U.S. patent application number 09/736696 was filed with the patent office on 2001-04-26 for valve disposition and configuration designed to improve color dosing response time in a process of coloring polyurethane products.
Invention is credited to Chavis, Jimmy D., Kochanowicz, Christopher T., Pitman, F. Mark, Ragsdale, Mark E..
Application Number | 20010000452 09/736696 |
Document ID | / |
Family ID | 23310693 |
Filed Date | 2001-04-26 |
United States Patent
Application |
20010000452 |
Kind Code |
A1 |
Kochanowicz, Christopher T. ;
et al. |
April 26, 2001 |
Valve disposition and configuration designed to improve color
dosing response time in a process of coloring polyurethane
products
Abstract
This invention relates to an improved procedure and apparatus
for making colored polyurethane foam products, such as carpet
underlay and the like, as well as the improved colored product
itself. Such a procedure entails the utilization of at least one
valve assembly within a color dosing manifold such that the valve
itself is simultaneously in contact with both the outside surface
and the inside surface of the manifold. Such a disposition for a
valve assembly permits color to be introduced directly into a
binder (i.e., polyol and isocyanate) or polyol stream in order to
substantially eliminate any color remaining in contact solely with
the inside walls of the manifold. This in turn permits thorough
mixing of the binder and colorant and substantially reduces the
response time from opening the valve to producing colored
polyurethane materials (such as polyurethane foam), thereby
effectively eliminating the production of waste polyurethane
product. The inventive configuration comprising a specific type of
ball valve and/or the placement of a plurality of such disposed
valves in a radial configuration on the manifold are also
contemplated within the invention.
Inventors: |
Kochanowicz, Christopher T.;
(Spartanburg, SC) ; Chavis, Jimmy D.;
(Spartanburg, SC) ; Pitman, F. Mark; (Duncan,
SC) ; Ragsdale, Mark E.; (Duncan, SC) |
Correspondence
Address: |
Milliken & Company
P. O. Box 1927
Spartanburg
SC
29304
US
|
Family ID: |
23310693 |
Appl. No.: |
09/736696 |
Filed: |
December 13, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09736696 |
Dec 13, 2000 |
|
|
|
09335197 |
Jun 17, 1999 |
|
|
|
Current U.S.
Class: |
366/173.1 ;
366/182.4 |
Current CPC
Class: |
B01F 2101/30 20220101;
B29K 2105/04 20130101; B01F 2101/2805 20220101; B29B 7/60 20130101;
D06P 3/241 20130101; B29K 2105/0032 20130101; B01F 35/834 20220101;
B01F 35/712 20220101; B01F 35/71805 20220101; B01F 25/311 20220101;
B29K 2075/00 20130101; D06P 5/08 20130101; F16K 11/0876
20130101 |
Class at
Publication: |
366/173.1 ;
366/182.4 |
International
Class: |
B01F 005/04; B01F
015/02 |
Claims
What we claim is:
1. A method of producing a colored polyurethane article comprising
the steps of (a) providing a binder composition comprising at least
one polyol and at least isocyanate within a manifold, having an
inside and outer surface, attached to a valve assembly, wherein
said valve assembly is oriented such that it is simultaneously in
contact with both said inside and outer surfaces of said manifold;
(b) introducing a liquid colorant into said valve assembly
including a ball valve; (c) introducing the colorant from within
the valve assembly of step "b" into said binder composition of step
"a"; and (d) allowing said binder composition constituents to react
to form the desired colored polyurethane article.
2. The method of claim 1 wherein said ball valve of step "b" has
first and second channels; wherein each channel is exclusive of the
other; wherein said first channel has a first opening and a second
opening, both of which are located at different locations on the
spherical ball valve surface; and wherein said second channel has a
first opening and a second opening, both of which are located at
different locations on the spherical ball valve surface.
3. The method of claim 2 wherein said ball valve of step "b" is a
spherical ball valve having an x-axis, a y-axis, and a z-axis;
wherein said first channel is located on said x-axis; and wherein
said second channel is located on either said y-axis or said
z-axis.
4. The method of claim 3 wherein said spherical ball valve
comprises a first opening of said first channel at a location of
approximately 0.degree. on said x-axis and a second opening of said
first channel at a location of approximately 180.degree. on said
x-axis; and wherein said first opening of said second channel is at
a location on said y-axis and said second opening of said second
channel is at a location on said z-axis.
5. The method of claim 4 wherein said first and second channels of
said spherical ball valve are straight and have the substantially
the same bore size.
6. A colored polyurethane article produced by the method of claim
1.
7. A colored polyurethane article produced by the method of claim
2.
8. A colored polyurethane article produced by the method of claim
3.
9. A colored polyurethane article produced by the method of claim
4.
11. A colored polyurethane carpet underlay produced by the method
of claim 5.
12. A colored polyurethane carpet underlay produced by the method
of claim 1.
13. A colored polyurethane carpet underlay produced by the method
of claim 2.
14. A colored polyurethane carpet underlay produced by the method
of claim 3.
15. A colored polyurethane carpet underlay produced by the method
of claim 4.
16. A colored polyurethane carpet underlay produced by the method
of claim 5.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
1. This application is a divisional of co-pending application
09/335,197, filed on Jun. 17, 1999.
