Process for preparing high bulk density detergent compositions

A process for preparation of a granular detergent composition which process comprises the steps of PA1 (i) forming a liquid feedstock comprising a liquid binder and a structurant; PA1 (ii) dosing the liquid feedstock and a solid component into a high-speed mixer/densifier, to form a granular detergent material and forming or introducing further structurant in the high-speed mixer/densifier; PA1 (iii) subsequently treating the granular detergent material in a moderate-speed granulator/densifier, whereby it is brought into or maintained in a deformable state; and PA1 (iv) drying and/or cooling the product of step (iii).

FIELD OF THE INVENTION 
The present invention relates to a process for preparing a granular 
detergent composition or component having a high bulk density and good 
powder properties. More in particular, it relates to a process for the 
continuous preparation of such detergent compositions. Furthermore, it 
relates to a granular detergent composition obtainable by the process of 
the present invention. 
BACKGROUND OF THE INVENTION 
Recently there has been considerable interest within the detergents 
industry in the production of detergent powders having a relatively high 
bulk density, for example 550 g/l and above. 
Generally speaking, there are two main types of processes by which 
detergent powders can be prepared. The first type of process involves 
spray-drying and aqueous detergent slurry in a spray-drying tower. In the 
second type of process the various components are dry-mixed and optionally 
agglomerated with liquids, e.g. nonionics. The latter kind of process is 
more suited to the production of powders having a relatively high bulk 
density. That is primarily because the chemical composition of the slurry 
used in the spray drying process markedly affects the bulk density of the 
granular product. This bulk density can only be significantly increased by 
increasing the content of relatively dense sodium sulphate. However, 
sodium sulphate does not contribute to detergency, so that the overall 
performance of the powder in the wash is thereby reduced. 
One dry-mix process suitable for production of relatively high density 
products is described in European Patent Specification EP-A-0 420 317. 
This involves reacting a liquid acid precursor of an anionic surfactant 
with an alkaline inorganic material in a high-speed mixer/densifier, 
treating the material in a moderate-speed granulator/densifier, and 
finally drying and/or cooling the material. The heat of the neutralization 
reaction between the acid surfactant precursor and the alkaline material 
is used to bring the starting material into a deformable state, and 
results in densification of the detergent composition. 
In the case of powders which also contain a nonionic surfactant, it is 
possible to "structure" the (liquid) nonionic by reacting the acid 
precursor and the alkaline material in situ i.e. by dissolving the 
precursor in the nonionic and then adding the alkaline material to the 
solution in the first stage of the process. The same structuring can be 
achieved by in situ formation of a soap during the first stage, i.e. 
substituting a fatty acid for the anionic acid precursor so that the soap 
is formed by a saponification reaction during that stage. 
One drawback of such a process is the poor i.e. broad particle size 
distribution of the resultant powder. This can be conveniently expressed 
by two measures: 
(a) The total amounts of fines (&lt;180 microns) and coarse (&gt;1400 microns) in 
the product. 
(b) The n value of the Rosin Rammler distribution. This is calculated by 
fitting the particle size distribution to an n-power distribution 
according to the following formula: 
##EQU1## 
where R is the cumulative percentage of powder above a certain size D. 
D.sub.r is the average granule size and n is a measure of the particle 
size distribution. D.sub.r and n are the Rosin Rammler fits to a measured 
particle size distribution. 
A high n value means narrow particle size distribution and low values mean 
a broad particle size distribution. 
Typically powders produced by the aforementioned kind of granulation 
process have a total coarse and fines levels of around 20%. This usually 
translates into n values around 1.5. This is a problem in processing, 
since fines need to be recycled and coarse granules may need milling. 
Further since between the range 180-1400 microns, the particle size 
distribution is broad, the powders may have a negative impact on consumer 
product perception. Particularly excessive levels of fines can lead to 
poor dispersion/dissolution characteristics in use. This is due to a 
tendency for the powder bed to gel on contact with water in the wash, 
which in turn subtracts from the total wash performance. It also leaves 
undesirable residues and causes negative interaction with sensitive 
fabrics. 
SUMMARY OF THE INVENTION 
This disadvantage has now been overcome by the present invention which 
involves incorporating a structurant for the nonionic, partly before and 
partly during the first stage of the process. The structurant may be added 
as such or formed in situ as referred to above, according to its type. 
