U.S. patent application number 13/372369 was filed with the patent office on 2013-06-13 for method and apparatus for extruding a coating upon a substrate surface.
The applicant listed for this patent is Richard B. Flora, Roderick Hughes, Gordon L. King, Kendall W. Prince. Invention is credited to Richard B. Flora, Roderick Hughes, Gordon L. King, Kendall W. Prince.
Application Number | 20130145985 13/372369 |
Document ID | / |
Family ID | 24065836 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130145985 |
Kind Code |
A1 |
Prince; Kendall W. ; et
al. |
June 13, 2013 |
METHOD AND APPARATUS FOR EXTRUDING A COATING UPON A SUBSTRATE
SURFACE
Abstract
A coating apparatus and method are disclosed that applies a
coating to a product in a uniform and controlled manner. The
coating apparatus comprises a feeding stage, an optional
pre-treatment stage, at least one coating stage and a finishing
stage. The coating stage(s) comprise a coating material feeder and
a coating device. The coating device includes an aperture
conforming to the perimeter of a substrate to be coated in a first
and second dimension. As the substrate passes through the aperture,
coating material is applied in a uniform and consistent layer. The
coating material also back fills minor surface imperfections and
blemishes on the substrate to achieve a consistent finish across
the whole area where coating material is applied.
Inventors: |
Prince; Kendall W.; (Mesa,
AZ) ; King; Gordon L.; (Mesa, AZ) ; Hughes;
Roderick; (Newport Beach, CA) ; Flora; Richard
B.; (Wabash, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Prince; Kendall W.
King; Gordon L.
Hughes; Roderick
Flora; Richard B. |
Mesa
Mesa
Newport Beach
Wabash |
AZ
AZ
CA
IN |
US
US
US
US |
|
|
Family ID: |
24065836 |
Appl. No.: |
13/372369 |
Filed: |
February 13, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
12123308 |
May 19, 2008 |
8113143 |
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13372369 |
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|
10723500 |
Nov 26, 2003 |
7374795 |
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12123308 |
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|
09518870 |
Mar 6, 2000 |
6660086 |
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10723500 |
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Current U.S.
Class: |
118/407 |
Current CPC
Class: |
B05C 3/12 20130101; B05C
3/00 20130101; B05C 3/005 20130101; B28B 11/044 20130101; B29C
48/12 20190201; B05C 11/1042 20130101; B29C 48/154 20190201; B28B
3/2636 20130101; B05D 1/265 20130101 |
Class at
Publication: |
118/407 |
International
Class: |
B05C 3/00 20060101
B05C003/00 |
Claims
1. An apparatus for applying a coating material to an outer surface
of a substrate, comprising: a die having a cavity and an aperture,
the aperture having a collection surface and interior wall
surfaces; a receiving channel in fluid communication with the
cavity of the die, the receiving channel collecting and delivering
the coating material to the cavity; and means for feeding the
substrate through the cavity and the aperture, wherein the coating
material within the cavity is applied to the outer surface of the
substrate.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/123,308, filed on May 19, 2008, entitled
"METHOD AND APPARATUS FOR EXTRUDING A COATING UPON A SUBSTRATE
SURFACE," which is a continuation of U.S. patent application Ser.
No. 10/723,500 (U.S. Pat. No. 7,374,795), filed on Nov. 26, 2003,
entitled "METHOD AND APPARATUS FOR EXTRUDING A COATING UPON A
SUBSTRATE SURFACE," which is a continuation of U.S. patent
application Ser. No. 09/518,870 (U.S. Pat. No. 6,660,086), filed on
Mar. 6, 2000, entitled "METHOD AND APPARATUS FOR EXTRUDING A
COATING UPON A SUBSTRATE SURFACE," all of which are incorporated
herein by reference.
BACKGROUND
[0002] The present invention relates generally to coating methods
and systems and, more specifically, the present invention relates
to a method and system for passing a substrate through a die that
applies a coating on the surface of the substrate in a controlled
manner.
