A strip end proximity sensor is a non-contact sensing device used in roll forming machines to detect when the end of a metal strip or coil approaches the feed system.
It ensures:
Coil end detection
Controlled feed stop
Prevention of sudden strip loss
Reduced mechanical shock
Operator warning alerts
This sensor protects feed systems and downstream forming stations from abrupt material loss.
Strip end proximity sensors are typically installed:
Near the entry section after the uncoiler
Before the pinch roll assembly
Along the strip support roller area
Mounted on adjustable brackets near strip path
Positioned to detect trailing strip edge
Proper positioning ensures reliable detection before strip disengages from drive rollers.
Senses absence of metal strip.
Sends signal to PLC to halt feed drive.
Alerts operator of coil completion.
Avoids sudden loss of strip tension.
Sensor monitors strip presence
Metal strip passes within sensing range
Sensor outputs signal while metal is present
When strip end passes, signal changes
PLC triggers stop sequence or warning
Detection typically occurs milliseconds before strip disengagement.
Most common — detects metal presence.
Uses light beam interruption.
Detects material change (less common for metal).
Inductive sensors are preferred for metal strip detection.
Strip end proximity sensors typically connect to:
PLC digital input
Safety relay (in certain designs)
Alarm indicator
HMI display
Output types include:
PNP
NPN
Normally Open (NO)
Normally Closed (NC)
In high-speed roll forming lines:
Reaction time must be fast
Sensor range must be consistent
Signal filtering may be required
Mount rigidity prevents vibration-triggered faults
Delayed detection may cause feed shock.
Thicker materials:
Provide stronger inductive signal
Easier detection
Require stable bracket mounting
High vibration environments demand robust sensors.
Thin materials:
May reduce detection distance
Require precise sensor positioning
Benefit from adjustable sensitivity
Incorrect gap may cause intermittent signals.
Typical issues include:
Misalignment
Loose mounting bracket
Electrical wiring damage
Sensor contamination
Vibration-induced loosening
Incorrect sensing distance
Improper mounting is a frequent cause of false triggers.
Operators may notice:
Unexpected machine stops
Failure to stop at coil end
Alarm faults
Inconsistent detection
HMI error messages
Sensor malfunction may result in strip pulling out of feed system abruptly.
Proper installation requires:
Correct sensing distance
Stable mounting bracket
Shielded cable routing
Proper PLC input configuration
Secure electrical connection
Incorrect spacing reduces detection reliability.
Routine inspection should include:
Cleaning sensing face
Bracket tightness check
Cable inspection
PLC signal verification
Functional test during coil change
Preventive testing reduces unexpected stoppage.
Sensor failure may cause:
Sudden strip loss
Feed system shock
Pinch roll damage
Mechanical stress on gearbox
Production downtime
Reliable coil-end detection protects mechanical components.
When specifying a strip end proximity sensor, engineers evaluate:
Sensing distance
Response time
Environmental rating (IP protection)
Vibration resistance
Output type (PNP/NPN)
Operating voltage
Correct sensor selection ensures accurate and reliable coil-end detection.
The strip end proximity sensor supports:
Feed drive motor control
PLC logic sequencing
Coil change procedures
Operator alarm system
Machine protection system
It forms a key part of automated feed safety logic.
The strip end proximity sensor is a non-contact detection device used to identify the trailing end of coil strip in roll forming machines.
It:
Detects strip presence
Triggers feed stop
Prevents mechanical shock
Supports automated operation
Protects feed drive components
Though small in size, it plays a critical role in preventing damage and ensuring smooth coil changeover procedures.
It detects when the end of the metal strip passes the sensing point.
Inductive proximity sensors are widely used for metal detection.
The machine may not stop correctly at coil end, causing mechanical shock.
Yes. Loose mounting may cause false signals.
During routine coil change and electrical system maintenance.
Copyright 2026 © Machine Matcher.