Year: 1898

page_text: Date of Application, 9th Nov., 1898
Complete Specification Left, 22nd June, 1899 -Accepted, 12th Aug., 1899
I, FRANÇOIS LOUIS LÉON LE FRANC, of Bosc-le-Hard, in France, Sugar Manu-
facturer, do hereby declare the nature of this invention to be as follows:-
This invention relates to an improved manufacture of corks, whereby supple,
air-tight or impermeable corks are obtained such corks not communicating any
smell or taste to liquid coming in contact with them.
The manufacture is divided into two essential parts:
1. The preparation of wood for the purpose of rendering it supple, compres-
sible, expansible and elastic.
2. The manufacture of corks out of said wood so as to render them imper-
meable to air and liquid and suitable for ensuring the preservation of liquids.
1. The preparation of wood. Numerous researches made by the inventor as
to the constituent principles of wood (cellulose, mineral substances, soluble sub-
stances, incrustating substances, etc.) have revealed new facts which induced him
to adopt the method of treatment hereinafter described.
It is well known that wood owes its strength to its incrustating substances;
it is well known that the more these substances predominate, the greater is the
strength of wood. In fact they may be compared, as to their function, to starch
in linen.
The chemical composition of these substances is very complicated and varies
according to the species of wood, but they all have a definite and specific
character. Under the name of 66
celustase," they differ from cellulose, which
may be considered as their vehicle, by a greater proportion of carbon which is
found in them in a greater molecular quantity. On this peculiarity is based the
process according to this invention.
In fact, it follows from it that it is chemically possible, by oxidation or addi-
tion of molecules of water to the carbon, not only to radically modify the con-
stitution of the celustase, but also, according as the operation is conducted in
a more or less energetic manner, gradually to eliminate it, without, however,
modifying the properties of the remaining substances.
This complicated compound may be considered as belonging to the class of
glucosides. It will be therefore understood that it may be rendered soluble
by oxidation and subsequently gradually eliminated, according to the intensity
and duration of the action.
This constitutes an important feature for the application of the new process
of the treatment of wood. The wood, by an exact treatment, is caused to lose
a certain part of its strength, enough of it being left to enable it to preserve its
structure and the rigidity of its fibres. Consequently it is rendered non-con-
tractile when dried which result has not been obtained by the methods of treat-
ment hitherto used which present the great drawback of rendering the fibres
brittle and contractile when dried.
Modus operandi. The treatment of wood either in the form of battens, poles

page_text: or preferably corks suitable for the purposes required, takes place in the follow-
ing manner:
"
The incrustating substances, that is to say, the "celustase
may be oxidised
by different chemical means such as metallic or alkaline earth oxides and
peroxides, bichromates, iodates, manganates, permanganates, sulphates, nitric
compounds, alkaline or metallic chlorides, chlorates and hypochlorates, or by
acids such as chromic, permanganic, chloric, perchloric, chlorochromic, nitric, etc.
All these compounds may be used according to the necessities of the particular
cases.
Good results are attained in these conditions, but the compound at present
preferred by the inventor is nitric acid mixed with a chlorine compound such
as, for instance, a soluble chlorate. This addition of chlorine to which particular
attention is drawn is made for the purpose of attaining quick oxidising action
and thus preventing any colouring of the wood by the treatment.
Nitric acid mixed with an alkaline chlorate is used, the strength of solution
varying with the species of wood to be treated and being determined experi-
mentally by observing as a limit the point at which no nitric oxide or fumes of
nitric acid are formed. As a rule the solution used is constituted by 100 parts
by weight of commercial nitric acid at 35° B. and by 100 parts of water in which
20 parts of chlorate of potash or soda have been previously dissolved. Then
the wood to be treated is placed in the solution in a closed vessel and in order
to cause the impregnation to quickly reach the point of saturation, a vacuum
is produced over the vessel. The duration of treatment is determined by pre-
vious experiments and varies according to the nature of the wood and degree
of suppleness to be attained. On an average the reaction ought to last about
3 hours at the temperature of 25° C. During the reaction care must be taken
to maintain the temperature as low as possible and especially to avoid a sudden
rise of temperature, in order to prevent any modification or alteration in the
cellulose.
