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A multi‐stage fiber spreading process for the preparation of high‐performance continuous aramid fiber reinforced nylon 12 (CAF/PA12) composites was proposed in this paper. The effects of spreading rod crown radius, spreading rod axis height and traction speed on fiber impregnation effect and filaments properties were investigated. The fiber volume fraction of the prepared filament was approximately 30%. And the maximum tensile strength and modulus of the filaments were 839.89 MPa and 41.35 GPa, which were 34.36% and 34.30% higher than unspreading filaments, respectively. The influences of printing process parameters such as printing temperature, the combination of layer thickness and printing spacing on the transverse tensile properties of the specimens were studied. Printed specimens reached a transverse tensile strength and tensile modulus of 13.988 MPa and 1.293 GPa, respectively. The influences on low velocity impact properties of the specimens were also investigated in terms of impact energy and printing stacking sequences. Results revealed that the impact threshold energy of orthotropic ([0/90/0/90]2) specimens was 50 J. Quasi‐isotropic ([0/45/90/−45]2) specimens exhibited the superior impact resistance with an impact load of 4.939 kN. Macro‐ and micro‐matrix crack, surface buckling, fiber fracture and delamination were the main failure modes of the specimens. Highlights: A novel thermoplastic composite filament forming process was proposed, and the filament forming equipment was designed and manufactured.Continuous aramid fiber‐reinforced PA12 filaments with about 30% fiber content were prepared by orthogonal tests under different forming process conditions, which showed maximum tensile properties of 839.89 MPa and 41.35 GPa, respectively.Spreading multiplication was positively related to filament tensile properties, which was major affected by the axial height of the spreading rod.Transverse tensile strength (13.988 MPa tensile strength and 1.293 GPa tensile modulus) of printed specimens was investigated under different printing parameters.Fiber orientation had a significant effect on the low‐velocity impact properties. Micro‐ and macro‐matrix crack, surface buckling, fiber fracture and delamination were the main failure modes of the low‐velocity impact specimens. [ABSTRACT FROM AUTHOR]

Continuous fiber reinforced thermoplastic composites (CFRTP) have been increasingly used in aerospace and rail transport in recent years because of their high strength and light weight. In this paper, the effects of nozzle temperature, printing speed, substrate temperature and layer thickness on the tensile properties and macro/microscopic damage modes of CAF/PA12 printed specimens was systematically investigated. The fiber volume fraction(FVF) of CAF/PA12 filaments was 25.62%. The maximum average tensile strength and tensile modulus of CAF/PA12 printed specimens reached 572.60 MPa and 18.49 GPa, respectively. The results of the cross-sectional analysis indicated that filament toothed fractures and transverse cracks were the main macroscopic failure modes of CAF/PA12 composites. In SEM images, the main microscopic failure modes of CAF/PA12 composite are fiber fracture, fiber pull-out pores and unimpregnated fibers. [ABSTRACT FROM AUTHOR]

The efficient purification of cyclohexane is critical, serving as an essential feedstock to produce resins, nylon fibers and pharmaceutical intermediates. However, efficient purification remains a challenging task due to the similarity of cyclohexane and benzene molecules in terms of size and boiling point. In this work, we reported on the synergy of pore size and silanols inside an -SVR-type zeolite for the efficient production of ultrapure cyclohexane (benzene <1 ppm) from benzene/cyclohexane mixture. Under ambient conditions, the SSZ-74 zeolite demonstrated the highest mass-based productivity of 14.5 L/kg for ultrapure cyclohexane among several common zeolites with a considerable dynamic selectivity of ~9.5. The separation ability was evaluated through density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations. The unique ordered silanols inside the zeolite frameworks demonstrated strong but reversible interactions with benzene through SiOH...π interactions, as revealed by in situ Fourier Transform infrared (FTIR) spectra. Purification of cyclohexane serves as a feedstock to produce resins, nylon fibers and pharmaceutical intermediates. Here authors combine specific pore sizes with silanols within a zeolite framework to improve the separation of cyclohexane from benzene, addressing the challenge of their molecular size similarity. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights In this study, interleaving electrospun Nylon 6.6 nanofibers in the laminate was utilized to improve interlaminar properties of glass/epoxy composite during punching and as a solution to this issue. In order to do so, virgin and nano modified samples are produced and punched and the results are compared to determine the effect of nanofibers on the damaged area as well as the three‐point bending residual strength (carried out on both penetration and exit sides) of the punched laminate. Furthermore, punch—die clearance was also varied to investigate the range in which the nano modification improves the outcome of the process on the laminated composite. According to results of this study, using of Nylon 6.6 nanofibers between composite layers causes significant decrease in the damaged area up to 50%. Also, in both virgin and nano modified laminates, increasing the punch—die clearance increases the damaged area up to 50% and reduces the residual strength of the laminates up to 17%. In addition, nano modified laminates, the residual strength increased up to 28% and 22% for three‐point bending tests carried out on both punch penetration‐ and exit‐side samples, respectively. This is due to the fact that the punch exit‐side contains more damage compared to the penetration‐side. Toughening glass/epoxy laminates using electrospoon Nylon 6.6 nanofibers. Decreasing the damage area occur in the punching of composite laminates. Decreasing the damage area in punching by decreasing the punch‐die clearance. Increasing the strength of punched laminates by applying nanofibers. [ABSTRACT FROM AUTHOR]

Highlights Interfacial adhesion properties are a key factor affecting the mechanical properties of composites. It is a very effective way to improve the low‐velocity impact resistance of composites by improving the interfacial adhesion properties. To improve the fiber/matrix interfacial adhesion properties of GF/PA6 (glass‐fiber/polyamide 6) composites, polyethyleneimine (PEI) and γ‐aminopropyltriethoxysilane (KH550) were used to co‐modify GF together in this study. The GF/PA6 composites with different modifications of glass‐fiber (GF) were also prepared using a hot pressing process, and then their flexural strength, shear strength, pendulum impact strength, and low‐speed impact resistance were investigated. Next, the relationship between fiber/matrix interfacial adhesion and mechanical properties of GF/PA6 composites was investigated by combining x‐ray photoelectron spectroscopy, scanning electron microscopy, and x‐ray computed tomography test results. The results showed that the GF‐reinforced PA6 matrix composite with co‐modified GF by PEI and KH550 (PEI‐KH550‐GF/PA6) had the best mechanical properties, with flexural, shear, and pendulum impact strengths of 660.7 MPa, 53.1 MPa, and 261.6 kJ/m2, respectively. Furthermore, the low‐velocity impact resistance was measured in terms of stress peak, absorbed energy, residual stress, and damage extension, and the results showed that the low‐speed impact resistance of PEI‐KH550‐GF/PA6 composites was also substantially improved that the Fmax increased from 7402.1 to 10414.0 N. Due to the poor surface activity of GF, in this experiment, GF was co‐modified with PEI and KH550 to achieve better fiber/matrix interfacial adhesion and successfully improve the mechanical properties of the composites; Different modification methods are used to improve the interfacial adhesion of the fiber/matrix interface. The relationship between the interface and impact strength of composites has been studied; The relationship between fiber/matrix interfacial adhesion and internal cracking in composites was investigated using X‐CT and SEM and other test results. [ABSTRACT FROM AUTHOR]

