Note: Descriptions are shown in the official language in which they were submitted.
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METHODS AND APPARATUS FOR REPLICATING
ORIGINAL OBJECTS
BACKGROUND OF THE INVENTION
1. Field of the Invention.
The invention relates to the general field of methods and
apparatus for replicating the characteristics of an original object such
as a stone or stone panel in a cast article. More particularly, the
invention relates to the field of such methods and apparatus further
incorporating into the cast article useful shapes and properties not
present in the original object but normally helpful in constructing
commercial structures such as facades and walls from the cast
articles.
2. Discussion of the Background.
Many people have attempted to manufacture items simulating
the contours and colors of an original object such as a natural article,
but produce an item that either does not look authentic or poorly
reproduces the original object in its entirety. One example is
Formica , a hard plastic substrate used to cover countertops and the
like. Some forms of Formica were impregnated during manufacture
with dyes or other colored material to simulate the look of wood or
stone. However, the simulation was not convincing because the
Formica was fiat. Also, it did not have the texture of the original
object it purported to simulate.
Another example is Corian . This was made from plastic in
the form of sheets of varying thickness for use as countertops and
related structures. Most forms of Corian were made by mixing filler
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materials with plastic and the resulting product was colored much like
the filler material used during manufacture. Some forms of Corian
were made to resemble stone. However, the simulation was not
appealing because Corian was largely fiat and it also did not have
the texture of the natural articles it purported to simulate.
Yet another example is Linoleum . This was made from
various plastics and fillers and was sold in the form of sheets or rolls,
principally for covering floors with a wear-resistant surface. While
some forms of Linoleum were colored and textured to resemble
natural articles, the simulation was still not convincing. The colors
were artificial and the texture so regular as to dispel the notion of a
natural articles.
Still another example is plastic floor tiles. These were typically
squares of regular size. They were intended to be butted against one
another once a mastic had been applied, and some were both colored
and textured to resemble natural articles. However, the colors were
often unconvincing. Further, the same was true for the textures,
which were not only shallow but also discontinuous where one tile
butted up against another.
Another example is exterior siding designed to replace or cover
some or all of the exterior of outdoor structures, including houses.
This siding typically was made of plastic or aluminum and was marked
or embossed in an effort to simulate natural articles. However, the
simulation was not appealing. The colors were unconvincing and the
textures were not only shallow and unrealistic but also discontinuous
where one piece of siding butted up against another.
Another example is cultured stone. This was cast from cement
and aggregate and simply mimicked the characteristics of real stone.
It could not be molded any differently from the natural article and
required the same methods for installation as real stone.
Processes for casting plastics are disclosed in United States
Patent No. 5,750,583 to Gansen et al. and United States Patent No.
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3,883 627 to Fitts. Gansen et al. disclosed a process for the
preparation of polyurethane products in which a plastic film was
positioned in a mold, the mold was closed, a polyurethane reaction
mixture was injected into the mold, and the product was removed from
the mold once the reaction mixture had fully reacted.
Fitts disclosed a process in which a heat curable elastomeric
sheet comprising a curing agent and either urethane elastomeric gum
stock or silicone gum stock was placed over a master to be copied.
The heat curable elastomeric sheet was one that did not cause
inhibition between the master and the heat curable elastomeric sheet.
Next, the elastomeric sheet was vacuum drawn against the master
and the master sheet material was enclosed in a frame. A foamed
polymeric backing was then formed in situ to force the heat curable
elastomeric sheet against the master to copy the shape of the master.
The heat curable elastomeric sheet was then cured in the shape of
the master. Finally, articles were molded in the shape of the master in
a mold constructed from the cured elastomeric sheet material.
A decorative plastic moulding was disclosed in 5,372,869 to
Drexinger et. al. The moulding comprised two moulding pieces, each
with a decorative face, a back, two sides, and two ends. Each end of
each piece had a 45 degree angle pre-mitered cut relative to the
plane of the decorative face, with the pre-mitered cuts of each piece
being in parallel planes. Each side of each piece was in a plane at a
45 degree angle to the plane of the decorative face, with the side
planes converging at a position spaced from the back of the piece.
The two moulding pieces were made of fire rated polyurethane.
Finally, a method for molding an artificial rock was disclosed in
United States Patent No. 4,940,558 to Jarboe et. al., This method
entailed selecting a rock for reproduction and creating a flexible
rubber mold and supporting cradle having a mold cavity conforming to
the exterior of the rock. The mold has a substantial degree of
flexibility and is created by applying an uncured liquid rubber forming
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material to the rock and curing the uncured liquid rubber forming
material to produce the rubber mold. The cradle is formed by
applying or spraying a low density urethane foam forming mixture to
the exterior of the rubber mold to provide a self-supporting cradle and
spraying a two-sided urethane composition into the mold cavity. The
urethane composition comprises an isocyanate side and a polyol side
and is mixed in a spray gun in a spray-in-mold process to build up the
molded artificial rock to a desired thickness. The cradle and mold are
then stripped away after curing.
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SUMMARY OF THE INVENTION
The present invention involves methods and apparatus for
producing cast articles with characteristics of original objects such as
a stone panel. The cast articles can replicate the contours, textures,
and colors of all or a portion of the original object and can be made in
any shape or size and specifically can be formed to simulate rock
walls, carved stone architecture details, and other construction
components normally created by stone masons or sculptors on site
and at a high cost. The processes used in making the cast articles
include the production of a series of molds. The molds seek to
replicate the size, shape, contour, and surface texture of an original
object with or without modifications to the original object. For
example, the original object may be a wall with multiple and different
stone sections as would occur if a stone mason Greated a wall from
individual stones. It may also be an architectural piece such as a
carved stone element with a natural outward appearance in a
customized shape. A master reproduction is used in this invention to
form molds from which commercial quantities of cast articles can be
made.
The general procedures and materials specifically disclosed
herein have wide application. In most of the embodiments, an original
object is physically placed in a frame to make a mold. However,
rather than binging or modifying an original object (natural or
manmade) to fit within the confines of such a frame, an impression
can be taken of at least a portion of the original object where it is
located. In this regard, an impression of a portion of a large object
found in nature (e.g., a portion of a huge, immovable stone, boulder,
etc.) could be taken in the field. To this end, an open faced box could
be securely held, or constructed, around a portion of the object that
one desires to replicate. The securely held box could then be sealed
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around its open face edges and filled with a first impressionable
material. This first impressionable material could be a flowable mold
making material such as a semi-liquid silicone that, upon curing or
drying (in the box), captures the surface morphology, texture, etc. of
the object to be replicated. This first impressionable material could
also be a precursor to an inflexible material (e.g., a polymeric material
or a non-polymeric material) such as those used to create certain
hereinafter more fully described thermosetting polymeric materials.
