Note: Descriptions are shown in the official language in which they were submitted.
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FILLER FOR MOLDED ARTICLES
FIELD OF THE INVENTION
The present inven-tion relates to filler
materials for curable molded and cast articles and
processes for producing such filler materials. In
particular, the invention relates to filler materials for
curable molded and cast articles where certain of the
components of the filler material are produced by recycling
otherwise unusable materials.
BACKGROUND OF THE INVENTION
It is common in the art to provide various
filler materials for molded and cast articles produced with
a curable base material and in particular such articles
made with synthetic resins as the curable base material.
Such filler materials are generally used for economic
reasons as the curable base material is generally very
expensive or to improve certain of the characteristics of
the products either physical characteristics as for example
strength, rigidity, density, impact or heat resistance or
shrinkage or aesthetic characteristics in terms of
coloring, marbleizing or other treatments.
Filler materials are commonly employed in the
production of various types of artificial stones wherein
the filler material is mixad with a curable synthetic
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resin. A pigment is partially mixed into the resin and
filler so the streaks of filler and pigment appear in the
final molded object giving the molded object the appearance
of the natural stone as for example marble, onyx, soap
stone or other stone. Traditionally, the fillers employed
have been various inorganic substances such as aluminum
hydroxide, alumina, calcium carbonate and various natural
stone powders and aggregates. These fillers are
traditionally incorporated into a resin such as polyester
resin, epoxy resin or acrylic resin, in particular methyl
methacrylate (MMA). Upon mixing, the mixture can be molded
to form sink basins, counter tops, or other architectural
structures and various objects of art.
When utilizing filler material with synthetic
resins as the curable base material, problems of
miscibility, adhesion, etc. are present due to the
substantial differences in properties between the inorganic
filler and the organic resin which may result in non-
uniform dispersion of the filler in the resin material.
There have been attempts to develop organic based filler
materials which will overcome some of these difficulties.
One such organic based filler material is described in for
example U.S. Patent No. 4,678,819. Others have attempted
to overcome the difficulties by providing silicate or
silane based filler materials such as described in U.S.
Patent Nos. 4,643,921 and 4,771,095. These filler
materials, while overcominq some of the difficulties,
utilize high value prime ingredients for the filler and
hence increase the cost of production of the final molded
or cast article.
Numerous articles made from plastic, glass and
metal are produced each year and while attempts to provide
for reuse or recycling of the material of such articles
have been instituted in many communities, there are still a
number of such articles which are at present not
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recyclable. For example, at the present time, many tons of
articles produced from polystyrene are discarded requiring
the provision of suitable land fill sites for their
disposal.
Post-consumer plastic articles in a variety of
high density and low density polyethylene as well as pre-
consumer prime waste are now being recycled. During the
process of shredding, meltiny and forming the waste plastic
into pellets that can be re-used by the plastics industry,
tons of mixed polyethylene are also produced. This mixed
polyethylene cannot be used by the majority of the plastics
manufacturers for a variety of reasons, for example, the
typical machines and tools used by the industry have been
lS geared to handle polymers of a certain density and in
pellet form for ease, convenience and economy. The mixed
polyethylene is composed of a mixture of polyethylene
polymers with different melting temperatures and thus is
not suitable for re-cycling at the present time.
Another example of the above situation is found
in the recycling of metals from used wire and cables
encased in a plastic covering. Again tons of plastic
fluff, both polyethylene and polyvinylchloride, are
occasionally produced during the process of extracting the
metals and until now most of this fluff has been disposed
of in land fill sites.
Many large glass companies are recycling only
the sorted used glass articles which have been collected
from consumers. However if various types of glass are
mixed and cannot be sorted, it is not possible at present
to recycle the mixed glass because their equipment cannot
handle the variation in the melting temperatures of the
mixed glass.
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Processes which could utilize such articles as
the raw materials for the processes would have access to a
potentially inexpensive source of raw material.
Additionally, the ability to recycle such articles would
result in significant savings to the environment.
