Note: Descriptions are shown in the official language in which they were submitted.
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REBLENDING OF DETERGENT TABLETS
Technical Field
The present invention relates to a method of reblending tablets and to
detergent
tablets suitable for this method.
Backgiround of the Invention
Detergent tablet compositions are known in the art and are understood to hold
several advantages over detergent compositions in particulate form, such as
ease of dosing, handling, transportation and storage. Consumers particularly
like
the convenience of a shaped detergent composition that they can dose via the
dispensing drawer.
Multi-phase tablet have the advantage that they allow essentially incompatible
ingredients to be formulated in a single dosage unit.' The tablet can be
designed
to keep incompatible ingredients physically separate and to sequentially
release
those ingredients. For example, it is desirable to formulate a single-dose
composition that comprises both surfactant and fabric softener. However, many
of the commonly used surfactants will form complexes with the fabric softener
materials leading to poor cleaning, poor softening and, possibly, residues on
the
fabric. Therefore, any composition comprising both materials must either be
formulated using a limited number of compatible materials or be designed to
sequentially release said ingredients, thereby avoiding the problems of
incompatibility.
Tablets are usually prepared by pre-mixing components of a detergent
composition and forming the pre-mixed detergent components into a tablet using
any suitable equipment, preferably a tablet press. Multi-phase tablets are
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typically prepared by compressing a first composition in a~tablet press to
form a
substantially planar first layer. A further detergent composition is then
delivered
to the tablet press on top of the first layer. This second composition is then
compressed to form another substantially planar second layer.
A certain number of tablets produced by any method do not meet the quality
criteria to allow them to be shipped to the trade. For example, damaged
tablets,
tablets with bad aesthetics, tablets with unacceptable levels of chemicals
etc. To
minimize costs and make efficient use of resources the rejected tablets should
be
recycled. When the tablet is of uniform composition then the rejects may
simply
be crushed up and the particulate matter added back into the premix. However,
when you have two or more different phases made from compressed particulate
material and comprising different materials, the reblend process becomes more
complicated because these phases must be separated and reblended back into
their respective premixes.
It is an object of the present invention to provide a multi-phase detergent
composition of compressed particulate material that is designed to ameliorate
the
problems associated with reblending such tablets. The present invention also
provides a method separating the phases of multi-phase detergent tablets.
Summar)i of the Invention
The present invention relates to a multi-phase detergent composition of
compressed particulate matter, wherein the geometric mean particle diameter of
one phase differs from the geometric mean particle diameter of at least one
other
phase by at least 300 pm after crushing. The phases are consequently easy to
separate and thus it is possible to avoid excessive contamination between the
phases which would cause problems for reblend operations.
The present invention also relates to a method of separating the phases of a
multi-phase detergent compositions made from compressed particulate matter,
wherein the geometric mean particle diameter of the first phase differs from
the
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geometric mean particle diameter of the second phase by at least 300 pm, said
method comprising the steps:
(a) breaking up the compressed composition into particles, and
(b) separating phases on the basis of their particle size.
The compressed particulate matter of the present invention can be in the form
of
granules, beads, noodles, pellets, and mixtures thereof. The particles are
preferably solid particles but may be, for example, liquid or gel filled
beads.
Detailed Description of the Invention
The multi-phase detergent compositions of the present invention are made from
compressed particulate matter, wherein the geometric mean particle diameter of
one phase differs from the geometric mean particle diameter of at least one
other
phase by at least 300 pm. Preferably the geometric mean particle diameter
between the phases differ by at least 500pm, more preferably at least 750pm,
even more preferably at least 1000 pm, even more preferably still by at least
1500pm.
As used herein, "geometric mean particle diameter" means the geometric mass
median diameter of a set of discrete particles as measured by any standard
mass-based particle size measurement technique, preferably by dry sieving. A
suitable sieving method is in accordance with ISO 3118 (1976). A suitable
device
is the Ro-Tap testing sieve shaker Model B using 8" sieves of selected sizes.
The detergent compositions herein can be any suitable shape such as
hexagonal, square, rectangular, cylindrical, spherical etc. Preferably, the
compositions herein are rectangular or square as this facilitates their use in
the
dispensing drawer of automatic washing machines.
The phases herein can be in any suitable arrangement. EP-A-055,100 shows
some suitable multi-phase forms. Preferably, the detergent composition herein
has two phases. These are preferably arranged in layers or, more preferably,
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with one phase inserted into a mould in the other phase. If the composition
herein comprises more than two phases it is preferred, but not essential, that
each of the phases has an geometric mean particle diameter that differs from
the
geometric mean particle diameter each of the other phases by at least 300 pm.
The present invention is particularly useful for multi-phase tablets made from
compressed particulate. Multi-phase detergent tablets are typically prepared
by
compressing a first composition in a tablet press to form a first phase. A
further
composition is then delivered to the tablet press and compressed on top of the
first phase. Preferably the principal ingredients are used in particulate
form.
Preferably the tablets are compressed at a force of less than 10000 N/cm2,
more
preferably not more than 3000 N/cm2, even more preferably not more than 750
N/cm2. Indeed, the more preferred embodiments of the present invention are
compressed with a force of less than 500 N/cm2. Generally, the compositions
herein will be compressed with relatively low forces to enable them to
disintegrate
quickly. Suitable tabletting equipment includes a standard single stroke or a
rotary press (such as is available form Courtoy~, Korsch~, Manesty~ or
Bonals~) or those described in WO-A-00/10800. Preferably the tablets are
prepared by compression in a tablet press capable of preparing a tablet
comprising a mould. Multi-phase tablets can be made using known techniques.
A preferred tabletting process using a double punch principle (also described
as
annular punches with a second core punch build within) comprises the steps of:
i) Lowering the core punch and feeding the core phase of the tablet into the
resulting cavity,
ii) Lowering the whole punch and feeding the annular phase into the
resulting cavity,
iii) Raising the core punch up to the annular punch level (this step can
happen either during the annular phase feeding or during the
compression step).
iv) Compressing both punches against the compression plate. A pre-
compression step can be added to the compression phase. At the end of
the process, both punches are at the same level.
