Filler materials are considered added value (volume) to composite materials. The addition of filler materials leads to altering the material characteristics. Nowadays, there has been a notable increase in bio-based materials in polymers and polymer composites. In this regard, agricultural wastes (low-cost renewable substrates) are used as filler content to prepare bioplastic composites, as they are available plenty in quantity and economical in price. Bioplastics composite samples are compounded by adding different amounts of eggshell powder and walnut shell powder in weight proportion to the plasticized PLA. The plasticization is realized with 5 wt.% of Epoxidized Soybean Oil. The prepared bioplastic granules are further processed by injection molding to dog bone-shaped samples subjected to different mechanical, thermal, and optical microscopy tests. Mechanical tests such as Tensile, Charpy Impact, and Flexural tests yielded decreased properties compared to virgin PLA. However, the properties of plasticized PLA–ES composite showed better results than plasticized PLA–WS composite.

Plastic is being used increasingly in daily life. Most of it is not recyclable, and the remaining plastic cannot be used or decomposed. This causes increased plastic waste, contributing to global warming due to thermal recycling. The major objective of this research was to utilise the maximum plastic waste possible to manufacture bricks that compete with the properties of conventional bricks without affecting the environment and the ecological balance. A balanced mixture of high-density polyethylene (HDPE), quartz sand, and some additive materials, such as bitumen, was used to produce these bricks. Various tests were performed to assess the bricks’ quality, such as compression, water absorption, and efflorescence tests. These bricks had a compression strength of 37.5 MPa, which is exceptionally strong compared to conventional bricks. The efflorescence and water absorption tests showed that the bricks were nearly devoid of alkalis and absorbed almost no water. The obtained bricks were light in weight and cost-effective compared to conventional bricks.

Contrary to other polymer processing methods, additive manufacturing processes do not require any pressure during the consolidation of layers. This study investigates the effect of high ambient pressure on the consolidation of layers during the FDM process and their analysis of mechanical properties. An experimental setup was arranged, consisting of a 3D printer integrated into a customized Autoclave, to achieve high strength properties for 3D printed parts as like injection-molded specimens. The autoclave can maintain 135 bar of pressure and a maximum temperature of 185 °C. 3D printing with PLA was carried out at 0 bar, 5 bar, and 10 bar. Tensile, flexural, and Charpy tests were conducted on printed specimens, and the effect of pressure and temperature on 3D-printed samples were analyzed. It could be shown that autoclave preheating before printing and autoclave pressure during printing improves the consolidation of layers immensely. The pressure inside the autoclave provokes a more intimate contact between the layer surfaces and results in higher mechanical properties such as yield strength, Young’s modulus, and impact strength. The properties could be raised 100%.

Carbon fiber reinforced polymers (CFRPs) have spread to a wide range of industries in recent decades, including the automobile, aeronautics, and space industries. Recently, the emergence of new requirements for improved properties and features has become one of the major drivers of the introduction of innovative methodologies and process optimization. In this study, the effect of nanomaterials on the behavior of carbon fiber-reinforced polymer (CFRP) composites was investigated experimentally. The grafting of TiO2 and SiC nanomaterials onto the surface of fibers was performed by mixing nanomaterials in the epoxy resin. CFRPs were manufactured using vacuum assisted resin transfer molding (VARTM) in this study and characterized using mechanical and thermal testing. The primary test parameters were carbon fiber with epoxy resin and 0% nanomaterials by weight. An increase in properties was observed in nanocomposite with 2% wt. of nanomaterials when compared with 0, 0.5, and 1% wt. Between 0 wt.% and 2 wt.%, the tensile strength, flexural strength, impact strength, hardness, and HDT properties were increased by 17%, 39%, 32%, 14% and 21%, respectively, due to the addition of nanomaterials into the resin.

Flax–gypsum composites are an emerging class of environmentally friendly materials that combine the mechanical properties of gypsum with the advantageous characteristics of flax fibers. The production of flax–gypsum composites involve the incorporation of flax fibers, derived from the flax plant, into gypsum matrix systems. In order to create a uniform distribution of fibers within the gypsum matrix, the hand lay-up approach has been used to produce the specimens. The fiber content and orientation significantly influence the resulting mechanical and physical properties of the composites. Various tests were conducted on the samples, such as a flexural test, a compression test, a density test, a water absorption test, and a microscopy test. The addition of flax fibers imparts several desirable properties to the gypsum matrix. When combined with gypsum, these fibers enhanced the composite’s mechanical properties, such as flexural strength and compressive strength. The results indicated improved compression and flexural strengths due to effective load transfer within the matrix, for up to 10% of fiber loading. A decrease in composite density upon flax fiber addition results in a lighter material, enabling insights for various applications.