PrazamanaLoading
A robotic doffing and wrapping cell had multiple ways for personnel to be exposed to robot motion, a rotating wrap shaft, and unauthorized access — including a light curtain that didn't stop the machine when interrupted. Here's what we found — and the solution we engineered.
The cell pairs a robot handling doff pick-and-place at two trolley entry points — 1A and 1B — with a rotating-arm wrapping station. A pre-project hazard review walked the cell end to end and found six distinct ways a person could be exposed to hazardous motion, from simple unauthorized entry to a light curtain that failed to stop the machine when it was interrupted. Every modification below was implemented specifically against one or more of these findings.
Hazards Identified6
Safety Systems Integrated5
A pre-project hazard review of the cell found 6 distinct ways personnel could be exposed to hazardous motion.
In short, the cell exposed personnel to
Robot Arm Movement
Unexpected or uncontrolled movement of the robot arm can cause serious impact or crushing injuries to personnel entering the hazardous area.
Light Curtain Hazard
Incorrect positioning or insufficient height of the light curtain may allow personnel to crawl underneath or bypass the detection zone.
Access During Automatic Operation
Unauthorized or uncontrolled access to the robotic cell during automatic operation can expose personnel to multiple mechanical and crushing hazards.
All 6 hazards, in detail
A person could enter the robotic cell along with or behind the trolley while the robot was operating, creating a risk of serious injury.
A similar access hazard was identified on Side 2, where a person could enter the robot operating area during trolley movement.
During maintenance or doff removal, a person could remain inside the cell while another operator closes the door, resets the safety system, and starts Auto mode — risking unexpected robot movement and a serious or fatal accident.
During the doff pick-and-place operation, personnel could be exposed to robot movement and the rotating shaft, creating a collision or crushing hazard.
During the wrapping process, the rotating shaft with the wrapping roll could come into contact with the operator's face or head, creating a serious struck-by or entanglement hazard.
The light curtain was installed for operator protection; however, the machine did not stop when the light curtain was interrupted — a critical safety-function failure.
Overall, the identified robotic-cell hazards were addressed through light curtains, radar sensors, fencing, Safety PLC logic, VFD STO, muting logic, reset logic, and restart prevention.
Tell us about your cell or line and we'll walk it the same way — hazard by hazard.
