Note: Descriptions are shown in the official language in which they were submitted.
~ 323277
- 1 - C.3236
PROCESS FOR PREPARING
DETERGENT COMPOSITIONS
TECHNICAL FIELD
.
The present invention relates to a process for
preparing granular detergent compositions of high bulk
densitv having good washing performance and good powder
properties.
BACKGRO~ND AND PRIOR APT
Recently there has been considerable interest within
the detergents industry in the production of detergent
powders having relatively high bulk density, for example,
600 g/litre and above. Particular attention has been
paid to the densification of spray-dried powders hy~
post-treatment. For example, GB 1 517 713 (Unilever~
discloses a process in which a detergent powder produc~d
bv spray-drying or pan granulation is spheronised and
granulated in a ~Imarumerizer~ tTrade Mark) with some
increase in bulk density.
1 323277 2 C.3236
EP 229 671A (Kao) discloses a process in which a
spray-dried detergent powder containing surfactant and
builder is sub~ected successively to pulverising and
granulating treatments in a high-speed mixer/granulator,
the granulation being carried out in the presence of an
"agent for improving surface properties" and optionally a
hinder. In the Examples, the agent for improving
surface properties is zeolite 4A (10 parts), used
together with water (2 parts) as binder. After
granulation, a further 3 parts of zeolite 4A are admixed
with the product.
JP 84 041680B (Kao) describes a process in which a
spray-dried detergent base powder is pulverised, mixed
with powderv granules, having a crystallinity of 0-10~%
and a particle size of 0.1-300 microns, of sodium
aluminosilicate, calcium silicate, calcium carbonate,
magnesium silicate or sodium carbonate, and
simultaneously or subsequently mixed with a tackifying
substance, for example, a nonionic surfactant, alkyl
ether sulphate or higher alcohol.
EP 220 024A (Procter & Gamble) discloses a process
for the densification of a spray-dried powder containing
a high level (30-85 wt%) of anionic surfactant.
The powder is compacted and granulated, inorganic builder
(sodium tripolyphosphate, or crystalline sodium
aluminosilicate and sodium carbonate) being added before
compaction and/or after granulation.
The present inventors have now discovered that
detergent compositions of high bulk density and
excellent flow properties can be prepared by granulating
a spray-dried or dry-mixed aetergent base powder in a
.
;: : ':' : ~
~32~2~7 - 3 ~ C.3236
high-speed mixer/granulator and then admixing a small
amount of finely divided amorphous aluminosilicate after
granulation is complete. The amorphous material is
substantially more weight-effective than crystalline
zeolite for this purpose.
DEFINITION OF THE INVENTION
The present invention accordingly provides a process
for the preparation of a granular detergent composition
or component having a bulk density of at least 650
g/litre, which comprises the steps of:
(i) treating a particulate material comprising
one or more non-soap detergent-active compounds and
one or more inorganic builders in a hiqh-speed
mixer/granulator having both a stirring action and a
cutting action, in the presence of a liquid binder,
whereby granulation and densification to a bulk
density of at least 650 g/litre are effected,
(ii) admixing finely divided amorphous sodium
aluminosilicate to the granular material obtained in
step (i).
DETAILED DESCRIPTION OF THE INVENTION
The process
In the process of the invention, a particulate
starting material (detergent ba~e powder) prepared by any
suitable method is treated in a high-speed
,. ' ", ', ~ ~
1323277 - 4 ~ C.3~36
mixertgranulator to increase its bulk density and
simultaneously to improve its powder properties. The
process of the invention provides a route for the
production of very dense granular detergent compositions
having excellent cleaning performance and good powder
properties.
In the process of the invention, granulation is
effected by means of a high-speed mixer/granulator having
both a stirring action and a cutting action. Preferably
the stirrer and cutter may be operated independently of
one another and at separately variable speeds. Such a
mixer is capable of combining a high enerqy stirring
input with a cutting action, but can also be used to
provide other, gentler stirring regimes with or without
the cutter in operation. It is thus a highly versatile
and flexible piece of apparatus.
A preferred type of high-speed mixer/granulator for
use in the process of the invention is bowl-shaped and
preferably has a substantially vertical stirrer axis.
