Molded wood composites having non-blistering profile with uniform paintability and nesting

A molded wood composite article man-made from wood fibers or wood particles on at least an upper, molded surface of the article, and a method of manufacturing the article to include a relatively uniform density, detailed design contours and textured aesthetics on one or more molded depression-interior inclined surfaces, while preventing embrittlement, softness and blistering of the article along the depression-interior inclined surfaces. These attributes are achieved by molding one or more depressions into an initially planar layer of cellulosic material, wherein the molded depressions have one or more inclined walls that have upper surfaces, along essentially an entire inclined span, that include detailed design contours, including adjacent curved and planar portions, e.g., bead and cove.

FIELD OF THE INVENTION 
The present invention relates to a molded wood composite article, 
containing one or more molded depressions, and a method of making the 
molded wood composite article, having an inclined profile embossed or 
molded into a depression-interior portion of the article. More 
particularly, the molded wood composite article of the present invention 
is made from a combination of cellulosic material, such as cellulosic 
fibers or cellulosic particles, and a natural or synthetic binder, such as 
a phenol formaldehyde or urea formaldehyde resin, including at least about 
80% cellulosic material, and molded from a mat having at least an upper 
surface formed from refined, fibrillated cellulosic fibers, e.g., a 
fiberboard mat, such as hardboard; or made from cellulosic particles, such 
as particle board. The major surfaces of the articles are molded from a 
planar layer of cellulosic material, e.g., a fiberboard mat, made either 
by the wet process or the dry process, preferably the dry process; or made 
from a layer of cellulosic particles and a resin binder. The planar layer 
of cellulosic material is molded when the cellulosic layer contains less 
than about 10% moisture, based on the dry weight of the cellulosic layer, 
regardless of the method of making the cellulosic layer. Essentially no 
gas venting is required until the molding operation is complete and the 
mold is opened. The depression-interior inclined molded profile does not 
blister, has relatively constant paint holdout, and provides better 
nesting, one article on another, for shipping and storage without damage. 
BACKGROUND OF THE INVENTION 
Man-made boards, such as fiberboard, e.g., hardboard; chipboard; oriented 
strand board-fiberboard composites; particle board; oriented strand 
board-particle board composites; and the like, commonly are embossed on 
their intended visible major surface in the manufacture of interior 
panelling, exterior siding, and particularly in the manufacture of door 
skins that are laminated to a support structure or frame, on both major 
surfaces, for replicating multi-panel doors having surfaces that are man 
made, rather than the very expensive natural wood "6-panel" doors. 
Commonly, such articles are molded from a planar cellulosic mat to include 
one or more interior or "closed" depressions, within an interior of the 
article, such as one or more square or rectangular depressions that do not 
extend to an outer edge of the article. 
The cellulosic fibers or particles used to form the loose mat, e.g., a 2 
inch thick layer of cellulosic fibers, initially may be bone dry after the 
fibers have been dried and felted, but the cellulosic materials in such 
mats absorb moisture from the atmosphere and generally include about 2% to 
about 10% moisture when molded via hot pressing, depending upon the 
humidity in the region where such mats are stored and/or manufactured. A 
molded or embossed design in a layer of cellulosic material that leaves 
interior depressions in the molded article is difficult to provide without 
surface defects because gases formed during hot-pressing, e.g., vaporized 
moisture, cannot escape from the mold cavity via venting to an exterior 
edge of the molded article when the molded article is hot-pressed to a 
constant mold level completely surrounding the formed interior 
depressions. 
In some mold designs formed in wood composites, venting is accomplished by 
disposing a gas pervious material, e.g., a temperature-resistant, 
gas-pervious fabric, between a back half of the mold cavity and a 
non-visible side of the product being molded, to achieve controlled gas 
venting without blister formation in the molded article. Controlled gas 
venting during the hot-press molding of wood composite articles, however, 
tends to disrupt the complete consolidation and bonding of the molded 
articles along the molded edges, due to the escape of gas at the edges, 
causing excessive scrap or wasted material. Wasted material results from 
trimming the incompletely consolidated edges, containing valuable 
cellulosic material and binder, which must be trimmed away to achieve 
solid, completely consolidated, scratch resistant man-made board material 
over the entire major, exterior surface of the trimmed molded article. 
Accordingly, when such waste cannot be tolerated, a mechanical dam is 
included, surrounding the mold cavity, to eliminate essentially all gas 
venting during the hot-press molding step to avoid "punky" edges that end 
up as waste. 
