Abstract 1. A process for the production of a composition board which comprises wetting a quantity of hogged wood materials until the moisture content of said wood materials is raised to approximately thirty percent on an oven dry basis, then grinding said moisturized wood materials under such conditions as to provide a fiber portion wherein approximately ninety-five percent of the fibers have a length of less than one-half inch and wherein the lengths of said fibers are also about ten times the width and thickness thereof, drying the ground moisturized wood material until the moisture content thereof is reduced to about five percent on an oven dry basis, separating the dried ground wood material into two fractions, the first of said fractions being of said fibers and having a bulk density of about four to ten pounds per cubic foot, the second of said fractions being of fine wood particles having a bulk density of about six to twelve pounds per cubic foot and small enough to pass through a twenty mesh screen, mixing a quantity of fibers with an adhesive mixture to provide a fiber-adhesive mixture for the core of said composition board, separately mixing a quantity of the fine wood particles with an adhesive to provide a fines-adhesive mixture for the surface layers of said composition board, forming a three layered mat by placing a layer of fiber-adhesive mixture on a layer of fines-adhesive mixture and being of substantially the same thickness as the lowermost layer of fines-adhesive mixture, positioning the three-layered mat between two screens, one on top of the mat and the other on the bottom of the mat, compacting the three-layered mat under elevated temperatures and pressures for a period of time not exceeding six minutes with a press closing time of less than forty seconds, and thereafter separating the screens to product a composition board with a nearly uniform density core between surface layers of substantially higher density.
A process for the production of a composition board which comprises wetting a quantity of hogged wood materials until the moisture content of said wood materials is raised to approximately thirty percent on an oven dry basis, then grinding said moisturized wood materials under such conditions as to provide a fiber portion wherein approximately ninety-five percent of the fibers have a length of less than one-half inch and wherein the lengths of said fibers are also about ten times the width and thickness thereof, drying the ground moisturized wood material until the moisture content thereof is reduced to about five percent on an oven dry basis, separating the dried ground wood material into two fractions, the first of said fractions being of said fibers and having a bulk density of about four to ten pounds per cubic foot, the second of said fractions being of fine wood particles having a bulk density of about six to twelve pounds per cubic foot and small enough to pass through a twenty mesh screen, mixing a quantity of fibers with an adhesive mixture to provide a fiber-adhesive mixture for the core of said composition board, separately mixing a quantity of the fine wood particles with an adhesive to provide a fines-adhesive mixture for the surface layers of said composition board, forming a three layered mat by placing a layer of fiber-adhesive mixture on a layer of fines-adhesive mixture and being of substantially the same thickness as the lowermost layer of fines-adhesive mixture, positioning the three-layered mat between two screens, one on top of the mat and the other on the bottom of the mat, compacting the three-layered mat under elevated temperatures and pressures for a period of time not exceeding six minutes with a press closing time of less than forty seconds, and thereafter separating the screens to product a composition board with a nearly uniform density core between surface layers of substantially higher density.
Claim 2
Dependent Claim
322 words
A process for the production of a composition board which comprises wetting a quantity of hogged wood materials until the moisture content of said wood materials is raised to approximately thirty percent on an oven dry basis, then grinding said moisturized wood materials under such conditions as to provide a fiber portion wherein approximately ninety-five percent of the fibers have a length of less than one-half inch and wherein the lengths of said fibers are also about ten times the width and thickness thereof, drying the ground moisturized wood material until the moisture content thereof is reduced to about five percent on an oven dry basis, separating the dried ground wood material into two fractions, the first of said fractions being of said fibers and having a bulk density of about four to ten pounds per cubic foot, the second of said fractions being of fine wood particles having a bulk density of about six to twelve pounds per cubic foot and small enough to pass through a twenty mesh screen, mixing a quantity of fibers with an adhesive mixture to provide a fiber-adhesive mixture for the core of said composition board, separately mixing a quantity of the fine wood particles with an adhesive to provide a fines-adhesive mixture for the surface layers of said composition board, forming a three layered mat by placing a layer of fiber-adhesive mixture on a layer of fines-adhesive mixture and being of substantially the same thickness as the lowermost layer of fines-adhesive mixture, positioning the three-layered mat between two screens, one on top of the mat and the other on the bottom of the mat, compacting the three-layered mat under elevated temperatures and pressures for a period of time not exceeding six minutes with a press closing time of less than forty seconds, and thereafter separating the screens to product a composition board with a nearly uniform density core between surface layers of substantially higher density.