[0003] Applying a coating substance to a substrate is well-known in
the art. In applying a coating substance to elements such as wood,
plastic, and metal, typically the coating substance is a paint that
is applied with a solvent as a carrying agent. This allows the
paint to coat the wood, plastic, or metal surface quickly and
efficiently. Unfortunately, the solvent must evaporate out of the
paint and the paint must dry before the surface can be handled.
[0004] An alternative method for applying a coating to a surface
includes applying an electrostatic charge to the surface of the
substrate, typically a metal, and then oppositely charging the
paint so that as it is blown against the surface of the object, the
opposite charges attract the paint to the surface. Once the paint
powder attaches to the surface via the electrostatic charge, the
object is heated in an oven to cure the paint for the final finish.
This incurs the steps of cleaning the substrate surface in order
for the paint to adhere to all portions of the surface, heating the
substrate to a sufficient enough temperature to melt the paint for
application, and finally cooling the substrate for handling.
[0005] A third method includes running the substrate via a conveyor
through a ribbon of coating material to coat the exposed surfaces.
The substrate is then inverted to coat the bottom surface as it
passes through the curtain of coating material again or in a second
stage. In this method, the coating material is a liquid, which
typically requires the use of solvents to aid in the deposition of
the coating material and the flow of the coating material during
the coating step. Moreover, the coating material goes on wet and
must dry prior to handling of the substrate or prior to application
of any additional coatings that may be desired.
[0006] Solvent-based carriers and coating materials incur the added
expense of the solvent required to carry the coating material. The
drying stages typically require extra time, thus lowering
through-put for assembly line finish work. Dry coating and heating
of items to cure the paint coating also add to the finish time
required, which further reduces throughput.
[0007] Accordingly, what is needed is a system and method for
applying a coating to a substrate surface that eliminates the use
of solvents, electrostatic adhesion, final heating stages, and the
like. Further, what is needed is a method and system that provides
a uniform and high level of finish on a substrate that allows the
coating to dry in the shortest time possible, thus increasing
throughput.
SUMMARY OF THE INVENTION
[0008] According to the present invention, a coating apparatus and
method are disclosed that applies a coating to a product in a
uniform and controlled manner. The coating apparatus comprises a
feeding stage, an optional pre-treatment stage, at least one
coating stage and a finishing stage. The coating stage(s) comprise
a coating material feeder and a coating device. The coating device
includes an aperture conforming to the perimeter of a substrate to
be coated in a first and second dimension. As the substrate passes
through the aperture, coating material is applied in a uniform and
consistent layer ranging from 0.001'' to 0.250'' give or take
0.001''. The coating material also back fills minor surface
imperfections and blemishes on the substrate to achieve a
consistent finish across the whole area where coating material is
applied. The coating device includes first and second shell
portions. The first shell portion has a concave surface surrounding
the aperture portion. The concave surface allows for coating
material to collect prior to deposition upon the surface of the
substrate. The second shell has a substantially flat face and a
minor aperture that aligns with the aperture of the first shell.
Along the perimeter of the aperture in the second shell is formed a
groove, in which coating material collects in preparation of
coating the object as it passes through the apertures of both
shells.
[0009] Alternatively, the groove can include a bladder or balloon
like applicator that is supple and pliant enough to conform to the
surface of the object when the surface lacks a uniform perimeter
across its entire length. This allows for a three dimensional
application of the coating material over an uneven surface.
Additional coating stages are included in alternative embodiments
as well as finishing, drying, cooling, and other processing stages
desired.
[0010] The application of the coating material is useful in
finishing the exterior surfaces of base and crown moldings and trim
finish in home and office construction. The coating apparatus can
also be utilized in coating and finishing the surfaces of picture
frames, "wood" shutters and blinds, metal railings and trim.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In order that the manner in which the above-recited and
other advantages and objects of the invention are obtained, a more
particular description of the invention briefly described above
will be rendered by reference to a specific embodiment thereof
which is illustrated in the appended drawings. Understanding that
these drawings depict only a typical embodiment of the invention
and are not therefore to be considered limiting of its scope, the
invention will be described and explained with additional
specificity and detail through the use of the accompanying drawings
in which:
[0012] FIG. 1 is a block diagram illustrating various stages found
within a coating apparatus in accordance with the present
invention;
[0013] FIG. 2 illustrates a product passing through a coating
device of FIG. 1 showing a non-coated stage and a coated stage;
[0014] FIG. 3 illustrates the coating device shown in part in FIG.
