Hasil untuk "Textile bleaching, dyeing, printing, etc."

Ainhoa Sánchez-Martínez, Marilés Bonet-Aracil, Ignacio Montava et al.

The textile industry generates significant volumes of waste, making the development of reliable methods to evaluate biodegradability a pressing need. While standardised protocols exist for plastics, no specific methodologies have been established for textiles, and the quantification of non-degraded residues is commonly based on mass loss: a measurement that is prone to recovery errors. This study investigated the biodegradation of cotton, polyester, and cotton/polyester blend fabrics in soil under thermophilic conditions using a combined methodological approach. Carbon mineralisation was quantified through a respirometric assay that was specifically adapted for textile substrates, while residual solid fractions were assessed in situ by X-ray microtomography (micro-CT), thus avoiding artefacts associated with sample recovery. Complementary analyses were performed using SEM and FTIR to characterise morphological and chemical changes. Results showed substantial biodegradation of cotton, negligible degradation of polyester, and intermediate behaviour for the cotton/polyester blend. Micro-CT enabled the visualisation of fibre fragmentation and the quantification of the residual. The integration of respirometric, imaging, and spectroscopic techniques provided a comprehensive assessment of textile biodegradability. This study highlights the potential of micro-CT as a non-destructive tool to improve the accuracy and robustness of textile biodegradability assessment by enabling direct quantification of the residual solid fraction that can support future LCA studies and the development of standardised protocols for textile biodegradability.

M. A. Litvinov, Ya. V. Kazakov, N. P. Midukov et al.

Ioanna Mitropoulou, Amir Vaxman, Olga Diamanti et al.

We present a method to fabricate double shell structures printed in trans-versal directions using multi-axis fused-deposition-modeling (FDM) robot-ic 3D printing. Shell structures, characterized by lightweight, thin walls, fast buildup, and minimal material usage, find diverse applications in pro-totyping and architecture for uses such as façade panels, molds for concrete casting, or full-scale pavilions. We leverage an underlying representation of transversal strip networks generated using existing methods and propose a methodology for converting them into printable partitions. Each partition is printed separately and assembled into a double-shell structure. We out-line the specifications and workflow that make the printing of each piece and the subsequent assembly process feasible. The versatility and robust-ness of our method are demonstrated with both digital and fabricated re-sults on surfaces of different scales and geometric complexity.

Pauline Rothmann-Brumm, Steven L. Brunton, Isabel Scherl

Hydrodynamic pattern formation phenomena in printing and coating processes are still not fully understood. However, fundamental understanding is essential to achieve high-quality printed products and to tune printed patterns according to the needs of a specific application like printed electronics, graphical printing, or biomedical printing. The aim of the paper is to develop an automated pattern classification algorithm based on methods from supervised machine learning and reduced-order modeling. We use the HYPA-p dataset, a large image dataset of gravure-printed images, which shows various types of hydrodynamic pattern formation phenomena. It enables the correlation of printing process parameters and resulting printed patterns for the first time. 26880 images of the HYPA-p dataset have been labeled by a human observer as dot patterns, mixed patterns, or finger patterns; 864000 images (97%) are unlabeled. A singular value decomposition (SVD) is used to find the modes of the labeled images and to reduce the dimensionality of the full dataset by truncation and projection. Selected machine learning classification techniques are trained on the reduced-order data. We investigate the effect of several factors, including classifier choice, whether or not fast Fourier transform (FFT) is used to preprocess the labeled images, data balancing, and data normalization. The best performing model is a k-nearest neighbor (kNN) classifier trained on unbalanced, FFT-transformed data with a test error of 3%, which outperforms a human observer by 7%. Data balancing slightly increases the test error of the kNN-model to 5%, but also increases the recall of the mixed class from 90% to 94%. Finally, we demonstrate how the trained models can be used to predict the pattern class of unlabeled images and how the predictions can be correlated to the printing process parameters, in the form of regime maps.

