Note: Descriptions are shown in the official language in which they were submitted.
~2~7~
- 1 - C. 3261
DETERGENT COMPOSITIONS
AND PROCESS FOR PREPARING T~IElq
5 TECHNICAL FIELD
The present invention relates t:o granular detergent
compositions of high bulk density having good washing
performance and good powder propert.ies, and a process for
preparing them.
BACKGROUND AND PRIOR ART
.
Recently thexe has b~en considerable interest within
~he detergents indus~ry in the production of de~ergent
powders having relatively high bulk density, for exarnple,
60~ g/litre and above. Particular attention has been
paid to the densification of spray-dried powders by
20 post-txeatment. EP 219 328A (~nilever) published
April 22, 1987, discloses a granular low-phosphate
detergent composition prepared by spray-drying a slurry to
give a base powder contaîning a low to moderate level of
sodium tripholyphosphate builder and low levels of
inorganic salts, and th~n postdosing _ _
~22~
-- 2
solid material including sodium sulphate of high bulk
density and of smaller particle size than the base powder~
thus filling the voids between base powder particles and
producing a product of high bulk density.
JP 61 069897A (Kao) publishad April lO, 1986,
discloses a process in which a spray-dried detergent powder
containing a high level of anionic sur~actant and a low
level o~ builder (zeolite) is subjected successively to
pulverising and granulating treatments in a high-speed
mixer/granula~or, the granulation being carried out in the
presence of an "agent for improving surface properties~' and
optionally a binder. It would appear that in the high-
speed mixer/granulator, the spray-dried powder is initially
broken down to a fine state of division; the surface-
improving agent and optional binder are then added and the
pulverised material granulated to form a final product of
high bulk density. -The surface-improving agent, which is a
finely divided particulate solid such as fine sodium
aluminosilicate, is apparently requixed in order to prevent
the composition from forming into large balls or cakes.
EP 229 671A (Kao) published July 22, 1987, discloses
postdosing a crystalline alkaline inorganic salt, for
example, sodium carbonate, to a spray-dried base powder
prepared as in the above-mentioned JP 61 069897A (Kao) and
containing a restricted level of water-soluble crystalline
inorganic salts, to produce a high bulk density product.
GB 1 517 713 (Unilever) published July 12, 1978,
discloses a process in which spray-dried or granulated
detergent powders containing sodium tripolyphosphate and
sodium sulphate are densified and sphexonised in a
"marumerizer~' (Trade Mark).
~3227~
- 3 - C.3261
GB 1 453 697 (Unilever) discloses the use of the
same apparatus to granulate together detergent powder
components in the presence of a liquid binder to form a
granular detergent composition. The "marumerizer~
comprises a substantially horizontal roughened rotatable
table positioned within and at the base of a
substantially vertical smooth-walled cylinder. The
disadvantage associated with this apparatus is tha~ it
produces powders or granules having a rather wide
particle size distribution, and in particular containing
a relatively high proportion of oversize particles.
Such products exhibit poor dissolution and dispersion
characteristics, particularly in low-temperature short
duration machine washes as used in Japanese and other
far-eastern washing machines. This can be apparent to
the consumer as deposits on washed fabrics, and in
machine washing leads to a high level of wastage.
EP 220 024A ~Procter & Gamble) published April 29,
1987, disclosed a process in which a spray-dried detergent
powder containing a high level (30-135 wt~) of anionic
surfactant is mixed with an inorganic builder ~sodium
tripolyphosphatel or sodium aluminosilicate and sodium
carbonate) and compacted under high pressure using a roll
compactor (~chilsonatox~; the compacted material, after
removal of oversize material and fines, is then granulated
using convantional apparatus, for example, a fluidised bed,
tumble mixer, or rotating drum or pan.
