Extrusion: Non-Contact, Single-Sided Film, Sheet Gauge

Indev-ACT’s  ShadowMIKE provides non-contact, single-sided measurement for non-metallic film and heavy sheet. Other key applications for this unit include calendered sheet, composites, foam, nonwovens, coated substrates, embossed materials and rubber products raning from 50 to 5000 microns (2-200 mils).

This new sensor incorporates several features that are said to deliver greater measurement precision and speed. For example, the ShadowMIKE sensor uses a green LED laser diode array source that provides a uniform collimated beam that lasts longer than traditional LED light and provides high intensity, evenly-distributed lighting. This is projected across the apex of the product that is wrapped across the surface of a precision ground reference roll. The thickness of the product interrupts the laser path which is focused onto a charged couple device (CCD) array on the opposite side of the roll. The CCD array precisely measures the top surface of the beam to sub-micron precision, while an integrated induction sensor measures the exact distance of the sensor from surface of the precision role. The induction sensor includes thermo-electric temperature compensation to within ± 0.1C to negate any thermal interaction and provide accurate measurement through any temperature transitions. The final product thickness is computed as the difference between the inductive sensor and the optical measurements.

The ShadowMIKE has a data acquisition rate of 16,000Hz. This is more than 13 times greater than comparable sensors that sample at 1200Hz. This translates into greater measurement stability and precision, plus the ability to “see” product quality with exceptional resolution. With its small measurement spot size and high measurement rate performance, it provides a powerful insight into machine direction (MD) disturbances and profile streaks (CD), creating a valuable process analysis tool for quality improvement.

The ShadowMIKE scanner is further distinguished with its integrated precision-ground measurement backing roll (either steel or aluminum) and its low run-out characteristics. The choice of material depends on the application and accuracy requirements. The benefit of an integrated roll is that it eliminates additional installation costs of a separate roll, plus the on-going need to check and re-align the roll during production downtime.

Finally, many sheet and film processors have their own green programs designed to reduce their nuclear or ionizing sources within their operations. ShadowMIKE offers these processors a measurement upgrade option for those wishing to replace their beta or gamma gauges.