Note: Descriptions are shown in the official language in which they were submitted.
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COMPRESSION MOLDED, INSERTED THERMOSET
DOOR LIGIiT FRAMES, PLANT-ON MOLDINGS,
AND DECORATIVE PANELS
TECHNICAL FIELD
The present invention is directed to the manufacture of insertable or
adherable, strippable door light frames, plant-on moldings, and decorative
panels,
which are durable, match the stain color applied to the exterior door or
sidelite on
which they are mounted, and avoid significant degradation when the stain and
topcoat are stripped with aggressive finish strippers such as those based on
methylene
chloride.
BACKGROUND ART
Door lights are windows mounted in an exterior door or sidelite.
Door light assemblies or cassettes generally consist of inner and outer molded
peripheral frame members, which are the door light frames, both secured
together
with fasteners surrounding the central panels between the frames of glass,
plastic or
other material. The door light frames clamp from opposite sides to the door or
sidelite, in particular to allow for differences in the thickness of the doors
to which
they are to be applied. Decorative panels are generally made analogous to door
light
frame assemblies with a solid panel substituted for the transparent or
translucent
panels such as may be made from glass. The panel may be integral to the
peripheral
frame or inserted as desired, as predetermined by the process used in the
frame and
central panel manufacture. Plant-on moldings are singular peripheral frame
members
secured to the exterior door or sidelite on which they are mounted. Fastening
may
involve screws or barbed mounting members integral to the frame member.
Door light frames, plant-on moldings, and decorative panel designs
are known in prior art as illustrated by McConnell United States Patents
4,523,408
and 4,839,989, and Jouanny French Patent 2328095. In general, door light
frames,
plant onTmoldings, and decorative panels are typically manufactured from
stamped,
press braked, andlor rollformed steel; injection molded polystyrene, polyvinyl
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chloride (PVC) or fiberglass reinforced thermoplastic; cast polyurethane foam;
as
well as extruded and assembled thermoplastic, such as PVC, styrene-maleic-
anhydride/PVC coextruded laminates (SMA/PVC); or shaped wood. The perfor-
mance and aesthetic properties of the door light frames, plant-on moldings,
and
decorative panels relative to the door on which they are mounted are generally
determined by the forming processes and the materials used.
The doors and sidelites into which the door light frames, plant-on
moldings, and decorative panels are inserted are typically made of wood,
steel,
polyvinyl chloride, fiberglass reinforced sheet molding compound, and
thermoset
phenolics filled with wood fibers. It is notable that in the door and sidelite
industry,
doorlights from one manufacturer may be used in doors and sidelites
manufactured
by a second manufacturer
Staining of exterior doors and sidelites to mimic the color and grain
of wood is desired by many customers. Discerning customers object when the
staining of the door light frames, plant-on moldings, and decorative panels do
not
match the darkness, color, or graining texture of the door or sidelite into
which the
door light cassette is assembled. Numerous problems are common in staining
doors,
door light frames, plant-on moldings, and decorative panels.
Steel doors and sidelites, door light frames, plant-on moldings, and
decorative panels are generally not acceptable as imitations of stained wood
doors
and sidelites, even when textured to simulate wood. Such doors are usually
painted,
not stained. PVC doors and sidelites, door light frames, plant-on moldings,
and
decorative panels typically are also not stained; dark colors allow greater
heating of
the surface of the door during direct sun exposure. It is typical that PVC
will warp
and twist as the skin temperature increases above approximately 85 °C.
For refer-
ence, the temperature in the air space between a glass storm door and a door
may
reach 95 °C at least once a year in most regions of the U.S. In
addition, stain coats
on thermoplastics may experience witness lines caused by significant expansion
and
contraction due to the relatively high coefficient of linear thermal expansion
of PVC.
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Recent modifications to thermoplastics, such as additions of fiberglass
reinforcements, and microcellular foaming, whether of PVC or other
thermoplastics,
e.g., acrylonitrile-butadiene-styrene (ABS), reduce linear thermal expansion
and
improve heat resistance, thereby mitigating, but not eliminating, the
distortion and
witnessing issues. However, the resultant products when stained still do not
match
compression molded thermoset doors. Reinforced PVC and microcellular foamed
thermoplastic doors are not commercially available.