Especially p~ef~rred are mixers o~ the Fukae (Trade Mark)
FS-G series manufactured by Fukae Powtech Kogyo Co.,
Japan; this apparatus is essentially in the form of a
bowl-shaped vessel accessible via a top port, provided
near its base with a stirrer having a substantially
vertical axis, and a cutter positioned on a side wall.
The stirrer and cutter may be operated independently of
one another, and at separately variable speeds.
Other similar mixers found to be suitable for use in
the process of the invention are the Diosna (Trade Mark)
V series ex Dierks & Sohne, C.ermany; and the Pharma
Matrix (Trade Mark) ex T R Fielder Ltd., England. Other
similar mixers believed to be suitable for use in the
~: .
;
1 3 2 ~ 2 ~ ~ C.3236
process of the invention include the Fuji (Trade Mark)
VG-C series ex Fuji Sangyo Co., Japan; and the Roto
(Trade Mark) ex Zanchetta & Co srl, Italy.
- 5 Another mixer found to be suitable for use in the
process of the invention is the Lodige tTrade Mark) FM
series batch mixer ex Morton Machine ~o. Ltd., Scotland.
This differs from the mixers mentioned above in that its
stirrer has a horizontal axis.
As indicated above, the use of a high-speed
mixer/granulator is essential in the process of the
invention to effect granulation and densification. Jf
desired, the mixer may also be used for a pretreatment
step before granulation is carried out.
For example, it is within the scope of the
invention for the particulate starting material to be
prepared at least in part by mixing in the high-speed
mixer/granulator. ~hus, a dry-mixed ~tarting powder may
be prepared from its raw materials in the hiqh-speed
mixer/granulator; or one or more further ingredients may
be admixed with an otherwise premi,xed powder prepared
e,lsewhere (for example, by sprav-clrying). A suitable
~tirring/cutting regime and re~idence time may be chosen
in accordance with the materials to be mixed.
Another possible pretreatment that may he carried
out in the high-speed mixer/granulator is pulverisation;
whether or not this is necessary depends, among other
things, on the method o~ preparation of the starting
powder and its free moisture content. Powders prepared
by spray-drying, for example, are more likely to require
pulverisation than powders prepared by dry-mixing.
Again, the ~lexibility of the apparatus allows a suitable
:: ': . ~
~3~32~ ~ - 6 - C.3236
stirring/cutting regime to be chosen: generally
relatively high speeds for both stirrer and cutter. A
relatively short residence time (for example, 2-4 minutes
for a 35 kg batch) is generally sufficient.
An essential feature of the process of the invention
is the granulation step, during which densification to
the very high values of at least ~50 g/litre, preferably
a~ least 700 g/litre occurs, giving a dense, granular
product of very uniform particle size and generally
spherical particle shape.
Granulation i5 effectea by running the mixer at a
relatively high speed using both stirrer and cutter; a
relatively short residence time lfor example, 5-8 minutes
for a 35 kg batch) is generally sufficient. The final
bulk density can be controlled by choice of residence
time, and it has been found that the powder properties of
the resulting granulate are not optimum unless the bulk
densitv has been allowed to rise to at least 650 g/litre.
The presence of a li~uid binder is necessary for
successful granulation. The amount o~ binder added
preferahly does not exceed that needed to brin~ the free
moisture content of the composition above about 6 wt~,
since higher levels may lead to a deterioration in the
flow properties of the final granulate. If necessary,
binder, preferably water, may be added before or during
granulation, but some starting powders will inherently
contain sufficient moisture. If a liquid binder is to
be added, it may be sprayed in while the mixer is
xunnin~. In one preferred mode of operation, the mixer
is first operated at a relatively slow speed while binaer
is added, before increasinq the speed of the mixer to -
effect granulation.
-:: . : :
- ;': ;'' , ~ :
. :
,
~32327~ C.323~
If the starting powder has a sufficient free
moisture con~ent to render the addition of a binder
unnecessary, pulverisation (if required3 and granulation
need not be regarded as separate process steps but as one
single operation. Indeed, it is not, in that case,
necessary to decide in advance whether or not
pulverisation is required: the mixer may simply be
allowed to do what is necessary, since the mixer
conditions required are qenerally substantially the same
for pulverisation and for granulation.
