Adjust calender rollers for production line change; Weigh resins, colorants and other chemicals according to formulae; Unload mixture into container or conveyor for further processing; Place weighed materials in mixing machines; Operate mixing machine to blend plastic and other chemicals to a specific consistency and viscosity; Follow formulation card to mix resin batches for injection moulding process; Change dies on extruding machines according to production line change; Trimming and sanding plastic or fiberglass parts; Prepare and change moulds and adjust equipment for production line change; Set up and operate one or more moulding machines to mould plastic products; Set up and operate calender machines to transform plastic bales or slabs into continuous sheets or films of specified thickness; Set up and operate extruding machines to extrude plastic compound through a nozzle or die