Don’t In Front of A Die When An Extruder is Starting Up

Don't in Front of a Die when an Extruder Is Starting up

Air in the extruder and possibly gas from degraded products (if the extruder has been present at temperature with material in the barrel for some time) is forced out of the extruder on start-up. If some polymer is left in the barrel, trapped air can be compressed, blowing the hot polymer out of the die, or blowing the die off the end of the extruder. Standing in front of the extruder creates an excellent opportunity for molten polymer to be blown out of the die, causing burns. If the die is blown from the extruder by the pressure, one can be seriously injured or killed by the impact of the die or broken bolts or from the die falling on the skin.

The potential for electrical shock exists when removing the extruder covers, thus exposing bare wires and electrical connections. Extruder heater bands are normally 220–440 V and can cause serious electrical shock. Check the wires to the heater bands on the die and adapters to assure that there are no frayed, bare, or exposed wires, or connections that can cause electrical shock. In some extrusion processes, water-cooling baths are very close to the die, which can create additional electrical hazard. Operators unless properly trained should never remove guards exposing electrical terminals on heaters or open electrical cabinets to solve electrical problems.

The third major potential safety hazard around extruders is falls. Pellets spilled on the floor are slippery and need to be cleaned up immediately. At start-up the extruder normally generates some scrap, which may be on the floor around the die of the extruder. This creates tripping hazards that must be removed immediately. Occasionally, processing issues arise at start-up leading to a large quantity of material on the floor around the extruder. In these situations, the extruder should be shut down, the area must be cleaned, and then the extruder should be restarted. Some extrusion processes use water for cooling. Water spills on the floor should be removed with a wet dry vacuum and/or swept to a drain. Wet floors are very slippery and can cause falls.