These impressionable materials are capable of replicating the surface
morphology, texture, etc. of a solid object they contact while in a semi-
fluid (impressionable) state. They then maintain that surface
morphology, texture, etc. after the originally impressionable material
has cured, dried, cooled, etc., and been removed from its impression-
forming contact with the solid object it replicates. In a less preferred,
but still operable embodiment of these alternative procedures, such
impressionable materials could even be a non-polymeric material
(e.g., a crystalline material) such as plaster of Paris.
Many of the preferred embodiments of this invention involve
taking impressions of manmade objects (e.g., bricks, manmade
carvings in the face of a block of marble, wood, metal, thermoset
resin, ceramic material, etc., three dimensional manmade objects
such as castings of objects of art, mold parts, etc.). In such cases, a
resulting impression-bearing first mold material can be employed in
ways hereinafter described in order to produce a master reproduction.
A final product or cast article bearing a replication of the surface
morphology of the original object (be it a natural or manmade object)
can then be made. Generally speaking, the herinafter decscribed
processes for making a final product or cast article that replicates a
portion of a surface of the original object may comprise: (1) making a
first mold that replicates at least part of the surface of the original
object, (2) filling the first mold with a first castable material to produce
a cast reproduction, (3) modifying the cast reproduction to form a
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master reproduction, (4) making a second mold that replicates at least
part of the surface of the master reproduction, (5) filling the second
mold with a second castable material, and (6) curing the second
castable material to produce a cast article that replicates at least a
portion of the surface of the original object.
One particularly preferred process for making the cast articles
that replicate the surface of an original object such as a natural article
comprises the steps of modifying the original object to a
predetermined size and configuration (such as cutting two or more
stones to fit together or to carve a piece of stone) and thereafter
making a mold of at least part of the modified original object (e.g.,
modified natural article). The mold is then filled with a castable
material to produce a cast reproduction of at least part of the surface
of the modified original object (e.g., modified natural article). Next,
the reproduction may be modified for construction and installation
purposes to a predetermined size and configuration to make a master
reproduction. The final cast article may then be made from a mold
replicating at least a part of the surface of the master reproduction.
Another method of the invention involves making reproductions
or cast articles of architectural details, such as cornices or moldings
that replicate the surface of a natural article (e.g., stone). The method
comprises the steps of making a mold of at least part of the surface of
the stone and then lining the inner surface of a support structure with
the mold. The support structure with the surface mold is filled with
castable material creating a master reproduction with the replicated
stone surface texture incorporated into the casting in the three-
dimensional shape desired.
Apparatus of the invention as disclosed can be used in
systems for the production of cast articles that replicate the surface of
an original object. These systems include two types. One is a
continuous conveyor system and a second is a single mold operation
that is individually filled. These may be placed in a multiple mold
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stack for curing or cured individually with or without pressure. The
conveyor system comprises a conveyor, one or more molds
positioned on the conveyor (each of which molds replicates on at least
part of its surface the surface of the original object), a dispenser
positioned adjacent to the conveyor for filling one or more of the
molds with a castable material, and second conveyor positioned
adjacent to the first conveyor for substantially confining the castable
material to the molds. This system can further comprise one or more
dispensers of castable material, liquid or powdered coloring agents
secondary additives, such as UV blockers, or solvent positioned
adjacent to the first conveyor, as well as a heater for heating the
molds and drying any paint, coloring agent or solvent placed in them.
In another method, the curing may occur in separate closable support
structures, with or without pressure systems. These may be individual
or aggregated for efficiency and production.
These methods and apparatus can be practiced or configured
in a number of variations. For example, molds can be placed in
closable support structures to facilitate casting of the article. The
closable support structure can be made of metal, wood, plastic or the
like and lined with an inert material to prevent adhesion of castable
material to the rigid support structure.
The cast articles can be colored by placing a powdered or
liquid coloring agent (or both) into the mold before the mold is filled
with castable material. In another variation, a coloring agent is mixed
into the castable material before the mold is filled with the castable
material. Additional additives may be added if desired for purposes of
protecting against environmental or other conditions.
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In accordance with one aspect there, there is provided a method for
making a cast thermosetting polymer masonry wall panel reproduction that
replicates on at least a part of its exterior surface, the surface and surface
texture
of an array of articles each of which is one of a natural stone article or a
brick
article while simultaneously imparting color to the exterior surface of the
replicated articles in the cast masonry wall panel reproduction, the method
comprising: using a mold having a cavity that replicates the surface of each
one
stone or brick article to be replicated in the array of articles in the
masonry wall
panel reproduction; introducing castable thermosetting polymer material into
the
cavity of the mold; adding a powdered iron oxide compound to the cavity in the
mold prior to introducing the thermosetting polymer material into the mold;
locating the powdered iron oxide compound on a surface of the cavity to be
retained by the introduced thermosetting polymer material over the exterior
surface of each replicated article in the cast masonry wall panel
reproduction;
curing the thermosetting polymer material sufficiently in the mold to retain
the
powdered iron oxide compound over the exterior surface of each replicated
article in the cast masonry wall panel reproduction; and imparting color and
surface texture to the exterior surface of each replicated article from the
powdered iron oxide compound retained over the exterior surface of each
replicated article in the cast masonry wall panel reproduction.
In accordance with another aspect, there is provided a method for making
a cast thermosetting polymer reproduction that replicates on a part of its
surface,
the surface of an object found in nature, the method comprising: using a mold
having a cavity that replicates the surface of the object to be replicated;
introducing castable thermosetting polymer material into the cavity in the
mold;
adding a powdered metal oxide pigment and a pigment binder comprising a
mixture of silicone dioxide and polytetrafluoroethylene to the castable
thermosetting polymer material to impart color to the cast reproduction; and
curing the thermosetting polymer material sufficiently in the mold to retain
the
shape of the cast reproduction.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. I through 8 below relate to one embodiment of the
invention of this application:
FIG. I depicts three pieces of a natural article, in this case
stone, cut to appropriate size and set side by side to form a panel or
portion of a wall.
FIG. 2 depicts the stone pieces surrounded by a wooden dam
and with silicone poured over the stones.
FIG. 3 depicts a first mold after it is removed from a frame such
as in Fig. 2.
