Abstract:
A door facing blank is provided that includes a central portion, first and second side portions adjacent to and integral with opposite sides of the central portion, opposite interior and exterior major surfaces, and a design element including a molded portion and an embossed portion. The side portions include stile-receiving areas that are substantially planar. The molded portion is molded in the central portion to establish a first groove portion in the exterior surface region of the central portion and a protrusion on the interior surface region of the central portion. The embossed portion is embossed in the first side portion to establish a second groove portion in the exterior surface region of the first side portion but no protrusion on the interior surface region of the first side portion. The first and second groove portions establish a continuous groove in the exterior major surface.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a door facing blank having a first major surface with a design element formed therein, and an opposite second major surface. A method of forming a door facing blank, and a mold press for forming a door facing blank are also disclosed. 
     BACKGROUND OF THE INVENTION 
     Hollow and solid core doors typically include a perimeter frame with first and second door facings secured to opposite sides of the frame. The door facings may be formed from composites of cellulosic material and resin binder, polymers, or metal. 
     Hollow or solid core doors may be of the ‘flush’ type, that is, one that is flat or planar on both major surfaces. Alternatively, one or both door facings may include contoured portions, architectural elements or textures. For example, a door facing may be molded to include contoured portions simulating stiles, rails and panels. 
     Molded and architectural features are often desirable to consumers, and may be molded or embossed into a blank during compression. However, a different die set is typically required for each size and length door facing. For example, a plurality of die sets are typically required to form door facings of different widths, even if the molded design is similar on all of the different width door facings due to the position and configuration of the molded portions on the facing. Likewise, different die sets are typically required for different length door facings, even if the molded design configuration is similar on all facings. 
     As such, molded door facings having contoured or architectural features are relatively expensive because the capital cost is quite high due to the need for dies, presses, and the like for each specific door facing size. The flat or planar facings used for flush doors, on the other hand, are relatively inexpensive, but do not provide the aesthetic features often desired by consumers. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a door facing blank having a first major surface intended to be exteriorly disposed and an opposite second major surface intended to be interiorly disposed. First and second planar, spaced stile receiving areas are disposed on the second major surface. A central portion is intermediate the first and second stile receiving areas. A plurality of grooves are formed in the first major surface and define a design element. At least one of the grooves includes an embossed portion disposed in the first major surface opposite the first and second planar spaced stile receiving areas and a molded portion disposed in the central portion. At least one of the first and second spaced stile receiving areas are trimmable to form a door facing having a selected width. 
     The present invention also relates to a door facing blank having a first major surface intended to be exteriorly disposed and an opposite second major surface intended to be interiorly disposed. A design element is formed in the first major surface. At least three longitudinally extending spaced stile receiving areas are disposed on the second major surface. Two of the stile receiving areas define a first width, and three of the stile receiving areas define a second width greater than the first width. The door facing blank may be trimmed to form a door facing having a selected width and having a first one of the stile receiving areas adjacent a first longitudinal edge of the door facing, and a second one of the stile receiving areas adjacent a second longitudinal edge of the door facing. 
     A method of forming a door is also disclosed. A perimeter frame having first and second spaced stiles defining a width is provided. First and second door facing blanks are provided. Each of the blanks has a first major surface and an opposite second major surface, a design element formed in the first major surface, and a plurality of longitudinally extending spaced stile receiving areas disposed on the second major surface. First and second stile receiving areas are selected that are spaced by a distance corresponding to the width of the first and second spaced stiles. The first and second door facing blanks are trimmed adjacent the selected first and second stile receiving areas to form first and second door facings having selected widths. The first and second door facings are then secured to opposite sides of the perimeter frame, thereby forming a door. 
