A New or Improved Process of Electrically Treating Various Materials for the Purpose of Waterproofing them.
Year: 1896

page_text: Date of Application, 21st Apr., 1896-Accepted, 12th Dec., 1898
COMPLETE SPECIFICATION.
A New or Improved Process of Electrically Treating Various
Materials for the Purpose of Waterproofing them.
I, CHARLES MELBOURNE WHITE of 27 Southampton Buildings in the County
of Middlesex Patent Agent do hereby declare the nature of this invention, a
communication to me from abroad by The Electro Water Proofing and Dye Fixing
Company, a corporation organized under the lawe of the State of West Virginia
in the United States of America and having its principal placo of business at New
York in the County and State of New York in the said United States of America
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
The invention consists in a novel treatment of fabrics, threads yarn, cords, or
ropes of cotton, wool, silk or other animal aud vegetable substancos in the shape
of fabrics or otherwise, by an electric current passing from a metallic conductor
placed against one side of the goods when wet, through the said goods and to a
conductor of metal or carbon placed against the other side of the same, whereby
they are rendered water repellent.
I will refer to the sides of the goods being treated as positive and negative. By
the "positive side" of the goods is meant that side which is to be against the plate
or roller connected with the carbon of the battery (the negative element) or the
like pole of a dynamo. By the "negative side" of the goods is meant that side
of the goods which is against the conductor connected to the zinc (the positive
element) of a battery, or the equivalent pole of a dynamo.
In the practice of the process the procedure is as follows:-
The goods which it is desired to treat, say, cotton sheeting, for example, are
immersed in and wetted with water which is preferably neither alkaline or acid.
The wetted fabric is then placed between two conductors; the one on the negative
side may be of metal or carbon, or any material which is a conductor of electricity,
the one on the positive side must be a metal capable of being oxidized, preferably
aluminum or tin. The conductors, if they are in the shape of plates, should be
accurately made, so that their opposing surfaces will press upon the goods at all
points. Their shape is immaterial so long as this condition is present. If the
conductors are rollers, they should be accurately turned so as to bear upon the
goods at all points along their length. A current of electricity is now passed from
the positive side through the goods to the negative side. This current of elec-
tricity will, if of the proper strength, and if applied for the proper time and when
the conductors are pressing on the goods, confer upon said goods certain desirable
properties or characteristics among which may be particularly mentioned that it
will produce a peculiar waterproofed or water repellent effect thereon, which will
be observed when the goods after being dried are again immersed in water. After
the electrical treatment the goods are to be removed from between the conductors,
which are not to be at any time during the operation in contact or short circuited
and the suid goods are then to be dried in the air of preferably a heated room or
in an oven. It will be found that the goods are waterproofed, or the fibres thereof
are made water repellent, at.those points where the conductors were pressed upon
them and where the current passed. This waterproofing is produced, it is believed, by
the formation on the positive conductor of a metallic oxide of some kind produced
by the liberation of nascent oxygen on the said positive conductor due to the
electrolytic action of the current on the water with which the goods are saturated,
and which oxide enters into the goods or the fibres of the goods aided by the
-

page_text: current and probably is combined partly chemically and partly mechanically with
the fibres, thereby making the same waterproof or water repellent by the presence
of the oxide in or on the fibre or in or on the goods. The strength of the
current applied will depend upon the character of the goods submitted to
treatment satisfactory results have been produced with cotton cloth using one volt,
and also with 100 volts, the period of treatment being shortened by the increased
voltage of the current. Voltages have likewise been used between these two
extreme limits, and have had most satisfactory results with small conductors, say,
plates two inches in diameter using a current of 30 volts. Each specific piece of
goods offers a different resistance to the passage of the current when in a wet
condition; and different goods require different strengths of current. The theory,
as it is understood, of the process is that the water absorbed by the fibres or the
goods is electrolized by the action of the curreut, nascent oxygen is produced on
the metal plate or roller on the positive side of the goods and which is connected
with the negative pole of the battery or dynamo (or that which furnishes tho
positive current) and nascent bydrogen is liberated on the negative plate or roller
(which is connected to the positive element).