FIG. 4 depicts a master reproduction made from the mold of
Fig. 3 and subsequently modified to generate a master reproduction
by removing material to form undercuts and creating extensions for
use in production and installation.
FIG. 5 depicts a detail of the undercut of FIG. 4.
FIG. 6 depicts a detail of the fit between two polyurethane
reproductions showing the undercut and extensions.
FIG. 7 depicts a second mold 'made from the master
reproduction of FIG.4.
FIG. 8 depicts the second mold placed in a closable support
structure.
FIGS. 9 through 24 below relate to two other embodiments of
the invention of this application:
FIG. 9 depicts a piece of stone onto which a castable material
such as silicone has been poured.
FIG. 10 depicts the removal from the stone of the silicone mold
of FIG. 9 after it has cured.
FIG. 11 depicts a preshaped wooden mold or master part of an
architectural detail lined with the silicone mold, such as in FIG. 10,
used in forming the architectural details such as cornices or moldings.
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FIG. 12 depicts a side view of the assembly of FIG. 11.
FIG. 13 depicts the assembly of FIG. 12 filled with castable
material to make a master reproduction.
FIG. 14 depicts a side view of the assembly of FIG. 13.
FIG. 15 depicts the removal of the master reproduction from
the assembly of FIG. 13.
FIG. 16 depicts a side view of the removal of the master
reproduction from the assembly of FIG. 13
FIG. 17 depicts the master reproduction,
FIG. 18 is a side view of the master reproduction of FIG. 17
supported by on a wooden board.
FIG. 19 depicts the master reproduction of FIG. 17 placed into
a second support structure into which silicone has been poured to
form a mold.
FIG. 20 depicts the resulting silicone mold placed in a closable
steel support structure.
FIG. 21 depicts the assembly of FIG. 20 filled with castable
material to produce a cast article.
FIG. 22 illustrates a characteristic of the flexible mold in that it
can be manipulated into alternate shapes.
FIG. 23 illustrates a mold for corner pieces.
FIG. 24 illustrates corner pieces of a rock wall cast from a mold
such as in FIG. 23.
FIG. 25 depicts a system for the production of cast articles with
first and second conveyors moving in combination.
FIG. 26 illustrates the preparation of a mold including pouring
coloring and UV protection additives in the mold and treating itt with
solvent or wetting agents, such as denatured alcohol.
FIG. 27 depicts another system for the production of cast
articles.
FIG. 28 illustrates the cure apparatus of one embodiment to
enable an efficient use of space by stacking the filled molds for curing.
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FIG. 29 illustrates the closable support structure with a
covering top to keep pressure on the molds during the cure time.
FIG. 30 illustrates the closable support structure in a non-
pressurized state.
FIG. 31 illustrates the closable support structure in a
pressurized state.
FIG. 32 illustrates a wall formed with multiple panels.
FIG. 33 is a side view taken along line 33-33 of FIG. 32
illustrating the joining of various elements of the wall.
FIG. 34 illustrates the closable support structure in an open
position with a mold in it.
FIG. 35 illustrates the closable support structure with the top in
a closed position.
FIG. 36 illustrates a view taken along line 36-36 of FIG. 35
showing the top with a protrusion into the mold cavity and into the
castable material in the mold.
FIG. 37 illustrates the same view as FIG. 36, but after the
castable material has expanded and excess castable material has
exited the vents in the top.
FIG. 38 illustrates the closable support structure after the
casting material is cured showing the excess castable material that
exited the vents and showing the hollowed-out portion of the cast
article caused by the protrusion of the top.
FIG. 39 illustrates the cast article.
FIG. 40 illustrates another closable support structure and a
second mold before any castable material is placed in the mold.
FIG. 41 illustrates the closable support structure with the top
closed.
FIG. 42 illustrates a side view taken along line 42-42 of FIG. 41
showing the closable support structure, the second mold, the castable
material, and the vents where excess castable material has exited.
FIG. 43 illustrates the cast article.
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FIG. 44 illustrates the closable support structure with the top
opened and the side support opened to allow for the removal of the
cast article and second mold after casting.
FIG. 45 illustrates an alternate top for the closable support
structure showing vents along the top but without the protrusion into
the mold cavity of FIG. 36.
FIG. 46 illustrates the top of FIG. 45 closed over the mold.
FIG. 47 illustrates the cast article removed from the mold of
FIG. 45.
FIG. 48 illustrates the use of ribs formed by the vented top of of
FIG. 45 in an installation as a flat construction surface to provide
pathways.
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DETAILED DESCRIPTION OF THE INVENTION
While the invention is susceptible to various modifications and
alternative forms, specific embodiments are shown by way of example
in the drawings and are described in detail below. The description
and drawings are not intended to limit the invention to the particular
embodiments disclosed. On the contrary, the invention embraces all
modifications, equivalents, and alternatives falling within the spirit and
scope of the invention as defined by the appended claims.
FIGS. I through 8 depict one preferred embodiment of the
invention of this application. The process described is for making flat
panel reproductions for use in structures. These panels replicate the
surface of an original object such as a natural stone panel in a form
that would be difficult and expensive to make with natural stone and
would require a stone mason to design and build onsite.
In FIG. 1, natural articles such as flagstones 102, 104 and 106
are first selected, altered, and arranged to create a modified natural
article (i.e., stone panel 204) supported by wooden board 100. As
shown, grout 110 has been placed in the spaces between flagstones
102, 104 and 106. Wooden grout strips 200 have also been added
along the sides of flagstones 102, 104 and 106 to facilitate the
production of replicates that will lock together when assembled in
quantity. The stone panel 204 has been walled in with wood strips
300 that form a perimeter for a liquid mold material 400 (see FIG. 2)
that will be subsequently poured into the receptacle made up of stone
panel 204 and the frame of wood strips 300. The uncured silicone
400 of FIG. 2 may be treated with a vacuum to eliminate any bubbles
prior to being poured.
FIG. 3 illustrates the first flexible mold 600 which is formed
after the poured silicone of 400 of FIG. 2 has cured and been lifted off
the stone panel 204. The mold 600 as shown depicts the negative
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impression of the surface of the stone panel 204. This first mold 600
is then filled with a first castable material, such as expandable
polyurethane plastic, to form a first cast reproduction that duplicates
the surface texture and major contours of the original object (i.e., the
stone panel 204) and any grout surfaces.