SUMMARY OF THE INVENTION
The present invention is directed to a powdered
filler for use in curable molded or cast articles. The
filler comprises one or more particulate components to be
incorporated into the molded or cast article, the
particulate components being encapsulated by polystyrene.
In an aspect of the invention, a process for
producing the filler for use with curable molded or cast
articles i5 provided. The process comprises dissolving
polystyrene in a suitable solvent, mixing into the
dissolved polystyrene one or more particulate components to
be incorporated into the molded or cast article, and drying
the mixture, whereby the particulate components are
encapsulated by the polystyrene.
In another aspect of the invention a molded or
cast article is provided, the molded or cast article
comprising a curable base material having incorporated
therein the powdered filler.
In yet another aspect of the invention a process
for producing molded article is provided, the process
comprising adding the filler to a curable base material in
a suitable mold to produce a molded or cast article.
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DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
The present invention provides for a filler for
use in producing curable molded and cast articles. The
filler comprises particulate components coated or
encapsulated by polysty.ene. The filler of the present
invention provides for the even distribution during casting
or molding processes of components which may be
incompatible in the base material. Thus, for example,
polyethylene which would normally float to the surface
during the molding or casting process is maintained evenly
distributed throughout the article by coating or
encapsulating in the polystyrene. Similarly, powdered iron
which would normally sink to the bottom is maintained
evenly distributed. Additionally, by encapsulating the
particulate components in the polystyrene, the polystyrene
may have pigment added to it to mask the intrinsic color of
the particulate component. In this way the particulate
component for the filler can be selected based upon desired
characteristics independent of the aesthetic qualities of
the particulate component.
The first step in the production of the fillers
of the present invention is dissolving polystyrene in a
suitable solvent. The suitable solvent for dissolving the
polystyrene can be any of the solvents commonly known to
dissolve same. The solvent may be selected from the group
consisting of terpenes such as d-limonene, pinene or
turpentine, styrene, carbon tetrachloride, methylethyl
ketone, dioxane, butyl acetate, ethylene chloride, benzene
or pyridine. Most preferably, because of the ease of
handling the solvent safely with minimal risk to the
operator or the environment, the solvent is a pure
turpentine. It has been found that the more expensive
brands of turpentine containing mineral spirits will not
totally dissolve the polystyrene and therefore, the less
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expensive pure turpentine has been found to be most
suitable.
The polystyrene is preferably dissolved at a
concentration of 15 to 45 g of polystyrene per 100 ml of
suitable solvent, most pre~erably, 20 to 40 g of
polystyrene per 100 ml of solvent.
Depending upon the type of polystyrene being
used, certain precautions should be taken if dissolving
previously foamed or expanded polystyrene. Some expanded
or foamed polystyrene is produced using gases such as forms
of pentane or hexane which remain associated with the
polystyrene. As such gasses may be toxic, suitable
precautions in terms of venting must be taken. The
behaviour of the gasses and the stage of the process where
such precautions are necessary are dependent upon the
solvent being utilized. Some solvents release the gasses
immediately upon dissolving the polystyrene. Other solvents
such as turpentine appear to dissolve the gasses whereby
they are not released until such time as the dissolved
polystyrene is dried, at which time the gasses must be
vented and recovered.
The dissolved polystyrene may then be used to
produce the fillers of the present invention. If desired
the dissolved polystyrene can also be recycled to yield
polystyrene alone. This recycling may be accomplished by
simply drying the dissolved polystyrene into sheets or the
dissolved polystyrene may be processed using a solvent
extractor, an extruder and cutter to produce polystyrene
pellets. During the solvent extraction step the solvent
may be recovered utili~ing for example a chiller or solvent
recoverer. In this way the solvent may be recycled for
further use in the process. During the processes of
recycling the dissolved polystyrene where the polystyrene
is previously foamed or expanded material, it may also be
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possible to recover the gasses that were utilized in the
production of the foamed or expanded polystyrene. The
gasses may be recovered by extraction during either the
dissolving proc~ss or the solvent extraction process
depending upon the solvent being utilized for dissolving
the polystyrene. Such gasses, if properly recovered, can
then be reutilized with the polystyrene to produce foamed
or expanded polystyrene beads.