When the "celustase" has been eliminated to a sufficient extent, the nitric
solution is drained off and immediately replaced by cold water. The lixiviation
by a current of cold water is continued until a complete neutralisation and
disappearance of the slightest traces of the reagent is effected. It is advanta-
geous to effect this lixiviation under as great a depression as possible. It is
also advisable, if it is desired to recuperate the reagent absorbed by the wood
by crystallisation after the concentration, to neutralise it as soon as the whole
of the solution has been removed, by water containing some alkaline or alkaline
earth substance. It is sufficient afterwards to continue the lixiviation until all
foreign matter has disappeared.
The solutions used for the treatment of wood, may be used again and again
for an indefinite number of times, as long as they are strengthened from time
to time.
After the oxidation, that is to say, after the transformation of its incrustating
substances, the wood may be dried without becoming deformed or contracting,
it becomes light and porous, its fibres have the appearance of long and supple
textile fibres, whilst it is nevertheless homogeneous and in a perfect state of
cohesion. It is sufficient to moisten it slightly, preferably in warm water in
order to render it so remarkably supple and elastic that it may be compressed
until its cross section is reduced by half, without tearing or breaking it, and
it resumes its original shape immediately on the cessation of the pressure.
Rendering the material impermeable. The use of wood for corking liquids
has hitherto given certain results, but they did not seem to be capable of improve-
ment for reasons that will be now explained.
Owing to its structure wood, unlike cork, cannot be used for corking purposes
except in the direction of its longitudinal fibres, its transverse fibres offering
only a very limited resistance to breaking and compression. It follows from this
that owing to capillarity, wood cannot be impermeable.

page_text: In order to make it impermeable, it is necessary to plug its vascular tissue,
if not throughout its length, at least sufficiently to prevent any liquids or gases
that may be contained in the vessel corked, from passing through it.
The inventor has found that although the introduction of an impermeable
substance into the general texture of wood, enables it to be rendered air tight,
said introduction is accompanied' by serious drawbacks when the wood is
required for corking purposes.
"
23
In fact, if a wood cork is immersed in a solution having its object to
render the wood impermeable, and this solution is forced by means of pressure
or vacuum, into the tissue in all directions, that is to say longitudinally as well
as transversely of the fibres, the wood loses all its suppleness and becomes hard,
rigid and nearly incompressible. Moreover if it is compressed by the applica-
tion of a great force, so as to reduce its cross-section--which is one of the first
conditions required for corking-the greater part of the compound will be
driven out. One is therefore met by the following defects: the cork having
lost its elasticity, necessitates the application of a great force to introduce it
into the neck, while it fits in a very imperfect manner owing to the same cause.
On the other hand, the compression causes it to lose a portion of its impregnating
substance which, though it may be harmless, becomes mixed with the liquids
in the vessel, whilst the pressing "out of said substance destroys or is liable to
destroy the impermeability of the cork."
From the preceding, and taking into consideration the conditions required
for efficient corking, it follows that the first point to be attained is the imper-
meability of the longitudinal fibres, as it is only said fibres that allow the
passage of liquids and gases, while the short or transverse fibres do not offer
any outlet as they are stopped or closed by direct contact with the neck of the
bottle.
It is on this consideration that the improved process is based, the carrying
into effect of which is as follows:-
The corks having been rendered supple and lixiviated are dried until they
just contain enough water to remain supple, or if desired, they are completely
dried and then dipped into boiling water or subjected to the action of steam,
without pressure, until they acquire the desired amount of elasticity.
Then, by means of a machine similar in principle to machines used for cork-
ing by direct pressure, but having such a number of parts as to enable it to
work very quickly or by other means the corks are introduced into metallic
sheaths, or, which is much better, into plates provided with holes of corresponding
dimensions. The sheaths or the holes in the plates may be of any depth
desired but, should be greater than the height of the corks. They are prefer-
ably tapered, their upper diameter differing from that of the cork by say
2 to 4 mm. or more, the lower diameter by say 1 to 2 mm. or more, so that the
cork uniformly fits it, is compressed and leaves only its end-surfaces free or
exposed. When all the holes of a plate (plates being preferred to sheaths, in
view of their rapidity of production) are provided with corks in the manner
described, the substance destined to fill the fibres, is introduced.