FIELD OF THE INVENTION
2. This invention relates to an improved procedure and apparatus
for making colored polyurethane foam products, such as carpet
underlay and the like, as well as the improved colored product
itself. Such a procedure entails the utilization of at least one
valve assembly within a color dosing manifold such that the valve
itself is simultaneously in contact with both the outside surface
and the inside surface of the manifold. Such a disposition for a
valve assembly permits color to be introduced directly into a
binder (i.e., polyol and isocyanate) or polyol stream in order to
substantially eliminate any color remaining in contact solely with
the inside walls of the manifold. This in turn permits thorough
mixing of the binder and colorant and substantially reduces the
response time from opening the valve to producing colored
polyurethane materials (such as polyurethane foam), thereby
effectively eliminating the production of waste polyurethane
product. The inventive configuration comprising a specific type of
ball valve and/or the placement of a plurality of such disposed
valves in a radial configuration on the manifold are also
contemplated within the invention.
BACKGROUND OF THE INVENTION
3. Polyurethane foam carpet underlay products are utilized to
provide cushioning benefits for pedestrians since carpet is usually
placed over hard floors, such as concrete or wood. Such carpet
underlay thus should provide a uniform and even cushioning effect
over the entire covered area. Furthermore, there are certain
aesthetic qualities which are demanded in the marketplace for such
carpet underlay products as concerns colorations and appearances.
These demands have been met in the past through the utilization and
introduction of colorants through one or more pipes or injectors,
arranged consecutively and serially (if a plurality is present),
through connections (feed lines, etc.) feeding to a manifold, and
ultimately into binder compositions comprising the standard
polyurethane reactants (polyols, such as ether triols, and the
like, and isocyanates, such as methyl diphenyl diisocyanate, and
the like, as merely examples; any standard polyol and isocyanate
utilized to produce polyurethane in this industry may be used). The
pipes or valve assemblies have been disposed in the past by merely
creating a hole in the manifold to which the pipe or valve assembly
is attached. The colorant would then be fed (by pressure or
gravity, for instance) through the pipe or valve assembly and
emptied into the binder stream travelling through the manifold.
These colored compositions are generally mixed by a binder pump and
sprayed onto scrap foam to form the desired carpet underlay
product. Such a standard method has proven inefficient and
problematic in the past since the through-pressure of the
travelling binder stream is not always constant and thus the mere
introduction at the walls of the manifold has not provided
sufficient ability to thoroughly mix the colorant within the binder
stream (in fact, the colorant remains in contact with the manifold
wall rather than being "injected" into middle of the binder
stream). This procedure thus leads to uneven coloring,
discolorations, coagulation of binder and colorant, and the
production of undesirable and potentially costly waste foam.
4. As a result, the demand for the introduction of a wide variety
of colors in binder compositions for the production of polyurethane
foam carpet underlay products has resulted in a significant move to
blend-on-fly color dosing units based on the use of polymeric
colorants. In this case color metering equipment is used to
accurately dose two or more colors that are injected into the
polyol stream and subsequently mixed in a binder pump to provide
the correct shade and depth of color. The biggest advantage of this
type of approach is that now an unlimited number of colors can be
made from 1 to 5 "primary" colors blended on-the-fly. For example,
a typical colored polyurethane product, carpet underlay, is colored
and produced through a system based upon a binder/colorant shot
process (i.e., color is introduced simultaneously with the start of
a binder pump and stops when the pump is shut off, thus eliminating
the introduction of additional color into the manifold). Changes
from light and/or dark shades and color changes from one hue to
another can be accomplished with a minimal amount of binder flush
through the manifold thus reducing the amount of off-quality foam
produced during the color change procedure. Thus, changes from one
dark color to the next can usually be accomplished in relatively
short distances minimizing the amount of foam that must be scrapped
as a result of the color change. Light shades have proven to be
more of a challenge since the color throughput is substantially
lower causing the response time to increase before changes actually
made in the system can take effect. As a result, a means was needed
to reduce this response time to an acceptable level thus minimizing
the length of time required to change from one color to the next
even at low flow rates (approaching 2 grams per minute or
less.)
5. A means was also needed to produce even colorations in the final
product, as well as to possibly reduce the amount of coagulated
binder/colorant (that is coagulated or crystallized portions of the
colorant combined with the polyol and the isocyanate of the binder
composition). Such a coagulant theoretically produces patches or
areas of "hardness" within the carpet underlay product. As such a
product desirably provides a uniformly cushioned, soft feel as a
layer between the carpet and the hard floor underneath, any
coagulated binder/colorant will produce unwanted, deleterious areas
of "hardness."