EP 158 419A (Hashimura) published October 16, 1985,
disclosPs the preparation of a detergent powder by mixing a
majox proportion of soda ash (preferably 70 to 85 wt~ of
the mixture) and a minor proportion of surfactan~ (wholly
or predominantly nonionic) in a high-speed
mixer/granulator.
~L 3 2 2 r~
~ 4 - C.3261
It has now been found that spray-dried powders
containing moderate or high levels of water-soluble
crystalline inorganic salts, including sodium
tripolyphosphate and/or sodium carbonate, can be
granulated and densified in a high-speed
mixer/granulator, if necessary after pulverisation,
without the need for an "agent for improving surface
properties" or similar pulverulent material, even when
high levels of anionic surfactant are present.
DEFINITION OF THE INVENTION
The present invention provides a process for the
preparation of a granular detergen~ composition or
component having a bulk density of at least 650 g/litre,
which comprises the step of treating a particulate
starting material comprising:
(a) from 12 to 70 wt% of non-soap
detergent-active material, and
(b) at least lS wt~ of water-soluble
crystalline inorganic salts, including sodium
tripolyphosphate and/or sodium carbonate,
the weight ratio of (b) to (a) being at least 0.4:1,
and optionally other detergent components to 100 wt%,
in a high-speed mixer/granulator having both a stirring
action and a cutting action, in the absence of a finely
divided particu~ate agent for improving surface
properties, whereby granulation and densification to a
bulk density of at least 650 g/litre are effected.
~ 3 ~
- 5 - C.3261
DETAILED DESCRIPTION OF T~E INVENTION
The invention is concerned with a process for the
preparation of a detergent powder combining high bulk
density, good powder properties and excellent washing and
c]eaning performance.
The present inventors have found that a detergent
base powder prepared by any suitable method and
containing substantial levels of water-soluble
crystalline inorganic salts may be processed in a
high-speed mixer/granulator, without the need for the use
of an ~ayent for improving surface properties" during the
granulation step as prescribed by JP 61 069897A (Kao), to
give a dense granulate having good flow properties, even
if relatively high levels of anionic surfactant are
present. The product is characterised by an especially
narrow particle size distribution, and in particular by a
very small proportion of oversize material, giving good
and rapid cold water dispersability and low insoluhle~.
The starting ~owder
A preferred starting powder has a ratio of total
water~soluble crystalline inorganic salts (b) to total
non-soap surfactant la~ within the range of from 0.4:1 to
9:1, more preferably from 0.4:1 to 5:1. An especially
preferred range for the xatio of ~b) to (a) is from 1~1
3 0 t:o 5 1 r
Preferably the starting powder contains a total of
from 15 to 70 wt~ of water-soluble crystalline inorganic
salts. A5 well as sodium tripolyphosphate and sodium
carbonate, examples of such salts include sodium
1 322 ~
- 6 - C.3261
sulphate, sodium ortho- and pyrophosphates, and
crystalline sodium silicates, that is to say, sodium
silicates having a ratio (SiO2 to Na20) < 1, such as
sodium orthosilicate and sodium metasilicate. The
alkaline and neutral silicates of higher ratio commonly
used in detergent compositions are not to be regarded as
crystalline.
According to a preferred embodiment of the
invention, the starting powder contains from 15 to 50
wt%, more preferably from 20 to 40 wt4, of sodium
tripolyphosphate.
The non-soap surfactant present in the starting
powder preferably consists at least partially of anionic
surfactant. Suitable anionic surfactants will be well
known to those skilled in the art, and include linear
alkylbenzene sulphonates, particularly sodium linear
alkylbenzenesulphonates having an alkyl chain length of
C8-C15; primary and secondary alkyl sulphates,
particularly sodium C12-C15 primary 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, especially the C12-C15
primary and secondary alcohols ethoxylated with an
average of from 3 to 20 moles of ethylene oxide per mole
of alcohol~
2 ~
- 7 - C.3261
Suitably the surfactant component of the
starting powder may be constituted by from 0 to 70%,
preferably from 8 to 60 wt%, of anionic surfactant, and
from 0 to 20%, preferably from 0 to 10%, by weight of
nonionic surfactant.
