moulders

A moulder, or molder in American English, is a skilled worker who creates moulds used for casting processes in industries such as metal foundries, plastics, and ceramics. In metal casting, moulders prepare the mould cavities from patterns and moulding materials, assemble cope and drag sections, and often place cores to form internal features. They aim to produce moulds that are dimensionally accurate and free of defects.

Typical duties include reading blueprints or pattern drawings, selecting appropriate moulding materials (such as green sand, dry sand, loam, or shell processes), and packing or ramming the mould to form the cavity. Moulders set up gating systems, vents, and risers, check alignment, and ensure proper surface finish. After moulds are used to pour molten metal, they perform shake-out, fettling, and cleaning of the casting, and may perform basic inspection of the mould or casting for defects.

The process generally involves pattern fabrication coordination, core setting for internal features, mould assembly, drying or curing as required by the material, and finally removing the finished casting from the mould. Moulders often work closely with patternmakers, foundry workers, and inspectors to ensure tolerances and quality standards are met.

Training and safety are important, with many moulders qualified through apprenticeships or on-the-job training. Skills include blue-print literacy, dimensional measurement, knowledge of mould materials and metals, and strict attention to safety due to exposure to hot metals, dust, and heavy equipment.

Regional terminology varies: “moulder” is common in the UK and Commonwealth, while “molder” is used in the United States. Related occupations include patternmaker and core maker.