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The tablet is then ejected out of the die cavity by raising the punch system
to the
turret head level. The order of events can change depending on the final
result
that is desired. Tablets can also be made using double punch systems (one for
the lower punch and one for the upper punch).
Another preferred form of composition herein is particulate matter contained
with
a film material, often known as a pouch. As used herein the term "pouch" means
a closed structure, made of a water-soluble film, comprising two or more
phases
of particulate matter. The pouch can be of any form, shape and material which
is
suitable to hold the composition, e.g. without allowing substantial release of
the
composition from the pouch prior to contact of the pouch to water. The exact
execution will depend on, for example, the type and amount of the composition
in
the pouch, the number of compartments in the pouch, the characteristics
required
from the pouch to hold, protect and deliver or release the phases. Preferably,
the
pouch as a whole is stretched during formation and/or closing of the pouch,
such
that the resulting pouch is at least partially stretched.
Preferred water-soluble films for use herein include polymers, copolymers, or
derivatives thereof selected from polyvinyl alcohols, polyvinyl pyrrolidone,
polyalkylene oxides, acrylamide, acrylic acid, cellulose, cellulose ethers,
cellulose
esters, cellulose amides, polyvinyl acetates; polycarboxylic acids and salts,
polyaminoacids or peptides, polyamides, polyacrylamide, copolymers of
maleic/acrylic acids, polysaccharides including starch and gelatine, natural
gums
such as xanthum and carragum. More preferably polyvinyl alcohols, polyvinyl
alcohol copolymers, and hydroxypropyl methyl cellulose (HPMC). Highly
preferred water-soluble films are films which comprise P.VA polymers and that
have similar properties to the film known under the trade reference M3630, as
sold by Chris-Craft Industrial Products of Gary, Indiana, US or PT-75, as sold
by
Aicello of Japan.
The particulate material used for making the compositions of this invention
can
be made by any particulation or granulation process. An example of such a
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process is spray drying (in a co-current or counter current spray drying
tower)
which typically gives low bulk densities of 600g/1 or lower. Particulate
materials of
higher bulk density can be prepared by a continuous granulation and
densification process (e.g. using Lodige~ CB and/or Lodige~ KM mixers). Other
suitable processes include fluid bed processes, compaction processes (e.g.
roll
compaction), extrusion, as well as any particulate material made by any
chemical
process like flocculation, crystallisation sentering, etc.
The phases herein can comprise any suitable material. The present invention is
particularly useful when the phases comprise ingredients that are essentially
incompatible with each other or have different consumer noticeable properties
such as smell or colour as this makes it important to avoid contamination
during
reblending.
Materials that are typically added to detergent compositions include, but are
not
limited to, surfactants, fabric softening agents, perfumes, chelants, suds
suppressing system, dye fixing agents, polymeric dye transfer inhibiting
agents,
fabric abrasion reducing polymers, wrinkle reducing agents, disintegration
aids,
enzymes, bleach, builders, and mixtures thereof. These are described in more
detail below
Preferably the phase with the larger geometric mean particle diameter
comprises
one or more agents selected from fabric softening agents, perfumes, suds-
suppressing system, wrinkle reducing agents, chelating agents, dye fixing
agents,
fabric abrasion reducing polymers, and mixtures thereof. More preferably the
phase with the larger geometric mean particle diameter comprises one or more
agents selected from fabric softening agents, perfumes, suds-suppressing
system and mixtures thereof.
The compositions herein preferably comprise surfactant. Any suitable
surfactant
may be used. Preferred surfactants are selected from anionic, amphoteric,
zwitterionic, nonionic (including semi-polar nonionic surfactants), cationic
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surfactants and mixtures thereof. The compositions herein preferably have a
total
surfactant level of from 0.5% to 75% by weight, more preferably from 1 % to
50%
by weight, most preferably from 5% to 30% by weight of total composition.
Detergent surfactants are well-known and fully described in the art (see, for
example, "Surface Active Agents and Detergents", Vol. I & II by Schwartz,
Perry
and Beach). Some non-limiting examples of suitable surfactants for use herein
are:
1. Essentially any nonionic surfactants useful for detersive purposes can be
included in the present detergent compositions. Preferred, non-limiting
classes of useful nonionic surfactants include nonionic ethoxylated alcohol
surfactant, end-capped alkyl alkoxylate surfactant, ether-capped
poly(oxyalkylated) alcohols, nonionic ethoxylated/propoxylated fatty alcohol
surfactant, nonionic EO/PO condensates with propylene glycol, nonionic EO
condensation products with propylene oxide/ethylene diamine adducts .
In a preferred embodiment of the present invention the detergent composition
comprises a mixed nonionic surfactant system comprising at least one low
cloud point nonionic surfactant and at least one high cloud point nonionic
surfactant.
"Cloud point", as used herein, is a well known property of nonionic
surfactants
which is the result of the surfactant becoming less soluble with increasing
temperature, the temperature at which the appearance of a second phase is
observable is referred to as the "cloud point" (See Kirk Othmer's Encyclopedia
of Chemical Technology, 3rd Ed. Vol. 22, pp. 360-379).
As used herein, a "low cloud point" nonionic surfactant is defined as a
nonionic
surfactant system ingredient having a cloud point of less than 30°C,
preferably
less than 20°C, and most preferably less than 10°C.
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Low cloud point nonionic surfactants additionally comprise a polyoxyethylene,
polyoxypropylene block polymeric compound. Block polyoxyethylene-
polyoxypropylene polymeric compounds include those based on ethylene
glycol, propylene glycol, glycerol, trimethylolpropane and ethylenediamine as
initiator reactive hydrogen compound. Certain of the block polymer surfactant
compounds designated PLURONICTM, REVERSED PLURONICTM, and
TETRONICTM by the BASF-Wyandotte Corp., Wyandotte, Michigan, are
suitable in ADD compositions of the invention. Preferred examples include
REVERSED PLURONICTM 2582 and TETRONICTM 702, Such surfactants are
typically useful herein as low cloud point nonionic surfactants.