FIG. 4 depicts a first master reproduction 700 made from a
substantially square mold in essentially the same manner that the
rectangular mold 600 of FIG. 3 was created. Extensions 702 and 706
in FIG. 4 are formed by grout strips like 200 in FIG. 2. In addition,
sides 704 and 708 of panel 700 have been undercut. Panel 700 as
modified with undercuts 704 and 708 can also be used herein as a
master reproduction. This undercutting can be accomplished by any
known method for removing material from a panel including milling,
sawing, knife cutting, and laser cutting. A detail of the undercut is
shown in FIG. 5 with FIG. 6 depicting how an adjacent extension 702
and undercut 704 of final cast articles 900 and 901 made according to
the processes herein will overlap when placed against one another.
FIG. 7 depicts a second mold 1000 made from a first master
reproduction such as panel 700 in FIG. 4. Mold 1000 has cavities
1002, 1004, 1006 and 1008 corresponding to stones in an original
panel. Mold 1000 was made using essentially the same procedures
as those followed to make rectangular mold 600, except that outer
grout strips 200 were not added.
In FIG. 8, mold 1000 has been placed in a closable support
structure 1112, which in turn is made up of steel subframes 1114 and
1116 which are rotatably connected by hinge 1110. Upper subframe
or top 1114 is fitted with a sheet of inert plastic 1113 to prevent the
polyurethane or other castable material from adhering thereto. The
curing may be accomplished without a closable support structure if
desired. Additionally, with some castable materials such as
expansible foam plastics, the closable support structure may apply
pressure to the mold during cure.
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In practice, a cast article is made by filling lower subframe 1116
with an uncured, second castable material such as polyurethane
plastic and rotating subframe or top 1114 to cover subframe 1116.
Latches 1106 and 1108 are then engaged with brackets 1102 and
1104 and closed to effect a tight engagement between subframes
1114 and 1116. Inert material such as plastic sheet 1113 prevents
the uncured polyurethane plastic from sticking to subframe 1114.
Once the second castable material has cured, latches 1106 and 1108
are disengaged from brackets 1102 and 1104, subframe 1114 is
rotated away from subframe 1116, and the cast article is removed
from subframe 1116.
A polyurethane plastic, cast article made as described above
can be colored on the side that replicates some or all of the cavities of
mold 1000. In one such method of coloring, one or more powdered
cement or ferric oxide dyes or other powdered coloring agents are
placed in a predetermined or random pattern into at least one of the
cavities 1002, 1004, 1006, and 1008 of mold 1000 of FIGS. 7 and 8.
The best coloring agent is powdered ferric oxide which can be in
many different colors. For best results, use of multiple colors
randomly sprinkled into the cavities gives the appearance of natural
coloring and weathering. A fine mist of a wetting agent such as water
or denatured alcohol can then sprayed or brushed over the coloring
agent or agents until the powder dissolves or is wetted. The cavity or
cavities of mold 1000 so treated are then dried. When the second
castable material or polyurethane plastic is introduced into mold 1000,
the coloring agent or agents become part of the surface of the
uncured polyurethane plastic, resulting in a polyurethane cast artilce
that is partially or wholly colored on the surface that replicates the
contours of mold 1000. This is illustrated and discussed later in
conjunction with FIG. 26.
In another method of coloring, a second castable material, one
or more coloring agents such as paints or powders can be introduced
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in a predetermined or random pattern into at least one of the cavities
of mold 1000. The cavity or cavities of mold 1000 so treated are then
dried. When uncured polyurethane plastic is introduced into mold
1000, the dried paints or powders are picked up by the uncured
polyurethane plastic, resulting in a cast article that is partially or wholly
colored on the surface that replicates the contours of mold 1000.
In yet another method of coloring a cast article, one or more
liquid or powdered cement dyes or other powdered coloring agents
are mixed with the second castable material before being introduced
into mold 1000. After the material such as uncured polyurethane
plastic is introduced into the mold 1000 and cured, the resulting cast
article is uniformly colored both internally and externally. In all of
these methods, the powder or liquid may include protective additives
to aid the resistance of weathering or other deleterious environmental
conditions for the cast article. This may be an ultraviolet blocking
agent or some other material to protect against any undesirable
conditions.
FIGS. 9 through 24 depict another preferred embodiment of the
invention of this application. The process described is for making
three-dimensional replicas. These replicas reproduce desirable
surface textures of the original object (e.g., natural stone) in a form
that would be difficult or impossible to make in natural stone. The
final cast article then appears to be three-dimensional stone with the
desirable texture on the outside.
FIG. 9 depicts the first step in making a flexible silicone mold of
the stone 1200 bearing the surface of the natural article for
replication. Stone 1200 as illustrated is fitted with a dam 1202 on the
upper surface thereof. The parts of dam 1202 visible in the side view
of FIG. 9 are wood strips 1204 and 1206. Dam 1202 serves to
contain the uncured silicone 1208 poured onto stone 1200 in FIG. 9.
In FIG. 10, the uncured silicone 1208 of FIG. 9 has cured into
the first flexible mold 1300 of FIG. 10. To aid in lifting the mold 1300
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off the stone 1200, the dam 1202 can be opened as shown in FIG. 10
by removing the wood strip 1204 of FIG. 9. This mold 1300 then
replicates the desired texture of the surface of the stone 1200 which
may be weathered limestone, porous marble or etched or carved
graphics and designs.
A rigid support structure 1412 is depicted in FIG. 11 comprising
a bottom board 1400, side boards 1404 and 1408, end board 1406,
and contour board 1402. The contour board 1402 determines the
decorative three-dimensional shape of the cast reproduction. In some
cases, the three-dimensional shape may be an existing carved shape,
such as a sculpted stone piece. The rigid support structure 1412 can
be lined with a flexible mold 1410, which can be a portion of the
flexible mold 1300 of FIG. 10 trimmed to fit inside support structure
1412. The first flexible mold 1300 has a textured surface 1302 and a
smooth surface 1304. The smooth side 1304 of the first flexible mold
1300 faces the inner surfaces of rigid support structure 1412, while
the textured side 1302 faces away from the interior of rigid support
structure 1412. FIG. 12 in this regard is a side view of the rigid
support structure 1412 of FIG. 11.
In FIG. 13, the rigid support structure 1412 has been filled with
a first castable material such as expandable polyurethane plastic
1600 and the rigid support structure 1412 closed with top 1602. A
cross section from the end of the rigid support structure 1412 of FIG.