Thus, in a first aspect, the present invention provides a process for 
preparation of a granular detergent composition which process comprises 
the steps of 
(i) forming a liquid feedstock comprising a liquid binder and a 
structurant; 
(ii) dosing the liquid feedstock and a solid component into a high-speed 
mixer/densifier, to form a granular detergent material and forming or 
introducing further structurant in the high-speed mixer/densifier; 
(iii) subsequently treating the granular detergent material in a 
moderate-speed granulator/densifier, whereby it is brought into or 
maintained in a deformable state; and 
(iv) drying and/or cooling the product of step (iii). 
In a second aspect, the invention provides a granular detergent composition 
or component prepared by this process. 
The structurant may be incorporated with the feedstock during step (i) as 
dosed structurant per se and/or the structurant may be formed in situ in 
the feedstock during step (i). It is also possible to dose additional 
structurant per se into the high-speed mixer/densifier during step (ii) 
and/or form the additional structurant in situ in the high-speed 
mixer/densifier. The structurant formed or introduced in step (ii) may be 
the same as or different from the structurant formed or introduced in step 
(i). 
As used herein, the term "structurant" means a chemical component that 
helps "structure" the liquid in the powder granules thus rendering it 
effectively immobile. The aim here is to prevent the liquid phase from 
leaking. A structurant works by enhancing the viscosity of the liquid 
phase. This could include transformation of phases, i.e. from liquid to 
liquid crystalline. Or this could include solidification. Examples of 
structurants include polymers, crystallizing agents, organic soap 
molecules, solids etc. . . . 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferably, step (i) is performed in an in-line dynamic mixer located 
within a recirculation loop. Preferably also, a heat exchanger is located 
within this loop to remove the heat of reaction of any in situ formation 
of structurant. Here, the aim is to ensure completion of reaction and 
homogeneity of the reaction product within the liquid feedstock which is 
fed with dosing uniformity of components from the dynamic 
mixer/recirculation loop to the high-speed mixer/densifier used in step 
(ii). 
Preferably, the Newtonian viscosity of the liquid feedstock fed to step 
(ii) is from 0.1 to 6 Pa.s at 60.degree. C. 
The residence time in the high-speed mixer/densifier during step (ii) is 
preferably about from 5 to 30 seconds. Moreover, the residence time in the 
moderate-speed mixer/densifier during step (iii) is preferably about from 
1 to 10 minutes. The process is preferably performed as a continuous 
process. 
Steps (ii) and (iii) may respectively be effected using a high-speed 
mixer/densifier machine followed by a separate moderate-speed 
granulator/densifier machine. Alternatively, steps (ii) and (iii) could be 
effected using a single machine operated at two speeds, first at high 
speed for mixing/densification and then at moderate speed for granulation 
densification. Suitable machines include mixers of the Fukae.RTM. FS-G 
series; Diosna.RTM. V series ex Dierks & Sohne, Germany; Pharma 
Matrix.RTM. Fielder Ltd; England; Fuji.RTM. VG-C series ex Fuji Sangyo 
Co., Japan; the Roto.RTM. ex Zanchetta & Co. srl, Italy and the 
Schugi.RTM. Flexomix granulator. 
Granular detergent compositions according to the present invention may be 
in the form of complete products ready for sale to the consumer. 
Alternatively, they may be formulated as base powders to which other 
ingredients are post-dosed. In any event such compositions preferably have 
a bulk density of 550 g/l, more preferably at least 650 g/l. 
The structurant may be added at each relevant stage in its final form. Such 
a structurant may for example be of a polymer type, such as PVA, PEG, PVP, 
polyacrylates etc. The total amount of polymer (on dry polymer basis) in 
the finished product is from 0.5%, 1% or 2% to 5%. Of this the weight 
ratio of that amount incorporated in the feedstock during step (i) is 5% 
to 85%. The rest being introduced in step (ii). Preferably the amount in 
step (i) is between 20% to 60%, more preferably between 30% and 50%. 