A typical mechanical mold dam is a metal border extending from, and 
perpendicular to, one half of the mold or die, and extending, for example, 
0.030 inch vertically toward the other half of the mold or die, to create 
sufficient pressure on the material being molded, completely surrounding 
the mold cavity, to prevent essentially all gas escape until the mold 
cavity is opened. Gas venting, when such mechanical dams are used, occurs 
almost exclusively as a result of opening the mold cavity upon completion 
of the hot-press molding step. The sudden reduction in pressure upon mold 
cavity opening, however, sometimes causes a sudden release of water vapor 
trapped beneath the upper surface of the molded article, thereby causing a 
portion of the visible molded surface to bubble or blister--a portion of 
the molded surface delaminates from the remaining thickness because of the 
sudden escape of gas from an interior portion of the molded article. This 
blistering problem is most severe when attempting to mold detailed designs 
onto an inclined interior surface portion of closed depressions molded 
into wood composites. 
Other problems occur in attempting to form the above-described inclined 
molded portions on an interior surface of closed depressions in a molded 
wood composite article, particularly when it is commercially necessary to 
paint such inclined surfaces to provide an aesthetically pleasing outer 
surface. One type of product, in particular, that must include excellent 
embossing detail and superior aesthetic qualities to be commercially 
acceptable, is a door skin that simulates a multi-panel natural wood door 
on both major faces of a support substrate or frame member. Door skins, or 
door faces, require detailed, inclined interior molded walls having a 
plurality of relatively close contours that include varied curves and 
planar surfaces. It has been found that these interior, inclined molded 
surfaces of interior inclined molded depression walls are very difficult 
to paint uniformly due to density differences, because of various curved 
and planar adjacent contours and due to the confined locations of the 
inclined surfaces within the relatively small, molded depressions. These 
angled or inclined surfaces on wall portions molded into depressions 
formed in the interior of the product are extremely difficult to provide 
with embossed surfaces representing, for example, a wood grain pattern, 
since such embossed texture on depression-interior inclined walls have a 
tendency to cause the article to stick to the mold cavity at the embossed 
inclined wall, causing fiber to pull away from the surface of the molded 
article when it is removed from the mold cavity. 
Another problem common to the molded wood composite articles described 
above is in stacking a plurality of the molded articles for efficient 
shipping. Extant door skins, for example, when stacked one above another, 
having a depression profile as shown in the drawing identified as "Prior 
Art" have a tendency to damage, particularly in the upper decorative 
surface of the lowermost articles, due to abrasive contact on the detailed 
depression-interior inclined surfaces, particularly on the convex, 
uppermost "bead" of a "bead and cove" Colonist design, where aesthetics 
are most important, and where damage is most apparent. 
The molded wood composite articles of the present invention solve some or 
all of the above-mentioned deficiencies in prior art molded wood composite 
articles to provide a molded wood composite article that has inclined, 
decorative depression-interior molded walls having upper, decorative 
inclined surfaces of relatively uniform density; can be painted with 
uniform paint hold-out; has molded, inclined surfaces that are accessible 
for buffability, in the preferred embodiment; and wherein the molded, 
inclined depression-interior surfaces are capable of being embossed with 
excellent texture or grain detail to provide an extremely aesthetic, 
detailed texture or grain design. In the preferred embodiment, the 
inclined depression-interior walls are longer and less severely inclined 
(about 25.degree. to about 38.degree.) than prior art depression-interior 
molded wall surfaces, and include a profile in the depression-interior, 
inclined molded surfaces such as an embossed "bead and cove" design, that 
permits excellent stacking of the articles for efficient, and essentially 
damage-free shipping and storage, while stacking more articles, one upon 
another. 