Stainable steel doors and sidelites are known in the prior art. These
products consist of steel door and sidelite assemblies coated with a thin
plastisol
coating of PVC. The surface of the PVC may be textured to imitate wood grain.
No door light frames, plant-on moldings, or decorative panels currently are
manufac-
tured to duplicate this door or sidelite surface. But, even if they were,
stripping of
the topcoat and stain from these PVC surfaces with the aggressive solvents
which are
typically used, damages the plastisol PVC surface irreparably.
Wood doors and sidelites, door light frames, plant-on moldings, and
decorative panels have been aesthetically acceptable, especially when veneers
are
used. However, such products are notoriously difficult to maintain due to
expansion
and contraction with humidity as well as degradation of the wood substrate by
ultraviolet light due to exposure to the sun. Color and texture variation of
the wood
due to species differences, frequent use of joining random wood cuttings, as
well as
natural variation within species and within individual boards makes matching
exceptionally difficult. Stripping the topcoat and stain from these doors is a
very
difficult, and frequently unsuccessful process that may include substantial
use of
bleaching compounds. In addition, decorative panels are often made integral to
the
door or sidelite assembly and therefore the entire door or sidelite assembly
must be
replaced when a single panel is damaged.
Doors and sidelite assemblies have been made by compression
molding of sheet molding compound or phenolic-based resol resins with wood
fiber.
These doors are intended for staining and additionally feature texture to
simulate
wood graining. Examples include door assemblies shown in U.S. Patent No.
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4,550,540 and U.S. provisional application Serial No. 60/010,838. Examples of
materials needed to simulate wood graining are shown in U.S. patent 5,537,789.
All
these are incorporated herein by reference.
Compression molded door and sidelite assemblies with integrally
molded thermoset decorative panels and with integrally molded thermoset door
light
frames such as those disclosed in U.S. Patent No. 4,720,951, allow production
of
products with improved aesthetics, durability, and matching stainability. In
addition,
topcoat and stain are more easily removed from these products by stripping.
However, when the integrally molded glass unit fails the entire door or
sidelite
assembly must be replaced at considerable expense. The warehousing cost andlor
lead time for product delivery necessary to maintain an equivalent number of
stocking units, as opposed to using insertable door light frames, plant-on
moldings,
and decorative panels is increased unacceptably.
Moreover, manufacturing and shipping of door or sidelite assemblies
with integrally molded decorative panels is very difficult. The datum surface
area
of the doorlight or sidelite face is small, requiring extra strength in the
thermoset
material to prevent crushing, or requiring a formed tray to protect the
upraised
surfaces. Both these alternatives add substantial manufacturing costs. For
these
reasons, door light frames, plant-on moldings, and decorative panels that may
be
inserted later into the door or sidelite have been accepted by the market as
the
preferred approach to lower manufacturing and inventory costs as well as ease
of
handling.
Molded door light frames, plant-on moldings, and decorative panels
providing stainable peripheral frames have been prepared using cast
polyurethane
foam with densities of 190-400 kg/m3. However, to accept stain, a primer
coating
containing relatively high percentages by weight of pigments and inorganic
solids
must first be applied. Door assemblies using exterior surfaces of cast solid
polyurethane or polyurethane laminates have not been economical, and have not
met
with commercial success. Smaller sidelite panel assemblies of solid cast
polyurethane into which door light frames and decorative panels have been
inserted
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have been commercially introduced and later withdrawn, replaced by compression
molded thermoplastic sidelite assemblies.
Cast polyurethane foam inserted frames, plant-on moldings, and
decorative panels with primer most closely approximate the stainability of
compression molded doors. The match is still generally not acceptable to
discerning
customers, however. At polyurethane foam densities that are econornicaily
viable
(approximately 190-400 kglm3), these frames, plant-on moldings, and decorative
panels are still very fragile during shipping and installation. They are
susceptible to
thread stripping by screws used to assemble them, and subject to easy abrasion
of the
primer coating. Unless the polyurethanes are prepared from aliphatic
disocyanates,
door lights and other products which become exposed to the sun due to wear or
weathering of stain and top coat may be rapidly degraded.
