Note: Descriptions are shown in the official language in which they were submitted.
;
lo 214
FIELD OF THE INVENTION
Mixing a fluid or plastic mass with modifying
agents, additives and the like to produce a homogeneous
material is customarily attempted by mixing apparatus which
is well known in the art and occurs in various forms.
Conventional extrude screw and barrel apparatus is employed
either separately or in conjunction with static flow dip
venting means. These conventional mixers and extrudes are
all shear dependent in that flow of plastic material may be-
come channelized with hotter, less viscous material tending
to run in channels along the central axis of the extrude
section and cooler, more viscous material tending to adhere
to extrude barrel portions at some points.
For example, with a conventional extrude screw
having 24 turns, only 80% of the material may be melted
by the first 12 turns, and the remaining 12 turns may
produce only a 95% melt. Periodically the more viscous
or unmelted material may become torn away from the barrel
and swept into the die in which forming is to take place.
To prevent this, more heating and pressure is often exerted
through the extrude screw with excessive use of energy and
undesirable increase in temperature of material in the barrel
which can degrade some portions of the material. Thus the
need exists for more complete melting and mixing which can
be carried at localized points to deal with these Defoe-
gullies and prevent lack of homogeneity in the molded product.
I;
~2~Z2~
SUMMARY OF THE INVENTION
The present invention relates to an improved
modular mixing apparatus and to improved methods of
processing a fluid or plastic mixture wherein inter-
changeable processing modes are employed.
It is a chief object of the invention to provide
improved methods and means for mixing fluid or plastic
bodies.
Another object of the invention is to devise a
modular mixing apparatus which combines a plurality of no-
toting shear ring means with a stationary sleeve element by
means of which luminary displacement of a fluid material is
achieved, then dispersed material is separated into spaced
apart streams of material, and the spaced apart streams are
. further subdivided.
Still another object of the invention is to
combine in a single rotating body a plurality of processing
modes which may be selectively employed in in interchangeable
relationship to one another to process fluid or plastic
bodies of varying characteristics.
Another object is to provide means for retrofitting
an extrude screw where an appreciable percentage of rota-
lively viscous or unmelted characteristics resists mixing
and blending and requires intensive extrude processing.
It has been determined that the foregoing objectives
may be realized by luminary displacement of a fluid mass which
is thereafter guided along undulating linear paths of travel
of relatively short axial length, which material thereafter
undergoes further luminary displacement.
--3--
I 2 21
The combined effect of luminary displacement of
fluid material followed by traveling the displaced ma-
tonal along undulating linear paths of short axial length
and to undergo further luminary displacement, operates to
achieve a high degree of intimate mixing and blending by
which substantially all material in the fluid mass which
is not in a fluid state is converted into a part of a
homogeneous product.
I I
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an elevation Al view illustrating a
basic component assembly of one desirable form of modular
extrude apparatus of the invention combined with an ox-
truer barrel which is shown fragmentarily.
Figure 2 is a diagrammatic view of conventional
plastic processing apparatus including an extrude screw,
an extrude barrel and portions of a dye shown in cross
section with which a modular mixing apparatus of the in-
mention is combined.
Figure 3 is a cross section taken on the line
3-3 of Figure 2.
Figure 4 is an exploded view showing in further
detail the component parts of the modular extrude apparatus
shown in Figures 2 and 3.
Figure 5 is a cross section taken on the line 5-5
of Figure 3.
Figure 6 is a cross section taken on the e 6-6
of Figure 3.
Figure 7 is a cross section taken on the line 7-7
of Figure 3.
Figure 8 is a cross section taken on the line 8-8
of Figure 3.
Figure 9 is a cross section taken on the line 9-9
of Figure 3.
Figure 10 is an end elevation Al view showing a
dispersing tip element in the modular mixing apparatus.
Figure 11 is a fragmentary perspective view showing
the component parts of the mixing apparatus of Figures 2
and 3 and indicating portions of a barrel member having
been broken away to indicate by arrows a changing flow of
material along undulating paths of travel of short axial length.
--5--
i;2~2X~
Figure 12 is a fragmentary cross-sectional view
showing portions of the mixing apparatus and indicating
rotational direction of the various modules.
Figure 13 is a cross sectional view taken on the
line 13-13 of Figure 12 illustrating diagrammatically one
path of flow of fluid material.
Figure 14 is another view taken on the line 14-14
of Figure 12
Figures 15, 16, 17, 18, 19 and 20 are additional
views similar to Figure 13 but taken on respective cross
sectional lines 15-15, 16-16, 17-17, 18-18, 19-19 and
20-20.
Figure 21 is a fragmentary cross sectional view
of a modified form of mixing apparatus of the invention
and particularly showing the combination of kneading block
apparatus combined with the rotating screw driver shaft.
Figure 22 is a fragmentary cross sectional view
of a barrel member showing mixing apparatus of the no
mention corresponding to the assembly shown in Figure 21.
Figure 23 is a cross section taken on the line
23-23 of Figure 22.
. ~Z~2Zl~
DETAILED DESCRIPTION OF THE INVENTION
= _ = . _ . .
In general the modular mixing apparatus of
the invention includes: (1) a main shaft which is en-
gaged with a threaded end of an extrude screw and no-
taxable therewith, (2) spaced apart shear ring elements notable
with the shaft, and (3) a stationary shearing control sleeve
which is located between the shear ring elements,
disposed around the driver shaft, and fixed to an outer ox-
truer barrel component of the apparatus.
This basic component assembly is made use of to
carry out multi-stage mixing in a rapid and unique manner.
A helically moving fluid body in an extrude screw and
barrel apparatus is brought into contact with rotating
shear ring means to undergo luminary displacement; it is then
guided through a stationary shearing control sleeve along
undulating linear paths of travel of relatively short axial
length; and thereafter undergoes further luminary displacement
by shear ring means.
Referring in more detail to the Figures shown in
the drawings, Figure 1 illustrates the modular mixing
apparatus of the invention in one basic form. Figures 2-23
illustrate other modular mixing apparatus having various
processing means combined in one form or another with a
basic component assembly of parts 1, 2, 3, and lay
--7--
~2~L2~1~
The apparatus of Figure 2 may, for example, be
supported on a bed plate P and movie include a feed section
having a hopper H into which plastic material is furnished
in the usual manner to an extrude screw S received within
a barrel B and power driven through a reduction gearing R
by a motor M. T denotes thermal control means in commune-
cation with the extrude barrel B.
It is customary to construct extrude screws
such as the screw S with a predetermined length to diameter
ratio. As shown in Figure 2 diagrammatically, screw S may
have a length which is twenty times the diameter of the
screw S including a feed section of five diameters, a
transition section of seven diameters, a metering section
of six diameters and a mixing section of two diameters.
In this mixing section of two diameters is lo-
acted the modular mixing apparatus of the invention and
it should be understood that this modular mixing apparatus
as hereinafter described in detail may be combined with an
extrude screw having a length of 18 diameters or other
lengths as an original construction. However, where it
is desired to modify a screw having some given length such
as a length of 20 diameters, or some other number of die-
meters, the screw may be cut to a length of 18 diameters,
for example, and then retrofitted with the modular mixing
apparatus of the invention by internally threading the
cult off end of the screw S and attaching a reduced threaded
end of the invention mixer apparatus therein.
l~lZ;Z
Considering in further detail the basic component
assembly shown in Figure ]., numeral l denotes a main shalt
having a reduced threaded extremity lo which is securely
engaged in an internally threaded end of screw S. An opt
posit end of main shaft 1 has integrally formed therewith shear ring portion lo. Located around shalt 1 in spaced
relation thereto is a stationary shear control sleeve 2.
This sleeve 2 is fixed against an inner peripheral surface
of the barrel B. This may be accomplished, for example, by
lo forming sleeve 2 of a metal having a coefficient of expansion
greater than the coefficient of expansion of the petal in
barrel B.
Sleeve 2 is also positioned with one end in abutting
relation to the shear ring portion lo. At an opposite end
of sleeve Andy in abutting relationship therewith is a
separately formed shear ring element 3 which is solidly
secured between the extrude screw S and an annular shoulder
portion lo of shaft 1 and is rotatable therewith.
This basic component assembly including the main
shaft l, sleeve 2 and shear ring means and lo is also
shown in Figures 2, 3 and 4 combined with other modular
components for another processing mode and is still further
shown in Figures 21-23 combined with different component
means and still other processing modes.
It will be understood that opposite ends of the
stationary sleeve 2 will be subjected to wear when the shear
ring portions lo and separately formed shear ring 3 are being
rotated by main shaft 1. To prevent such wear the sleeve
2, in one preferred embodiment, may have opposite ends :
thereof provided with hardened bearing portions as PA and
2B.
ZZl~
Extending inwardly of sleeve 2 and downwardly
from the hardened bearing-portions 2B is a conical surface
2C. Similarly, extending inwardly and downwardly from
bearing PA is another conical surface ED. These conical
surfaces are formed to provide for controlling the thick-
news of luminary displacement carried out by movement of
the shear ring 3 and shear ring portion lo. Increasing
or decreasing the depth of these conical surfaces varies
the thickness of each luminary cut off by a blade and
provides a desirable range of thickness controlled.
As noted above, the sleeve 2 has an inner port-
furl surface occurring in spaced relation to the main
shaft 1 and this inner peripheral surface is further con-
strutted with spaced apart axially extending grooves as 2G,
more clearly shown in Figures 4 and 9. These grooves function
to receive sheared portions of fluid material cut of by the
shearing blades and to provide for a plurality of streams of
materiel being diverted and guided along a plurality of
linear paths of travel between the sleeve and the shaft 1.
An important feature of the invention is the come
bination of a stationary sleeve having conical shear con-
trot surfaces and flow diverting grooves as described above
with spaced apart shear ring means of a unique construction.
Thus, the shear ring 3 is formed with radially
extending shearing blades as PA, 3B, 3C, etc. These shearing
blades are spaced apart to provide passageways through which
extruded material may pass. Extending between the blades
PA, 3B, 3C, etc. are inwardly inclined sloping surfaces as
ED, YE, OF, etc. Similarly, the shear ring portion lo is
formed with radially extending shearing blades as lo, if, lo,
-10--
Sue
etc. and are spaced apart to provide passageways for fluid
flow and extending between the blades are sloping surfaces
lug, lo, lit etc. which are inclined upwardly, as shown more
clearly in Figures 4 and 11, The arrangement of parts of
Figures 4 and if is also shown diagrammatically in Figure
12.
As a result of this arrangement of parts there
is realized periodically undulating flow of material which
is successively interrupted to undergo luminary displacement
and thereby an intensified mixing is achieved. This in-
tensified mixing is highly effective in subdividing material
which is not in a fluid state and which may tend to accumu-
late at points near the end of an extrude screw as indicated
in Figure 2.
In operating the apparatus of Figure l a helically
moving extruded mass of fluid material is advanced through
the extrude barrel B by the extrude screw S and portions
of the helically moving mass move into the spaces between
the blades of-shear ring 3. Figure 13 illustrates the port
lions of material in diagrammatic form.
Immediately thereafter these portions of material
are subjected to luminary displacement. The thickness of each
of the laminate displaced is regulated by the depth of the
conical surface ED of sleeve 2.
Thereafter, the displaced material becomes guided
along grooved surfaces of sleeve 2 as spaced apart streams
of material which travel in linear paths of relatively short
axial length. Figure 14 shows diagrammatically these swoop
crated streams of material denoted by reference characters
Ml, My, My, My, My and My.
-11--
SLY
Thereafter, the streams of material are con-
tenuously subdivided by a second stage of luminary disk
placement carried out by shear ring portion lo. Figure
15 indicates diagrammatically flow of displaced maternal
My.
Portions of material thus subdivided is merged
together in a helically moving mass My as suggested die-
grammatically in Figure 16 and quickly undergoes another
step of luminary displacement by shear ring 7 as indicated
diagra~natically by portions of material MY in Figure 17.
In the processing mode illustrated in Figure 1
the metering module 4 discharges the finally mixed and
blended product described which is shown for example at
the end of the apparatus illustrated in Figure 2.
In Figure 4 there is illustrated a processing
mode by means of which increased shearing and mixing may
be carried out depending upon the material being dealt
with. In this modular mixing apparatus the same component
assembly is employed including the main shaft 1, sleeve 2
and shear ring means 3 and lo.
However, in place of the metering screw 4 there
is attached another shear ring member 7 having a threaded
end 7' which is threaded into the internally wormed threads
of ring portion lo to become rotatable therewith. the
member 7 is formed with internally constructed threads as
OH and have outwardly projecting shearing blades as AYE,
12B, 12C, etc. These blades, unlike the blades of ring
portion lay are not parallel to the central axis of the
extrude screw but are skewed and extend angularly with no-
spent to the central longitudinal axis of the ring 7.
-12-
lZ~Zl'~
It has been found that an acceleration
flow of material may be realized by these angularly disk
posed blades. Also, desirable results may be obtained
by combining these shearing blades with another sleeve
member 6 to carry out a progressively extended stage of
shearing as member 7 is rotated around the end of the
sleeve 6 which has hardened the bearing portions as PA
and 6B earlier described. It will also be noted that the
thickness of luminary displacement of fluid material is
again regulated by conical surfaces as ED.
Still another stage of shearing is obtained
by the use of a diffuser tip 5 which has spaced apart
shearing blades rotatable around the sleeve 6. The
member 5 is formed with a threaded end YE which is de-
teachably secured in threaded relationship with member Thea member 5 is also shaped with a conical end face and
material passing through the openings denoted by arrow
5 in the extrude tip tend to be forced along converging
paths of travel for desirable communication with the
die member.
Material passing through the blades of shear
ring 7 again enter a the stationary sleeve 6 and quickly
undergo another step of luminary displacement by shear
ring 7 and become guided along the grooved surfaces of
the stationary sleeve 6 to provide spaced apart streams
as suggested diagrammatically in Figure 18 and diluted
by the reference characters My, My, My, Moo, MU and M12.
lZ~f~ I
A final step of luminary displacement to sub-
divide these streams of material is carried out by move-
mint of the dispersing tip 5 against the stationary sleeve
6 and this provides portions as MY indicated diagrammatic
gaily in Figure 19. A resulting mixture MY is then led through the dispersing tip and leaves the tip as a con-
verging stream indicated by the arrows in Figure 20. In
Figure 21 another mode of mixing has been illustrated in
which there is employed the same basic component assembly
including parts 1, 2, 3, and lo; however in place of the
second shear ring 7 there is mounted in the threaded end
of shear ring lo a kneading rotor denoted by numeral 8
which is rotatable against the stationary sleeve 6, as
shown in Figures 21, 22 and 23. The kneading rotor come
potent 8 is formed with a threaded end PA and is provided
with internal threads 8B.- It will be noted that the
kneading rotor is constructed with oblong shaped bars or
arms which extend radially outward and occur in angularly
disposed relationship with respect to one another, as
shown in Figures 4, 21, 22 and 23. It has been found
that a kneading and and stretching of some fluid masses
at this point in the processing can be carried out to
provide further desirable attenuation and mixing of certain
fluid materials.
-14-