6. Thus, it was necessary to develop a configuration and/or
utilize, within this specific configuration, a specific valve
assembly in order to facilitate effective on-the-fly polymeric
colorant blending with even colorations in the final product and
substantially reduced, if not eliminated, binder/colorant coagulant
production. To do this it was first necessary to realize that the
current standard configuration utilized either a single colorant
"injector" (i.e., pipe, valve, etc.) on the dosing manifold, or a
plurality of "injectors" aligned consecutively and serially on the
manifold (i.e., one after the other), such that the "injectors"
would merely be used to transfer colorant to a location in very
close proximity to the manifold inner wall. Such a limited manner
of "injecting" colorant resulted in the problems discussed above
since the colorant would not become thoroughly mixed and, in
conjunction with the laminar flow of the binder through the
manifold, would basically remain in contact with the manifold
rather than become thoroughly mixed within the binder stream. Thus,
it was reasoned that the main problem with the traditional method
of producing polyurethane foam could be alleviated through the
utilization of a newly modified valve assembly which extends within
the actual manifold rather than remains at a location outside the
manifold. Accordingly, this invention provides apparatus for the
production of polyurethane foam carpet underlay comprising a
mechanism for the introduction of colorant within a binder
composition; wherein said apparatus comprises a manifold comprising
an inside surface and an outside surface, within which said binder
composition and said colorants are mixed together, which leads to a
binder pump; wherein said apparatus comprises at least one valve
assembly through which said colorants are transferred from a feed
line to said manifold; and wherein said at least one valve assembly
is disposed within said manifold such that said at least one valve
assembly is simultaneously in contact with both said outside
surface and said inside surface of said manifold.
7. Furthermore, in other polyurethane producing procedures,
colorants have traditionally been added strictly to the polyol
component prior to its ultimate reaction with isocyanate to form
the target polyurethane article (such as foam, carpet underlay, car
bumpers, and the like). However, such formulators do not always
produce colored polyol compositions since uncolored foam products
are also desired by consumers. Thus, the polyol producer generally
mixes and formulates the desired polyol/colorant compositions and
ships such to its customer polyurethane producer. Polyol production
generally is performed in a single dedicated mixing vessel for cost
purposes. If a batch of polyol is to be colored, the formulator
must thoroughly mix the polyol and colorant constituents in such a
vessel. However, should a further polyol composition need to be
produced without added colorant, the mixing vessel must be
thoroughly cleaned after each production of polyol/colorant
composition (especially when pigments are utilized). This
cost-cutting thus has translated into limited choices of color
since the formulator generally produces either uncolored or a
single color of polyol (such as black, from a black pigment).
Additionally, the color response time from the dispensing of
colorant to the clear introduction of colorant within the target
polyol composition is generally is very high with the systems now
in use (i.e., valve assemblies attached to the outside of a
manifold which introduce colorant into the manifold at the surface
of the inner wall). For instance, and merely as one example, the
following measurements were undertaken with the standard valve
assemblies now utilized: Through a one inch manifold a polyol
composition was pumped at about 466.5 grams per minute. Color was
added at a rate of 11.1 grams per minute at an injection point
eighteeen inches from a standard gear pump followed by an
additional eighteen inches of pipe from the discharge port on the
pump to an outlet. Upon actuation of the valve assembly to a
dispense mode, a total time of 35 seconds was required before
colorant was located within the polyol composition past the outlet.
However, when the inventive valve configuration was practiced, a
total time of seventeen seconds passed prior to colorant
realization in the polyol composition. Furthermore, upon switching
the traditional valve assembly (which permits colorant to travel
down the manifold inner walls) to recirculation mode (thereby
preventing the introduction of more colorant within the manifold),
a total time of 120 seconds was measured before colorant
disappeared from the polyol final product. Upon use of the
inventive valve assembly, a total time of between 25 and 30 seconds
was necessary for a full depletion of colorant within the target
polyol. Thus, clearly, the introduction of colorant into the center
of the binder stream afforded both quicker starting times and
ending times (and thus a substantial reduction in the production of
waste polyurethane).
8. The inventive valve assembly configuration provides a vast
improvement to polyol formulators and ultimate foam producers in
permitting greater flexibility in color choices with the
facilitation of potentially costly clean-up efforts since the new
valve-added manifold permits the manufacture of all uncolored
polyol compositions within the formulator's mixing vessel. The
colorant can then be added directly to the polyol in its final
shipping container through the utilization of the inventive
valve/manifold assembly by permitting thorough mixing of the
colorant and polyol through the introduction of the colorant
directly into the stream of polyol (binder) during the transfer of
the polyol from the mixing vessel into the shipping container (tote
bin, tank truck, and the like). Since the valve assembly "injects"
the colorant into the center of the transferred binder stream, the
colorant will not appreciably coat the walls of the manifold or
remain stagnant within the manifold (and thus no coagulation will
occur).
9. The particular valves may be of any structure themselves;
however, preferred valves are specific ball valves which comprise
two exclusive channels to permit instantaneous switching from
dispense to recirculation mode which are discussed in greater
detail below. Also, a preferred, but not required radial
configuration of a plurality of valve assemblies on the manifold
has proven to be most effective in providing thorough and highly
desirable colorations through the mixing of different colorants
within the binder stream itself. This effectiveness is most likely
due to the nearly immediate response time to an actuator signal
each valve allows since they are equidistant from the same mixing
binder pump. Such a configuration is particularly suited for
introducing (such as by injection) colorants into target binder
compositions (comprising polyols) for the ultimate production of
target polyurethane foam products (most importantly carpet
underlay) thereby allowing for a substantial reduction in potential
foam waste due to low colorations or discolorations. Furthermore,
as noted above, such a radial configuration substantially reduces
the binding together of excess colorant and binder which may
produce unsightly and uncomfortable areas of "hardness" in the foam
underlay. The resultant product was thus thoroughly and evenly
colored and exhibited an even cushioning over the entire
article.