2 in accordance with the present invention;
[0015] FIG. 4 illustrates an interior view of the coating faces of
the coating devices of FIG. 3;
[0016] FIG. 5 illustrates a profile formed in the aperture of the
coating device in accordance with the present invention;
[0017] FIG. 6 shows a partial cut-away view of the profile and
aperture having a channel about its perimeter for collecting the
coating material for application;
[0018] FIG. 7 illustrates a cross-sectional plan view of a
substrate having a coating applied and a profile matching that of
the aperture of FIG. 6;
[0019] FIG. 8A-D illustrate a complex profile possible with a
defined aperture in the coating device of FIG. 3 in accordance with
the present invention as well as the application of one type of
coating material to a portion of the substrate or to no portion of
the substrate;
[0020] FIG. 9 illustrates the use of a pliant bladder or balloon to
coat non-uniform surfaces of a product in accordance with the
present invention;
[0021] FIG. 10 is a schematic diagram of an alternative coating
apparatus in accordance with the present invention; and
[0022] FIG. 11 is a schematic diagram of an alternative coating
material delivery system contemplated within the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] FIG. 1 illustrates a schematic diagram of a coating and
finishing apparatus 10 in accordance with the present invention.
Coating and finishing apparatus 10 includes several stages that
perform preparation and cleaning of a substrate surface, as well as
the application of a coating to the substrate surface. Apparatus 10
can include additional stages to perform a second coating or more
of the same material on the substrate, or different coatings of
different coating materials on the same substrate until a finished
or desired result is achieved. Apparatus 10 also includes
additional stages to handle the substrate after coating such as
final inspection, packing, or a temporary transition for the
purpose of performing additional finishing stages to the
product.
[0024] Apparatus 10 includes a feeding stage or feeder 12 that
handles blank samples prior to pretreatment and coating application
performed in the later stages of apparatus 10. Apparatus 10
typically operates in conveyor form to process a plurality of
substrate samples in a given hour. The rate of which the number of
elements can pass through apparatus 10 is dependent upon the
complexity of the treatment of the blanks prior to coating, the
number of coats to be applied to the substrate after pretreatment,
whether any cooling is necessary between coating stages, and what
type of finishing operations are performed at the end. Feeder 12
can handle long lengths of stock in blank form and cut them to
desired profiles prior to the pretreatment or additional coating
stages later performed along apparatus 10. Further, manageable
lengths stock may be fed via feeder 12 and then cut to finish size
after the pretreatment and application of the coatings has been
completed during the various stages along apparatus 10. Further
still, the actual cutting of the stock to the desired lengths may
be performed at any stage during the treatment of the stock whether
its between a first or second coating stage or any other coating
stage along apparatus 10. It is left to the skilled artisan to
determine at what stage the stock should be cut to size, if
necessary, prior to a particular coating operation step or
finishing stage.
[0025] Alternatively, although the feeder stage shown in this
example operates before the coating stage, it is possible to draw
the substrate through the coating stage. Thus, it is contemplated
that once the substrate is fed into the coating stage and passes at
least a portion there through, the exit end of the substrate may be
grasped to draw the substrate through the coating stage. The
feeding stage can be placed anywhere along the line of production
which provides the greatest efficiency.
[0026] Next, the stock is fed through pretreatment stage 14.
Pretreatment stage 14 actually can comprise several stages that are
typically performed prior to coating the stock material. For
example, pretreatment stage 14 can include apparatus that takes a
blank stock and forms it into a desired shape, such as, for
example, taking a wood, plastic or metal sample and milling it to a
desired profile prior to the coating stages. Additionally, it is
useful to clean the surface of the stock material prior to coating
so that the coating material will adhere completely and without
blemish upon the surface of the stock material. Furthermore, a
preheating device can be included to heat at least the surface of
the sample to match the temperature of the coating material and
enhance the finish of the coating material as it cools. Thus,
pretreatment stage 14 can also include cleaning stages that aid in
cleaning the surface of the stock material passing through
apparatus 10. The cleaning stages can include high pressure steam
cleaning, high pressure air cleaning, solvent cleaning application,
water bath cleaning, or other types of cleaning stages typically
appropriate for the type of stock passing through apparatus 10.