In accordance with the invention, finely divided
amorphous sodium aluminosilicate is admixed with the
granular material after granulation is complete.
Advantageouslyr t.he amorphous sodium aluminosilicate is
added while the granulate is still in the high-speed
mixer/granulator, and the mixer is operated at a slow
speed for a further short period. No further
granulation occurs at this stage. It is also within
the scope of the invention to add the amorphous sodium
aluminosilicate to the granulate after removing the
latter to different apparatus.
The granulation stage is preferably carried out at a
controlled temperature somewhat above ambient, pre~erably
above 30C. The optimum temperature is apparently
formulation-dependent, but appears generally to lie
within the range of from 30 to 45C, preferably about
35C. This temperature may also be maintained during
the admixture of the finely divided amorphous sodium
aluminosilicate.
.
:-;
~3`~2~7 - 8 - C.3236
The amorphous sodium aluminosilicate
The amorphous sodium aluminosilicate used in the
process of the present invention is a finely divided
~ 5 particulate material. The preferred average particle
size is 0.1 to 20 microns, more preferably 1 to 10
microns. A suitable material is available commercially
from Crosfield Chemicals Ltd, Warrington, Cheshire, under
the trade mark Alusil.
The amorphous sodium aluminosilicate is
advantageously used in an amount of from 0.2 to 5.0 wt~,
based on the starting powder, more preferably from 0.5 to
3.0 wt%.
This material is effective even at very low level~
in improvin~ flow properties, and also has the effect of
increasing bulk density. It is therefore possible to
adjust bulk density by appropriate choice of the level of
amorphous aluminosilicate added after granulation,
The amorpholls material used in the process of the
invention should be distinguisbed from zeolite (hydrated
crystalline sodium aluminosilicate) which i6
substantially less weight-effective in the context of the
present invention. ~ubstantially higher levels than
those quoted above are needed before any comparable flow
or bulk density benefit is observed.
The starting powder
The process of the invention may be used to densify
and improve any detergent powder prepared by any tower or
non-tower method, for example, spray-drying or dry
,::
:: ,: , ::
. .~ ,, ~: :
~ 3~`~2 ~7 - 9 - C.3236
mixing. If desired, the particulate starting material
may be prepared at least partially by mixing in the
high-speed mixer/granulator itself. The particulate
starting material may consist at least partially of a
spray-dried powder.
The process of the invention has been found to give
especially satisfactory results with detergent base
powders containing low to moderate levels of surfactant
and relatively high levels of inorganic builder.
According to a first preferred embodiment of the
invention, the process is used ~or the preparation of
high-bulk-density powders containing substantial levels
of sodium aluminosillcate builder. These powders
preferably contain not more than 5 wt% of phosphate
builders, and are more preferably substantially free of
phosphate builders.
Thus a preferred starting powder might comprise:
(a) from S to 35 wt% of non-soap
detergent-active material, and
(b) from 28 to 45 wt% (anhydrous basis) of
crystalline or amorphous sodium aluminosilicate,
the weight ratio of (b) to (a) being at least 0.9:1, and
optionally other detergent components to 100 wt%.
The process of the invention is outstandingly
suitable for preparing the high-bulk-density powders,
containing moderate levels of surfactant and high levels
of zeolite, described and claimed in our copending
application of even date (Case C.3235). These powders
comprise:
,
l 3 2 3 2 I 1 C.3236
ta~ from 17 to 35 wt% of non-soap detergent-active
material consisting at least partially of anionic
~ detergent-active material, and
- 5 (b3 from 28 to 45 wt~ (anhydrous basis) of
crystalline or amorphous sodium aluminosilicate,
the weight ratio of (b) to (a) bein~ from 0.9:1 to 2.6:1,
and optionally other detergent components to 100 wt%.
The aluminosilicate builder present in the
starting powder may be crystalline or amorphous or a
mixture thereof, and has the general formula
0.8 1.5 Na2O.A 2 3 2
These materials contain some bound water and are
required to have a calcium ion exchange capacity of at
least about 50 mg CaO/g. The preferred aluminosilicates
contain 1.5-3.5 SiO2 units (in the formula above) and
have a particle size of not more than about 100 microns,
preferably not more than about 20 microns. Both
amorphous and crystalline aluminosilicates can be made
readily by reaction between sodium silicate and sodium
~5 aluminate, as amply described in the literature.
