US 6,203,738 B1Granted

Method for providing more uniform density in the manufacture of lightweight structural fiberboard panels

AssigneeMasonite Corporation

InventorDennis H. Vaders

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Abstract

A fiberboard mat, whether made by a dry process, a wet process, or dry/wet combination thereof, can be consolidated against a fiber displacement die, contacting and penetrating into a back major surface of the fiberboard mat, to provide fiber-void regions, to achieve a lighter panel, while achieving fiber savings and while maintaining structural integrity and substantially uniform density in the fiber-containing regions. The fiber displacement die includes a plurality of pointed projections that serve to laterally displace fibers, during consolidation of the mat. The displaced fibers are held in their displaced position during the consolidation of the fiberboard mat to provide a consolidated panel having substantially uniform density, or at least a substantially more uniform density, that varies substantially in caliper due to the fiber-void regions.

Claims9

Dependent claims

In a method of consolidating a fiberboard mat into a fiberboard panel comprising disposing a fiberboard mat between a first die and a second die during hot-press consolidation thereof into a structural panel;

and pressing said fiberboard mat between said first and second dies under heat and pressure to consolidate said fiberboard mat into a structural panel, the improvement comprising:
said second die including a plurality of spaced tapered projections extending vertically from a base thereof such that upon pressing under heat and pressure during consolidation of said mat into a fiberboard panel, said projections are pressed into said fiberboard mat, thereby causing some of the fibers in said fiberboard mat to flow laterally around an outer surface of said tapered projections during consolidation such that the resulting consolidated fiberboard panel includes fiber-void regions in one major surface thereof, corresponding in location to said projections on said die, while maintaining density uniformity in the fiberboard panel.

Dependencies are inferred from the claim text.