In this paper, Acrylonitrile-Butadiene-Styrene matrix composites reinforced with Nano-silica dioxide particles were examined and prepared to study their mechanical properties. The composite sheets were pre-prepared using the hot extrusion process. Due to its wide characteristics, silica dioxide additions can strengthen the usability and mechanical features of composite thermoplastics and polymers. Furthermore, introducing silica dioxide as a filler in various attributes can help to maintain the smooth flow of sufficient powders, reduce caking, and manage viscoelasticity. Despite its advantages, 3D printing generates a significant amount of waste due to limited prints or destroyed support structures. ABS is an ideal material to use because it is a thermoplastic and amorphous polymer with outstanding thermal properties that is also applicable with the FFF (Fused Filament Fabrication) technique. The findings showed that increasing the silica dioxide content reduces the tensile strength to 22.4 MPa at 10 wt%. Toughness, ductility, and yield stress values of ABS/silica dioxide composites at 15 wt% increased, indicating that the composite material reinforced by the silica dioxide particles improved material characteristics. It is essential to consider the impact of recycling in polymer reinforcement with fillers. Furthermore, the improved mechanical qualities of the composite material encourages successful ABS recycling from 3D printing, as well as the possibility of reusing it in a similar application.

The revolution of 3D-printing technology has caused an additional source of plastic waste, especially the new generation of composite filaments that are linked with the commercial fused deposition modeling process, adding pressure to find a sustainable solution to tackle the emerging waste problem. This study aims to investigate the mechanical and thermal properties of a blended recycled composite material produced by mixing two different 3D-printed reinforced composite wastes, carbon fiber CF/nylon, and glass fiber GF/nylon filaments that were mixed at different percentages using a hot extrusion procedure, tested by a tensile testing machine, and processed with five different weight ratios to study the impact of blend ratios on the material characteristics of the recycled composites and to find the optimum weight ratios with the most preferred properties. The results revealed that the maximum tensile strength of the GF/nylon composite was achieved with 60 wt%. The highest elastic modulus value was recorded at 60 wt% GF/nylon. Moreover, it was noted that at 80 wt% of GF/nylon, the ductility is at the peak value among the composites.

The utilization of waste materials like bio-binders and fine aggregates in construction is crucial for achieving environmentally sustainable building practices. By reusing these materials, we can significantly reduce waste production and preserve precious natural resources, making it a vital aspect of sustainable construction. This paper presents the experimental findings on the mechanical characteristics of using micro sand silica mixed with a bio-binder such as okra. The estimated mechanical properties that are discussed in this research include modulus, strength, and toughness. Okra with three different weight percentages (5, 10, and 15%) was mixed with four different micro-size particles (25, 250, 425, and 850 μm) and then compressed into a cylindrical sample. Okra demonstrated good adherence characteristics to sand silica particles, where the test results indicate that adding okra significantly affects the mechanical properties. Thermal analysis and SEM were employed to investigate the material degradation, surface morphology, and the internal structure of the composites. In general, it has been observed that at a particle size of 250 μm, the best mechanical properties have been achieved at a 15% weight ratio of the okra bio-binder.

This study assessed the effect of slicer-made interlocking joints on 3D printed sandwich panels manufactured through fused filament fabrication (FFF) in terms of flexural properties and energy absorption. Composites were prepared with thermoplastic polyurethane (TPU) as the core material and polyamide (PA), polylactic acid (PLA), polyethylene terephthalate (PET) as skin materials for each of the three composites, respectively. In order to assess the implications of internal geometry, 3D printing was done on five infill topologies (Cross-3D, Grid, Gyroid, Line and Honeycomb) at 20% density. All samples had 20% core density and underwent three point bending testing for flexural testing. It was noted that the Grid and Gyroid cores had the best performance in terms of maximum load capacity based on stretch-dominated behavior while Cross-3D and Honeycomb had lower strengths but stable moments during the bending process. Since Cross-3D topology offered the lowest deflection, it was selected for further experiments with slicer added interlocks at the face–core interface. This study revealed the most notable improvements as gains of up to 15% in peak load, 48% in maximum deflection, and 51% in energy absorption compared with the non-interlocked designs. The PET/TPU interlocked demonstrated the best performance in terms of the energy absorption (2.45 J/mm³) and peak load (272.6 N). In contrast, the PA/TPU interlocked exhibited the best flexibility and ductility with a mid-span deformation of 21.34 mm. These results confirm that slicer-generated interlocking interfaces lead to better load capacity and energy dissipation, providing a lightweight, damage-tolerant design approach for additively manufactured sandwich beams.

In construction, incorporating waste materials such as bio-binders and fine aggregates plays a vital role in promoting environmentally friendly building methods. Utilizing these materials for a second time reduces waste generation, contributing to conserving valuable natural resources. This underscores the importance of sustainable construction practices. This study outlines the experimental results concerning the mechanical attributes when employing a combination of micro sand silica and a bio-binder, specifically Abelmoschus esculentus. The investigated mechanical properties in this study encompass modulus, strength, and toughness. The experimentation involved mixing Abelmoschus esculentus with varying weight percentages and three distinct micro-size particles and then compressing them into cylindrical samples. Abelmoschus esculentus demonstrated favorable adhesion properties with sand silica particles, and the findings suggest a noteworthy impact on the mechanical properties upon its addition. Overall, it was observed that the optimal mechanical properties were attained with a 15% weight ratio of Abelmoschus esculentus bio-binder at a particle size of 250 µm.

The rapid growth in the use of carbon fiber-reinforced polymers (CFRPs) and fused-deposition-modeled (FDM) polylactic acid (PLA) has generated substantial non-biodegradable and thermoplastic waste streams, creating urgent needs for scalable recycling and valorization strategies. This study develops and evaluates an integrated route that chemically recovers carbon fibers (CFs) from CFRP waste and converts them into high-performance reinforcements for recycled PLA matrices. CFRP fragments were pre-swollen in acetic acid (120 °C, 1 h), then depolymerized by means of oxidation with 1 M KMnO₄ (100 °C, 2 h), washed, dried (100 °C, 24 h), and size-reduced by means of cryogenic milling. Recycled CFs (treated) and untreated CFRP fragments were blended with 3D-printing PLA waste at 10, 20 and 30 wt.% via melt mixing (175 °C, 5 min, 70 rpm) and molded into ASTM D638 dog-bone specimens. Materials were characterized via XRD, FTIR, Raman, SEM and mechanical testing. XRD and Raman confirmed retention of the graphitic backbone after treatment; FTIR and Raman revealed oxygen-containing surface functionalization consistent with oxidation, while SEM showed effective removal of epoxy and improved fiber surface cleanliness. Compared with neat PLA (tensile strength 45.4 MPa; modulus 2.6 GPa; elongation 6.3%), composites reinforced with chemically recycled CFs exhibited marked mechanical enhancement: at 30 wt.% treated CF, the tensile strength increased to 102.6 MPa (+126%), elastic modulus to 11.7 GPa (+350%), and toughness to 250.3 MPa, while ductility decreased to 2.9%. Equivalent composites with untreated CFRP exhibited smaller gains (30 wt.%: tensile 87.3 MPa; modulus 10.3 GPa), highlighting the benefit of epoxy removal and surface activation for fiber–matrix adhesion. The proposed chemical recycling pathway is operationally simple and cost-effective, produces reusable CFs with preserved graphitic structure and enhanced surface chemistry, and enables the fabrication of high-performance, waste-derived PLA composites suitable for structural and engineering applications. This work demonstrates a viable waste-to-value approach that advances circularity for both CFRP and 3D-printing polymer waste streams.