This study presents a novel variable thickness nested tube consisting of circular tube and origami tube (VTCO) designed to reduce the initial peak crushing force (PCF) under axial loading while maintaining high energy absorption. The core of this design is to achieve progressive and controlled energy absorption and to reduce peak forces as well as accelerations that can lead to passenger injuries. Nested tube structures were fabricated using short carbon fiber‐reinforced nylon composites through 3D printing technology, and quasi‐static axial compression tests were performed. The results show that equal‐thickness nested tubes consisting of circular tubes and origami tubes (ETCO) perform better in terms of energy absorption and deformation stability compared to circular and origami tubes individually. The further improved VTCO reduced the PCF by 53% and significantly improved the crash force efficiency (CFE) by 54%. The VTCO structure was parametrically investigated by means of a validated finite element model and optimized using the Non‐Symmetric Dominance Sorting Genetic Algorithm II (NSGA‐II). The optimization results provide a feasible way to adjust the structural crashworthiness to meet different engineering requirements. This study provides valuable insights into the energy‐absorbing properties of VTCO structures and is an important guide for the application and material development of novel VTCO structures. Highlights: ETCO offers better energy absorption and stability than circular and origami tubes individually.VTCO is superior to ETCO in reducing PCF and increasing CFE.Multi‐objective optimization using NSGA‐II to balance conflicting crashworthiness indicators. [ABSTRACT FROM AUTHOR]

The hot dip aluminized ASTM 1035 steels (Al‐coated steel) underwent anodic oxidization, and various thicknesses of Al2O3 coating were applied to the surface of the Al‐coated steels (Al–Al2O3‐coated steel). The corrosion resistance of the Al–Al2O3‐coated steel was investigated using potentiodynamic tests, electrochemical impedance spectroscopy tests and measurement of galvanic current density in a bimetallic cell. It was found that the anodic oxidation resulted in the formation of a porous Al2O3 coating on the surface of the Al‐coated steel, improving both its corrosion resistance and galvanic corrosion resistance when coupled with carbon fiber reinforced nylon 6 composite (Cf/PA6). Silane treatment effectively sealed the pores within the Al2O3 coating, resulting in improved corrosion protection for Al–Al2O3‐coated steel due to the exceptional insulation, impermeability and hydrophobic properties of silane coating. Compared to the Al‐coated steel/carbon fiber reinforced polymer (CFRP) couple and Al–Al2O3‐coated steel/CFRP couple, stable galvanic current density decreased by approximately 75% and 45%, respectively. [ABSTRACT FROM AUTHOR]

AbstractThe environmental consequences of Portland cement (PC) manufacturing have prompted the exploration of alternative binders, such as the alkali activation of blast furnace slag (BFS), which is generated as a byproduct during the extraction of iron. While alkali-activated blast furnace slag (AAS) binders have some benefits over regular PC binders, they also suffer from disadvantages such as significant drying shrinkage. The study investigated the impact of Na dosage and curing conditions on alkali-activated blast furnace slag mortar (AASM). The consistency of the specimens was tested for fresh, hardened properties, and was conducted. The optimum Na dosage and curing conditions were selected. In the second stage, 0.1% and 0.2% glass and nylon fibers were added to the selected optimum mortar. Consistency, fresh, mechanical, and durability properties tests were conducted on the fiber mortars. The results showed that increasing the Na content increased the compressive and flexural strengths of AASM specimens. Thermal curing provided high compressive and flexural strengths, whereas fiber addition reduced water absorption and drying shrinkage. The drying shrinkage value was reduced by 26.82 % for AASM specimens with 0.2 % nylon fibers by volume compared to AASM without fibers. [ABSTRACT FROM AUTHOR]

Background: Natural product active ingredients are currently being studied rigorously worldwide and offer a viable substitute for traditional immunotherapy for various medical disorders. Aim: The objective of the study was to investigate the immunostimulatory properties of fucoidan in albino Wistar rats. Methods: For the current study, forty rats were divided into five groups of rats that were used in good condition. In-vivo experiments of fucoidan were carried out in Wistar albino rats, such as the cyclophosphamide-caused myelosuppression, the delayed-type hypersensitivity (DTH) response, the phagocytic activity, the haemagglutinating antibody (HA) titer, and the neutrophil adhesion test. Results: The phagocytic index increased significantly in response to Fucoidan in a dose-dependent manner, as well as enhanced DTH reaction, and HA titer caused by sheep red blood cells sheep red blood cells. Additionally, fucoidan decreased myelosuppression in rats after cyclophosphamide treatment and enhanced neutrophil adhesion with nylon fiber. Conclusion: These findings imply that fucoidan has immunostimulant properties and could potentially utilised to treat immune-depression diseases. [ABSTRACT FROM AUTHOR]

In the present study, nylon waste fibers (NWF) were utilized for the first time to improve the impact resistance of self-compacting concrete (SCC) slabs against pistol shooting. Six ratios of NWF were used in the range of (0.25- 1.5 at an increment of 0.25) % with three different lengths (50, 70, and 90) mm for each ratio. The fresh properties, compressive strength, and Utara sonic pulse velocity (UPV) of SCC were also measured. The results indicate the positive role of NWF in improving compressive strength. However, the fresh properties are affected negatively by using NWF. The best impact resistance of the slab occurred when 1% of NWF with a length of 90 mm was utilized. [ABSTRACT FROM AUTHOR]

Thermoplastic composite organosheets (OSs) are increasingly recognized as a viable solution for automotive and aerospace structures, offering a range of benefits including cost-effectiveness through high-rate production, lightweight design, impact resistance, formability, and recyclability. This study examines the impact response, post-impact strength evaluation, and hot-pressing repair effectiveness of woven glass fiber nylon composite OSs across varying impact energy levels. Experimental investigations involved subjecting composite specimens to impact at varying energy levels using a drop-tower test rig, followed by compression-after-impact (CAI) tests. The results underscore the exceptional damage tolerance and improved residual compressive strength of the OSs compared to traditional thermoset composites. This enhancement was primarily attributed to the matrix's ductility, which mitigated transverse crack propagation and significantly increased the amount of absorbed energy. To mitigate impact-induced damage, a localized hot-pressing repair approach was developed. This allowed to restore the post-impact strength of the OSs to pristine levels for impact energies below 40 J and by 83.6% for higher impact energies, when OS perforation was observed. The measured levels of post-repair strength demonstrate a successful restoration of OS strength over a wide range of impact energies, and despite limitations in achieving complete strength recovery above 40 J, hot-pressing repair emerges as a promising strategy for ensuring the longevity of thermoplastic composites through repairability. [ABSTRACT FROM AUTHOR]