The fillers of the present invention which are
used for curable molded or cast articles are produced by
mixing into the dissolved polystyrene prepared as above,
the particulate components of the filler, then drying the
mixture, thereby encapsulating the particulate components
in polystyrene. The particulate components are generally
any inert components which can be utilized as a filler in
the curable molded or cast article. By the term inert, it
is meant that the particulate component is not generally
reactive with the polystyrene or solvent utilized for
dissolving polystyrene as for example, the component is not
soluble in the solvent. Such particulate components may
include crushed glass, powdered glass, powdered
thermoplastics such as polyethylene or polyvinylchloride,
powdered stone, iron powder, clay, gypsum, mica, concrete,
paper, urea, etc. Other optional additives such as
pigments, fire retardant materials and the like may be
added to the mixture either prior to the drying or to the
powdered mixture produced from the drying step depending
upon the nature of the optional additives. Suitable such
additives would be those additives generally utilized in
the production of curable molded or cast articles.
Preferably the additives are added prior to drying,
however, depending upon the effect desired, pigments can be
added at any stage in the process of producing the filler
or the molded article.
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In order to provide Eor a very economic process
for producing the filler, the polystyrene and particulate
components for example, pol~ethylene, polyvinylchloride,
powdered stone, iron powder, gypsum, mica, concrete, paper,
urea and glass are preferably produced from recycling of
previously used articles. The polystyrene may be recycled
from previously formed, high density polystyrene articles
such as disposable cutlery or from previously foamed or
expanded polystyrene articles such as for example beverage
containers, insulation, packaging and the like. Preferably
the polystyrene is recycled from expanded or foamed
polystyrene articles. The polystyrene is bro~en down if
necessary and then added to the suitable solvent until
dissolved. Similarly, the polyethylene, polyvinylchloride,
glass and other particulate components may be recycled from
previously used articles. As the process of the present
invention does not require the use of heat the particulate
components such as the polyethylene and glass can be
previously unusable mixed polyethylene and glass.
The particulate components are ground up to
produce aggregates or powders prior to being added to the
dissolved polystyrene. For powders the particulate
components are ground or milled to preferably have an
average particle size of 3 to 300 mesh, more preferably 10
to 200 mesh, most preferable 30 to 100 mesh (U.S.
Standard). The particle size of the particulate component
is selected based upon the desired effect in the final
article and upon the porosity of the component amongst
other factors. Thus for more porous materials such as
limestone or clay, larger particle sizes are preferred
while for less porous materials such as polyethylene or
polyvinylchloride, smaller particle sizes are preferable.
Flame retardants such as aluminum trihydrate or
antimony compounds, preferably aluminum trihydrate may be
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added depending upon the concentration of such materials
already present in the recycled material.
Pigments may be added to the liquid filler,
powdered filler, or to the curable base material depending
upon the presence of pigments already in the article from
which the polystyrene was produced and the desired final
article in terms of color and effect. The pigment can be
any of those compounds which are typically used in the
production of curable molded or cast articles or any of the
pigments that are typically used in the production of paint
as for example various titanium, chrome, cadmium, iron,
strontium and barium compounds, amongst others. If it is
desired to have a finished article with an opaque color
effect to the filler then the pigment is added to the
dissolved polystyrene prior to mixing in the particulate
components and drying. In this way the pigment becomes
incorporated into the polystyrene encapsulating the
particulate component and masks the intrinsic color of the
particulate components. If no pigment is present in the
polystyrene article from which the polystyrene was produced
nor is added to the polystyrene solution during the
encapsulation of the particulate, the filler will ha~e
particulate components encapsulated by translucent
polystyrene. In this way the intrinsic color of the
particulate components of the filler lends a diffused or
translucent color to the final article. Color may also be
added to clear base materials for articles where a uniform
opaque color is desired. The color in the base material
will mask the intrinsic colors of the filler materials
which will then be selected on their desired physical
properties other than aesthetic effect.