     The present invention also relates to a mold press for forming the disclosed door facing blank. The mold press includes an upper die mold and a spaced lower die mold, which form a mold cavity for molding a substrate to form the door facing blank. The upper die mold has a plurality of protrusions disposed in a first portion and embossing features disposed in a second portion. The lower die mold has a plurality of depressions aligned with and complementary to the plurality of protrusions for forming molded features in the substrate, and planar portions aligned with the embossing features for forming stile receiving areas in the substrate. The die mold forms a door facing blank having at least three longitudinally extending spaced stile receiving areas on an intended interior surface thereof, two of the stile receiving areas defining a first width, and three of the stile receiving areas defining a second width greater than the first width. The door facing blank may be trimmed to form a door facing having a selected width. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a door facing blank having a design element according to an embodiment of the present invention, showing embossed portions in hatched line; 
         FIG. 2  is a sectional view of the door facing blank of  FIG. 1  taken along line  2 - 2  and viewed in the direction of the arrows; 
         FIG. 3  is an enlarged sectional view of circled portion  3  of  FIG. 1 ; 
         FIG. 4  is an enlarged sectional view of circled portion  4  of  FIG. 1 ; 
         FIG. 5  is a fragmentary sectional view of a molded groove of a design element of the present invention; 
         FIG. 6  is a fragmentary sectional view of an embossed groove of a design element of the present invention; 
         FIG. 7  is a plan view of a door facing having a design element having molded and embossed portions, with embossed portions shown in hatched line; 
         FIG. 7A  is a plan view of the door facing of  FIG. 7  after trimming a first side portion; 
         FIG. 7B  is a plan view of the door facing of  FIG. 7  after trimming first and second side portions; 
         FIG. 8  is a plan view of a door facing blank having a design element according to another embodiment; 
         FIG. 9  is a sectional view of the door facing blank of  FIG. 8  taken along line  9 - 9  and viewed in the direction of the arrows; 
         FIG. 10  is a sectional view of a door according to the present invention; 
         FIG. 11  is a plan view of a door facing blank having a design element according to another embodiment; 
         FIG. 12  is a plan view of a door facing blank having a design element according to another embodiment; 
         FIG. 13  is a plan view of a door facing blank having a design element according to another embodiment; 
         FIG. 14  is a plan view of a door facing blank having a design element according to another embodiment; 
         FIG. 15  is a plan view of a door facing blank having a design element according to another embodiment; 
         FIG. 16  is a plan view of a door facing blank having a design element according to another embodiment; 
         FIG. 17  is a plan view of a door facing blank having a design element according to another embodiment; and 
         FIG. 18  is a sectional view of a mold press according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     As shown in  FIGS. 1 and 2 , a door facing blank  10  according to the present invention includes a first major surface  12  intended to be exteriorly disposed and an opposite second major surface  14  intended to be interiorly disposed. 
     A design element is formed in first major surface  12 . An exemplary design element according to an embodiment of the present invention is shown in  FIGS. 1 and 2 . The design element includes molded grooves  16  formed in a central portion  18  of blank  10 , as shown in  FIGS. 1-3 . Molded grooves  16  include corresponding protrusions extending outwardly from second major surface  14 . Molded grooves  16  may include an upwardly extending central bead  20  intermediate side walls  22 ,  24 . 
     The design element may also include embossed grooves  16 A formed in first and second side portions  26 ,  28  of blank  10 , as shown in  FIGS. 1 and 4 . First and second side portions  26 ,  28  are shown adjecent to and integral with opposite sides of the central portion  18 . Embossed grooves  16 A may include upwardly extending central beads  20 A intermediate side walls  22 A,  24 A. While embossed grooves  16 A extend into first major surface  12 , second major surface  14  is preferably substantially planar opposite any embossed grooves  16 A, such as in first and second side portions  26 ,  28 , as shown in  FIGS. 2 and 4 . 
     As known in the art, molding a cellulosic substrate involves re-shaping the material using heat and pressure. The cellulosic substrate is re-shaped by stretching and bending the fibers of the cellulosic material during the molding process. A geometric change in the central plane of the substrate occurs during the molding process. The central plane of a planar substrate is defined at the center of the caliper of the substrate, shown by dashed line X in  FIG. 5 . The depth d 1  of a molded portion may be greater than the total caliper C of the substrate. For example, molded grooves  16  may be molded to a depth of about 0.07 inch or more, while the total caliper of blank  10  may be between about 0.1 to 0.2 inches. Preferably, molded grooves  16  are molded to a depth of between about 0.1 inch and about 0.5 inch. Thus, the depth d 1  of molded grooves  16  may be greater than the total caliper C of blank  10 . As such, a portion of molded grooves  16  extends outwardly from the plane of second major surface  14 . 