K. Mawas, M. Maboudi, M. Gerke

Given the substantial growth in the use of additive manufacturing in construction (AMC), it is necessary to ensure the quality of printed specimens which can be much more complex than conventionally manufactured parts. This study explores the various aspects of geometry and surface quality control for 3D concrete printing (3DCP), with a particular emphasis on deposition-based methods, namely extrusion and shotcrete 3D printing (SC3DP). A comprehensive overview of existing quality control (QC) methods and strategies is provided and preceded by an in-depth discussion. Four categories of data capture technologies are investigated and their advantages and limitations in the context of AMC are discussed. Additionally, the effects of environmental conditions and objects' properties on data capture are also analyzed. The study extends to automated data capture planning methods for different sensors. Furthermore, various quality control strategies are explored across different stages of the fabrication cycle of the printed object including: (i) During printing, (ii) Layer-wise, (iii) Preassembly, and (iv) Assembly. In addition to reviewing the methods already applied in AMC, we also address various research gaps and future trends and highlight potential methodologies from adjacent domains that could be transferred to AMC.

Jiabao Wu, Xinpeng Chen, Aijing Li et al.

Synthetic dyes are prone to water pollution during use, jeopardizing biodiversity and human health. This study aimed to investigate the adsorption and photocatalytic assist potential of sodium lignosulfonate (LS) in in situ reduced silver nanoparticles (AgNPs) and chitosan (CS)-loaded silver nanoparticles (CS-LS/AgNPs) as adsorbents for Rhodamine B (RhB). The AgNPs were synthesized by doping LS on the surface of chitosan for modification. Fourier transform infrared (FT-IR) spectrometry, energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to confirm the synthesis of nanomaterials. The adsorption and photocatalytic removal experiments of RhB were carried out under optimal conditions (initial dye concentration of 20 mg/L, adsorbent dosage of 0.02 g, time of 60 min, and UV power of 250 W), and the kinetics of dye degradation was also investigated, which showed that the removal rate of RhB by AgNPs photocatalysis can reach 55%. The results indicated that LS was highly effective as a reducing agent for the large-scale production of metal nanoparticles and can be used for dye decolorization. This work provides a new catalyst for the effective removal of dye from wastewater, and can achieve high-value applications of chitosan and lignin.

Michael Danner, Elena Brake, Gabriela Kosel et al.

This paper introduces an AI-assisted pattern generator, aimed to simplify garment design by flattening the pattern creation in an automated process from 3D scans for users without knowledge of conventional pattern construction. This garment tool plug-in computerizes the development of scanned persons into 3D shell surface meshes, which are automatically unwrapped into 2D patterns, streamlining the traditionally complex aspects of garment design for novices. The process uses advanced AI algorithms to facilitate the conversion of 3D scans into usable patterns. Machine learning adapts to different garment styles (close-fitting, regular fit and loose-fitting), ensuring a broad applicability, while customization options allow a precise adaption to individual body measurements. This AI-assisted tool enables a wider audience to generate customized garment creation.

مجید میرزایی, طیبه محبی

توسعه اخیر نیروگاه بادی دریایی (OWPDs) الزامات بالایی را برای مواد پوشش محافظ در برابر خوردگی و فرسایش ایجاد می‏کند. فرسایش لبه پیشرو (LE) پره‏های توربین بادی یکی از آسیب‏های رایج است که باعث کاهش تولید سالانه انرژی به ویژه در مزارع توربین بادی می‏شود. این فرسایش می‏تواند ناشی از باران، شن و ذرات جامد باشد.  همچنین قسمت‏های فلزی نیروگاه بادی دریایی در معرض محیط حاوی یون کلرید، دچار خوردگی حفره‏ای می‏شوند. پوشش‏های هیبریدی آلی- معدنی (OIHCs) به دلیل خواص برتر خود با ترکیب هر دو جزء معدنی و آلی مورد توجه بسیار زیادی قرار گرفته است. تکنیک سل-ژل روشی مناسب برای تولید پوشش‏های لایه نازک است که می‏تواند از اجزای نیروگاه بادی دریایی در برابر فرسایش و خوردگی محافظت کرده و در عین حال تأثیر ناچیزی بر وزن اجزای نیروگاه به خصوص پره‏های توربین داشته باشد. این مقاله مروری، استراتژی‏های اخیر برای پوشش‏های محافظ‌ OWPD‏ها را خلاصه می‏‏‏‏‏‏‏‏‏‏کند و چشم‏انداز توسعه OIHC‏ها را به عنوان مواد پوششی برای OWPD‏ها ارائه می‏دهد.