Crystalline aluminosilicates (zeolites) are
preferxed in the low- or zero-phosphate starting powders
treated by the process of the present invention.
Suitable materials are described, for example, in
GB 1 473 201 IHenkel~ and GB 1 429 143 tProcter &
Gamble). The preferred sodium aluminosilicates of this
type are the well-known commercially available zeolites A
and X, and mixtures thereof. Type 4A zeolite is
especially preferred.
- 11 - C.3236
:~3232 ~
The ratio of aluminosilicate builder (anhydrous
basis) to total non-soap surfactant in the starting
powder is preferably within the range of from 1.2:1 to
1 . ~ : 1 .
s
According to a second preferred embodiment of the
invention, the process is used for the preparation of
high-bulk-density powders containing substantial levels
of water-soluble inorganic salts, including sodium
tripolyphosphate and/or sodium carbonate, as described
and claimed in our copending application of even date
(Case C.3261).
Thus a preferred starting powder might comprise: ~ -
.5
(x) from 12 to 70 wt% of non-soap detergent-active
material, and
.
(y) at least 15 wt~ of water-soluble inorganic
salts, including sodium tripolyphosphate andlor
sodium carbonate,
the weight ratio of (y) to (x) being at least 0.4:1, and
optionally other detergent components to 100 wt%.
Preferably the weight ratio of (y) to (x) is within
the range of from 0.4:1 to 9:1, more preferahly from 1:1
to 9:1. A~ especially preferred starting powder
contains from 15 to 70 wt% of water-soluble inorganic
salts, more preferably from 15 to 50 wt%, especially from
20 to 40 wt%, of sodium tripolyphosphate.
In both the first and second preferred embodiments
of the invention, the non-soap surfactant present in the
starting powder preferably consists at least partially of
. ~, . . . . . .
- 12 - C.3236
~ 3232~1
anionic surfactant. Suitable anionic surfactants will
be well known to those skilled in the art, and include
linear alkvlbenzene sulphonates, particularly sodium
linear alkylbenzenesulphonates having an alkyl chain
~ 5 length of C8-C15; primary and secondary alkvl sulphates,
particularlv sodium C12-C15 primarv alcohol sulphates;
alkyl ether sulphates; alpha-olefin and internal olefin
sulphonates; alkane sulphonates; dialkyl
sulphosuccinates; fatty acid ester sulphonates; and
combinations thereof.
If desired, the starting powder may contain nonionic
surfactant. Nonionic surfactants too will be well known
to those skilled in the art, and include primary and
secondary alcohol ethoxylates, especiallv the C12-Cl5
primarv and secondary alcohols ethoxylated with an
average of from 3 to 20 moles of ethylene oxide per mole
of alcohol.
Suitably the surfactant component of the
starting powder may be constituted by from 0 to 70~,
preferably from 8 to 60~ by weight, of anionic
suxfactant, and from 0 t~ 20%, preferably from 0 to 10~,
by weight of nonionic surfactant.
~ther types of non-soap surfactant, for example,
cationic, zwitterionic, amphoteric or semipolar
surfactants, may also be present if desired. Many
suitable deteraent-active compounds are available and are
fully described in the literature, for example, in
"Surface-Active Agents and Detergents", Volumes I and II,
by Schwartæ, Perrv and Berch.
--- :~ ; :
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~32~2~7 C.3236
If desired, soap mav also be present, to provide
foam control and additional detergency and builder power;
soap is not included in the figures for the surfactant
content quoted previously.
The final granulate has a bulk density of at least
650 g/litre and preferably at least 700 g/litre. It is
also characterised by an especially low particle
porosity, not exceeding 0.25 and preferably not exceeding
0.20, which distinguishes it from even the densest
powders prepared hy spray-drying alone.
.....
The final granulate may be used as a complete
~etergent composition in its own right. Alternatively,
it may be admixed with other components or mixtures
prepared separately, and may form a major or minor part
of a final product. Generally any additional
ingredients such as enzymes, bleach and perfume that are
not suitable for undergoing the granulation process may
be admixed to the granulate to make a final product.