SUMMARY OF THE INVENTION 
In brief, the present invention is directed to a molded wood composite 
article man-made from wood fibers or wood particles on at least an upper, 
molded surface of the article, and a method of manufacturing the article 
to include a relatively uniform density, detailed design contours and 
textured aesthetics on one or more molded depression-interior inclined 
surfaces, while preventing embrittlement, softness and blistering of the 
article along the depression-interior inclined surfaces. These attributes 
are achieved by molding one or more depressions into an initially planar 
layer of cellulosic material, wherein the molded depressions have one or 
more inclined walls that have upper surfaces, along essentially an entire 
inclined span, that include detailed design contours, including adjacent 
curved and planar portions, e.g., bead and cove. The inclined 
depression-interior molded walls, having upper surfaces that include the 
adjacent curved and planar contours, have a thickness or caliper 
measurement, measured normal to a tangent at any point along the upper 
(finished) contoured surface, that varies at most about 20% from the 
caliper so measured at any other point along the depression-interior 
contoured, inclined surface span, with the exception of the ends of the 
inclined span. Preferably, the thickness differential along the entire 
contoured, inclined surface (with the exception of the ends of the 
inclined span, where each end of the inclined surface joins a horizontal, 
as molded, portion of the article) is at most about 15%, more preferably a 
maximum thickness differential of about 10%, while providing detailed, 
adjacent curved and planar surfaces on the depression-interior inclined 
wall surface, e.g., a "bead and cove" molded pattern. 
It has been found that the mean thickness or caliper along the entire 
contoured inclined depression-interior molded walls of a wood composite 
article, molded in accordance with the present invention, should be molded 
to be about 2% to about 15% thinner, preferably about 3% to about 10% 
thinner, and more preferably about 5% to about 8% thinner, than a 
thickness of adjoining horizontal portions of the wood composite articles. 
Where the ends of the depression-interior inclined contoured walls meet 
the horizontal (as molded) surfaces, the article should be compressed or 
"pinched" to a thickness or caliper that is about 1% to about 12%, 
preferably about 2% to about 10% less than the mean thickness along the 
depression-interior inclined wall span between the two "pinched" ends of 
each inclined wall. It has been found that an article formed to include 
such an inclined wall with "pinched" ends has a relatively uniform density 
and excellent strength along the entire span of the inclined wall, 
particularly where the inclined wall ends join horizontal portions of the 
molded article, while preventing embrittlement, softness and blistering 
along the entire upper surfaces of the depression-interior inclined 
wall(s), to achieve excellent paint-holdout and uniformity, and without 
blistering along the depression-interior inclined wall surfaces, with 
essentially no gas venting required during the molding cycle. 
It is apparent to those skilled in the art that the articles described 
herein can be formed from materials other than cellulosic materials, e.g., 
polymeric or plastic articles, while advantageously including one or more 
interior, inclined walls having a contoured upper surface with adjacent 
curved and planar portions having an angle of inclination from the 
horizontal of 38.degree. or less, and a thickness along the inclined span 
that varies no more than about 20%, preferably no more than about 15%, and 
more preferably no more than about 10%. Such an article, regardless of the 
material used to form the article, will nest, one article above another, 
for storage and transport without significant surface scratching or other 
surface damage and provide for easier application of decorative surface 
details in the upper surface of depression-interior, inclined walls. 
Accordingly, one aspect of the present invention is to provide a molded, 
wood composite article, and method of manufacturing the article, that 
includes interior molded depressions having an inclined, decorative 
surface that has a relatively uniform density along the entire inclined 
surface, which is not brittle or blistered as a result of the molding 
process. 
Another aspect of the present invention is to provide a molded, wood 
composite article, and method of manufacturing the article, containing at 
least about 80% cellulosic material, that is molded from an incompletely 
consolidated planar mat or preform using heat and pressure to include a 
decorative inclined surface in a molded depression within the interior of 
the article, wherein the inclined surface does not blister, while 
permitting essentially no gas venting from the mold cavity during the hot 
press molding process. 
Still another aspect of the present invention is to provide a molded 
man-made wood composite article that includes a molded depression that 
includes adjacent curved and planar surfaces, e.g., "bead and cove" on a 
depression-internal inclined surface having an inclination of about 
25.degree. to about 45.degree., preferably about 25.degree. to about 
38.degree. from a horizontal lower surface integral with a lower end of 
the inclined wall, that nests with a molded inclined wall undersurface of 
an identical wood composite article for storage and shipping without 
damage to the inclined surfaces; and wherein the inclined surfaces have a 
uniform paint-holdout capability and are easily embossed with a texture or 
other decorative design, e.g., simulating wood grain. 
Another aspect of the present invention is to provide a decorative article 
of manufacture, that may be formed from plastic, or other non-wood 
material, that includes a depression having an interior inclined wall that 
has an angle of inclination, from a horizontal at a lowermost end of the 
inclined wall, in the range of about 25.degree. to about 38.degree., 
wherein the depression-interior inclined wall has a thickness 20% or less, 
preferably 15% or less, and more preferably 10% or less relative to a mean 
thickness of said inclined wall between upper and lower planar walls that 
are integral with upper and lower ends, respectively, of the inclined 
wall. 