Fiber‐based products constitute a significant portion of plastic waste and cause environmental damage. In particular, discarded sanitary masks and fishing gear disintegrate into microfiber plastics, posing a significant threat to human health and ecosystems. In this study, we developed robust biodegradable nanocomposite fibers of poly(butylene adipate‐co‐terephthalate) (PBAT)/cellulose nanocrystals (CNCs) (1 and 2 wt%) through dry‐jet wet spinning, by using dimethyl sulfoxide (DMSO) as a common solvent. The control PBAT fibers exhibit remarkable mechanical performance with tensile strength and toughness of 160.0 MPa and 43.0 MJ m−3, respectively. CNC addition has a toughening effect with slightly reduced strength but enhanced toughness (148.8 MPa and 69.0 MJ m−3, respectively, for 2 wt% CNC); their mechanical performances are superior to those of previously reported PBAT‐based materials. The remarkable performance of the fibers is attributed to a highly oriented structure with a total draw ratio of 15 after post‐hot drawing. The control and nanocomposite fibers exhibit spot‐like patterns in 2D wide‐angle x‐ray diffraction patterns with Herman's orientation factor of 0.54–0.58. The theoretical Hansen solubility parameter confirmed the poor chemical affinity between the PBAT and CNC. Nonetheless, the rheological characterization revealed that well‐dispersed CNCs with DMSO produced a physical network in the PBAT matrix, resulting in the toughening effect. Such robust nanocomposite fibers consisting of fully biodegradable components are promising alternatives to nondegradable nylon and polyester fibers. Highlights: Robust biodegradable nanocomposite fibers of PBAT and CNC are prepared.Nanocomposite fibers are dry‐jet wet spun using DMSO as a common solvent.PBAT fibers exhibit strength and toughness of 160.0 MPa and 43.0 MJ m−3.2 wt% CNC toughens the PBAT fibers with an enhanced toughness of 69.0 MJ m−3.Rheological results confirm the toughening effect of well‐dispersed CNC in PBAT. [ABSTRACT FROM AUTHOR]

Peat is a highly soft soil that possesses low shear strength due to the presence of organic content and a high amount of moisture content. In the present study, the peat is stabilized to enhance the strength with fly ash with different percentages of 3, 6, 9, 12, and 15% and reinforced with nylon fiber with 0.5, 1.0 and 1.5% to investigate the performance of peat. The strength of fly ash and fiber-treated peat is compared with cement-treated peat. The Compaction, California bearing ratio (CBR), Unconfined compressive strength (UCS) and Unconsolidated Undrained Triaxial (UU Triaxial), Freezing & Thawing (F&T) tests were used for evaluating the strength properties of peat. The UCS value increases to 280 kPa from 60 kPa at 12% of fly ash content, but at 15% cement content it was increased up to 370 kPa. The UCS value of peat stabilized with 12% of fly ash and reinforced with 1% of fiber obtained as 360 kPa. The CBR also increased to 9.3 from 2.5% for stabilized peat (12% fly ash) and reinforced fiber (1%) in soaked condition whereas the CBR value increases up to 9.7% for the case of 15% cement content. It is observed from the freezing and thawing tests, the strength of fly ash stabilized peat-reinforced fiber is decreased by 50%. Whereas the cement-stabilized peat is reducing its strength by 30%. Therefore, 15% of cement can be replaced with 12% of fly ash and 1% of nylon fiber together to make the stabilization effective in normal conditions, but not durable for weathering actions compared to cement-treated peat. The pavement thickness is evaluated from CBR value and observed that the stabilized peat-reinforced fiber significantly affects the thickness of the pavement. [ABSTRACT FROM AUTHOR]

The 3D printing of continuous-fiber composites is currently relevant to engineers and researchers. This study aims to characterize and predict the mechanical properties of Onyx/glass fiber specimens printed using 3D printing. The work assesses the impact of glass fiber printing parameters on the mechanical behavior of printed parts and proposes analytical and numerical methods to predict mechanical properties. A physicochemical analysis was conducted on 3D printed continuous glass fibers. The study also investigated the impact of fiber printing parameters on composite parts. The results indicate that the 3D-printed glass fibers consist of nylon, continuous glass fibers, and voids (porosity), which range from 58% to 63%, 31% to 38%, and 5% to 8%, respectively. Mechanical characterizations indicate that printing fiber layers in blocks results in superior mechanical properties compared to printing alternating layers of glass fibers and Onyx. Additionally, the concentric mode of fiber printing can be challenging if the 'start rotation' parameter is not adjusted correctly. Premature specimen breakage occurred when fiber printing began within their useful length, resulting in a deformation at break that was approximately 34% less, depending on the starting position. The proposed analytical and numerical prediction methods had prediction errors of approximately 7% to 12% and 5% to 7%, respectively. Engineers can use these prediction approaches during the dimensioning phase of 3D printed composite parts. [ABSTRACT FROM AUTHOR]

Fused Deposition Modeling (FDM) is a well-established manufacturing method for producing both prototype and functional components. This study investigates the mechanical properties of FDM components by material and process-related influencing variables. Tensile tests were conducted on seven different materials in their raw filament form, two of which were fiber-reinforced, to analyze their material-related influence. To cover a wide range from standard to advanced materials relevant for load-carrying components as well as their respective variations, polylactic acid (PLA), 30% wood-fiber-reinforced PLA, acrylonitrile butadiene styrene (ABS), polycarbonate (PC), a blend of ABS and PC, Nylon, and 30% glass-fiber-reinforced Nylon were selected. The process-related influencing variables were studied using the following process parameters: layer thickness, nozzle diameter, build orientation, nozzle temperature, infill density and pattern, and raster angle. The first test series revealed that the addition of wood fibers significantly worsened the mechanical behavior of PLA due to the lack of fiber bonding to the matrix and significant pore formation. The polymer blend of ABS and PC only showed improvements in stiffness. Significant strength and stiffness improvements were found by embedding glass fibers in Nylon, despite partially poor fiber–matrix bonding. The materials with the best properties were selected for the process parameter analysis. When examining the impact of layer thickness on part strength, a clear correlation was evident. Smaller layer thicknesses resulted in higher strength, while stiffness did not appear to be affected. Conversely, larger nozzle diameters and lower nozzle temperatures only positively impacted stiffness, with little effect on strength. The part orientation did alter the fracture behavior of the test specimens. Although an on-edge orientation resulted in higher stiffness, it failed at lower stresses. Higher infill densities and infill patterns aligned with the load direction led to the best mechanical results. The raster angle had a significant impact on the behavior of the printed bodies. An alternating raster angle resulted in lower strengths and stiffness compared to a unidirectional raster angle. However, it also caused significant stretching due to the rotation of the beads. [ABSTRACT FROM AUTHOR]

