The present invention related to wood door constructions and methods.
Solid wood doors are known and generally have an aesthetically pleasing appearance. Alternatives to solid wood doors were developed to reduce cost. Improvements in door constructions are desired.
The present invention relates to a construction panel including at least first, second, and third oriented stranded board (OSB) materials in sheet form which are glued together in a back to back arrangement. In one embodiment, the construction panel can be used as a wood door core. A wood veneer covering or other covering can be placed over the core as desired. The door construction may include rails along the top and the bottom of the core, and stiles along the sides of the core.
The present invention also relates to a method of assembling a construction panel wherein at least three sheets of oriented stranded board (OSB) material are glued together in a back to back arrangement. In one preferred method, one or both of the two outermost faces of the construction panel are sanded or otherwise processed to smooth out imperfections on the outermost faces.
A further method in accordance with the present invention relates to manufacturing a door by providing a door core construction including at least three layers of oriented stranded board (OSB) material in sheet form which are glued together, and then adding stiles and rails to the core. The method further includes adding a veneer wood covering or other covering to the core. The outermost faces of the core including the stiles and rails can be sanded or otherwise smoothed out before the covering is added. Hardware can be added to the door from the top, sides, or front or rear faces.
Oriented stranded board (OSB) materials in sheet form include elongated wood chips throughout the sheet glued together to form the sheet. Such sheets are used in the construction and manufacturing industries. The sheets come in various sizes, such as 4×8 feet. The wood chips in the OSB sheets are typically oriented in an organized manner. OSB sheets are typically less expensive than solid wood. OSB sheets are also less expensive than plywood, which is made up of layers of thin sheets of wood glued together. OSB sheets are available in a variety of thicknesses.
OSB sheets, while having a uniform appearance in general from a front face to a back face through the sheet, actually have stronger outer layers relative to the middle layer. In some instances, the outer layers of the OSB sheets include smaller wood chips and less voids than the middle layer.
One implementation of the invention is to utilize separately made sheets of OSB material, and select desired thicknesses to be adhesively joined to create a desired door core thickness, taking into account that outer portions of the core are removed by thinning the door core during the door construction process. The resulting door core includes multiple original outer layers or portions of the original sheets of OSB material. In one preferred implementation, four original outer portions are included in the final door construction.
Referring now to
Door 10 also includes top and bottom rails 40. Only top rail 40 is shown. Door 10 includes side stiles 50. Both rails 40 and stiles 50 are affixed to core 30. Rails 40 and stiles 50 can be made from conventional materials, such as solid wood (e.g. hardwood such as oak). Alternatively, rails 40 and stiles 50 can be made using multiple layers of OSB panels or sheets. A veneer covering 60 of solid wood is provided to give door 10 a more aesthetically pleasing appearance. Veneer covering 60 can be made from other materials and can be attached with adhesive.
Referring now to
With respect to each separate sheet 70, 80, 90, original outer portions or layers 110 are identified relative to a middle portion or layer 112. As noted above, outer portions 110 of each sheet of OSB material are typically stronger than middle portions 112 in its form as manufactured. Note that the dashed lines are approximate and that there is often not a clear delineation between the stronger outer portions 110 and the weaker middle portions 112.
In some door constructions, the outer faces 120, 122 of core 30 are sanded or otherwise removed before veneer wood covering 60 is applied. Compare
In one example, core 30 is made as follows: first and third sheets of OSB material 70, 90 at 7/16 inches thick; second sheet of OSB material 80 at 23/32 inches thick; adhesives 100, 102 are the same PVA material. A press can be used to hold core 30 together during curing of the adhesive. Core 30 is then sanded to a thickness of 1 and ½ inches. Door 10 then has up to four original outer portions 110 of OSB material for strength and/or holding mounting hardware (screws).
Door 10 with core 30 is designed to meet various industry standards for Window & Door Manufacturers Association (WDMA) including: Screwholding WDMA TM-10, 1990 of 330 pounds horizontal door edge and 550 pounds vertical door edge; and Cycle Slam WDMA TM-8, 1990 of 1,000,000 cycles, for Extra Heavy Duty performance.
Referring now to
In some embodiments, core 30 and strip 30′ can include more than three layers of OSB material, such as four or more.