     By contrast, embossing typically involves pressing a substrate with a textured roll or plate. This process results in a slightly contoured surface having a relatively shallow profile depth, but without a geometric change in the central plane X of the substrate, as shown in  FIG. 6 . Using conventional embossing techniques, the depth of a depressed portion that has been embossed into a cellulosic fiber substrate is typically less than ⅓ of the total caliper of the substrate prior to embossing. Thus, the central plane X of the cellulosic fiber substrate is not altered during the embossing process when forming embossed grooves  16 A. Rather, embossed grooves  16 A are simply pressed inwards toward the central plane, so that the corresponding portion of second major surface  14  opposite embossed grooves  16 A is substantially planar, as shown in  FIGS. 2 ,  4  and  6 . For example, grooves  16 A may be embossed into first major surface  12  to a depth d 2  of about 0.005 inch or more. More preferably, embossed grooves  16 A are embossed to a depth d 2  of between about 0.005 inch and about 0.07 inch. 
     Molded grooves  16  are preferably configured and positioned on blank  10  so that second major surface  14  is substantially planar on first and second side portions  26 ,  28 . In this way, stiles of a perimeter frame may be easily secured to planar portions of second major surface  14  at a selected position on first and second side portions  26 ,  28 . Preferably, first and second side portions  26 ,  28  have a width greater than the width of the stiles to be secured thereto. In this way, blank  10  may be trimmed to a selected width, while maintaining a portion of each of first and second side portions  26 ,  28  for accommodating stiles. In addition, molded grooves  16  and embossed grooves  16 A are configured so that even if first and/or second side portions  26 ,  28  are trimmed, the remaining design element on the resulting door facing is aesthetically acceptable. 
     Referring to  FIGS. 7 ,  7 A and  7 B, embossed grooves  16 A extend outwardly from and linearly with corresponding molded grooves  16 . The resulting design element includes a plurality of parallel grooves  16 ,  16 A extending angularly across the entire first major surface  12 , giving the appearance of a door formed from a plurality of slanted planks P. Because first and second side portions  26 ,  28  are embossed, they may be trimmed to achieve a door facing having a selected width, while first major surface  12  maintains the same appearance. 
     For example, blank  10  having molded grooves  16  in central portion  18  and embossed grooves  16 A in side portions  26 ,  28  may be molded to have a width w 1  corresponding to a standard commercial width w 1  of door facing F 1 , e.g. a door facing having a width of about 36 inches. With minimal or no trimming, blank  10  may be used as door facing F 1 , as shown in  FIG. 7 . First side portion  26  of blank  10  may be trimmed to form a door facing F 2  having a second width w 2 , as shown in  FIG. 7A . Both first and second side portions  26 ,  28  may be trimmed to form a door facing F 3  having a third width w 3 , as shown in  FIG. 7B . The design element on first major surface  12 , which resembles a plurality of slanted planks P, is maintained on door facings F 2  and F 3 , despite first and/or second portions  26 ,  28  having been trimmed, and even if unequal portions of first and second portions  26 ,  28  have been trimmed. 
     Blank  10  may be trimmed using any conventional cutting method to form a door facing having any one of a plurality of different widths due to the configuration and positioning of molded grooves  16  and embossed grooves  16 A, which maintain an aesthetically acceptable design element on all door facing widths. For example, predetermined portions of blank  10  may be trimmed to form a door facing having one of eleven selectable widths. Conventional methods of forming door facings having the same molded design element but different widths typically require a separate die mold for each width. Blank  10  therefore substantially reduces manufacturing costs because a plurality of different width door facings may be formed from the same blank  10 , which is formed from a single die mold. 
     It should be understood that more than three different width door facings may be formed from blank  10 , given the widths of first and second side portions  26 ,  28  are substantially greater than the stiles to be secure thereto. Preferably, a portion of each of first and second side portions  26 ,  28  remains after trimming and has a width at least equal to the width of the stile to be secured thereto, so that a substantially planar longitudinally extending surface is provided for receiving the corresponding stile. 
     Blank  10  also preferably includes a first rail receiving area  30  adjacent a first end  32  of blank  10 , and a second rail receiving area  34  adjacent a second end  36  of blank  10 , as shown in FIGS.  1  and  7 - 7 B. Rail receiving areas  30 ,  34  preferably extend horizontally across blank  10 , perpendicular to longitudinal edges  38 ,  40  thereof. As such, rail receiving areas  30 ,  34  extend through first and second side portions  26 ,  28  as well as central portion  18 . Preferably, portions of the design element formed in first major surface  12  and extending into rail receiving areas  30 ,  34  are embossed (e.g. embossed grooves  16 A), as opposed to molded (e.g. molded grooves  16 ). In this way, the corresponding second major surface  14  opposite rail receiving areas  30 ,  34  is substantially planar for accommodating the rails of a perimeter frame. 