The nascent oxygen acts on the metal plate or roller on the positive side of the
goods forming some oxide of this metal, this oxide is carried into or onto the
fibres in the direction of the flow of the current combining probably with
the goods, or the fibres of the goods, and forming with or on the fibres a product
which renders the various fibres composing the goods and thus the goods themselves
waterproof or water repellent. It is not known for certain whether the oxide is
mechanically or chemically combined with the fibres, but it is thought that both effects
are obtained. The nascent hydrogen on the negative side will, if the time of treatment
is too leng, accumulate and then begin to act as a reducing agent and in case the
period of treatment is prolonged beyond the proper time then the nascent hydrogen
will reduce the oxide of the metal in or on the goods to the metallic state and the
combination or union of the oxide with the fibres will be destroyed by the reduc-
tion of the oxide to a netallic state. When the goods are dried after a treatment
prolonged beyond the normal and immersed in water they absorb the same, in
some instances, as readily as if not treated at all. The treatment must be stopped
by breaking the current at the proper moment within certain limits, for a further
continuance of the current will defeat the desired object, and the goods will cease
to be water repellent when dried, as the hydrogen will have reduced the oxide of
the metal used. A treatment of the goods for a period of time which is in excess
of that which is required to waterproof them will leave upon the goods the
reduced oxide in metallic form; and when this takes place, the goods are not
waterproofed. The treatment whon properly done, and if aluminum or tin are
used on the positive side, leaves scarcely any perceptible mark upon the goods,
sometimes the oxide being slightly visible when the goods are held up to the
light.
It is very advantageous to place a sheet of fabric such as cotton cloth around
the roller or on the plate on the negative side. By the use of this fabric the
evolved hydrogen is mechanically kept from rapidly affecting the oxide in the
cloth to be waterproofed, which latter is placed between this sheet of fabric and
the plate or roller on the positive side of the goods; and in this way the period of
treatment may be prolonged and the operation rendered less delicate and such
exactness is not then required as to time, and the general result is improved.
This sheet of fabric may be continuously used until it is worn out and if at any
time it is dried is found not to be waterproofed. The fabric treated should have
only a sufficient amount of oxide in it to make it waterproof.
The proper strength of current varies with each specific material, its thickness,
the time the treatment is to occupy, and the amount of pressure exerted on the
goods by the conductors.
A practical test must be made with each new sample of goods and the current
which it is proposed to use to determine the time of treatment, with the current and

page_text: pressure to be employed. The operator observing how long a time is required to
produce the best effect, and when he perceives an accumulation of material on the
surface of the goods, either as an oxide or as a metal, he will know that the
treatment has been too long, and will reduce the time or current until the desired
result is obtained, and only so much oxide has been formed and carried into the
goods as will waterproof the same. If an ammeter be placed in circuit the
operator will notice when the current is first made and passed through the goods,
his needle shows a sudden rise indicating a passage of the current through the
goods. It will then fall (due, it is presumed, to the formation of oxide and gases);
and then if the current is still kept on it will again, in cases where tin and
aluminum are used, begin to rise again. This, it is supposed, is due to the fact
that the oxide is being reduced to the metallic state by the evolved hydrogen; and
the current, it has been usually found, should be broken when the needle shows a
tendency to rise, or first begins to ascend, after the previous fall. With tin and
aluminum plates, it has been found to be a good test of the time of treatment
under the conditions present when the test is made. The operator may also in
order to determine the time necessary with any specific current, or the current
with any specific time, must make a practical test; and he will fiud that satis-
factory waterproof results will be obtained when such a time of treatment is had
as the specific material requires; and, as the current and time will vary with the
goods used and with the pressure of the conductors on the goods, it is impossible
to lay down any general rule. The operator can readily determine when the
hydrogen is exerting its evil effects, by noticing at the end of the treatment
whether there is a metallic deposit on any part of the goods. He will then know,
if he finds such reduced oxide, that the goods have been treated for too long a
period of time, and this may also be true when the oxide shows itself in excess.