Other types of non-soap surfactant, for example,
cationic, zwitterionic, amphoteric or semipolar
surfactants, may also be present if desired. Many
suitable detergent-active compounds are available and are
fully described in the literature, for example, in
r'Surface-Active Agents and Detergents", Volumes I and II,
by Schwartz, Perry and Berch.
If desired, soap may also be present, to provide
foam control and additional detergency and builder power;
soap is not included in the 12 to 70~ figure for the
surfactant content ~uoted previously.
The starting powder may be prepared by any suitable
tower or non-tower method, for example, spray-drying or
dry mixing. The invention is especially useful for the
densification of a spray-dried powder.
If desired, at least part of the water-soluble
crystalline inorganic salt to be included in ~he final
product may be admixed to the remainder of the starting
powder in the high-speed mixer/granulator itself. In
this embodiment of the invention, the percentages and
ratios ~pecified above should be based on the total
material introduced into the high-speed mixer/granulator,
including the added salt.
2~
- 8 - C.3261
Thus it is within the scope of the present invention
to introduce into the high-spe~d mixer/granulator a
starting powder, prepared for example by spray-dryin~,
~ontaining less than the amount of water-soluble
crystalline inorganic salt specified above, and then to
admix with that powder, in the high-spPed
mixer/granulator, sufficient water-soluble crystalline
inorganic salt to bring the salt percentage (b) and the
ratio (b) to (a) up to the specified level.
Similarly, it is within the scope of the invention
to add surfactant, or indeed any other component, in the
high-speed mixer/granulator provided that the final
composition is as specified above, and provided that the
component so added is not a finely divided ~a~ent for
improving surface properties" as described in
JP 61 069897A (Kao) published April 10, 1986, disclosed
previously. Thus, in the process of the invention, any
component other than a finely divided particulate solid
having a particle si~e of less than 100 microns may be
added to the hiqh-speed mixer/granu:Lator prior to
granulation.
One procedure according to the invention includes the
step of admixing at least one inorganic or organic salt
having a particle size of at least 100 microns with the
remainder of ~he starting pow~er in the high-speed
mixer/granulator. If the salt is water-soluble, inorganic
and crystalline, it should be included within the
percentages and ratios specified above which relate to the
total amount of such salts in the material subjected to
granulation in the high-speed mixer/granulator.
~L322~
- 9 ~ C.3261
Salts that may conveniently be incorporated by this
method include borax, sodium bicarbonate, sodium
silicate, sodium tripolyphosphate, sodium carbonate,
sodium perborate, sodium percarbonate, sodium citrate,
sodium nitrilotriacetate, sodium succinate, sodium
sulphate and combinations of these. These salts can
give various benefits: for example, borax and sodium
bicarbonate a.re buffers ~iving mild products of low
in-wash pH.
The process
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. PrefPrably
the stirrer and the cutter may be operated independently
of one another, and at separately variable speeds~ Such
a mixer is capable of combining a high energy stirring
input with a cutting action, but can also be used to
provide other, gentler stirring regimes with or without
the cutter in operatio.n. 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 preferred are mixers of the Fukae (Trade Mark) v'
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 cuttex positioned on a si~e wall.
The stirrer and cutter may be operated independently of
one another, and at separately variable speeds.
: .
~ 3~27i'~
- 10 - C.3261
Other similar mixers found to be suitable for use in
the pxocess of the invention are the Diosna (Trade Mark)
V series ex Dierks & Sohne, Germany; and the Pharma
Matrix ~Trade Mark) ex T K Fielder Ltd., England. Other
similar mi~ers believed to be suitable for use in the
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.