13 is shown in FIG. 14. The first flexible mold 1300 is thin enough to
easily conform under the cure pressures to duplicate the contours of
the rigid support structure 1412. The mold 1300 forms a high fidelity
veneer on the support structure 1412 adopting the contours of the
textured side 1302.
In FIG. 15, top 1602 has been removed from rigid support
structure 1412 and the cured polyurethane master reproduction 1800
removed from rigid support structure 1412. The surface of master
reproduction 1800 that contacted mold surface 1302 then replicates
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the surface of stone 1200. A cross section from the end of rigid
support structure 1412 of FIG. 15 is shown in FIG. 16.
FIG. 17 depicts the master reproduction 1800 after being fully
removed from rigid support structure 1412 and placed on top of a
board 2000 to form assembly 2002. A cross section of assembly
2002 is shown in FIG. 18.
In FIG. 19, assembly 2002 has been combined with a second
rigid support structure 2212. Structure 2212 comprises side boards
2203 and 2206, top board 2208, and spacer board 2210. The second
rigid support structure 2212 is sized and configured internally so that
there is a relatively uniform gap between the master reproduction
1800 and the inner surfaces of second rigid support structure 2212.
When uncured silicone is poured into the open top of the second rigid
support structure 2212 and allowed to cure, a second flexible mold
2200 of the master reproduction 1800 results.
FIG. 20 depicts a third rigid support structure 2300. While the
first rigid support structure 1412 and second rigid support structure
2212 may be made of wood, the third rigid support structure 2300
may be made of structural steel or metal as it will be used to create
multiple cast articles and thus, needs to be sturdy. Rigid support
structure 2300 is sized to receive the silicone mold 2200 as closely as
possible. Flexible mold 2200 of FIG. 20 has been placed in closable
support structure 2300, which in turn is made up of steel subframes .
These subframes are rotatably connected by hinge 2306 with upper
subframe or top 2304 being fitted with a sheet of inert plastic 2314.
In practice, a second cast article is made by filling the mold 220
in the closable support structure 2300 with uncured polyurethane
plastic and rotating top 2304 to cover mold 2200. Latch 2308 is then
engaged with bracket 2310 and closed to effect a tight engagement.
Inert plastic sheet 2314 prevents the uncured polyurethane plastic
from sticking to the top 2304. Once the polyurethane plastic has
cured, latch 2308 is disengaged from bracket 2310 and top 2304 is
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rotated away as shown in FIG. 21. A resulting, cured cast article 2400
of polyurethane such as shown in FIG. 21 is then removed.
Polyurethane cast articles made as described above can also be
colored by various methods, including those previously discussed.
FIG. 22 illustrates a characteristic of the flexible molds like
1300 of FIG. 10 in that they can be manipulated for a particular
installation into alternate shapes such as a curved wall, a molding, a
support beam, or other architectural detail. In such cases, the final
cast article of the processes of the present invention will have the
desired texture on the outside surface replicating the surface texture
of the original object (e.g., stone panel). Such a result from real stone
would require a very skilled stone mason to work onsite many hours to
shape each stone element to fit together and to curve uniformly. In
the case of moldings or carved stone replicas, a sculptor would have
to sculpt the stone, after finding the appropriate stone block. In the
processes of the present invention, the selected texture is replicated
on an easily constructed surface made from easily machined
materials, such as wood or plastic. The final cast article in this regard
is a unique benefit of the disclosed process.
FIG. 23 illustrates a second flexible mold 2450 to produce a
second master reproduction such as the corner piece 2452 shown in
FIG. 24. The corner piece 2452 is formed as a single piece and thus,
does not have the joint of two, separate wall pieces.
FIG. 25 depicts a system 2500 for the continuous production of
polyurethane cast articles. First lower conveyor 2502 is loaded
continuously with molds 2504, which are made from one or more
original objects or master reproductions thereof. Once a mold 2504 is
placed on lower conveyor 2502, one or more coloring dispensers
2506 introduce one or more coloring agents, powdered or liquid, as
well as wetting agents, such as water or alcohol where required, into
the cavities in the mold 2504 so as to color the cast articles produced
from molds 2504 by various methods, including the methods
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described above. Lower conveyor 2502 then conveys molds 2504 to
one or more heaters 2508, which dries all coloring agents, paints and
water in molds 2504, and also heats the mold 2504.
Lower conveyor 2502 then conveys molds 2504 to a second
castable material dispenser 2510, which fills molds 2504 with a
castable polyurethane. Next, lower conveyor 2502 conveys molds
2504 under second upper conveyor 2512, which inhibits the castable
urethane from foaming beyond the confines of molds 2504. The
conveyor 2512 preferably has a surface of inert material so the
castable material will not stick to the conveyor 2512. Depending on
the formulation of the castable material, this second conveyor 2512
may need to apply pressure to the mold during the cure. Finally,
lower conveyor 2502 conveys molds 2504 beyond the second or
upper conveyor 2512 and onto receiving platform 2514, where the
cured cast articles are removed from molds 2504.
Another embodiment of the production process and a cure
apparatus is illustrated in FIGS. 26 and 27. FIG. 26 illustrates the
mold preparations with coloring agents placed in the cavities. The
brush spreads the agents and wets them with a wetting agent, such
as denatured alcohol or water. The wetting agent must not cause the
mold to swell as this will degrade control and quality of the accuracy
of the replicas of the stone surface texture. The activities of FIG. 26
occur in FIG. 27 in areas 20, 21 and 22. Area 24 is a drying area to
dry the incoming mold M of any wetting agent before the polyurethane
fills the mold M. In FIG. 27 a flash heater 25 is illustrated to quickly
dry the mold. In area 26 the dry, prepped molds are filled with
polyurethane.
FIG. 28 depicts a stack 14 of closable support structures. It
can be a multi-layered structure with bottom or layers to support each
mold. In this embodiment each layer operates by pneumatic,
mechanical or hydraulic forces to cause a top or platen to come down
onto the mold form with side supports for the cure of the polyurethane
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to inhibit the expansion and increase the density and thus the fidelity
of the reproduction. A plastic sheet or inert sheet is inserted between
the top and the filled mold before the top is lowered, thus preventing
the polyurethane adherence to the top. Thus, each layer forms a
closable support structure.
The expandable polyurethane creates pressure during
expansion with the top, bottom, and side supports containing the
pressure thus controlling the density of the second cast reproduction.
The cured density ranges from 5 lbs. per cubic feet to 25 lbs. per
cubic feet. As is well known in the art, if the castable material has a
large expansion the material will generate more pressure and thus,
more resistant pressure is required to accomplish the cure density
desired. Thus, closable support structure may have a means to resist
the required pressure during the cure.