Since the type of stock passing through apparatus 10 can include,
but is not limited to, wood surfaces, wood hybrid products,
plastics, metals, fiberglass, and the like, an appropriate cleaning
stage would then be applicable.
[0027] Once the stock material is treated for application of a
coating, the stock material passes from pretreatment stage 14 to a
first coating stage 16. In many applications, a single coating
stage 16 is all that would be required for applying a single
coating of primer, paint, protectorant, or finish coat on the
surface of the substrate passing through apparatus 10. In other
applications, repeated coatings of the same material, or different
coatings of different finishes may be accomplished via the
remaining stages 2 through N shown as second stage 18 through N
stage 20.
[0028] One or each stage 16-20 may include a heating element to
heat the surface of the sample passing through just prior to the
application of the coating material so the coating material does
not cool too rapidly upon contact with the surface. This leads to a
higher quality in the finish result. Further, graduated cooling
stations may also be included after the coating is applied to
prevent the coating from cooling too rapidly for delicate coating
materials that require slower cool down times. In alternative
stations, where the coating material is insensitive to cooling
conditions, a rapid cooling station may be added for greater
through put.
[0029] First stage 16 applies a first coat on the substrate surface
passing through apparatus 10. In cases where there are slight
blemishes and imperfections on the surface of the substrate, the
thickness and uniformity of the coating being applied to the
surface serves to fill in these imperfections and blemishes
completely resulting in a uniform finish over the entire surface of
the substrate. FIG. 2 illustrates the surface of a substrate 26
material prior to (26A) and just after (26B) passing through first
stage 16. The portion prior to passing through first stage 16,
substrate 26a, shows a plurality of blemishes and pock marks on the
surface. Once the substrate passes through first stage 16, the pock
marks and blemishes are filled in by the coating material so as to
achieve a uniform finish across the entire surface of the coated
substrate as embodied in substrate 26b.
[0030] In the example shown in FIG. 2, substrate 26 actually passes
through two stages, first stage 16 and second stage 18. First stage
16 applies a first coat of material to the surface of the substrate
while second stage 18 applies a second coat before the substrate
exits and is supported by rollers 28. Rollers 28 also serve to
transport substrate 26 from is one stage to the next and are
included where needed between stages or after final finish. Each
roller 28 may be coated with a non-stick, non-mar material, such as
TEFLON, to prevent the substrate to stick to it while the coating
material is cooling or hardening.
[0031] Each stage 16 and 18 includes a coating material feeder 30,
which feeds fluid coating material for application to the substrate
surfaces. An excess material return may also be provided. Further
more, each stage 16 and 18 can include a heating element 32 to help
keep the coating material in a fluid state to allow it to coat the
substrate during operation.
[0032] In some applications, first stage 16 merely applies a primer
coat that adheres more readily to the surface of the desired
substrate than the subsequent coat(s), typically the color coat or
finishing coats applied to the substrate. The thickness of the
material applied to the surface of the substrate can be as thin as
0.001'' to a thickness of 0.250''.+-.0.001''. If only a primer coat
is applied to the substrate, then the substrate passes from the
first stage to the second stage 18.
[0033] Second stage 18 either duplicates the steps performed at
first stage 16 or applies a second and completely different type of
coating material than that applied in first stage 16. If a primer
coat is applied during first stage 16, then a secondary coat or
even a finish coat may be applied during second stage 18. The
coating material used in second stage 18 typically adheres better
to the primer applied in first stage 16 than it would directly to
the surface of the substrate. When the substrate passes from first
stage 16 to second stage 18, the coating material typically is
applied in a thin enough and controlled manner so that the coating
material dries nearly instantaneously upon exiting one of the
stages. This allows the second coating stage to be performed
without requiring a cooling or drying step. On those occasions
where the coating material is applied rather thickly and a cooling
stage is necessary, such can be implemented between stages so that
the substrate is dry enough to accept the coating applied in the
next stage down stream from the previous stage. Further, the
coatings are being applied without the use of solvents or carriers,
which typically require additional drying time, thus saving time of
application and increasing throughput of stock or substrate
materials.