Another mixer found to be suitable for use in the
process of the invention is the Ladige ~Trade Mark) FM
series batch mixer ex Morton Machine Co. 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. If
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, as previously indicated, for one or more
further ingredients to be admixed with an otherwise
premixed powder prepared elsewhere ~for example, by
spray-drying~. A sui~able stirring/cutting regime and
residence time may be chosen in accordance with the
materials to be mixed.
Another possible pretreatment that may be carried
out in the high speed mixer~granulator is pulverisation;
whether or not this is necessary depends, among other
things, on the method of preparation of the starting
powder and its free moisture content. Powders prepared
by spray-drying, for example, are more likely to require
13 2 2 rl ~ ~
11 - C.32~1
pulverisation than powders prepared by dry~mixing.
Again, the flexibility of the apparatus allows a suitable
stirring/cutting regime to be chosen: generally
relatively high speeds for both stirrer and cutter. A
relatively short re~idence time (for example, 2-4 minutes
for a 35 kg batch3 is generally sufficient.
The essential feature of the process of the
invention i5 the granulation step, during which
densification to the very high values of at least 650
g/litre, preferably at least 700 g/litre occurs, giving a
dense, granular product of very uniform particle size and
generally spherical particle shape.
Granulation is effected by running the mixer at a
relatively high speed using both stirrer and cutter; a
relatively short residence time (for example, 5-8 minutes
for a 35 kg batch) i5 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
density has been allowed to rise to at least 650 g/litre.
The presence of a liquid binder is necessary for
successful granulation. The amount of binder added
preferably does not exceed that needed to bring the free
moisture content of the composition above abou~ 6 wt%,
since higher levels may lead to a deterioration in th~
flow properti~s of the final granulate. If necessary,
binder, preferably water, may be added beore or during
granulation, but ome starting powders will inh~rently
Gontain sufficient moisture. If a liquid binder is to
be added, it may be sprayed in while the mixer is
running. In one preferred mode of operation, the mixer
r~
- 12 - C.3261
is fi~st operated at a relatively slow speed while binder
is added, before increasing the speed of the mixer to
effect granulation.
If the starting powder has a sufficient free
moisture content to render the addition of a binder
unnecessary, pulverisation (i~ required) 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 generally substantially the same
for pulverisation and for granulation.
According to a preferred embodiment of the
invention, granulation is carried out at a controlled
temperature somewhat above ambient, preferably above
30C. The optim~m temperature is apparently
formulation-~ependent, but appears generally to lie
within the range of from 30 to 45C, preferably about
35C.
It is an essential feature of the present invention
that during granulation no "agent for improving surface
properties" as defined in the above-mentioned JP 51 06~897
(Kao) published April 10, 1986, be present. When
processing a formulation having a relatively high ra~io of
aluminosilicate builder to surfactant, in accordance with
the present invention, the use of a finely divi~ed
particulate material such as fine sodium aluminosilicate
during the granulation step is not only unnecessary but can
with some formulations make granulation more difficult, or
even impossible.
~ ~2 ' ~
- 13 - C.3261
The optional flow aid
In accordance with a preferred embodiment of the
invention, a finely divided particulate flow aid may be
admixed with the granular material after granulation is
complete. Advantageously, flow aid 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 flow aid to the granulate after removing the
latter to different apparatus.
This embodiment of the invention should be
distinguished from the prior art process of JP 61 069897A
(Kao), mentioned above, in which an "agent for improving
surface properties", which can be fine sodium
aluminosilicate, is present during the granulation stage
itself. It is within the scope of the present invention
to add a particulate flow aid aftex granulation is
complete, but, as explained above, it is essential to the
invention that no finely divided particulate "agent for
improving surface properties" be prlesent during
granulation. The addition of ~ flow aid after
~5 granulation is complete can have an additional bPneficial
ef*ect on the properties of the granulate, regardless of
the formulation, whereas the presence of this type of
mat~rial during the granulation step in the process of
the invention makes processing more difficult.