A test, however, for each particular sample of goods with the proposed current
and pressure should invariably be made, as the variations nuder different conditions
are so great that no rule can be given which would be correct for all strength of
current, resistance and pressure.
Very satisfactory results have been obtained with plates between two and three
inches in diameter, using 30 volts, a pressure of about 50 lbs, and the time varying
from one second to 30 secunds (preferably about 15 seconds), with various thick-
nesses of cotton cloth, such as is suitable for under-garments for example, und
various metals, as for instance, aluminum. This latter metal has given good
results under the above conditions in one second on thin cotton goods. The goods
can best be treated when the conductors press with considerable force on the
goods, though fair results can be obtained by mere contact if the current is
sufficient and plenty of time is allowed.
The plate on the positive side should be frequently wiped, in order to remove
any excess of oxide that may accumulate thereon. If the oxide is allowed to
accumulate beyond a certain point the period of treatment may be reduced, but
beyond a certain point the oxide offers such a resistance to the passage of the
current that in time no waterproofing can be done, by reason of the fact that uo
current of practical strength can be obtained through the goods. When plates
of antimony are used the current after the first moment of closing the circuit
goes down to practically nothing when wet cloth is between them. A product,
it is supposed some oxide of antimony, offering so high a resistance, is formed
which prevents the current from passing. Metals like autimony which form in
the presence of nascent oxygen an oxide or substance which so quickly prevents
the
passage of any practical amount of current cannot be used. Bismuth also is
not serviceable. The current used should be a continuous current always passing
in one direction; and it has been found to be advantageons to rapidly inake and
break the current without reversing its polarity.
If a strip of material is to be treated and plates are used they can be successively
applied. If desired the goods can be passed between one or more sets of rolle,
each set consisting of two rollers. Wiping devices may be permanently attached

page_text: to such rolls to wipe off the excess of oxide formed on the roller which bears
against the positive side of the goods. Ench set of rolls may consist of two
rollers, the roller of each set which is connected with the positivo current being of
metal; while the one on the negative side may be composed of the same or any
other metal or any convenient conductor, say carbon, the function of the rollers
on the negative side being morely to carry the current and support the goods, and
they do not contribute in any other way to the waterproofing of the goods, while
the rollers on the positive side form in connection with nascent oxygen the oxide
and are essential to the process of waterproofing for from thoir surfaces is formed
the material which renders the goods waterproof.
The metal which is preferable to use upon the positive side depends upon the
nature of the effect which it is desired to produce or the property which is to be
conferred upon the fabric. If it is desired solely to waterproof the fabric, without
etaining or coloring the same, it is preferred that the positive electrode be aluminum
or tin, but many other metals may be used.
The different metals require a different treatment as to time with the same
current and pressure.
While aluminum, tiu, or those metals in general which do not stain white cloth
noticeably are to be used when the waterproofing effect only is used, for staining
or dyeing the fabric, metals such for example as copper, iron, or silver, are to be
preferred. Such metals as copper or iron may, however, be used oven when the
sole purpose is to waterproof the cloth, provided it is a colored cloth and the
alteration in color, due to the treatment by these metals, is not considered
objectionable. Lead is not as serviceable for waterproofing as aluminum or tin,
although it allows of the passage of a great quantity of current. Zine gives fairly
good results.
The degree of pressure to which the goods should be subjected may vary within'
very large limits, but it is always advantageous to have firm contact, such as
would be obtained from a screw press or a lever, with rollers the pressure should
be regulated by bringing them forcibly together by springs and a surew or screws,
so that the goods shall be in forcible contact with the conductors at all points
where the current is passing.
As to the amount of moisture to be employed, the goods should be thoroughly
wet, though the desired result can be obtained with the goods in a damp
condition.