As mentioned above, some of the structurant may be formed in situ at each 
relevant stage. In that case, a first reactant to form the structurant may 
be incorporated in the feedstock during step (i). Then, a second reactant 
may be partially dosed during step (i) and partially, dosed during step 
(ii). The amount of the first reactant should be sufficient to react with 
all of the second reactant dosed during step (i) and the amount of the 
second reactant dosed during step (ii) which it is desired to react with 
the first reactant (it may be required to leave some of the second 
reactant unreacted to fulfil another function in the final product, e.g. 
sodium carbonate as a builder). Here "final product" means the granules 
produced at the end of step (iv). 
One example of a structurant formed in situ is an anionic surfactant formed 
by dissolving an acid precursor of that surfactant in the nonionic during 
step (i) and then dosing an alkaline inorganic material, partly during 
step (i) and partly during step (ii). 
In principle, any alkaline inorganic material can be used. However, solid 
water-soluble alkaline inorganic materials are preferred. A preferred 
material is sodium carbonate, alone or in combination with one or more 
other water-soluble inorganic materials, for example, sodium bicarbonate 
or silicate. As alluded to above, sodium carbonate can provide the 
necessary alkalinity for the wash process, but it can additionally serve 
as a detergency builder. In this case the invention may be advantageously 
used for the preparation of detergent powders in which sodium carbonate is 
the sole or principal builder. Then, substantially more carbonate will be 
present than required for the neutralization reaction with the acid 
anionic surfactant precursor. 
The liquid acid precursor of an anionic surfactant may be selected from 
linear alkyl benzene sulphonic acids, alphaolefin sulphonic acids, 
internal olefin sulphonic acids, fatty acid ester sulphonic acids and 
combinations thereof. The process of the invention is especially useful 
for producing compositions comprising alkyl benzene sulphonates by 
reaction of the corresponding alkyl benzene sulphonic acid, for instance 
Dobanoic acid ex Shell. 
Another preferred class of anionic surfactants are primary or secondary 
alkyl sulphates. Linear or branched primary alkyl sulphates having 10 to 
15 carbon atoms are particularly preferred. These surfactants can be 
obtained by sulphatation of the corresponding primary or secondary 
alcohols, followed by neutralization. Because the acid precursors of alkyl 
sulphates are chemically unstable, they are not commercially available and 
they have to be neutralized as quickly as possible after their 
manufacture. The process of the present invention is especially suitable 
for incorporating alkyl sulphate surfactants into detergent powders 
because it involves a very efficient first mixing step wherein the acid 
surfactant precursor and the solid alkaline substance are brought into 
contact with one another. In this first step a quick and efficient 
neutralization reaction is effected whereby the decomposition of the alkyl 
sulphate acid is successfully kept at a minimum. 
Another kind of structurant which may be formed in situ is a soap, formed 
by dissolving a fatty acid in the liquid binder and then dosing an alkali 
metal hydroxide, e.g. sodium or potassium hydroxide, partly during step 
(i) and partly during step (ii). 
The total amount of fatty acid used during steps (i) and (ii) preferably 
comprises sufficient to form from 0.5% to 10% by weight of the soap based 
upon the weight of the total composition obtained at the end of step (iv), 
more preferably from 2% to 6%. The weight ratio of the alkali metal 
hydroxide dosed during step (ii) relative to that dosed during step (i) is 
preferably from 1.5:1 to 3:1, more preferably from 2:1 to 3:1 and 
especially from 2.5:1 to 3:1. In any event, the preferred degree of 
pre-saponification during step (i) is from 12 to 35 mole %, more 
especially from 20 to 30 mole %. 
The liquid binder preferably comprises liquid nonionic surfactant and/or 
other liquid components. 
Any such nonionic surfactant may comprise any one or more liquid nonionics 
selected from primary and secondary alcohol ethoxylates, especially 
C.sub.8 -C.sub.20 aliphatic alcohols ethoxylated with an average of from 1 
to 20 moles ethylene oxide per mole of alcohol, and more especially the 
C.sub.10 -C.sub.15 primary and secondary aliphatic alcohols ethoxylated 
with an average of from 1 to 10 moles of ethylene oxide per mole of 
alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides, 
glycerol monoethers, and polyhydroxyamides (glucamide). 
The total amount of nonionic of the liquid binder in which the structurant 
is dissolved or formed in situ is from 10 to 50% by weight of the total 
composition formed at the end of step (iv), more especially from 15% to 
35%. 