The preferred granulation temperature of from 30 to
45C, preferably about 3S~C, may also be maintained
during the subsequent admixture of a flow aid.
~3~27~
- 14 - C.3261
The flow aid is a finely divided particulate
material. The preferred average particle size is 0.1
to 20 microns, more preferably 1 to 10 microns.
According to one preferred embodiment of the
invention, the flow aid is finely divided amorphous
sodium aluminosilicate, as described and claimed in our
copending application of even date (Case C.32363. A
suitable material is available commercially from
Crosfield Chemicals Ltd, Warrington, Cheshire, England,
under the trade mark Alusil. This material is !~
effective in improving flow properties even at very low
levels, 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
sodium aluminosilicate added after granulation.
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%.
Another preferred flow aid is finely divided
crystalline s~dium aluminosilicate. The crystalline
aluminosilicates discussed previously in the context of
builders are also suitable for use as flow aids. They
are, however, less weight-effective than the amorphous
material and are suitably used in an amount of from 3.0
to 12.0 wt%, more preferably from 4.0 to lO.0 wt~.
If desired, both crystalline and amorphous sodium
aluminosilicates may be used, together or sequentially,
as flow aids.
~322~ ~
- 15 - C.3261
Other flow aids suitable for use in the process of
the invention include precipitated silica, for example,
Neosyl (Trade Mark), and precipitated calcium silicate,
for example, Microcal (Trade Mark), both commercially
available fro~ Crosfield Chemicals Ltd, Warrington,
Cheshire, England.
The final ~ranulate
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, preferably not exceeding 0.25 and more
preferably not exceeding 0.20, which distinguishes it
from even the densest powders prepared by spray-drying
alone.
The final granulate may be used as a complete
detergent 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 add.itional
ingredients such as enzymes, bleach and perfume that are
not suitable for undergoing the granulation process and
the steps that precede it may be a~mixed to the granulate
to make a final product.
In one preferred embodiment of the invention, for
example, a detergent base powder is prepared by
spxay-drying an aqueous slurry of heat-insensitive and
compatible ingredients; if desired, other ingredients
may then be admixed as dis~ussed above; and the
resulting powder is densified and granulated in
accordance with the process of the invention. Yet
further ingredients may i desired be admixed after
~32~7~l~
- 16 - C.3261
granulation; the densified granulate may typically
constitute from 40 to 100 wt% of a final product.
In another embodiment of the invention, the
densified granulate prepared in accordance with the
present invention is an "adjunct'l 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.
~ 3 2 ~
- 17 - C.3261
EXAMPLES
In the Examples which follow, the following
abbreviations are used.
LAS: sodium linear alkylbenzene sulphonate
NI: nonionic surfactant ~ethoxylated alcohol)
NSD: total non-soap detergent
STP: sodium tripolyphosphate
Carbonate: sodium carbonate
Sulphate: sodium sulphate
Silicat.e: sodium alkaline silicate
g: good
Alu: Alusil (Trade Mark) N, finely divided
amorphous sodium aluminosilicate
Zeo: Zeolite 4A (Wessalith (Trade Mark? ex
Degussa)
13 2 2 ~
- 18 - C.3261
E~am~les 1 ~ 2
Powders containing sodium tripolyphosphate and
sodium sulphate were prepared by spray-drying aqueous
slurries to the formulations (weight %) shown in Table lo
Table 1
Example 1 2
LAS 12.2 9.7
NI 8.1 2.8
NSD (a) 20.3 12.5
STP 42.7 42.5
Sulphate 10.2 14.8
Salts (b) 52.9 57.3
Soap _ ~ g
Silicate 10.2 10.0
Minors 2.4 2.8
Water 14.2 12.5
(b):(a) 2.6 4.6 - -
20 kg batches of each powder were densified in a
Fukae (~rade Mark) high-speea mixer/granulator, process
conditions and resulting powder properties being shown in
Table 2. In Example 1, the powder was initially
subjected to a 2-3 minute warming up period, at a low
stirrer speed ~50 rpmj and without the cutter running,
until the temperature had reached about 30-35C. This
was followed by pulverisation (optional), then binder
addition talso~optional~, then granulation, followed
finally by addition of flow aid.
