Morrison-knudsen Forest Products Company, Inc.

Joseph S Bleymaier

Thomas E Peters

Wilfred Farnworth

Methods are presented for continuous-line manufacture of composition board from furnish which is moved in a continuous-flow manner through a processing line and distributed for deposition at a uniform rate over a preselected area to continuously form a mat for compaction. Commercially economical production flow rates are achieved with a lightweight refined wood furnish to form fiberboard having directional properties without relying on pneumatic impulsion while uniformly distributed furnish is delivered substantially free of air turbulence effects enabling fiber orientation by means of an electrical field. Control of movement and accurate metering of furnish are facilitated by continuously over-feeding furnish into the processing line and returning excess furnish as part of an initial distribution of furnish over one dimension of the mat to be formed. The initially distributed furnish is confined in the remaining dimension while being continuously moved in the direction of the mat; the confined profile feed is metered, accelerated by mechanical contact, and then distributed over the full area of deposition. Lightweight fibrous furnish is delivered for screening to separate fiber clusters followed by electrical field orientation of individualized fibers and deposition. The furnish distributed over the forming area is moved along a flow path which is substantially normal to the surface of deposition.

Method for feeding and orienting fibrous furnish

Continuous-line methods and apparatus for orientation and uniform deposition of fibers to enhance directional properties in and production rates of fiberboard produced from lightweight fibrous furnish. A plurality of elongated rod electrodes are predeterminedly spaced over the area of fiber deposition to establish an electric field exerting a torque on discrete fibers tending to orient longitudinal axes of the fibers in the plane of the mat being formed and aligned with the machine forming direction for such mat. Placement of the rod electrodes and controlled rotation about their longitudinal axes yield a combination of electrical and mechanical forces to provide desired orientation and uniformity of deposition over the full area of deposition. Directional properties measured in the compacted and cured fiberboard establish that effective orientation ratios of longitudinal axes of fibers in the preferred direction of 1.2:1 and higher are made available working with lightweight fibrous wood material refined under steam pressure and are available at production rates which are commercially economic.

Orientation and deposition of fibers in the manufacture of fiberboard

Methods and apparatus are presented for continuous-line manufacture of composition board from furnish which is moved in a continuous-flow manner through a processing line and distributed for deposition at a uniform rate over a preselected area to continuously form a mat for compaction. Commercially economical production flow rates are achieved with a lightweight refined wood furnish to form fiberboard having directional properties without relying on pneumatic impulsion while uniformly distributed furnish is delivered substantially free of air turbulence effects enabling fiber orientation by means of an electrical field. Control of movement and accurate metering of furnish are facilitated by continuously over-feeding furnish into the processing line and returning excess furnish as part of an initial distribution of furnish over one dimension of the mat to be formed. The initially distributed furnish is confined in the remaining dimension while being continuously moved in the direction of the mat; the confined profile feed is metered, accelerated by mechanical contact, and then distributed over the full area of deposition. Lightweight fibrous furnish is delivered for screening to separate fiber clusters followed by electrical field orientation of individualized fibers and deposition. The furnish distributed over the forming area is moved along a flow path which is substantially normal to the surface of deposition.

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Columbia, MD, United States of America

Joseph S Bleymaier