An employee of a pyrotechnic company was in the process of using a 140-tonne hydraulic press to produce pyrotechnic blocks by compression. After having extracted the compressed blocks, she positioned antistatic film on the lower compression die for the following cycle and initiated the die’s descent. As she was weighing the composition for the next compression, she heard a crackling sound and saw a small flame appear at the base of the die via the monitor.

The employee actuated the emergency stop, exited the workstation and raised the alarm by telephone. The event was over when the in-house fire-fighters arrived at the scene.

An examination of the press revealed that dry residues below the die had been ignited under the crushing force. Only a few grams had been burnt. The residues had accumulated due to the difficulty in accessing the rear part of the press for cleaning purposes: access to the rear part was prohibited by safety sensors and by the absence of means to clean those hard-to-reach areas.

The operator modified the PLC program to allow the operator to access the rear part of the tool for cleaning purposes at the end of the day. An appropriate tool was made available to access the hard-to-reach areas.