As used herein, a "high cloud point" nonionic surfactant is defined as a
nonionic surfactant system ingredient having a cloud point of greater than
40°C, preferably greater than 50°C, and more preferably greater
than 60°C
2. Essentially any anionic surfactants useful for detersive purposes are
suitable
for use herein. These can include salts (including, for example, sodium,
potassium, ammonium, and substituted ammonium salts such as mono-, di-
and triethanolamine salts) of the anionic sulfate, sulfonate, carboxylate and
sarcosinate surfactants. Anionic sulfate surfactants are preferred.
Other anionic surfactants include the isethionates such as the acyl
isethionates, N-acyl taurates, fatty acid amides of methyl tauride, alkyl
succinates and sulfosuccinates, monoesters of sulfosuccinate (especially
saturated and unsaturated C,2-C,$ monoesters) diesters of sulfosuccinate
(especially saturated and unsaturated C6 C,4 diesters), N-acyl sarcosinates.
Resin acids and hydrogenated resin acids are also suitable, such as rosin,
hydrogenated rosin, and resin acids and hydrogenated resin acids present in
or derived from tallow oil.
Secondary alkyl sulphate surfactants are also suitable for use herein. These
include those disclosed in US-A-6,015,784. Preferred secondary alkyl
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sulphate surfactants are those materials which have the sulphate moiety
distributed randomly along the hydrocarbyl "backbone" of the molecule. Such
materials may be depicted by the structure:
CH3(CH2)~(CHOS03 M+)(CH2)mCH3
wherein m and n are integers of 2 or greater and the sum of m+n is typically
form 9 to 17, and M is a water-solublising cation. Preferred secondary alkyl
surfactants for use herein have the formula:
CH3(CH2)X(CHOS03 M+)CH3, and
CH3(CH~)y(CHOS03 M+)CHZCH3
wherein x and (y+1 ) are intergers of at least 6, and preferably range from 7
to
20, more preferably from 10 to 16. M is a cation, such as alkali metal,
ammonium, alkanolammonium, alkaline earth metal or the like. Sodium is
typically used. Secondary alkyl surfactants suitable for use herein are
described in more detail in US-A-6015784.
3. Suitable amphoteric surfactants for use herein include the amine oxide
surfactants and the alkyl amphocarboxylic acids.
4. Zwitterionic surfactants can also be incorporated into the detergent
compositions hereof. These surfactants can be broadly described as
derivatives of secondary and tertiary amines, derivatives of heterocyclic
secondary and tertiary amines, or derivatives of quaternary ammonium,
quaternary phosphonium or tertiary sulfonium compounds. Betaine and
sultaine surfactants are exemplary zwitterionic surfactants for use herein.
Suitable betaines are those compounds having the formula R(R')2N+R2CO0-
wherein R is a C6 C~$ hydrocarbyl group, each R' is typically C,-C3 alkyl, and
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R2 is a C,-C5 hydrocarbyl group. Preferred betaines are C,2 C,$ dimethyl-
ammonio hexanoate and the C,o C,$ acylamidopropane (or ethane) dimethyl
(or diethyl) betaines. Complex betaine surfactants are also suitable for use
herein.
5. Cationic ester surfactants used in this invention are preferably water
dispersible compound having surfactant properties comprising at least one
ester (i.e. -COO-) linkage and at least one cationically charged group. Other
suitable cationic ester surfactants, including choline ester surfactants, have
for
example been disclosed in US-A-4228042, US-A-4239660 and US-A-4260529.
Suitable cationic surfactants include the quaternary ammonium surfactants
selected from mono C6 C,6, preferably C6 Coo N-alkyl or alkenyl ammonium
surfactants wherein the remaining N positions are substituted by methyl,
hydroxyethyl or hydroxypropyl groups.
Preferred surfactants for use herein are selected from anionic sulphonate
surfactnats (particularly linear alkylbenzene sulphonates), anionic sulphate
surfactants (particularly C,~ C,$ alkyl sulphates), secondary alkyl sulphate
surfactants, nonionic surfactants and mixtures thereof.
A highly preferred agent for use herein is perfume. In the context of this
specification, the term "perfume" means any odoriferous material or any
material
which acts as a malodour counteractant. In general, such materials are
characterized by a vapour pressure greater than atmospheric pressure at
ambient temperatures. The perfume or deodorant materials employed herein will
most often be liquid at ambient temperatures, but also can be solids such as
the
various tamphoraceous perfumes known in the art. A wide variety of chemicals
are known for perfumery uses, including materials such as aldehydes, ketones,
esters and the like. More commonly, naturally occurring plant and animal oils
and exudates comprising complex mixtures of various chemicals components are
known for use as perfumes, and such materials can be used herein. The
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perfumes herein can be relatively simple in their composition or can comprise
highly sophisticated, complex mixtures of natural and synthetic chemical
components, all chosen to provide any desired odour.
The perfume component of the present invention may comprise an encapsulate
perfume, a properfume, neat perfume materials, and mixtures thereof.
Perfumes which are normally solid can also be employed in the present
invention.
These may be admixed with a liquefying agent such as a solvent prior to
incorporation into the particles, or may be simply melted and incorporated, as
long as the perfume would not sublime or decompose upon heating.
Perfume also encompasses the use of materials which act as malodour
counteractants. These materials, although termed "perfumes" herein, may not
themselves have a discernible odour but can conceal or reduce any unpleasant
doors. Examples of suitable malodour counteractants are disclosed in U.S.
Patent No. 3,102,101.
The perfume component may also comprise a pro-perfumes. Pro-perfumes are
perfume precursors which release the perfume on interaction with an outside
stimulus for example, moisture, pH, chemical reaction. Pro-perfumes suitable
for
use herein include those known in the art. Examples can be found in US-A-
4,145,184, US-A-4,209,417, US-A-4,545,705, US-A-4,152,272, US-A-5,139,687
and US-A-5,234,610.
The present compositions preferably comprise perfume component at a level of
from 0.05% to 15 %, preferably from 0.1 % to 10 %, most preferably from 0.5%
to
5% by weight.