The above and other aspects and advantages of the articles and methods of 
the present invention will become more apparent from the following 
detailed description of the preferred embodiments, taken in conjunction 
with the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the preferred embodiments shown in the drawings, the molded wood 
articles of the present invention are molded in the form of a multi-panel 
door, or, more preferably, as a thin door skin to be laminated or 
otherwise adhered to a core, frame or support substrate, on both major 
surfaces, to simulate a solid, natural wood door, e.g., an interior or 
exterior passage door, as shown in FIG. 1, or a cabinet door. It should be 
understood, however, that the principles of the present invention apply to 
much more than the manufacture of doors or door skins and apply to any 
molded man-made composite wood article that includes one or more 
depression-interior walls that have an inclined, contoured decorative 
surface extending within the depression and adjacent to a planar, e.g., 
horizontal surface portion of the molded article. Examples of other 
composite, molded wood articles that are capable of being manufactured in 
accordance with the principles of the present invention include decorative 
hardboard; interior and exterior siding; decorative interior wall 
panelling; structural cores; roofing material; crating structures; and the 
like. 
A surface portion of the articles of the present invention should be formed 
from cellulosic material, such as fibrillated cellulosic fibers, or 
cellulosic particles and a binder capable of adhering the cellulosic 
material together into a structurally stable article. The cellulosic 
fibers, whether in the form of refined, fibrillated fibers, or in the form 
of discrete particles, can be molded and adhered together with natural or 
synthetic binders to provide aesthetically pleasing contours and texture 
in all exterior, visible surfaces, including the depression-interior 
inclined wall surfaces. The articles of the present invention can be 
molded as a thin, e.g., 0.1 to 0.2 inch thick door skin, or the articles 
can be molded together with an underlying core material, such as an 
oriented strand board, particle board, plywood, wafer board, or a 
thermoplastic or thermosetting plastic core material by molding the face 
or skin cellulosic material together with the underlying core material. 
The following U.S. patents are hereby incorporated by reference as 
examples of various different cores, having cellulosic fibers or particles 
as a surface layer, that are suitable for molding in accordance with the 
present invention: Shaner, U.S. Pat. Nos. 4,361,612; Wentworth 4,364,984; 
Greten 3,098,781; Birmingham 2,343,740; Bryant 3,308,013; Elmendort 
2,831,793; Hunt 4,246,310; and Barnes 4,610,913 . Alternatively, a thin 
cellulosic molded surface layer can be molded separately, in accordance 
with the present invention, and later laminated to a support structure. 
Turning now to the drawings, and initially to FIG. 1, there is illustrated 
a door, generally designated by reference numeral 10, shown horizontal, as 
molded, that includes an upper door skin 11, and an identical, lower door 
skin 11A secured to opposite major surfaces of a door frame or interior 
support structure 12. The door skins 11 and 11A can be molded separately 
to impart aesthetic surface contours in the visible outer surfaces that 
correspond to contours essentially identical to contours of a mold cavity 
(not shown). The door skins 11 and 11A then can be secured, e.g., 
adhesively, to a suitable core or frame structure 12. The lower half of 
the mold cavity, if shown, would be essentially the same in general 
contour to an upper surface 13 of the door skin 11, except that the lower 
mold half would be slightly larger horizontally, in the depression 
dimensions, to allow for the thickness of the molded cellulosic material 
forming the door skin. The upper mold half (not shown) is dimensioned 
complementary to the upper surface 13 of the door skin, and includes 
raised mold portions dimensioned to correspond to the depressions shown in 
the upper surface 13 of door skin 11. 
The door skins 11 and 11A are molded with the mold cavity or die halves 
disposed in a generally horizontal disposition so that the upper major 
surface 13 will be described as horizontal--corresponding to its 
disposition during molding--and it will be recognized that the position of 
the molded article, in use, may very well be opposite, as in the case of 
door skins 11, where the molded major surface 13 normally would be 
disposed in a vertical orientation. The exemplary door skins, e.g., 11, 
shown in FIG. 1, are molded to simulate a multi-panel door surface, and 
the preferred embodiment shown in FIG. 1 contains six molded depressions 
14, 16, 18, 20, 22 and 24, surrounding six panels 26, 28, 30, 32, 34 and 
36. Further, each depression is completely surrounded by planar, e.g., 
horizontal door surface portions 38, 40, 42, 44, 46, 47, 48 and 49, lying 
in a common plane. 
