Apparatus for producing striated soap bars of comparable aesthetic quality on both inner and outer log faces for soap bars produced in a dual extrusion process

The present invention provides a novel eyeplate apparatus which permits logs to be extruded in a dual extrusion process whereby the aesthetic quality of the inner and outer log faces of the extruded logs is comparable. In a preferred embodiment, the eyeplate is used in combination with upper and lower eyeplate baffles in the nosecone of a plodder.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a novel apparatus used in a dual extrusion 
process for the preparation of soap which apparatus permits the production 
of soap bars having comparable aesthetic quality on both the inner and 
outer face of the soap log. In particular, the invention relates to the 
use of a novel eyeplate in the dual extrusion process providing the 
above-described benefits. The invention further relates to a novel process 
for producing soap bars in a dual extrusion process wherein both faces of 
the bar have comparable aesthetic quality and which process comprises the 
use of the novel eyeplate. 
In a preferred embodiment of the invention, the novel eyeplate is used in 
combination with upper and lower eyeplate baffles in the nosecone of a 
plodder. 
2. Background 
Striated soap has apparently become very popular with the consumer due to 
the aesthetics of the soap. 
Due to limitations imposed by the Federal Drug Administration (FDA) in 1976 
on the type of coloring system which can be used in the preparation of 
soap, it has proved very difficult to obtain desired striation aesthetics. 
Specifically, using the colors which are required under FDA regulations, 
the color mix has a tendency with time to blend throughout the bar 
(thereby reducing the contrast between the striation and the rest of the 
soap) and thus reduce the aesthetic quality of the soap. In addition, it 
has been found that striated soap smears when passed through an orifice 
plate of an extruder. 
Striated or variegated soap may be produced in various ways. Colored liquid 
may be mixed with soap filaments in a worm plodder prior to extrusion of 
the billet as is taught in U.S. Pat. No. 3,485,905 to Compa et al. It has 
also been disclosed to make variegated soap by introducing colored liquid 
through the worm of a plodder as described in U.S. Pat. No. 3,676,538. It 
has further been proposed to make variegated soap by bringing together 
differently colored soaps from separate plodders or the like in a mixing 
device which extrudes the mixture as a continuous billet. In all of these 
devices, a soap billet of generally rectangular cross-section is extruded 
from the cone of the final plodder. 
It has been observed that the color at the surface of the billets of most 
variegated soaps extruded from plodders is usually diffused and the 
striations indistinct at the surface. This problem has become even more 
acute since the FDA restrictions discussed above on the type of coloring 
systems which can be used during preparation of the soap. 
In order to highlight the striations, a number of solutions have been 
suggested by the art. 
U.S. Pat. No. 3,485,905 to Compa describes a process in which filaments of 
soap are compacted and forced by a rotating worm in a cylinder through a 
nozzle which preferably has attached cutting edges to shave-off 1/32 to 
1/16 of an inch of the surface as the bar is extruded through the nozzle. 
There is no discussion of the flow pattern of soap through the plodder or 
nosecone and no mention of an eyeplate with a relief system for 
controlling the flow of soap or the effect on the aesthetics of the soap 
bar the flow pattern may have. 
U.S. Pat. No. 3,857,662 to Ratz teaches a process and apparatus for 
producing striated soap in which soap is extruded as side by side billets 
through a die having closely spaced openings corresponding to the billet 
cross sections. The die further has slots adjacent to the outer sides of 
the openings for shaving away outer surface layers. In this patent, a 
narrow land 18 is used to separate the billets. This narrow land has no 
opening or port through which soap can flow to provide relief in the flow 
pattern when the billets are extruded through openings in the middle. 
There is no discussion or appreciation of what effect a relief in the flow 
pattern may have on the aesthetics of the log, particularly on the inner 
faces of the logs. 
U.S. Pat. No. 3,784,533 to Mach teaches a method and apparatus in which 
soap is first extruded through a nozzle having an opening and then glossed 
as it passes through the opening in order to impart gloss. Again, there is 
no orifice or port in the middle where the soap is extruded into two or 
more bars and no recognition of how such an orifice might affect flow 
patterns and the aesthetics of the inner log face. 
U.S. Pat. No. 3,868,208 to Fischer teaches a nozzle plate assembly for 
obtaining an improved surface finish on high speed extrusions without 
requiring trimming. 
In none of these references is there provided an apparatus or method for 
overcoming the problem of two perceptibly different surface patterns 
between inner and outer log faces which is a well known phenomenon that is 
typically associated with striated soap produced in conventional dual 
extrusion processes. 
