How do I cover for a process technician who is absent?

Short answer: in layers. Tonight you need someone who can keep a running mould steady. This month you need a named understudy for each press group. Within a quarter you need setting sheets good enough that the understudy can start a mould without phoning anyone.

Most plastics units have one or two people who change moulds, chase defects and approve the first good parts. When one of them is sick, on leave or travelling home, the presses keep cycling for a while. Then something drifts, and the floor discovers how much rested on a single pair of hands.

• Mould changes wait. Crane, eyebolts, locating ring, clamps and water hoses are routine for the technician and strange ground for everyone else.
• Defects go unanswered. Sink marks, short shots, silver streaks and weld lines each need a different correction, and operators usually have permission for none of them.
• First-off approval stalls. Somebody has to hold the first parts against the limit sample and sign before the lot runs.
• Colour and grade changes turn risky. Purging the barrel, checking dryer hours and resetting the heater zones are skipped or guessed.
• The phone starts ringing. Supervisors call the technician at home, and a day off stops being one.

1. 1

   Layer one: a senior operator who may hold a running mould

   On every shift, name one operator allowed to adjust a short list of values inside a written band, such as cooling time and hold pressure. Anything outside the band stops the press.

2. 2

   Layer two: an understudy for each press group

   Group presses by tonnage or by mould family. For each group, pick a second person who has watched several changes and done one under supervision. Record it on the skill matrix.

3. 3

   Layer three: a setting sheet for each mould

   Written by the technician, tested by the understudy on a day shift, kept in a sleeve at the press. It lets a capable person start the mould without guesswork.

4. 4

   Layer four: a call list with limits

   Who to ring, in which order, for which faults and between which hours. Agree it with the technicians so a call at home is an exception they accepted, not a habit.

• May adjust, inside the band: cooling time, hold time, a small step on the nozzle zone, cycle delay.
• May not touch: the velocity profile, switchover position, decompression and suck-back, clamp force, hot-runner set-points or the thermolator set-point.
• Must stop the press for: a sticking ejector pin, a weeping hydraulic seal, a water leak at a quick-coupling, dieseling burns, or any defect the sheet does not name.
• Must log every move: value before, value after, time, initials. The technician reads the log next morning.

Take the press list and mark, for each shift, who can start each mould alone. Then mark who can only keep it running. The gaps usually show within an hour. A hot-runner tool only one person will touch. A glass-filled nylon job that only the day technician runs. A night crew where nobody may go past the cycle timer.

Next, look back over the last month. Which presses waited, on which shift, and for whom? If one name sits behind most of the waiting, that person is the weak link. The skill matrix template in this series gives a layout for recording it.

Mould number, part name, customer and cavities in use.
Press group and the tonnage range it runs on.
Resin grade, dryer temperature and hours in the dryer before use.
Heater zones from feed throat to nozzle, plasticising speed and backpressure, with the band an operator may adjust.
Velocity profile, injection pressure, switchover position, decompression and suck-back.
Hold pressure, hold time and the cushion to watch.
Cooling time and the water circuit, in and out, with hose colours.
Usual defects on this tool, from sink to dieseling, and which knob to turn first.
Author, tester, and the latest revision date.

Yes, once the skill is proven. Tie the step to a sign-off: can start a named mould group alone, witnessed by the technician and the production head. Paying for a title without the sign-off teaches everyone that the ladder rewards time served. A grade scale checked against nearby moulders, as described on the injection moulding pay page, keeps the step from becoming a private favour.

Usually it is not refusal. It is worry that a written sheet makes them replaceable, plus no spare minute on a busy shift. Answer both. Say plainly that the sheets protect their weekly off and their leave. Give them paid hours away from the press to write, and put their name on every sheet. If knowledge still stays locked away after that, hold a private conversation early, before resentment sets on either side.

Inside a band, yes. The danger is not an operator touching a value. It is the operator changing it quietly and the next crew never knowing. Print the band on the sheet, log every change on the shift log, and let the technician read that log each morning. The plastics hub page explains how this fits with handover between shifts.

Set readiness by sign-offs, not by the calendar. A sensible order runs like this. Watch several changes. Do two with the technician alongside. Do one alone on a day shift with the technician on site. Only then join the night roster. Practice decides the pace. If the technician always does the change because it is quicker, the understudy never moves.

Mark the press list by shift. Circle the presses only one person can start. Pick one understudy for the worst group and ask the technician for the first three setting sheets. For help designing the grade scale or the cover rules, tell us about the unit through the requirements form.