W-Checker hot-melt detection sensor

The Width-Checker (WCHecker) is a sensor that checks the presence of hot-melt adhesive on pieces in transit.

The check is made not only on the presence or absence of the adhesive, but also on the width of the deposited section, therefore the WChecker is particularly suitable to check the quality of the gluing on lines that carry out the continuous coating of the glue.

The width is measured by a specific thermal sensor that simultaneously measures the temperature in 8 spots of the deposited section, verifying that the value read in each of them corresponds to the “cold” and “hot” conditions set by the programming software.

With WChecker it is therefore possible not only to check the presence of a hot-melt strip, but also to verify that the width corresponds to what is required, pointing out any widening or narrowing.

The temperatures of the 8 zones are displayed in real time on just as many multicolour LEDs, which indicate the circumstances of the cold zone (blue LED), the hot zone (yellow LED) and the very hot zone (white LED).

The WChecker is provided with a Modbus RTU/RS485 interface operating at 9600 bps, and can therefore be connected to systems using this same standard.

Connections are facilitated by the presence on the WChecker of an RJ45 connector that can be connected to common Ethernet cables. For connections between the Ethernet cable and the electrical panel (power supply, alarm signal, Modbus line, etc.), a special CB-CHECKER interconnection board is provided for DIN rails with an RJ45 connector and screw terminals.

The operating parameters can be set by using the programming software:

  • Synchronisation between gun opening/closing and actual reading. This function allows to take into account the distance between the gun and the WChecker sensor, compensating for reading delays caused by the time it takes for the adhesive to transit from the dispensing spot to the verification spot
  • Sensor response speed (switching time between non-alarm and alarm and vice versa)
  • Temperature threshold for cold zone/hot zone discrimination
  • Hysteresis between cold zone and hot zone temperature
  • Temperature difference between hot zone (yellow LED) and very hot zone (white LED)
  • Which temperature zones are to be considered hot and which are to be considered cold

The video shows the use of W-Checker sensor in a hot-melt coating line. In the video it is simulated the reduction dispencing of the glue to show the changing of the LEDs state.

The WChecker sensor is equipped with an optics capable of covering an angle of about 55°, therefore it is possible to decide the size of the area to be framed according to the distance from the adhesive strip.

The side image shows the size of the object framed on the basis of the reading distance.