Alternatives to Injection Molding

While injection molding is the most versatile of all plastics fabrication processes, it is not suited for very large parts. This chapter discusses several alternative processes to injection molding, namely, extrusion, blow molding, rotational molding, thermoforming, expanded bead foam molding and extruded foam molding, and 3D printing. With the growing use of plastics, each of these technologies has sophisticated computer-controlled machines that, in conjunction with innovative tooling, are used to efficiently make multimaterial parts that can be decorated during the part forming process. The evolution of these technologies have made possible an unending number of everyday use items such as water bottles, food packaging, ketchup bottles with multifunctional lids, containers with handles, sophisticated toys, baby strollers, canoes and kayaks, many automotive components, and a host of medical devices.