This article discusses technologies focused on processing plastic materials or producing direct tools used in plastics processing. The article focuses on extrusion and injection molding, covering applications, materials and their properties, equipment, processing details, part design guidelines, and special processes. It also covers the functions of the extruder, webline handling, mixing and compounding operations, and process troubleshooting. Thermoforming and mold design are covered. Various other technologies for polymer processing covered in this article are blow molding, rotational molding, compression molding, transfer molding, hand lay-up process, casting, and additive manufacturing.

This article focuses on manufacturing-related failures of injection-molded plastic parts, although the concepts apply to all plastic manufacturing processes It provides detailed examples of failures due to improper material handling, drying, mixing of additives, and molecular packing and orientation. It also presents examples of failures stemming from material degradation improper use of metal inserts, weak weld lines, insufficient curing of thermosets, and inadequate mixing and impregnation in the case of thermoset composites.

Two-component polyurea elastomeric coating/lining systems are the newest technology in the protective coating/lining industry and a wide variety of applications have been developed. These include coating/lining applications over concrete, geotextile membranes, various metals for corrosion and decorative areas, and some plastics. This article discusses the formulation basics of polyurea technology and compares the technology to that of polyurethane and polyurethane/polyurea systems. It addresses performance issues and describes application processing considerations and safety practices of polyurea coating/lining systems.

This article discusses the process details of metal powder injection molding of microcomponents and the powder particle characteristics of feedstock and property requirements of binders. It reviews important characteristics to be considered in the processing steps: venting, channel diameters, binder segregation, binder degradation, feedstock supply, temperature control, demolding, debinding, and sintering. Finally, the article provides information on powder injection molding mold-filling simulation and two-component powder injection molding, offering a method for high-volume production of microcomponents made of multifunctional materials.

Consolidation and shaping of grade powders is carried out using several methods, depending on the size, complexity, shape, and quantity of parts required. This article details the powder consolidation methods of carbide powders: uniaxial pressing, cold isostatic pressing, extrusion, green machining, and injection molding.

Thixomolding is a method of molding thixotropic semisolid magnesium alloy pellets in a machine that resembles an injection molding machine in physical appearance and operation. This article describes the process of thixomolding. The use of hot sprues and hot runners in the thixomolding is discussed. The article provides information on thixoblending and summarizes results from two independent studies of the mechanical properties of recycled AZ91D. It also describes the factors on which the mechanical properties depend and illustrates microstructures of semisolid thixomolded AZ91D.

Molding compounds are plastic materials in varying stages of pellets or granulation that consist of resin, filler, pigments, reinforcement, plasticizers, and other ingredients ready for use in a molding operation. This article describes the material components and physical properties of sheet molding compounds (SMC). The three types of resin paste mixing techniques, such as batch, batch/continuous, and continuous, for an SMC operation are reviewed. The article discusses the design features and functional operations of the two types of SMC machines, namely, continuous-belt and beltless machines. It explains the formulation and processing of bulk molding compounds and reviews molding methods for bulk molding compounds, including compression, transfer, and injection molding. The effects of the fiber type and length and the matrix type on thermoset bulk molding compounds are discussed. It describes the four injection molding processes of injection molding compounds such as feeding, transporting, injecting, and flowing.

Resin transfer molding and structural reaction injection molding belong to a family, sometimes denoted as liquid composite molding. This article provides information on the characteristics and automotive and aerospace applications of liquid composite molding. It reviews techniques that use hard tooling and positive (superatmospheric) pressures to produce structures. The techniques include vacuum-assisted resin injection, vacuum infusion, resin-film infusion, and injection-compression molding. The article provides an overview of the materials that are commonly used together with some of processing characteristics that are important to processing speed and part quality. It concludes with a discussion on design guidelines for the liquid composite molding.

This article describes key processing methods and related design, manufacturing, and application considerations for plastic parts. The methods include injection molding, extrusion, thermoforming, blow molding, rotational molding, compression molding/transfer molding, composites processing, and casting. The article describes principal features incorporated into the design of plastic parts. It concludes with a discussion on the materials selection methodology for plastics.

The goal of design is to improve the overall performance of the metal or ceramic matrix rather than to create a material with different response than the base matrix. This article focuses on the design for manufacturing polymeric composites. Specially developed methods including contact molding, compression-type molding, resin-injection molding, and pultrusion are described. The article also discusses the various factors to be considered in designing for composite manufacturing.

Resin transfer molding (RTM) and structural reaction injection molding (SRIM) are two similar processes that are well suited to the manufacture of large, complex, and high-performance structures. This article discusses the similarities and differences of RTM and SRIM processes and the unique design considerations with respect to the physical properties, geometry, surface quality, process economics, equipment, and tooling of a component that should be considered in choosing RTM or SRIM over other competing processes for fabricating reinforced components.

Injection molding is a process of forcing or injecting a fluid plastic material into a closed mold. The process generally has the advantages of being more readily automated and of permitting finer part details. Injection-molding compounds are thermoplastic or thermosetting materials and their composites that are specifically formulated for the injection-molding process. This article discusses the injection molding process, which includes the two basic categories of thermoplastic and thermoset injection molding, and lists the common thermoplastic and thermoset molding compounds and applications. It also describes the operation of the different types of injection molding machines as well as mold design and process controls. The article also describes the selection of injection-moldable thermosets, and provides an overview of part performance, properties, blowing agents, and aesthetic concerns related to thermoplastic structural-foam injection molding.