Abstract: In a papermaking or like operation wherein fibers are supplied to a headbox in a foamed furnish, a method of controlling furnish flow including the steps of controllably advancing the furnish along a flow path to the headbox, measuring the volume flow rate of furnish through a fixed cross-sectional area in the path with a magnetic flowmeter, combining the flow rate measurement at least with measured values of furnish density and pressure in the path and with a reference pressure value to obtain a corrected volume flow rate value, and controlling the advance of furnish in the path upon departure of this corrected value from a desired value so as to change the corrected value toward the desired value. A temperature measurement can also be combined with the other measured values, and with a reference temperature value, in obtaining the corrected flow rate value.

Abstract: Apparatus and method for the manufacture of a non-woven fibrous web such as paper from a dispersion of fibers in a foamed liquid in which fiber furnished in a foamed liquid comprising a solution of surfactant in water is discharged from a headbox into the nip of a twin forming wire prior to its passage over a forming roll. The water-surfactant solution is drained from the web and recycled as a foamed liquid containing about 65% air in the form of bubbles of from about 20 to about 200 microns in diameter. The foamed liquid is directed into a mix tank wherein a slurry containing fiber at 20% to 55% solids is added and mixed. The mixture is pumped to the headbox and into the nip of the forming wires.

Abstract: Apparatus and method for the manufacture of a non-woven fibrous web such as paper from a dispersion of fibers in a foamed liquid. In a preferred embodiment, a solution of surfactant in water is initially discharged from a headbox into the nip of a twin forming wire prior to its passage over a curvilinear path defined by a forming roll. The water-surfactant solution is caused repeatedly to pass through the outer one of the twin forming wires until there is created, and stored in a silo, a foamed liquid containing about 65% air in the form of bubbles of from about 20 to about 200 microns in diameter. The foamed liquid is directed from the silo into a mix tank wherein a slurry containing fibers at 20% to 55% solids is added and mixed. The mixture is pumped to the headbox and into the nip of the forming wires. The outer wire retains the fibers while passing and again foaming the liquid for return to the silo and the mix tank for addition of fibers and return to the headbox.

Abstract: Apparatus and method for the manufacture of a non-woven fibrous web, such as paper, from a dispersion of fibers in a foamed liquid. In a preferred embodiment, a solution of surfactant in water is initially discharged from a headbox into the nip of a twin forming wire prior to its passage over a curvilinear path defined by a forming roll. The water-surfactant solution is caused repeatedly to pass through the outer one of the twin forming wires until there is created, and stored in a silo, a foamed liquid containing about 65% air in the form of bubbles of from about 20 to about 200 microns in diameter. The foamed liquid is directed from the silo into a mix tank wherein a slurry containing fibers at 20% to 55% solids is added and mixed. The mixture is pumped to the headbox and into the nip of the forming wires. The outer wire retains the fibers while passing and again foaming the liquid for return to the silo and the mix tank for addition of fibers and return to the headbox.

Abstract: Apparatus and method for the manufacture of a non-woven fibrous web, such as paper, from a dispersion of fibers in a foamed liquid. In a preferred embodiment, a solution of surfactant in water is initially discharged from a headbox into the nip of a twin forming wire prior to its passage over a curvilinear path defined by a forming roll. The water-surfactant solution is caused repeatedly to pass through the outer one of the twin forming wires until there is created, and stored in a silo, a foamed liquid containing about 65% air in the form of bubbles of from about 20 to about 200 microns in diameter. The foamed liquid is directed from the silo into a mix tank wherein a slurry containing fibers at 20% to 55% solids is added and mixed. The mixture is pumped to the headbox and into the nip of the forming wires. The outer wire retains the fibers while passing and again foaming the liquid for return to the silo and the mix tank for addition of fibers and return to the headbox.