Changeovers eat the day: HR for label manufacturers

A label unit takes an order for a few thousand pharmacy labels in three colours, then a shampoo back label with cold foil, then a run of barcode stickers on thermal paper. On a narrow web press each change means new photopolymer plates, a different anilox roll, fresh UV inks, another rotary die and a new reel of face stock. The press may run each job for less time than it takes to change over to it.

Hence the label manufacturers page leads with changeovers. An operator who changes over slowly or carelessly adds hours to the day. A fast one saves them. Usually nobody has recorded why.

• Mounts plates offline. Plates for the coming job go onto sleeves or cylinders with stickyback tape at the mounting table as the press keeps printing.
• Draws inks down early. The next shades are mixed, drawn down on the job's face stock and checked before the stop, not after.
• Checks the die. The flexible die is pulled from the die store, checked for nicks and the right label gap, and laid beside the magnetic cylinder.
• Stages the material. Face stock, liner type and cores of the right size are at the unwind, with the job ticket read.
• Splits the stop. Operator on print stations and register; assistant on die station, matrix stripping and rewind. Nobody waits for the other.
• Gets a sellable roll fast. Register and colour brought in on the first metres, with first-off approval signed and the matrix running clean.

Changeover time is rarely written down. The job card shows start and finish, but not how long the press stood still between jobs or why. The owner sees that the day shift finishes more jobs and decides the night operator is slow. The truth may be that the day assistant was taught to mount plates and the night assistant never was. Or the planner may give nights the awkward jobs with foil and lamination. Without a record, the argument is about people.

• Adding or swapping foil. Cold foil needs an adhesive plate and a foil web threaded through the nip; hot foil needs a heated die and dwell settings.
• Paper face stock to film. Moving from vellum or chromo paper to PP or PE film changes ink adhesion, UV lamp power and web tension.
• A new repeat length. A different label pitch can mean another magnetic cylinder size and a gear change, not just a fresh die.
• Liner changes. Glassine to PET liner, or a thinner calliper, alters how the matrix strips and how the turret rewinder behaves.
• Booklet or peel-and-read labels. Extra layers, lamination and registration between webs turn one changeover into several.
• Winding direction and cores. Customers specify unwind position and core size, and a wrong one means a full rewind at the inspection table.

1. 1

   Time three changeovers per operator

   From last good label of one job to first approved label of the next. Note who ran it, what changed and what caused any wait.

2. 2

   Watch the best pair

   List what they do before the stop, during it and after. Pay attention to the assistant as much as the operator.

3. 3

   Write the sequence with them

   One page, in their words, split into before the stop, the stop itself and getting to first-off. Ask the other operators to test and improve it.

4. 4

   Split the work between operator and assistant

   Make each person's tasks during the stop explicit, so they work in parallel. Teach the assistant their half properly.

5. 5

   Give the planner the facts

   Sequence jobs to share anilox rolls, dies or colours where possible, and spread the hardest changes across shifts fairly.

6. 6

   Re-time a month later

   Compare with the first timings. Recognise the pairs who improved, and look again at any changeover that still runs long.

In many label units the press assistant learns by watching, and progress depends on whether the operator bothers to explain. Give the assistant a list of changeover tasks to learn in order: rewind and core change, matrix stripping, die station, plate mounting, ink drawdown, then register. Check the list monthly with the operator. Building that route, so the next printer exists before you need him, is covered on the skills route page for label presses.

If pay and grade ignore changeover skill, there is little reason to teach it. Grade operators partly on changeovers completed to the standard, and assistants on the tasks they can do alone in the stop. A skills chart of who can run which press, and who backs up each colour reference, keeps a small crew from depending on one pair. The competency and talent page for label units covers that chart.

Date, shift, press, operator, assistant.
Job from and job to, with what changed: plates, anilox, inks, die, face stock, foil.
Time of last good label and time of first approved label.
Pre-staged before the stop? Plates, inks, die, material: yes or no for each.
Cause of any wait: missing plate, wrong die, ink not ready, artwork query.
First-off signed by, and anything to fix in the standard.

If the best operator and assistant always work days, nights will always look slow. Rotate pairs on a published rota, and put at least one changeover-trained assistant on every shift. Limit long spells at the inspection rewinder as well, because tired checkers miss defects. For drawing up those rotations, see rotas and leave in label units.

Time three recent changeovers on each press and note who ran them and what caused any wait. That one exercise usually shows where the hours go. Changeovers reward practice covers the same habit across packaging plants. For how label units fit beside box, film and moulding plants, see the packaging group page. To have a changeover standard and assistant route set up with your operators, send us a note of your needs.