Detergent compositions of the invention may contain, in addition to any 
nonionic surfactant dosed in step (ii) and any structurant dosed during 
steps (i) and/or (ii) formed in situ, which itself is a surfactant, one or 
more other detergent-active compounds (surfactants) which may be chosen 
from soap and non-soap anionic cationic, nonionic, amphoteric and 
zwitterionic detergent-active compounds, and mixtures thereof. These may 
be dosed at any appropriate stage before or during steps (i)-(iii) or 
post-dosed after step (iii). 
In general, any surfactant which is a solid will form part of the solid 
component and will be dosed during step (ii), unless it is a structurant 
in which case it will be dosed during step (i) or during steps (ii) and 
(iii) or correspondingly formed in situ. Any other solid materials, for 
example detergency builder will preferably be dosed during step (ii) 
and/or will be post-dosed after step (iv), as appropriate. Since the 
process of the present invention provides a product which has reactive 
humidity, percarbonate bleaches can be post-dosed. 
Turning again to surfactants, many suitable detergent-active compounds are 
available and are fully described in the literature, for example, in 
"Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, 
Perry and Berch. The preferred detergent-active compounds that can be used 
are soaps and synthetic non-soap anionic and nonionic compounds. 
Suitable anionic surfactants are well-known to those skilled in the art. 
Examples include alkylbenzene sulphonates, particularly linear 
alkylbenzene sulphonates having an alkyl chain length of C8-C15; primary 
and secondary alkyl sulphates, particularly C12-C15 primary alkyl 
sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene 
sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. 
Sodium salts are generally preferred. 
Suitable nonionic surfactants include those recited above. 
Compositions according to the present invention may also contain, in 
addition to the detergent-active compounds, a detergency builder and 
optionally bleaching components and other active ingredients to enhance 
performance and properties. These may also be dosed at an appropriate time 
during steps (i)-(iv) or post-dosed. 
The total amount of all surfactant present in the detergent composition is 
suitably from 10 to 90 wt % although amounts outside this range may be 
employed as desired. 
The detergent compositions of the invention generally also contain a 
detergency builder. The total amount of detergency builder in the 
compositions is suitably from 10 to 80 wt %, preferably from 15 to 60 wt 
%. The builder may be present in an adjunct with other components or, if 
desired, separate builder particles containing one or more builder 
materials may be employed. 
Inorganic builders that may be present include sodium carbonate, if desired 
in combination with a crystallisation seed for calcium carbonate as 
disclosed in GB-A-1 437 950. As mentioned above, such sodium carbonate may 
be the residue of an inorganic alkaline neutralising agent used to form an 
anionic structurant in situ. Other suitable builders include crystalline 
and amorphous aluminosilicates, for example zeolites as disclosed in 
GB-A-1 473 201; amorphous aluminosilicates as disclosed in GB-A-1 473 202; 
and mixed crystalline/amorphous aluminosilicates as disclosed in GB 1 470 
250; and layered silicates as disclosed in EP-B-164 514. Inorganic 
phosphate builders, for example, sodium, orthophosphate, pyrophosphate and 
tripolyphosphate, may also be present, but on environmental grounds those 
may no longer be preferred in certain geographical regions. 
Aluminosilicates, whether used as layering agents and/or incorporated in 
the bulk of the particles may suitably be present in a total amount of 
from 10 to 60 wt % and preferably an amount of from 15 to 50 wt %. The 
zeolite used in most commercial particulate detergent compositions is 
zeolite A. Advantageously, however, maximum aluminium zeolite P (zeolite 
MAP) described and claimed in EP-A-384 070 may be used. Zeolite MAP is an 
alkali metal aluminosilicated of the P type having a silicon to aluminium 
ratio not exceeding 1.33, preferably not exceeding 1.15, and more 
preferably not exceeding 1.07. 
Organic builders that may be present include polycarboxylate polymers such 
as polyacrylates, acrylic/maleic copolymers, and acrylic phosphinates; 
monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, 
glycerol mono-, di- and trisuccinates, carboxymethyloxysuccinates, 
carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, 
aminopolycarboxylates such as nitrilotriacetates (NTA), 
ethylenediaminetetraacetate (EDTA) and iminodiacetates, alkyl- and 
alkenylmalonates and succinates; and sulphonated fatty acid salts. A 
copolymer of maleic acid, acrylic acid and vinyl acetate is especially 
preferred as it is biodegradable and thus environmentally desirable. This 
list is not intended to be exhaustive. 