10. In addition, and as noted above, it has been found that the
inventive valve assemblies may also comprise specific types of ball
valves which comprise two mutually exclusive channels running
through perpendicular planes of the ball, one remaining in the same
plane from entry through one side of the ball until exiting the
opposite side, the other entering the ball at one axis, and exiting
at a point 90.degree. from the point of entry on a different axis.
More particularly, the preferred ball valves utilized possess such
mutually exclusive channels exhibiting the same bore sizes as well
as the same bore sizes as the dispense port into the manifold. This
ball valve facilitates quick and efficient movement of the valve
from recirculation to dispense mode with minimal, if at all,
leakage or loss of colorant. Such use of the ball valve also
results in a rapid build up of pressure and hence almost
instantaneous feed (and minimal, if any, pressure drop upon
movement of the valve between modes). In addition to rapid
initiation of color flow, it has been found that the exigencies of
the situation also require the ability to almost instantaneously
interrupt the flow of colorant even at high throughput pressure
when the color was switched from dispensing mode back to the
recirculation mode. This requirement theoretically prevents the
"bleeding" of color back into the manifold when the need for color
ends. The standard valve assemblies used today do not effectively
address this problem. As such, the near immediate start and stop of
color flow has been accomplished as a result of the utilization of
the particular ball valves within the current inventive method,
valve assembly configuration, and dosing apparatus.
11. Polymeric colorants (i.e., polyoxyalkylenated colorants) such
as those described in U.S. Pat. No. 4,284,279 to Cross et al.,
herein entirely incorporated by reference, have been used for a
number of years to color polyurethane foams, including carpet
underlays. Prior to the utilization of such polymeric colorants,
pigment dispersions were the main source of polyurethane coloring
compounds. Such dispersions have traditionally proven very
difficult to handle, too viscous for use within standard injectors,
highly staining and thus difficult to clean from standard injector
equipment (without the need for environmentally unfriendly
solvents), and very abrasive and thus potentially damaging to the
delicate machinery associated with coloring polyurethane foam. As a
result, polymeric colorants are widely accepted as the best
materials for coloring polyurethane foam carpet underlay
products.
12. In the past, custom blends of polymeric colorants were made
ahead of time using two or more "primary" colors prior to
incorporation within the target foam. The components would be mixed
together using some type of agitator such as a mixer or a drum
tumbler. Once the blend was of an appropriate shade it was
transferred to a storage tank for further introduction within the
foam substrate. Upon completion of coloring with a specific batch
of polymeric colorant, the previously run color would have to be
emptied from the storage tank; the tank would need to be cleaned;
and then the next color to be run in the same tank would have to be
charged in the tank. Cleaning of the tanks, feed lines (a.k.a.
pipelines), etc., was facilitated due to the water-solubility of
the polymeric colorants (particularly as compared to pigments);
however, the procedures followed were still considered labor
intensive and not cost efficient. The general practice was then
modified to maintain a dedicated tank for each separate color
(shade) that was to run. This led to a number of inefficiencies and
limitations that were not desirable if a foam manufacturer was to
adequately meet demands in the market place.
13. Polymeric colorants, such as those cited above in Cross et al.,
were designed to be totally miscible with one another as well as
with most polyols, one of the two main ingredients used to produce
polyurethane materials (isocyanates being the other). Pigment
dispersions, on the other hand, are particulates dispersed in some
type of liquid carrier. They require a high degree of agitation
before they satisfactorily blend together to provide a uniform
color. As a result, the short amount of time that the polyol and
colorant are mixed in the typical foam-producing apparatus' binder
pump is not sufficient to permit an adequate mixing of components
to insure a single, homogeneous coloration throughout the target
foam.
14. A configuration of this typical colorant production line for
colored carpet underlay foam is depicted in FIG. 1. This standard
coloring system itself generally consists of 1 to 5 "primary" color
storage tanks (three of which are depicted as 12a, 12b, 12c in FIG.
1) each feeding a stream of colorant through feed lines 13a, 13b,
13c to at least one (per feed line 13a, 13b, 13c) positive
displacement spur gear pump 15a, 15b, 15c coupled to a variable
speed motor/drive 14a, 14b, 14c (such as available from Viking).
The motor/pump combinations 14a, 15a, 14b, 15b, 14c, 15c are
typically run continuously in either recirculation or dispense mode
(depending on the position of a 3-way valve 11a, 11b, 11c) to
minimize the time required to spool up the motor 14a, 14b, 14c to
the proper rpm and to ultimately achieve the pressure required to
initiate color flow into a pre-mix manifold 8 through serially
configured 3-way valves 11a, 11b, 11c [and/or injectors (not
illustrated)]. The throughput pressures of each line are typically
measured through the utilization of pressure gauges 16a, 16b, 16c
attached to each feed line 13a, 13b, 13c from the pumps 15a, 15b,
15c to each 3-way valve 11a, 11b, 11c. The typical 3-way valves
11a, 11b, 11c are air actuated and used to direct the flow of
colorants from the recirculation feed lines 17a, 17b, 17c to the
dispense lines (not illustrated) to the manifold 8 when color flow
to the manifold 8 is required. The colorants will mix with a stream
of binder composition 10 comprising the polyurethane reactants
(polyol and isocyanate, as well as other potential additives). From
the manifold 8, the binder composition and colorants are moved to
the binder pump 9 for further and more thorough mixing of the
resultant binder/colorant composition. The resultant composition is
then sprayed onto a substrate (such as scrap foam, not illustrated)
to produce the desired polyurethane foam carpet underlay product
(not illustrated). Although this configuration has proven effective
in the past, there remain a number of problems associated with this
procedure which have heretofore been unresolved.