The fillers oE the present invention can be
utilized with any suitable curable base material such as
for example curable synthetic resins, cements or concretes.
Amongst the curable synthetic resins that can be utilized
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are urethanes, polyesters, epoxy, and acrylic esters such
as methyl methacrylate. The selection of the suitable
curable base material will be dependent upon the desired
final product.
The filler preferably comprises 10 to 35% by
volume of the dissolved polystyrene with the remainder
being the particulate component, more preferably the filler
contains 17 to 25% dissolved polystyrene with the remainder
particulate components, most preferably 20% dissolved
polystyrene with the remainder the particulate components.
The concentration of polystyrene in the filler material
will be selected depending upon the particulate components
utilized in the filler material and the desired effect in
lS the final molded or cast article. For example, with
particulate components, it is most preferred to use 20%
polystyrene to 80% of the particulate component materials,
all by volume. For very porous materials such as clay, up
to 25% polystyrene is preferred and for less porous
materials such as plastics, for example, polyvinylchloride
or polyethylene, 17 to 18% polystyrene is preferred.
For certain applications the filler may be used
in the liquid state prior to drying, however for ease of
handling and to provide flexibility in use it is preferred
to use the filler in the dried, powdered state.
To produce the dried, powdered filler material,
the above ingredients are mixed together, dried and then
powdered. The filler may be dried by any of the methods
commonly employed in the art such as for example vacuum and
air drying, spray casting, etc. The method of drying of
the filler will be dependent upon the solvent being
utilized and such factors as whether previously foamed
polystyrene was utilized and whether the gasses used in the
production of the previously foamed polystyrene have been
dissolved in the solvent. With turpentine as a solvent it
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is preferred to vacuum dry the filler and to pass the
exhaust from the vacuurn dryer through a solvent recoverer
to recover the turpentine and gasses. Alternatively, the
filler may be dried by air drying with proper venting for
the escaping gasses being provided. The dried filler
material owing to the encapsulation of the particulate
components by the polystyrene is a very granular material.
This granular material may be used as is or may be further
processed using standard techniques such as milling,
grinding or pulverizing to produce powders of various
particle sizes. Thus with some processing of the granular
material the granules can be reduced slightly in particle
size. By further processing the granules can be reduced to
a medium or fine powder. However, in order to maintain the
encapsulation of the particulate components the powdering
of the filler material should be such to provide average
particle sizes at least the same as or greater than the
average particle sizes of the particulate components
utilized to produce the filler. By processing beyond this
point some of the polystyrene encapsulating the particulate
components may be stripped from the particulate components.
The filler material may be produced having a
single particulate component or fillers having multiple
particulate components may also be produced. It is
preferable to produce fillers having a single particulate
component as less grinding is required to powder the filler
owing to the relative homogeneity of the filler material.
Additionally, various single component filler may be
blended depending upon the particulate component and the
pigmentation of the fillers to produce any desired effect
in the final molded or cast article.
In preferred embodiments of multiple component
fillers for use with curable plast:ic resins, the filler
comprises 15 to 35% by volume polystyrene, 10 to 50% by
volume dissolved polyethylene and 10 to 70% by volume
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powdered glass. More preferably, the filler contains 20 to
25% dissolved polystyrene, 15 to 35% polyethylene and 45 to
~0% powdered glass. Most preferably, the filler contains
20% polystyrene, 25% polyethylene and 55% powdered glass.
The preferred composition will depend on the viscosity of
the base material used in molding or casting the finished
article and the desired effect in the finished article.