Especially preferred organic builders are citrates, suitably used in 
amounts of from 5 to 30 wt %, preferably from 10 to 25 wt %; and acrylic 
polymers, more especially acrylic/maleic copolymers, suitably used in 
amounts of from 0.5 to 15 wt %, preferably from 1 to 10 wt %. The builder 
is preferably present in alkali metal salt, especially sodium salt, form. 
Suitably the builder system comprises a crystalline layered silicate, for 
example, SKS-6 ex Hoechst, a zeolite, for example, zeolite A and 
optionally an alkali metal citrate. 
Detergent compositions according to the invention may also contain a bleach 
system, desirably a peroxy bleach compound, for example, an inorganic 
persalt or organic peroxyacid, capable of yielding hydrogen peroxide in 
aqueous solution. The peroxy bleach compound may be used in conjunction 
with a bleach activator (bleach precursor) to improve bleaching action at 
low wash temperatures. An especially preferred bleach system comprises a 
peroxy bleach compound (preferably sodium percarbonate optionally together 
with a bleach activator), and a transition metal bleach catalyst as 
described and claimed in EP 458 397A and EP-A-509 787. 
Powder flow may be improved by the incorporation of a small amount of an 
additional powder structurant, for example, a fatty acid (or fatty acid 
soap), a sugar, an acrylate or acrylate/maleate polymer, or sodium 
silicate which is suitably present in an amount of from 1 to 5 wt %. 
The materials that may be present in detergent compositions of the 
invention include sodium silicate; corrosion inhibitors including 
silicates; antiredeposition agents such as cellulosic polymers; 
fluorescers; inorganic salts such as sodium sulphate, lather control 
agents or lather boosters as appropriate; proteolytic and lipolytic 
enzymes; dyes; coloured speckles; perfumes; foam controllers; and fabric 
softening compounds. This list is not intended to be exhaustive. 
In step (ii) of the process, solid components of the feedstock are very 
thoroughly mixed with the liquid components by means of a high-speed 
mixer/densifier. Such a mixer provides a high energy stirring input and 
achieves thorough mixing in a very short time. 
As high-speed mixer/densifier we advantageously used the Lodige (Trade 
Mark) CB 30 Recycler. This apparatus essentially consists of a large, 
static hollow cylinder having a diameter of about 30 cm which is 
horizontally placed. In the middle, it has a rotating shaft with several 
different types of blades mounted thereon. It can be rotated at speeds 
between 100 and 2500 rpm, dependent on the degree of densification and the 
particle size desired. The blades on the shaft provide a thorough mixing 
action of the solids and the liquids which may be admixed at this stage. 
The mean residence time is somewhat dependent on the rotational speed of 
the shaft, the position of the blades and the weir at the exit opening. 
Other types of high-speed mixers/densifiers having a comparable effect on 
detergent powders can also be contemplated. For instance, a Shugi (Trade 
Mark) Granulator or a Drais (Trade Mark) K-TTP 80 may be used. 
In step (ii), the components of the feedstock are thoroughly mixed in a 
high-speed mixer/densifier for a relatively short time of about 5-30 
seconds, preferably under conditions whereby the starting material is 
brought into, or maintained in, a deformable state, to be defined 
hereafter. 
After step (ii) the detergent material still possesses a considerable 
porosity. Instead of choosing a longer residence time in the high-speed 
mixer/densifier to obtain a further bulk density increase, the process of 
the present invention provides a second processing step in which the 
detergent material is treated for 1-10 minutes, preferably for 2-5 
minutes, in a moderate-speed granulator/densifier. During this second 
processing step, the conditions are such that the powder is brought into, 
or maintained in, a deformable state. As a consequence, the particle 
porosity will be further reduced. The main differences with the first step 
reside in the lower mixing speed and the longer residence time of 1-10 
minutes, and the necessity for the powder to be deformable. 
Step (iii) can be successfully carried out in a Lodige (Trade Mark) KM 300 
mixer, also referred to as Lodige Ploughshare. This apparatus essentially 
consists of a hollow static cylinder having a rotating shaft in the 
middle. On this shaft various plough-shaped blades are mounted. It can be 
rotated at a speed of 40-160 rpm. Optionally, one or more high-speed 
cutters can be used to prevent excessive agglomeration. Another suitable 
machine for this step is, for example the Drais (Trade Mark) K-T 160. 