15. For instance, the market place demands that a polyurethane
producer be able to provide shots of binder to produce dark shades
as well as light shades with a variety of hues and at differing
polyol flow rates. Since color is metered volumetrically, a wide
range of color flow rates are required to insure low enough flow
for a minor component in a light shade. In addition, the polyol
flow rates can be as low as 14 kg/min and as high as 55 kg/min
[color loading is generally stated in weight percent of binder (wt.
%)]. As the rate at which the polyol flow is reduced so must the
color rate be reduced to maintain the same wt. %. For most
polyurethane products manufactured in the United States, the color
delivery systems must be able to provide color flow as low a 2
grams/min and as high as 3000 grams/min or more. The rate at which
color begins to flow when pumping 3000 grams/minute is generally
very different than pumping 2 grams/min until the present invention
is incorporated, for example. Prior to this point in time, the
general approach was to use a smaller diameter line for the low
flow range. Unfortunately, there are distinct limitations on such a
small diameter (small bore) feed line, most notably the resultant
throughput pressure drop from pumping material several feet through
a small diameter line.
16. Furthermore, the typical valves utilized in polyurethane rebond
(i.e., with the use of a binder component subsequently mixed with
isocyanate) foam coloring systems have a three-way air actuated
ball valve assembly (18 in FIG. 2) that is positioned approximately
three to six feet from the binder composition manifold (8 in FIG.
1) (such as 11a, 11b, 11c in FIG. 1). Due to the configuration of
the available ball valves, the corresponding feed lines are
generally arranged serially and consecutively on the outside of the
manifold (8 in FIG. 1). As provided by the representation of a
standard three-way ball valve assembly 18 in FIG. 2, material
metered by the pump enters the top of the three-way ball valve 19
from the storage tank feed line 20 and exits either through the
recirculation side 25 or the dispense side 22 depending on how the
ball is oriented. FIG. 2 depicts the ball valve 19 when it is
oriented in the recirculation mode. Once it is desired to change
from recirculation to dispense and back to dispense the ball valve
19 must typically rotate 180.degree. from one side of the ball
valve 19 to the other (although there are some apparati which
utilize a 90.degree. ball valve rotation) through the movement of
an actuator (not illustrated) attached to an actuator pin 23 which,
in turn, fits into an indentation (not illustrated) within the ball
valve 19. Furthermore, the typical ball valve 19 comprises a single
channel 21 to accommodate the flow of colorant to either the
recirculation side 25 or the dispense side 22. This single channel
21 is configured at a right angle and thus may contribute to
laminar flow problems by requiring the colorant liquid to radically
change direction, thereby altering the pressure over the total
liquid mass (and thus producing non-uniformity of pressures over
the entire liquid colorant).
17. In addition to this typical 3-way valve, a device must be used
to inject color away from the wall of the manifold to insure
adequate subsequent mixing (i.e., to reduce the problems associated
with laminar flow through a feed line having a larger diameter than
the 3-way valve). Ideally, such a device should function as a check
valve to maintain pressure in the line between the valve and the
manifold and to stop color flow when switching from dispense to
recirculation. Such devices must maintain pressure after the
dispensing unit is returned to recirculation mode otherwise the
pressure drops below the "cracking" pressure of the check valve
spring which will result in even longer startups which, in turn,
may translate into cost overruns, potentially greater amount of
off-quality colored foam, or foam containing numerous undesirable
"hardness" areas. Additionally, the resultant pressure drop must be
acceptable across a broad delivery range for such injectors to
alleviate any other related pressure difference problems. Also,
such check valves are effective in preventing binder from entering
valve assembly from the manifold. As such, the check valves are
prone to plugging due to the hardening of the binder in the highly
restrictive space. There have been no developments providing such
desired improvements or remedies to improve upon and/or correct
these problems accorded the industry by the prior art.
DESCRIPTION OF THE INVENTION
18. It is thus an object of the invention to provide a
configuration of valve assemblies around the manifold of either a
color dosing apparatus for polyurethane foam products or a transfer
system apparatus for polyol storage and shipment which provides
efficient and even colorations in the final product with very
little, if any, discolorations or waste foam. Also, an object of
this invention is to provide valve assemblies which permit
instantaneous switching from a recirculating component to dosing to
the injector without requiring a high throughput pressure. A
further object of the invention is to provide a low throughput flow
rate method of coloring polyurethane foam carpet underlay with a
valve assembly configuration and/or specific types of ball valves
within such specifically configured valve assemblies which
substantially reduce and possibly eliminate the production of
undesirable areas of "hardness" attributed to production of
colorant/binder coagulants within the manifold. Another object of
the invention is to provide a significant improvement in coloring
polyurethane foam carpet underlay over the prior art through the
utilization of valve assemblies having two-channeled ball valves
which allow for instantaneous on/off performance at a very wide
range of throughput pressures. Yet another object of this invention
is to provide a configuration of valve assemblies which
substantially reduces the problems associated with turbulent flow
of liquid colorants in a polyurethane foam coloring apparatus by
permitting introduction of the colorant material away from the
walls of the manifold (and thus potentially problematic resistance
and pressure changes through the entire system).