In the preferred 6-panel door skins 11 and 11A shown in FIG. 1, the 
depressions 14, 16, 18, 20, 22, and 24 are rectangular in shape and the 
rectangular depressions completely surround the horizontal door panels 26, 
28, 30, 32, 34 and 36 that lie in the same horizontal plane as the 
horizontal door surface portions 38, 40, 42, 44, 46, 47, 48 and 49. 
The rectangular molded depressions 14, 16, 18, 20, 22, and 24, are molded 
to include depression-interior inclined walls having upper surfaces that, 
in accordance with the present invention, are molded to a relatively 
constant density and include contours, preferably over the full span of 
the depression-interior inclined wall surfaces, that extend downwardly and 
inwardly from a planar, e.g., horizontal surface portion (38, 40, 42, 44, 
46, 47, 48 and/or 49) of the door skin 11 to a lower end of the 
depression-interior inclined wall surface, at or near a lowermost end of 
the depression, as will be described in more detail with reference the 
depression profiles shown in FIGS. 2 and 3A. 
In accordance with one embodiment of the present invention, instead of 
molding two relatively thin, e.g., about 1/8 inch, door skins 11 and 11A 
separately and then securing the door skins on opposite major surfaces of 
a door frame or other support structure 12, the support structure 12 can 
be disposed between the two door skins 11 and 11A, in the mold cavity, to 
consolidate the upper and lower layers that form the door skins 11 and 11A 
under heat and pressure, while simultaneously bonding the door skins to 
the support structure 12, in a single molding step. In this manner, a 
separate bonding step for securing the door skins 11 and 11A to the 
support structure 12 is not needed, while forming a strong bond between 
the skins 11 and 11A and the support structure via resin binder included 
in the cellulosic layers 11 and 11A surrounding the support structure 12. 
In this embodiment, other decorative products can be made, other than door 
skins, and the support structure 12 can be a cellulosic material, e.g., an 
oriented stand board or fiberboard, or a plastic material, e.g., foamed or 
solid polymer, e.g., thermoplastic or thermosetting polymer, that will 
yield at its major surfaces to receive the molded depressions formed in 
the door skins 11 and 11A. 
Turning first to the preferred embodiment of the depression profile shown 
in FIG. 3A, depression 20, and preferably each other depression 14, 16, 
18, 22 and 24, is molded to include a depression-interior contoured, 
inclined wall 60 having a contoured upper surface 62, preferably including 
a bead or curved contour 64, and a planar or cove contour 66. The 
contoured, decorative depression-interior wall surface 62 preferably 
extends from an upper end 68 to a lower end 70 of the inclined wall 60. 
The upper end 68 of the inclined wall 60 is integral with the planar door 
surface portion 46, and the lower end 70 of the inclined wall 60 is 
integral with a planar, e.g., horizontal, lowermost wall 72 forming a 
bottom wall of the depression 20. Lowermost wall 72 joins panel 32 via 
upwardly sloped walls 61 and 63. 
The inclined depression-interior molded wall 60 having an upper surface 
that includes the adjacent curved contour 64 and planar contour 66, has a 
thickness or caliper measurement, measured normal to a tangent at any 
point along the upper (finished) contour surface 62, that varies at most 
about 20% from the caliper so measured at any other point along the 
inclined surface span between inclined ends 68 and 70, with the exception 
of the thickness or caliper measurement at the ends 68 and 70 of the 
inclined span. Preferably, the thickness differential along the entire 
contoured, inclined surface (with the exception of the ends 68 and 70 of 
the inclined span, where each end of the inclined wall 60 joins a planar 
wall, 48 and 72, respectively) is at most about 15%; more preferably a 
maximum thickness differential of about 10%; most preferably with about 
90% of the inclined wall thickness being within about 5% to about 8% in 
thickness. The upper surface 62 of the inclined wall 60 should include 
detailed, adjacent curved 64 and planar 66 surfaces, e.g., a "bead and 
cove" molded pattern. 