The frontal polymerization (FP) of carbon/epoxy (C/Ep) composites is investigated, considering FP as a viable route for the additive manufacturing (AM) of thermoset composites. Neat epoxy (Ep) resin-, short carbon fiber (SCF)-, and continuous carbon fiber (CCF)-reinforced composites are considered in this study. The evolution of the exothermic reaction temperature, polymerization frontal velocity, degree of cure, microstructures, effects of fiber concentration, fracture surface, and thermal and mechanical properties are investigated. The results show that exothermic reaction temperatures range between 110 °C and 153 °C, while the initial excitation temperatures range from 150 °C to 270 °C. It is observed that a higher fiber content increases cure time and decreases average frontal velocity, particularly in low SCF concentrations. This occurs because resin content, which predominantly drives the exothermic reaction, decreases with increased fiber content. The FP velocities of neat Ep resin- and SCF-reinforced composites are seen to be 0.58 and 0.50 mm/s, respectively. The maximum FP velocity (0.64 mm/s) is observed in CCF/Ep composites. The degree of cure (αc) is observed to be in the range of 70% to 85% in FP-processed composites. Such a range of αc is significantly low in comparison to traditional composites processed through a long cure cycle. The glass transition temperature (Tg) of neat epoxy resin is seen to be approximately 154 °C, and it reduces slightly to a lower value (149 °C) for SCF-reinforced composites. The microstructures show significantly high void contents (12%) and large internal cracks. These internal cracks are initiated due to high thermal residual stress developed during curing for non-uniform temperature distribution. The tensile properties of FP-cured samples are seen to be inferior in comparison to autoclave-processed neat epoxy. This occurs mostly due to the presence of large void contents, internal cracks, and a poor degree of cure. Finally, a highly efficient and controlled FP method is desirable to achieve a defect-free microstructure with improved mechanical and thermal properties. [ABSTRACT FROM AUTHOR]

V‐belts are commonly used to transmit power between two distant pulleys. Therefore, a strong reinforcement for dimensional stability and thermomechanical properties are essential in power transmission belts. The influence of resorcinol formaldehyde resin (RFL) treated nylon short fibers in EPDM peroxide‐cured formulations was investigated, with concentrations ranging from 0 to 30 parts per hundred rubber (phr) in increments of five. The incorporation of nylon short fibers resulted in improved tensile and mechanical properties in EPDM vulcanizates. Specifically, the tensile stress at 100% elongation increased by 177% to (10.8 MPa), and the improvement in tear strength to 16.2% (75.7 N/mm) was observed. Among other functional requirements in a weak rubber like EPDM, enhanced tear strength is significant for its application in power transmission. Substantial reinforcement between the fiber‐elastomer matrix was confirmed via scanning electron microscopy, as evidenced by increased storage modulus (E′). Notably, there were no considerable effects on the curing rate or low‐temperature properties. Significant improvement in heat stability is observed through thermogravimetric analysis. These enhancements in mechanical and thermal properties might play a role in increased durability and performance in actual V‐ribbed belt applications. Highlights: This manuscript describes the effect of treated nylon 66 short fiber on EPDM V‐belt compound.A significant increase in storage modulus, tear strength, and thermal stability.A belt is made using the experimental formulation and it meets the performance requirement.Low fiber content (<15 phr) compounds are unsuitable for dimensional stability.High fiber content (>25 phr) compounds pose processing challenges. [ABSTRACT FROM AUTHOR]

Copyright of Basic Sciences Journal of Textile Universities / Fangzhi Gaoxiao Jichu Kexue Xuebao is the property of Basic Sciences Journal of Textile Universities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aims to evaluate the behavior of self-compacting concrete reinforced with fibers in slabs under static loads. Therefore, the current study was divided into two parts. The first part focused on producing self-compacting concrete reinforced with iron fibers or nylon fibers and studying the mechanical properties that include compressive strength and splitting tensile strength of hardened concrete. The second part of the research was concerned with studying the behavior of slabs under static loads. To achieve these goals, the performance of 11 self-compacting concrete mixes was prepared, examined, and evaluated, including five iron fiber-containing mixtures and five nylon fiber-containing mixtures, with volumetric ratios of 0.2%, 0.3%, 0.4%, 0.5%, and 0.6% for each type, and a reference mixture without the fibers. For this purpose, 66 concrete slabs with dimensions 500 × 500 × 50 mm were poured with quality control samples 33 standard cubes with dimensions 150 × 150 × 150 mm and 33 standard cylinders 300 × 150 mm. The results of the tests showed a significant improvement in the mechanical properties of these mixtures, which include the compressive and tensile strengths, and by reviewing the tests of all the mixtures, it was found that the concrete mixture containing iron fibers or nylon fibers with a ratio of 0.4% by volume is the best in terms of hardened mechanical properties. The behavior of the fiber-reinforced concrete slabs under the influence of a dynamic impact load was also studied and compared, and these results were compared with the reference concrete slabs that were not reinforced with fibers. time starts from the moment of implying the load and ends with the quenching of the slabs, where the displacement curves were drawn under the center of the slab-time, and the results showed an increase in the impact resistance of the slabs (the number of blows required for penetration with the increase of fiber content, where the fibers said the amount of the greatest depth and the quenching time of the concrete slabs). The results showed that concrete slabs reinforced with steel fibers have better dynamic properties than those reinforced with nylon fibers. [ABSTRACT FROM AUTHOR]

Within the scope of this study, the design and testing of a fully demountable high‐performance fiber‐reinforced concrete (FRC) barriers with high resistance to sudden dynamic explosion and impact loadings is investigated. In order to solve such an engineering problem, a special FRC "tongue and groove" blocks are designed in a way that could be constructed by two persons to form barriers of various shapes and sizes by combining them easily. The structures produced with these blocks were produced using a hybrid, special FRC mixture in order to resist various bullets, rocket launchers, and explosion effects to protect the person behind them. Within the scope of this study, the resistance of five different special FRC mixtures with different properties against sudden dynamic blasting effects was determined by comparing and interpreting the acceleration‐time and strain‐time measurements taken from the wall directly. The results obtained from the dynamic blasting tests carried out in the field were compared with the results of the numerical analysis performed using the Ls‐Dyna finite element software. As a result of the study, the barrier structure produced with special FRC, in which hybrid nylon and steel fibers are used as reinforcement, exhibited the most successful results for absorbing the energy caused by the rocket blast loadings. [ABSTRACT FROM AUTHOR]