[0034] Once the substrate has passed through the second stage 18,
and there are additional coatings yet to be applied to the
substrate, the substrate will then pass through the appropriate
additional stages up to the Nth stage 20 until a desired result is
achieved. Further, should the last stage 20 apply a coating that
requires cooling, the substrate material passes through cooling
stage 22. The cooling stage is utilized at times because the
coating material typically is heated well above ambient temperature
so that the coating material will flow in fluid or liquid form. The
cooling stage cools and dries the coating material to a desired
hardness. Such cooling stages can typically include fans
circulating forced air to cool the coating material or the cooling
material may be quenched in a water or other liquid bath
appropriate for the coating material as desired.
[0035] Lastly, the substrate passes to the finishing stage 24.
Finishing stage 24 can include various operations to be performed
on the finished substrate at this time. These operations can
include merely stacking the substrate, cutting the substrate into
desired lengths and then stacking the substrate, or simply feeding
the substrate to a human operator for manual stacking as desired.
The finishing stage can also include a final inspection to confirm
that the finish is acceptable. Additional finishing stages will be
readily apparent to those skilled in the art.
[0036] A coating apparatus 50, such as that of FIG. 1 that uses
first stage 16, second stage 18, or any of N stage 20, is
illustrated in greater detail in FIG. 3. Coating apparatus 50
includes a coating material chamber 52, a coating extruder 54, and
a coating die 56. Coating chamber 52 attaches to coating die 56 so
that the coating material may travel from the chamber to die 56 for
application to the substrate as the substrate passes through die
56. A heater 58 connects to chamber 52 and to extruder 54 to heat
the coating material to a fluid state. The coating apparatus 50
further includes a feeder assembly tray 60 and an exit roller stand
62, which comprises 28 of FIG. 2. The feeder assembly tray 60 feeds
stock to be processed and coated during operation. Exit roller
stand 62 receives stock 26 after passing through stage 56. Feeder
assembly tray 60 further includes a stock delivery system 64, which
can be a belt loop pressed against the substrate 26 to control the
delivery rate of the substrate through stage 56.
[0037] Die 56 further includes an aperture that has a two
dimensional profile matching that of the substrate. Since the die
typically is made from a metal or other hard and durable substance
for repeated and long term use, the dimensions of the aperture are
fixed. The dimensions of the substrate are then adjusted to account
for the coating finish to be applied during this stage. The initial
dimensions of the substrate are set as the substrate passes through
the pretreatment stage 14. The milling operation typically sets the
initial dimensions of the substrate prior to passing the substrate
to the various coating stages downstream in apparatus 10.
[0038] Coating material chamber 52 holds a given quantity of
coating material. The coating material typically is a dry material
in pellet form such as, but not limited to, acrylics, polyesters,
polypropylenes, polyethylene, polyvinylchlorides (PVC),
polyolefins, or as ASA. The coating material can comprise an alloy
of any of the previously listed materials involving two or more
elements. The material can be in powder or liquid form as well and
is not limited to pellet form. Pellet form is used because of its
ease of handling over liquid or powder forms. Additional materials
are included in the coating "recipe" such as color pigment, UV
stabilizers, emulsifiers, rubbers, and other types of stabilizers
necessary to ensure a durable and appealing finish to the coating
applied to the substrate. The bulk carrying material, which
primarily functions as a binder to the substrate, is selected from,
but not limited to, acrylics, polyesters, etc. and typically
comprise between 70 to 80 percent of the coating material. The
pigmentation typically includes about 10 percent of the coating
material. The remaining 10 to 20 percent of the coating material
incorporates the UV stabilizers, emulsifiers, and other elements
previously mentioned.
