Note: Descriptions are shown in the official language in which they were submitted.
12~9436
B.709
TITLE : DETERGENT BAR PROCESSING
Field of the Invention
This invention relates to the processing of soap
feedstocks to introduce volatile components, for example
perfumes.
Background to the Invention
When processing soap feedstocks a usual requirement
is to introduce a perfume to provide a fragrance for the
product. It may also be desirable for some products to
incorporate another class of volatile material, eg a
solvent during processing. The efficiency of incorporation
will depend on a number of factors including processing
temperatures, and times, and communication with the
atmosphere.
General description
It has been found a cavity transfer mixer provides
an efficient route for incorporation because the processing
temperatures are maintained, in general, below those
usually encountered in soap processing. The processing
time is low and the mixing occurs in an enclosed volume.
The energy required will normally be lower than that
required in conventional processes.
33E2lE
9436
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The present invention uses a device of the cavity
transfer mixer class to introduce a volatile component into
the soap base. These devices comprise two closely spaced
mutually displaceable surfaces each havin~ a patter~ 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 bulk 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 give constantly -
available but changing ways path throuqh 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 temperature of processing is preferably from about
30C to about 55C, more preferably below about 40C.
The device may also have a planar geometry in which
opposed plane surfaces having patterns of cavities would be
o 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 external 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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Material 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 ~ork
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
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 materials to be achieved.
The detergent 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.
The processed feedstock was made into bar form using
standard stamping machinery. Other product forms, eg
lZ0943~,
B.709
extruded particles (noodles) and beads can be prepared from
the feedstock.
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 1:
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 described.
A cavity transfer mixer is shown in Figure 1 in
longitudinal 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
lZG9436
- 5 - B.709
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. The 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.
The whole or bulk of the material flow is subjected
3~ to considerable working during its passage through the
shear zone generated by the mutual displacement of the
lZ(~9436
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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 longitudinal axis 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 8iX 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
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)
lZ~9436
B.709
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 embcdiment 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 10w.
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
of the same radius. The cavities were arranged in the
pattern of Figure 7, i.e. with their long dimension normal
lZ(~9436
- 8 - B.709
to material flow. The rotor was driven by a chain drive to
external toothed wheel 16.
Examples of the process of the invention will now be
given.
Example I
The mixer used the cavity pattern of Figure 3 and
had a rotor radius of 2.54cm with 36 hemispherical cavities
(radius 0.9cm) 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.
A tallow/coconut superfat feedstock (60/40/7~) was
prepared. 2-phenylethanol (1.0%) was added to this base in
a ribbon mixer to coat the noodles with this volatile
material. The base was divided with the first half being
treated in the cavity transfer extruder with the aid of a
soap plodder and the second being subjected to conventional
treatment. Tablets were stamped and analysed by gas
chromatography of the head space. Results showed less of
the volatile component was lost by the cavity transfer
mixer route.
Example II
A tallow/coconut (80/20) soap with a glycerol
content of 1.25% was used as base. Limonene (1.5% on base)
was added to a sample of soap in chip form and
conventionally processed.
A second sample was mixed with the same quantity of
limonene and passed through a device of Figure 1 having
cavities of diameter 2.4 cm arranged with six cavities in a
circumferential circle. The stator carried four complete
12(~9436
_ g _ B.709
cavities and the rotor three complete cavities with two
half cavities at each end. The soap temperature was 25C
input and 35C at exit with cooling applied to the stator
and rotor. The throughput was 400 g/minute from a soap
plodder with the rotor operated at 35 r.p.m.
Using headspace analysis with a gas chromatograph it
was found the conventional processed soap retained 60% of
original perfume and the soap mixed according to the
invention retained 75%.