If aluminum trihydrate is added to the mixture
as a flame retardant, it is preferably added in the range
to 3 to 10% of the mixture most preferably, 5% of the
mixture. When adding the aluminum trihydrate it is
preferable to maintain the levels of polystyrene and adjust
the proportion of particulate components to compensate for
the aluminum trihydrate. Thus, in the most preferred
mixture 20% polystyrene, 75% particulate components, and 5%
aluminum trihydrate are mixed, dried and powdered in a ball
mill or grinder.
The filler materials either in liquid or powder
form are added to a suitable curable base material for
molding or casting into the desired shape. The curable
base material is preferably a thermose-tting resin to
provide a finished article not affected by heat. Such
thermosetting resins may include for example urethanes,
acrylic resins such as methyl methacrylate, polyester
resins or epoxy preferably polyester or epoxy resins. With
liquid filler material, it is preferable to add the liquid
material to the catalyzed resin. The mixture is then
degassed, and thereafter the mixture is placed into the
mold. Accelerators or further catalysts may be added to
the resin at the time of mixing with the filler if desired.
Use of pressure molding techniques also tends to accelerate
the curing of the resin.
In mixing together the liquid flller and the
epoxy or polyester resin it has been found that the mixing
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operation is made easier if the resin is warmed slightly -to
a temperature of between abou-t 25 and 35 C prior to
mixing while the liquid filler is maintained at room
temperature. Warming of the resin also allows higher
ratios of filler to be used and reduces the the incidence
of bubbling in the casting and curing of the final article.
For the powdered filler material, the powder in
suitable quantities is added to the curable resin, a
suitable catalyst is added, the mixture degassed and
thereafter placed into a mold. It has been found that when
utilizing epoxy resins an accelerator and/or pressure
molding techniques are preferably used to shorten curing
times.
The proportion of the filler material to the
base material is selected depending upon the desired
characteristics of the final molded or cast article, in
particular the hardness of the article desired, the
composition of the fi]ler material, the type and viscosity
of the base material being used and the desired viscosity
of the final mixture. The ratios can vary anywhere from 20
to 80% of filler material and 80 to 20% of base material.
Mixtures high in concentration of filler material
containing polyethylene, e.g., 70 to 80% of filler material
containing 20% or more polyethylene tend to produce a
softer article. Mixtures having higher ratios of base
material, e g., 40 to 60% of the filler material, 60 to 40%
of the base material produce a much harder article which is
suitable for producing decorative tiles, artificial marble
counter tops and decorative art pieces. The most preferred
ratio is 55% to 60% of filler material to 45% to 40% of
base material.
For producing molded or cast articles having a
marbleized effect, mixtures of the fillers and in
particular mixtures of liquid and powdered filler may be
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utilized with the curable base material. For example, a
mixture containing pigmented liquid dissolved polystyrene
in a curable base material is gently mixed into a curable
base material containing a powdered filler. Preferably the
cura~le base materials are thermosetting resins such as
polyester or epoxy. The molded or cast article produced
imitates very closely the effects of veined marble or onyx.
The mix-ture of the powdered filler material and
the resin may also be utilized for spray coating, in
particular spray coating of cements, concretes and gypsums.
The molded or cast articles can be produced by
any of the standard molding or casting techniques. For
curable resins and in particular thermosetting resins, cast
molding, vacuum and pressure molding may be used, depending
upon the final desired article to be produced.
The present invention will be illustrated in the
following non-limiting examples:
EXAMPLE 1
35 g of used foamed polystyrene coffee cups were
dissolved in 150 ml of pure turpentine to produce a mixture
having a final volume of 175 ml. To this mixture was added -
245 ml of fluffed recycled polyethylene, 35 ml of alumina
trihydrate, 280 ml of powdered glass to produce a liquid
filler mixture.
EXAMPLE 2
50 g of used previously foamed polystyrene were
dissolved in 150 ml of turpentine. To the mixture 225 ml
of fluffed recycled polyethylene, 45 ml of alumina
trihydrate, 450 ml of powdered glass was added, the mixture
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mixed thoroughly, vacuumed to dry and then f:Lnally powdered
in a ball mill.
