Plastic gears are continuing to displace metal gears in applications ranging from automotive components to office automation equipment. This chapter discusses the characteristics, classification, advantages, and disadvantages of plastics for gear applications. It provides a comparison between the properties of metals and plastics for designing gears. The chapter reviews some of the commonly used plastic materials for gear applications including thermoplastic and thermoset gear materials. The chapter also describes the processes involved in plastic gear manufacturing.

This chapter discusses the effect of fiber length and orientation on the strength and stiffness of discontinuous-fiber composites. It also describes several fabrication processes, including spray-up, compression molding, reaction injection molding, and injection molding.

This article describes key processing methods and related design, manufacturing, and application considerations for plastic parts and includes a discussion on materials and process selection methodology for plastics. The discussion covers the primary plastic processing methods and how each process influences part design and the properties of the plastic part. It also includes a brief description of functional requirements in process selection; an overview of various process effects and how they affect the functions and properties of the part; and the selection of processes for size, shape, and design detail factors.

This article is a compilation of abbreviations and symbols related to characterization and failure analysis of plastics.

This chapter includes a comprehensive set of definitions used in powder-binder processing.

This chapter describes the molecular structures and chemical reactions associated with the production of thermoset and thermoplastic components. It compares and contrasts the mechanical properties of engineering plastics with those of metals, and explains how fillers and reinforcements affect impact and tensile strength, shrinkage, thermal expansion, and thermal conductivity. It examines the relationship between tensile modulus and temperature, provides thermal property data for selected plastics, and discusses the effect of chemical exposure, operating temperature, and residual stress. The chapter also includes a section on the uses of thermoplastic and thermosetting resins and provides information on fabrication processes and fastening and joining methods.

To ensure the proper application of plastics, one must keep in mind three factors that determine the appropriate end-use: material selection, processing, and design. This article begins by providing information on various factors pertinent to the anticipated use conditions of the article to be designed. This is followed by a discussion on several stages necessary to define the geometry of plastic parts. Details on the strength of and cost estimation for plastic parts are then provided. The article ends with a section providing information on the structure, properties, processing, and end-use applications of plastics.

This chapter is intended to identify materials, processes, and designs that will lead to great advances in powder-binder forming technologies. It discusses some of the structures obtained through these advances in powder-binder technologies such as binder jetting and extrusion-based additive manufacturing, including bound-metal deposition and fused-filament fabrication: oxidation-resistant high-temperature alloys, anisotropic structures, submicrometer-scale structures, surface hard materials, and artist metallic clays. Some of the advances discussed include the developments in process involving plastics, emulsions, ceramics, and porous structures and foams. Improvements in the design processes have led to the development of functional structures, controlled porosity, and bioinspired structures.

This introductory article describes the various aspects of chemical structure and composition that are important to an understanding of polymer properties and their eventual effect on the end-use performance of engineering plastics, namely thermoplastics and thermosets. The most important properties of polymers and the most significant influences of structure on those properties are covered. The article also includes some general information on the classification and naming of polymers and plastics.

This article discusses electrical testing and recommended procedures for determining the electrical properties of insulating materials, with particular emphasis on plastics. It describes the electrical characteristics of various forms of plastics and also presents definitions of the terms used in connection with testing and specifying plastics for electrical applications.

Elastomers comprise a subclass of polymers that display the ability to stretch and recover that is typical of a rubber band. This chapter describes the properties determined by tensile testing of elastomers and the factors influencing them, namely, structuring of the molecular matrix, compounding, specimen preparation, specimen type, vulcanization parameters, and temperature. The chapter also provides information on ASTM D 412, the most widely referenced standard for determining the tensile properties of elastomers.

This chapter provides details on powder-binder processing for three materials, namely precipitation-hardened 17-4 PH stainless steel, cemented carbides, and alumina. The types of powders, binders, feedstock, shaping processes, debinding, sintering cycles, compositions, microstructure, distortion, postsintering treatments, and mechanical properties are presented for each. The shaping options include powder-binder approaches such as binder jetting, injection molding, extrusion, slip and slurry casting, centrifugal casting, tape casting, and additive manufacturing. Sintering options are outlined with respect to attaining high final properties.

This chapter familiarizes readers with the many and varied thermoset composite fabrication processes and the types of applications for which they were developed. It describes wet lay-up, prepreg lay-up, and low-temperature vacuum bag curing prepreg processes, which are best suited for low-volume, medium-sized and larger parts. It also discusses filament winding and preforming processes (including weaving, knitting, stitching, and braiding) in addition to resin-transfer molding, resin film infusion, and pultrusion.

This article reviews various analytical techniques most commonly used in plastic component failure analysis. The description of the techniques is intended to make the reader familiar with the general principles and benefits of the methodologies. The descriptions of the analytical techniques are supplemented by a series of case studies that include pertinent visual examination results and the corresponding images that aided in the characterization of the failures. The techniques covered include Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, thermomechanical analysis, and dynamic mechanical analysis. The article also discusses various analytical methods used to characterize the molecular weight distribution of a polymeric material. It provides information on a wide range of mechanical tests that are available to evaluate plastics and polymers, covering the various considerations in the selection and use of test methods.

This article describes in more detail the fundamental building-block level, atomic, then expands to a discussion of molecular considerations, intermolecular structures, and finally supermolecular issues. An explanation of important thermal, mechanical, and physical properties of engineering plastics and commodity plastics follows, and the final section briefly outlines the most common plastics manufacturing processes.

Polymer-matrix composites are among the lightest structural materials in use today. They are also highly resistant to corrosion and fatigue and their load-carrying capabilities, such as strength and stiffness, can be tailored for specific applications. This chapter discusses the primary advantages and disadvantages of polymer-matrix composites, how they are produced, and how they perform in different applications. It describes the construction of laminates, the fibers and resins used, and the methods by which they are combined. It explains how strength, modulus, toughness, and high-temperature and corrosion behaviors are determined by the orientation, shape, and spacing of fibers, the number of plies, resin properties, and consolidation and forming methods. The chapter also covers secondary fabrication processes, such as thermoforming, machining, and joining, as well as production equipment and product forms, and include guidelines for optimizing tradeoffs when selecting fibers, resins, and production techniques.

This chapter is a detailed account of various attributes related to mixing and testing of powder-binder feedstocks. Mixing parameters and their effects on feedstock properties is discussed. The attributes reviewed include mixture homogeneity, wetting, powder-binder ratio, feedstock density, elastic modulus, rheological behavior, particle size, formulation control, feedstock mixing, and feedstock properties. The chapter also provides information on the processes involved in feedstock preparation and testing.

This chapter recounts some of the early efforts and milestones in the development of stainless steel powders and their use in powder metallurgy applications.