The demolishing waste generated due to demolishing of the structures has proved difficult to handle due to scarcity of the dumping space particularly in urban areas. It's use in new concrete solves the problem to some extent but developed product differ in properties both at fresh and hardened state. To overcome the deficiency nylon fibers are proposed in this work. The compressive and tensile strength of proposed concrete at hardened state and workability as fresh property of concrete are studied. Conventional and recycled aggregates were used in equal proportion. Nylon fibers of 1 mm diameter and 25 mm length were used from 0.25% to 2% with 0.25% increment in each successive batch were used. Using 1:2:4 mix with water cement ratio equal to 0.5, total of 10 mixes were designed. Workability of each mix was evaluated by slump cone test. Water curing for 28-days was used for five samples in each batch. Compressive and tensile strength were computed from crushing load determined in universal testing machine. Comparison of the results with those of control concrete revealed that 1.5% of nylon fibers along with 50% recycled aggregates produce maximum compressive strength 930.16 (MPa) with 24% more than conventional concrete (24.16 MPa) and 56% more than recycled aggregate concrete (19.27 MPa) without nylon fibers. The tensile strength of the proposed concrete (3.66 MPa) was noticed 22% and 55% higher than the conventional concrete (3.0 MPa) and recycled aggregate concrete (2.36 MPa) at optimum dosage. Hence the impact of optimized doze of the nylon fiber shows improved strength properties of the concrete. [ABSTRACT FROM AUTHOR]

The widespread use of carpets in residential and commercial buildings and their relatively short life span result in large volumes of carpet being landfilled. A potential solution to this problem is the use of post-consumer carpet fibers in concrete. To this end, this paper systematically identifies the common fiber types in a typical post-consumer carpet fiber bale and evaluates their durability under exposure to varying levels of alkalinity. The tensile strengths and toughness of the fibers belonging to the nylon and polyethylene terephthalate (PET) families (the dominant fibers in most post-consumer carpets) are reduced by up to 50% following exposure to extreme alkalinity, the reasons for which are determined using spectroscopic and microscopic evaluations. The chloride ion transport resistance of concretes (~40 MPa strength) containing 2.5% carpet fibers by volume (~25 kg of fibers per cubic meter of concrete) is comparable to that of the control mixture, while mortar mixtures containing the same volume fraction of carpet fibers demonstrate negligible enhancement in expansion and loss of strength when exposed to 1 N NaOH. This study shows that moderate-strength concretes (~40 MPa) for conventional building and infrastructure applications can be proportioned using the chosen volume of carpet fibers without an appreciable loss of performance. Consideration of low volume fractions of carpet fibers in low-to-moderate-strength concretes thus provides a sustainable avenue for the use of these otherwise landfilled materials in construction applications. [ABSTRACT FROM AUTHOR]

Achieving ultra-high tensile strength and exceptional toughness is a longstanding goal for structural materials. However, previous attempts using covalent and non-covalent bonds have failed, leading to the belief that these two properties are mutually exclusive. Consequently, commercial fibers have been forced to compromise between tensile strength and toughness, as seen in the differences between nylon and Kevlar. To address this challenge, we drew inspiration from the disparate tensile strength and toughness of nylon and Kevlar, both of which are polyamide fibers, and developed an innovative approach that combines specific intermolecular disulfide bonds and reversible hydrogen bonds to create ultra-strong and ultra-tough polyamide spider silk fibers. Our resulting Supramolecular polyamide spider silk, which has a maximum molecular weight of 1084 kDa, exhibits high tensile strength (1180 MPa) and extraordinary toughness (433 MJ/m3), surpassing Kevlar's toughness 8-fold. This breakthrough presents a new opportunity for the sustainable development of spider silk as an environmentally friendly alternative to synthetic commercial fibers, as spider silk is composed of amino acids. Future research could explore the use of these techniques and fundamental knowledge to develop other super materials in various mechanical fields, with the potential to improve people's lives in many ways. • By emulating synthetic commercial fibers such as nylon and polyethylene, we have successfully produced supramolecular-weight polyamide spider silk fibers with a molecular weight of 1084 kDa through a unique covalent bond-mediated linear polymerization reaction of spider silk protein molecules. This greatly surpasses the previous record of a maximum molecular weight of 556 kDa. • We obtained supramolecular polyamide spider silk fibers with both high-tensile strength and toughness. The stress at break is 1180 MPa, and the toughness is 8 times that of kevlar, reaching 433 MJ/m3. • Our results challenge the notion that it is impossible to manufacture fibers with both ultra-high tensile strength and ultra-toughness, and provide theoretical guidance for developing environmentally friendly and sustainable structural materials that meet industrial needs. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper presents the development and characterization of cost-effective short Kevlar fiber reinforced nylon composite filaments. The effect of Kevlar fiber content on the tensile properties and the fiber distribution morphology was explored. A small amount of short Kevlar fiber was twin-screw compounded with nylon to study the reinforcing effects. Optical microscopy was used to investigate the morphology and the fiber distribution in the nylon matrix. The tensile strength of Kevlar composites increased to 90 MPa and 99 MPa at the fiber content of 1 wt% and 3 wt%, respectively, compared with the tensile strength of 84 MPa for pure nylon. As the fiber content increased from 0 to 3 wt%, the tensile modulus increased from 3.28 to 3.77 GPa. The optical microscopy and SEM images indicate that the twin-screw compounder with a proper screw configuration could disperse and distribute the Kevlar fibers uniformly in the nylon matrix. Statistically, this study demonstrates that the tensile strength and tensile modulus of nylon filament can be effectively enhanced with the addition of small amount of Kevlar fiber (i.e., less than 3 wt%), without sacrificing the ductility. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the physical properties of yarns made with different blend ratios of meta-aramid, para-aramid, flame-resistant (FR) viscose, and antistatic nylon fibers, as well as the tensile strengths and burning behaviors of fabrics made from these yarns. For this purpose, 10 different yarns of two different linear densities were produced using five different blend ratios, which are commonly used in the production of fire-resistant fabrics, and knitted fabrics were produced from these yarns, with the same knitting machine and the same production parameters. Physical properties of the yarns and tensile properties and burning characteristics of the knitted fabrics were measured according to commonly applied standards, and the results obtained were evaluated using the SPSS statistical program. The findings of this study are that the blend ratios of meta-aramid, para-aramid, FR viscose, and antistatic nylon fibers have statistically significant effects on the unevenness, humidity, and tenacity of the yarns, as well as on the tensile properties and burning characteristics of the fabrics. It was found that, with an increase of the aramid fiber ratio in the blend, the tensile values of the yarns and fabrics increased. The lowest moisture contents were recorded for 100% para-aramid yarns but the highest moisture contents were recorded for yarns whose blends contained FR viscose fibers. The yarns whose blends contained antistatic nylon fibers exhibited the greatest unevenness and the most thin and thick places and neps. [ABSTRACT FROM AUTHOR]

Considering the toxicity of traditional resorcinol‐formaldehyde‐latex (RFL) dipping solution used to prepare fiber‐ reinforced rubber composites, a novel eco‐friendly dopamine (DA)‐supported dipping system was developed in this study. Based on the interactions between DA, glycerol triglycidyl ether (GTE), and m‐xylylenediamine (MXDA), the dipping solution successfully coated the surface of the nylon‐66 (PA66), and the resulting GTE/DA/MXDA/latex‐treated PA66 (PA66‐GDML) possessed better thermal stability than untreated PA66. The interfacial adhesion between PA66 and neoprene was significantly improved by using the appropriate interfacial layer and the synergistic effect during co‐vulcanization. The adhesive strength between PA66‐GDML and neoprene was comparable to that obtained in an RFL system, especially when the ratio of GTE/DA/MXDA was 5:1:2. Highlights: An eco‐friendly dopamine‐supported dipping system was developed.The dipping solution (GTE/DA/MXDA) could successfully coat nylon 66 fibers.Treated nylon 66 possessed better thermal stability than untreated nylon 66.The adhesive strength was comparable to that obtained in a RFL system.The new dipping system shows great potential to replace RFL system. [ABSTRACT FROM AUTHOR]