It is preferred that the compositions herein comprise a disintegration aid. As
used herein, the term "disintegration aid" means a substance or mixture of
substances that has the effect of hastening the dispersion of the matrix of
the
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present compositions on contact with water. This can take the form of a
substances which hastens the disintegration itself or substances which allow
the
composition to be formulated or processed in such a way that the
disintegrative
effect of the water itself is hastened. For example, suitable disintegration
aid
include clays that swell on contact with water (hence breaking up the matrix
of
the compositions) and coatings which increase tablet integrity allowing lower
compression forces to be used during manufacture (hence the tablets are less
dense and more easily dispersed. Any suitable disintegration aid can be used
but
preferably they are selected from disintegrants, coatings, effervescents,
binders,
clays, highly soluble compounds, cohesive compounds, and mixtures thereof.
1. The compositions herein can comprise a disintegrant that will swell on
contact
with water. Possible disintegrants for use herein include those described in
the
Handbook of Pharmaceutical Excipients (1986). Examples of suitable
disintegrants include clays such as bentonite clay; starch: natural, modified
or
pregelatinised starch, sodium starch gluconate; gum: agar gum, guar gum,
locust bean gum, karaya gum, pectin gum, tragacanth gum; croscarmylose
sodium, crospovidone, cellulose, carboxymethyl cellulose, algenic acid and its
salts including sodium alginate, silicone dioxide, polyvinylpyrrolidone, soy
polysaccharides, ion exchange resins, and mixtures thereof.
2. The compositions herein can be coated. The coating can improve the
mechanical characteristics of a shaped composition while maintaining or
improving dissolution. This very advantageously applies to multi-layer
tablets,
whereby the mechanical constraints of processing the multiple phases can be
mitigated though the use of the coating, thus improving mechanical integrity
of
the tablet. The preferred coatings and methods for use herein are described
in EP-A-846,754, herein incorporated by reference. As specified in EP-A-
846,754, preferred coating ingredients are for example dicarboxylic acids.
Particularly suitable dicarboxylic acids are selected from oxalic acid,
malonic
acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid,
azelaic
acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic
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acid and mixtures thereof. Most preferred is adipic acid. Preferably the
coating
comprises a disintegrant, as described hereinabove, that will swell on contact
with water and break the coating into small pieces. Preferably the coating
comprises a cation exchange resins, such as those sold by Purolite under the
names Purolite~ C100NaMR, a sodium salt sulfonated poly(styene-
divinylbenzene) co-polymer and Purolite~ C100CaMR, a calcium salt
sulfonated poly(styene-divinylbenzene) co-polymer.
3. The compositions herein can comprise an effervescent. As used herein,
effervescency means the evolution of bubbles of gas from a liquid, as the
result of a chemical reaction between a soluble acid source and an alkali
metal
carbonate, to produce carbon dioxide gas. The addition of this effervescent to
the detergent improves the disintegration time of the compositions. The
amount will preferably be from 0.1 % to 20%, more preferably from 5% to 20%
by weight of composition. Preferably the effervescent should be added as an
agglomerate of the different particles or as a compact, and not as separate
particles.
4. Further dispersion aid could be provided by using compounds such as sodium
acetate, nitrilotriacetic acid and salts thereof or urea. A list of suitable
dispersion aid may also be found in Pharmaceutical Dosage Forms: Tablets,
Vol. 1, 2nd Edition, Edited by H. A. Lieberman et al, ISBN 0-8247-8044-2.
5. Non-gelling binding can be integrated to the particles forming the tablet
in
order to facilitate dispersion. They are preferably selected from synthetic
organic polymers such as polyethylene glycols, polyvinylpyrrolidones,
polyacetates, water-soluble acrylate copolymers, and mixtures thereof. The
handbook of Pharmaceutical Excipients 2nd Edition has the following binder
classification: Acacia, Alginic Acid, Carbomer, Carboxymethylcellulose sodium,
Dextrin, Ethylcellulose, Gelatin, Guar Gum, Hydrogenated vegetable oil type I,
Hydroxyethyl cellulose, Hydroxypropyl methylcellulose, Liquid glucose,
Magnesium aluminum silicate, Maltodextrin, Methylcellulose,
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polymethacrylates, povidone, sodium alginate, starch and zein. Most
preferred binder also have an active cleaning function in the wash such as
cationic polymers. Examples include ethoxylated hexamethylene diamine
quaternary compounds, bishexamethylene triamines or other such as
pentaamines, ethoxylated polyethylene amines, malefic acrylic polymers.
6. The compositions herein may also comprise expandable clays. As used
herein the term "expandable" means clays with the ability to swell (or expand)
on contact with water. These are generally three-layer clays such as
aluminosilicates and magnesium silicates having an ion exchange capacity of
at least 50 meq/100g of clay. The three-layer expandable clays used herein
are classified geologically as smectites. Example clays useful herein include
montmorillonite, volchonskoite, nontronite, hectorite, saponite, sauconitem,
vermiculite and mixtures thereof. The clays herein are available under various
tradenames, for example, Thixogel #1 and Gelwhite GP from Georgia Kaolin
Co., Elizabeth, NJ, USA; Volclay BC and Volclay #325 from American Colloid
Co., Skokie, IL, USA; Black Hills Bentonite BH450 from International Minerals
and Chemicals; and Veegum Pro and Veegum F, from R.T. Vanderbilt. It is to
be recognised that such smectite-type minerals obtained under the foregoing
tradenames can comprise mixtures of the various discrete mineral entities.
Such mixtures of the smectite minerals are suitable for use herein.
7. The compositions of the present invention may comprise a highly soluble
compound. Such a compound could be formed from a mixture or from a single
compound. Examples include salts of acetate, urea, citrate, phosphate,
sodium diisobutylbenzene sulphonate (DIBS), sodium toluene sulphoriate, and
mixtures thereof.
