IMPROVEMENTS IN THE MANUFACTURE OF AND IN THE APPLI- CATION OF CERTAIN DETERGENTS.
Year: 1876

page_text: LETTERS PATENT to Carl Friedrich Claus, of 38, Great Saint Helen's, Bishops-
gate Street, London, Consulting Chemist, and Arthur Edward Gilbert Lowndes,
of 27, Queen Anne's Gate, in the County of Middlesex, Manufacturer, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF AND IN THE APPLI-
CATION OF CERTAIN DETERGENTS.'
,"
Sealed the 15th May 1877, in pursuance of an Order of the Lord Chancellor, and
dated the 16th October 1876.
.
PROVISIONAL SPECIFICATION left by the said Carl Friedrich Claus and
Arthur Edward Gilbert Lowndes at the Office of the Commissioners of Patents
on the 16th October 1876.
"
CARL FRIEDRICH CLAUS, of 38, Great Saint Helen's, Bishopsgate Street,
London, Consulting Chemist, and ARTHUR EDWARD GILBERT LOWNDES, of
27, Queen Anne's Gate, in the County of Middlesex, Manufacturer. . IM-
PROVEMENTS IN THE MANUFACTURE OF AND IN THE APPLICATION OF CERTAIN
DETERGENTS."
The neutral silicates of soda and potash are known to be excellent detergents,
because the bases, soda and potash, are contained in them in a form which resembles
that in which they are combined with fatty acids in neutral soaps, that is to say,
they are capable of yielding their cleansing properties gradually without injuring
or rotting the fabrics immersed in them, be they of wool, linen, or cotton. Such
silicates are therefore in that respect superior to the carbonates of soda or potash,
and for that reason eminently suited for domestic washing purposes; but the silicates
of soda and potash have hitherto been introduced into commerce only in the form
of fused glass or in the form of a perfectly liquid solution, and in neither of these
forms were they suited for the retail trade, through which alone they would be
likely to find their way into private households or laundries for domestic washing
purposes. In the glass form the neutral silicates are not sufficiently soluble to bo
used for the said purposes, and in the form of liquid solutions the cost of bottles
and similar packages precludes their use for the same.
Householders and laundries
have therefore been deprived of the benefit of their use, and have had to adhere to
the traditional use of carbonate of soda and such preparations, which are composed
chiefly of soda and common salt, i.e., the common washing powders.

page_text: The obstacle which has hitherto prevented the neutral silicates of soda and
potash from being brought into use in a form which allowed them to be packed
into paper parcels was the difficulty the manufacturers encountered in boiling down
or concentrating these substances to a consistency sufficient for that purpose. In
fact neutral silicate of soda was never obtained in commerce in a more concentrated
form than about 70 degrees to 75 degrees Twaddle. Every attempt to concentrate
the same by the usual means still further resulted in the silicate being burnt fast
to the bottom of the pan, and destroying the latter.
Now by our present Invention we convert for the purpose aforesaid the silicates
of soda and potash into the form of a thick jelly of such a consistency which will
allow them to be packed into paper; and our Invention further consists in the
ways and means which we employ to concentrate the solutions of the neutral
silicates to the degree required for the purpose.
We accomplish the concentration of the said liquids in various ways, that is to
Bay—
1. We evaporate the solution of the silicates of soda and potash to the desired
degree in shallow evaporating vessels heated from the bottom by very slow heat,
for instance, by means of flues covered in with tiles whilst the liquid is being
agitated down to the bottom of the pan, and constantly scraped from the bottom of
the pan by a mechanical stirring apparatus; or we 2, evaporate the liquid in shallow
pans, employing as bottom heat a steam jacket for which we prefer to use super-
heated steam, and agitate the liquid as described in 1; or 3, we evaporate the
silicate in a shallow covered-in pan by means of slow heat applied to the surface
of the liquid, constant agitation of the surface being required in that case. As the
source of heat for this arrangement we use heated air or hot gases from burning
smokeless fuel, or both alternately. The effect of carbonic acid gas on solutions
of the silicates named is to separate gelatinous silicic acid, which causes the liquid
to thicken and to become a stiff jelly thus producing the result we wish to attain.