Door light frames, plant-on moldings, and decorative panels with a
density of range of approximately 300-1200 kg/m3 that are durable and
stainable
have been prepared using low pressure injection molding of reinforced
thermoplastics. The resulting products are more porous than the skins
manufactured
by compression molding. As a consequence, applying equivalent amounts of stain
to the door or sidelite skin and door light frame surfaces results in a darker
stain on
the door light frame. Discerning customers fmd that difference unacceptable.
Significant effort and skill must be expended to reduce the porosity effects
during the
staining of frames, plant-on moldings, and decorative panels produced by low
pressure injection molding. These include soaking the decorative panels' or
door
light frames' aesthetic surfaces with a volatile diluent such as paint
thinner, priming
the aesthetic surfaces of the door light frames or decorative panels with a
sealant, or
diluting the stain with a compatible solvent. All techniques require increased
elapsed
time to finish the door skin and door light frame assembly. Therefore, there
is a
generally unacceptable economic penalty to the user. In addition, exposure in
excess
of 20 minutes to aggressive paint strippers, such as methylene chloride-based
strippers, softens aesthetic surface material and removes primers.
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Therefore, there is a need for materials and processes that produce
durable, insertable door light frames, plant-on moldings, and decorative
panels that
can be economically stained to match the color and aesthetics of the
compression
molded thermoset door skins upon which they are installed. The materials and
processes must produce door light frames, plant-on moldings, and decorative
panels
that allow easy stripping of topcoat and stain without damage to the aesthetic
surface,
and which are capable of withstanding use temperatures without distortion. It
would
be further desirable to produce doorlight frames, plant-on moldings, and
decorative
panels which can be applied to door frames without requiring complicated
fastening
means, and in panels, without requiring cutting holes in the door.
DISCLOSURE OF INVENTION
The present invention is directed to insertable, strippable door light
frames, plant-on moldings, and decorative panels manufactured by compression
molding a curable material into a thermoset, non-foam resin material. These
door
lights, plant-on moldings, and decorative panels are separately manufactured
from
the door skin or slab, and may be termed herein "non-integral door elements."
The
curable material is composed of organic resins that are pre-polymerized or
which
further polymerize upon molding, reinforcement fibers, inorganic or organic
fillers,
and such additives typically used to aid molding or add properties such as
fire
retardancy or fungal degradation resistance, which cure during or after the
molding
process into a thermoset, solvent-resistant material.
The door light frames, plant-on moldings, and decorative panels have
an exterior aesthetic surface and an interior surface. The exterior surface
may
include textured patterns analogous to the compression molded thermoset door
skin
which it is desired to match, these patterns generally consisting of ievel
portions or
depressions predetermined by the texture of the molding tool texture These
depressions are generated in tool surfaces by etching or other means to
produce a
pattern simulating wood grain in order to enhance the aesthetic appearance
likeness
to wood grain as well as to aid in mechanical trapping of pigment during the
staining
process.
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It is the primary object of the present invention to provide durable,
insertable door light frames, plant-on moldings, and decorative panels that
can be
economically stained to match the color and aesthetics of the compression
molded
thermoset door skins upon which they are installed.
Other objects and advantages of the invention shall become apparent
upon review of description of the preferred embodiments and accompanying
drawings. _
BRIEF DESCRIPTION OF DRAWINGS
FIGURE 1 is a frontal elevation view of a door lite frame as a
component of a door light assembly;
FIGURE 2 is a cross-sectional view taken along axis 2-2 of Figure 1;
FIGURE 3 is a frontal elevation view of a plant-on molding;
FIGURE 4 is a cross-sectional view taken along axis 4-4 of Figure 3
showing the plant-on molding;
FIGURE 5 is a frontal elevation view of a decorative panel; and
FIGURE 6 is a cross-sectional view taken along axis 6-6 of Figure 5
showing the two decorative panels as components in a decorative panel
assembly.