8. The compositions herein may comprise a compound having a Cohesive Effect
on the detergent matrix forming the composition. The Cohesive Effect on the
particulate material of a detergent matrix forming the tablet or a layer of
the
tablet is characterised by the force required to break a tablet or layer based
on
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the examined detergent matrix pressed under controlled compression
conditions. For a given compression force, a high tablet or layer strength
indicates that the granules stuck highly together when they were compressed,
so that a strong cohesive effect is taking place. Means to assess tablet or
layer strength (also refer to diametrical fracture stress) are given in
Pharmaceutical dosage forms : tablets volume 1 Ed. H.A. Lieberman et al,
published in 1989. The cohesive effect is measured by comparing the tablet or
layer strength of the original base powder without compound having a
cohesive effect with the tablet or layer strength of a powder mix which
comprises 97 parts of the original base powder and 3 parts of the compound
having a cohesive effect. The compound having a cohesive effect is preferably
added to the matrix in a form in which it is substantially free of water
(water
content below 10% (pref. below 5%)). The temperature of the addition is
between 10 and 80°C, more pref. between 10 and 40°C. A compound
is
defined as having a cohesive effect on the particulate material according to
the
invention when at a given compacting force of 3000N, tablets with a weight of
50g of detergent particulate material and a diameter of 55mm have their tablet
tensile strength increased by over 30% (preferably 60 and more preferably
100%) by means of the presence of 3% of the compound having a cohesive
effect in the base particulate material. An example of a compound having a
cohesive effect. is sodium diisoalkylbenzene sulphonate.
Another preferred ingredient useful in the compositions herein is one or more
enzymes. Suitable enzymes include enzymes selected from peroxidases,
proteases, gluco-amylases, amylases, xylanases, cellulases, lipases,
phospholipases, esterases, cutinases, pectinases, keratanases, reductases,
oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases,
pentosanases, malanases, (3-glucanases, arabinosidases, hyaluronidase,
chondroitinase, dextranase, transferase, laccase, mannanase, xyloglucanases,
or mixtures thereof. Detergent compositions generally comprise a cocktail of
conventional applicable enzymes like protease, amylase, cellulase, lipase.
Enzymes are generally incorporated in detergent compositions at a level of
from
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0.0001 % to 2%, preferably from 0.001 % to 0.2%, more preferably from 0.005%
to
0.1 % pure enzyme by weight of the composition. The above-mentioned enzymes
may be of any suitable origin, such as vegetable, animal, bacterial, fungal
and
yeast origin. Origin can further be mesophilic or extremophilic
(psychrophilic,
psychrotrophic, thermophilic, barophilic, alkalophilic, acidophilic,
halophilic, etc.).
Purified or non-purified forms of these enzymes may be used. Nowadays, it is
common practice to modify wild-type enzymes via protein / genetic engineering
techniques in order to optimize their performance efficiency in the detergent
compositions of the invention. For example, the variants may be designed such
that the compatibility of the enzyme to commonly encountered ingredients of
such compositions is increased. Alternatively, the variant may be designed
such
that the optimal pH, bleach or chelant stability, catalytic activity and the
like, of
the enzyme variant is tailored to suit the particular cleaning application. In
regard
of enzyme stability in liquid detergents, attention should be focused on amino
acids sensitive to oxidation in the case of bleach stability and on surface
charges
for the surfactant compatibility. The isoelectric point of such enzymes may be
modified by the substitution of some charged amino acids. The stability of the
enzymes may be further enhanced by the creation of e.g. additional salt
bridges
and enforcing metal binding sites to increase chelant stability. Furthermore,
enzymes might be chemically or enzymatically modified, e.g. PEG-ylation, cross-
linking and/or can be immobilized, i.e. enzymes attached to a carrier can be
applied. The enzyme to be incorporated in a detergent composition can be in
any
suitable form, e.g. liquid, encapsulate, prill, granulate, or any other form
according to the current state of the art.
The compositions herein preferably comprise builders. Suitable water-soluble
builder compounds for use herein include water soluble monomeric
polycarboxylates or their acid forms, homo- or co-polymeric polycarboxylic
acids
or their salts in which the polycarboxylic acid comprises at least two
carboxylic
radicals separated from each other by not more than two carbon atoms,
carbonates, bicarbonates, borates, phosphates, and mixtures thereof. The
carboxylate or polycarboxylate builder can be monomeric or oligomeric in type
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although monomeric polycarboxylates are generally preferred. Suitable
carboxylates containing one carboxy group include the water soluble salts of
lactic acid, glycolic acid and ether derivatives thereof. Polycarboxylates
containing two carboxy groups include the water-soluble salts of succinic
acid,
malonic acid, (ethylenedioxy) diacetic acid, malefic acid, diglycolic acid,
tartaric
acid, tartronic acid and fumaric acid as well as the ether carboxylates and
the
sulfinyl carboxylates. Polycarboxylates containing three carboxy groups
include,
in particular, water-soluble citrates, aconitrates and citraconates as well as
succinate derivatives such as the carboxymethyloxysuccinates described in GB-
A-1,379,241, lactoxysuccinates described in GB-A-1,389,732, amino-succinates
described in NL-A-7205873, the oxypolycarboxylate materials described in GB-A-
1,387,447. Polycarboxylates containing four carboxy groups suitable for use
herein include those disclosed in GB-A-1,261,829. Polycarboxylates containing
sulfo substituents include the sulfosuccinates derivatives disclosed in GB-A-
1,398,421, GB-A-1,398,422 and US-A-3,936,448 and the sulfonated pyrolysed
citrates described in GB-A-1,439,000. Alicyclic and heterocyclic
polycarboxylates
include cyclopentane-cis,cis,cis-tetracarboxylates, 2,5-tetrahydrofuran-cis-
dicarboxylates, 2,2,5,5-tetra-hydrofuran-tetracarboxylates, 1,2,3,4,5,6-hexane-
hexacarboxylates and carboxymethyl derivatives of polyhydric alcohols such as
sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic
acid,
pyromellitic acid and phthalic acid derivatives disclosed in GB-A-1,425,343.
Preferred polycarboxylates are hydroxycarboxylates containing up to three
carboxy groups per molecule, more particularly citrates. The parent acids of
monomeric or oligomeric polycarboxylate chelating agents or mixtures thereof
with their salts e.g. citric acid or citrate/citric acid mixtures are also
contemplated
as useful builders. Examples of carbonate builders are the alkaline earth and
alkali metal carbonates, including sodium carbonate and sesqui-carbonate and
mixtures thereof with ultra-fine calcium carbonate as disclosed in DE-A-
2,321,001. Suitable partially water-soluble builder compounds for use herein
include crystalline layered silicates as disclosed in EP-A-164,514 and EP-A
293,640. Preferred crystalline layered sodium silicates of general formula:
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NaMSiXO~+~.YHzO
wherein M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number
from 0 to 20. Crystalline layered sodium silicates of this type preferably
have a
two dimensional sheet structure, such as the so called 8-layered structure as
described in EP-A-164,514 and EP-A-293,640. Methods of preparation of
crystalline layered silicates of this type are disclosed in DE-A-3,417,649 and
DE-
A-3,742,043. A more preferred crystalline layered sodium silicate compound has
the formula 8-Na2Si205, known as NaSICS-6TM available from Hoeschst AG.