Additive manufacturing of polymers is used for rapid prototyping and in specific applications for the fabrication of final products. As the application range grows to the industrial sector, functional parts require better mechanical properties and tighter tolerance ranges. Short-fiber reinforced polymers can handle higher stresses and significantly less deformation than raw AM polymers, but their surface roughness and viscoelastic behavior are poorly understood. The authors perform the dynamical mechanical analysis, line, and surface roughness characterization of fused filament fabricated composites in this work. Mainly, Onyx, a short carbon-filled fiber nylon thermoplastic composite, was used in three different build orientations: flat, on-edge, and upright. Then, the effect of build orientation on the viscoelastic and roughness properties is discussed. Results showed that despite using the same raw material, printing direction has a moderate impact on the viscoelastic behavior and a significant effect on the surface roughness of the part. For instance, a difference of 25 °C in the Tg was observed between the on-edge and upright build orientation, with the latter the highest. Also, the flat print orientation presented the lowest values in the z-roughness of all the three build orientations analyzed. [ABSTRACT FROM AUTHOR]

This study describes a novel approach using fibrous Al2O3-Nylon 6 composites to induce inhibition behavior in silica scaling systems. The composite fibers were fabricated with a wet-spinning process using the coagulation of a methanolic Nylon-CaCl2 solution with Al2O3 powder after immersing the thread-like solution in water. The mesoporous nylon fibers composed of Al2O3 powders ranging from 10 to 30 wt% loading demonstrated superior adsorption capabilities to silica in water, behaving with the Freundlich model and exhibiting effective multilayer adsorption onto the Al2O3 sites embedded in the fiber. Furthermore, the composite fibers inhibited silica scaling, even at high concentrations, due to a substantially efficient reduction in soluble silica when the composite fiber was present in the system. The utilization of 15 g of composite fibers resulted in a rapid drop to approximately 30 mg/L within the initial 10 h, which is a considerable improvement compared to the 300 mg/L observed in the fiber-free control sample. Notably, the presence of an elevated fiber content exceeding 7.5 g demonstrated the complete inhibition of silica precipitation. An analysis of the pore volume using nitrogen adsorption experiments before and after silica adsorption showed that silica adsorption resulted in a significant decrease in mesoporous properties at the alumina sites. This indicated an efficient adsorption of silica onto the alumina site, effectively removing silica from the system. [ABSTRACT FROM AUTHOR]

Reactive dyes in nylon dyeing have been associated with utilization inefficiencies despite their high color fastness. A potential solution to this issue involves combining the benefits of reactive dyes and milling acid dyes to obtain low-water-soluble reactive dyes (LWSRDs), which can stain and fix to nylon fibers under neutral conditions. To identify a suitable functional group for LWSRDs, six model dyes comprising one vinyl sulfone and five monochloro- s -triazines were prepared and reacted with glycine or hydrolyzed to simulate the fixation progress on nylon fibers. The results show that vinyl sulfone exhibited sufficient reactivity with glycine, and ∼3% hydrolysis over 90 min. Consequently, vinyl sulfone was considered a superior functional group for LWSRDs. Based on these results, four LWSRDs with monofunctional groups were synthesized and used for dyeing nylon 6 microfibers. Notably, these dyes exhibited fixation of >91% and demonstrated exceptional color fastness against washing and rubbing, exceeding grade 4. These results underscore the potential of LWSRDs as highly efficient and effective dyes for nylon, offering a solution to the limitations associated with conventional dyeing techniques. [ABSTRACT FROM AUTHOR]

Incorporating flame‐retardant compounds into polymeric composites is a key area of materials research. Halogenated flame‐retardants are most widely used; however, they are under scrutiny due to health and environmental concerns which increases interest in eco‐friendly alternatives. Tannic acid (TA) is a naturally occurring polyphenol with flame‐retardant properties. To overcome current challenges incorporating TA into polymer composites at high concentrations, nonwoven mats of nylon/TA composite nanofibers are fabricated using electrospinning. TA is incorporated at concentrations up to 50 wt% while maintaining uniform fiber morphology. Thermogravimetric analysis (TGA) shows TA within the nanofibers degrades at 230 °C and nylon degrades at 400 °C, irrespective of the initial TA concentration. Char yield increases with the concentration of TA, resulting in a maximum of 25% for fibers containing 50 wt% TA. Flame resistance is characterized using microscale combustion calorimetry (MCC) which shows composite fibers have reduced heat capacity and total heat release (THR) indicating flame resistance at ≥75 rel. wt%. Finally, ignition tests and condensed phase analysis show that TA acts as an intumescent material when embedded within the polymer matrix which produces an insulating foam‐like char under direct heat that eliminates flaming melt dripping and results in self‐extinguishing nanofibers. [ABSTRACT FROM AUTHOR]

Broaching is a semi-closed cutting process where the cutting fluid cannot act directly on the cutting area, resulting in insufficient lubrication and deteriorating machining quality, reducing tool life. Therefore, this paper proposes a self-lubricating cutting tool with excellent capabilities for continuous lubrication. First, a meshed texture is prepared on the rake face of cutting teeth using a laser. Electrostatic flocking is then used to vertically implant nylon fibers with good wear resistance into the texture. The cutting performance of non-textured, textured, and flocking tools is investigated under different lubrication conditions (dry/castor oil). The results show that the flocking tool reduces the cutting force by 7.2% under dry cutting and 16.5% under oil lubrication compared to the non-textured tool. The implantation of nylon fibers makes it easier for the chip to curl, thereby reducing the contact length between the tool and the chip and significantly decreasing the cutting force. Wetting experiments verify that the fibers accelerate the spreading of high-viscosity castor oil on the tool surface. Its excellent capability for continuous lubrication ensures an adequate supply of lubricant to the cutting tool. [ABSTRACT FROM AUTHOR]

