01Ball, wiper and brush cap placing
A complete nail polish machine drops a mixing ball, presses a wiper plug into the neck, then places and tightens a cap with the brush on its stem. Ask which stations the price includes; each missing one is another operator.
02Keeping pigment in suspension
Pigment settles in a still hopper, so first and last bottles can differ in shade. Ask whether the hopper is stirred, including while the line waits.
03Dosing a lacquer that thins when stirred
Polish thins while it moves and thickens at rest. Piston, peristaltic and rotor pumps all sell under this name. Ask for nozzle cut-off and fill profile on your lacquer, including after a pause.
04Seals and tubes against solvent
Acetate solvents swell some rubbers and tubes, and a swollen seal changes the dose. Ask for the material of every seal, tube and O-ring in the product path.
05Vapour near motors and switches
Ask whether motors, sensors and controls near the heads are offered as ATEX equipment under 2014/34/EU. Whether your room is a hazardous zone is your own assessment.