Suitable largely water-insoluble builder compounds for use herein include the
sodium aluminosilicates. Suitable aluminosilicates include the aluminosilicate
zeolites having the unit cell formula Na~[(A102)Z(Si02)y].xH20 wherein z and y
are
at least 6, the molar ratio of z to y is from 1 to 0.5 and x is at least 5,
preferably
from 7.5 to 276, more preferably from 10 to 264. The aluminosilicate material
are
in hydrated form and are preferably crystalline, containing from 10% to 28%,
more preferably from 10% to 22% water in bound form. The aluminosilicate
zeolites can be naturally occurring materials but are preferably synthetically
derived. Synthetic crystalline aluminosilicate ion exchange materials are
available under the designations Zeolite A, Zeolite B, Zeolite P, Zeolite X,
and
Zeolite HS. Preferred aluminosilicate zeolites are colloidal aluminosilicate
zeolites. When employed as a component of a detergent composition colloidal
aluminosilicate zeolites, especially colloidal zeolite A, provide ehanced
builder
performance, especially in terms of improved stain removal, reduced fabric
encrustation and improved fabric whiteness maintenance. Mixtures of colloidal
zeolite A and colloidal zeolite Y are also suitable herein providing excellent
calcium ion and magnesium ion sequestration performance.
Fabric softening agents can be used here. Any suitable softening agents may be
used herein but preferred are quaternary ammonium agents and/or a clay
softening system.
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As used herein the term "quaternary ammonium agent' means a compound or
mixture of compounds having a quaternary nitrogen atom and having one or
more, preferably two, moieties containing six or more carbon atoms. Preferably
the quaternary ammonium agents for use herein are selected from those having
a quaternary nitrogen substituted with two moieties wherein each moiety
comprises ten or more, preferably 12 or more, carbon atoms. Preferred
examples of quaternary ammonium compounds suitable for use in the
compositions of the present invention are N,N-di(canolyl-oxy-ethyl)-N,N-
dimethyl
ammonium chloride, N,N- di(canolyl-oxy-ethyl)-N-methyl,N-(2-hydroxyethyl)
ammonium methyl sulfate, N,N-di(canolyl-oxy-ethyl)-N-methyl, N-(2-
hydroxyethyl)
ammonium chloride and mixtures thereof. Particularly preferred for use herein
is
N,N-di(canolyl-oxy-ethyl)-N-methyl,N-(2-hydroxyethyl) ammonium methyl sulfate.
Although quaternary ammonium compounds are derived from "canolyl" fatty acyl
groups are preferred, other suitable examples of quaternary ammonium
compounds are derived from fatty acyl groups wherein the term "canolyl" in the
above examples is replaced by the terms "tallowyl, cocoyl, palmyl, lauryl,
oleyl,
ricinoleyl, stearyl, palmityl" which correspond to the triglyceride source
from which
the fatty acyl units are derived. These alternative fatty acyl sources can
comprise
either fully saturated, or preferably at least partly unsaturated chains.
Any suitable clay softening system may be used but preferred are those
comprising a clay mineral compound and optionally a clay flocculating agent.
If
present, shaped compositions herein preferably contain from 0.001 % to 10% by
weight of total composition of clay softening system. The clay mineral
compound
is preferably a smectite clay compound. Smectite clays are disclosed in the US-
A-3,862,058, US-A-3,948,790, US-A-3,954,632 and US-A-4,062,647. Also, EP-
A-299,575 and EP-A-313,146 describe suitable organic polymeric clay
flocculating agents.
The compositions herein can comprise chelants/heavy metal ion sequestrants.
By heavy metal ion sequestrant it is meant herein components which act to
sequester (chelate) heavy metal ions. These components may also have calcium
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and magnesium chelation capacity, but preferentially they show selectivity to
binding heavy metal ions such as iron, manganese and copper. Heavy metal ion
sequestrants are used at a level of from 0.005% to 20%, preferably from 0.1 %
to
10%, more preferably from 0.25% to 7.5% and most preferably from 0.5% to 5%
by weight of the compositions. Suitable heavy metal ion sequestrants for use
herein include organic phosphonates, such as the amino alkylene poly (alkylene
phosphonates), alkali metal ' ethane 1-hydroxy disphosphonates and nitrilo
trimethylene phosphonates. Preferred among the above species are diethylene
triamine penta (methylene phosphonate), ethylene diamine tri (methylene
phosphonate) hexamethylene diamine tetra (methyiene phosphonate) and
hydroxy-ethylene 1,1 diphosphonate. Other suitable heavy metal ion sequestrant
for use herein include nitrilotriacetic acid and polyaminocarboxylic acids
such as
ethylenediaminotetracetic acid, ethylenetriamine pentacetic acid,
ethylenediamine
disuccinic acid, ethylenediamine diglutaric acid, 2-hydroxypropylenediamine
disuccinic acid or any salts thereof. Especially preferred is ethylenediamine-
N,N'-
disuccinic acid (EDDS) or the alkali metal, alkaline earth metal, ammonium, or
substituted ammonium salts thereof, or mixtures thereof. Preferred EDDS
compounds are the free acid form and the sodium or magnesium salt or complex
thereof.
The compositions herein can comprise a suds suppressing system. Suitable suds
suppressing systems for use herein may comprise essentially any known
antifoam compound, including, for example silicone antifoam compounds, 2-alkyl
and alcanol antifoam compounds. Preferred suds suppressing systems and
antifoam compounds are disclosed WO-A-93/08876 and EP-A-705 324.