For use, handling and storage, the densified detergent powder must 
obviously no longer be in a deformable state. Therefore, in step (iv) the 
densified powder is dried and/or cooled. This step can be carried out in a 
known manner, for instance in a fluid bed apparatus (drying, cooling) or 
in an airlift (cooling). It is advantageous if the powder needs a cooling 
step only, because the required equipment is relatively simple and more 
economical. 
Essential for the second step and preferred for the first step of the 
process is the deformable state into which the detergent powder must be 
brought in order to get optimal densification. The high-speed 
mixer/densifier and/or the moderate speed granulator/densifier are then 
able to effectively deform the particulate material in such a way that the 
particle porosity is considerably reduced or kept at a low level, and 
consequently the bulk density is increased. 
The invention will now be explained in more detail by way of the following 
non-limiting examples.

EXAMPLES 
The following base formulation was made: 
______________________________________ 
Zeolite A24 (ex Crosfiled) 
69.6% 
Synperionic A 7EO (ex ICI) 
24.6% 
Soap 4.7% 
Rest 1% 
______________________________________ 
The Soap was formed by reaction of Fatty acid (Pristeren 4916) with a 50% 
caustic solution. Nonionic and Fatty acid premixture was made first. This 
was neutralized with the 50% caustic solution. This mixture was then fed 
to the processing stream, which consists out of the following patented 
series: Recycler (CB30 Lodiger), Ploughshare (KM300) and Niro FluidBed. 
The zeolite was fed directly to the Recycler. The binder (consisting of 
nonionic, fatty acid) was optionally preneutralized before bringing to the 
Recycler. This preneutralization step is undertaken in a suitable mixer, 
here a dynamic mixer (in line continuous homogeniser). To ensure the 
homogeneity of the reaction mixture it was partially recirculated in a 
loop consisting of a series of static mixers. 
The temperature of the mixture was 65.degree. C. The recirculation in the 
loop varied between 30-60 dm.sup.3 /min. The following levels of 
preneutralization were achieved: 
______________________________________ 
Example A 
(Reference) 
Example 1 
Example 2 
Example 3 
______________________________________ 
0% 11.7% 26.5% 35% level of 
preneutralization 
Feed to Dynamic 
Mixture 
425 425 425 425 Synperonic A 7EO 
75 75 75 75 Pristerene 4916 
0 2.7 6.1 8 50% caustic solution 
Feed to Recycler 
500 502.7 506.1 508 Binder from Dynamic 
Mixture 
1000 1000 1000 1000 Zeolite A24 
23 20.3 16.9 15 50% caustic 
______________________________________ 
All rates above in kg/hr. The CB30 was run at a rpm of 1500. 
The powders were collected after the Recycler, Ploughshare and Fluidbed. 
The physical properties of the powders were established. Particle size 
distribution were characterised by several measures. Particles were sieved 
in the fraction 0, 180, 250, 355, 500, 710, 1000, 1400, 2000 microns. The 
distribution was fitted with to a Rosin Rammler model. The Rrd values 
indicates the average particle size of the distribution and Rrn value 
indicates the average spread. Further the fraction of powder less than 180 
.mu.m shall be termed fines and greater than 1400 .mu.m considered as 
coarse. The BD of the particles was measured in a standard way as was DFR. 
The results below illustrate the advantage of Example 2 over Examples A, 1 
and 3. 
______________________________________ 
Example A 
(Reference) 
Example 1 
Example 2 
Example 3 
______________________________________ 
0% 11.7% 26.5% 35% level of 
preneutralization 
107 111 126 107 DFR (ex Ploughshare) 
845 917 828 788 BD (gms/1) (ex 
Ploughshare) 
474 531 655 509 RRd .mu.m (ex 
Ploughshare) 
1.57 1.45 3.44 1.76 RRn (ex Ploughshare) 
18.8 17.4 0.7 11.4 % less than 180 .mu.m 
0.6 2.7 3.3 3.0 % greater than 1400 
.mu.m 
______________________________________ 
These powders are then further post dosed as required to form complete 
detergent formulation. 
In the light of this disclosure, modifications of the described examples, 
as well as other examples, all within the scope of the present invention 
as defined by the appended claims will now become apparent to persons 
skilled in the art.