Using the products of combustion of smokeless fuel would therefore also have the
same effect, but we prefer to make use of this agent only partially and only in
combination with evaporative heat; or 4, we force carbonic acid gas through hot
liquid solutions of the silicates. We find 5, that adding a quantity of anhydrous
carbonate of soda to the liquid silicate, and warming the same so as to dissolve in
the liquid, will also thicken and gelatinise the same sufficiently; or that 6, by dis-
solving a quantity of curd soap in the liquid we also obtained the required
consistency for packing. 7. We evaporate the silicate by passing superheated
steam or heated air or gases through the liquid, and arrange the depth of the
liquid for the steam to pass. through, so as to spend the heat inherent in the
steam or hot gas; or 8, we thicken the liquid by heating a part of the silicate
until it becomes converted into a foamy pumicestone-like mass, which we pulverize
and mix with another portion of ordinary liquid neutral silicate which will
dissolve it by degrees, and cause the whole to thicken to the required consistency;
or 9, by dissolving in the ordinary liquid neutral silicate a sufficient quantity of
anhydrous carbonate or sulphate of soda, or we add the calcined carbonate or
sulphate of soda, already by the above-named methods partially concentrated
silicates of soda or potash.
The thickened neutral silicate of soda has a tendency when packed into paper
to harden in time, so as to render it slow in dissolving in water. To prevent this
we add to the jelly during the course of manufacture a quantity of hygroscopic
salt, such as carbonate of potash, or we pack the jelly into materials impervious to
air, such as tinfoil, varnished parchment paper, or paper saturated with paraffin.
We dessicate by such of the above-described incans, which are most suitable for the
purpose, the silicates also to a dry gum-like substance, which we pulverise and
pack in the form of powder, into ordinary paper. To prevent the individual
particles of the said powder from adhering to one another and forming a cake, we
mix with it some indifferent powdered substance in order to isolate the same from
one another, such as, for instance, diminuted silica, farina, talc, fuller's earth.

page_text: And lastly. Wo dissicate the silicates in shallow trays placed in a chamber,
through which heated air or hot gases are passed to such a degree that the des-
sicatent mass may be pulverized and packed into paper,
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Friedrich Claus and Arthur Edward Gilbert Lowndes in the
Great Seal Patent Office on the 16th May 1877.
CARL FRIEDRICH CLAUS, of 38, Great Saint Helen's, Bishopsgate Street Within,
in the City of London, Consulting Chemist, and ARTHUR EDWARD GILBERT
LOWNDES, of 27, Queen Anne's Gate, in the County of Middlesex, Manufacturer.
IMPROVEMENTS IN THE MANUFACTURE OF AND IN THE APPLICATION OF CERTAIN.
DETERGENTS."
The neutral silicates of soda and potash are known to be excellent detergents,
because the bases, soda and potash, are contained in them in a form which resembles
that in which they are combined with fatty acids in neutral soaps, that is to say,
they are capable of yielding their cleansing properties gradually without injuring
or rotting the fabrics immersed in them, be they of wool, linen, or cotton. Such
silicates are therefore in that respect superior to the carbonates of soda or potash,
and for that reason eminently suited for domestic washing purposes; but the silicates
of soda and potash have hitherto been introduced into commerce only in the form
of fused glass or in the form of a perfectly liquid solution, and in neither of these
forms were they suited for the retail trade, through which alone they would be
able to find their way into private households or laundries for domestic washing
purposes. In the glass form the neutral silicates are not sufficiently soluble to be
used for the said purposes, and in the form of liquid solutions the cost of bottles
and similar packages precludes their use for the same. Householders and laundries
have therefore been deprived of the benefits of their use, and have had to adhere to
the traditional use of carbonate of soda and such preparations, which are composed
chiefly of soda and common salt, i.c., the common washing powders.
The obstacle which has hitherto prevented the neutral silicates of soda and
potash from being brought into use in a form which allowed them to be packed
into paper parcels was the difficulty the manufacturers encountered in boiling down
or concentrating these substances to a consistency sufficient for that purpose. In
fact neutral silicate of soda was never obtained in commerce in a more concentrated
form than 70 degrees to 75 degrees Twaddle. Every attempt to concentrate the
same by the usual means still further resulted in the silicates being burnt fast to
the bottom of the pan, and destroying the latter.
Now by our present Invention we convert for the purposes aforesaid the silicates
of soda and potash into the form of a thick jelly of such a consistency which will
allow them to be packed into paper; and our Invention further consists in the ways
and means which we employ to concentrate the solutions of the neutral silicates to
the degree required for the purpose.