The compositions herein can comprise dye fixing agents (fixatives). These are
well-known, commercially available materials which are designed to improve the
appearance of dyed fabrics by minimising the loss of dye from the fabrics due
to
washing. Many dye fixatives are cationic and are based on quaterinised
nitrogen
compounds or on nitrogen compounds having a strong cationic charge which is
formed in situ under the conditions of usage. Cationic fixatives are available
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under various trade names from several suppliers. Representative trade names
include CROSCOLOR PMF and CROSCOLOR NOFF from Crosfield, INDOSOL
E-50 from Sandoz, SANDOFIX TPS from Sandoz, SANDOFIX SWE from
Sandoz, REWIN SRF, REWIN SRF-O and REWIN DWE from CHT-Beitlich
GmbH, Tinofix ECO, Tinofix FRD and Solfin from Ciba-Geigy.
Other suitable cationic dye fixing agents are described in "Aftertreatments
for
Improving the Fastness of Dyes on Textile Fibres", Christopher C. Cook, Rev.
Prog. Coloration, Vol. XII (1982). Dye fixing agents suitable for use in the
present
compositions include ammonium compounds such as fatty acid-diamine
condensates inter alia the hydrochloride, acetate, metosulphate and benzyl
hydrochloride salts of diamine esters. Non-limiting examples include
oleyldiethyl
aminoethylamide, oleylmethyl diethylenediamine methosulphate,
monostearylethylene diamino-trimethylammonium methosulphate. In addition,
the N-oxides of tertiary amines, derivatives of polymeric alkyldiamines,
polyamine
cyanuric chloride condensates, aminated glycerol dichlorohydrins, and mixture
thereof.
Another class of dye fixing agents suitable for use herein are cellulose
reactive
dye fixing agents. The cellulose reactive dye fixatives may be suitably
combined
with one or more dye fixatives described herein above in order to comprise a
"dye
fixative system". The term "cellulose reactive dye fixing agent" is defined
herein
as a dye fixing agent that reacts with the cellulose fibres upon application
of heat
or upon a heat treatment either in situ or by the formulator. Cellulose
reactive
dye fixatives are described in more detail in WO-A-00/15745.
The compositions herein can comprise polymeric dye transfer inhibiting agents.
If present, the shaped compositions herein preferably comprise from 0.01 % to
10
%, preferably from 0.05% to 0.5% by weight of total composition of polymeric
dye
transfer inhibiting agents. The polymeric dye transfer inhibiting agents are
preferably selected from polyamine N-oxide polymers, copolymers of N-
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vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidonepolymers or
combinations thereof.
The compositions herein can comprise fabric abrasion reducing polymers. Any
suitable fabric abrasion reducing polymers may be used herein. Some examples
of suitable polymers are described in WO-A-00/15745.
The compositions herein can comprise wrinkle reducing agents. Any suitable
wrinkle reducing agents may be used herein. Some examples of suitable agents
are described in WO-A-99/55953.
Another ingredienfi which may be present is a bleach sysfiem, such as salfis
of
percarbonates, particularly the sodium salts, and/ or organic peroxyacid
bleach
precursor, and/or transition metal bleach catalysts, especially those
comprising
Mn or Fe. It has been found that when the pouch or compartment is formed from
a material with free hydroxy groups, such as PVA, the preferred bleaching
agent
comprises a percarbonate salt and is preferably free form any perborate salts
or
borate salts. It has been found that borates and perborates interact with
these
hydroxy-containing materials and reduce the dissolution of the materials and
also
result in reduced performance. Inorganic perhydrate salts are a preferred
source
of peroxide. Examples of inorganic perhydrate salts include percarbonate,
perphosphate, persulfate and persilicate salts. The inorganic perhydrate salts
are
normally the alkali metal salts. Alkali metal percarbonates, particularly
sodium
percarbonate are preferred perhydrates herein. The composition herein
preferably comprises a peroxy acid or a precursor therefor (bleach activator),
preferably comprising an organic peroxyacid bleach precursor. It may be
preferred that the composition comprises ~ at least two peroxy acid bleach
precursors, preferably at least one hydrophobic peroxyacid bleach precursor
and
at least one hydrophilic peroxy acid bleach precursor, as defined herein. The
production of the organic peroxyacid occurs then by an in-situ reaction of the
precursor with a source of hydrogen peroxide. The hydrophobic peroxy acid
bleach precursor preferably comprises a compound having a oxy-benzene
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sulphonate group, preferably NOBS, DOBS, LOBS and/ or NACA-OBS, as
described herein. The hydrophilic peroxy acid bleach precursor preferably
comprises TAED. Amide substituted alkyl peroxyacid precursor compounds can
be used herein. Suitable amide substituted bleach activator compounds are
described in EP-A-0170386.
The composition may contain a pre-formed organic peroxyacid. A preferred class
of organic peroxyacid compounds are described in EP-A-170,386. Other organic
peroxyacids include diacyl and tetraacylperoxides, especially
diperoxydodecanedioc acid, diperoxytetradecanedioc acid and
diperoxyhexadecanedioc acid. Mono- and diperazelaic acid, mono- and
diperbrassylic acid and N-phthaloylaminoperoxicaproic acid are also suitable
herein.
Additional ingredients that may be added to the compositions herein include
optical brighteners, organic polymeric compounds, alkali metal silicates,
colourants, and lime soap dispersants.
The compositions of the present invention are preferably not formulated to
have '
an unduly high pH. Preferably, the compositions of the present invention have
a
pH, measured as a 1 % solution in distilled water, of from 7.0 to 12.5, more
preferably from 7.5 to 11.8, most preferably from 8.0 to 11.5. .
Method of Separation
The present invention includes a method of separating two or more phases of a
composition made from compressed particulate. Said method comprises the
steps:
(a) breaking up the compressed composition into particles, and
(b) separating phases on the basis of their particle size.
The compressed composition can be broken up by any suitable means but the
resulting particulate must be substantially the same particle size as the
original
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phases. That is the breaking process must be such that each phase regains a
similar geometric mean particle diameter as when it was originally added. The
composition is preferably broken using a couple of rotating cylinders with
knives
built in (Telschig's cutters and Opbouw Messen's Cru-cut~ cutters are examples
of such equipments). Then the composition is transported to a conventional
rotating sieve to allow the separation of the plastic flow packs and then to a
lump
breaking unit (for example, a Kemutec K1350 sifter) to further break down
eventual pieces of tablets which have not being broken by the cutters.