19. The aforementioned configuration of valve assembly which is
situated "within" a manifold and thus simultaneously in contact
with both the outside surface and inside surface of the manifold
(and extending into the manifold at least 5 millimeters and at most
a distance equal to the radius of the manifold) to "inject"
colorant away from the manifold inner walls and into the binder
stream. In such a manner, better control over the amounts of
colorants, particularly when blends are desired to produce specific
colors or hues within the target foams underlay product, is
provided which, in turn, results in lower amounts of off-quality
waste foam being produced. Furthermore, this configuration permits
a more accurate mixture of binder and colorant in order to
substantially avoid the aforementioned problems associated with
coagulation of these two components. In addition to this
configuration, it has been found that coating the inside of the
manifold with polytetrafluoroethane, also known as Teflon.RTM.,
available from DuPont, at least partially in the areas into which
the valves introduce the colorants, allows for more even flow
throughout the manifold of the binder and binder/colorant mixture.
The more even flow through the manifold, the less chance of
stagnation of the two components (and thus lowered ability to form
unwanted coagulants). Furthermore, the polytetrafluoroethane
coating provides a non-stick surface within the manifold which
increases the velocity of the binder/colorant along the manifold
walls thereby providing a more even throughput pressure through the
entire dosing apparatus. Preferably, the coating covers the entire
inside surface of the manifold.
20. Additionally, it has been found that specifically configured
ball valves provide the optimum performance for the dosing
apparatus having the particular plural valve assembly configuration
noted above. The individual valves may contain and/or utilize any
well known type of valve, since the valve assembly configuration is
the primary method of providing the aforementioned benefits in the
final carpet underlay product. However, as noted previously, the
best performance has been achieved through the utilization of
spherical ball valves having, individually, first and second
channels; wherein each channel is exclusive of the other; wherein
said first channel has a first opening and a second opening, both
of which are located at different locations on the spherical ball
valve surface; and wherein said second channel has a first opening
and a second opening, both of which are located at different
locations on the spherical ball valve surface. More succinctly,
these spherical ball valves permit the use of special 3-way valves,
each comprising two exclusive channels that allow the valve to
dispense from the bottom rather than feed from the bottom. An
injector may also be used with this valve assembly, but is has not
been found to be required for the dosing apparatus to function as
intended within the inventive method. Thus, with or without an
injector, each desired valve assembly provides instantaneous flow
regardless of the flow rate. In addition, this specific 3-way valve
with the specific spherical ball valve noted above, substantially
reduces, if not eliminates, the amount of leakage resulting from
the movement of the ball valve from dispense to recirculation mode,
or vice-versa. Thus, the specific ball valve facilitates an
instantaneous on/off switching between a dispensing feed line to an
injector unit and a feed line to a recirculation assembly (to
reduce the amount of colorant potentially wasted and to best insure
the throughput pressure of the entire apparatus remains uniform at
all times).
21. In particular, this ball valve comprises two exclusive
channels, one of which is positioned to direct the flow of colorant
to the recirculation assembly and the other to direct such a flow
to the injector. This is accomplished by having the two separate
channels be aligned on totally separate axes (for instance, one on
the x-axis and the other on either the y- or z-axis). More
specifically, the channel not on the x-axis must enter the
spherical ball valve at a point referenced as 0.degree. on the
particular axis and exits the spherical ball valve at a point
90.degree. on the same axis. In this manner, the two channels are
completely exclusive of another, thereby facilitating movement of
the valve between recirculation and dispensing modes. Furthermore,
the configuration of the non-x-axis channel reduces the change of
pressure on the liquid colorant through the valve than with a
standard right angle bending channel (it provides a sort of shunt).
Again, such a ball valve has proven to be highly effective in
providing the necessary instantaneous on/off (color response) times
as well as maintaining the proper flow rate (at an extremely wide
range from about 0.3 g/min to about 14,000 g/min).
22. An actuator is utilized, generally, to rotate this ball valve
into these specific positions. Such an actuator includes a pin
extending into the valve assembly, the end of which pin is shaped
to fit an indentation in the ball valve. The actuator then turns
the ball valve the requisite number of degrees to align the
respective channel to the desired feed line (90.degree. is
preferred, although, in some instances, 180.degree. may be
possible). Preferably, the ball valve channel and the optional
injector would possess the same bore size.
