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Miniaturization of Complex Ceramics
Published in Debasish Sarkar, Ceramic Processing, 2019
Prior to highlighting injection molding, a brief discussion on the origin and different types of molding protocol will provide a better insight on the subject. Molding is a processing technique to manufacture a rigid-shaped component or structure using liquid, pliable, or solid material. A mold is a hollow cavity that consists of two halves depending on the complexity of the output. During molding, the flowable mass hardens after cooling and adopts the required shape followed by release through dissembling the movable mold parts. This method is cost-effective, consumes less time, and enables complex geometries to be drawn. Rapid and accurate geometry in the manufacturing of household to aircraft components are the major advantages of this process. Conventionally, different classes of molding processes are available, such as injection molding, extrusion molding, blow molding, matrix molding, compressive molding, spin-casting, centrifuge casting, transfer molding, powder metallurgy, and sintering. Among these, injection molding is an effective process to fabricate a wide range of components imparting flexibility in materials such as polymers, metals, ceramics, and their composites as well. The machine is primarily divided into three units, namely, an injection unit, a mold, and a clamping unit, as illustrated in Figure 9.9.
Thermally enhanced polyolefin composites: fundamentals, progress, challenges, and prospects
Published in Science and Technology of Advanced Materials, 2020
A.U. Chaudhry, Abdel Nasser Mabrouk, Ahmed Abdala
Furthermore, the filler size greatly influences κc as small size fillers result in larger interfacial area and more pronounced phonon scattering. In contrast, large fillers are more effective in creating a percolated network, which reduces the thermal interfacial resistance. Nonetheless, some reports claim κc is independent of the particle size as nano-size fillers resulted in similar κc enhancement as microsize fillers [58]. Also, the dependence of κc on network formation by conductive fillers is well established regardless of the filler size and thermal resistance between the filler and the matrix [39,58–60]. Furthermore, κc can also be improved by other techniques such as using hybrid fillers with different sizes, shapes, and types as well as surface treatment of the filler [61–63]. Moreover, the composite microstructure that develops during processing as dictated by the processing conditions and the ability/tendency of the filler to orientate, agglomerate, and form network also affects κc. During processing, the filler particles can be oriented using externally applied fields and shear or extensional flow. Similarly, the formation of a filler network can be achieved by self-assembly of the filler particles in the polymer matrix, molding of the mixture of the filler and polymer powders, in situ polymerization or double percolation. Agglomeration of the filler is sometimes necessary to achieve high and isotropic κc [64–70]. Filler dispersion in the host matrix is significantly impacted by the processing method. κc for composites with the same filler loading can vary considerably based on the processing method following the order [71,72]:
The effect of molding process on thermomechanical properties of feather nonwoven reinforced polyester composites
Published in The Journal of The Textile Institute, 2022
Ouahiba Mrajji, Mohamed El Wazna, Abdeslam El Bouari, Omar Cherkaoui
The mechanical properties of the natural fiber-reinforced composites depend on the fiber, matrix, molding process and interphase fiber-matrix. Figure 11 shows the values of young's modulus of feathers nonwoven reinforced polyester composite manufactured by RTM, infusion molding and vacuum molding.