Despite six decades of microplastic contamination research, this field struggles to establish clear, universally accepted methods and techniques. Furthermore, scant published work scrutinizes the application, effectiveness, and utility of positive and negative controls. This study examines three common practices involved in microplastic processing, enumeration, and particle characterization. The first component evaluates four filtered water sources that are commonly used to run procedural laboratory blanks and rinse laboratory glassware and instruments. A statistically significant difference was found between tap water and three sources of filtered water and between two sources of filtered water. This suggests the magnitude of correction applied to samples is dependent on the type of filtered water chosen for blanks. The second component chronicles particle loss, specifically particle adhesion to the filtration apparatus. Water samples spiked with plastic standards representing three distinct morphologies and vacuum filtered through a two-piece borosilicate glass filtration apparatus yielded a notable difference in recovery rates compared to a two-piece filtering apparatus made of stainless steel. The steel filter had significantly higher recovery rates of irregular polyethylene fragments compared to glass, although there was no statistical difference in the recovery of nylon fibers or symmetrical polyester fragments. The final component compares the effectiveness of ImageJ, a popular imaging software program, with Material Image Processing and Automated Reconstruction (MIPAR), a new program with deep learning capabilities. Both systems analyzed identical images captured from a set of polycarbonate filters that contain environmental media spiked with plastic standards. While ImageJ is capable of reporting particle enumeration, as well as basic measurement and categorization, it grossly overestimated fragments and frequently mischaracterized fibers. Particle count summaries from MIPAR, however, were in accord with the known quantity of standard spiked into each sample. These findings underscore the importance of quality controls when developing new methods or when modifying established methods. [ABSTRACT FROM AUTHOR]

An experimental study is performed to determine the head mechanics of American football helmets equipped with novel fiber energy absorbing material (FEAM). FEAM-based padding materials have substrates of textile fabrics and foam made with nylon fibers using electro-static flocking process. Both linear and angular accelerations of the sport helmets are determined under impact loads using a custom-built linear impactor and instrumented head. The effectiveness of padding materials and vinyl nitrile (VN) foam for impact loads on six different head positions that simulate two helmeted sport athletes in real-time helmet-to-helmet strike/impact is investigated. A high-speed camera is used to record and track neck flexion angles and compare them with pad effectiveness to better understand the head kinematics of struck players at three different impact speeds (6 m/s, 8 m/s, and 10 m/s). At impact speed of 6 m/s and 8 m/s, the FEAM-based padding material of 60 denier fibers showed superior resistance for angular acceleration. Although novel pads of VN foam flocked with 60 denier fibers outperformed with lowest linear acceleration for most of the head positions at low impact speed of 6 m/s, VN foam with no fibers demonstrated excellent performance for linear acceleration at other two speeds. [ABSTRACT FROM AUTHOR]

This study investigated the tensile behavior of some prevalent synthetic fiber ropes made of polyester, polypropylene, and nylon polymeric fibers. The aim was to generate well-documented experimental statistics and develop simplified stress–strain constitutive laws that can describe the ropes' tensile response. The methodology involved analyzing the thermal history of the fibers using the DSC technique, tensile testing of fibers and yarn components of the rope, and conducting 196 rope tensile tests with optimum testing conditions. Based on the test results, an experimental database of the ropes' tensile characteristics was established, containing different parameters of material properties, rope construction, fiber processing, fiber tensile properties, and rope tensile responses. Subsequently, ANN models were developed and optimized using MATLAB based on the generated dataset's inputs and outputs to predict the studied ropes' tri-linear stress–strain profiles. The results showed that the ANN models accurately predicted the stress–strain properties of ropes represented by the tri-linear approximation with an error of about 5% for the failure strength and strain. The study provides insight into the process-structure–property relationship of synthetic fiber ropes and contributes to minimizing the cost and effort in designing and predicting their tensile properties while contributing to the practical industry. [ABSTRACT FROM AUTHOR]

The objective of the study was a pre-screening of the microplastic (MP) content in surface water and benthic sediments of Kara Darya and Chirchiq rivers, the first-order tributaries of the Syr Darya River (Uzbekistan). For the first time, surface water and benthic sediment samples were taken from this region, and quantitative screening of MPs 0.15–5.00 mm in size was performed. A combined visual and μRaman-based methodology was used to quantify and characterize artificial polymer microparticles from the surface water and bottom sediments of two rivers. The average abundance of MPs in the Kara Darya River and Chirchiq River waters was found to be 4.28 ± 0.09 and 0.95 ± 0.36 items per m3, and that in benthic sediments attained 244 ± 28.9 and 333 ± 11.5 items per kg of dry soil, respectively. MP concentration in surface water and benthic sediments of the Kara Darya River significantly exceeded (p-value < 0.01) that in the Chirchiq River. Microfibers were most abundant; the proportion of MP fibers in the water of the Kara Darya and Chirchiq rivers amounted to 89 and 95%, respectively, and that in benthic sediments of the rivers was 86 and 84%, respectively. The dominance of microfibers may indicate the route of entry to the rivers through domestic wastewater treatment plant discharges. The polymer microparticles in the surface water and benthic sediments of the Kara Darya and Chirchiq rivers were mainly represented by polyethylenterephtalate (PET), which accounted for half of all MPs detected in the Kara Darya River. Microparticles of textile origin were particularly abundant in the Kara Darya River, where viscose and nylon fibers were also found, which suggests the leading role of synthetic textiles in the pollution. The reported data are the first experimental evidence of MP pollution of the Syr Darya tributaries, but the distribution and circulation of MPs in surface water in Central Asia requires further comprehensive studies. [ABSTRACT FROM AUTHOR]

The pursuit of a renewable and recyclable material to reduce carbon footprint is the need of the hour for a safe and secure future of flora and fauna. This study explores the reinforcement potential of pre-treated recycled nylon fiber (NF) with CaCl2, NaOH and silane in a polypropylene (PP) matrix. Silane coating over the fiber surface was confirmed from FTIR and surface morphology. Interfacial interactions among NF and PP were further strengthened by adding nano-structured cetrimonium bromide (CTAB) treated fly ash (FA). A positive hybridization effect of FA was observed on such hybrid composites, apparent from an increment of ∼29% in tensile, ∼49% in flexural, and ∼970% in notched Izod impact strength. FE-SEM analysis showed good dispersion and distribution of reinforcements into the base matrix, establishing excellent interfacial adhesion. DSC analysis showed an increase in crystallization temperature (∼125°C) and a decrease in melting temperature of all the composites, while TGA confirms a reduction in the activation energy of all the composites. [ABSTRACT FROM AUTHOR]

Electrospun nanofibers have unique characteristics like high aspect ratio, surface area, easy processability, and scaling-up ability that make them attractive candidates as reinforcements. Here we report on facile in-situ fabrication method of nanofiber-reinforced polydimethylsiloxane (PDMS) nanocomposites. Electrospun nylon six nanofibers are embedded randomly in PDMS matrix to achieve high mechanical properties, optical transparency, and flexibility. The fabricated electrospun nylon nanofiber-reinforced PDMS nanocomposite exhibits improved mechanical strength compared to the reference PDMS, and it can be utilized in soft electronic devices such as electrolytes and separators for batteries and insulating/passivation layers, wearable electronic devices, microfluidic devices, and epidermal electronics. [ABSTRACT FROM AUTHOR]

Nylon is a biocompatible thermoplastic polymer that is well known for its excellent fracture resistance, making it suitable for fabricating fiber-reinforced composite (FRC)-based dental bridges. FRC is widely used in dentistry. This study aimed to investigate the structural and morphological characteristics of the nylon 6 fiber prepared using five different weights of nylon 6 dissolved in formic acid. The nylon 6 fiber was successfully fabricated via a simple wet spinning method using water as a coagulant. The fiber was then characterized using Fourier transform infrared (FTIR) spectroscopy, optical microscopy, and scanning electron microscopy. FTIR spectroscopy confirmed the presence of nylon 6 characteristics in the fiber in the form of N-H and C=O groups at a specific wave number. The differences in the diameter and morphological shape of the fiber were attributed to the nylon 6 different concentrations. Furthermore, the nylon 6 fiber can be used to produce cost-effective products and realize suitable characteristics for use as an alternative to traditional materials for fabricating direct dental bridges. [ABSTRACT FROM AUTHOR]

The interface compatibility between the surfaces of nylon 66 (PA66) fiber and the acrylic rubber (AR) is the key factor to improve the mechanical properties of the composite materials. In this study, Lewis acid (CaCl2) was firstly used to reduce the crystallinity of PA66 fiber, and then a bioinspired polydopamine (PDA) function coating was constructed on the PA66 fiber surface to act as a bridge to introduce an epoxy‐functionalized silane layer (KH560). After that, the modified PA66 fiber was introduced in the CuSO4 coordination crosslinked AR composites to further increase the mechanical performances of AR. Results showed that Lewis acid could significantly reduce the surface crystallinity of PA66 fiber, the PDA coating has successfully coated the fiber surface. And SEM results showed, the interfacial compatibility between the fiber and rubber was obviously improved. Compared with the unmodified PA66 fiber filled AR composites, the tensile strength, modulus and hardness of the modified PA66 fiber filled AR composites were increased by 95%, 49%, and 16% respectively. [ABSTRACT FROM AUTHOR]

In recent years, fused deposition modeling (FDM) based on material extrusion additive manufacturing technology has become widely accepted as a cost-effective method for fabricating engineering components with net-shapes. However, the limited exploration of the influence of FDM process parameters on surface roughness parameters, i.e., Ra (average surface roughness), Rq (root mean square surface roughness), and Rz (maximum height of the profile) across different sides (bottom, top, and walls) poses a challenge for the fabrication of functional parts. This research aims to bridge the knowledge gap by analyzing surface roughness under various process parameters and optimizing it for nylon carbon fiber printed parts. A definitive screening design (DSD) was employed for experimental runs. The Pareto chart highlighted the significant effects of layer height, part orientation, and infill density on all surface roughness parameters and respective sides. The surface morphology was analyzed through optical microscopy. Multi-response optimization was performed using an integrated approach of composited desirability function and entropy. The findings of the present study hold significant industrial applications, enhancing the quality and performance of 3D printed parts. From intricate prototypes to durable automotive components, the optimized surfaces contribute to production of functional and visually appealing products across various sectors. [ABSTRACT FROM AUTHOR]

Inadequate lubrication of the two touching surfaces during friction can lead to severe wear, especially in metal cutting. Therefore, a surface with synergistic anti-friction effect of texture and solid lubricant was proposed to improve lubrication. A mesh texture with excellent wettability was prepared on the high-speed steel (HSS) surface by laser, and then nylon fibers were vertically implanted into the grooves of the texture using the electrostatic flocking technology. The friction and wear state of different surfaces (smooth, textured, flocking) under dry/oil-lubricated were studied by a linear reciprocating wear tester. The coefficient of friction (COF) under different working conditions was used to analyze the anti-friction properties, and the wear rate was used to evaluate the wear resistance of the surface. The results showed that the tribological properties of flocking surfaces were better than those of the other two surfaces. This is because the addition of nylon fibers eases shear at the edges of the texture. The broken fibers form a solid lubricating film on the specimen surface, which prevents the surface from being scratched by debris. In addition, it is found that COF decreases with increasing load. Finally, the rapid wettability of the oil droplets on the flocking surface shows the great potential of the surface for lubrication and anti-friction. [ABSTRACT FROM AUTHOR]

• Industrial plastic wastes reinforced with waste nylon fibers for floor tiles. • The evaluated performances of the composite floor tiles depend on the tested property. • The developed tile composites from recycled plastic and fiber wastes are viable. Industrial plastic waste is growing globally at an alarming rate and environmental pollution from traditional landfill disposal and incineration treatments are of great concern. As a strategy to reduce plastic pollution, value-added composite materials from industrial plastic wastes reinforced with recycled nylon fibers for use in floor paving tile applications were developed. This is to address the disadvantages of existing ceramic tiles which are relatively heavy, brittle, and expensive. The plastic waste composite structures were produced via compression molding technique at an optimized randomly oriented constant fiber volume fraction of 50 wt% after the initial sorting, cleaning, drying, pulverizing, and melt-mixing. The molding temperature, pressure, and time for the composite's structures were 220 ℃, 65 kg.cm −3, and 5 min respectively. The composites' thermal, mechanical, and microstructural properties were characterized in accordance with appropriate ASTM standards. From the results obtained, the differential scanning calorimetry (DSC) of mixed plastic wastes and nylon fiber wastes showed a processing temperature range of 130–180 ℃, and 250 ℃ respectively. Thermal degradation temperature (TGA) of the plastic and nylon fiber waste composites were stable above 400 ℃ with maximum bending strength, however, the reinforced plastic waste sandwiched composite structures had outstanding mechanical properties indicating unique characteristics suitable for floor paving tiles. Hence, the current research has developed tough and lightweight tiles composites that are economically viable, and their application will contribute to the development of the building and construction sectors thereby reducing about 10–15% of annual plastic waste generation and a sustainable environment. [ABSTRACT FROM AUTHOR]

This paper aims to experimentally study the compressive and flexural characteristics of cement-based composites developed for fabricating thin, lightweight, and high-performance components of buildings. Expanded hollow glass particles with a 0.25–0.5 mm particle size were used as lightweight fillers. Hybrid fibers made of amorphous metallic (AM) and nylon fibers were used to reinforce the matrix with a total volume fraction of 1.5%. The primary test parameters included the expanded glass-to-binder (EG/B) ratio, the fiber volume content ratio, and the length of the nylon fibers in the hybrid system. The experimental results demonstrate that the EG/B ratio and the volume dosage of the nylon fibers exhibited insignificant effects on the compressive strength of the composites. Additionally, the utilization of nylon fibers with a longer length of 12 mm resulted in a slight compressive strength reduction of approximately 13% compared to that of the 6 mm nylon fibers. Further, the EG/G ratio exhibited an insignificant effect on the flexural behavior of lightweight cement-based composites in terms of their initial stiffness, strength, and ductility. Meanwhile, the increasing AM fiber volume fraction in the hybrid system from 0.25% to 0.5% and 1.0% improved flexural toughness by 42.8% and 57.2%, respectively. In addition, the nylon fiber length significantly affected the deformation capacity at the peak load and the residual strength in the post-peak stage. [ABSTRACT FROM AUTHOR]

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