BEST MODE FOR CARRYING OUT THE INVENTION
Example 1
The present invention will now be described in detail with reference
being made to the accompanying drawings. In this example, the door light frame
1
is composed of molding compound taken from the following families of
compounds:
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bulk (or dough) molding compound; kneading molding compound; an injection
molding compound known as AMC; thick molding compound; and sheet molding
compound, both chemically thickened and physically thickened varieties; more
preferably the epoxy, vinyl ester, phenolic, dicylcopentadiene-based and
polyester
bulk and sheet molding compounds. and most preferably unsaturated polyester
sheet
molding compound. This is a material comprised of 5 to 72 weight percent
fibrous
glass reinforcement, preferably 17-25 weight percent, and most preferably 19-
22
weight percent of 2-3 mm long, chopped strand S-glass fibrous glass; inert
fillers;
mold releases; and other additives in the molding resin. Other reinforcements
may
be substituted for fibrous glass such as wood and Iignocellulose fibers,
aramide
fibers, carbon fibers. or mineral reinforcements such as mica. Fillers may
include
wood, sawdust and excelsior as well as inorganic fillers such as calcium
carbonate.
Unsaturated polyester polymers blended with vinyl monomers such as styrene are
molding resins that may be cured under heat and pressure to form thermoset
compression molded door light frames. Suitable molding compounds are disclosed
in U.S. Patent No. 3,772,241 to Kroekel and U.S. Patent No. 3,883,612 to Pratt
et
al., which are herein incorporated by reference. Curable materials which
produce
foam materials are not suitable in the present invention.
The preferred sheet molding compositions are prepared by blending
a resin portion with an additive portion, the additive portion containing
conventional
SMC additives such as thickeners, fillers, pigments, etc., and the resin
portion
containing curable resin, catalyst, and other components. The relative amounts
of
resin portion and additive portion may be varied to suit the particular
application, but
is normally about 18:1 by weight.
The resin portion preferably contains a 60:40 ratio of an alkyd
modified propylene glycol maleate resin thinned with styrene, and high impact
polystyrene thinned with styrene. Both resins are commercially available, for
example from Cook Composites and Polymer, Kansas City, Missouri. The resin
portion also contains, relative to 100 parts of the foregoing resins, 4.0
parts
polyvinylacetate; 1.56 parts t-butylperoxybenzoate catalyst; 1.56 parts
calcium
stearate; and 2.08 parts microfine polyethylene, available as FN 510 from
Quantum
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Chemical, Cincinnati, Ohio; 0.31 parts PEP100, an organocobalt compound on
calcium carbonate support available from Air Products, Allentown,
Pennsylvania;
and 197.60 parts calcium carbonate filler available from Huber, Norcross,
Georgia,
as Huber W-4 calcium carbonate. To the total mixture, chopped S-glass, 1"
nominal
length, is added in an amount of approximately 22 weight percent.
This door light frame has a thickness between 1.25 mm and 4 mm,
preferably 1.25-2.5 mm in the wall and 2.0-2.6 mm in the screw bosses, if
present.
Density of the product ranges between approximately 1500-2350 kglm3, as
determined primarily by the quantity of material charged in the press and the
press
pressure. The compression pressure may vary from 1000 to 15,000 kPa,
preferably
2,500 to 5,100 Kpa at temperatures of 150°C to 180°C. The
exterior, aesthetic
surface of the door light frame is essentially devoid of reinforcement fibers
for a
predetermined depth of 0.10 mm. This resin rich surface aids in accepting the
stain.
A door light frame without texture may have fibers effectively at the surface,
and
requires a decorating surface applied either in situ during molding or during
a
secondary decorating operation to make an aesthetically acceptable door light
frame
so that the fibers do not witness through the stain.
Referring to Figures 1 and 2, the door light frame has an exterior
aesthetic surface 4 and an interior surface 10. In a door light assembly, a
pair of
opposed compression molded door light frames surround a central panel
comprised
of one or a plurality of the following: glass sheets 3, decorative cut glass
8, Gaming
7, and sealant 6. In addition, not shown for sake of clarity are well known
items
such as high temperature plastic inserts, spacers, desiccant, and coatings and
films
designed to lower heat transmission. The interior surface of the exterior door
light
frame may have an adhesive, water-impervious sealant 5 attached between the
frame
and the exterior surface of the central panel.