For this purpose, in a vessel which is so arranged that it may be hermetically
closed and heated and which is adapted to withstand vacuum and pressure,
the plates are arranged in layers, intervals corresponding to the requirements
of the service being left between them, care being taken to arrange them so as
to have the upper part of the cork or its head upwards.
The temperature is then raised to say 60-70° C. or more according to the
melting point of the substance used to impregnate the fibres.
A vacuum is then formed in the vessel and said substance which has been
previously melted, is introduced by suction. When all the corks are immersed,
the mass is heated to a temperature varying according to the composition of
the mixture, but being generally between 70 and 90° C. The vacuum is pro-
duced over the receptacle and maintained until the corks have absorbed a suffi-

page_text: cient quantity of the impregnating substance to render them air-tight and
impermeable.
This quantity may be determined before hand and varies with the nature of
the wood, its suppleness, humidity, composition of the mixture etc. It may be
determined experimentally such estimation being acquired by skill and practice.
The impregnation having been effected the vacuum is interrupted and the
heating stopped and the corks left for a time in the vat for the removal of air.
bubbles or steam. Then the melted mass is removed, and the plates withdrawn
and cooled. The cooling may be assisted by spraying them with cold water.
The corks are then removed from the plates, which operation is. quickly
effected by hand but still more conveniently by means of a machine,
say similar to that used for inserting them into the plates.
Amongst the substances which may be used for rendering the corks impermeable
and fluid tight may be mentioned, paraffine, stearine, wax, gums resins, natural
or artificial rubber, gutta percha etc, or a mixture of some of said substances.
A mixture giving good results is the following
I, FRANÇOIS LOUIS LÉON LE FRANC, of Bosc-le-Hard, in France, Sugar Manu-
facturer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention relates to an improved manufacture of corks, whereby supple
air-tight or impermeable corks are obtained such corks not communicating any
smell or taste to liquid coming in contact with them.
The manufacture is divided into two essential parts:
1. The preparation of wood for the purpose of rendering it supple, compres-
sible, expansible and elastic.
2. The manufacture of corks out of said wood so as to render them imper-
meable to air and liquid and suitable for ensuring the preservation of liquids.
1. The preparation of wood. Numerous researches made by the inventor as
to the constituent principles of wood (cellulose, mineral substances, soluble sub-
stances, incrustating substances, etc.) have revealed new facts which induced him
to adopt the method of treatment hereinafter described.
It is well known that wood owes its strength to its incrustating substances:
it is well known that the more these substances predominate the greater is the
strength of wood. In fact they may be compared, as to their function, to starch
in linen.
The chemical composition of these substances is very complicated and varies
according to the species of wood, but they all have a definite and specific
character. Under the name of <<
celustase," they differ from cellulose, which
may be considered as their vehicle, by a greater proportion of carbon which is

page_text: found in them in a greater molecular quantity. On this peculiarity is based the
process according to this invention.
In fact, it follows from it that it is chemically possible, by oxidation or addi-
tion of molecules of water to the carbon, not only to radically modify the con-
stitution of the culustase, but also, according as the operation is conducted in
a more or less energetic manner, gradually to eliminate it, without, however,
modifying the properties of the remaining substances.
This complicated compound may be considered as belonging to the class of
glucosides. It will be therefore understood that it may be rendered soluble
by oxidation and subsequently gradually eliminated according to the intensity
and duration of the action.
This constitutes an important feature for the application of the new process
of the treatment of wood. The wood, by an exact treatment, is caused to lose
a certain part of its strength, sufficient being left to enable it to preserve its
structure and the rigidity of its fibres. Consequently it is rendered non-con-
tractile when dried which result has not been obtained. by the methods of treat-
ment hitherto used which present the great drawback of rendering the fibres
brittle and contractile when dried.
Modus operandi. The treatment of wood either in the form of battens, poles
or preferably corks suitable for the purposes required, takes place in the follow-
ing manner:
<
و"
The incrustating substances, that is to say the celustase may be oxidised
by different chemical means such as metallic or alkaline earth oxides and
peroxides, bichromates, iodates, magnanates, permangates, sulphates, nitric
compounds, alkaline or metallic chlorides, chlorates and hypochlorates, or ozone or
by acids such as chromic, permanganic, chloric, perchloric, chloro-chromic, nitric
etc. All these compounds may be used according to the necessities of the particular
cases.
