozyty wykazują wiele unikatowych właściwości w porównaniu z litymi materiałami metalowymi i ceramicznymi, a także czystymi polimerami i kopolimerami. Dotyczy to zwłaszcza stosunku ich sztywności i wytrzymałości do masy (wytrzymałość i sztywność właściwa). Właściwości kompozytów zależą w dużej mierze od wielkości, kształtu i postaci włókien i cząstek je wypełniających, w szczególności w przypadku ich dużego udziału w objętości kompozytu. Dotyczy to również materiałów kompozytowych wytwarzanych dla przemysłu elektronicznego i elektrotechnicznego, gdzie oprócz odpowiednich właściwości mechanicznych wymagane są odpowiednie właściwości elektryczne, m.in. wysoka zdolność ekranowania pola elektromagnetycznego w szerokim zakresie częstotliwości. Badanie właściwości materiałów wykorzystywanych w produkcji kompozytów dla przemysłu elektronicznego i elektrotechnicznego.

The development and miniaturization of electronics and communication technologies brings new challenges related to the generation of high-frequency electromagnetic waves, which can cause interference in the operation of other devices. In the area of interest of researchers and industry, various types of electromagnetic field shielding solutions can be found, including those based on recycled materials. The presented research focused on two methods of screen production, i.e. hot pressing and additive printing, which are among the simplest technologically and economically efficient. A matrix of pulverized high-density polyethylene (HPDE) from recycling was selected for the research, mill scale, crushed nanocrystalline sheet, short carbon fibers and Fe2O3 powder were selected as the filling. Cuboidal samples with dimensions a = 100 mm h = 1 mm were produced from them using both methods, and then the results of shielding effectiveness were compared in the frequency range from 8 GHz to 13 GHz.