Thus, it would be greatly desirable to find an apparatus or method which 
could overcome the problem of different surface patterns produced in dual 
extrusion processes and which could produce bars with clearly defined and 
comparable surface patterns on both the inner and outer log surfaces. 
SUMMARY OF THE INVENTION 
Applicants have now found an apparatus and a method which overcomes the 
problem of perceptibly different surface patterns on inner and outer log 
faces of soap bars produced in a dual extrusion process. 
In particular, the present invention provides a novel eyeplate which 
comprises two or more extrusion outlets for forming striated logs and 
three or more extrusion relief outlets for relieving and equalizing the 
surface drag (caused by the flow of the soap through the plodder) on the 
dual extruded log's inner and outer surface. Two extrusion relief outlets 
are located on the eyeplate on the outside of the log extrusion outlets 
and one relief outlet is found between the two log extrusion outlets. 
The relief outlets comprise plates which are inserted into a generally 
rectangular plate holding the relief plates. The generally rectangular 
plate holding the relief outlet plates (which also define the extrusion 
outlets) is designed so that it can be readily removed and inserted into 
the generally cylindrical eyeplate. In this manner, different rectangular 
plates containing different number of relief outlet plates can be readily 
interchanged. 
The relief outlet plates are defined by a generally longitudinal port o 
orifice in the center of the plate running generally along the entire 
length of the plate and into which soap flows and is then extruded as a 
convoluted and flexible soap ribbon which may be recycled or discarded. 
The plate is tapered from the outer edges on both sides into the middle 
such that the central opening is recessed and the soap flow first hits the 
outer ends of the plate and slopes downwardly towards the center as is 
schematically shown in FIG. 5. 
This feature provides even further relief which, while applicants do not 
wish to be bound by theory, applicants believe to be the reason behind the 
improved aesthetics found in the log faces. 
In a preferred embodiment of the invention the wall of the relief plate 
forming the relief outlet through which the soap passes are alternately 
tapered and straight so that the soap which is extruded from the relief 
outlet is flexible and not rigid. The flexibility in the soap ribbon is 
preferred to enhance the efficiency of the rework conveying operation. 
In another preferred embodiment of the invention, upper and lower eyeplate 
baffles are provided in the nosecone of the plodder to effect a change in 
the soap flow from a cylindrical to a rectangular and horizontal 
cross-section. This change in flow pattern together with the perpendicular 
position of all the extrusion outlets on the eyeplate is believed to even 
further provide well defined striations on both the inner and outer log 
faces of bars extruded through this dual extrusion process. 
The baffles are designed to be an integral part of the eyeplate and are 
generally attached to the plate with screws (although it is possible to 
design a one-piece eyeplate with baffles affixed). When upper and lower 
plate baffles are used, it is also not required that the eyeplate 
apparatus contain a middle relief between the two extrusion outlets.

DETAILED DESCRIPTION OF THE INVENTION 
The subject invention provides a novel apparatus whereby soap can be 
extruded in a dual-extrusion process to produce a bar of comparable 
aesthetic quality on both inner and outer log faces of the extruded bars. 
While not wishing to be bound by theory, it is believed that the enhanced 
aesthetic effect results from a reduction in the drag flow of the soap as 
it passes from the nosecone of the plodder to the eyeplate. In turn, this 
reduced drag is believed to be produced by a novel eyeplate in which at 
least three extrusion relief outlets are provided and, in particular, one 
extrusion relief outlet between the two log extrusion outlets. 
In a preferred embodiment of the invention, the plates defining the relief 
outlets are designed so that the outer edges of the plate (that is edges 
removed from the central orifice or port) protrude furthest out to the 
flow of soap coming from the cone towards the eyeplate and are first to 
come into contact with the soap. The relief plates are tapered so that the 
plate slopes downwardly inwardly to the center portal which is furthest 
from the flow. Thus, the outer edges of the plate act as a "mini-baffle" 
to further regulate fluid flow and reduce drag as the soap approaches the 
eyeplate. This is graphically demonstrated by FIG. 5. 
In another preferred embodiment of the invention, eye plate baffles are 
located strategically outside the eyeplate again to affect fluid flow and 
reduce drag as the soap approaches the eyeplate. When eyeplate baffles are 
used, it is not required that a middle relief outlet be used. 
The baffles form an integral part of the eyeplate and are preferably 
attached to the eyeplate with screws. Of course, it is possible to form a 
one-piece plate in which the baffles are affixed to the eyeplate. The 
baffles are located at the end of the nosecone in a fixed position to the 
inside wall of the dual extrusion eyeplate. 