Good results are attained in these conditions, but the compound at present
preferred by the inventor is nitric acid mixed with a chlorine compound such
as, for instance a soluble chlorate. This addition of chlorine to which particular
attention is drawn is made for the purpose of attaining a quick oxidising action
and thus preventing any colouring of the wood by the treatment.
Nitric acid mixed with an alkaline chlorate being used, the strength of solution
will vary with the species of wood to be treated and may be determined experi-
mentally by observing as a limit the point at which no nitric oxide or fumes of
nitric acid are formed. As a rule the solution used is constituted by 100 parts
by weight of commercial nitric acid at 35° B and 100 parts of water in which
20 parts of chlorate of potash or soda have been previously dissolved. Then
the wood to be treated is placed in the solution in a closed vessel and in order
to cause the impregnation to quickly reach the point of saturation, a vacuum
is produced in the vessel. The duration of treatment is determined by pre-
vious experiments and varies according to the nature of the wood and degree
of suppleness to be attained. On an average the reaction ought to last about
3 hours at a temperature of 25° C. During the reaction care must be taken
to maintain the temperature as low as possible and especially to avoid a sudden
rise of temperature, in order to prevent any modification or alteration in the
cellulose.
When the "celustase" has been eliminated to a sufficient extent, the nitric
solution is drained off and immediately replaced by cold water. The lixiviation
by a current of cold water is continued until a complete neutralisation and
disappearance of the slightest traces of the reagent is effected. It is advanta-
geous to effect this lixiviation under as great a depression as possible. It is
also advisable, if it is desired to recuperate the reagent absorbed by the wood
by crystallisation after concentration, to neutralise it as soon as the whole
of the solution has been removed by water containing some alkaline or alkaline

page_text: earth substance. It is sufficient afterwards to continue the lixiviation until all
foreign matter has disappeared.
The solutions used for the treatment of wood may be used again and again
for an indefinite number of times, as long as they are strengthened from time
to time.
After the oxidation, that is to say, after the transformation of its incrustating
substances, the wood may be dried without becoming deformed or contracting,
it becomes light and porous its fibres have the appearance of long and supple
textile fibres, whilst, it is nevertheless homogeneous and in a perfect state of
cohesion. It is sufficient to moisten it slightly preferably in warm water in
order to render it so remarkably supple and elastic that it may be compressed
until its cross section is reduced by half, without tearing or breaking it and
it resumes its original shape immediately on the cessation of the pressure.
Rendering the material impermeable. The use of wood for corking liquids
has hitherto given certain results, but they did not seem to be capable of improve-
ment for reasons that will be now explained.
Owing to its structure wood, unlike cork, cannot be used for corking purposes
except in the direction of its longitudinal fibres its transverse fibres offering
only a very limited resistance to breaking and compression. It follows from this
that owing to capillarity wood cannot be impermeable.
In order to make it impermeable, it is necessary to plug its vascular tissue
if not throughout its length, at least sufficiently to prevent any liquids or gases
that may be contained in the vessel corked from passing through it.
The inventor has found that although the introduction of an impermeable
substance into the general texture of wood, enables it to be rendered air tight,
said introduction is accompanied by serious drawbacks when the wood is
required for corking purposes.
"
In fact if a wood cork" is immersed in a solution having for its object to
render the wood impermeable and this solution is forced by means of pressure
or vacuum, into the tissue in all directions, that is to say longitudinally as well
as transversely of the fibres, the wood loses all its suppleness and becomes hard,
rigid and nearly incompressible. Moreover if it is compressed by the applica-
tion of a great force, so as to reduce its cross-section--which is one of the first
conditions required for corking-the greater part of the compound will be
driven out. One is therefore met by the following defects: the cork having
lost its elasticity, requires the application of a great force to introduce it
into the neck, which it fits in a very imperfect manner owing to the same cause.
On the other hand, the compression causes it to lose a portion of its impregnating
substance, which through it may be harmless, becomes mixed with the liquid
in the vessel, whilst the pressing out of said substance destroys or is liable to
destroy the impermeability of the cork.
