15
03 2026
Where should the melt pressure sensor be installed?
In extrusion processes, the mounting point of the melt pressure sensor is critical for measurement accuracy and line safety. Incorrect sensor positioning not only leads to measurement errors but can also cause equipment damage, die blockages, and production losses.
Therefore, pressure sensor mounting in extrusion lines should be evaluated from a process engineering perspective.
Correct Mounting Point for Melt Pressure Sensor
In extrusion systems, sensors are generally located in the following areas:
Extruder outlet
After the filter or screen changer
Die entry point
The most commonly preferred location is the measurement point closest to the die. This is because the die entry pressure directly affects production quality.
Accurate pressure measurement at the die entry point allows:
monitoring of flow stability within the die
keeping production quality under control
detecting sudden pressure increases at an early stage
Especially in film, sheet, pipe, and granule extrusion lines, this measurement point is used as the fundamental reference for process control.
Common Sensor Mounting Errors
Many measurement problems encountered in the field stem not from sensor failure, but from incorrect mounting practices.
The most common errors are:
Incorrect mounting depth
The sensor tip entering or falling too far behind the flow line impairs measurement accuracy.
Dead zone formation
The sensor mounting housing creating turbulence or a dead zone in the flow line can cause melt accumulation.
Unsuitable mounting surface
An uneven mounting surface puts mechanical stress on the sensor diaphragm.
Incorrect temperature conditions
Melt temperatures exceeding the sensor's operating range can shorten sensor life.
Therefore, the correct adapter, correct torque, and correct depth adjustment must be used during sensor mounting.
Why is Mounting in a Stable Flow Region Important?
Melt pressure sensors provide the most accurate results in regions where the flow is stable. Measurements taken in turbulent regions can result in fluctuating pressure values.
When selecting the sensor mounting location, the following criteria should be considered:
Avoiding dead space in the flow line
The sensor tip being level with the flow surface
Selecting a location free from mechanical vibration
Ensuring stable temperature distribution
When these criteria are met, the sensor provides both more accurate measurements and a longer lifespan.
The Role of Pressure Sensors for Process Safety
A correctly positioned melt pressure sensor acts as an early warning system in the extrusion line.
Thanks to the sensors:
mold blockages are detected early
filter fill level is monitored
extruder load is controlled
sudden pressure increases are detected
This both increases machine safety and reduces unplanned downtime.
Process-Oriented Mounting Support with MeltSensor
Each extrusion line has different process conditions. Therefore, sensor mounting should be planned on a process-specific basis, not as a standard application.
MeltSensor offers its users not only sensor supply but also:
process-based mounting recommendations
correct sensor selection
mounting depth and adapter recommendations
technical support for measurement problems encountered in the field
and other after-sales engineering support.
A correctly positioned melt pressure sensor ensures the safe operation of the extrusion line, improves production quality, and extends sensor life.