A practical safety routine for plastic moulding and extrusion units: who checks what, and when

The safety gate on press nine has a cracked limit switch, so someone has wedged it with a lump of sprue to keep the press cycling. Everyone on the shift knows. Nobody has written it down. It will stay that way until a hand is between the platens when they close.

Plastics floors carry a particular mix of hazards. Heat sits at the nozzle, barrel, hot runner manifold and die head. Platens, toggles and clamps move with great force. Robots, sprue pickers and granulator blades sit close to busy hands. Extrusion adds haul-off nips, saws and winders, and converters add slitter knives. Heavy moulds swing on cranes, while hydraulic oil and spilled pellets make the floor treacherous. A routine that works gives each role its own short check, a fixed moment to do it, and steps that take minutes.

• Operator, every shift start. The safety gate halts the machine when opened and the emergency stop works. Guards and the nozzle shroud are fitted, pellets and oil are swept away, and gloves and ear plugs are on.
• Setter, at every mould change. Lifting gear, shackles and eyebolts are inspected and the eyebolt is fully threaded. Clamps are tight, water and hydraulic hoses are dry, and a visor is worn for purging.
• Line leader, before each extrusion start-up. Die head covers, haul-off and saw guards, the winder nip guard and the vacuum tank lid are in place. Heat-resistant gloves are ready for threading.
• Shift lead, mid-shift walk. Watch for gates propped open, hands inside the mould area, missing guards, oily floors and skipped breaks. In summer, check that drinking water is within reach.
• Maintenance, weekly. Test interlocks and light curtains. Inspect hydraulic hoses, granulator blades and the lid interlock, crane chains and slings, and panels near heater wiring.
• Safety officer and plant head, monthly. Review near misses, injuries and repeat faults. Walk the floor alongside an operator, not just a supervisor.

Machine number, date, shift, operator name.
Safety gate opened: machine stopped? Yes or no.
Emergency stop pressed and reset: worked? Yes or no.
Guards, nozzle shroud or die head cover in place? Yes or no.
Robot cell or conveyor fence closed and interlocked? Yes or no.
Floor clear of pellets, regrind and oil within a metre of the machine? Yes or no.
Hoses and couplings: any visible leak? Yes or no.
Gloves, ear plugs and safety shoes on? Yes or no.
Any 'no' means the machine does not start until the shift lead has seen it. Signature of operator and lead.

Hang the card on the machine and collect it when the shift closes. The rule on the last line matters most. A check that cannot halt the machine is only paperwork.

• Granulators. Never reach into the feed throat. The lid interlock is tested weekly, and blades are changed only after the isolator is switched off and padlocked.
• Purging. Molten purge can spatter. Wear a visor and heat-resistant gloves, and keep everyone else clear of the nozzle. Some resins give off irritating fumes when degraded, so ventilation matters.
• Mould handling. Only trained people sling and lift moulds. Nobody walks under a suspended tool.
• Heat. Hot surfaces are marked. Burn gel and cold running water sit near every press bay.
• Manual handling. Resin bags, drums and finished rolls are lifted with a method taught on day one, using trolleys or hoists where available.

Many plastics injuries happen late in a long shift. A tired operator reaches past a gate to grab a short shot. A drowsy winder hand puts a glove near the nip. In summer the bay beside the extruder barrels gets fierce, and dehydration slows reactions. Plan rest breaks and water rounds into the night roster, keep the lead's walk going after midnight, and rotate the hottest stations.

1. 1

   Walk the floor with two operators

   List the real hazards at each machine type, in the plant's own words. Include the ones everyone has learned to live with, like the wedged gate on press nine.

2. 2

   Write the role checks

   One short list per role, as above. Each check should take minutes, not half an hour.

3. 3

   Give the stop authority in writing

   An operator may refuse to start a machine that fails its card, and the lead must look before it runs.

4. 4

   Teach it at the machine

   Each role is shown their check on their own machine, not in a classroom. New joiners get it on day one.

5. 5

   Open a blame-free near-miss route

   A simple slip or a word to a named person, kept well apart from warnings and discipline. An incident slip template is a good place to begin.

6. 6

   Review monthly and act visibly

   Pick the top two repeat items and fix them. Announce the repair at the next shift huddle.

Expect the first month to feel slower. Cards come back half-filled, and a lead or two grumbles about the walk. Keep going. By the second month the checks become habit, and the floor starts reporting things it used to step around, from a frayed sling to a loose heater band cover.

Our safety and wellbeing work can build a routine like this with your leads and setters. Press shops can read the press shop safety notes. Drum and can lines have a page on heat and handling at blow moulders. Converters with print and slitting lines can see knife and hygiene safety for packaging converters. For why routines beat wall charts, read this short argument. The wider sector view is on our plastics people overview.