Abstract: A system for drying a moving sheet includes a housing, support means connected to the housing to support heater bulbs adjacent to moving sheet and a power supply connected to the bulbs. The heater bulbs are located so that at least part of the radiation from each of the bulbs travels directly to the sheet without passing through another bulb while from a plurality of bulbs part of the radiation travels in a straight line to the sheet and before reaching the sheet the radiation passes between two other bulbs without passing through another bulb.

Abstract: A sensor for detecting directional variations in a physical characteristic of a moving sheet of material is disclosed. The sensor has a support for supporting the moving sheet. The support defines an open region into which the moving sheet is deflected by a deflector. The support is rotatable to allow detectors coupled to the support to detect and produce signals indicative of the force exerted on the support by the deflected sheet in a number of different directions. Each signal is processed to determine a physical characteristic, such as extensional stiffness, of the sheet of material in each direction. The directional variations of the physical characteristic may be used to determine the fiber orientation angle and the degree of anisotropism of the sheet.

Abstract: An on-line scanning sensor system includes first and second horizontally extending guide members connected by side members to define a rigid box-like frame, and a support structure for suspending the box-like frame via vibration-absorbing devices such that vibrations are substantially attenuated before reaching the guide members. Further, the system includes a carriage mounted on the first guide member for scanning motion across a traveling web of sheet of material, and interferometer components mounted to the carriage for splitting and recombining infrared light and for directing a collimated beam of the recombined light onto the traveling sheet. Still further, the system includes a detector for receiving light from the interferometer components during scanning.

Abstract: A sheet manufacturing system having a steam profiling bar, a moisture profiling bar, a moisture sensor and a computer is disclosed. The computer is programmed to cause the correct amount of steam or water to be applied on a slice-by-slice basis based upon the mositure content profile data generated by the moisture sensor as compared against a preprogrammed, desired moisture content profile. The computer is programmed in such a way as to cause either steam or water, but not both, to be applied as needed to any given portion of each individual slice to achieve the desired moisture content profile. Thus, the combined application of both steam and water to the same portion of the sheet, and the nullifying effects thereof, are avoided, resulting in the use of less steam and less water while still providing full control over the moisture content profile with only one moisture sensor.

Abstract: A device for characterizing the formation of a sheet material is described. The device comprises a basis weight sensor for measuring the basis weight of the sheet material as the material passes through the sensor and signal processing circuitry which receives a signal from the basis weight sensor indicative of the measured basis weight and which produces three types of outputs, which outputs characterize: (1) the magnitude of variation in the sheet basis weight; (2) the strength of the weakest portion or portions of the sheet; and (3) the size of the flocs comprising the sheet. The basis weight sensor includes a light pipe which is held against the sheet, as the sheet moves through the sensor, and which directs a small spot of light transmitted through the sheet to a light detecting device. The magnitude of variation in the sheet basis weight is computed to be proportional to the true root-mean-square variation in the basis weight of the sheet.

Abstract: A self-cleaning steambox including means for directing jets of cleaning fluid across the steambox faceplate to remove obstructing material from the steam holes.

Abstract: A contacting caliper gauge measures the thickness of a moving sheet material. The gauge has two sheet contacting pads, one on either side of the sheet. At least one sheet contacting pad of the caliper gauge is aerodynamically designed to limit and/or reduce the tendency of boundary layer air travelling with the sheet to raise the sheet contacting pad off of the sheet surface. The caliper gauge also includes an electromagnetic proximity sensing device for determining the distance between the caliper pads, and thereby the sheet thickness. The gauge includes a caliper pad having an electromagnetic core having two pole faces mounted to that portion of the caliper pad remaining in closest proximity to the moving sheet surface. In on embodiment, the caliper pad has a vacuum notch which pulls the rear half of the pad, and in particular the rear end of the pad, in close proximity to the moving sheet.

Abstract: A moisture control system including an apparatus for discharging independently variable amounts of working fluid toward selected cross-directional sections of a calendered sheet material after the material has left the calender stack and before it is taken up by a collection device. The apparatus includes a plurality of valves spaced across the width of the calendered material to control the amount of fluid applied to each section. Nozzles provided on the valves direct the fluid from the valves toward a surface of the calenderable material. The system permits cross-directional equalization of the moisture content of the calendered material without affecting other physical properties of the sheet, such as sheet finish.

Abstract: A single sided reflectance sensor having an optical arrangement which permits accurate measurements of select physical properties of a moving sheet. The sensor comprises a protective enclosure, positioned adjacent to a sheet surface, containing an electromagnetic radiation source disposed to project an incident beam onto the sheet surface, a reflectance sensing means for sensing the intensity of the reflected portion of the incident beam, and a planar convex lens, located between the source and the sheet. The shape and orientation of the lens source and the sheet. The shape and cross-direction and/or render the sensor substantially insensitive to sheet flutter.