     Blank  10  may also be configured so that the design element does not extend into rail receiving areas  30 ,  34 . For example, first major surface  12  may include upper and lower planar portions resembling rails. Further, rail receiving areas  30 ,  34  may be configured to be wider than the width of the rails to be secured thereto, so that portions of rail receiving areas  30 ,  34  may be trimmed while still maintaining a portion sufficient for accommodating the rails of the perimeter frame. In this way, blank  10  may be trimmed to form a door facing having a selected length as well a selected width. 
     It should be understood that the design element formed in blank  10  is not limited to a specific configuration and position of slanted grooves  16 ,  16 A shown in  FIGS. 1 ,  2  and  7 - 7 B. Moreover, the specific configurations of grooves  16 ,  16 A are not limited to that shown in  FIGS. 3 and 4 . Rather, various configurations of a design element are possible with the present invention. 
     For example, a blank  10 A may be formed having a design element including a plurality of grooves  16  extending parallel to longitudinal edges  38 ,  40 , as shown in  FIG. 8 . Grooves  16  may be evenly spaced to define a plurality of longitudinally extending planks P 1  having uniform widths. Planks P 1  may extend from first end  32  of blank  10 A to second end  36 . 
     The design element of blank  10 A may include all molded grooves  16 , as shown in  FIG. 9 . Because molded grooves  16  have corresponding protrusions extending outwardly from second major surface  14 , molded grooves  16  are preferably spaced from one another to form stile receiving areas  42  disposed on second major surface  14  at predetermined positions between the protrusions. For example, blank  10 A may include eleven stile receiving areas  42 . Blank  10 A is configured so that stile receiving areas  42  adjacent longitudinal edges  38 ,  40  accommodate first and second stiles  44 ,  46  of a perimeter frame, as shown in  FIGS. 9 and 10 . Stile receiving areas  42  are preferably substantially planar. 
     Similar to blank  10 , the entire width of blank  10 A defines a door facing F 4  having a width (e.g. first width w 1 ) which includes all molded grooves  16 , as shown in  FIGS. 8-10 . Molded grooves  16  are spaced and configured in such a way so that blank  10 A may be trimmed to any one of a plurality of door facing sizes. Specified portions of blank  10 A are removed so that second major surface  14  can still accommodate stiles  44 ,  46  after trimming. The rails of the perimeter frame may be notched to accommodate molded grooves  16 . Thus, a plurality of different door facings may be formed from a single blank  10 A, and thus from a single die mold. 
     It should be understood that the specific widths of planks P 1  (or P) and spacing of grooves  16  may vary as desired. For example, planks P 1  (or P) may have substantially uniform widths of at least about 3 inches, and grooves  16  may be offset from a longitudinal center plane, as shown by dashed line Y in  FIG. 8 . Such a configuration and position of grooves  16  allows blank  10 A to be trimmed to form a door facing having any one of a plurality of widths (e.g. standard commercial widths of 12 inches, 18 inches, 20 inches, 24 inches, 26 inches, 28 inches, 30 inches, 32 inches, 34 inches, or 36 inches; or standard commercial metric doors widths as known in the art). Thus, blank  10 A may be used to form 10 or more different door facings having different widths. 
     Each plank P 1  preferably has a width at least equal to the width of stile  44  (or  46 ), given the width of planks P 1  define the width of stile receiving areas  42 , as shown in  FIGS. 9 and 10 . In addition, the widths of planks P 1  need not be uniform. For example, a blank  10 B having a design element including a plurality of molded grooves  16  (and/or embossed grooves  16 A) may be provided wherein the widths of planks P 2  vary, as shown in  FIG. 11 . 
     Design elements may be provided wherein molded grooves  16  (and/or embossed grooves  16 A) do not extend across the entire first major surface  12  from first end  32  to second end  36 , or from longitudinal edge  38  to longitudinal edge  40 . For example, a blank  10 C having a design element including a first rail portion  48  adjacent first end  32  and a second rail portion  50  adjacent second end  36 , as shown in  FIG. 12 . First and second rail portions  48 ,  50  are preferably substantially planar. As such, corresponding rail receiving areas  30 ,  34  are provided on second major surface  14 , as described above, which are likewise planar and accommodate rails of the perimeter frame. First and second rail portions  48 ,  50  are preferably defined by embossed grooves  16 A, so that a planar surface extends the entire length of the blank for accommodating stiles of the perimeter frame. 
