摘要:
System and method for producing paper that employ an apparatus for measuring electrical characteristics of a fibrous composition. The apparatus comprises a plurality of conductivity (or resistance) detectors each comprising a sensor that is sensitive to the conductivity (or resistance) and the proximity of the material (e.g., fibrous composition) to the sensor. Measurements from the apparatus relate to the zeta potential of the fibrous materials in the composition. The zeta potential profiles corresponding optimized configurations of the sheetmaking process can be employed to monitor and control the process.
摘要:
A method for determining bending stiffness of a moving sheet using an on-line sheet bending stiffness sensor. The sensor continuously bends the sheet as it is being manufactured and, based upon the force required to bend the sheet, the amount of bending and the tension applied to the sheet, the sensor determines a parameter indicative of sheet bending stiffness. The resulting parameter can be correlated with conventional destructive laboratory tests of sheet bending stiffness.
摘要:
A sensor apparatus and electrode configuration within the sensor apparatus for measuring electrical characteristics of an aqueous fibrous composition. The electrode configuration includes an elongated ground electrode and at least one segmented electrode to form an array of measurement electrode cells. The electrode configuration further includes an array of reference electrode cells formed by a plurality of reference electrodes built into the array of measurement electrode cells. The measurement electrode cells and reference electrode cells have a different sensitivity to water weight of the aqueous fibrous composition and the same sensitivity to conductivity of the aqueous fibrous composition. The measurement apparatus obtains simultaneous resistive measurements from both measurement and reference cells and determines the ratio of the measurements such that the affects from conductivity is canceled out of the measurement ratio. The determined measurement ratio is used to obtain a measurement of the water weight of the aqueous fibrous composition by using previously determined characterization data of the water weight vs. a range of measurement ratios.
摘要:
A sensor imbedded roller for detecting changes in properties of a material and a measurement apparatus including a fixed impedance element coupled in series with a variable impedance sensor imbedded roller between an input signal and a reference potential (e.g. ground) is described. The sensor, which includes an electrode configuration, is imbedded into a roller such that when it rotates it comes in contact with the material being measured and its impedance varies. The variable impedance of the sensor relates to changes in property of the material being sensed which can then be related to changes in other physical characteristics of the material such as weight, chemical composition, and temperature. Sensor imbedded rollers can be placed in a sheetmaking machine to measure the pre-formed and post-formed paper product.
摘要:
A sensor, system and method for determining the various Z-directional properties of a sheet by measuring the caliper of a moving sheet of material at a plurality of pressures. The invention employs a caliper gauge and a set of pressure transducers that can measure and send signals indicative of the caliper as well as pressures exerted on the sheet. The signals are then digitized by an analog-to-digital converter and sent to a computer. The computer uses the compressibility data to construct a compression stress-strain diagram where the slope of the curve in the linear region of the curve is defined as the compression modulus of elasticity which can be empirically correlated to the tensile modulus of elasticity for various grades of paper. The tensile modulus of elasticity can be then used in various formulas to determine other Z-directional physical properties of the sheet, such as tensile strength, extensional stiffness and Scott bonding.
摘要:
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. Detectors coupled to the support detect and produce signals indicative of the force exerted on the support by the deflected sheet in at least three different directions. Each signal is processed to determine a physical characteristic, such as extensional stiffness, of the sheet of material in each of the three directions. The directional variations of the physical characteristic may be used to determine the fiber orientation angle and the degree of anisotropism of the sheet.
摘要:
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.
摘要:
A sensor is disclosed for sensing a physical property of a sheet material. The sensor includes a mechanism for supporting one side of the sheet along the periphery of a defined region and a mechanism for forcibly deflecting the sheet into the unsupported center of the defined region. A transducer may also be incorporated to sense the force required to deflect the sheet into the unsupported region and/or the distance that the sheet is deflected into the unsupported region. The sensor may be operatively coupled to a computer programmed to determine a physical property of the sheet based upon the sensed force and/or distance, such as the sheet failure strength.
摘要:
System and method for producing paper are provided. The system controls formation of wet stock comprising fibers on a moving water permeable wire of a de-watering machine that has means for supplying the amount of pulp from at least one source, means for adding an amount of non-fibrous additives to the wet stock, a refiner that is subject to a variable load and a headbox having at least one slice, wherein each slice has an aperture through which wet stock is discharged onto the wire. The system includes: (a) at least two water weight sensors that are positioned adjacent to the wire wherein the at least two sensors are positioned at different locations in the direction of movement of the wire and upstream from a dry line which develops during operation of the machine and the sensors generate signals indicative of a water weight profile made up of a multiplicity of water weight measurements; and (b) means for adjusting at least one of the motor load controller, the amount of non-fibrous additives added to the wet stock or amount of pulp supplied from the at least one source to cause the water weight profile to match a preselected or optimal water weight profile.
摘要:
An apparatus and method for obtaining fiber weight measurements in the wet end of a sheetmaking system and for verifying fiber weight measurements taken in the wet end of a sheetmaking system which includes a water weight sensor positioned beneath the wire in the wet end of the sheetmaking system for obtaining water weight measurements and load cells residing beneath the water weight sensor for weighing the wet end sensor and the wire with wetstock (total weight) and without wetstock (tare weight). In one embodiment, the water weight measurement and the tare weight measurement are subtracted from the total weight to obtain the fiber weight in the wetstock. In another embodiment, the water weight measurement is used to obtain an predicted fiber weight measurement and the determined fiber weight is used to verify the predicted fiber weight measurement and the accuracy of the water weight measurement device.