Muriel Mauron, Lucie Castens Vitanov, César Michaud et al.

Inkjet printing technology achieves the precise deposition of liquid-phase materials via the digitally controlled formation of picoliter-sized droplets. Beyond graphical printing, inkjet printing has been employed for the deposition of separated drops on surfaces or the formation of continuous layers, which allows to construct materials gradients or periodic features that provide enhanced functionalities. Here, we explore the use of multinozzle, drop-on-demand piezoelectric inkjet technology for the manufacturing of mechanochromic materials, i.e., materials that change their color or fluorescence in response to mechanical deformation. To accomplish this, suitable polyurethane polymers of differing hardness grades were tested with a range of organic solvents to formulate low-viscosity, inkjet-printable solutions. Following their rheological characterization, two solutions comprised of "soft" and "hard" polyurethanes were selected for in-depth study. The solutions were imbibed with a mechanochromic additive to yield fluorescent inks, which were either dropcast onto polymeric substrates or printed to form checkerboard patterns of alternating hardness using a lab-built, multimaterial inkjet platform. Fluorescence imaging and spectroscopy were used to identify different hardness grades in the dropcast and printed materials, as well as to monitor the responses of these gradient materials to mechanical deformation. The insights gained in this study are expected to facilitate the development of inkjet-printable, mechanochromic polymer materials for a wide range of applications.

Sammy Florczak, Gabriel Groessbacher, Davide Ribezzi et al.

We introduce Generative, Adaptive, Context-Aware 3D Printing (GRACE), a novel approach combining 3D imaging, computer vision, and parametric modelling to create tailored, context-aware geometries using volumetric additive manufacturing. GRACE rapidly and automatically generates complex structures capable of conforming directly around features ranging from cellular to macroscopic scales with minimal user intervention. We demonstrate its versatility in applications ranging from synthetic objects to biofabrication, including adaptive vascular-like geometries around cell-laden bioinks, resulting in improved functionality. GRACE also enables precise alignment of sequential prints, in addition to the detection and overprinting of opaque surfaces through shadow correction. Compatible with various printing modalities, GRACE transcends traditional additive manufacturing limitations, opening new avenues in tissue engineering and regenerative medicine.

Hua Wang, Hafeezullah Memon

Robert Kaminszky, Dorin Avram, Magdalena Simona Fogorasi et al.

Yarn’s hairiness represents a continuous challenge for spinning technologies. To keep this aspect under control, an almost perfect combination between the construction and performance of the machines, the control of the technological processes through appropriate settings, and the experience of the producers are required. As a consequence, the researchers were preoccupied to adapt or modify the ring frame to produce yarns with a lower degree of hairiness. Spinning triangles as a very demanding area exert a crucial impact both on the distribution of fiber tension and their spatial location in the staple yarn structure. Our study encompasses yarn hairiness reduction employing a device composed of two bars. Various combinations of spindle speeds and contact angles between yarns and bars were tested to examine their effects on yarn hairiness. The study was completed with the optimization of technological parameters using a central, composite, rotating program with two independent variables (spindle speed and contact angle) to establish mathematical models and optimize technological parameters for the reduction of hairiness. The effectiveness and efficiency of this device consist of the easy execution and installation on the existing machines in spinning mills without any constructive adjustments and additional energy consumption.