     Blanks  10 D,  10 E and  10 F having other exemplary design elements including linearly extending, molded grooves  16  and/or embossed grooves  16 A are shown in  FIGS. 13 ,  14  and  15 . As described above, the design element may include both molded and embossed features. Design elements including features primarily extending horizontally, such as the design element of blank  10 F shown in  FIG. 15 , preferably include embossed grooves  16 A in first and second side portions  26 ,  28 , and molded grooves  16  in central portion  18 , as described above. 
     The design element formed in the blank of the present invention is not limited to parallel, linearly extending grooves  16 ,  16 A. For example, a blank  10 G having an organic design element may be formed in first major surface  12 , as shown in  FIG. 16 . Any organic design element, such as a design pattern having the characteristics of a living organism(s) such as a plant or flower, may be formed in first major surface  12 . Alternatively, a blank  10 H having a design element including a geometric configuration may be formed in first major surface  12 , as shown in  FIG. 17 . Any geometric design element, such as a design pattern characterized by straight lines, triangles, circles, squares, or similar regular forms, may be formed in first major surface  12 . 
     It should be understood that relatively complex design elements may also be provided, such as a plurality of concentric circles or textured surface. It may be desirable to form such complex design elements by embossing only, given it may be more difficult to mold such features compared to embossing. However, all design elements provide that the blank may be easily trimmed to any desired length and width while maintaining a commercially acceptable design element on first major surface  12 . 
     Other molded and/or embossed design elements not specifically shown in the figures are also within the scope of the disclosed invention. Regardless of the specific design element provided, predetermined portions of the blank may be trimmed along one or both longitudinal edges  38 ,  40  to achieve the desired facing width, while providing areas on second major surface  14  for accommodating stiles and/or rails (e.g. planar first and second side portions  26 ,  28 ; stile receiving areas  42 ; and/or rail receiving areas  30 ,  34 ). 
     The cost of manufacturing a plurality of door facings having different widths but similar design elements is substantially reduced given one blank (e.g. blanks  10 - 10 H) may be used to form a door facing having a selected width and length. Moreover, only one die mold is required to form the blank, thereby minimizing the number of die molds required. Referring to  FIGS. 1 ,  2  and  18 , blank  10  may be formed from a mat M of cellulosic fiber material and resin binder, as known in the art. Mat M is disposed within a mold press  100  having an upper die mold  102  and a lower die mold  104 , and compressed therebetween using heat and pressure. Upper die mold  102  may include outwardly extending protrusions  106  for forming molded portions  16  in the resulting blank  10 , and embossing portions  108  for forming embossed portions  16 A. Lower die mold  104  includes depressions  110  corresponding to protrusions  106 . However, areas corresponding to embossing portions  108  are planar, thereby forming planar areas on second major surface  14  of the resulting blank  10  (e.g. first and second side portions  26 ,  28 ). 
     Thus, one mold press  100  having the desired design element may be used to form a plurality of door facings having different widths, thereby substantially reducing manufacturing costs. While die mold  100  is described as molding a cellulosic mat M, it should be understood that a die mold for post-molding a wood composite panel may also be provided, or for molding other materials such as a polymer composite (e.g. sheet molding compound or fiberglass reinforced composites) or metal (e.g. steel or aluminum). 
     The present invention is also directed to a method of forming a door. A perimeter frame having first and second spaced stiles  44 ,  46  is provided. First and second door facing blanks  10  (or blanks  10 A-H) are provided having a design element, as described above, and a plurality of stile receiving areas  42 . First and second stile receiving areas  42  are selected, which are spaced by a predetermined distance. Blanks  10  are then trimmed adjacent the selected stile receiving areas  42 , thereby forming door facings having widths that will correspond to the width of the perimeter frame. The door facings may then be secured to opposite sides of the perimeter frame, as shown in  FIG. 10 . 
     While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications. This application is intended to cover any such modifications, variations, or adaptations of the invention provided they come within the scope of the following claims or their equivalents.