FIG. 28, is a side view of the rack shelves being loaded from
station 26. After a particular mold is cured, it is removed to station 30.
FIG. 29 illustrates the press 14 with the pneumatic mechanism
16 expanded to close the top onto the mold during the cure.
FIGS. 29 and 30 show the press 14 with FIG. 14 showing the
deflated pneumatic mechanism 16.
FIG. 31 shows the pneumatic mechanism 16 inflated and thus,
closing the top onto the mold 8.
The FIGS 3, 7, 18, 24, 32, 33 and 34 illustrates the
manufactured articles in various shapes. The FIG. 32 illustrates the
fagade that may be used to give the appearance of a true stone wall.
The previous machine apparatus for continuous molding, by
using a conveyor, works well for large sheets. For smaller sheets, or
reproduction of odd shapes or composite shapes, the alternate
methods described and apparatus works very well.
In another embodiment of the apparatus, "low-rise" foam or
non-expandable castable material is used. A type of low-rise
polyurethane from Urethane Technologies Corp., Part No. UTC-6036-
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15c, is preferred. Alternatively, castable material that does not
expand can be used as illustrated herein. By using a low-rise, or non-
expandable, castable material there are advantages in that the
closable support structure may be merely a top placed over the mold.
The described low-rise castable material, with a density of
approximately 15 pounds per cubic foot, or non-expansive castable
material with good cast capability at low containment pressure allows
for a less rigid closable support structure. If side and bottom support
is desired, the closable support structure may be of material, such as
cardboard, composites, wood, plastic or other similar material.
In this embodiment, the only pressure applied to the mold is
due to closing the top onto the mold that is filled or that beomes filled
by the low-rise expansion. The method allows the cast article to be of
more complex shapes. These shapes may include rounded, sculpted,
or multi-faceted, shapes. If used with medium to high pressure, a
closable support structure for such shapes necessitates restricting the
pressures in all directions. Such pressure containment is a complex
requirement, making the apparatus very expensive and the process
difficult. With low or no-rise castable material only a very small
resistance to the expansion pressures, in the case of expansible
castable material, or the pressure of closing the top on non-
expansible castable material is necessary. Only enough pressure to
make sure the castable material fills the voids in the mold is needed.
The apparatus to accomplish the method and the steps of the
method using low or no-rise castable material are illustrated by FIG.
34 thru 47. The method and apparatus of the previous embodiments
are the same up to the casting of the cast article wherein the following
methods and apparatus may be used. In some circumstances the
casting of the master reproduction may use the following procedures if
the castable material for the master reproduction is of a low-rise or no-
rise type.
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FIG. 34 illustrates a closable structure 50 with a top 52, sides
56, latches 54, vents 58 and a protrusion area 60 in the top that
extends into the mold cavity with the top closed as illustrated in FIG.
35.
FIGS. 36 and 37, illustrate a side view from line 36-36 in FIG.
35. The mold 55 is supported by sides 56 and bottom 57. The top 52
is held on top of the mold by latch 54. The castable material 62, such
as the low-rise expansible polyurethane is placed in the mold cavity
before the top is closed. The protrusion area 60 extends into the
mold cavity.
In FIG. 37, the castable material during expansion fills the mold
cavity and exits the vents 58 after filling the mold cavity. In use of
castable material that does not expand, the mold cavity is filled so that
upon closure of the top 52 there is enough extra castable material to
be forced to exit by way of the vents 58, thus insuring that all voids in
the mold have been filled. The protrusion area 60 keeps the castable
material 62 from filling this area, thus creating a hollow area 64 in the
cast article 63 illustrated in FIGS. 38 and 39. The hollow area 64 is
used to save on material, to lessen the weight of the cast article 63
and may be used as a means of mounting the cast article. An inert
layer can also be applied between the top and the castable material if
adhesion is a problem.
The advantage of a hollow 64 is greater if the cast article 63
has a large volume. FIGS. 40-44 illustrate an example. The cast
article 63 is illustrated in FIG. 43 after it is removed from the mold
showing the hollow 64 formed by the protrusion area 60 of FIG. 42.
Again, if the castable material does not expand, the fill of the mold is
to the level that forces the excess castable material to exit the vents
58.
Because the mold 55 and cast article 63 must be removed
from any closable support structure 50 in order to remove the mold 55
from the cast article 63, the side 56 may need to be openable, such
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as shown in FIG. 44. This allows the removal of the mold and cast
article to then allow the removal of the cast article 63.
Where the cast article 63 is relatively flat there may be little
advantage to a hollow 64. In these circumstances, the top may not
have a protrusion area 60. In FIGS. 45-47, the top 52 is without any
protrusion. The vents 58 may be in any location on the top.
The castable material that exits the vents 58 will form mounting
aids such as ribs 66 in FIG. 47 when the cast material hardens.
These ribs may be removed or trimmed to a particular configuration
for mounting. One example of using the ribs 66 as a mounting aid is
in circumstances of mounting the cast article 63 against a flat
construction wall 68 as seen in side view in FIG. 48. The ribs 66 act
as spacers to keep the back side of the cast article 63 separated from
the construction wall 68. This has advantages in that moisture is not
trapped in this area, as the spacing allows for drainage and the
escape of any moisture. This helps to prevent mold and rot in walls
using these methods.
Materials
Several different types of materials are required to carry out the
invention described herein. Generally speaking, applicant's principal
required materials include: (1) those material(s) from which the cast
reproductions and the cast articles are made, (2) those material(s)
from which the molds are made and (3) those materials from which
the coloring agents are made. Various materials within these three
groups may be selected depending upon whether an original article to
be replicated is a manmade object (e.g., the surface of a wall
constructed from an array of bricks or stones, a carved item, such as
a decoratively carved panel or a machined object, such as a mold
component) or an object found in nature (e.g., a stone having a
surface that one desires to replicate).