This process has the great merit of making the individual fibres and threads
water repellent, while the pores of the goods are in no way stopped up or closed.
Consequently, if used on clothing it would not prevent evaporation taking place
through the interstices between the threads.
It has been found to be best to wet the goods only with water.
Various acids
and metallic chlorides having been tried in the water in which the goods are wet,
but no advantageous results due to their use have been found. In goods heavily
dressed with soluble material the process is not as satisfactory for the water-
proofing substance placed on such goods can be partly removed afterwards if the
soluble dressing is soaked out; though they are water repellent so long as the
gouds are subjected only to such an amount of moisture as will not remove
the soluble dressing. In goods having a dressing or finish containing grease the
waterproofing process is difficult simply because it is difficult to wet the goods;
once thoroughly wet they can be satisfactorily waterproofed.
The water with which the goods should be wet is such as is commonly supplied
in cities, being derived from rivers, reservoirs, wells or the like, which water acts
as an electrolyte, distilled water being unsuitable for the process by reason of
its high resistance to the passage of the electric current and to its decomposition
thereby.
Besides practicing the process on cottou, linen, woollen and silk fibres it is
proposed also to apply it to string, sails of ships, sewing thread and the like;
treating such materials as they pass over a conducting roller and between such

page_text: conducting roller and one or more aluminum or tin rollers preferably, on the
positive side.
Goods thoroughly waterproofed by this process will withstand considerable.
washing, particularly if the water is not too hot.
The plate on the positive side of the fabric is the anode and the plate on the
negative side is the cathode; and they can truly be so called in this situation as
they are here used as terminals of a source or electric energy at which electrolysis.
is taking place. They have not been so designated throughout the specification as.
the terms used fully describe the devices.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The process of treating material electrically, for waterproofing, which
consists in moistening the same with water, placing it between an anode of an
oxidizable metal and a suitable cathode, and substantially in contact with the
anode, passing a current of electricity through the moistened material, oxidizing
the anode, and depositing the oxide on or in the material, substautially as
described.
2. The process of treating material electrically, for waterproofing, which.
consists in moistening the material with water, placing it between and in contact
with an anode of an oxidizable metal and a suitable cathode, passing a current of
electricity through the moistened material, oxidizing the anode, and depositing the
oxide on or in the material, substantially as described.
3. The process of treating material electrically, for waterproofing, which
consists in moistening the material with wator, pressing it between an anode of an
oxidizable metal and a suitable cathode, passing a current of electricity through
the moistened material, oxidizing the anode, and depositing the oxide on or in the-
material, substantially as described.
4. The process of treating material electrically, for waterproofing, which
consists in moistening the material with an electrolyte, placing it between an.
anode of an oxidizable metal and a suitable cathode, and substantially in contact
with the anode, passing a current of electricity through the moistened material,
oxidizing the anode, and depositing the oxide on or in the material, substantially
as described.
5. The process of treating material electrically, for waterproofing, which
consists in moistening the material with an electrolyte, placing it between and in
contact with an anode of an oxidizable metal and a suitable cathode, passing a
current of electricity through the moistened material, oxidizing the anode, and.
depositing the oxide on or in the material, substantially as described.
6. The process of treating material electrically, for waterproofing, which.
consists in moistening the material with an electrolyte, pressing it between an
anode of an oxidizable metal and a suitable catbode, passing a current of electricity
through the moistened material, oxidizing the anode, and depositing the oxide on.
or in the material, substantially as described.
7. The process of treating material electrically, for waterproofing, which
consists in moistening the material with water, placing it between and in contact
with an anode of an oxidizable metal and a cathode of conducting material
covered with an absorbent fabric such as cotton cloth, passing a current of
electricity through the material to be treated, oxidizing the anode, and depositing
the oxide on or in the material, substantially as described.
Dated this 1st iley of Abril 1896.
WHITE & WOODINGTON,
27 Southampton Buildings, London, Agents.