Door and Frame Molded of Fibrous Mineral Material

This invention relates generally to doors of the type used at entrances of houses, and more particularly, to such doors and frames molded of fibrous mineral material.

Residential entrance doors are generally made out of wood. Increasing energy costs are creating a market for more thermally resistant doors than wood. Plastic foam doors encased in steel are highly conductive at the edges.

U.S. Pat. No. 1,867,575 discloses molding a door out of cellulose fibers.

In accordance with the invention, a door and frame molded of fabricated fibrous mineral material such as mineral, glass, slag, or rock wool and a binder is provided.

The invention is more fully described hereinafter, reference being had to the accompanying drawings in which:

FIG. 1 is an elevational view of a door constructed in accordance with the invention, with portions broken away;

FIG. 2 is a fragmentary sectional view taken generally along the line 2--2 of FIG. 1;

FIG. 3 is an elevational view of a door frame constructed in accordance with the invention; and

FIG. 4 is a sectional view taken generally along the line 4--4 of FIG. 3.

With reference to the drawings, FIGS. 1 and 2 show a door 10 constructed in accordance with the invention and including a core or main body portion 12 molded of fabricated fibrous mineral material, preferably glass wool impregnated with about 20% by weight of a phenolic resin binder such as phenol-urea-formaldehyde, to a density of from 6 to 20, preferably about 10, pounds per cubic foot.

The core 12 is machined for reception of hinge plates, as at areas indicated by numerals 14, 15 and 16, and is machined for a doorknob, latch, and lock assembly, as at an area indicated by numeral 18. Holes 20 are drilled in the core, completely or nearly therethrough, in rows spaced about six inches apart, and all around the edges at about one-inch intervals, and in rows spaced about one-inch apart in the hinge and doorknob-latch-lock areas.

Polyester resin is applied by brushing or spraying resin on the core 12 or by dipping the core 12 in a tank full of resin. The resin soaks into the core 12 to produce a reinforced resin skin 12a adjacent all outer surfaces of the core and to produce reinforced resin columns 12b at all holes 20. Control of the penetration of the resin into the core 12 can be accomplished by varying the density of the core 12, modifying the viscosity of the resin, controlling the gel time, or varying the length of time that the core 12 is exposed to the resin. Deep penetration around the edges provides strength and allows the door to be trimmed if necessary, with the same tools as used for wood.

Any suitable finish coat 22 may be applied over the resin-treated core 12. The coat 22 may be a pigmented gel coat, paint, or a veneer of plastic, metal, or wood.

FIGS. 3 and 4 show a frame 24 provided to complement the door 10. The frame 24 comprises side members 24a and 24b and a top member 24c all identical in cross section, opposite ends of the top member 24c being mitered respectively to upper ends of the side members 24a and 24b. The side member 24a is notched at areas identified by numerals 25, 26, and 27 for reception of hinge plates, and the side member 24b is notched at an area identified by numeral 28 for reception of a latch plate. The frame 24 is made similarly to the door 10. Each of the members 24a, 24b, and 24c includes a core, such as core 24d for the member 24a, molded of fabricated fibrous mineral material, preferably glass wool, impregnated with a phenolic resin binder such as phenol-urea-formaldehyde, and subsequently treated with polyester resin which penetrates the core to produce a reinforced resin skin such as 24e adjacent outer surfaces of the core. Holes such as the hole 30 may be drilled out before application of the polyester resin, whereby reinforced resin columns such as the column 24f may be produced to strengthen the member 24a at the hinge plate areas 25, 26, and 27 and the member 24b at the latch plate area 28.

Various modifications may be made in the structure shown and described without departing from the scope of the invention as set forth in the following claims.