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The materials from which applicant's master reproductions and
or cast articles are made preferably will be those thermoset polymers
(thermoset resins) that produce extremely hard, rigid items having the
mechanical strength and dimensional stability required of a given
master reproduction and/or cast article. Most preferably, the
thermoset polymer(s) selected also should be able to accept pigment
coloration in general and metal oxide pigment coloration in particular
(especially during a thermoset polymer curing process). Some of the
more preferred thermoset polymers for the practice of this invention
will include, but not be limited to: (1) urethanes, (2) phenolics, (3)
epoxies, (4) alkyds, (5) allylics, (6) aminos (melamine and urea), (7)
polyesters and (8) silicones. More specific thermosetting resin
materials that may be especially preferred for the practice of this
invention may include, but by no means be limited to: (1) polyether
polyurethane, (2) polyester polyurethane, (3) polyvinylchloride, (4)
polycarbonate, (5) polypropylene and (6) epoxy resin. Those skilled in
this art also will appreciate that almost all commercially available
thermoset polymers contain various additives. Such additives often
include catalytic agents, stabilizers, fillers, colors, plasticizers, flame
retardants, blowing agents, cross-linking agents and other more
specialized agents, such as ultraviolet light inhibitors and fungicidal
agents.
Again, the polyurethane materials most preferred for the
practice of this invention are those rigid polyurethane materials whose
ingredients are made and/or sold by Urethane Technologies
Corporation of Newburgh, New York under their designation "UTC-
6022-7.5FR". Their particular ingredient system is provided in two
components: Part A and Part B. To the best of applicant's knowledge,
Part A is a resin component containing polyols, blowing agents,
catalytic agents and having a viscosity of 150-350 cps at 77 F and a
specific gravity of 1.22 to 1.24 at 77 F. Part B is a polyisocyanate
component containing polymethylene, polyphenyl, isocyanate and
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having a viscosity of 1000 to 1200 cps and a specific gravity of 1.10 at
77 F. When appropriately mixed, and dispensed (e.g., by casting,
spraying, etc.) these two main ingredients produce a cured
polyurethane material having a density that ranges from about 5
pounds per cubic feet to about 25 pounds per cubic feet. The
preferred mixing ratio of component A (UTC-6022-7.5 FRA) to
component B (UTC-6022-7.5 FRB) is about 1:1 by weight. The
reactivities of these ingredients, at 77 F, are as follows: (1) cream
time 48-52 seconds, (2) string gel time 1 minute to 1 minute and 20
seconds, (3) rise time 4 minutes and 5 seconds to 4 minutes and 25
seconds, free rise core density 7.0-7.5 pounds/ft3 and mold dwell time
8 to 9 minutes. These two components can be dispensed (e.g., by a
hand, mixing gun, etc.) and reacted (e.g., at temperatures of 60-
250 F) in ways known to those skilled in this art.
In certain somewhat less preferred embodiments of this
invention, ceramic materials can be employed to make a first casting
(e.g., to make a master reproduction) and/or a second casting (e.g.,
cast article). It also should be noted that such firt castings (and in
some cases even a second casting) can be made of non-polymeric
materials such as ceramic materials, clays, plaster of Paris and the
like. Those skilled in this art will also appreciate that the most
essential ingredient in a ceramic material is clay (a hydrated
compound of aluminum and silicon H2 AI2 Si2 09, but also containing
relatively small amounts of various other compositions, such as ferric
oxide Fe203, silica Si02, calcium carbonate CaCo3). Other
ingredients commonly found in clays include feldspar, quartz and
dolomite. Be that as it may, one of the points to be made here is that
the first and/or second materials (e.g., thermosetting polymers,
ceramic materials, metals, etc.) that are respectively placed in the first
and/or second mold should be castable materials that are capable of
faithfully replicating the details of the surface of the original object and
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then curing (or drying or cooling) to form a solid, hard material that
also faithfully replicates the details of the surface of the original object.
The materials from which the first and/or second molds are
made can be flexible or inflexible end product materials (e.g., flexible
polymers, inflexible polymers, crystalline materials, metal castings and
the like). Most preferably, the polymeric materials employed for the
second molds will be those that produce flexible molds having the
mechanical strength, durability and flexibility needed for repeated use
of said second molds. The materials from which these second molds
are made also should: (1) be able to repeatedly withstand those
temperatures (e.g., temperatures up to about 3000 Fahrenheit) used
to create and/or cure the ingredients from which a given cast article is
made, (2) not chemically or mechanically bond with a given second
castable material (e.g., a thermosetting resin) being employed and (3)
not take up large quantities (e.g., more than 10% of its weight) of the
liquid used to create the coloring agent/liquid suspensions that may
be employed in the practice of this invention. Some of the more
preferred flexible mold materials are those polymers whose final forms
display the above noted qualities. Some of the more preferred mold-
making materials are of silicone based materials and especially so-
called "silicone rubbers." The most preferred silicone based material
for the practice of the herein disclosed invention is a silicone rubber
made and sold by Rhodia, VSI of Troy, New York as their "VI-SIL, V-
1065-S" product. Such silicone rubbers will preferably have a
durometer reading from about 15 to about 75.
Again, the materials from which the first mold is made also can
be flexible or inflexible end product materials (e.g., flexible polymers,
inflexible polymers, crystalline materials, metal castings and the like).
For example, they can be made from the same mold materials used
to make the preferred second molds (e.g., silicone rubber) or the
same "inflexible" polymer materials from which the end products are
made. Indeed, even non-polymeric materials, such as ceramic
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materials, plaster of Paris, or even metal castings could be employed.
The materials from which the first molds are made will not normally be
repeatedly used, or be used in conjunction with coloring agents.
Hence, there will generally be more latitude in selecting the material(s)
for making a given first mold relative to the material(s) that can be
selected for making a given second mold.
The preferred powdered coloring agent(s) for the practice of
this invention is (are) one or more inorganic pigment(s). Such
inorganic pigments may include, but are not limited to: (1) metal
oxides (e.g., oxides of iron, titanium, zinc, cobalt, chromium, etc.), (2)
metal powder suspensions (e.g., suspensions of gold, silver, tin,
copper, bronze, etc.), (3) earth colors (e.g., siennas, ochers, umbers,
etc.), (4) carbon black and/or mixtures thereof. Of these, the more
preferred inorganic pigments are metal oxides and/or carbonates, and
especially those of iron. These inorganic pigments are especially
efficacious in producing the coloring schemes displayed by certain
stones found in nature. They also are particularly effective in coloring
the surfaces of many different thermosetting resin materials.
