A professional who fills spinnerette packs (metal cups) with measured amount of treated sand to filter impurities from molten nylon before extrusion into filaments. Respnsibilities include:

• Examines holes in bottom of pack, using microscope, to detect damaged or clogged openings.
• Weighs out prescribed amounts and grades of treated sand and pours sand into pack, leveling sand with crescent-shaped tool.
• Repeats filling and leveling process until specified number of layers have been built up, according to type of nylon to be spun.
• Disassembles used packs, pours out sand, and washes pack in soapy water to remove burned sand adhering to cup after extrusion of molten nylon.