The dimensions of the baffles are not critical and will depend on the size 
of the cone and the length of the cone. The only design requirement is 
that the baffles be sufficiently large that they effect the flow pattern 
from the cylindrical flow of the nosecone to a horizontal flow pattern. 
In another preferred embodiment of the invention the walls defining either 
side of the portal in the relief outlets are designed to be alternately 
tapered and straight such that the soap coming through is extruded into a 
flexible convoluted soap ribbon form. The convoluted form is preferable to 
the straight soap ribbon for efficiently enhancing the rework stream 
conveying operations. 
Another aspect of the invention is the fact that both the size of the 
relief outlets (that is, the outside extrusion relief outlets) and the 
size of the log extrusion outlets can be controlled. In addition, while 
not contemplated as part of the process of the subject invention, the 
central relief plate may be removed altogether and the eyeplate of the 
invention can also be used in a single extrusion process. Further, the 
relief plates are also designed to be inserted or removed from a generally 
rectangular-shaped plate and it is another aspect of the invention that 
the generally rectangular-shaped plate can be readily inserted or removed 
from the generally cylindrically-shaped eyeplate. 
Referring now to FIG. 1, this figure shows a conventional soap extruder or 
plodder 10 which comprises a helical screw 11 driven by of a suitable 
motor not shown in the figure. The soap mass containing the striating 
agent is compacted through plodder 10 towards a downstream coned end 12. 
The soap then flows out through the extrusion plate apparatus 13. In this 
preferred embodiment, eyeplate baffles 14 and 15 are strategically located 
just upstream of the extrusion plate apparatus 13. In this preferred 
embodiment of the invention, the eyeplate baffles are used to form and 
channel a horizontal soap stream through the perpendicular extrusion posts 
in the eyeplate. It is believed that the relationship of the horizontal 
soap stream passing through the generally rectangular extrusion posts 
further improves the aesthetic effects observable in the soap bars of the 
invention. 
FIG. 2 represents a frontal view of the extrusion plate apparatus 13 at the 
end of the plodder nosecone 12 shown in FIG. 1. 
According to this preferred embodiment of the invention, the eyeplate is 
constructed such that three plates are inserted into a central open area 
(defined by a generally rectangular-shaped plate 50 which can be readily 
inserted or removed). The three relief plates define two log extrusion 
outlets 15 and 16 and at least three relief outlets 17, 18 and 19 (each 
relief plate comprising one relief outlet). As indicated, the relief 
outlets or portals 17, 18 and 19 are defined by column-like plates having 
slots or outlets (17, 18 and 19) running the length of the column-like 
plates from top to bottom. In the central plate defined by sides 20 and 
20a, the outlet 18 is generally not adjustable although it is possible 
that a column-like plate could be designed such that two sides of the 
plate 20 and 20a slide apart to adjust the outlet. 
It should also be appreciated that, while the figures depict generally 
rectangular shaped extrusion orifices (e.g., 15 and 16), the extrusion 
orifice may be designed to be generally cylindrical in shape or any other 
shape which may be known in the art. 
Also, while according to the process of the invention the central plate 
defining portal 18 should be present to provide relief in the center and 
thereby provide enhanced aesthetics, it will be appreciated that the 
eyeplate is designed such that the central plate may be removed entirely 
from the generally rectangular-shaped plate 50 and a single extrusion 
process may be used. 
When the central relief plate is present, one side of the relief plate 
(e.g. 20a) and the outside of a second relief plate (e.g. 22), which 
second relief plate is attached to the side of the generally rectangular 
shaped plate, together define one log extrusion outlet (e.g. 15) while the 
other side of the central relief plate (e.g. 20) and the outside of a 
third relief plate (e.g. 21), which third plate is attached to the 
opposite side of the generally rectangular shaped plate, together define 
the second log extrusion outlet (e.g. 16). 
As best viewed from FIG. 3, 22 is only one portion of the outside relief 
plate while the rest of the relief plate is defined by portion 22a. 
Similarly 21 is only one portion of the other outside relief plate while 
the rest of the relief plate is defined by portion 21a. 
Thus, portion 22 defines both the outside of the log extrusion outlet, as 
well as one side of the outside relief plate. The other side of the 
outside relief plate is defined by an adjustable extrusion relief control 
panel 24. Similarly, 21 defines not only the outside of one of the log 
extrusion outlets, but also defines one side of the other outside relief 
plate. The other side of the second outside relief plate is defined by an 
adjustable extrusion relief control panel 23. Adjustable extrusion relief 
control panels 23 and 24 can be adjusted to control the size of the 
extrusion relief outlets 17 and 19 on the sides of the eyeplate. 
