Abstract: Apparatus and process for controlling the basis weight of paper produced in a papermaking machine are provided. In the papermaking process, a major portion of the paper stock flows through a first line that is controlled by a thick stock valve and a minor portion of the stock flow from the stuff box to the headbox is diverted through a second line that is regulated by a second valve (e.g., vernier valve). The thick stock valve is controlled by the dry end basis weight and the second valve responsive to measurements of the basis weight of the wet stock at the wire. The second line and control valve along with the wet end basis weight measurements form a fine control loop with fast response time whereas the first line and control valve that is responsive to dry end basis weight measurements form a course control loop. The dual control loops enable fast and actual basis weight control.

Abstract: A sensor and method is provided for measuring one or more select components of a material. In one embodiment, a method measures the components by emitting electromagnetic radiation at the material and detecting the intensity of the emerging radiation at separate locations from the source. In another embodiment, a sensor provides a radiation source for emitting radiation at a sheet, a plurality of detecting means, offset substantially the same from the source, for detecting radiation after interaction with the sheet and first and second reflectors for directing the radiation so that the radiation makes multiple interactions with the sheet when moving from the source to the detecting means. The invention can accurately measure the select components (e.g., moisture) of different grades of paper by eliminating the effects of the scattering power and determining absorption power at each band of the spectrum considered necessary for a particular measurement.

Abstract: A sheet-gauging apparatus for determining properties of a moving sheet of material includes a frame having parallel upper and lower horizontal supports extending above and below the sheet in a direction transverse to the direction of travel of the sheet. Upper and lower tracks are carried by the upper and lower supports, respectively, each of the tracks including a flat upper surface and a lower surface having tapered end portions. Upper and lower carriages are mounted on the upper and lower tracks, respectively, for bidirectional travel along the tracks, each of the carriages including upper wheels in rolling contact with the upper surface of the track and lower wheels in rolling contact with the tapered end portions of the lower surface of the track. Displacement of the carriages in the directions orthogonal to the direction of carriage travel is thereby minimized.

Abstract: Apparatus utilized in the continuous manufacture of sheet material, such as paper, includes a frame having at least one hollow beam for carrying means such as sheet-gauging heads operatively associated with the sheet material being fabricated. Thermal stability of the at least one hollow beam is enhanced by circulating fluid within the beam. Fluid displacement means which may be in the form of a series of inserts disposed end-to-end within the hollow beam define with the interior wall of the beam a fluid conduction channel. The fluid displacement means may also include generally helically oriented guides projecting into the fluid conduction channel for inducing turbulence in the circulating fluid.