A detergent base powder may, for example, be
prepared by spray-drying an a~leous slurry of
heat-in~ensitive and compatible ingredients; if
desired, other ingredients may then be admixed; and the
resulting powder densified and granulated in accordance
with the present invention. Yet further ingredients may
if desired be admixed after granulation; the densified
granulate may typically constitute from 4Q to 100 wt% of
a final product.
Alternatively, a detergent base powder may be
prepared by dry mixing one or more raw materials and/or
one or more premixes of raw materials, in the high-speed
mixer/granulator itself or in other apparatus, and then
i3232~ ~ 14 - C.3236
densified and granulated in accordance with the present
invention. Again, further ingredients may if desired be
added after granulation.
Yet again, the granulate prepared in accordance with
the present invention may be an "adjunct" comprising a
relatively high level of detergent-active material on an
inorganic carrier; and this may be admixed in a minor
amount with other ingredients to form a final product.
The invention is further illustrated by the
following non-limiting Examples, in which parts and
percentages are by weight unless otherwise stated.
, ,~ ~ :.. ., . . . .. :
: ~. . : : :::
: .~ :
~323277 - 15 - C.3236
EXAMPLES
Example 1
.....
A detergent composition having a bulk density of 350
g/litre was prepared to the following composition by
spray-drying an aqueous slurry:
Linear alkylbenzene sulphonate 20.0
Nonionic surfactant 2.0
Soap 1.0
Zeolite (anhydr.) 35.0
Water with zeolite 10.0
Sodium silicate 4~0
Sodium succinate 2.0
Acrylate/maleate copolymer 2.0
Sodium sulphate 10.45
Sodium carbonate 10.0
Minor ingredients 1.55
Free moisture 2.0
1 00 . O
.:
It will be noted that the ratio of zeolite
tanhydrous) to non-soap surfactant in this composition
was 1.59.
-. i . ' ' :.' . - ' : '
13232~7
- 16 - C.3~36
25 kg of this spray-dried powder were introduced
into a Fukae (Trade Mark) FS-G series high-speed
mixer/granulator, and pulverised at high speed (stirrer
180 rpm, cutter 3013 rpm) for 4 minutes at 32C. Water
(500 g, 2.0~) was then spraved in over a period of 0.5
min while the mixer was allowed to run at a slower speed
(stirrer 100 rpm, cutter 3000 rpm) at a temperature of
35C. The mixer was then allowed to run at an stirrer
speed of 140 rpm, a cuttex speed of 2700 rpm and a
temperature of 36-37C to effect granulation.
After granulation was complete, Alusil (Trade Mark)
fine amorphous sodium aluminosilicate (250 g, 1%) was
introduced into the Fukae mixer, which was then operated
at a slow speed ~stirrer 90 rpm, cutter 300 rpm)
for 1 minute. The resulting granular product was
free-flowing and showed no tend~ncv to cake. Its
properties, and those of a sample removed before the
addition of the Alusil, are shown in Table 1 below.
It will be noted that the final mean particle size
after Alusil addition was slightly sma]ler than before
the add;tion of the Alusil, showing that a minor amount
of deqranulation had occurred during this treatment.
Surprisinglv, however, the percentage of fine particles
had decreased. The substantial increase in bulk density
effected by the addition of Alusil will be nvted.
.
.;
:
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: . . :: - : . : j .
: ` , :: ~
~323277 - 17 ~ C.3236
Table 1
Before After
Alusil Alusil
~ 5 addition addition
Bulk density (g/l) 794 892
Mean particle size tmicrons) 785 704
Dynamic flow rate (ml/s) 25 120
Fines (wt% of particles
<180 microns) 13 8
Particle porosity <0.20 <0.20
Examples 2 & 3, Comparative Examples A ~ B
2Q
In these Examples, the effect of adding Alusil after
granulation was compared with the effect o adding
~rystalline zeolite 4A ater ~ranulation. Samples of
the spray-dried powder used in Example 1 were treated in
the Fukae mixer as described in that Example, Alusil or
zeolite as shown in Table 2 below being added after
granulation was complete.
