SPECIFICATIONCompression molded door assemblyAttempts have been made in the past to construct various types of door assemblies. A door assembly which is installed as an exterior door should be dimensionally stable to reduce energy losses through the opening. Relatively severe temperature differentials occur on such exterior door assemblies. One of the major problems with prior art door assemblies has been excessive deflection and warping caused by such temperature differentials. Traditional wood doors suffer from splitting and cracking in addition to long-term moisture absorption which results in warping.
Another problem which has not been resolved by prior art door assemblies is the appearance of the door. In situation where simulated wood door appearances have been desired, attempts have been made to obtain the "wood" appearance through the use of veneers and other surface treatments. Customers are generally familiar with the texture and the differences in graining of a wood door. Therefore, unless this same type of texture and graining, for example edge graining, is duplicated, the wood simulated door assembly is unsatisfactory from an appearance viewpoint.
Another problem is the installation of a door assembly. In the rehabilitation market and even in new construction, it is often necessary to trim the door assembly prior to installation within the door frame. This was often difficult to do when using prior art door assemblies.
According to the present invention there is provided a door assembly comprising, in combination, a rectangular frame, a pair of opposed compression molded skins mouned on said frame, and a foamed core positioned within said frame between said opposed compression molded skins, said skins each having an outer side and an inner side, said outer side of each skin defining a molded textured pattern simulating the grain and texture of a wood door, said frame extending outwardly from at least a portion of the edge of said skins, whereby, such frame may be trimmed for insertion in a door opening.
The present invention may be in the form of a compression molded door assembly having compression molded skins which are mounted on a rectangular perimeter frame. A texture is molded on the exterior surfaces of the skin to simulate both the texture and the grain of a wood door. A textured surface may also be molded on the interior side of each skin. The perimeter frame extends outwardly from the edges of the skins to allow for trimming of the door assembly.
The non-rigid core may be a foamed core, for example a urethane foam, positioned within the frame in an adhering relationship with the opposed compression molded skins and the frame.
The present invention provides a compression molded door assembly having a close simulation on its exterior to a wooden door, both in texture and grain. The compression molded door assembly of the invention has the advantage that it can be trimmed for insertion in an opening.
A further advantage of a compression molded door assembly of the present invention is that it resists permanent deflection and warping when exposed to temperature and humidity differentials.
Figure 1 is an elevational view of a compression molded door assembly, according to the present invention, showing the simulated wood texture in the lower right-hand corner;Figure 2 is the reverse side of one panel or skin of the compression molded door assembly shown in Figure 1 and further showing an inner texture in the lower right-hand corner;Figure 3 is an enlarged fragmentary section view taken along the line 3-3 of Figure 1;Figure 4 is an enlarged fragmentary section view taken along line 4-4 of Figure 1;Figure 5 is an enlarged fragmentary section view taken along the line 5-5 of Figure 1;Figure 6 is an enlarged fragmentary section view taken along the line 6-6 of Figure 1;Figure 7 is an enlarged fragmentary section view taken along the line 7-7 of Figure 1;Figure 8 is an enlarged fragmentary section view taken along the line 8-8 of Figure 2; andFigure 9 is an enlarged fragmentary view taken along the line 9-9 of Figure 2.
A compression molded door assembly, according to the present invention, is generally indicated by the reference number 20 in Figure 1.
The compression molded door assembly 20 includes a pair of opposed compression molded door panels or skins 21,22, which are attached to a perimeter frame 23. The interior of the perimeter frame 23 is filled with a foam core 24 which is adhered to the skins 21, 22.
Each of the skins 21,22 is a compression molded sheet molding compound (SMC) panel, which includes (5% to 40% fibrous glass reinforcement, by weight, and 10% to 40% inert mineral filler, by weight, in polyester resin. The inert filler can be, for example, calcium carbonate or alumina trihydrate. In some embodiments, the material may also include ultraviolet stabilizers and fire retardant additives in the composition.
Each of the skins 21, 22 has a thickness of between .050 inch (0.127 cm) and .120 inch (0.305 cm). The present embodiment shown inFigure 2, has a skin thickness of 0.070 inch (0.178 cm).
Referring to Figure 1, an exterior side 26 of the skin 21 includes a molded wood grain texture 27.
The texture 27 simulates both from a texture viewpoint and a graining viewpoint that of a wood door, which has been assembled from wood components consisting of stiles, rails, raised and carved panels. The texture 27 on the exterior side 26 is between .003 inches (0.008 cm) and .009 inches (0.023 cm) in depth.
Referring to Figure 2, which depicts the inner side 28 of the skin 21, a random texture 29 is molded into the skin 21. The random texture 29 on the inner side 28 has a depth of between .003 inch (0.008 cm) and .005 inch (0.013 cm). Therandom texture 29 aids in the adherence of the foam core 24 to the opposed skins 21, 22.
The perimeter frame 23, in the present embodiment, is a wood perimeter frame constructed of finger-jointed pine. The perimeter frame 23 is adhesively bonded to the inner and outer compression molded polyester skins 21, 22.
The core 24 comprises a rigid urethane foam having a density of .8 pounds per cubic foot (12.815 kg/m3) to 3.5 pounds per cubic foot (56.065 kg/m3).
Referring to Figure 1 , the perimeter frame 23 extends outwardly from the edge 31 of the panels of skins 21, 22. The extension is 1/4 inch (0.635 cm) from the vertical edge 31 of the skins 21. This permits the trimming of the door assembly 20 with conventional woodworking tools.
The perimeter frame 23 includes horizontal rail 33 and vertical stiles 34. Referring to Figures 2 and 9, a plurality of horizontally extending grippers 37 having sharp outer edges, are molded on the inner sides 28 of the skins 21 and 22. A rail positioning member 38 also projects inwardly from the top and bottom surfaces of the inner sides 28 of the skins 21, 22. As shown in Figures 3 and 4, the rails 33 abut the rail positioning members 38. The grippers 37 pierce the surface of the rails 33 and aid in preventing undesired relative motion between the rails 33 and the skins 21,22.
A plurality of vertically extending projections 40 are positioned inwardly from the inner side 28 of the skins 21,22. As best shown in Figures 5 and 6, the projections 40 engage the stiles 34 of the perimeter frame 23. In the present embodiment, a pair of the vertically extending projections 40 are provided or defined along each edge of the skin 21 or 22.
It has been found that a compression molded door assembly 20, as described above provides a door assembly which has the dimensional stability in various environmental conditions together with a pleasing appearance. It has been found that the exterior surface of the door assembly 20 may be stained with a wood stain or with a topcoat, suchas urethane topcoat.
While the present embodiment shown in Figure1, is directed to a nine unit "raised panel" design,simulating a wood door having a similarappearance, it is understood that various otherdesigns may be constructed in accordance with the present invention without departing from the appended claims.