Traversing unit for Measurement of Multiple Layer Thicknesses

Traversing unit for inline measuring during production

Plastic films are produced as wide continuous webs and then wound into rolls. Any flaw means not only that the film produced is defective but also that very expensive disposal is often necessary. This can generate additional costs of the order of several thousand euros for one day’s production.

A StraDex sensor traversing the moving web at a right angle to its direction of travel provides a means of early detection of such flaws.

This inline measuring system can determine both the total thickness of the material and the thickness of the individual layers, even at very high web speeds. Since the sensor functions in reflection mode, it can also measure the underside of the film, thus obviating the need for a second traversing sensor.

Slight “flutter” of the film due to the high web speed is of no consequence for this sensor because it constantly refocuses. Up to 4000 points are measured per second. Moreover, demands on the rigidity of the transverse are far less stringent that for other systems. The film product is continuously measured during production and constant quality thus assured.

ISIS sentronics offers traversing systems suitable for inline determination of layer thicknesses during the production process.