Ribbon coder and printing station

Ribbon coder: threading and alignment

Most coding faults on this line come from a ribbon that is not straight, not at the right tension or not covering the full code. Follow this procedure at every ribbon change and whenever print is incomplete.

1. 1Isolate the printer and let the print head cool.
2. 2Remove the used core and fit a new ribbon of the correct width and grade. Seat the supply roll and take-up core fully on their spindles.
3. 3Check the ink side: the coated (ink) side must face the label or bottle. Scratch each side lightly; the side that marks is the ink side.
4. 4Thread the ribbon along the marked path around every guide roller. Do not shortcut a roller or twist the ribbon.
5. 5Centre the ribbon over the print area so it overlaps the code by at least 2–3 mm on each side.
6. 6Use the guide adjuster to make the ribbon run straight and square to the rollers. Lock the adjuster.
7. 7Take up slack by turning the take-up core until the ribbon is flat and taut, with no wrinkles.
8. 8Check the print head is parallel to the label surface and pressure is even across its width.
9. 9Set the advance length to the code length plus 1–2 mm.
10. 10Print 5–10 test codes: every character complete, sharp and in position.
11. 11Run for 5–10 minutes and check again. A crooked ribbon walks sideways and causes half print after a few minutes.
12. 12Record the ribbon change and test print in the BPR.

Printing station: side-grip conveyor and printer alignment

At the print station two red side-grip belts carry the bottle past the ribbon coder, which prints near the bottom of the bottle. Each belt has its own motor; both are switched on and off and speed-set from the PLC/HMI. The belts, printer head and ribbon must be set together.

1. 1Place a bottle between the side-grip belts.
2. 2Use the width adjusting knobs to set the belt gap: the bottle is held firmly and upright, does not slip when pushed lightly, and is not squeezed or dented.
3. 3Too tight: bottles are damaged or do not move through properly (P-12). Too loose: bottles fall to the floor because the print station is open underneath (P-13).
4. 4Check the belts are parallel and running centred on their rollers.
5. 5Set both belt motors to the same speed on the PLC/HMI so the bottle does not twist (P-15). Match the side-belt speed to the conveyor feeding the station.
6. 6Set the printer head height to the print area near the bottom of the bottle.
7. 7