After particulation the phases of the composition (each one with a different
particle size) can be separated by any suitable means. Preferably, the
particles
are fed into a sieving machine such as the Rotex Gradex 2000~, available from
Rotex Inc., Cincinnati, OH, USA.
Once the phases are separated they can be fed back into their respective
premixes and recompressed.
Examples
A composition was prepared using the following procedure:
Firstphase:
by weight,
of total
composition
Anionic agglomerates 1 7.1
Anionic agglomerates 2 17.5
Nonionic agglomerates 9.1
Cationic agglomerates 4.6
Layered silicate 9.7
Sodium percarbonate 12.2
Bleach activator agglomerates 6.1
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Sodium carbonate 7.27
EDDS/Sulphate particle 0.5
Tetrasodium salt of Hydroxyethane 0.6
Diphosphonic acid
Soil release polymer 0.3
Fluorescer 0.2
Zinc Phthalocyanine sulphonate encapsulate0.03
Soap powder 1.2
Suds suppresser 2.8
Citric acid 4.5
Protease 1
Lipase 0.35
Cellulase 0.2
Amylase 1.1
Binder spray on system 3.05
Perfume spray on 0.1
DIBS (Sodium diisobutylbenzene sulphonate)2.1
Anionic agglomerates 1 comprise 40% anionic surfactant, 27% zeolite and 33%
carbonate
Anionic agglomerates 2 comprise 40% anionic sufactant, 28% zeolite and 32%
carbonate
Nonionic agglomerate comprise 26% nonionic surfactant, 6% Lutensit K-HD 96
ex BASF, 40% sodium acetate anhydrous, 20% carbonate and 8% zeolite.
Cationic agglomerate comprise 20% cationic surfactant, 56% zeolite and 24%
sulfate
Layered silicate comprises of 95% SKS 6 and 5% silicate
Bleach activator agglomerates comprise 81 % Tetraacetylethylene diamine
(TAED), 17% acrylic/maleic copolymer (acid form) and 2% water
EDDS/Sulphate particle particle comprise 58% of Ethylene diamineN,N-disuccinic
acid sodium salt, 23% of sulphate and 19% water.
Zinc phthalocyanine sulphonate encapsulates are 10% active
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Suds suppresser comprises 11.5% silicone oil (ex Dow Corning), 59% zeolite and
29.5% HBO
Binder spray on system comprises 0.5 parts of Lutensit K-HD 96 and 2.5 parts
of
Polyethylene glycols (PEG)
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Second phase:
by weight;
of total
composition
Softerner and perfume bead . 8.4
Perfume beads composition contains 56% expancel 091 DE80, 7% silica, 8%
perfume, 5% crosslinked polyvinylalcohol (PVA)-borate, 5% water, 18% cationic
softener N,N-di(candyl-oxy-ethyl)-N-methyl,N-(2-hydroxyethyl) ammonium methyl
sulfate and 1 % of laundry compatible Zeneca Monastral blue
MANUFACTURING:
Manufacturing of the first phase:
The detergent active composition of the first phase was prepared by admixing
the
granular components in a mixing drum for 5 minutes to create an homogenous
particle mixture. During this mixing, the spray-ons were carried out with a
nozzle
and hot air using the binder composition described above. The mean particle
diameter was 560pm.
Manufacturing of phase 2:
The beads of the second phase were manufactured using a Braun food
processor with a standard stirrer where the dry mixture described above is
added. The mixer was operated at high speed during 1 minute and the mix is
poured into a Fuji Paudal Dome Gran DGL1 (Japan) extruder with 3 mm diameter
holes in the extruder tip plate and operated at 70 revolutions per minute. The
resulting product was added into a Fuji Paudal Marumerizer QJ-230 were it is
operated at 1000 revolutions per minute for 5 minutes were a good
spheronization was achieved.
In a further step, the beads were coated by a partially insoluble coating
described. This was achieved by spraying the beads in a conventional mix drum
with 4% (weight beads based) of a mixture of 80% cross linked polyvinyl
alcohol-
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borate and 20% water at 70°C using a spray nozzle and hot air. The
beads are
then left in a rotating drum for 60 minutes and hot air was injected in order
to
evaporate part of the water contained in the PVA coating. The final water
content
in the bead is mentioned in the bead composition above. .
The resulting beads had a particle diameter of 2110 pm.
Tablet manufacturing:
The multi-phase tablet composition was prepared using an Instron 4400 testing
machine and a standard die for manual tablet manufacturing. 35g of the
detergent active composition of the first phase was fed into the dye of 41x41
mm
with rounded edges that has a ratio of 2.5 mm. The mix was compressed with a
force of 1,500 N with a punch that has a suitable shape to form a concave
mould
of 25 mm diameter and 10 mm depth in the tablet. The shaped punch was
carefully removed leaving the tablet into the dye. 4g of beads that will form
the
second phase were introduced into the mould left in the first tablet shape and
a
final compression of 1,700 N was applied to manufacture the multiphase tablet
using a flat normal punch. The tablet is then manually ejected from the dye.
In a following step, the tablet made with the process described above were
coated by manually dipping them into a molten mixture of coating at
170°C and
let them cool back to room temperature allowing the coating to harden. The
composition and percentage of the coating are described in the tablet
composition above.
An equivalent of 1 kg of flow-wrapped tablets were processed through a Opbouw
Messen cutter and then conveyed to a cylindrical rotating sieve with
10mmx10mm openings to separate the plastic flow wraps from the crushed
tablets. After the flow wrap separation, the mixture is conveyed to a Kemutec
K1350 lump breaker to covert the remaining pieces of tablet into powder.
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To classify the high particle size phase from the lower particle size phase,
the
stream is conveyed to a Rhewum WA 8/270x180V sieve with 1500x1500 pm
openings. Two streams were recuperated with this procedure: the coarse
fraction
with an geometric mean particle diameter of 2137 pm and the fine fraction of
691
pm.
These two fractions were then mixed back in the original streams at a level of
10% by weight (in each phase) and a new composition was made following the
same procedure indicated above.
29