While the eyeplate apparatus has been described above to exemplify a dual 
extrusion process, it will be appreciated by one of skill in the art that 
more than one column-like plate (defined by 20 and 20a in FIG. 2) may be 
inserted into the generally rectangular-shaped plate such that three logs 
or more might be extruded. 
It will be appreciated from FIG. 2 that in addition to adjusting the relief 
outlets via adjustable extrusion relief control panels 23 and 24 (shown in 
FIG. 3), the size of the log extrusion may also be controlled using log 
weight adjusting screws 30 and 31. 
In the relief plate, (e.g. 20 and 20a of FIG. 2) two-headed arrows defining 
the width of the relief plate walls can be observed. The walls are tapered 
to gradually slope inward from the outside edges such that the outside 
edges are furthest away from outlet 18 and jut out the furthest while the 
inside edges approximate to the outlet are furthest in. Since the flow of 
soap flows in a plane perpendicular to the figure, it will be appreciated 
that the soap will first hit the highest protuberance (defined by the 
outside edges of the relief plate wall) and then curve in towards the 
center. While not wishing to be bound by theory, it is believed the 
tapering wall will help further reduce drag and establish the eve flow 
which accounts for the enhanced and even striations of the invention. 
The angle of the slope is not critical and depends in part on the width of 
the column-type piece. 
It can also be seen from FIG. 2, that the outside edges of the wall 28 and 
29 (which are also the sides which protrude out the furthest) also may 
have a certain width. This width serves to control the level of eyeplate 
surface contact or drag on the extruded log. This width is generally 
designed to be about 1/16 of an inch although it may vary widely, for 
example, from about 1/64 of an inch to 1/2 inch. The greater the width, 
the more drag and the broader the stripe which will form on the log. 
Conversely, the shorter the width, the less drag and the thinner the 
stripe on the soap. 
The orifice of the relief plate may also vary in width although it is 
generally preferred that the width vary from about 1/32 inch to 1/2 inch, 
preferably 1/8 inch. In practice it is preferred that the width not be 
smaller than 1/8 inch and the smaller the width the less sharp will be the 
stripes on the soap. 
Finally, from FIG. 2 can also be seen a view of the upper plate baffle 35 
and lower plate baffle 36 which, in a preferred embodiment of the 
invention, helps to direct soap flow as the soap approaches the eyeplate 
and helps enhance evenly distributed striation even further. 
FIG. 3 is a section elevation view of FIG. 2 setting out in greater detail 
some of the eyeplate components defined in FIG. 2. 
Central column-like relief plate defined by 20 and 20a can be seen in FIG. 
3. From this figure, the slope of the plate defined by the double-headed 
arrows in FIG. 2 (sloping from the outside edges 28 and 29 to the central 
outlet 18) can also be seen. 
In a preferred embodiment of the invention, the walls defining each of the 
extrusion relief outlets are made alternatively tapered and straight such 
that the soap ribbon which passes through the walls comes out flexible and 
structurally fragile to facilitate recycling to the rework station. This 
can be seen both from FIG. 2 where 40 and 42 represent the tapered part of 
the wall and 41 represents the straight part; and from FIG. 4 where 40 
again represents a tapering part of the wall at the orifice and 41 again 
represents a straight part. 
Finally, in another aspect of the invention, all relief plates (and the 
extrusion outlets they define) can be readily inserted or removed from a 
generally rectangular-shaped plate 50 which plate in turn can be readily 
inserted or removed from the eyeplate. 
OPERATION OF THE APATUS 
In operation, the compacted plastic soap mass containing the striating 
agent is converted from a circular to a rectangular cross sectional shape 
by the upper and lower baffles prior to being forced through the ports 
(generally 5 ports) of the extrusion apparatus. Two of the ports serve to 
form the striated logs and the remaining serve to equalize and relieve the 
level of surface drag on the extruding logs' inner and outer faces. 
As indicated above, the apparatus of this invention results in a striated 
bar which has a comparable aesthetic quality on both outer and inner log 
faces when used in a dual extrusion process. 
More specifically, in a side by side comparison of bars where relief 
outlets were used relative to bars where no relief outlets were used, 
those bars where relief patterns were used displayed clearly superior 
striation patterns relative to the bar formed with no relief. When a 
middle relief outlet was used in addition to the two side relief outlets, 
even more enhanced striation was observed. 
In another embodiment of the invention, the invention relates to a process 
for providing comparable aesthetic quality on both inner and outer log 
faces wherein the process involves the use of the novel apparatus.