23. Furthermore, it is important to note that production of
environmentally unfriendly waste (off-quality) colored polyurethane
foam carpet underlay has been caused by delayed colorant flow
(throughput flow rate), pressure drop, turbulence problems (which
themselves are attributed to disruption of laminar flow through the
manifold), uneven colorant introduction into the binder, and the
colorant dispensing feed line (to the injector), and the injector
within standard polyurethane foam carpet underlay coloring
apparati, and the like. The inventive configuration of a plurality
of valve assemblies, as well as the polytetrafluoroethane manifold
coating, and the specific spherical ball valve noted above, have
all proven successful in curing and reducing the deleterious
effects of these problems. For instance, with regard to the ball
valves, standard three-way valves utilize ball valves comprising
single channels for directing colorants. In general, these channels
are formed in such a way to require a right angle turn of the
colorant liquid through the valve assembly either to the injector
feed line or to the recirculator feed line (see FIG. 2 and
discussion thereof, above). Such a change of direction potentially
increases the turbulent flow problems associated with the movement
of liquid colorants through feed lines (since the flow of discrete
portions of the liquid material will not be substantially uniform)
and can subsequently result in deleterious pressure changes which,
again, can result in off-quality foam production. The inventive
ball valve assembly has provided a means to avoid all of these
problems and potentially damaging circumstances, particularly where
the bore size of the channels of the ball valve and the feed line
through the injector and to the manifold are also substantially the
same.
24. Also, a plurality of valves on the outside of the manifold
within the foam-producing apparatus permits the introduction
simultaneously of different polymeric colorants into the binder
stream. As noted previously, the ability to simultaneously "inject"
colorants from different valve permits better production of more
pleasing shades of color through mixing at the same location
equidistant from the binder pump mixing head.
25. Thus, the invention permits a substantial reduction (almost
total elimination) of waste carpet underlay foam upon the
utilization of (i) valve assemblies which more definitively and
thoroughly feed colorant into the binder stream itself; (ii)
simultaneously feeding valve assemblies for introduction of
polymeric colorants (through the configuration of plural valve
assemblies noted above), (iii) very low, but highly desirable, flow
rates through the dosing mechanism (which also allows for the
utilization of an extremely wide range of flow rates without an
appreciable pressure drop through the entire apparatus), (iv) a
polytetrafluoroethane coating on at least a portion of the inside
surface of the manifold to increase the velocity of the
binder/colorant along the walls of the manifold and to reduce the
stagnation of binder and colorant together for an undesirable and
appreciable amount of time within the manifold, and the like.
Additionally, a method of coloring such polyurethane foam carpet
underlay products utilizing a dosing mechanism comprising the
specific valve assembly configuration within a manifold is
encompassed within this invention. Furthermore, the arrangement of
valve assemblies disposed radially around the circumference of a
manifold as discussed above, and the resultant colored polyurethane
foam carpet underlay product are encompassed within the instant
invention.
26. The term "polyurethane foam carpet underlay product" is a well
known description of cured polyurethane foam, made from the
reaction of polyols and isocyanates, which is uncolored and fed
through a coloring apparatus in its bulky foamed state and which is
ultimately used as a carpet underlay for cushioning. It is again
noted that any colored polyurethane product or colored polyol
composition may be produced with the inventive apparatus and carpet
underlay (as well as other foam articles) are the most
preferred.
BRIEF DESCRIPTION OF THE DRAWINGS
27. As FIGS. 1 and 2 were fully discussed above and are not part of
the preferred embodiment for this invention, the remaining drawings
shall be the only ones discussed in this section.
28. FIG. 3 is a schematic cross section of the preferred manifold
on which three valve assemblies are disposed in a radial
configuration.
29. FIG. 4 is a schematic cross section of the preferred spherical
ball valve sliced through its y-axis.
30. FIG. 5 is a schematic cross section of the preferred valve
assembly.
31. FIG. 6 is a side-view diagram of the preferred coloring
mechanism and procedure utilizing the preferred valve disposed on
the outside of the manifold. Such a diagram only exhibits two valve
assemblies due to the difficulty in drawing the accompanying
machinery and feed lines with more than two valves to be disposed
on the manifold. In actuality, three such valves (and accompanying
machinery) are preferred as is presented in FIG. 3, above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS INCLUDING THE
DRAWINGS
32. The manifold 24 in FIG. 3, is cylindrical in shape. Three valve
assemblies 26a, 26b, 26c are arranged radially around the
circumference of the manifold 24 which introduce colorant at
injection points 34a, 34b, 34c, which are located at positions well
inside the manifold 24 [here about 1 centimeter, but possibly from
about 5 millimeters and up a distance equal to the radius of the
manifold 24, if there is only one valve assembly present on the
manifold or if a plurality of valve assemblies are present and
configured serially (as in FIG. 1, discussed above); standard
manifolds are about 2 inches in diameter, having thus a 1-inch
radius] into the binder composition stream within the manifold 24.