EXAMPLE 3
200 ml of the liquid filler mixture produced in
accordance with Example 1, was added gradually with
stirring to 200 ml of warm catalyzed polyester resin, the
mixture degassed under vacuum and poured into a casting
mold for producing tiles measuring 2 inches by 2 inches by
1/4 inch. The tiles produced had a hard surface with a
feel similar to that of ceramic tile and did not have the
plastic feel usually associated with polyester resins.
EXAMPLES 4 TO 7
Example 3 was repeated using varying ratios of
the components of the liquid filler material and varying
ratios of filler to polyester resin and thereafter casting
into the tiles. The results of the examples are shown in
the following table:
Example liquid filler polyester appearance of
material resin the tile
4 (50% vol PS -smooth hard stone
50% vol PG) like surface
160 ml 240 ml -miscible during
processing
~as in 4) -as above but less
240 ml 160 ml brittle
35 6 (25% vol PS -as above but less
30~ vol PE brittle and more
45% vol PG) resilient not
160 ml 240 ml flexible
40 7 (as in 6) -as above but more
240 ml 160 ml difficult to pour
into open cast
molds that are
intricate
PS - polystyrene PG - powdered glass PE - polyethylene
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EXAMPLE 8
100 ml of a powdered filler material produced in
accordance with Example 2 was added to 100 ml of a slightly
warmed mixture of parts A and B of epoxy resin and
accelerator. The mixture was degassed and poured into a
casting mold to produced tiles having dimensions 2 inches
by 2 inches by 1/4 inch. The tiles had a hard surface.
EXAMPLES 9 TO 11
Example 8 was repeated using varying ratios of
powdered filler material to epoxy resin and thereafter
casting into the tiles. The results of the examples are
shown in the following table:
Example powdered filler epoxy appearance of
material resin the tile
9 (25% vol PS -rubbery, pliable
45% vol PE soft flexible tile
30% vol PG)
100 ml 100 ml
(50% vol PS -hard but still
25% vol PE slightly flexible
25% vol PG) resilient
100 ml 100 ml -plastic feel
11 (20% vol PS -hard almost
15% vol PE brittle
65% vol PG) -surface abrasion
100 ml 100 ml resistant
-less plastic feel
PS - polystyrene PG - powdered glass PE - polyethylene
EXAMPLE 12
A cast artificial marble was produced as
follows: 125 ml of polyester resin was catalyzed using
approximately 12 drops of appropri.ate peroxide catalyst, 50
ml of liquid filler comprised of 30% dissolved polystyrene,
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30% powdered mixed polyethylene and 40% powdered mixed
glass was slowly added to the polyester mixture. The
filler as a result of the mixed polyethylene and mixed
glass had a black color which, upon mixing with the resin,
resulted in a clear resin mixture with black suspended
particles. Two aliquots of 5 ml of the polyester resin
liquid filler mixture were drawn, one of the aliquots was
colored with titanium white pigment, the other aliquot was
coloxed with yellow ochre pigment. All three of the above
mixtures were vacuumed briefly to degas. The pigmented
mixtures were added back to the base mixture, slightly
stirred to obtain the marbleizing effect and poured into an
open Room Temperature Vulcanizing (RTV) silicone mold.
EXAMPLE 13
125 ml of polyester was catalyzed using 12 drops
of appropriate catalyst, 100 ml of powdered filler
comprising 20% dissolved polystyrene, 5% alumina
trihydrate, 35% powdered polyethylene, 40% powdered glass
was slowly added to the polyester mixture which then took
upon a black coloration. Two 5 ml aliquots of the
polyester filler mixture were drawn, one aliquot was
colored with titanium white pigment and the o-ther aliquot
was colored with yellow ochre pigment. The above mixtures
were vacuumed and degassed and the pigment mixtures were
added back to the polyester filler mixture, slightly
stirred to create a marbleizing effect, and slowly poured
into an open RTV silicone mold.
