Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~Z09434
TITLE : DETERGE~T BAR PROCESSIN~
Field of the Invention
This invention relates to the processing of soap-
containing feedstocks to harden the soap bar product.
Background to the Invention
Soap bars are re~uired to have a hardness which
allows them to maintain their physical integrity during
manufacture, packing and use. A bar having a hardness
below the satisfactory level may deform and may be marked
by handling after manufacture.
Examples of bars which are liable to softness include
those having a high proportion of unsaturated feedstocks
eg, tallow, soya and palm, and those contain;n9
a relatively high level of water (ca 13% and higher). The
high level of water may be present to provide optimum
properties relating to another component. The present
invention achieves hardening of the soap material by
subjecting it to considerable working within a specific
temperature range in an efficient manner; the temperature
range being sensitive to composition.
General description
The present invention uses a device of the cavity
transfer mixer class to work the soap base. These devices
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comprise two closely spaced mutually displaceable surfaces
each having a pattern of cavities which overlap during
movement of surfaces so that material moved between the
surfaces traces a path through cavities alternately in each
surface so that the bulX of the material passes through the
shear zone in the material generated by displacement of the
surfaces.
Cavity transfer mixers are normally prepared with a
cylindrical geometry and in the preferred devices for this
process the cavities are arranged to yive constantly
available but changing pathways through the device during
mutual movement of the two surfaces. The devices having a
cylindrical geometry will comprise a stator within which is
journalled a rotor; the opposing faces of the stator and
rotor carry the cavities through which the material passes
during its passage through the device.
The device may also have a planar geometry in which
opposed plane surfaces having patterns of cavities would be
moved mutually, for example by rotation of one plane, so
that material introduced between the surfaces at the point
of rotation would move outwards and travel alternately
between cavities on each surface.
Another form of cylindrical geometry maintains the
inner cylinder stationary while rotating the outer
cylinder. The central stator is more easily cooled, or
heated if required, because the fluid connections can be
made in a simple manner; the e~ternal rotor can also be
cooled or heated in a simple manner. It is also
mechanically simpler to apply rotational energy to the
external body rather than the internal cylinder. Thus this
configuration has advantages in construction and use.
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~ aterial is forced through the mixer using
auxilliary equipment as the rotor is turned. Examples of
the auxilliary equipment are screw extruders and piston
rams. The auxiliary equipment is preferably operated
separately from the mixer so that the throughput and work
performed on it can be separately varied. The separate
operation may be achieved by arranging the auxiliary
equipment to provide material for processing at an angle to
the centre line of the shear-producing device. This
i~ arrangement allows rotational energy to be supplied to the
device producing shear around its centre line. An in-line
arrangement is more easily achieved when the external
member of the device is the rotor. Separate operation of
the device and auxiliary equipment assists in providing
control of the processing.
In general a variety of cavity shapes can be used,
for example Metal Box (UK 930 339) disclose longitudinal
slots in the two surfaces. The stator and rotor may carry
slots, for example six to twelve, spaced around their
periphery and extending along their whole length.
Preferably one or both surfaces are subjected to
. thermal control. The process allows efficient heating/
cooling of the material to be achieved.
Preferably the temperature of the material during
processing is in the range from about 30C to about 55C,
preferably up to 50C.
The soap feedstock may contain non-soap detergents
in amounts which would not interfere with the desired
effect. Examples of these actives are alkane sulphonates,
alcohol sulphates, alkyl benzene sulphonates, alkyl
sulphates, acyl isethionates, olefin sulphonates and
ethoxylated alcohols.-
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The processed feedstock was made into bar form usingstandard stamping machinery. Other product forms, eg
extruded particles (noodles) and beads can be prepared from
the feedstock.
s
Drawings:
The invention will be described with reference to
the accompanying diagrammatic drawings in which:
Figure 1 is a longitudinal section of a cavity
transfer mixer with cylindrical geometry:
Figure 2 is a transverse section along the line
II-II on Figure l;
Figure 3 illustrates the pattern of cavities in the
device of Figure l;
Figures 4, 5 and 7 illustrate other patterns of
cavities;
Figure 6 is a transverse section through a mixer
having grooves in the opposed surfaces of
the device;
Figure 8 is a longitudinal section of a cavity
transfer mixer in which the external
cylinder forms the rotor.
