Method of producing a board of fibrous glass

Claim 1

A method of producing a thermal insulating roofing board of bonded, randomly positioned and spacedly related individual, discontinuous glass fibers with short bundles or strands of multiple glass filaments distributed in intermixed and bonded relation with the individual glass fibers throughout a narrow surface of the board, said method comprising drawing individual fibers from molten glass and directing them downwardly in spaced and randomly positioned relation toward a transversely traveling receiving surface, dividing the descending fibers into separate groups, said groups positioned successively in the direction of travel of the receiving surface, combining a dispersed settable binder with the fibers of each group, combining and intermingling short bundles or strands of definite predetermined lengths and containing hundreds of glass filaments with the individual fibers and dispersed binder of the group of fibers leading the succession of groups in the direction of travel of the receiving surface, while leaving other groups free of such strands, whirling the fibers of the leading group around a vertical axis to mix together the fibers, the strands, and binder thereof, maintaining the groups of fibers separated throughout their full downward travel, collecting the fibers, the dispersed binder of all groups and the fibrous glass strands of the leading group as a pack upon the receiving surface, compressing the pack and setting the dispersed binder to dimensionally stabilize the pack in board form by cohering the fibers throughout the pack and cohering the fibers and the strands in the surface stratum thereof constituting the fibers and strands of the leading group deposited last upon the pack in the movement of the receiving surface.

Claim 2

A method of producing a thermal insulating roofing board of bonded, randomly positioned and spacedly related individual, discontinuous glass fibers with short bundles or strands of multiple glass filaments distributed in intermixed and bonded relation with the individual glass fibers throughout a narrow surface of the board, said method comprising drawing individual fibers from molten glass and directing them downwardly in spaced and randomly positioned relation toward a transversely traveling receiving surface, dividing the descending fibers into separate groups, said groups positioned successively in the direction of travel of the receiving surface, combining a dispersed settable binder with the fibers of each group, combining and intermingling short bundles or strands of definite predetermined lengths and containing hundreds of glass filaments with the individual fibers and dispersed binder of the group of fibers leading the succession of groups in the direction of travel of the receiving surface, while leaving other groups free of such strands, whirling the fibers of the leading group around a vertical axis to mix together the fibers, the strands, and binder thereof, maintaining the groups of fibers separated throughout their full downward travel, collecting the fibers, the dispersed binder of all groups and the fibrous glass strands of the leading group as a pack upon the receiving surface, compressing the pack and setting the dispersed binder to dimensionally stabilize the pack in board form by cohering the fibers throughout the pack and cohering the fibers and the strands in the surface stratum thereof constituting the fibers and strands of the leading group deposited last upon the pack in the movement of the receiving surface.