From the preceding, and taking into consideration the conditions required
for efficient corking it follows that the first point to be attained is the imper-
meability of the longitudinal fibres as it is only said 'fibres that allow the
passage of liquids and gases, while the short or transverse fibres do not offer
any outlet as they are stopped or closed by direct contact with the neck of the
bottle.
'
It is on this consideration that the improved process is based, the carrying
into effect of which is as follows:-
The corks having been rendered supple and lixiviated are dried until they
just contain enough water to remain supple, or, if desired they are completely
dried and then dipped into boiling water or subjected to the action of steam
without pressure, until they acquire the desired amount of elasticity.
Then, by means of a machine similar in principle to machines used for cork-
ing by direct pressure, but having such a number of parts as to enable it to
work very quickly or by other means the corks are introduced into metallic
sheaths or, which is much better, into plates provided with holes of corresponding

page_text: dimensions. The sheaths or the holes in the plates may be of any depth
desired but should be greater than the height of the corks. They are prefer-
ably tapered their upper diameter differing from that of the cork by say
2 to 4 mm. or more, the lower diameter by say 1 to 2 mm. or more so that the
cork uniformly fits it, is compressed and leaves only its end surfaces free or
exposed. When all the holes of a plate (plates being preferred to sheaths in
view of their rapidity of use) are provided with corks in the manner described,
the substance destined to fill the fibres is introduced.
For this purpose in a vessel which is so arranged that it may be hermetically
closed and heated and which is adapted to withstand vacuum and pressure
the plates are arranged in layers, intervals corresponding to the requirements
of the service being left between them, care being taken to arrange them so as
to have the upper part of the cork or its head upwards.
The temperature is then raised to say 60-70° C. or more according to the
melting point of the substance used to impregnate the fibres.
A vacuum is then formed in the vessel and said substance which has been
previously melted is introduced by suction. When all the corks are immersed,
the mass is heated to a temperature varying according to the composition of
the mixture, but being generally between 70 and 90° C. The vacuum is pro-
duced over the receptacle and maintained until the corks have absorbed a suffi-
cient quantity of the impregnating substance to render them air-tight and
impermeable.
This quantity may be determined beforehand and varies with the nature of
the wood its suppleness, humidity, composition of the mixture etc. It may be
determined experimentally such estimation being acquired by skill and practice.
The impregnation having been effected the vacuum is interrupted and the
heating stopped and the corks left for a time in the vat for the removal of air-
bubbles or steam. Then the melted mass is removed and the plates withdrawn
and cooled. The cooling may be assisted by spraying them with cold water.
The corks are then removed from the plates, which operation is quickly
effected by hand but still more conveniently by means of a machine,
say similar
to that used for inserting them into the plates. Amongst
the substances which may be used for rendering the corks impermeable
and fluid tight may be mentioned paraffin, stearine, wax, gums, resins natural
or artificial rubber gutta-percha, etc. or a mixture of some said substances.
A mixture giving good results is the following:-
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. A cork made from wood the incrustating substance of which has been
attacked or not by an oxidising agent (such as metallic or earth alkaline oxides,
bichromates, iodates, manganates, permanganates, sulphates, nitric compounds,
alkaline or metal chlorides, chlorates, and hypochlorites, chromic, manganic,
permanganic, chloric, perchloric, chlorochromic, nitric or other acids by
ozone or especially by nitric acid mixed with a chlorine compound) and having
its fibres charged with a suitable air and water proof material substantially
as described.
2. The manufacture of a cork of the kind described consisting in immersing
in a closed vessel the wood destined for the manufacture of the cork in an
oxidising bath preferably nitric acid mixed with a chlorine compound, a vacuum
being preferably produced in the receptacle for the purpose of increasing the

page_text: rapidity of the impregnation, the wood, after such a treatment being lixiviated
in water until it is completely neutralised and the last traces of the reagent
have disappeared, the corks made suitably elastic being placed in metallic sheaths
or in plates provided with holes of dimensions corresponding to those of the
corks and then placed in vessels in which a vacuum or pressure can be produced
to effect the charging of the fibres of the wood with a suitable air and water
proof material substantially as described.
3. In the process above described the use of paraffin, stearine, wax, resins,
natural rubber, oil derivatives, gutta-percha, or a mixture of said substances or
a mixture of oil-rubber, colophony, stearine, and paraffin, substantially as
described.
Dated thin 02nd day of Tune 1800