[0039] The material placed within chamber 52 is heated by heater 58
to a liquified or fluid temperature state that allows the mixture
to flow either via a pump or gravity fed via extruder 54. As the
coating material now is in a liquid or fluid state, it travels to
the cavity formed within coating device 56 until it surrounds the
perimeter of the aperture in the coating die. Once a sufficient
amount of coating material collects within the cavity and along the
perimeter of the aperture, the coating material is ready to be
applied to the substrate as the substrate passes through die
56.
[0040] The substrate then passes through die 56 in conformance to
the profile matching the die. As the substrate passes through the
die profile, the coating material is applied directly to the
surface of the substrate in a controlled manner or within the
tolerances allowed by the die relative to the substrate surface.
The physical action of the coating material application can be
either hydrostatic coating or constriction as the substrate passes
through the die where the coating material perimeter is smaller
than that of the substrate perimeter, thus forcing the substrate
perimeter to contact the smaller perimeter formed by the coating
material within die 56. The coating material is applied in very
fine coats, ranging from 0.001'' to 0.250''.+-.0.001'', thereby
accurately controlling the amount and thickness of coating material
applied at this time. The ability to control the actual thickness
of the coating material eliminates the excess over spray that
typically is found in solvent-based spray systems known in the art,
as well as the excess application of coating material in a ribbon
coating system.
[0041] In an alternative embodiment, as shown in FIG. 9, the
perimeter of die 56 can include a pliant liner that is able to
conform to the substrate surface should the surface of the
substrate have a non-uniform profile. This allows apparatus 10 to
apply coating material uniformly across a surface in a three
dimensional manner. Where the perimeter of die 56 is fixed, the
cross sectional perimeter of the substrate must be fixed at all
times as it passes through the die. For example, the liner can
include a pliable rubber or polyvinyl material that can give to
conform to the changing profile of the substrates as it passes
through the die. Also, the liner can include a pliant bladder or
balloon-like device that has a rather large surface area in
comparison to the hard edge of a fixed perimeter application die
56. The bladder or balloon is filled with either air or liquid and
causes the exterior surface of the bladder to cover the substrate
and coat the surface completely, whether the surface has a uniform
or varying profile. The bladder can comprise more than one piece
and surround the perimeter of the aperture through which the
substrate passes. Further still, the bladder can have a donut or
toroid-shape that allows passage of the substrate through the
center opening of the toroid.
[0042] FIG. 4 illustrates a perspective view of coating die 56 when
split open to show the interior construction. Coating die 56
typically comprises two portions a first die shell 70 and a second
die shell 72. The first die shell 70 includes a cavity 74 formed
within a first face 76 around the perimeter of the aperture 71
through which the substrate passes. Cavity 74 provides a collecting
cavity for the coating material as it transports from coating
chamber 52 to die 56. Second die shell 72 typically includes a
substantially planar face 78, which meets with the cavity 74 and
face 76 of die shell 72 in such a relation that the aperture of die
58 matches with a similar, but mirror-shaped aperture 73 found in
second die face 78. Along the inner perimeter of the aperture
formed in die shell 72, is a receiving channel 80 in which the
coating material further collects to allow the substrate to pass
through the coating material and apply the coating material to the
surface of the substrate during the coating step. Channel 80 may
either have an interior radius R, a slant at a given angle, such as
45 degrees or any other desirable angle, or have a substantially
square or rectangular shape. The requirement is that the channel
formed around the perimeter be sufficient enough for the coating
material to collect in sufficient quantity so as to apply a uniform
amount of coating material around all the dimensions of the
substrate.
[0043] FIG. 5 illustrates a perspective view of die 56 where the
substrate exits after coating. FIG. 6 illustrates a perspective
cut-away view of the opposite, interior side of die 56 where the
substrate moves in the direction of the arrows. Notice how the
profile of the aperture of die 56 matches that of the substrate 84
shown in cross-sectional form in FIG. 7.
[0044] In another alternative embodiment, selected portions of the
die aperture may be blocked off. FIG. 8 illustrates various
configuration of how the damn may be implemented. In FIG. 8A, the
entire outer surface of substrate 86 is coated with a uniform
finish. Further, should only 3 sides of a 4-sided perimeter of the
substrate be coated, as shown in FIG. 8B, the fourth side can be
blocked so that no coating material is applied to that surface.