. . ' ' :~ ,, ,: - :
.
~ ..
1 3 ~ 3 2 7 1 - 18 - C.3236
Table 2
Example 2 3 A B
Flow aid lwt ~
Alusil 1.0 1.7
Zeolite - - 1.0 3.0
10Bulk density (g/l)856 854 740 784
Dynamic flow rate
(ml/s) 92.3 ~2.3 33.5 42.5
Particle size
(microns) 507 546 530 529
Fines content (wt~
20<180 microns) 11 8 2
The large differences in both bulk density and
dynamic flow rate will be noted.
Example 4
This Example descrihes the preparation of a complete
detergent product using the process of the invention.
A detergent composition was prepared to the
followin~ composition by spray-drying an aqueous slurry
to a free moisture content of substantially zero:
~ 3 2 3 2 ~ 7 19 ~ C.3236
~arts
Linear alkvlbenzene sulphonate 24~0
Nonionic surfactant 2.0
Soap 1.0
Zeolite (anhydr.) 38.0
Water with zeolite 10.84
Sodium silicate 4.0
Acrylate/maleate copolymer 2.0
Minor ingredients 2.0
Sodium carbonate 10.0
94.6
It will be noted that the ratio of zeolite
(anhydrous) to non-soap surfactant in this composition
w~s 1.46.
35 kg of this spray-dried powder were introduced
into a Fukae (Trade Mark) FS-C. series high-speed
mixer/granulator, and pulverised at high speed for 2-4
minutes. The mixer was then stopped, water (2.0 parts)
was sprayed in, and the mixer was then restarted at a
slower speed and allowed to run for 5-8 minutes while the
temperature was maintained at about 35C; during this
period granulation occurred.
A sample of the granular product was removed from
3Q the Fukae mixer. It was free-flowing and showed no
tendencv to cake. Its dynamic flow rate was 65 ml/s.
.
- .' :;
; : . : - . . .
~32327~ - 20 ~ C.3236
1.0 part of Alusil (Trade Mark) fine amorphous
sodium aluminosilicate was introduced into the Fukae
mixer, which was then operated at a slow speed for l
minute. The resulting granular product was free-flowing
- 5 and showed no tendency to cake. Its bulk density was
740 g/litre and its particle porosity was less than 0.20.
Its mean particle siæe was 405 microns, and its dynamic
flow rate was 105 ml/s.
The following ingredients were then mixed with the
granular material to give 100 parts of final detergent
powder:
Coloured speckles 1.5 parts
Enzyme (alcalase) 0.61 parts
Perfume 0.25 parts
Example 5, Comparative Example C
35 kg of the spray-dried powcler used in Example 4
were intro~uced into a I,adige (Trade Mark) FM series
high-speed mixer/granulator, and pulverised for 4
minutes. Water (1.1 kg, 3.5%) was then sprayed in while
the mixer continued to run at the same speed, then the
mixer was allowed to run for a further 3 minutes while
the temperature was maintained at about 35C. During
this period granulation occurred. A sample
(Comparative Example C) was removed from the mixer and
its properties are shown in Table 3 below.
~323277 - 21 - C.3236
Alusil (Trade Mark) finely divided amorphous sodium
aluminosilicate (1.2 kg) was then introduced into the
mixer which was allowed to run for a further 0.5 minutes.
The properties of the resulting powder (Example 5) are
shown in Table 3 below, from which the benefits of adding
a flow aid after granulation is complete are apparent.
The presence of the Alusil did result in an increase in
the content of fine particles <180 microns, but not to an
unacceptable level.
Comparative Example D
28.8 kg of the spray-dried powder used in Example 4
were introduced into a Lodige (Trade Mark) FM series
high-speed mixer/~ranulator, and pulverised for 4
minutes. Alusil ~Trade Mark) finely divided amorphous
sodium aluminosilicate (1.2 kg) was then introduced into
the mixer. Water (1.1 kg, 3.5~) was sprayed in while the
mixer continued to run, then the mixer was allowed to run
for a further 3 minutes while the temperature was
maintained at about 35~C. During this period granulation
occurred. The properties of the resulting powder are
showll in ~able 3 below, from which the detrimental effect
of adding Alusil before granulation are apparent. It
will be noted that the increase in fines content is
significantly greater when the Alusil is adaea before
granulation.