EXAMPLE 14
90 ml of part A epoxy and 60 ml of part B epoxy
were warmed, mixed together and appro~imately 1.5 ml of
appropriate accelerator was added. 150 ml of a liquid
mixture comprising 25% dissolved polystyrene, 25% powdered
polyethylene and 50% powdered glass was mixed into the
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epoxy resin. A 10 ml aliquot was drawn to which was added
a titanium white pigment. A further 15 ml aliquot was
drawn to which was added a yellow ochre pigment. All three
of these mixtures were vacuumed to degas. The piqmented
mixtures were then added back to -the epoxy resin filler
mixture, the mixture slightly stirred to create a
marbleizing effect and then poured into an open RTV
silicone mold.
EXAMPLE 15
300 ml of epoxy mixture was prepared by mixing
180 ml part A and 125 ml of part B, 3 ml accelerator was
added and thereafter, 210 ml of powdered filler comprising
20% dissolved polystyrene, 5% alumina trihydrate, 35%
powdered polyethylene and 40% powdered glass was added. Two
15 ml aliquots were drawn into one of which was added
titanium white pigment and into the second aliquot yellow
ochre pigment was added. All three mixtures were vacuumed
to degas and the pigmented mixtures added back to the epoxy
and filler, the mixture slightly stirred to create a
marbleiæing effect and then poured into an open RTV
silicone mold.
EXAMPLE 16
165 g of previously foamed polystyrene was
dissolved in 450 ml of turpentine to produce a mixture
having a final volume of 600 ml. To separate lO0 ml
aliquots of the dissolved polystyrene, 400 ml of
polyethylene, iron powder, limestone powder, powdered
glass, polyvinylchloride or molding was added. To each of
the resulting mixture a cadmium yellow pigment was added,
the mixtures dried with proper venting and then powdered.
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EXAMPLE 17
165 g of foamed polystyrene was dissol~ed in 450
ml of turpentine to produce 600 ml of dissolved
5 polystyrene To separate 200 ml aliquots of the dissolved
polystyrene was added, 800 ml polyethylene; 400 ml
polyethylene and 400 ml limestone; or 200 ml limestone and
600 ml iron powder respectively. The resulting mixtures
were dried with proper venting and powdered to produce
10 light, medium and heavy fillers respectively. The fillers
were ground to a variety of si~es.
EXAMPLE 18
A marbleized article was produced as follows.
To 60 ml slightly warmed Part A of Epoxy, 65 ml of black
pigmented filler containing powdered glass prepared in
accordance with Example 16 was added, mixed and degassed.
To 55 ml of room temperature part B, 70 ml of black
pigmented filler containing powdered glass prepared in
accordance with Example 16 was added,mixed and degassed.
25 To 60 ml of warmed Part A, 65 ml of yellow pigmented filler
containing powdered glass prepared in accordance with
Example 16 was added, mixed and degassed.
To 55 ml of room temperature Part B, 70 ml of yellow
30 pigmented filler containing powdered glass prepared in
accordance with Example 16 was added, mixed and degassed.
To 60 ml of warmed Part A, 65 ml of white pigmented filler
containing powdered glass prepared in accordance with
35 Example 16 was added, mixed and degassed.
~:,. -, . . , ~ , : ;
.. . .
To 55 ml of room temperature Part B, 70 ml of white
pigmented filler containing powdered glass prepared in
accordance with Example 16 was added, mixed and degassed.
Each of the individually colored part A and part B
solutions were mixed together and degassed. The three
individual epoxies are gently mixed together and the
mixture gently poured into an RTV mold and cured in a
pressure pot to produce the marbleized piece.
It will now be seen how utilizing the filler
material of the present invention, molded articles having
the appearance and feel of natural stone can be produced
economically from heretofore unusable plastic materials
lS economically and with significant savings to the
environment.
Although various preferred embodiments of the
present invention have been described herein in detail, it
will be appreciated by those of skill in the art that
variations may be made thereto without departing from the
spirit of the invention or the scope of the appended
claims.
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