Abstract: A contacting caliper gauge measures the thickness of a moving sheet material. The gauge has two heads, one on either side of the sheet. The sheet contacting pads of the caliper gauge are aerodynamically designed to limit and/or reduce the tendency of boundary layer air travelling with the sheet to raise the sheet-contacting pads off of the sheet surfaces.

Abstract: The apparatus and method of the present invention provide means by which non-warped corrugated paperboard sheet may easily and consistently be produced. The cross-directional moisture content profiles of the top and bottom liners of the corrugated sheet are automatically monitored, and controlled with independently operable water jets such that the liners have approximately equal machine and cross-direction moisture content profiles. The moisture content profiles of the liners are controlled to equalize the machine direction and cross-directional stresses created within the liners as they dry out, thereby producing non-warped corrugated paperboard sheet.

Abstract: A gloss control system is provided for controlling the surface gloss of a sheet material. The system provides separate and independent control of heat and moisture applied to the sheet material, rather than the fixed ratio of heat and moisture applied by previous steam shower systems. Heat may be applied by a plurality of infrared lamps whose radiation is directed to the sheet material surface. A plurality of upwardly facing atomizing spray nozzles act to provide streams of atomized water directed at the surface of the sheet material. A scanning gloss sensor detects the degree of surface gloss of the sheet material at various cross-directional locations and control the application of heat and moisture in accordance with the detected surface gloss to thereby achieve a desired gloss profile.

Abstract: A contacting caliper gauge for measuring the thickness of a moving sheet. The gauge has two extendible members located opposite one another on opposite sides of the sheet. Each extendible member forces a caliper pad into contact with the sheet. Each pad is connected to the extendible member so that the rear portion of the pad exerts greater pressure on the sheet than the front portion. Each pad is also preferably tapered so that the rear end surface and the sheet contacting surface form a sharp edge at the rear of the pad and an angle of 90 degrees or less. Both the shape of the pad and its positioning with respect to the extendible member act to limit build up of adhesive material on the sheet contacting surface of the pads.

Abstract: In an on-line scanning sensor system, certain components of an FT-IR interferometer are isolated from vibrations that cause inaccuracies in measurements provided by the system, thereby allowing the sensor system to be used on-line in manufacturing environments. More particularly, vibration-absorbing suspension devices suspend selected interferometer components such that the center of suspension of the suspended interferometer component is substantially coincident with the center of gravity of the suspended components.

Abstract: A sheet tension measuring device is disclosed for measuring the tension of a moving sheet wherein a moving sheet is accurately positioned with pinchers at 2 spaced locations. The sheet is deflected between these pinchers from its nominal straight line path, and the amount of deflection and deflecting force are measured. The pinchers iron out any wrinkles in the sheet as the moving sheet slides through the pinchers. Sheet tension is computed based upon the measured deflection force and deflection distance. The resulting measurements of local sheet tension are used to correct nondestructive sheet strength measurements. A device and method are also disclosed for nondestructively determining the sheet strength and the extensional stiffness of the sheet in the machine direction and in the cross-direction.

Abstract: A method for controlling high-speed sheetmaking machine after abrupt process changes and during start-up periods and the like, includes operating a scanning sensor to periodically traverse back and forth across a sheet in the cross direction to detect values of selected sheet property along each scan while the cross-directional width of each scan is controlled to be substantially less than the width of the sheet being scanned.

Abstract: An apparatus, including a manifold pipe, for applying variable amounts of steam to sections of a calenderable material to control certain properties of the material such as gloss. Built-in steam flow control valves are provided along the manifold pipe to control the amount of steam applied to each section. Bucket nozzles provided on the valves decrease the velocity of the steam jetted from the valves and eliminate any condensate present in the steam before discharging the steam against a surface of the calenderable material. Condensate which may form on the apparatus may be channeled away from the calenderable material by a pair of gutters.

Abstract: A system for detecting optically-sensitive properties of sheet materials during manufacture includes a first group of bundles of optical fibers that convey light to selected transmitting locations adjacent one face of the sheet material. The system further includes a second group of bundles of optical fibers that collect and convey light transmitted through the sheet material to a light detector. The light detector measures the intensity of light received from each of the bundles of the second group to provide measurements of optically-sensitive properties of the sheet material at selected cross-directional locations.

Abstract: An apparatus and a method for controlling the thickness of coatings on webs at a plurality of cross-directional positions while a coating procedure is taking place. The deflection of the metering element is controlled automatically in response to measurements of the uncoated and coated web that determine the thickness of the coating being applied at a plurality of cross-directional positions. In one preferred embodiment, a bimetallic member having a plurality of separated tongue-like extensions corresponding to cross-directional positions along the blade is used, the tongue-like extensions pressing on the back of the blade at their ends in response to heat applied dependent upon the determined thickness of the coating being applied. In another embodiment, pneumatic actuators whose pressure may be varied in response to the determined thickness are used to adjust the position of the metering element at a plurality of cross-directional positions to locally vary the thickness of the applied coating.