~3227~
- 19 - C.3261
Table 2
1 2(a) 2Ib)
Pulverisation:
Time (min) 4 0.5 0-5
Stirrer speed lrpm) 180 180 180
Cutter speed (rpm~ 3000 1000 1000
Binder lwater)~
Amount (wt %) 4 0.5 O.S
Addition time (min) 1 0.5 0.5
Stirrer speed (rpm) 100 100 100
Cutter speed ~rpm) 3000 3000 3000
Granulation:
Time (min) 15 7 6
Stirrer speed (rpm) 140 140 140
Cutter speed (rpm) 2700 3000 3000
Flow aid:
Zeo or Alu Alu Alu Zeo
Amount (wt ~) 2 1.5 5
Addition time (min)
Stirrer speed (rpm~ 90 90 90
Cutter speed (rpm) 300 300 300
______________,__ _________~_____ _._.____
Yield`<1700 ~m (wt %) 95 93 97
Average particle size ~m) 689 ~55 480
Bulk density (g/litre) 854 840 780
Dynamic flow rate (ml/s~ 109 92 61
Compressibility ~v/v) 7.6 7 12
Particle porosity~0,20 <0.20 <0.20
Comparison of Examples 2(a) and 2lb) shows the greater
weight-effec~iveness of Alusil as flow aid.
132~7~
- 20 - C.32~1
Examples 3 to 5
Powders containing sodium tripolyphosphate as the
sole water-soluble crystalline inorganic salt were
prepared by spray-drying aqueous slurries to the
formulations (weight %~ shown in Table 3.
Table 3
10 Examp].e 3 4 5
LAS 48.625.3 26.4
NI - 2.4 2.6
NSD (a) 48.627.7 29.0
STP 26.742.5 45.9
Salts (b) 26.742.5 45.9
Silicate 15,511.0 10.0
Minors 1.52.9 2.9
Water 7.715.9 12.2
(b):(a) 0.551.5 1.6
~ 20 kg batches o~ each powder were densified in a~ ~ Fukae (Trade Mark~ high speed mixer/granulator as
described in Examples l and 2, process con~itions and
resulting powder properties beîng shown in TabIes 4 and
5.
' ' ' '
.. . .
13227~aL
- 21 - C.3261
able 4
3 5(a)5(b)
Pulverisation:
Time (min) 3 0.50.5
Stirrer ~peed (rpm) 300 180 180
Cutter speed (rpm) 3000 3000 3000
Binder (water~:
~nount (wt %) 2 none none
Addition time tmin)
Stirrer speed (rpm) 100
Cutter speed (rpm) ~3000
Granulation:
Time (min) 5 5 6
Stirrer speed (rpm) 275 140 140
Cutter speed (rpm) 3000 2700 2700
Flow aid:
Zeo. or Alu. Alu Alu Zeo
Amount (wt %) 1 1.5 5
Addition time (min)
Stirrer speed (rpm) 90 90 90
Cutter speed (rpm) 0 300 300
Yield <1700 ~m ~wt ~) 80 94 93
~verage particle size t~m)693 528 389
Bulk density (g/litre~ 673 720 820
Dynamic flow rate (ml/s) 134 ~3 96
Compressibility l~/v) 3.5 14 11
Particle porosity<0.20 <0.20 ~0.20
~5
~322~
- 22 - C.3261
Table 5
4(a) 4(b)
5 Pulverisation:
Time tmin) 0.5 0.5
Stirrer speed (rpm) 180 180
Cutter speed lrpm) 3000 3000
Binder (water):
Amount (wt %) 1 0.5
Addition time (min) 0.5 0.5
Stirrer speed (rpm) 100 100
Cutter speed (rpm) 3000 3000
Granulation:
Time (min) 4 4
Stirrer speed (rpm) 140 140
Cutter speed (rpm) 2700 2700
Flow aid:
Zeo. or Alu. Alu Alu
Amount (wt g) 2.5 2.5
~ Addition time (min)
;~ ~ 25 Stirrer speed (rpm) 90 90
Cutter speed (rpm) 300 300
Yield C1700 ~m (wt %)95 96
30 Average particle size (~m~5dl 608
Bulk density (g/litre)830 770
Dynamic flow rate (ml/s)86 B9
Comprassibility t%v/v~ 9 11
35 Particle porosity<0.20 <0.20
~22~
- 23 - C.3261
Examples 6 to 8
Powders containing sodium tripolyphosphate, sodium
carbonate and sodium sulphate were prepared to the
formulations ~weight ~) shown in Table 6.