Particularly preferred iron oxide compounds or compositions in this
regard are: (1) iron oxide, metallic brown (a naturally occurring earth,
principally ferric oxide, to which various extenders are normally
added), (2) iron oxide, yellow (hydrated ferric oxide, which is a
precipitated pigment of finer particle size and greater tinctorial
strength than the naturally occurring oxides, such as ocher, and
having particularly good lightfastness qualities), (3) iron oxide, black
(ferrosoferric oxide, ferroferric oxide, black rouge), (4) iron oxide, red
(e.g., pigments of ferric oxide commonly referred to as burnt sienna,
Indian red, red iron oxide, red oxide, Turkey red and rouge) and (5)
ferric oxide (ferric oxide, red, iron oxide, red iron trioxide and ferric
trioxide). A particularly preferred iron carbonate coloring agent is iron
"oxide", brown (iron carbonate, iron subcarbonate, which are usually
employed with ferric hydroxide and ferrous hydroxide in varying
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concentrations). Titanium dioxide is a particularly preferred coloring
agent when a white color is desired (a white color alone, or in a
coloring system needing a white color component). It also should be
appreciated that use of mixtures of any such pigments may be
particularly preferred for the practice of the herein disclosed invention,
especially when trying to imitate the colors of certain stones (e.g., so-
called sandstones) found in nature.
In certain other particularly preferred embodiments of this
invention, a powdered inorganic coloring agent ingredient will be the
main component of a coloring composition that further comprises
certain secondary ingredients. These secondary ingredients may be
pigment binders, ultraviolet light inhibitors, flame retardant agents,
anti-microbial agents, insect repellants, extenders and the like. If
used at all, these secondary ingredients will preferably comprise no
more than about 30% by weight of the powdered, inorganic coloring
agent ingredient/secondary ingredient composition. Coloring agent
compositions having from about 5% to about 20% (by weight) of such
secondary ingredients are somewhat more preferred. A particularly
preferred pigment binder or film-forming ingredient for creating
applicant's powdered, inorganic coloring agent/secondary ingredient
coloring formulations will be binder materials comprised of mixtures of
silicone dioxide (30-70% by weight of the binder mixture) and
polytetrafluoroethylene (30-70% by weight of the binder mixture).
Applicant especially prefers those pigment binders marketed by
Development Associates, Inc. of North Kingstown, Rhode Island
under their product name "Z-8261 ".
Suitable ultraviolet absorbers for the practice of this invention
may include, but are not limited to, benzophenones, benzotriazoles,
substituted acrylonitriles and phenol-nickel complexes. Suitable
flame-retarding agents may include, but are not limited to, chlorinated
organic compounds, such as chlorendic anhydride, alumina
trahydrate, ammonium sulfamate, zinc borate and various organic
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phosphates and phosphonates. Suitable fungicides may include, but
are not limited to copper oxychloride, copper naphthenate and
dithiocarbamate. Most preferably, such ultraviolet absorbers, flame-
retarding agents, fungicides and the like will not, in total, constitute
more than about 8% by weight of the total weight of the end product.
In yet another highly preferred embodiment of this invention,
the coloring agents are dispensed into a second flexible mold cavity in
a powdered form. For example, such powders could be simply
sprinkled, brushed, blown, etc., in their powdered forms, into the
cavity or cavities of the second mold prior to filling said mold with the
second castable (e.g., a thermosetting resin material). In the most
preferred embodiments of this invention, however, the powdered
coloring agent(s) become a component of a coloring agent
suspension that is placed in, or created in, the cavity or cavities of the
second mold before the second castable material(s) is (are) poured,
injected, blown, etc. into said cavity or cavities. That is to say that, in
this highly preferred embodiment, before the second castable
material(s) is (are) poured, injected, sprayed, etc. into the second
mold cavities, the powdered coloring agent becomes a component of
a two (or more) phase coloring system. One phase is comprised of
the particles of the powdered coloring agent(s) and their associated
secondary ingredients (if any) and a second phase is comprised of a
liquid suitable for creating a powdered coloring agent/liquid
suspension used to impart the pigment color(s) to the mold side
surface of the cast article (i.e., to the "face side" of the end product of
this production method). In a less preferred, but still operable
alternative, such a powdered coloring agent/liquid suspension can be
pre-formulated and then introduced into (e.g., by spraying, brushing,
etc.) the cavities of the second mold. Such a suspension also could
be an added ingredient of an entire composition (e.g.,
polyurethane/powdered coloring agent/liquid suspension) from which
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a second thermosetting resin(s) material(s) is (are) made in a
thermosetting reaction.
In another particularly preferred embodiment of this invention,
the powdered coloring agent/liquid suspension will be created in the
following manner. First, one or more coloring agents (in powdered
form) are introduced (e.g., by sprinkling, spraying, brushing, etc.) into
one or more cavities of a second, flexible polymer, mold. An
appropriate suspension creating liquid is then sprayed over the
powdered inorganic pigments (in the alternative, the liquid could be
sprayed into the cavities first and the powdered coloring agent added
thereafter). These two materials are then mixed (preferably by brush
stroke action) to form the desired powdered coloring agent/liquid
suspension ("the resulting suspension"). The resulting suspension
will generally have the consistency of wet paint or stain. In some of
the most preferred embodiments of this invention the brushing action
(e.g., by human hand) should be sufficient to create the suspension,
but not sufficient enough to create a thoroughly homogeneous
pigment/liquid composition. This lack of homogeneity serves to create
regions (e.g., streaks) having different colors and this quality generally
tends to give the resulting cast reproduction a more "natural" (e.g.,
stone-like) appearance. That is to say that products colored in this
way tend to better replicate the colors, texture, and visual appearance
of certain natural objects such as certain stones.
The liquid(s) used to create the coloring agent/liquid
suspension is (are) preferably polar solvents (e.g., an alcohol, such as
ethyl alcohol, methyl alcohol and the like, water and/or weak acids).
Most preferably the polar solvent(s) employed is (are) not corrosive
toward, or readily absorbed by, the material (e.g., silicone) from which
the second mold is made. In the case of using iron oxide type
inorganic pigments in the practice of this invention, denatured alcohol
is a particularly preferred liquid for the creation of applicant's
powdered coloring agent/liquid suspensions.
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Those skilled in this art will appreciate that the embodiments
discussed above are exemplary of the present invention. They are
not, however, intended to limit the scope of the claims of this patent
application. Many other substances and techniques, different from
those discussed above, can be used. That is to say that all changes
and modifications that come within the spirit of the present invention
are intended to be protected by the following patent claims.
The embodiments discussed above are merely exemplary of
the invention of this application. They are not intended to limit the
scope of the claims of this application in any respect. Many
substances and techniques different from those discussed above can
be used in practicing the invention of the application, and a wide
range of techniques can be used for that purpose. Only preferred
embodiments and minor variants thereof have been shown and
described above, and all changes and modifications that come within
the spirit of the invention are intended to be protected.