Specific description of devices
Embodiments of the devices will now be describ~d.
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A cavity transfer mixer is shown in Figure 1 in
longituainal section. This comprises a hollow cylindrical
stator member 1, a cylindrical rotor member 2 journalled
for rotation within the stator with a sliding fit, the
facing cylindrical surfaces of the rotor and stator
carrying respective pluralities of parallel,
circumferentially extending rows of cavities which are
disposed with:
a) the cavities in adjacent rows on the stator
circumferentially offset;
b) the cavities in adjacent rows on the rotor
circumferentially offset; and
c) the rows of cavities on the stator and rotor
axially offset.
The pattern of cavities carried on the stator 3 and
rotor 4 are illustrated on Figure 3. The cavities 3 on the
stator are shown hatched. $he overlap between patterns of
cavities 3, 4 is also shown in Figure 2. A liquid jacket
lA is provided for the application of temperature control
by the passage of heating or cooling water. A temperature
control conduit 2A is provided in the rotor.
The material passing through the device moves
through the cavities alternately on the opposing faces of
the stator and rotor. The cavities immediately behind
those shown in section are indicated by dotted profiles on
Figure 1 to allow the repeating pattern to be seen.
The material flow is divided between pairs of
adjacent cavities on the same rotor or stator face because
of the overlapping position of the cavity on the opposite
stator or rotor face.
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The whole or bulk of the material flow is subjected
to considerable working during its passage through the
shear zone generated by the mutual displacement of the
stator and rotor surfaces. The material is entrained for a
short period in each cavity during passage and thus one of
its velocity components is altered.
The mixer had a rotor radius of 2.54 cm with 36
hemispherical cavities (radius 0.9 cm) arranged in six rows
of six cavities. The internal surface of the stator
carried seven rows of six cavities to provide cavity
overlap at the entry and exit. The material to be worked
was injected into the device through channel 5, which
communicates with the annular space between the rotor and
stator, during operation by a screw extruder. The
material left the device through nozzle 6.
Figure 4 shows elongate cavities arranged in a
square pattern; these cavities have the sectional profile
of Figure 2. These cavities are aligned with their
longitudinal axis parallel to the longitudin~l a~is of the
device and the direction of movement of material through
the device; the latter is indicated by the arrow.
Figure 5 shows a pattern of cavities having the
dimensions and profile of those shown in Figures 1, 2
and 3. The cavities of Figure 5 are arranged in a square
pattern with each cavity being closely spaced from flow
adjacent cavities on the same surface. This pattern does
not provide as high a degree of overlap as given by the
pattern of Figure 3. The latter has each cavity closely
spaced to six cavities on the same surface, ie a hexagonal
pattern.
Figure 6 is a section of a cavity transfer mixer
having a rotor 7 rotatably positioned within the hollow
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stator 8 having an effective length of 10.7 cm and a
diameter of 2.54 cm. The rotor carried five parallel
grooves 9 of semi-circular cross section (diameter 5 mm)
equally spaced around the periphery and extending parallel
to the longitudinal axis along the length of the rotor.
The inner cylindrical surface of the stator 8 carried eight
grooves 10 of similar dimensions extending along its length
and parallel to the longitudinal axis. This embodiment,
utilised cavities extending along the length of the stator
and rotor without interruption. Temperature control jacket
and conduit were present.
Figure 7 shows a pattern of cavities wherein the
cavities on the rotor, shown hatched, and stator have a
larger dimension normal to the material flow: the latter
is indicated by an arrow. The cavities are thus elongate.