Essentially the same material may be used in forming compression
molded door skins. A compression molded door or sidelite skin assembly is
prepared
with a hole to receive the insertable door light assembly. The interior
surface of the
exterior door light frame of the assembly adjacent to the door or sidelite
skin surface
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may have a water-impervious sealant 9 attached between the frame and the
exterior
surface of the compression molded door assembly. The door light assembly is
fastened to the door or sidelite assembly by any of several fastening methods
including the following: press fit barbs, interlocking toothed grips, and most
typically
S screws. In this example, the screws 2 are applied from the outermost side of
the
interior door light frame into screw bosses integrally molded in the door
light frame.
Figures 3 and 4 illustrate a plant-on moiding consisting of frame 17
and snap fasteners 18.
Example 2
In this example, the decorative panel 20 (Figures 5, 6) is composed
primarily of phenolic-formaldehyde-based resin systems and wood fiber of less
than
19 pm maximum cross-section and greater than 1.25 mm minimum length,
preferably
3 mm to 6 mm. The materials that may be used in this example in the weather
exposed faces are given in PCT Patent Application Serial No. PCT/US97/14290
and
U.S. Application Serial No. 08/791,023, incorporated herein by reference. The
phenol-formaldehyde resin system may be selected from the resin families
including
phenol and formaldehyde resols; phenol-formaldehyde-melamine resols; phenol-
formaldehyde resols with separate melamine resin coating; phenol-formaldehyde
novolacs; or phenol-formaldehyde novolacs with either silane, siloxane,
polysiloxane,
or high molecular weight polyurethane coatings; preferably the resols with
melamine
coatings or the novolacs with siloxane coatings; most preferably the novolacs
with
a plurality of pre-press siloxane coatings including intimately mixed siloxane
coatings
for moisture vapor transmission control and separate water-based siloxane
coatings
for water repulsion. A decorative panel peripheral frame exposed only to
interior
conditions 12 may employ a urea-formaldehyde, melamine . fortified urea-
formaldehyde, or a melamine-urea resin. The interior areas 14 and 16 of the
panel
are composed of the same materials as exterior and interior peripheries 12 and
15,
respectively. The panel is attached via screws 13. Sealing gasket I7 seals
around
the exterior of the panel.
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In this embodiment for the exterior decorative panel 15, it is preferable
to use phenol-formaldehyde novolacs applied to the lignocellulosic fiber
material,
most preferably wood fiber, under steam pressure of 350-2370 Kpa, more
preferably
920-1750 Kpa, and most preferably 1400-1700 Kpa, in a single-disk or a double-
disk
refiner. Green hardwood wood chips are a preferred source of lignocellulose;
however, dried wood, urban wood waste such as pallets, and agricultural
lignocellulosic materials may be used. The resin system from which to
manufacture
the interior decorative panels is not as sensitive to weatherability as the
exterior
aesthetic surfaces. The base color of the material is predetermined by the
density of
the molded product, the temperature to which the fiber was exposed, and the
duration
of that exposure. The density is predetermined by the quantity of material
charged
in the press and the compressing pressure required. The temperature is
predetermined by the steam pressure employed. In this embodiment, the
preferred
densities range from 1.02 - 2.08 kg/cm3, most preferably 1.33 - 1.66 kglcm3.
The
compression pressure may vary from 1000 to 15,000 Kpa, preferably 2,500 to
5,100
Kpa.
For exterior weatherability, the resin should constitute 4-24 weight
percent of the oven dried basis weight of the total material, preferably 10-15
weight
percent. Fiber and fillers should constitute 70-90 weight percent, with the
balance
of the formulation comprised of additions for processing aids and other
properties.
For decorative panels used on the interior side of the assembly, the resin
content can
range from 1-24 weight percent of the oven dried basis weight of the total
material,
preferably 4-8 weight percent.
Referring again to Figures 5 and 6, the decorative panel walls 16 and
14 range from 1.75 mm to 22.5 mm thickness. In the present embodiment, the
wall
thickness is nominally 3 mm while screw boss walls 21, if used, are nominally
5
mm. It is preferred to match the decorative panels with the door skins in
terms of
resin system and density.
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Ea~amPle 3
To achieve the light colored stains preferred by some customers, it
may be necessary to use a light colored decorative surface, such as paint
primer, on
the darker colored decorative panels. These darker panels may be created by
the
methods and materials outlined in Example 2 where the density range is 1.02 -
2.08
kg/cm3, most preferably 1.66-2.08 kg/cm3, and steam pressure of 350-2370 Kpa
system, more preferably 1700-2300 Kpa, most preferably 1800-2200 Kpa in a
single-
disk or a double-disk refiner. The phenolic novolac resin content can range
from 1-
24 weight percent with 10-15 weight percent preferred for panels exposed to
weather
of the exterior of the house and 4-8 weight percent preferred for panels
exposed to
interior conditions.
A decorative surface may be created using films, resin-impregnated
webs, veneers, laminates or paint hold-out primers. Preferred are paint
holdout
primers that may be developed from relatively high molecular weight
polyurethane
polymers, preferably thermoplastic urethane coatings in excess of
approximately
50,000 weight-averaged molecular weight; polysaccharide resins with number-
averaged molecular weight of 100,000-300,000, most preferably 100,000 to
200,000;
acrylic-urethane hybrid polymers; styrene-acrylic polymeric resins; vinylidene
chloride coatings; ethylene-vinyl chloride coatings, preferably formulated
from an
emulsion of 20-40 weight percent of 43 % solids alkylalkoxysiloxane; such as
Wacker~" 43A, 0.1-5 weight percent of 50% solids siloxane polymer such as
Sealer
Science' Siloxane Plus' or blacker 1306; 30-50 weight percent 43 % solids
acrylic
resin, such as BF Goodrich' CarbosetTM, and 0.1-10 weight percent of a resin
with
lower glass transition temperature than the siloxane and acrylic resins such
as
ethylene vinyl chloride resin with glass transition temperature between 11 and
35 °C,
such as Air Products' Airflex'~ 4514, as well as additional solvents,
adjuvants,
fungicide, mildewcide, fillers and extenders that may be added up to 49.8
weight
percent; waxes; as well as combinations thereof.
In this preferred embodiment, polysaccharide resins with number-
average molecular weights of 100,000-300,000, most preferably 100,000 to
200,000
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are used with styrene-acrylic polymeric resins; vinylidene chloride coatings;
ethylene-
vinyl chloride coatings, preferably formulated from an emulsion of 20-40
weight
percent of 43 % solids alkylalkoxysiloxane; such as Wacker'~ 43A, 0.1-5 weight
percent of 50% solids siloxane polymer; such as Sealer Science' Siloxane Plus'
or
Wacker 1306; 30-50 weight percent 43 % solids acrylic resin, such as BF
Goodrich'
Carboset~"; and 0.1-10 weight percent of a resin with lower glass transition
tempera-
ture than the siloxane and acrylic resins such as ethylene vinyl chloride
resin with
glass transition temperature between 11 and 35°C, for example Air
Products"
Airflex'~ 4514, as well as additional solvents, adjuvants, fungicide,
mildewcide,
fillers and extenders that may be added up to 49.8 weight percent; waxes; as
well as
combinations thereof.
In this preferred embodiment, polysaccharide resins with number-
averaged molecular weight of 100,000-300,000, most preferably 100,000 to
200,000
are used with styrene-acrylic polymeric resins. This primer enhances the
aesthetic
benefits by permitting relatively uniform dispersal of lighter colored
pigments over
the surface while limiting differential absorption into the various areas of
differing
porosity inherent on the surface of a decorative panel formed from the
materials
outlined in Examples 2 or 3. This results in a wider range of stain colors
available
for discerning customers, but reduces the economic and durability benefits of
using
unprimed surfaces.
Thus the subject invention pertains to a door light frame or decorative
panel comprised of opposing inner and outer molded members, these members
generally being formed from the same material, and featuring approximately the
same
surface texture as the molded door skin or side light skin into which the door
light
frame is to be inserted, these components manufactured from thermoset molding
resins or molding resins which become thermoset during the molding process or
through a post-molding treatment. The door light frames or decorative panels
are
preferably made from a thermoset molding resin which is a glass-fiber
reinforced
sheet molding compound or a thermoset molding resin which is a lignocellulosic
fiber
filled phenolic compound.
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The outer molded members are preferably suitable for prolonged
exposure to the weather. To this end, for example, the outer molded door light
frame may consist of a thermoset molding resin which is lignoceilulosic fiber
filled
phenolic compound containing or coated with one or more hydrophobicizing
agents.
Preferably, the lignocellulosic fiber-filled phenolic compound is primarily a
phenol-
formaldehyde novolac, and the hydrophobicizing agent contains organosiloxane
and/or organosilane resins bearing reactive functional groups. Preferable
hydrophobicizing agents contain organosiloxane or silane resins bearing
reactive
functional groups. A linear amino-functional siloxane may be intimately mixed
with
the lignocellulosic fiber in a refiner, or the silane may be applied to the
surface of
lignocellulosic fiber mat prior to molding.
The subject invention further pertains to a door light frame or
decorative panel comprised of opposing inner and outer molded members, these
members being formed with approximately the same surface texture as the molded
door skin or side light skin into which the door light frame or decorative
panel is to
be inserted, wherein the door light frame or decorative panel demonstrates
staining
color, color uniformity, and gloss, as well as texture appearance closely
matching the
staining color, color uniformity, and gloss as well as texture appearance of
the door
skin or side light skin into which the door Light frame or decorative panel is
inserted.
The door light frame or decorative panel is composed of materials such that
the stain
and topcoat applied to the door light frame or decorative panel is strippable
without
damage visible to the unaided eye using paint strippers, particularly those
employing
powerful solvents such as methylene chloride as a primary ingredient.
The door light frames, decorative panels, or plant-on molding
members of the present invention preferably are made from composites based on
thermoset molding resins or molding resins that become thermoset during the
molding process or through a post-molding treatment, which are molded under
pressure of 1,000 to 15,000 Kpa to a predetermined thickness of 1.25 to 19 mm,
the
molding operation occurring at temperatures of 121°C-218°C. In
one preferred
embodiment, the door light frame, decorative panel, or plant-on molding member
is
molded from sheet molding compound molded at 2,500 to 5,100 Kpa at molding
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temperatures of 150°C-180°C. In a second preferred embodiment,
the door light
frame, decorative panel, or plant-on molding member is molded from a
composition
containing 1-24 weight % novolac phenol-formaldehyde mixed with wood fiber,
molded under pressure ranging from 2,500 to 51,000 Kpa at molding temperatures
of 200°C-218°C. Such molding compositions are termed herein
"novalac/partially
digested wood fiber compositions".
_ In a further embodiment, the door light frame, decorative panel, or
plant-on molding member is suitable for prolonged exterior exposure, and is
made
from composites based on thermoset molding resins or molding resins that
become
thermoset during the molding process or through a post-molding treatment,
these
composites being of approximately the same material as the door skin or side
light
skin in to which they are inserted, the composite having been impregnated with
coatings restricting moisture and moisture vapor transmission into the member,
the
member being molded under pressure of 1,000 to 15,000 Kpa to a predetermined
thickness of 1.25 to 19 mm at temperatures of 121 °C-218°C. Most
preferably, the
door light frame, decorative panel, or plant-on molding member is produced
from
a composite containing 1-24 weight % novolac phenol-formaldehyde intimately
mixed with wood fiber applied in the fiber refining process, mixed with the
fiber
before mat forming, or impregnated on the mat before pressing, the composite
having
alkylalkoxy-siloxane intimately mixed with the fibers that are part of the
composite
during refining, mixed in the fiber before mat forming of the composite,
impregnated
on the composite mat before pressing, or applied to the composite mat or tool
surface
in contact with the composite mat as part of the pressure fotrning operation,
and the
surfacial layer of the composite mat impregnated with silane compounds, the
composite molded under pressure from 2,500 to 5,100 Kpa at molding
temperatures
of 200°C-218°C.
In a yet further embodiment, a plant-on molding is comprised of a
molded member, this member being formed from approximately the same material
and featuring approximately the same surface texture as the molded door skin
or side
light skin into which said plant-on molding is to be affixed, these members
made with
thermoset molding resins or molding resins that become thermoset during the
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molding process or through a post-molding treatment, preferably glass-fiber
rein-
forced sheet molding compound or lignocellulosic fiber filled phenolic
compound.
As with other embodiments, these exterior plant-on moldings are suitable for
prolonged exposure to the weather, and most preferably comprise
iignocellulosic
fiber-filled phenolic compound with a hydrophobicizing agent. The
hydrophobicizing
agent preferably comprises organosiloxane and/or organosilane resins bearing
reactive
functional groups. Most preferably, the plant-on molding is formed with
approxi-
mately the same surface texture as the molded door skin or side light skin on
to
which the plant-on molding is placed or inserted, and further demonstrates
staining
color, color uniformity, and gloss, as well as texture appearance which
closely
matches the staining color, color uniformity, and gloss as well as texture
appearance
of the door skin or side light skin into which the plant-on molding is placed
or
inserted. These plant-on moldings are preferably strippable without damage
visible
to the unaided eye using paint strippers, even when strippers employing
methylene
chloride as a primary ingredient are used.
The subject invention also pertains to door assemblies comprising at
least one compression molded skin and at least one separately manufactured
door
light frame, decorative panel, or plant-on molding of the subject invention
which is
stainable with the same or substantially the same stain as the door panels
proper, to
provide a stained door light frame or other component described above which
has
substantially the same color and depth of color as the door skin itself. In
other
words, the separately manufactured component will stain in approximately the
same
manner as the door skin itself.
It is believed that door light frames, plant-on moldings, and decorative
panels have
not been previously produced from the thermoset resin compositions of the
present
invention because of the difficulties expected in molding articles such as
those
described by U.S. patents 4,523,408 and 4,839,989. However, it has been
surprisingly discovered that even relatively complex moldings can be produced
by the
subject process.
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Moreover, it has been surprisingly discovered that doorlights and
plant-on moldings and panels may be produced without the need for physical
methods
of attachment, these elements being mounted unto the door by means of a film
adhesive which may also serve as a sealant in the case of door lights. In the
case of
decorative panels and the like, the use of film adhesives allows the mounting
of
panels and the like without first forming a hole in the door to receive
oppositely
inserted mating elements as disclosed by the prior art. This construction
allows for
a stronger and more weatherproof assembly.
In an alternative embodiment, one doorlight frame member may be
simply.molded and designed for adherence by means of adhesive, while the
mating
member may be designed for conventional mounting by screws, deformable
inserts,
etc. In such a case, if the glass in the doorlight is broken, it may be
readily replaced
by removing the conventionally mounted member.
For example, standard doorslabs equipped with ten panels were
measured for thermal deflection and twist. The doorslab having the panels
mounted
with adhesive tape exhibited approximately the same overall thermal
deflection, with
greater deflection at the top of the door but less at the bottom. Torsional
stiffness of
the adhesive-applied panel door was outstanding, however, exhibiting almost
three
times the torsional stiffness of a similar door having cutouts and panels
mounted
within the cutouts by conventional (screw) fastening methods.
Numerous adhesive tapes are suitable, and many are commercially
available. A preferred tape, however, is VHB 4930 tape manufactured by the 3M
Company. It is generally necessary to wash the areas on the door slab which
will be
bonded to the panels with an aggressive solvent to remove waxes, mold
releases, etc.
A suitable solvent is Tape Primer 94 available from 3M. Isopropanol,
methylethylketone, and similar solvents are also suitable. Adhesively bonded
elements showed no sign of adhesion loss upon weathering, or exposure to
mineral
spirits, Glass PlusT"" Window Cleaner, Fast-n EasyT"" Amonia Cleaner, Acetone,
3M
brand Safest Stripper Stripping Compound, or ZarT"' methylene chloride-based
paint
and varnish remover.
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In the claims, the term "outside" as it refers to surfaces, is the surface
of the door skin, sidelite surface, etc., to which a door light frame, plant-
on molding,
or decorative panel is to be affixed, as opposed to an "inside" surface which
is
internal to the door, etc. By the term "exterior" is meant a surface which is
exposed
to the elements in a house or building, as opposed to an "interior" surface
which
faces the building interior.
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