RMK-9T Layer Analyser

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Plastic foils made of polyvinyl butyral (PVB) are required to produce laminated safety glass. Such foils connect glass panes in such a way that in the case of shattering the broken pieces of glass stick to the PVB layer and do not separate. For this safety function, a reliable compound is extremely important.

Adhesion works best when the moisture is between 0.4% and 0.65%.

If the water content exceeds this range, e.g., due to humidity entering the system from outside, the adhesion is reduced and the PVB layer can detach from the glass (delamination). In order to prevent this from happening, the water content needs to be closely monitored during the production, storage, transportation, and lamination of the PVB safety glass. Our foil monitor RMK-9T does just that.

The instruments uses near-infrared (NIR) radiation with a specialised method of alternating light. This leads to a particularly high stability in time, and interfering influences have only a negligible impact on the measured data.
The water content in the PVB layer is measured by observing the NIR absorption by the water. If needed, the layer thickness can also be measured.

The water content depends on the layer thickness. Therefore, it is possible to determine the absolute amount of water for different known values of thickness and take this dependence into account. With this method, the measured water content of the layer no longer depends on the layer thickness.

Measurement range: 0–1% moisture / additionally 0–2 mm thickness (upon request)
Accuracy: +/- 0.01% moisture / 0.02 mm thickness
Reproducibility: 0.005% / T90:1 sec.