Further, should the user only want paint applied to a single
surface, then the remaining sides can be blocked. This is also
helpful when more than one color scheme is desired. Accordingly,
several stages can be utilized, each stage being blocked so that
only a single application in a give location is made, which
application does not overlap with the other color application to
apply either 2-tone or other multiple-tone color schemes. FIG. 8C
illustrates a multi-colored scheme of coating material applied to
substrate 86. FIG. 8D shows multiple color coatings on different
portions of the substrate as well as bare portions that were
blocked during each coating stage.
[0045] Further still, a section of the same surface can be blocked
so that coating material is applied only to that open surface
section. This is also helpful when a multiple color scheme is
desired. Moreover, the blocking of certain sections is useful when
it is apparent that the portion not being coated is intended to be
hidden from view so aesthetically it is not required to actually
coat the entire surface. For example, when the substrate is to be
used as a base board or crown molding, the back side and
non-exposed edges need not be coated. This saves materials and
time, thereby reducing costs to the producer and the consumer.
[0046] An alternative coating apparatus embodiment is shown in FIG.
10. Apparatus 90 includes substrate handling stage 92, similar to
that of feeder 12 or pretreatment stage 14 of FIG. 1. A coating
stage 94 is also included. Coating stage 94 heats the coating
material to a fluid and workable state so that the material can be
sprayed onto the surface of the substrate by a nozzle 95 as the
substrate feeds through apparatus 90. A heating element 96 is also
placed in the nozzle as an option. The heating of the nozzle keeps
the coating material in a fluid state with less build of residual
coating material. Further, heating element 96 can vary its
temperature to match the optimal temperature for spraying the
coating material onto the substrate before cooling too quickly and
resulting in less than optimal finishes. The temperature is
dependent on other factors such as ambient temperature, coating
material being used, distance set from the substrate to be coated,
and thickness of coating to be applied. The spray nozzle can be air
driven or airless. The use of heating element allows for the
coating material to be delivered sans carrying agent such as
lacquer, thinner, or other solvent type coating materials of the
prior art. This allows for faster hardening of the coating material
and lower costs of material in eliminating difficult solvents or
carriers. Additional, a faster hardening time allows for greater
throughput.
[0047] Yet another embodiment of the coating apparatus according to
the instant invention and shown in FIG. 11 utilizes a gravity fed
coating chamber or vat that allows for stock items to be coated to
be dropped and drawn through the coating material, then finished by
passing through the coating die 56 in a substantially vertical
direction. The coating material can be maintained viscous enough
that the aperture prevents the material from flowing out of the die
56, yet still achieving a quality finish on the product. The finish
results approach those of the
[0048] The types of product that are finished within coating
apparatus 10 include, but are not limited to: Base and crown
molding in home and business construction; trim work for interior
and exterior applications in home and business; picture frame
surface finishing; "wood" blinds and shutters; metal trim and
finish work; coating plastic or rubber substrates; coating large
planks, such as 4'.times.8' panels; and vinyl or metal siding.
[0049] The substrate or product intended to be coated can be any
study object including metal, metal-type objects, wood, wood-based
products, medium-density fiberboard (MFB) synthetic substrates such
as plastics, glass, glass-based products, and anything else that is
substantially rigid so that its shape is maintained as it passes
through the die.
[0050] The invention may be embodied in other specific forms
without departing from its spirit or essential characteristics. For
example, although only a single coating apparatus is depicted in
the drawings, it would be readily apparent to one skilled in the
art that is multiple stages could be placed in parallel.
[0051] The parallel operation of a plurality of coating lines would
increase throughput over a single line system. Thus it is
contemplated that parallel operating, multiple coating line systems
would be implemented based on the coating apparatus disclosed in
the instant invention.
[0052] The described embodiments are to be considered in all
respects only as illustrative and not restrictive. The scope of the
invention is, therefore, indicated by the appended claims rather
than by the foregoing description. All changes which come within
the meaning and range of equivalency of the claims are to be
embraced within their scope.
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