Table_6
Example 6 7 8
LAS 28.0 15.0 15.5
NI - 3.0 1.5
NSD (a) 28~0 18.0 17.0
STP 27.0 30.0 26.0
Carbonate 5.0 10.0 18.9
Sulphate 15.0 lS.0 17.2
Salts (b) 47.0 55.0 62.
20 Soap - 6.0
Silicate 8,0 9.0 9OO
Calcite 5.0
Minors 1.0 1.0 1.4
Water 11.0 11.0 9.8
~b):(a) 107 3~0 3.7
The powders were prepared by spray-drying aqueous
slurries. However, the sodium carbonate in the powder
of Example 6 was not incorporated via the slurry ~t
postdosed in the Fukae mixer.
20 kg batches of each powder were densified in a
Fukae (Trade Mark) ~igh~speed mixer/granulator as
described in Examplés 1 and 2, proce~s conditions and
resulting powder properties being shown in Table 7.
~227~
~ 24 - C.3261
Ta~b~e 7
6 7
Pulverisation:
Time (min)
Stirrer speed (rpm) 300 300
Cutter speed (~pm) 3000 3000
Binder (water):
Amount (wt %)0.5
Addition time (min) 2
Stirrer speed (rpm) 100 100
Cutter speed (rpm) 3000 3000
Granulation:
Time tmin) 4 4
Stirrer speed (rpm) 225 200
Cutter speed (rpm) 3000 3000
Flow aid:
Zeo. or Alu. Alu Alu
Amount (wt %)
Addition time (min)
Stirrer spsed ~rpm) 90 90
Cutter speed (rpm) 0 0
Yiald ~1700 ~m Iwt ~) g g
Average partîcle size l~m) 743 582
:
Bulk density (g/litre~ 906 800
Dynamic flow rate (ml/s) 133 120
Compressibility (%v/v) 3.5 7.0
Par icle poro~ity<0.20 ~0.20
~22~
- 25 - C.3261
Table 8
8(a) 8(b~ 8(c)
5 Pulverisation: none none none
Time (min) - - -
Stirrer speed (rpm) - -
Cutter speed (rpm) - - -
Binder (water):
Amount (wt ~) 1.5 1~5
Addition time ~min)0.5 0.5 0~5
Stirrer speed (rpm)lO0 100 100
Cutter speed (rpm) 3000 3000 3000
Gramllation:
Time (min) 10 7 7
Stirrer speed (rpm) 140 140 140
Cutter speed (rpm) 2700 2700 2700
Flow aid:
~eo or Alu Alu Alu Alu
Amount (wt %)1.5 1.5
Addition time (min3 0O5 0.5
Stirrer speed:(rpm) 90 90 90
Cutter speed (rpm) 300 300 300
Yield <1700 ~m (wt %l 94-5 9~ 9
: 30
Bulk density (g/litre~ 920 870 760
Dynamic flow rate (ml/s) g g g
Compressibility (%v/v~ g g g
Particle porosity~0.20 ~0.20 <0.20
~32~
- 26 - C.3261
Examples 9 and 10
Powders containin~ sodium tripolyphosphate and
sodium carbonate were prepared, by spray-drying aqueous
slurries, to the formulations (weight %) shown in Table
9, and densified in the Fukae mixer as in previous
Examples, as shown in Table 10.