`
, I
1 323277 C.3236
Table 3
Example C 5 D
~ulk density (g/l) 680 754 704
Dynamic flow rate (ml/s) 100 109 59
Particle size (microns) 573 524 424
Fines content (wt% of
particles <180 microns) 0 15 ~5
Particle porosity <0.20 <0.20 not
measured
Comparative Example E
The procedure of Comparative Example D was repeated,
but the Alusil was added before the pulverisation step
instead of after it. Pulverisation and granulation were
carried out as in previous Examples, but the resulting
product ha~ a dynamic flow rate of zero.
~5
Example 6, Comparative Example F
20 kg of the spray-dried powder used in Example 4
were introduced into a Fukae (Trade Mark~ FS-30
high-speed mixer/granulator, and pulverised for 4
minutes~ Water tO.8 kg) was then added and the mixture
granulated over a period of 4 minutes, while the
temperature was maintained at about 35C. A sample
(Ccmparative Example F) was removed from the mixer and
its po~wder properties determined: these are shown in
Table ~ below~
.. , , ,., .. :. , ,: .: .............. : .: ~
,. :. .:. .: :. - . : .
., . ~ ;,. ~ . , .
~323277 - 23 - C.3236
Alusil (Trade Mark) finely divided amorphous sodium
aluminosilicate (0.2 kg) wasi then admixed. The ph~sical
properties of the resulting powder (Example 6) are shown
in ~ahle~ ~ below; the results were similar to those
~ tatn~
~e~ in Examples ~ and C using the Ladige mixer.
Comparative Example G
10 20 kg of the spray-dried powder used in Example 4
were introduced into the Fukae high-speed
mixer/granulator, and pulverised for 4 minutes. Alusil
(Trade Mark~ finely divided amorphous sodium
aluminosilicate (0.2 kg) was then introduced into the
mixer. Water (0.8 kg) was then added and the mixture
granulated over a period of 4 minutes, while the
temperature was maintained at about 35~C. Ph~sical
properties of the resulting powder are shown in Table ~
below: the results were similar to those ohtained using
the I,odige mixer (Comparative Example D~.
, .. ,,, , . .~.
: :.. :. ~ ~ :: ~.
, ., .:
~2 32 7~ 24 - C.3236
Table ~
~`
F
Example ~ ~ G
Bulk density (g/l) 688 740670
Dynamic flow rate (ml/s) 109 120 60
Particle size (microns) 550 480 380
Fines content (wt% of
particles < 180 microns) 0 10 22
Particle porosity 0.1 0.1not
measured
~0
~ ,. .. , . ~ , .. ....
~32~77 - 25 - C.3236
Example 7, Comparative Example H
These Examples involved a process in which a powder
prepared by dry-mixing was densified and granulated in
~ 5 a high-speed mixer/granulator. The following
formulation was prepared by mixing in a concrete mixer:
~arts
10 Linear alkylbenzene sulphonate 24.0
Nonionic surfactant 2.0
Soap 1.0
Zeolite (anhydr.) 38.0
Water bound with zeolite 10.84
15 Sodium carbonate (light soda ash) 10.0
Sodium silicate 4,0
Acrylate/maleate copolymer 2.0
Minor ingredients 2.0
2n 92.24
The ratio of aluminosilicate to non-soap surfactant
in this mixt~re was 1.46.
20 kg of this formulation were placed in a Diosna
(Trade Mark) V100 mixer aand mixed for 1 minute at a
stirrer speed of 196 rpm and a cutter speed of 3000 rpm.
Water (0.2 kg) was added over a period of 2 minutes while
the mixer was operated at a stirrer speed of 9R rpm and a
cutter speed of 1500 rpm, then the mixture was granulated
for 4 minutes at a stirrer speed of 196 rpm and a cutter
speed of 3000 rpm. A sample (Comparative Example H) was
removed and its powder properties measured (see below).
Finally Alusil ~0.2 kg) was mixed in while the mixer was
operated at a stirrer speed of 98 rpm with the cutter
switched off; and the powd~r properties of the final
granulate (Example 7) were also measured.
