Paper and Converting Applications
The cast aluminium MCT 360 is the usual choice when a fixed moisture or coat-weight measurement is required as it is robust in the event the sensor could be knocked, in addition it is fitted with an integrated cooling panel, making it easy to add a vortex cooler should this be necessary. The sensor uses smart sensor technology, all process inputs/outputs are direct to/from the sensor head making installation and networking a simple operation. Gauge parameters can be programmed using a PC or an operator interface. The MCT 330HD sensor is a heavy duty stainless steel option well suited to high temperature and high humidity conditions, this unit requires the installation of a separate processor/display unit in a more temperate location. An ExD explosion-proof sensor is available if the sensor is to be mounted in a potentially explosive atmosphere.
The Guardian scanning system is designed to measure coat weight and moisture profiles across a moving web. The Guardian system comprises a lightweight sensor in a pressed steel enclosure, a processor/display unit, an automated scanning frame and PC with SFS profile s/w. A single system can generate up to 3 profiles simultaneously.
High temperature locations may require a vortex cooler.
A Product loss sensor can be installed to hold the moisture or coat-weight measurement should a web break occur.
An alarm board may be fitted to enable an alarm output if the measurement exceeds a high or low limit or if the gauge malfunctions.
Gauge outputs, Operator Interface & Display
Up to 3 x 4-20MA or 0-10V
RS232 or RS485
Optional Operator Interface and display unit
NIR can be used to measure moisture within, or on the surface of a web based product. The latter measurement is useful in determining a coat weight at the wet end especially if the dry coating is organic and the substrate is also organic. This is due to the fact it will not be influenced by variations in the substrate. Measuring the moisture content at the exit of a coater is the only way of measuring a non-organic coating such as clay on paper. Measurements are reliable provided the solids ratio doesn’t vary. Measurement of wet coat weight provides the possibility of both feed forward and feedback control. Dry end measurements are most accurate if the coating has a unique absorption or if the substrate is at a constant thickness (very flat). Moisture levels in card and paper needs to be carefully monitored and controlled to ensure dimensional stability and that it matches up to specification for the next stage of the process e.g. printing or lamination.