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This study is aimed to investigate the types of knot failure (untying or breaking) and the tension required to break different suture diameters. A total of 150 knots were fabricated using polyamide sutures with diameters of 6/0, 7/0, and 8/0. The studied knots were either squared or slipped with different numbers of throws (2, 3, 4, 5, and 6), and the following data were recorded: type of failure (untied or broken), number of throws, the tension required to untie or break each knot, slippage, and elongation of the knot. The knots were created in a standardized way with a device and weights, then subjected to a controlled tension. The knots that became untied were: 1=1, 1×1, 2=1, and 2×1, whereas the remaining knots broke. Notably, at least three throws were required to prevent untying, but separately, as in 1=1=1 or 1×1×1. The mean tension needed to break the knots in 6/0, 7/0, and 8/0 sutures were 3.1, 1.3, and 0.6 N, respectively (P < .05), and they were independent of the knot type. The results from this study demonstrate that the knots with geometries of 2=2/2×2 and 1=1=1/1×1×1 were secure, and having additional throws does not increase their security. Further, tensile strength reduces with decreased suture size. [ABSTRACT FROM AUTHOR]

The 3D printability of several thermoplastic feedstocks, recycled from post-industrial or post-consumer waste and the properties of printed items are presented and discussed. A preliminary investigation has been conducted with post-industrial scraps of PETG and PLA recycled into printable filaments. A comparison with samples produced with corresponding virgin materials showed similar mechanical characteristics. The printability of virgin, recycled and recycled/UVA exposed ABS pellets from extruded scraps is also compared. Recycled pellets were aged by exposure to UVA light up to 400 hours. The results of mechanical tests of 3D printed specimens indicate that the printability of recycled and artificially aged ABS pellets is still acceptable. Furthermore, nylon fibres recycled from clothing were used as feedstock for 3D printing. A simple and inexpensive recycling process is proposed to recover extruded pellets from nylon t-shirts. On the other hand, 3D printing tests showed that the recycled nylon has some prospects for 3D printing, but only if mixed at low percentage with virgin polymer. [ABSTRACT FROM AUTHOR]

Infrared (IR)-transparent radiative cooling textiles show great promise for achieving personal thermal comfort and reducing energy consumption. However, besides a few synthetic fiber materials proposed as IR-transparent textiles, traditional textile materials used to achieve IR transparency have not been realized, impeding large-scale practical applications. Here, based on a common textile material Nylon 6 (PA6), we design a high drawing process with rapid solvent evaporation to achieve IR-transparent PA6 textiles. By altering the chain conformations and crystal structures, the molecular vibrations in the IR region (IR absorption) of PA6 can be significantly weakened. Meanwhile, this process also tailors the fiber to the nanoscale and minimizes IR reflection. Consequently, a human body covered by our textile can stay 2.1 °C cooler than with cotton, corresponding to ~20% indoor energy savings in cooling. We expect that our work offers an innovative pathway to regulate IR radiation for personal thermal management. Infrared (IR)-transparent textiles are promising for thermal management systems, but fabrication from traditional textile methods remains challenging. Here, the authors propose a drawing process for Nylon 6 with high IR-transmittance and temperature reduction. [ABSTRACT FROM AUTHOR]

Preventing droplets from penetrating fabrics is critical in surgical wards and the battlefield, where biological and chemical hazards are dispersed and transmitted in droplet form. Here, we study the interaction between droplets and a nylon textile using high-speed imaging. We explore various droplet impact velocities and liquids to understand the influence of liquid characteristics on the impact behaviour. Importantly, we investigate the impact dynamics of droplets on textiles subjected to various tensile forces. Critical phenomena, such as droplet penetration and capture, are analyzed. We find that the critical impact velocity for droplet penetration increases as the stretching tension in the textile decreases. Furthermore, we present a simple model to predict the critical conditions for droplet penetration and capture that takes into account the surface tension, the droplet size, density and speed, the tensile load and the textile contact angle. We validate the model through experiments, demonstrating a strong agreement. These insights hold significant implications for the design of protective garments, such as face-masks and water-repellent clothing. [ABSTRACT FROM AUTHOR]

In recent decades, carbon fiber, glass fiber, polyester and Kevlar fiber have been utilized to replace the steel shims in conventional steel-reinforced elastomeric isolators (SREIs). This study chose nylon fabrics owing to their extreme low cost, low elastic modulus and good adhesion to rubber, and nine nylon fabric-reinforced elastomeric isolators (N-FREIs) were manufactured with different design parameters. Compression and compression shear tests were, respectively, conducted to investigate the mechanical properties together with their influential factors of the N-FREIs. Results show that the vertical load-carrying capacity of the isolator is high enough to sustain a compressive stress of 10 MPa without visible damage. The compressive stiffness of N-FREI is much smaller than that of SREI, and the vertical damping ratio under cyclic compression reaches up to 7%. In the compression shear tests, the shear stiffness of the isolator first decreases and then increases as the shear strain increases within 300%, and the equivalent damping ratio varies between 9% and 14% for different sizes of the isolator. Additionally, due to the flexibility and extensibility of the low modulus nylon fabric, both vertical and horizontal stiffness decrease a bit with an increase in the number of fabric layers. Finally, a formula for calculating the horizontal stiffness of N-FREI is proposed, it provides a comprehensive mathematical model to predict the behavior of the N-FREI under horizontal shear conditions. [ABSTRACT FROM AUTHOR]

Natural dyes offer a harmless alternative to synthetic counterparts, minimizing the release of toxic chemicals associated with synthetic dyes. In this investigation, nylon fabrics underwent dyeing with neem leaf extract under acidic, neutral and alkaline conditions along with lemon juice mordant. The study revealed that colour strength exhibited an increase with decreasing pH levels, with the mordanted fabric dyed in an acidic medium demonstrating the highest value. Analysis of colour coordinates indicated that the mordanted fabric dyed in an acidic medium exhibited superior colour pickup compared to the other samples. Enhanced fastness properties were achieved under acidic pH conditions when a mordant was used. The FTIR test result ensured the nylon-lemon juice-neem leaves extracted dye interaction. The EDX analysis also confirmed the elemental composition of neem leaves extracted dye in nylon assisted by lemon juice. The SEM test results validated the dyeing process empirically. [ABSTRACT FROM AUTHOR]

Zn acetate is an efficient catalyst for the synthesis of novel 3,4-dihydropyridine-2(1H)-ones (DHPMs) scaffolds via a triple cascade Biginelli reaction among polynuclear carbaldehyde, lawsone, and thiourea. All newly prepared compounds were confirmed by various spectral analysis. UV–visible spectral analyses were performed to study their intense depth of color. Prepared dyes were evaluated for dyeing performance on nylon and polyester fabrics, including the wash, light, rubbing and sublimation fastness. A color assessment, determination of percentage exhaustion, and fixation properties were also investigated. Results of all these studies were compared with lawsone, which is one of the starting materials for the synthesis of all these new disperse dyes. It has been observed that the prepared novel dyes greatly impacted their dyeing properties on both fabrics compared to lawsone. They have shown brilliant shades, higher affinity, superior tinctorial strength, and higher adsorption capacity than the lawsone. This report reveals the significance of prepared disperse dyes with great application value for nylon and polyester fibers. [ABSTRACT FROM AUTHOR]

The textile industry's rapid growth and reliance on synthetic fibres have generated significant environmental pollution, highlighting the urgent need for sustainable waste management practices. Chemical recycling offers a promising pathway to reduce textile waste by converting used fibres into valuable raw materials, yet technical challenges remain due to the complex compositions of textile waste, such as dyes, additives, and blended fabrics. [ABSTRACT FROM AUTHOR]

A number of rectified nylon harp strings, having the same nominal diameter, were subjected to different sequences of applied stress steps. Each string was tested continuously for several weeks to allow sufficient time for the stretching responses to be clearly observed. Qualitatively, much of the observed behaviour was in accordance with established expectations. However, the quantitative data gathered here are believed to be novel, and revealed some surprises. The strings displayed a combination of elastic stretching, fully recoverable viscoelastic stretching, and apparently non-recoverable plastic stretching. The elastic and recoverable viscoelastic stretching behaviour was quite straightforward, but the plastic creep behaviour was more complicated, with a number of the strings displaying an unanticipated phenomenon. When the applied stress was left unchanged, or was stepped down and back up again, it was noticed that, in some cases, the extent of the subsequent plastic stretching, when the applied stress was next increased beyond its previous maximum, was significantly less than might have been expected. The tests revealed that this apparent plastic creep 'constraint' mechanism seemed to depend primarily on the length of time between successive overall rises in the applied stress, with a threshold somewhere in the range of 30–40 days. It is suggested that this phenomenon may be due to a gradual increase in the polymer crystallinity during this rest period. Two of the strings, which were tested over a wider range of applied stress levels, revealed another aspect of the creep behaviour. There appeared to be an initial 'straightening' phase during which the plastic stretching rose with the applied stress in a diminishing manner to reach a stretching limit. As the applied stress was increased, this initial straightening was overtaken by an unlimited main stretching phase, which rose slowly at first before approaching a linear increase with the applied stress. [ABSTRACT FROM AUTHOR]

This study addresses the issue of low surface energy of aramid fibers and their fabrics and aims to enhance their mechanical properties including tensile strength and impact resistance. Using the hollow spindle spinning method, aramid fiber bundles are employed as the core yarns with varying twist levels and nylon fibers are used as the wrapping yarns to create the nylon/aramid-wrapped yarns, which are then woven into the nylon/aramid fabrics. The investigation focuses on the effect of core yarn twist levels on the mechanical properties of the yarns and fabrics. Experimental results reveal that applying an appropriate core yarn twist can significantly improve the mechanical properties of the yarns and fabrics. Specifically, with the optimized the core yarn twist of 80 turns per meter (tpm) the tensile and hook strengths of the wrapped yarns reach 3.3 GPa and 1.2 N/Tex, respectively which are about 20.6% and 21.7% increase as compared to the untwisted yarns. Similarly, the plain-woven fabric consisting of the 80 tpm yarns achieves a tensile strength of 2577.9 N/cm, a pull-out force of 160.2 N, and an absorbed energy per unit volume of 436.5 KJ/m3 which are about 20.0%, 31.4% and 30.1% improvement, respectively as compared to the fabrics with the untwisted yarns. Additionally, the optimized fabric presents a 28.4% increase in the energy absorption efficiency and significant enhancement in abrasion resistance. These findings offer valuable insights for the potential applications of the nylon/aramid-wrapped yarns for developing personal protective fabrics and products. [ABSTRACT FROM AUTHOR]

The immobilization of enzymes in polyamide-based polymeric materials through covalent bonding is an established technique to stabilize and reuse biocatalysts in industrial processes. Traditionally, enzymes are immobilized using crosslinking agents that activate functional groups on both the support and the enzyme, creating strong bonds that securely anchor the enzyme to the surface. While effective for maintaining enzyme activity over multiple cycles, this method can reduce catalytic efficiency due to rigid binding and involves complex activation steps. Recently, in situ immobilization approaches have emerged as promising alternatives. In this method, enzymes are directly entrapped within the polymer matrix during the synthesis of the polyamide support, such as nylon, simplifying the process and offering enhanced control over enzyme distribution. For instance, studies have demonstrated that in situ immobilization can improve enzyme stability by protecting it within the polymeric network, while reducing production costs and waste. This review explores the ability of polyamide as a support material for immobilization of enzymes, analyzing key techniques, performance across applications, and future strategies to optimize polymer-enzyme interactions for industrial use. [ABSTRACT FROM AUTHOR]

A comprehensive non-isothermal kinetics study on polymer crystallization processes taking place in a set of industrial polyamides comprising nylon 6, nylon 6,6, nylon 11 and nylon 12, individually, is reported. The kinetics studies elucidated that the phenomena of nucleation/diffusion underlying the nylons crystallization go to completion in a single-step. Notwithstanding, the nylons diffusion activation energies do not correspond to the universal value of segmental jump activation energy signifying polymer chains diffusion processes. The polymer chain transport phenomenon was probably the slowest one in the case of nylon 6 and nylon 6,6, and the fastest in the case of nylon 12, while intermediate for nylon 11. Furthermore, the nucleation barrier during the course of polymer crystallization was the highest for nylon 6,6, followed by nylon 6, nylon 11 and nylon 12. Our kinetics studies further predict that the crystallization of nylon 12 and nylon 11 follows, respectively, diffusion-controlled 2D growth of spherulites and a somewhat complicated nucleation/growth phenomenon. The thermodynamics of the nylons crystallization suggests that the highest structural orientation of the activated complex was attained in the case of the nylon 12 crystallization process. Interestingly, while the thermodynamics and majority of the kinetic parameters of nylon 6 and nylon 6,6 were similar/comparable, the two follow widely differing crystallization mechanisms. The most probable physical meanings of the obtained kinetics and thermodynamics parameters and their practical significance are given and discussed. [ABSTRACT FROM AUTHOR]

Background/aim Debris accumulation beneath the dentures initiates countless difficulties such as inflamed oral mucosa and denture stomatitis. Denture stomatitis is a prevalent pathologic illness that is commonly linked to Candida albicans. Accordingly, treatment requires applying effective anti-inflammatory and antifungal medicaments that do not negatively influence the properties of denture base materials. Antifungal oral gel and ozonated water have quite an impact on inhibiting Candida albicans growth and treating denture stomatitis, so they have been selected in this research. This study aimed to compare the effect of antifungal oral gel and ozonated water on the tensile and compressive strengths of poly methyl metha acrylate (PMMA) and Nylon or polyamide denture base materials. Patients and methods This study was carried out for two types of denture base materials; group I PMMA and group II Nylon or polyamide. Total samples for both groups were 160 and fabricated following American Dental Association specifications No.12 for assessing tensile and compressive strengths. For each group (80 samples each group), the compressive strength was measured before (10 samples each) and after (10 samples each) the application of antifungal oral gel (10 samples each), and ozonated water (10 samples each), overnight for 15 days for each. Also, the tensile strength was measured for each group before (10 samples each) and after (10 samples each) the application of antifungal oral gel (10 samples each) and ozonated water (10 samples each) overnight for 15 days for each. Comparison between pre and post measurements was accomplished by Paired t-test, while comparison between heat-cure PMMA and nylon was carried out by using an Independent t-test. Results PMMA was significantly affected by ozonated water regarding compressive (P =0.0001) and tensile (P =0.0001) strength while antifungal oral gel had a significant effect only on the tensile strength (P =0.0001) but not the compressive strength (P =0.57). Both antifungal oral gel (P =0.7) and ozonated water (P =0.75) have insignificant effects on the compressive strength of nylon denture base material and also insignificant effect on tensile strength of nylon denture base material (P =0.16) for ozonated water and (P =0.37) for antifungal oral gel. Conclusion Ozonated water could adversely impact both the compressive and tensile strength of PMMA denture base material and the antifungal oral gel could affect only its tensile strength. Ozonated water and antifungal oral did not affect the compressive and tensile strength of the nylon denture base material.

Abstract New azo Schiff base disperse dyes based on a chromene moiety were synthesized by reacting (2-amino-7-hydroxy-4-(4-methoxyphenyl)-4 H-chromene-3 carbonitrile) and(2-amino-4-(3,4-dimethoxyphenyl)-7-hydroxy-4 H-chromene-3-carbonitrile), with vanillin and ninhydrin, producing new chromene Schiff base derivatives, which in turn were coupled with 2-chloro-4-nitroaniline diazonium salt to give new 4 azo disperse dyes (1–4). The structures of the prepared dyes were confirmed using elemental analysis, 1HNMR spectroscopy, mass spectrometry, and IR. The synthesized dyes were applied to polyester and nylon fabrics using different dyeing techniques: high temperature- high pressure, and ultrasonic dyeing methods. The highest K/S values for all investigated dyes were achieved usinga high temperature-high pressure dyeing technique. Also, the color reflectance of all synthesized dyes with different dyeing shades (1%, 2%, and 3%) was obtained. The fastness properties of the dyed samples using the investigated dyes showed good color fastness toward light, washing, rubbing, and perspiration fastness. The presence of a chromene moiety and Schiff base in the investigated dyes promotes a higher antimicrobial activity on nylon and polyester fabrics against all tested bacteria (E. coli gram-negative and Staphylococcus aureus gram-positive) and two fungi, Aspergillus Niger and Candida albicans.

Polymer/transition metal inorganic salts nanocomposites are promising engineering materials in automotive, electronics, aerospace and smart wearables fields. However, the interfacial incompatibility always causes agglomeration and phase separation, constraining their further application. Inspired by inorganic oligomers' polymerization, nylon/nickel phosphate oligomer (NPO) nanocomposite (ENCC) was prepared via hydrogen bond crosslinking method. Due to the formation of hydrogen bonds between PO43− end groups of NPO with an average diameter of 6.5 ± 1.2 nm and NH groups on the nylon molecular chain, the phase compatibility is greatly improved. Hence, NPO was uniformly nano‐dispersed and had no obvious agglomerate in ENCC, inducing an invisible phase interface at nano‐micro scale. Nylon/nickel phosphate oligomer showed an excellent reinforcing effect on nylon, the tensile strength and elongation of ENCC reached 28 ± 0.8 MPa and 585 ± 26% at a high loading of 20 wt%, increased by 155% and 92%, compared with pure matrix, respectively. Furthermore, ENCC was still optically transparent and had excellent anti‐blue‐light performance (up to 96.6%). Highlights: Novel inorganic/nylon composite prepared by hydrogen bond crosslinking method.Phase separation and aggregation problems were solved remarkably.Inorganic metal phosphate dispersed with a diameter of 6.5 ± 1.2 nm.The composite was still transparent at 20 wt% loading of metal phosphate.Tensile strength and elongation increased by 155% and 92%, respectively. [ABSTRACT FROM AUTHOR]

Liquid‐solid triboelectric nanogenerator (LS‐TENG) harvests energy efficiently while eliminating wear issues associated with solid‐solid TENG. However, the effect of ions or charges in the liquid on output performance needs further examination. In this work, the impact of fluorine and copper ions introduced through deionized water with sodium fluoride (DI‐NaF) and deionized water with copper sulfate (DI‐CuSO4) solution on the output voltage, charge and current of a tubular LS‐TENG with polytetrafluoroethylene (PTFE) and Nylon as solid materials is examined. The results indicate that fluorine and copper ions have opposite effects on PTFE and Nylon LS‐TENG's output. The fluorine (F−) ions enhance the triboelectric effect and charge transfer in Nylon LS‐TENG, increasing output, while they hinder the charge transfer process in PTFE LS‐TENG, consequently decreasing its output. Conversely, the copper (Cu2+) ions have a positive effect on the output of PTFE LS‐TENG and a detrimental effect on Nylon LS‐TENG's output. Moreover, the results indicate that LS TENG's output performance depends on the charges of solid and liquid triboelectric materials. Thus, this study provides insights into material‐ion interaction in LS‐TENG and underscores the importance of triboelectric material selection for optimizing output performance. [ABSTRACT FROM AUTHOR]

Adipic acid (ADA) is a highly valuable industrial dicarboxylic acid used largely as a precursor of nylon 6,6 production. It is currently synthesized via a petrochemical process that accounts for over 80% of the global industrial N2O emissions. Biobased ADA offers a cleaner alternative but requires technological advancements in microbe and bioprocess performance to be commercially relevant. An in-depth feasibility analysis was conducted to evaluate two biobased pathways for the production of ADA, modeled as integrated sugarcane biorefineries in Aspen Plus®. The pathways examined were: (1) direct fermentation of sugars to ADA (S1-ADA) and (2) hydrogenation of biobased cis,cis-muconic acid to ADA (S2-ccMA-ADA). The impact of improvements to key bioprocess metrics (product yield, titer, and volumetric productivity) on the minimum selling price and greenhouse gas (GHG) emissions for both pathways was also evaluated in a full-factorial study. S1-ADA demonstrated the highest feasibility potential, achieving minimum selling prices and GHG emissions that were 33.3% and 78.7% lower, respectively, than those of fossil-based production. These results were obtained under conditions of optimal strain performance and bioprocess efficiencies. However, under comparable technological advancements, the best-achievable results for S2-ccMAADA indicated a green premium of 13.4% alongside a 68.4% reduction in emissions compared to the fossil-based product. Consequently, the direct biobased pathway (S1-ADA) shows greater potential to compete with and eventually replace its fossilbased counterpart once optimized. This finding highlights the need to prioritize S1-ADA for further biotechnological development. [ABSTRACT FROM AUTHOR]

In order to improve the hitting performance of badminton rackets, the creep characteristics of their nylon string were explored based on the Maxwell and Kelvin models. Special attention was given to the instantaneous elastic deformation coefficient, the delayed elastic deformation coefficient and the retardation time under different conditions. Based on the experimental results, models with high accuracy were developed for nylon, which can describe the changes in the creep rate at different times, relative humidities and stress levels. They all showed that the creep rate increases rapidly with time and then gradually becomes flat. The highest relative humidity led to the lowest instantaneous elastic deformation coefficient and delayed elastic deformation coefficient, but the highest retardation time for nylon. Finally, as the stress level increased, the instantaneous elastic deformation coefficient, delayed elastic deformation coefficient and retardation time all increased. Thus, to improve the hitting performance of badminton rackets, it is necessary to pay attention to the tension and the air humidity in the environment during use. [ABSTRACT FROM AUTHOR]

Compared with PELE with inert fillings such as polyethylene and nylon, reactive PELE (RPELE) shows excellent damage effects when impacting concrete targets due to the filling deflagration reaction. In present work, an analytical model describing the jacket deformation and concrete target damage impacted by RPELE was presented, in which the radial rarefaction and filling deflagration reaction were considered. The impact tests of RPELE on concrete target in the 592e1012 m/s were carried out to verify the analytical model. Based on the analytical model, the angle-length evolution mechanism of the jacket bending-curling deformation was revealed, and the concrete target damage was further analyzed. One can find out that the average prediction errors of the front crater, opening and back crater are 6.8%, 8.5% and 7.1%, respectively. Moreover, the effects of radial rarefaction and deflagration were discussed. It was found that the neglect of radial rarefaction overestimates the jacket deformation and concrete target damage, while the deflagration reaction of filling increases the diameter of the front crater, opening and back crater by 25.4%, 24.3% and 31.1%, respectively. The research provides a valuable reference for understanding and predicting the jacket deformation and concrete target damage impacted by RPELE. [ABSTRACT FROM AUTHOR]

Among superhydrophobic materials, non-wettable textiles arguably come in contact or interact with the human body most frequently. The author presents the proof-of-concept of a novel modification method for a woven fabric surface for realizing excellent hydrophobicity using two kinds of ultrashort-pulsed lasers. The key hypothesis is that to improve the hydrophobicity of the woven fabric, it might be necessary to not only improve the water repellency of the surface but also to prevent liquid seepage between filaments of the woven fabric. A woven fabric of Nylon 6 is addressed by (a) enhancing liquid hydrophobicity by applying micro-periodic structures on the filaments through a femtosecond-pulsed laser processing based on the Cassie-Baxter model, and (b) preventing liquid seepage between the network of filaments by utilizing picosecond-pulsed laser processing via thermal sealing. The optimal conditions for the laser processing were determined experimentally. This laser modification method exhibited an apparent contact angle of 120°, comparable to chemical treatments as a non-wettable application. A processed depth that was onefiftieth of the filament diameter was sufficient for improving the hydrophobicity of the woven fabric. The combination of laser processing effectively enhanced the water repelling and sealing of the woven fabric, indicating that excellent hydrophobicity was achieved. No significant difference was observed in color due to the laser processing, and the decrease in tearing strength was approximately 9%. These results highlight the possibility of strategies that can introduce a novel process for non-wettable woven fabrics as a sustainable technology. [ABSTRACT FROM AUTHOR]

Resuspended particles from human activities can contribute to pathogen exposure via airborne fomite contamination in built environments. Studies investigating the dissemination of resuspended viruses are limited. The goal of this study was to explore viral dissemination after aerosolized resuspension via human activities on indoor flooring. Nylon carpet or wood flooring was seeded with virus (MS2) or virus laden dust then evaluated after activities, i.e., walking and vacuuming. Statistically significant differences were found in dispersal of virus laden dust after vacuuming carpet (p-value = 5.8 × 10−6) and wood (p-value = 0.003, distance > 12 in/30 cm). Significant differences were also found between floor materials and virus laden dust dispersal vacuuming (p = 2.09 × 10−5) and walking (p = 2.68 × 10−2). A quantitative microbial risk assessment (QMRA) scenario using Norovirus and a single fomite touch followed by a single hand-to-mouth touch indicated a statistically significant difference associated with virus laden dust particles and vacuuming carpet(p < 0.001). Infection risks were 1 to 5 log10 greater for dust exposure. The greatest risk reductions from fomites were seen across vacuuming carpet no-dust scenarios for surfaces <30 cm from flooring. More research is needed to determine the role resuspension plays in exposure and transmission of potentially infectious agents. [ABSTRACT FROM AUTHOR]

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Lurik woven cloth is a traditional Indonesian textile. Its very existence is the primary potential for the national clothing in Indonesia. The word 'lurik' is derived from the type of motif generated by weft and warp threads, producing classic vertical or horizontal stripes. The growing lurik industry today produces an extensive variety of threads for specific uses, including polyester threads for fabrics and knitted products and nylon threads for the manufacture of accessories. Lurik woven cloth is a traditional Indonesian textile. Its very existence is the primary potential for the national clothing in Indonesia. The word 'lurik' is derived from the type of motif generated by weft and warp threads, producing classic vertical or horizontal stripes. The growing lurik industry today produces an extensive variety of threads for specific uses, including polyester threads for fabrics and knitted products and nylon threads for the manufacture of accessories. The objective of the experiment reported here is to develop a pattern design for the traditional lurik woven fabrics using an innovative strategy of graded color warp threads and various color weft threads to reach a wider target audience. The weft used in weaving is made of synthetic threads. Its weaving originality arises from the composition of bright and contrasting colors to create an active visual impact full of energy and passion. [ABSTRACT FROM AUTHOR]

This research presents a method to convert a conventional Nylon closed cell foam, with a density of 48 kg m−3, into auxetic metamaterials with densities ranging between 68 and 138 kg m−3. The samples are produced by applying vacuum and mechanical compression techniques. The study reports on the effect of processing parameters such as vacuum time, temperature, and mechanical pressure. Under optimized conditions, the resulting auxetic foams exhibit a tensile Poisson's ratio as low as −0.86, while the minimum compressive Poisson's ratio for the same sample reached −0.16. Based on morphological analyses via scanning electron microscopy (SEM), structural changes induced by the treatment are determined to relate with tensile and compressive properties, including modulus and strength, as well as the analysis of the stress level for different strains. The characterizations also include differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) for the Nylon foam before and after conversion. These findings underscore the potential applications of these auxetic foams in sports and military protective gears, as well as energy dissipation systems. [ABSTRACT FROM AUTHOR]

A semi-empirical model for the assessment and an optimization procedure of the sound absorption coefficient of compressed nonwoven fibrous materials made from recycled Nylon fibers (RNF) is developed. In general, the prediction of the sound absorption properties of materials requires the measurement of non-acoustic parameters by specialized characterization tools that are not always within reach of most laboratories. The objective of the proposed model is to establish empirical relationships between these non-acoustic parameters and the bulk density of RNF materials. These empirical relationships are then substituted into a conventional acoustic model for porous materials, namely, the model of Johnson-Champoux-Allard. The proposed model accurately predicts the sound absorption coefficients of compressed RNF materials based solely on bulk density, thickness, and frequency. This prediction is validated through impedance tube measurements. Moreover, the model is used with a proposed optimization producedure to identify the ideal density and thickness for maximum sound absorption at a specific frequency. Impedance tube measurements on optimized configurations confirm the effectiveness of this optimization process. [ABSTRACT FROM AUTHOR]

Highlights Hybrid fiber‐reinforced composites uniquely address the performance limitations of carbon fiber‐reinforced polymers (CFRPs). In this study, continuously wrapping large tow CF (48 K) with low‐cost nylon was proposed to create nylon‐CF core‐spun yarns (NCCYs). Unidirectional nylon‐CF/epoxy composites (NCFECs) were successfully fabricated using NCCYs as hybrid fiber reinforcement. The nylon wrapping on the CF significantly enhanced the energy absorption and dispersion of the CFRPs, thereby improving the impact strength. The measured impact strength of the NCFECs was 108.7 kJ/m2, which was 70.4% greater than that of the corresponding CF/epoxy composite (63.8 kJ/m2) with the same CF content. Additionally, NCCYs exhibited an excellent interfacial shear strength of 35.3 MPa, representing a 73.9% increase compared to that of the large tow CF (20.3 MPa). This study developed NCFECs using a simple and low‐cost process to produce advanced composites, providing an innovative manufacturing strategy for CFRPs with high impact resistance. The NCCYs are prepared by using the wrapping technology. The structure of the wrapped yarns endows the NCCYs with high interfacial shear. The nylon fiber layer gives NCFECs higher impact strength. [ABSTRACT FROM AUTHOR]

Polyamides (PAs) are extensively utilized across various applications, yet the accumulation of PA residues presents significant ecological and environmental challenges. Given that a substantial portion of fishing nets are composed of nylon, a type of PA, this material's disposal raises environmental concerns impacting marine life and the global ecosystem. Therefore, to enhance sustainability, they could be collected and recycled. This study introduces a method for the chemical recycling of PA waste using hydrochloric acid (HCl). Through solvolysis, a PA was depolymerized, and the effect of various reaction conditions on the depolymerization yield was analyzed, being the best conditions established in this work (100 °C, 4 h, and an HCl/PA ratio of 11:1, wt.wt−1). Next, a novel separation methodology was employed to isolate recycled products from salts formed during neutralization. Subsequently, these recycled products were incorporated as a partial substitute (up to 10% wt.wt−1) for a conventional PA in a new material production. The results indicate that the presence of recycled products enhances material stiffness due to crystallinity differences compared to the virgin matrix. In turn, the introduction of lower-molecular-weight species increases the materials' glass transition temperature (Tg) and their melt flow index (MFI). This research underscores a sustainable pathway for PA recycling aligned with circular economy principles, contributing positively to environmental conservation efforts. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) methods are increasingly being adopted as an alternative for mass production. In particular, Fused Deposition Modeling (FDM) technology is leading the way in this field. However, the adhesion of the layers in products produced using FDM technology is an important issue. These products are particularly vulnerable to forces acting parallel to the layers and especially to impact strength. Most products used in the industry have complex geometries and thin walls. Therefore, solid infill is often required in production, and this production must take place in the ZX orientation. This study aims to optimize the impact strength against loads acting parallel to the layers (ZX orientation) of PA6, one of the most widely used materials in the industry. This orientation is critical in terms of mechanical properties, and the mechanical characteristics are significantly lower compared to other orientations. In this study, filaments containing pure PA6 with 15% short carbon fiber and 30% glass fiber were utilized. Additionally, the printing temperature, layer thickness and heat treatment duration were used as independent variables. An L9 orthogonal array was employed for experimental design and then each experiment was repeated three times to conduct impact strength tests. Characterization, Taguchi optimization, and factor analyses were performed, followed by fracture surface characterization by SEM. As a result, the highest impact strength was achieved with pure PA6 at 8.9 kJ/m2, followed by PA6 GF30 at 8.1 kJ/m2, and the lowest impact strength was obtained with PA6 CF15 at 6.258 kJ/m2. Compared to the literature and manufacturer datasheets, it was concluded that the impact strength values had significantly increased and the chosen experimental factors and their levels, particularly nozzle temperature, were effective. [ABSTRACT FROM AUTHOR]

As a passive fishing gear, pocongan becomes a shelter for lobster fry. The material used to make pocongan is a 1 inch nylon mono-filament mesh size with a net height of 1.5-2 m. Pocongan is operated at night by floating bagan (pontoon) or boats and uses white LED lights, both surface and underwater. The aim of this research is to determine the composition of lobster fry catches as the main catch and other juveniles as by-catch and to determine the effect of using yellow and white LED lights on the operation of pocongan fishing gear. Experimental fishing activities were carried out for 10 trips with 2 treatments (yellow and white LED lights) and 3 pocongan units for each treatment. The results of the research showed that the use of yellow lights resulted in a greater number of lobster fry catches compared to white lights and had a significantly different effect. The use of yellow lights produces fewer by-catch catches compared to white lights. [ABSTRACT FROM AUTHOR]

This study explored the impact of varying concentrations of TiO2 NPs on the performance of TENGs made from nylon/TiO2 NCs. The TENGs were constructed using nylon films as one triboelectric material and polysiloxane (PS) as the other. Electrical measurements were performed to assess the TENGs' output parameters, such as open-circuit voltage and shortcircuit current, with different TiO2 concentrations (1%, 3%, and 5%). The findings revealed that increasing the TiO2 concentration initially enhances the TENG's performance. For example, TENGs based on 1% TiO2 NCs achieved maximum voltage and current values of 41.38 V and 2.5 µA, respectively, which are higher than those of ordinary nylon TENGs (30.36 V and 1.82 µA). This improvement is due to the increased dielectric constant of the NC material, which enhances charge storage capacity and boosts the TENG's output. However, when the TiO2 concentration is further increased (e.g., to 5%), the TENG's performance begins to decline. This drop is caused by the agglomeration of TiO2 NPs on the nylon surface, which reduces the active contact area between the nylon and PS films, weakening the triboelectric effect. Similar patterns were observed in TENGs with 3% and 5% TiO2xs concentrations, where excessive TiO2 led to a decrease in output power due to uneven nanoparticle distribution. [ABSTRACT FROM AUTHOR]

In this paper the effect of particle shape and size on the mechanic behavior of glass-particle reinforcing Nylon matrix composite is evaluated. There are many parameters effecting on the composite such as types, size, position and shape of reinforcement material. Particle morphology has received enormous interest in particulate composite; small particles adhere strongly to the polymer, which leads to a strong reinforcing effect. The objective of this research is to investigate the influence of reinforcement shape and size with different volume fractions and for three packing (square, hexagonal and random) using finite element method. The composite is subject to unidirectional tensile loading. Numerical results are presented for a variety of particle shapes and size including circular, triangular, square and two distributions grouping these shapes together. The results show that the variation of the Von Mises and longitudinal stresses consistently increased when the shape of the reinforcement changed from triangle to square, distribution 1 and distribution 2 to circular in this order. [ABSTRACT FROM AUTHOR]

Soft grippers, generating movement immediately, are generally based on flexible materials actuated by air pressure and comprised of bulky parts, including valves, compressors/pumps, motors, and tubes. In this work, a compact soft gripper with the ability to actuate with a low boiling point liquid (acetone) is presented. SolidWorks 2021 software and 3D printing technology are used to design and manufacture the gripper molds, respectively. The constitutive material of the soft gripper body is highly flexible Ecoflex. A silver‐coated nylon fabric (SCNF) heater reinforced with stainless steel yarn (SSY) covering the external surface of the gripper is designed and manufactured using Autocad 2021 and a laser cutting machine, respectively. The idea is inspired by floating the gripper in warm water to provide smooth heat over a large surface area. The available commercial software Abaqus2021 is used to simulate the mechanical deformation of the gripper, and its results are verified with experimental results. The parameter's effect including the voltage and low boiling liquid volume on achievable force and actuating time are investigated. The relation between the electrical, thermal, and mechanical properties of the presented gripper is discussed in detail. [ABSTRACT FROM AUTHOR]

Body odorants typically transfer to clothing fabrics by way of liquid sweat, yet investigations of odor retention in textiles often neglect this route of exposure in their test procedures. This paper describes a novel method for transferring selected odorous volatile organic compounds to six types of textile fibers in yarn bundle form by an aqueous sweat solution. Headspace volatile organic compounds varying by chemical class (ketones, aldehydes, carboxylic acids) were monitored at discrete time intervals (30 min, 3 h, 24 h) using proton transfer reaction mass spectrometry. Lower intensities of ketones and aldehydes were detected in the headspace above cellulosic fibers (cotton, mercerized cotton, viscose) than above wool, nylon, and polyester fibers at 30 min. A rapid decrease in ketones occurred for all fibers, but lower intensities of ketones were released after 3 h for cellulosic and wool fibers. Nylon fibers typically released the highest amounts of ketones and aldehydes at 30 min, but by 24 h higher intensities of these compounds were released from polyester. Carboxylic acids exhibited minimal differences in intensities between 30 min and 3 h, with few differences evident among fiber types. Understanding the preferential sorption of odorants when clothing is exposed to volatile organic compounds in aqueous solutions such as sweat is enhanced from the results of this investigation. [ABSTRACT FROM AUTHOR]

In this paper, the potential of beetroot as a natural source to dye a synthetic fiber that is, nylon 6 fabric, has been examined. We analyzed the impact of the most important dyeing parameters, such as dyeing temperature, dyeing time, pH of the dye bath, and dye concentration, on the dyeing efficiency of the nylon 6 fabric. We achieved the optimal conditions for nylon dyeing by beetroot at the boiling temperature for 60 min using 100% on the fabric weight (owf) dye under acidic conditions. Also, to attain suitable color fastness, we used four different natural mordants (pomegranate peel, walnut husk, pistachio hull, and Terminalia Chebula) before the dyeing process. We also examined the effect of four commonly used metal mordants on the dyeing efficiency. FTIR, SEM, EDX and TGA were then conducted to justify the presence of mordants and dyes on the substrate. We discovered that pre‐mordanting generated colorful fabrics based on the type of mordants used. Also, various natural mordants could produce different color strengths, such that the walnut husk had the highest color strength among the used mordants. The obtained color fastness against washing of all bio‐mordants was rated as excellent and the light fastness of Terminalia Chebula was surprisingly excellent. Bio‐mordants also exhibited equivalent washing fastness to metal mordants, even surpassing them in terms of light fastness. The EDX spectra also showed peaks corresponding to carbon (C), nitrogen (N), and oxygen (O). Finally, the fabric mordanted with pomegranate peel exhibited very less mass loss, thus indicating thermal stability. [ABSTRACT FROM AUTHOR]

New azo Schiff base disperse dyes based on a chromene moiety were synthesized by reacting (2-amino-7-hydroxy-4-(4-methoxyphenyl)-4 H-chromene-3 carbonitrile) and(2-amino-4-(3,4-dimethoxyphenyl)-7-hydroxy-4 H-chromene-3-carbonitrile), with vanillin and ninhydrin, producing new chromene Schiff base derivatives, which in turn were coupled with 2-chloro-4-nitroaniline diazonium salt to give new 4 azo disperse dyes (1–4). The structures of the prepared dyes were confirmed using elemental analysis, 1HNMR spectroscopy, mass spectrometry, and IR. The synthesized dyes were applied to polyester and nylon fabrics using different dyeing techniques: high temperature- high pressure, and ultrasonic dyeing methods. The highest K/S values for all investigated dyes were achieved usinga high temperature-high pressure dyeing technique. Also, the color reflectance of all synthesized dyes with different dyeing shades (1%, 2%, and 3%) was obtained. The fastness properties of the dyed samples using the investigated dyes showed good color fastness toward light, washing, rubbing, and perspiration fastness. The presence of a chromene moiety and Schiff base in the investigated dyes promotes a higher antimicrobial activity on nylon and polyester fabrics against all tested bacteria (E. coli gram-negative and Staphylococcus aureus gram-positive) and two fungi, Aspergillus Niger and Candida albicans. [ABSTRACT FROM AUTHOR]

Recently, there has been increased attention to hydrocarbonoclastic bacteria in the plastisphere. One particular genus, Alcanivorax, is reported in the biodegradation of several polymers in the literature. In this study, we further explored the role of Alcanivorax in the early colonization of poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBH), nylon 6/69, and a novel plastic B4PF01. Starting from enrichments of a one‐year experiment with a maximum relative abundance of 58.8% of Alcanivorax, two parallel experiments were set up. One experiment followed growth and activity during the first 21 days of plastic incubations, and the other followed the same parameters on the different material fractions of the plastics, such as leachables and pure polymer. For all plastic types, the highest microbial growth was associated with the total plastics compared to the other material fractions. A relative abundance of 62.7% of Alcanivorax in the nylon 6/69‐enriched community was observed. This, combined with data on activity, suggests that nylon 6/69 is potentially degraded by this genus. Two isolates were obtained, closely related to A. borkumensis SK2 and Alcanivorax sp. DG881. The activity and growth of the isolates as axenic cultures resemble their abundance in the community. In conclusion, this study contributes to the knowledge of the role of Alcanivorax in plastic‐enriched communities. [ABSTRACT FROM AUTHOR]

Common mycorrhizal networks (CMNs) can link multiple plants and distribute nutrients among them. However, how parasitic plants regulate the carbon and nutrient exchange between CMNs and the linked plants is unknown. Thus, we conducted a container experiment with two Trifolium pratense grown in two plastic cores and connected only by CMNs using a 25‐μm nylon fabric in each container. Host T. pratense was parasitized or not parasitized by Cuscuta gronovii. CMNs were left intact or broken by rotating the cores with the host or neighboring T. pratense. The dual 15N and 13C labeling method was used to evaluate the N distributed by CMNs to the host and neighboring T. pratense and the recently fixed C from the host and neighboring T. pratense to CMNs. The results showed that CMNs distributed more 15N to unparasitized neighboring T. pratense than the parasitized host T. pratense. Moreover, the unparasitized neighboring T. pratense provides more recently fixed C to CMNs than the parasitized host T. pratense. These results revealed that the parasite regulated C and nutrient exchange between CMNs and the linked plants following the reciprocal rewards rule. Moreover, this study highlights the importance of parasitic plants in the regulation of mutualistic interactions in ecological webs. [ABSTRACT FROM AUTHOR]

This study analyses the microplastics in the sediment of areas surrounding shipwrecks on the Continental Shelf of Pernambuco, North eastern Brazil. The sediment collection was carried out around six wrecks. Flotation methodology was used to separate the possible microplastics from the sediment. Microplastics were classified by type and colour. Of the 6 shipwrecks analysed, 413 microplastic items were identified, with nylon fibre predominating. Fibres of blue colour were the most frequent, totalling 48.4%. The presence of microplastics in shipwrecks shows that this environment, even far from the coast, is subject to human activity. The accumulation of microplastics in the sediments surrounding the shipwrecks may pose a risk to marine life. [ABSTRACT FROM AUTHOR]

This study is aimed at investigating the crystallization kinetics of two structurally related polymers, Nylon 6,6 (PA66) and Nylon 11 (PA11), by differential scanning calorimetry (DSC) in the scope of a logistic-based model using a model fitting approach. By this method, the values of the rate parameters for each specific temperature are obtained from fitting all points of the crystallization exotherm that were accurately recorded at that temperature. This method differs from Arrhenius-based model fitting approaches, in which the initial and final parts of the exotherm do not usually match the shape of Arrhenius-based models and are therefore discarded for fitting. Furthermore, in other kinetic approaches that fall outside the scope of this article, kinetic parameters are typically obtained from specific points in the crystallization exotherm, and good fits cannot generally be obtained nor is that the goal of those approaches. The DSC curves of both polymers obtained at different temperatures are analysed to determine the crystallization kinetics. One of the most insightful parameters of the model is the crystallization rate. Its dependence on temperature is analysed for both polymers and compared to others. The other parameters can also help to better understand some of the crystallization features of these polymers. In addition, the information retrieved from this study can be useful to adjust processing conditions. [ABSTRACT FROM AUTHOR]

Objectives: For nerve injuries, not amendable to tensionless epineural coaptation of the nerve, autografts are the preferred treatment. Although absorbable sutures are not recommended for nerve repair, there is no evidence that non-absorbable sutures are superior to absorbable sutures. This study aims to assess the effectiveness of non-absorbable monofilament nylon sutures, absorbable monofilament vicryl sutures, and fibrin glue when used for nerve grafting. Methods: Lewis rats (N = 32) were subjected to a sciatic nerve transection and randomly assigned to a group: graft with Nylon, graft with Vicryl, graft with Fibrin Glue, or no graft. Motor function, sensory function, and thermal pain were assessed during a 12-week recovery period, and immunohistochemistry was used to assess macrophage response. Results: At 12 weeks, the Vicryl and Nylon groups had significantly larger ankle angles at to lift off, which is a measure of motor function, compared to injured controls (p < 0.05). Grafted rats displayed no difference in thermal response but hypersensitivity to mechanical stimuli compared to the uninjured hindlimb. The Nylon, Vicryl, and Fibrin Glue groups all had significantly less atrophy of the gastrocnemius muscle compared to injured controls (p < 0.0001). In the Fibrin Glue group, 3/9 grafts did not incorporate. The Nylon group had significantly less (p = 0.0004) axon growth surrounding the suture holes compared to the Vicryl group. There were no differences in the axon counts, motor neurons, or sensory neurons between all grafted rats. Conclusions: These results demonstrate that vicryl sutures work just as well as nylon for nerve recovery after injury and grafting. [ABSTRACT FROM AUTHOR]

The article used sebacic acid and meta phenylenediamine as raw materials, and explored the synthesis process of nylon MXD10 through high-temperature and high-pressure melt polymerization. On this basis, the performance of the synthesized semi-aromatic nylon MXD10 was characterized. The structure of nylon MXD10 was analyzed using Fourier transform infrared spectroscopy. The thermal properties of nylon MXD10 were analyzed by differential scanning calorimetry and thermogravimetric analyzer. The results showed that the melting temperature and crystallization temperature of the synthesized nylon MXD10 were 175 °C and 117 °C, respectively. Thermal decomposition was a one-step decomposition method. Non isothermal crystallization kinetics analysis was also conducted on nylon MXD10, and the non isothermal crystallization kinetics of semi-aromatic nylon MXD10 were studied comprehensively through the Jeziorny equation and Mo Zhishen method. The results indicate that the crystal growth of semi-aromatic nylon MXD10 is two-dimensional, and the crystallization temperature decreases with the increase of cooling rate. The activation energy is -981.625 kJ/mol. [ABSTRACT FROM AUTHOR]