-;
: . ;.~ ,
. ,-, ~ -. . .
. ..
~ 32327 7 26 - C.3236
The powder properties of the granulate before and
after the addition of Alusil were as follows:
H 7
Bulk density (g/l) 750 810
Dynamic flow rate (ml/s)80 96
Compressibility ( ~v/v)17.0 15.3
Particle size (microns) - 607
Particle porosity <0.20 <0O20
Example 8, Comparative Example J
A detergent powder built with sodium
tripolyphosphate was prepared by spray-drying an aqueous
sluxry to the following formulation:
wt ~ :
Linear alkyl~enzene sulphonate 9.7
Nonionic surfactant 2.8
Soap 4.9
Sodium tripolyphosphate42.5
Sodium sulphate 14.8
Sodium silicate 10.0
Minor ingredients 2.8
Water 12.5 .
100.0
` ` ` ` ~, ' . , ., ` `,` '., : ' !
13232~ 27 - C.3236
The ratio of water-soluble crystalline inorganic
salts (sodium tripolyphosphate ancl sodium sulphate) to
non-soap surfactan~ was 4.6:1.
Two separate 20 kg batches of this powder were
densified in the Fukae mixer, as follows. The powder
was initially subjected to a 2-3 minute warming-up
period, with the stirrer running at 50 rpm and with the
cutter switched off, until the temperature had reached
about 30-35C. Pulverisation for 0.5 min~tes at a
stirrer speed of 180 rpm and a cutter speed of 1000 rpm
followed; water (0.5 wt%) was added over 0.5 minutes
while the mixer was operated at a stirrer speed of lO0
rpm and a cutter speed of 3000 rpm; then granulation was
carried out for 6 minutes at a stirrer speed of 140 rpm
and a cutter speed of 3000 rpm.
To the first sample (Example 8), Alusil (1.5 wt~ )
was added over a period of 1 minute while the mixer was
operated at a stirrer speed of 90 rpm and a cutter speed
of 300 rpm.
To the second sample (Comparative Example J),
zeolite (5 wt%) was added over the same period of time
and under the same mixer conditions.
Powder properties were as follows:
8 J
Yield <1700 microns (wt~) 93 97
Average particle size (microns) 555 480
Bulk density (g/litre) 840 780
Dynamic flow rate (ml/s) 92 61
35 Compressi~ility (~v/v) 7 12
Particle porosity ~0.20 ~0.20
- ., . ; ~ ' '-' ~ ' : '
,, ~ :. :
1 32 32~rl - 28 ~ C~3236
Example 9, Comparative Example K
This Example illustrates the sequential addition of
zeolite and Alusil to a densified powder.
A detergent base powder was prepared to the
following composition by spray-drying an aqueous slurry
to a free moisture content of substantially zero:
parts
Linear alkylbenzene sulphonate 24.0
Nonionic surfactant 2.0
Soap 1.0
Zeolite 4A (anhydrous) ) ( 27.27
Water with zeolite ) ( 7.73
Sodium silicate 4.0
Acrylate/maleate copolymer 1.0
Minor ingredients 2.85
2n Sodium carbonate 16.51
The weight ratio of anhydrous zeolite to non-soap
detergent in this base powder was 1.05~
90 parts of this base powder were granulated and
densified in the Fukae mixer as described in previous :
Examples, then a further 10 parts (hydrated basis) of
zeolite 4A were admixed. A sample (Comparative Example
K) was removed, and then Alusil (0.4 parts~ was added to -
give a final granulate (Example 9).
~3232~7 - 29 - C.3236
The powder properties are shown below, and
demonstrate that the final addition of Alusil, in the
small quantity of 0.5 parts to 100, effected significant
increases in bulk density and flow rate, and decreases in
cohesiveness and caking, even though 10 parts of zeolite
had already been postdosed.
K 9
Pulk density, g/l 732 760
Dvnamic flow rate, ml/s 85 98
Powder cohesiveness ~) 10 9
Powder caking after storage
in cartons for 6 months (~) 1 n 5
Particle porosity <0.20<0.20
,
. :~
;~:
