The textile and fashion industries account for a significant part of global business. Textile wet processing (TWP) is a crucial stage in textile manufacturing. It imparts aesthetics as well as functional appeal on the textile fabric and ultimate products. Nevertheless, it is considered as one of the most polluting industries and threatens sustainability. There have been different approaches to transform this polluting industry to a sustainable industry. Many researchers have found this challenging, as sustainable, eco-friendly, green or cleaner wet processing might not be always applicable and relevant from the perspective of industrial applications. The present work helps us understand the current state of research of cotton-based textile processes including proposed sustainable approaches. It also examines the achievement of the degree of sustainability of those proposed processes with the lens of the triple bottom line (TBL) framework, identifies existing limitations, and suggests future research scopes that might pave ways for young researchers to learn and undertake new experimental and theoretical research.

The present research investigated previously unexplored attributes of 3D printed continuous fiberglass reinforced Nylon composites, Drop-weight and pendulum (Charpy and Izod) impact resistance including their failure mechanisms with a view to assessing their suitability for prospective high-performance applications such as aerospace, automobile and building industries. The composites were printed with different cellular structures (triangular, hexagonal, rectangular and solid) and three distinct fiber orientations (0/0/0/0, 0/90/0/90 and 0/45/90/-45). Results of the impact assessment of the developed composites exhibited substantial performance when compared to traditional 3D orthogonal plain-woven composites indicating 3D printing process as a promising composite fabrication technology. The effect of fiber orientation was very dominant towards dictating mechanical properties; cross-lay samples (0/90/0/90) absorbed the highest Drop-weigh impact energy followed by quasi-isotropic (0/45/90/-45) and unidirectional (0/0/0/0) composites, while the highest pendulum impact energy was showed by unidirectional composites, followed by cross-lay and quasi-isotropic samples. Incorporation of cellular structure had some effect on the properties measured and composite weight reduction; however, relative contribution of different structures was confounding associating a lot of factors that warn further research.

Three-dimensional printing (3DP) is at the forefront of the disruptive innovations adding a new dimension in the material fabrication process with numerous design flexibilities. Especially, the ability to reinforce the plastic matrix with nanofiber, microfiber, chopped fiber and continuous fiber has put the technology beyond imagination in terms of multidimensional applications. In this technical paper, fiber and polymer filaments used by the commercial 3D printers to develop fiber-reinforced composites are characterized to discover the unknown manufacturing specifications such as fiber–polymer distribution and fiber volume fraction that have direct practical implications in determining and tuning composites’ properties and their applications. Additionally, the capabilities and limitations of 3D printing software to process materials and control print parameters in relation to print quality, structural integrity and properties of printed composites are discussed. The work in this paper aims to present constructive evaluation and criticism of the current technology along with its pros and cons in order to guide prospective users and 3D printing equipment manufacturers on improvements, as well as identify the potential avenues of development of the next generation 3D printed fiber-reinforced composites.

Recent advancements in 3D printing involve reinforcing the polymer matrix with high-strength fibers offer improved mechanical properties over unreinforced polymeric materials. The fiber-reinforcement offers a great potential to customize fiber-reinforced 3D printed polymer composites for complex shapes and high-performance parts for diverse end use applications. The advance capabilities also allow to vary the 3D printed composite weight without compromising the mechanical properties. The aim of this research was to investigate unique macrostructures of 3D printed samples developed by varying the printing parameters, and their influence on the tensile behavior. Samples developed for this study comprised of nylon matrix reinforced with continuous fiberglass with three varying fiber orientations and four different infill geometries. Tensile properties of the unreinforced and reinforced 3D printed samples were evaluated to investigate the impact of fiber orientation and infill geometries and further benchmarked with traditional 3D orthogonal woven (3DOW) composites. The results indicated that the tensile properties due to fiber orientation mainly dictated the tensile properties more than the cellular structure. The analyses from this study showed that the macrostructure (hence tensile properties) of 3D printed specimens were directly related to the printing parameters that include fiber amount and orientation, void formation and the bonding between individual raster/layers.

Fiber-reinforced 3D printing technology offers significant improvement in the mechanical properties of the resulting composites relative to 3D printed (3DP) polymer-based composites. However, 3DP fiber-reinforced composite structures suffer from low fiber content compared to the traditional composite, such as 3D orthogonal woven preforms solidified with vacuum assisted resin transfer molding (VARTM) that impedes their high-performance applications such as in aerospace, automobile, marine and building industries. The present research included fabrication of 3DP fiberglass-reinforced nylon composites, with maximum possible fiber content dictated by the current 3D printing technology at varying fiber orientations (such as 0/0, 0/90, ±45 and 0/45/90/−45) and characterizing their microstructural and performance properties, such as tensile and impact resistance (Drop-weight, Izod and Charpy). Results indicated that fiber orientation with maximum fiber content have tremendous effect on the improvement of the performance of the 3DP composites, even though they inherently contain structural defects in terms of voids resulting in premature failure of the composites. Benchmarking the results with VARTM 3D orthogonal woven (3DOW) composites revealed that 3DP composites had slightly lower tensile strength due to poor matrix infusion and voids between adjacent fiber layers/raster, and delamination due to lack of through-thickness reinforcement, but excellent impact strength (224% more strong) due to favorable effect of structural voids and having a laminated structure developed in layer-by-layer fashion.