Ultra-high molecular weight polyethylene (UHMWPE) possesses distinctive properties, but has an extremely low melt flow rate (MFR) of about zero, which makes it unsuitable for processing by standard methods for polymers. The aim of this paper was to investigate the tribological properties of two-component UHMWPE-based composites with different content of isotactic PP. The composites were fabricated by three methods: a) hot pressing of the powder mixtures; b) hot compression of granules; and c) 3D printing (FDM). It was shown that the UHMWPE-based composites obtained by extrusion compounding (hot compression of granules and 3D printing) in terms of the mechanical and tribological properties (wear resistance, the friction coefficient, Young's modulus, and yield strength) were superior to the ones manufactured by hot pressing of the powder mixtures. The most effective was the ‘UHMWPE+20% PP’ composite in terms of maintaining high tribological and mechanical properties and the necessary melt flow rate (MFR) in a wide range of loads. It was recommended as a feedstock for additive manufacturing of complex-shaped products (joint components) for friction units in orthopedics.

For many years, 3D Printing technologies have created significant advancements in the fields of engineering and healthcare. 4D printing is also introduced, which is the advanced version of 3D printing. The process of 4D printing is when a printed 3D object becomes another structure due to the influence of outside energy inputs such as temperature, light, or other environmental stimuli. This technology uses the input of smart materials, which have the excellent capability of shape-changing. The self-assembly and programmable material technology aim to reimagine building, production, assembly of products, and performance. 4D printing is applied in various sectors such as engineering, medicine, and others. 4D printed proteins could be a great application. With this new dimension, 3D printed objects can change their shape by themselves over the influence of external stimuli, such as light, heat, electricity, magnetic field, etc. This paper discussed a brief about 4D printing technology. Various characteristics of 4D Printing for enhancing the manufacturing domain, its development, and applications are discussed diagrammatically. Conceptualised the Work Process Flow for 4D Additive Manufacturing and finally identified ten major roles of 4D printing in the manufacturing field. Although reversible 4D Printing itself is a fantastic development, it is innovative, and it employs durable and accurate reversal material during the shapeshift. It helps us create complicated structures that cannot be accomplished easily by traditional manufacturing technologies. It seems to be a game-changer in different industries by depending on natural factors instead of energy and changes the way to produce, develop, bundle, and ship goods entirely.

Additive manufacturing (AM) produces a complex shaped product from its data, layer by layer, with high precision and much less material wastage. As compared to the conventional manufacturing process, there are many positive environmental advantages of additive manufacturing technologies. Most importantly, there is less waste of raw material and the use of new and smart materials. It appears to concentrate on the output of a component on lesser material waste, energy usage, and machine emissions. There is a need to study the environmental sustainability of additive manufacturing technologies and their applications. As more businesses aim to strengthen their eco-footprint, sustainability in AM is gaining momentum. Visionary leaders of the industry are continually challenging their employees to find new ways to reduce waste, improving their workforce's manufacturing environment, and find innovative ways to use new materials to become more sustainable. The growth in value-added components, goods, and services has resulted from these initiatives. This paper discusses the significant benefit of additive manufacturing to create a sustainable production system. Finally, the paper identifies twelve major applications of AM for sustainability. Although additive manufacturing and technological dominance are being established with crucial industries, their sustainability advantages are visible in the current manufacturing scenario. The main goal is to identify the environmental benefits of additive manufacturing technologies over conventional manufacturing. Industries can now decide on suitable technologies to meet environmental goals.

With the ever-growing demand for 5G networks and the promise of real-time, mission-critical applications, the advanced antennas with high-bandwidth and highly reliable connectivity are urgently needed. 5G networks primarily operate in two areas of spectrum below 6 GHz (known as sub 6) and millimeter wave, which are much higher than the working frequency of 4G cellular networks, thus the previously used materials and integration techniques need to be updated accordingly. In this sense, liquid crystal polyesters (LCP) have been considered as ideal high performance microwave/millimeter wave (mm-wave) substrate and packing materials due to their outstanding properties. More specifically, the LCP normally exhibit good thermal stability, low water absorption, stable dielectric constant and loss tangent in millimeter wave frequency range, which leads to the increasing research interests of LCP for 5G devices application in both academia and industrial fields. However, the review articles focusing on the chemistry and materials aspects of LCP intended for 5G application are unexpectedly limited. In this article, we will summarize the research progress of LCP materials used in 5G networks in the view of polymer science and engineering. More specifically, the polymerization, chemical structure, aggregated state, properties, modification and processing of typical LCP are reviewed, which would be useful for promoting practical application of the LCP in key devices of 5G networks.

With the rise of the fifth-generation (5G) mobile communication, electromagnetic interference (EMI) and radiation become progressively serious toward electronic devices and human health, resulting in an increasing demand for EMI shielding materials. Polymer-based EMI shielding materials have drawn considerable attention in relevant industries and academia owing to their low density, easy processing, and superior flexibility. In this review, we systematically discuss the development of polymer-based shielding materials fabricated by using polymers as matrices and precursors. The architecture design of polymer composites is emphasized including homogenous structure, porous structure, laminated structure, and segregated structure. Specific attention is also given to the polymer derivatives from synthetic and natural polymers. Finally, we summarize the recent advancements and our guidelines for the development of polymer-based EMI shielding materials in the 5G era.

High-performance polymer materials with low dielectric constant and low dielectric loss have been widely used in high-speed communication network. This review briefly introduces several common polymer materials, including polyimides, poly(benzoxazole)s, poly(aryl ether)s, poly(tetrafluoroethylene), and various porous polymers. Moreover, the preparation technology, various properties and applications of common low-dielectric polymers are discussed. Based on the desired properties and requirements for applications as low dielectric materials, the possibility of further development of porous polymer materials is discussed.