We accomplish the concentration of the said liquids in various ways, that is to
say,
1. We evaporate the solution of the silicates of soda and potash to the desired
degree in shallow evaporating vessels heated from the bottom by very slow heat,
for instance, by means of flues covered in with tiles whilst the liquid is being
agitated down to the bottom of the pan, and constantly scraped from the bottom of
the pan by a mechanical stirring apparatus; or 2 or we evaporate the liquid in shallow
pans, employing as bottom heat a steam jacket for which we prefer to use super-
heated steam, and agitate the liquid, as described in 1; or 3, we evaporate the
silicate in a shallow covered-in pan by means of slow heat applied to the surface
of the liquid, constant agitation of the surface being required in that case. As the
source of heat for this arrangement we use heated air or hot gases from burning

page_text: smokeless fuel, or both alternately, the effect of carbonic acid gas or solutions of
the silicates named is to separate gelatinous silicic acid, which causes the liquid to
thicken and to become a stiff jelly, thus producing the result we wish to attain.
Using the products of combustion of smokeless fuel would therefore also have
the same effect, but we prefer to make use of this agent only partially, and only in
combination with evaporative heat or 4, force carbonic acid gas through hot liquid
solutions of the silicates.
5. We find that adding a quantity of anhydrous carbonate of soda to the liquid
silicate, and warming the same so as to dissolve in the liquid, will also thicken and
gelatenise the same sufficiently; or that 6, by dissolving a quantity of curd soap in
the liquid we also obtain the required for packing.
7. We evaporate the silicate by passing superheated steam or heated air or gases
through the liquid, and arrange the depth of the liquid for the steam to pass
through so as to spend the heat inherent in the steam or hot gases; or 8, we thicken
the liquid by heating a part of the silicate until it becomes converted into a
foamy pumicestone-like mass, which we pulverize and mix with another portion
of ordinary liquid a neutral silicate which will dissolve it by degrees, and cause
the whole to thicken to the required consistency; or 9, by dissolving in the
ordinary liquid neutral silicate a sufficient quantity of anhydrous carbonate of soda.
The thickened neutral silicate of soda has a tendency when packed into paper
to harden in time, so as to render it slow in dissolving in water. To prevent this
we add to the jelly during the course of manufacture a quantity of a hygroscopic salt,
such as carbonate of potash, or we pack the jelly into materials impervious to air,
such as tinfold, varnished parchment paper, or paper saturated with parafine.
10. We dessicate by such of the above-described means, which are most suitable
for the purpose, the silicates also to a dry gum-like substance, which we pulverize
and pack in the form of powder into ordinary paper. To prevent the individual
particles of the said powder from adhering to one another and forming a cake, we
mix with it some indifferent powdered substance in order to isolate the same from
one another, such as for instance silicia, farnia, cale, fullers' earth.
And, lastly. We dessicate the silicates in shallow trays placed in a chamber,
through which heated air or hot gases are passed to such a degree that the dessicated
mass may be pulverized and packed into paper.
In experimenting or practically working the various methods described, we
found the most advantageous method of dessication or evaporation of the liquid
silicate to be the application of surface heat.
We use in preference long shallow pans covered in or arched over. Into these
we allow the liquid to run in very thin layers only, and apply slow gentle heat
until the liquid has assumed the consistency either of a stiff jelly or of a dry gummy
mass capable of being ground into powder. This is raked out or got out by aper-
tures through a number of working doors or openings at each side of the pan, and
if made into the form of gum it is ground into powder and packed, the details of
such operation and plans being easily understood by practical men.
Having now described the most suitable method of carrying out our Invention
we wish it to be understood that we do not confine ourselves to the same, but
claim as our Invention, all methods enumerated for and dessicating the concen-
trating liquid silicates sufficiently to enable them to be packed into paper.
In witness whereof, I, the said Arthur Edward Gilbert Lowndes, on behalf of
myself and the said Carl Friedrich Claus, have hereunto set my hand and
seal, this Sixteenth day of May, in the year of our Lord One thousand
eight hundred and seventy-seven.
ARTHUR EDWARD GILBERT LOWNDES. (L.S.)
ARTHUR EDWARD GILBERT LOWNDES. (L.S.)