Abstract: The apparatus and method of the present invention generates and controls an air-atomized spray, for application of moisture to a moving sheet, such as paper or converted paper products (e.g. corrugated board). The air-atomized water spray is generated by mixing a metered quantity of water with a constant air volume. In a representative embodiment the water flow is metered by adjusting the axial position of a shut-off needle relative to a circular control orifice. The needle is positioned by pushing and pulling upon it with a thermally-expanded metallic element. The thermally expanded element is heated directly or indirectly, at a controlled rate, to produce the desired needle movement and resultant water flow. A series of such controllable nozzles can be mounted across the width of a sheet to permit localized, metered moisture application to each cross-machine control zone.

Abstract: The system and method of the present invention determines glue-line characteristics, such as temperature, of corrugated board. Components of an on-line glue sensor's output signal that are oscillating at the fluting frequency are isolated. The components of the sensor output signal that are sensitive to glue, which is only present on the tips of the flutes, oscillate at the fluting frequency. Those variations in the sensor output signal that are not oscillating at the fluting frequency are canceled out, while those that are oscillating at the fluting frequency are isolated and amplified, facilitating an accurate estimate of their amplitude. The output signal of an infrared absorption sensor will provide an improved on-line starch measurement for corrugators. The incremental amount of infrared radiation that is absorbed by starch and/or water in the glue-lines is isolated from the predominant, more random background absorption due to cellulose and water in the paper substrate.