It has been found that the mean thickness or caliper along the entire 
inclined depression-interior molded wall 60 of the wood composite article, 
e.g., door skin 11, molded in accordance with the present invention, 
should be molded to be about 2% to about 15% thinner, preferably about 3% 
to about 10% thinner, and more preferably about 5% to about 8% thinner, 
than a thickness of the adjoining planar wall portions 48 and 72 of the 
wood composite articles. Where the ends 68 and 70 of the 
depression-interior inclined contoured walls 60 meet the horizontal (as 
molded) surfaces 48 and 72, respectively, the article 11 should be 
compressed or "pinched" to a thickness or caliper that is about 1% to 
about 12%, preferably about 2% to about 10% less than the mean thickness 
along the span of the depression-interior inclined wall 60 between the two 
"pinched" ends 68 and 70, of each inclined wall 60. An article formed to 
include such an inclined wall 60 has a relatively uniform density on its 
contoured surface 62, and excellent strength along the entire span of the 
inclined wall 60, particularly where the inclined wall ends 68 and 70 join 
planar, e.g., horizontal, portions 48 and 72, respectively, of the molded 
article. Upper surface 62 of inclined wall 60, molded as described above, 
is not brittle or soft along the entire upper surface 62 of the inclined 
wall, while providing excellent paint-holdout and uniformity, and without 
blistering along the depression-interior inclined wall surface 62, with 
essentially no gas venting required during the molding cycle. 
The depression-interior molding profile of the prior art varies widely in 
thickness of the inclined wall 80, such as the Colonist profile of FIG. 5A 
or other known molded doorfacing products. Such thickness variations 
restrict the pressing latitude for consistently producing quality molded 
articles. 
The profile of the prior art depression 20A in a prior art door skin 81, 
shown in FIG. 5A has two weaknesses that the depression profile of FIG. 3A 
eliminates. First, the FIG. 5A Colonist design does not allow efficient 
nesting of the products in stacking, handling, and shipping. Second, with 
the wide variation in density in the prior art depression-interior 
inclined wall 80, coating is uneven, and the density differences limit the 
manufacturing tolerance range, reducing yields. This is because widely 
varying properties occur in the depression-interior inclined walls, e.g., 
80, when the density varies substantially. 
A nominal 1/8 inch caliper molded product, such as that shown in FIG. 3A, 
made using a dry process fiberboard mat, containing about 1% to about 15% 
phenol formaldehyde resin and about 0% to about 4% wax size, initially 2 
inches thick, and molded under a temperature of about 275.degree. F. to 
about 550.degree. F. and a pressure of about 400 psi to about 850 psi, 
shows embrittlement and fracturing when molded to a specific gravity 
exceeding about 1.10, sometimes as low as about 1.07. On the other end of 
the spectrum, if specific gravity values are below about 0.88, inclined 
wall surface softness can lead to easily damaged surfaces and deficiencies 
in coating uniformity. The relatively uniform thickness of the inclined 
wall 60 of FIG. 3A, and the inclined wall 90 (25.degree. to 45.degree.) of 
FIG. 2, varying less than about 20%, preferably less than about 5%, more 
preferably less than about 10%, over the span of the inclined wall 60, 
solves this problem. 
The depression profile 20 of the preferred embodiment, shown in FIG. 3A, 
also provides new nesting or stacking capabilities for shipping and 
storage, without damage, never before achieved in a molded composite wood 
article having one or more depression-interior inclined surfaces, as shown 
in FIGS. 3B and 4, in comparison to the limited nesting capability of the 
prior art Colonist design shown in FIG. 5B. 
The inclined wall 60 shown in FIG. 3A is inclined at 38.degree. or less off 
the horizontal, as shown in FIG. 3A. This allows any two molded articles, 
e.g., door skins 11, to always come into the same resting position in 
relationship to each other when stacking, as shown in FIG. 3B. The 
selected 38.degree. or less, preferably about 25.degree. to about 
38.degree. draft angles, on the inclined walls 60, face each other on both 
sides of the profile pattern and generate a consistent "seat" locating, 
holding, and locking a "cavity" molded backside to a "core" molded 
faceside. The normal caliper (the dimension perpendicular) in any molded 
part of the profile of the inclined wall 60 which approaches a 38.degree. 
draft, in the most preferred embodiment, should be compressed to a 
thickness no less than about 5% but not more than about 8% thinner, 
compared to that caliper measured normal to the adjacent planar, e.g., 
horizontal, wall sections 48 and 72. This is particularly advantageous 
when the planar or horizontal surface portions of the molded product 
represents approximately 75% to 90% of the product surface area, typical 
in molded door skin designs. To achieve the full advantage of the present 
invention, over 90% of the wall thickness of inclined wall 60 (FIG. 3A) is 
within about 5% to about 10% of the thickness of wall 60 at any other 
point. 