This embodiment provides a lower pressure drop over its
length compared with devices of similar geometry but not
having cavities positioned with a longer dimension normal,
i.e. perpendicular to the material flow. To obtain a
reduction in pressure drop at least one of the surfaces
must carry elongate cavities having their longer dimension
normal to the material flow.
The cavity transfer mixer of Figure 8 had the
external cylinder 11 journalled for rotation about central
shaft 12. Temperature control jacket 13 and conduit were
present but the latter is now shown because the cavities on
the central shaft are shown in plan view while the rotor is
sectioned. The central stator (diameter 52 mm) had three
rows 14 of three cavities with partial, i.e. half cavities
at the entry and exit points. On the rotor there were four
rows 15 of three cavities. The cavities on the stator and
rotor were elongate with a total arc dimension of 5.1 cm
normal to the material flow with hemispherical section ends
of 1.2 cm radius joined by a semicircular sectioned panel
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B.706
of the same radius. The cavities were arranged in the
pattern of Figure 7, i.e. with their long dimension normal
to material flow. The rotor was driven by a chain drive to
external toothed wheel 16.
Examples
Examples of the process of the invention will now be
given. The cavity transfer mixer illustrated in Figure 1
was used~
The mixer had a rotor radius of 2.54cm with 36
hemispherical cavities (radius 0.9cm) arranged in six rows
o six cavities. The internal surface of the stator
carried seven rows of six cavities to provide cavity
overlap at the entry and exit.
The temperatures used for processing the feedtocks
to provide the designed hardening will be dependant on the
composition used.
Example I
Tallow fat was saponified, washed, fitted and
vacuum dried to 20% moisture. The chips were then extruded
through the device with the aid of a soap plodder. The
hardness was measured with a SUR (Berlin) penetrometer
using a 9 conical needle under a total force of 200g for
10 seconds. Cooling water was applied to the stator and
rotor. The results are given in the Table I.
Example II
A soap feedstock comprising tallow 76% coconut 12%
and soya bean oil 12~ was prepared at a moisture content of
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16.5%. I'he feedstock was processed as in Example I and the
hardness measured.
Example III
A feedstock of tallow/coconut 80/20 was prepared and
the moisture increased to 18~ by cold milling additional
waterin. The feedstock was processed as in Example I and
the hardness measured.
Table I
Rotor Through- Penetration(mm) Temperature(C)
Example speed put Initial Final Inlet Outlet
(rpm) g min 1
I 95 290 5.2 4.2 36.0 42.0
II 95 380 4.8 4.2 42.0 43.0
III 120 520 4.3 3.7 32.0 47.0
The treatment of these feedstocks thus produced a
hardening of the bars.
Examples IV to VIII
These examples utilised a cavity transfer mixing
device with cavities of diameter 2.4 cm arranged
circumferentially.
Eight cavities on the stator and seven cavities plus
half cavities at each end on the rotor were present on the
components shown in Figure I. Water cooling was applied to
the stator and rotor. The formulations, which had a
relatively high water content and which contained
feedstocks providing physically soft bars, are given in
Table II. The results are quoted in Table III. The
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feedstock oils and fats are quoted as percentages of the
fat charge.
Table II
5 Example IV V VI VII VIII
Feedstock
Tallow 85 80 87.5
10 Babassu 10 15 7.5
Soya 5 5 5
Palm - - - 85
Palm kernel - - - 15
Hardened rice bran - - - - 42
15 Castor olein - - - - 42
Coconut - - - ~ 15
Rosin
Moisture 15 16.5 16 17 14
Tàble III
Rotor Through- Penetration(mm) Temperature(C)
Example speed put Initial Final Inlet Outlet
(rpm) g min
IV 30 200 2~7 1.6 29 43
V 30 280 2.6 1.9 29 50
VI 30 240 3.2 2.3 28 50
VII 30 260 2.9 2.0 29 50
30VIII 30 360 2.5 2.4 30 50
