Sheet molding compounds (SMCs) refers to both material and process for producing glass-fiber-reinforced polyester resin items. This article discusses the material components incorporated into the resin paste for desirable processing and molding characteristics and optimum physical and mechanical properties, including catalyst, fillers, thickeners, pigments, thermoplastic polymers, flame retardants, and ultraviolet absorbers. It talks about the mixing techniques available for SMC resin pastes, including batch, batch/continuous, and continuous mixing. The article also outlines the design features and the operations of continuous-belt and beltless machine type SMCs.

Thermoforming is a manufacturing process in which thermoplastic sheets are heated, softened, clamped onto a mold, and made to conform to the shape of the mold or forming tool. It is ideally suited to large-volume runs of small items. This article focuses on major phases of thermoforming, namely, sheet transportation, heating, forming/cooling, and trimming, and different thermoforming techniques: basic female forming; basic male forming; matched-mold thermoforming; plug-assist thermoforming; pressure bubble plug-assist vacuum thermoforming; vacuum snapback thermoforming; air-slip thermoforming; and trapped-sheet, contact heat, and pressure thermoforming. It concludes with a discussion on machines and the economic concerns of thermoforming.

Rotational molding is a simple but unique process that has the capability of producing small to large hollow items with very uniform wall thicknesses. Providing an overview of the operating principles of rotational molding, this article discusses the key selection factors, including function and property requirements for resins and additives; size, shape, design, and cost of molded parts; equipment type and size; and the type of mold to be used. Commonly used molds include cast aluminum, fabricated sheet metal, nickel deposit, machined aluminum, silicone, fiberglass, and prototype molds.

This article describes the factors to be considered while performing electroforming process. The factors include the shape and size of the mold, expected durability of the mold, required delivery time, and manufacture and cost of the necessary mandrel. The article discusses mandrel fabrication by either the use of fiberglass/resins or by the machining of the mandrel directly from computer-aided design data. It provides a comparison of nickel and other tooling materials in terms of coefficients of thermal expansion, thermal cycles for compression molding, and thermal cycles for metal autoclave molds.

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.

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.

The selection of the best material for a particular design is intimately associated with the decisions of how to process the material or manufacture a part. This article describes the basic characteristics of manufacturing processes such as material factors, shape factors, and process factors. The influence of materials on the manufacturing cost is described with a specific example. The article discusses the design for manufacturability to minimize the total number of parts, use readily processed materials, and eliminate machining and finishing operations. It reviews the factors influencing the selection of a material for production, including material composition, heat-treated condition, surface finish, and cost of material. The article describes the material characteristics, such as terms formability, workability, castability, machinability, and weldability, that aid or hinder the production of a part without defects.

Manufacturing process selection is a critical step in plastic product design. The article provides an overview of the functional requirements that a part must fulfil before process selection is attempted. A brief discussion on the effects of individual thermoplastic and thermosetting processes on plastic parts and the material properties is presented. The article presents process effects on molecular orientation. It also illustrates the thinking that goes into the selection of processes for size, shape, and design factors. Finally, the article describes how various processes handle reinforcement.

Rapid prototyping (RP) is a field in manufacturing involving techniques/devices that produce prototype parts directly from computer-aided design models in a fraction of time. This article discusses the principles of RP and three major commercial processes, based on their layer creation method. These include selective cure layered processes, extrusion/droplet deposition processes, and sheet form fabricators. The article provides information on the three classes of RP, namely, voxel sequential volume addition, periphery cutting, and area sequential volume addition. It presents equations that represent build times for each of the three classes.

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.

This article explores the possibilities and limitations imposed by manufacturing processes and materials. Detailed design rules for the processes are presented. The article lists the main features of process groups in a tabular form. The physical characteristics and ratings of relative cost and production factors are also tabulated. The process groups include casting; deformation; powder processing; machining; noncutting; joining; ceramic, glass, and polymer processing; and composites manufacturing.

The horsepower requirements to cut various metal alloys provide an indication of the relative ease and cost of machining, but several other important factors include cutting tool material, chip formation, cutting fluids, cutting tool wear, surface roughness, and surface integrity. This article reviews these general machining factors as well as specific cutting tool and cutting parameters for the six basic chip-forming processes of turning, shaping, milling, drilling, sawing, and broaching. Best practices for each of the six chip-forming processes are suggested for optimized machining of aluminum alloys. The article lists the inherent disadvantages of machining processes that involve compression/shear chip formation. It discusses the machining of aluminum metal-matrix composites and nontraditional machining of aluminum, such as abrasive jet, waterjet, electrodischarge, plasma arc, electrochemical, and chemical machining.