The aesthetic appearance of the inclined, depression-interior wall 60 (FIG. 
3A) has been maintained by keeping major visual elements of shadow, depth, 
and width in close proportion to the original Colonist design of FIG. 5A. 
Density differences in the inclined wall 80 in the prior art profile (FIG. 
5A) promote surface indentation upon transport, when stacked one article 
on another, at prior art low density areas. This is often seen in the 
prior art bead location 92, where skin to skin contact (FIG. 5B) occurs 
during shipment to door manufacturers. A significant reduction in nesting 
weight per unit area on the bottom skin in a 200 piece stack is achieved 
with the inclined wall 60 in FIG. 3A. This accounts for the elimination of 
fracturing that can occur in skins located near the bottom of a pallet of 
stacked molded articles, as shown in FIG. 5B. With the depression-interior 
inclined wall thickness relationships described above, and as shown in 
FIG. 3A, the stacked surface bearing area is increased by seven times that 
of the "Colonist" bearing area shown in FIGS. 5A and 5B. In addition, the 
molded articles shown in FIGS. 3A and 3B lie flatter, resisting warpage 
and cupping which can occur in-process before door assembly lamination 
takes place. 
A stacked pallet of molded articles shown in FIG. 3A also reduces the 
volume being shipped by eliminating 41% of the void space required when 
200 "Colonist" (FIG. 5A) skins are stacked for shipment, to achieve an 
overall container volume reduction of greater than about 20% (based on 200 
"Colonist" skins measuring 35 1/4 inches versus 200 (FIG. 3A) skins 
measuring 28 inches high). The actual unit height may be slightly higher 
due to board springback or effect of substrate humidification. 
In addition to achieving better nesting (compare FIG. 3B to FIG. 5B), it 
was unexpectedly found that more uniform coating characteristics were 
achieved with the new depression-interior inclined wall profile of FIG. 3A 
resulting in better efficiencies in primer (paint) application and higher 
fidelity prestaining finishes. 
The more uniform density and lower draft angle of the inclined depression 
interior wall 60 of FIG. 3A provides unique finishing attributes which 
include reducing levels of coating to achieve full coverage and the 
ability to apply uniform stain application via automated reverse brushing 
that renders a high fidelity "furniture" type finish. 
Some of the unique features of the improved depression-interior inclined 
wall profile shown in FIG. 3A, include 
1. Uniform density improving yields out-of-press with no blistering; 
2. Uniform density reducing surface damage on bottom skins after 
unitization; 
3. Improved stacking through gap reduction between skins, achieving lower 
height shipping units; 
4. Increased surface contact area allowing more loading weight during 
shipping to be applied without experiencing product damage such as 
burnishing or scuffing; 
5. Uniform density allowing for possible paint coverage reduction; 
6. Excellent prestained coating properties; 
7. Improved woodgrain fidelity based on reduced fill in the embossing 
pattern (called ticking) resulting from the lower draft angle and reduced 
paint coverage; 
8. Improved shipping and warehousing safety through better stacking 
stability (reduces potential for tipping or falling as handled in 
inventory); 
9. Reduced packaging costs by improving skin to skin stacking stability, 
units become self supporting; and 
10. Maintaining aesthetic continuity with the Colonist design, through 
similar proportional detailing with shadow-highlights and profile depth. 
The articles, and method of manufacture, described herein are most 
advantageously formed from a substrate that includes at least a surface 
layer of cellulosic fiber and a binder, e.g., a fiberboard mat and a resin 
binder, or cellulosic wood particles and a resin binder. It will be 
appreciated by those skilled in the art, however, that similar articles 
can be formed by molding, extruding or otherwise contouring upper and 
lower major surfaces, as described herein, from thermoplastic or 
thermosetting polymers, e.g., polyethylene or polypropylene with or 
without reinforcing fibers, such as fiberglass, while incorporating the 
substantially better nesting capability, and the substantially easier 
inclined surface texturing advantage for the contoured upper surface of 
depression-interior walls when the inclined wall angle is 38.degree. or 
less, and when the inclined wall does not substantially vary in thickness, 
as described for the cellulosic articles. 
It will be understood that the present disclosure has been made only by way 
of preferred embodiments and that numerous changes in details of 
construction, combination, and arrangement of parts can be resorted to 
without departing from the spirit and scope of the invention as hereunder 
claimed.