Preferably, the inside surface of the manifold is coated with a
non-stick coating, such as polytetrafluoroethane (Teflon.RTM.) in
order to reduce the build-up or stagnation of colorant and binder
composition within the manifold 24. This reduces the potentially
deleterious effects attributed to laminar flow of the colorant and
binder. In particular, the non-stick coating is at least applied at
the actual injection points 34a, 34b, 34c for the colorants. The
valve assemblies 26a, 26b, 26c each comprise motors 28a, 28b, 28c
to drive the actuators 30a, 30b, 30c which move the individual
preferred spherical ball valves (not illustrated) between their
dispense and recirculation modes. The actuators 30a, 30b, 30c
comprise, as noted above, pins (not illustrated) which are attached
to the motors 28a, 28b, 28c and thus can be adjusted according to
the mode desired. The ball valve (not illustrated) thus may permit
the transfer of colorant to a recirculation line 36a, 36b, 36c for
reintroduction into a storage tank (not illustrated), which may
then transfer the colorant back into the valve assembly 26a, 26b,
26c for potential dispensing into the manifold 24. The dispense
line 32a, 32b, 32c thus leads to the manifold 24 and, through the
injector points 34a, 34b, 34c, the colorant is introduced into the
binder composition in the manifold 24. From the manifold 24 the
binder/colorant composition is then moved to a binder pump assembly
(not illustrated) for further mixing of the binder/colorant
composition, and subsequently to a spray assembly (not illustrated)
where the composition is sprayed onto, for instance, scrap foam, as
a substrate on which the binder/colorant composition ultimately
becomes polyurethane foam itself. The product thus is properly used
as a carpet underlay, exhibits even colorations throughout, and
does not exhibit any areas of "hardness" throughout the entire body
of the product.
33. The spherical ball valve 40 of FIG. 4, which may be made from
stainless steel (preferably), titanium, carbon steel, and the like,
comprises a first channel 42 which runs through the entire sphere
on one single axis (the x-axis, for instance) and at a specific
angle (such that the entire channel 42 is located at 0.degree. on
the x-axis). The ball valve 40 also comprises a second channel 44
which runs through the entire sphere which has a passage with an
entry port on the y-axis and a second entry port on the z-axis,
wherein the passage lies on the yz plane. Through this
configuration, and within a valve assembly (41 of FIG. 5), the
first channel 42 permits flow of the liquid colorant (not
illustrated) through the valve 40 to a recirculation feed line (58
of FIG. 5) when aligned with the inlet feed line (52 of FIG. 5)
from a storage tank (72a, 72b of FIG. 6). Upon rotation of
90.degree. by the utilization of a actuator pin (60 of FIG. 5)
attached to an actuator (62 of FIG. 5) engaged with a properly
shaped indentation (not illustrated) located at the point
270.degree. on the y-axis in and of the ball valve 40, the first
channel 42 is disengaged from all of its corresponding feed lines
(52, 58 of FIG. 5) and permits the flow of liquid colorant (such as
polymeric colorants, not illustrated) through the ball valve 40 (43
of FIG. 5) and into the dispensing feed line (64 of FIG. 5). The
bore of each channel 42, 44 is the same for each; however, the
actual size of both bores in said channels 42, 44 may be of any
size as long as they are the size as the bore of the inlet feed
line (52 of FIG. 5), the recirculation feed line (58 of FIG. 5),
and the dispensing feed line (64 of FIG. 5). The ball valve 40 (43
of FIG. 5) size is merely dependent upon the amount of space
between all of the feed lines (52, 58, 64 of FIG. 5) within the
entire valve assembly (41 of FIG. 5). The dispensing feed line (64
of FIG. 5) permits the flow of the liquid colorant (not
illustrated) into the manifold (24 of FIG. 3) through any type of
transferring means [such as, for example, an injector (not
illustrated)].
34. FIG. 6 thus incorporates a potentially preferred valve assembly
(41 of FIG. 5) into the entire polyurethane foam carpet underlay
coloring apparatus and procedure. The colorant is transported from
a storage tank 72a, 72b to at least one positive displacement spur
gear pump 74a, 74b on each feed line 85a, 85b coupled to a variable
speed motor/drive 76a, 76b (such as available from Viking). The
motor/pump combination 74a, 76a, 74b, 76b is run continuously in
either recirculation or dispense mode (depending on the position of
the 3-way valve 78a, 78b). In dispense mode, the colorant flows
through the valve 78a, 78b into a manifold 68. The throughput
pressure is measured through the utilization of a pressure gauge
84a, 84b attached to the feed line 85a, 85b from the pump 74a, 74b
to the 3-way valve 78a, 78b. The 3-way valve 78a, 78b is air
actuated (although any other type of actuator may be used) and
directs the flow of colorant from the recirculation feed line 86a,
86b to the dispense feed line to the manifold 68 when color flow to
the manifold 68 is desired. From the manifold 68, the
binder/colorant composition is moved to a binder pump 70 to mix the
composition thoroughly and then further on to a spraying assembly
(not illustrated) to spray the resultant colored binder composition
onto a substrate to form the target polyurethane foam composition
that can subsequently be cut into a carpet underlay article (not
illustrated). Such a carpet underlay (not illustrated) can then be
rolled and stored until unrolled and cut to conform to the shape of
a carpet piece (not illustrated). The carpet underlay (not
illustrated) can then be placed on a floor and the carpet piece
(not illustrated) may then be placed over the carpet underlay (not
illustrated) to provide cushioning, soft feel, durability, and the
like for the user.
35. There are, of course, many alternative embodiments and
modifications of the present invention which are intended to be
included within the spirit and scope of the following claims.
* * * * *