Plastic products, as well as products made from various synthetic materials, are usually made by pouring a liquid synthetic into a mold. The mold will give the liquid shape as it sets into a solid. These molds must be created by a mold builder that can manipulate various materials to create a solid cast for making these products. A mold builder can make molds from a variety of materials, including plastic, resin, metal, and wood. The qualifications for this position can vary, but usually the candidate does not need any specific level of education.
Basic math skills will be necessary, and in some cases an employer may require the mold builder to have working knowledge of various computer programs, such as computer-aided drafting (CAD) programs. These skills can often be learned on the job, though many builders choose to enroll in coursework that will make them more valuable job candidates. A knowledge of various machine tools, mold processes, and materials is also often required, though again, much of this knowledge can be learned while on the job. Many employers will also teach the mold builder the molding process from start to finish so he or she has a broader concept of what is to be done in this type of manufacturing.
Once a mold has been made and materials have been placed within the mold to cure or set, the mold builder may be responsible for removing the materials from the mold. Sometimes this involves breaking the mold, though in other cases the materials can be removed carefully without damaging the mold itself. The mold builder may be responsible for designing the mold in such a way that easy manipulation of the mold and the materials contained therein is possible. This may mean creating hinges or other securing devices, as well as materials such as waxes, resins, or adhesives.
Various chemicals will be used in a mold building setting, so the mold builder may be required to undergo safety training as well as chemical handling training. If the builder is responsible for the use of motorized machinery, it is likely that an employer will require the builder to undergo safety training concerning the use of these machines. Some machines are computer numeric controlled (CNC) which means the builder may be required to undergo training in the use of CNC technology and machinery.