Table 9
Example 9 10
LAS 38.0 22.7
NI 2.1
NSD (a) 38.0 24.8
STP 21.0 37.1
Carbonate 22.0 17,5
Salts (b) 43.0 54.6
2~
Silicate 12.0 9.3
Minors 1.0 1.0
Water 6.0 10.3
25 (b):(a~ 1.1 2.2
~227~
- 27 - C.3261
Table 10
9 10
5 Pulverisation:
Time (min) 3 3
Stirrer speed (rpm) 300 300
Cutter speed (rpm) 3000 3000
~inder (water):
Amount (wt ~ 2
Addition time (min)
Stirrer speed (rpm) 100 100
Cutter speed (rpm) 3000 3000
Granulation:
Time (min) 5 5
Stirrer speed (rpm) 275 275
Cutter speed (rpm) 3000 3000
Flow aid:
Zeo or Alu Alu Alu
: Amount (wt ~) 1 1
~ Addition time (min)
: 25 Stirrer speea (rpm) 90 90
Cutter speed (rpm) 0 0
Yield <1700 ~m (wt %)80 90
30 ~ Average particle size (~m) 810 566
Bulk density (g/litre) 746 801
Dynamic flow rate (ml/s) 137 . 122
Compressibility (~vlv) 3.0 10
Particle porosity ~0.20 <0O20
~2 2J~
- 28 - C.3261
Example 11
A powder containing sodium tripolyphosphate, sodium
sulphate and borax was prepared to the formulation
(weight %~ shown in Table 11.
Table 11
LAS 28.0
NSD ~a) 28.0
STP ~7 o
Sulphate 19~7
Borax 10.0
Salts (b) 56.7
Polyacrylate polymer 4.5
Minors 0.8
Water 10.0
(b):(a) 2.0-~
The powder was prapared by spray-drying an aqueous
: s7urry of all the ingredients except the borax. 9.0 kg
of spray-dried base powder and 1.0 kg of borax were mixed
and granulatedjdensified in the Fukae mixer, process
conditions and resulting powder properties being shown in
: : Table 12~
:~ 3 ~
- 29 - C.3261
Table 12
Mixing:
Time (min~ 5
Stirrer speed (rpm~ 200
Cutter speed (rpm~ 0
Binder (water):
Amount (wt %)
Addition time (min)
Stirrer speed (rpm) 300
Cuttex speed (rpm~ 3000
Granulation:
Time ~min) 9
Stirrer speed (rpm) 300
Cuttex speed (rpm) 3000
Breakdown of oversize:
Time (min) 1.5
Stirrer speed (rpm) 75
Cutter speed (rpm) 3000
.
Flow a1d:
Zeo or Alu Alu
Amount jwt ~) 1
Addition time Imin) O . 5
Stirrer speed IrPm) 75
Cutter speed (rpm) 0
Di~charge:
Time (min) 0.5
Stirrer speed (rpm) 75
Cutter speed (rpm) 0
~ 3 2 ~
- 30 - C.3261
During granulation the temperature rose from an
initial 20C to about 40-45C. It was not necessary to
cool the mixer.
The properties of the densified granulate were as
follows:
Yiela <1700 ~m (wt %)82.l
Average particle size (~m) 583
lD ~3u~X den~ity l~litre) ~B7
Dynamic flow rate (ml/s) l40
Compress ibiL ity ~v /v 1 4 . 7
Particle porosity <0O20
The product was a mild detergent powder giving a pH
(l wt~ a~ueous solution1 f 9-~
,