Eleonora Bianca, Francesca Dotti, Ada Ferri

This study investigates the thermal insulation and moisture management of three types of mountaneering boots and simulated hiking activities under controlled environmental conditions with two elite athletes. Temperature and humidity were determined with six wireless probes placed on the most exposed parts of the foot (hallux, middle toe, little toe, dorsum, ankle and sole). Thermal images were taken to record the thermal insulation of each sample. Methodologically, the study aims to simulate every movement and activity of alpinism in order to realistically evaluate the conditions of use of this kind of footwear (also taking into account the lacing pressure exerted on the foot). Based on the results obtained, in a further step it will be possible to define the best solution in terms of combination of materials by creating a comfort scale for hiking boots.

Venkata Chalapathi K, M. N. Prabhakar, Jung-Il Song

This paper presents a novel plant-derived core-shell fiber carrier that can be used in self-healing applications. The study used abaca fiber lumens as a self-healing carrier for the first time. The fibers were characterized under SEM at different positions to know the lumen structure and achieved a 39.19% lumens fraction and 16.13 µm lumen diameter. Healing resins were embedded in the lumens using modified VARTM. The core was confirmed using FESEM-EDX. Thermal degradation was determined via TGA under a nitrogen atmosphere. The mechanical and self-healing properties, as well as a single-fiber tensile test, were conducted with a cell load of 5 kgf. The healing resin (VE-CN)-embedded fibers showed a strength improvement of 14.78% compared with the strength of pure abaca fibers. The improved strength is attributed to the reorientation of the crystalline cellulose in the tensile direction. Additionally, some of the tensile-fractured fibrils self-healed after 24 h and showed a restored strength of 100.71 MPa. The restored strength explains that the fiber lumens are the potential to carry a healing resin and release upon the damage.

Abdellaoui Olfa, Harizi Taoufik, Zouari Riadh et al.

According to environmental issues and guidelines, increasing efforts are being focused on reducing the harmful impact of textile wastes either by lowering the use of chemicals or by recycling wastes into new products to give them a new life cycle. In this paper, we investigate the physical and chemical properties of wool wastes coming from tanning industry, where the process of pulling the wool from the hide is based on chemical processes. These so-called “’Pulled wool’” properties are compared to virgin raw wool obtained from the same pelt, to evaluate the degradation of the fiber induced by the chemicals. SEM observations indicate that the pulled wool fiber surface appeared rougher, and the scales appeared to have been affected. Based on the X-ray diffraction, the crystallinity of the pulled fibers appeared to have been slightly reduced. Attenuated ATR-FTIR analyses indicated some changes in chemical composition. HPLC tests showed an apparent increase in the amount of cystic acids indicating damage of some macromolecular chains crosslinking. Thus, some properties appeared significantly affected during the chemical unhairing process. Based on these characteristics of pulled wool, potential applications to valorize it could be suggested, as we show that it remains suitable for conventional textile processes.

Arjunsing Girase, Donald Thompson, Robert Bryan Ormond

The National Fire Protection Association (NFPA) 1851 document provides guidelines for firefighters on the care and maintenance of their PPE, including decontamination practices. Firefighters are exposed to various toxic chemicals during fire suppression activities, making effective decontamination crucial for their safety. This study evaluated the efficacy of different washing parameters, including temperature, time, and surfactants, on cleaning outer-shell material contaminated with nine targeted compounds from three different functional groups: phenols, polycyclic aromatic hydrocarbons (PAHs), and phthalates. The study was conducted on both bench-scale and full-scale levels, with contaminated swatches washed in a water shaker bath in the bench-scale evaluation and full-sized washer extractors used in the full-scale evaluation. The results showed that bench-scale washing demonstrated similar trends in contaminant removal to full-scale washing. Importantly, the study highlighted the complexity of removing fireground contaminants from the personal protective ensemble (PPE). The findings of this study have practical implications for the firefighting industry as they provide insight into the effectiveness of different washing parameters for PPE decontamination. Future studies could explore the impact of repeated washing on PPE and investigate the potential for developing more efficient decontamination strategies. Ultimately, the study underscores the importance of ongoing efforts to ensure the safety of firefighters, who face significant occupational hazards.

Marios-Nektarios Stamatopoulos, Avijit Banerjee, George Nikolakopoulos

The future of 3D printing utilizing unmanned aerial vehicles (UAVs) presents a promising capability to revolutionize manufacturing and to enable the creation of large-scale structures in remote and hard- to-reach areas e.g. in other planetary systems. Nevertheless, the limited payload capacity of UAVs and the complexity in the 3D printing of large objects pose significant challenges. In this article we propose a novel chunk-based framework for distributed 3D printing using UAVs that sets the basis for a fully collaborative aerial 3D printing of challenging structures. The presented framework, through a novel proposed optimisation process, is able to divide the 3D model to be printed into small, manageable chunks and to assign them to a UAV for partial printing of the assigned chunk, in a fully autonomous approach. Thus, we establish the algorithms for chunk division, allocation, and printing, and we also introduce a novel algorithm that efficiently partitions the mesh into planar chunks, while accounting for the inter-connectivity constraints of the chunks. The efficiency of the proposed framework is demonstrated through multiple physics based simulations in Gazebo, where a CAD construction mesh is printed via multiple UAVs carrying materials whose volume is proportionate to a fraction of the total mesh volume.

Chintan Vyas, Mangilal Choudhary

The industrial application of non-thermal plasma has been a research field in the last few years. One of the potential applications of non-thermal plasma is in treating dye effluents of textiles industries which are considered as one of the environmental pollutants. Before scaling up plasma technology at the industrial level, it is required to understand the interaction of non-thermal plasma with a synthetic dye-containing solution in laboratory experiments. A detailed comparative study of MB dye degradation using an atmospheric pressure air plasma (corona discharge) source is carried out in this report. The results are qualitatively discussed in line with the available theoretical and experimental background of plasma-water interaction.

Yijia Wu, Zilin Dai, Haotian Liu et al.

Pneumatic soft robots are typically fabricated by molding, a manual fabrication process that requires skilled labor. Additive manufacturing has the potential to break this limitation and speed up the fabrication process but struggles with consistently producing high-quality prints. We propose a low-cost approach to improve the print quality of desktop fused deposition modeling by adding a webcam to the printer to monitor the printing process and detect and correct defects such as holes or gaps. We demonstrate that our approach improves the air-tightness of printed pneumatic actuators without fine-tuning printing parameters. Our approach presents a new option for robustly fabricating airtight, soft robotic actuators.

Shiwei Li, Heng Quan, Li Ai et al.

Superhydrophobic textiles have attracted great interest due to their special functions and wide applications. However, it is still a huge challenge to construct a durable superhydrophobic coating for large-scale applications due to the complicated process and high cost. In this work, a facile two-step method was developed to construct superhydrophobic cotton fabric with fluorine-free treatment. The cotton fabrics were treated with modified nano SiO2 to construct rough surfaces. Then, the silicone oil was introduced into the surface of the cotton fabric to form superhydrophobic cotton fabric. The results showed that the modified nano SiO2 and silicone oil were stably fixed on the fiber surface. The static water contact angle test showed that contact angle of the modified cotton fabric was 158°, indicating excellent superhydrophobic properties. Furthermore, the self-cleaning and anti-pollution test results showed that the superhydrophobic cotton fabric possessed good self-cleaning and antifouling performance. This superhydrophobic fabric avoids the use of fluoropolymers and reduces the harm to humans and environment, showing a wide range of applications.