IMPROVED PROCESSES FOR PREPARING FUR FOR FELTING
Year: 1886

page_text: We, EDMUND TWEEDY, of Danbury, in the County of Fairfield, and State of
Connecticut, U.S.A., Manufacturer, HENRY LEFFERT BREVOORT, of New York
City, in the County of New York and State of New York, U.S.A., Mechanical
Eugineer, and ISAIAH LEWIS ROBERTS, of Brooklyn, in the County of Kings, and
State of New York, U.S.A., Electrician, do hereby declare the nature of our joint
invention for "IMPROVED PROCESSES FOR PREPARING FUR FOR FELTING," and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
Our discovery or invention relates to processes for oxidizing the water repellent
animal material upon the surface of fur fibres to put them into condition to be
subsequently felted into hats or other articles.
We have discovered in the old process of treating fur fibres with nitrate of
mercury that the effect of such treatment is to oxidize the water repellent animal
material which exists on the surface of the fibres, thus rendering such water
repellent material soluble in hot water. The object of rendering such material
soluble is to enable the hot water used in the subsequent operations of felting to
come directly in contact with the fibres so that it may have a softening action
upon them and permit them to come into more intimate contact with one another.
Our invention consists in oxidizing this water repellent material by the use of
certain agents, which, unlike nitrate of mercury, do not leave upon the fibres any
poisonous substance likely to injuriously affect the work people who manipulate
the goods in the process of felting, and in the subsequent stages of manufacture.
We effect the oxidation of the water repellent material by the use of prepared
oxidizing fumes made from a material, or materials, not upon the surface of the
fur fibres. By using such oxidizing agents, in the manner hereinafter more
particularly set forth, we produce an oxidizing effect upon the water repellent
animal material on the surface of the fur fibre and make it soluble in hot water.
We will now more particularly describe our methods of procedure.
We treat the fur, either off or on the skin, with oxidizing fumes prepared for the
purpose. In carrying out our invention we hang the skins up in a chamber, or we
spread the fur upon trays or supports placed in the chamber, such trays having
preferably sieved bottoms, and we form in the said chamber, or cause to flow into
of Deaf/1

page_text: it, oxidizing fumes, such as vaporized nitric acid, dioxide of sulphur, nitrous fumes,
etc. We prefer to use the vapor or fumes of nitric acid, which we prefer to make
by treating saltpetre with sulphuric acid, and heat in a retort outside of the
chamber, and from which retort the vapor or fumes are introduced into the
chamber. When the skins with the fur upon them, or the fur alone, after being
treated are to be removed from the chamber, we prefer, prior to such removal, to
empty the chamber of the fumes by means of a draft orifice entering into a flue or
chimney. The fur is to be submitted to the fumes or vapors for a sufficient length
of time to perform the necessary work, to wit:-to put it into such a condition
that it may be subsequently felted. This period depends upon the strength of the
fumes used. We have obtained a very satisfactory result in the following
manner:-
In a box four feet long and three feet wide, and three feet deep, we have
suspended fifty Scotch coney skins. We then shut the lid to prevent the escape of
fumes. The box was provided with an opening in the lower part which could be
shut by a plug or valve. It was also connected near the top with a pipe leading
to a chimney flue which could be closed by a damper. The neck of a retort was
inserted into a hole in the box near the top, and in the retort was placed one
pound of powdered saltpetre and one pound of sulphuric acid. The retort was
heated with a gas jet, and the vapor or fumes produced escaped from the retort
into the box for a period of eight hours, the hole and the pipe leading to the
chimney being then shut. The damper on the pipe to the flue was then opened
and the plug removed from the opening in the lower part of the box (the retort
being also removed) which caused a draft that carried off the fumes. The box was
then opened, the skins were removed, the fur was cut from them in the usual
manner, and was then felted into hats.
The fur may be exposed for varying lengths of time to the fumes, this being a
matter under the control of the operator. The stronger, or more concentrated the
fumes, and the less the admixture of atmospheric air, the shorter may be the treat-
ment; and, on the other hand, with dilute or very weak fumes there will be required
a longer treatment. By, this process it will be observed that the fur is never
brought into contact with any liquids, such as nitrate of mercury, and the like, and
that no materials are left in the fur which may prove injurious to the workmen in
the manufacture of the hat, or the felting for any usual manufacture.
Our process produces a superior article of felt. In the practice of our invention,
the material or materials from which the fumes are to be produced are of course
not to be placed upon the fur, but are to be kept separate and distinct therefrom,
the fur merely being brought in contact with the fumes produced.
We intend to produce or manufacture the fumes in various ways, and also to
produce or manufacture them in a chamber or box which contains the fur, the
precise method of carrying out the process of manufacturing the fumes being
unimportant, or merely a question of convenience, and the gist of our invention
being the subjection of the fur to intimate contact with the fumes, so that the
latter may act upon the fur or the substance which coats the fur. As we under-
stand it, some substance exists on the surface of the fur which, in its normal state,
is a water repellent, and, to enable the fur to be felted, this material must be either
removed, or so changed that hot water used in the sizing or felting operation can
come in contact with the fur itself. By our process the oxidizing fumes oxidize
this material, and it then ceases to be water repellent. However, whether our
theory be correct or not, the advantageous results herein referred to can be
obtained by practising the processes herein set forth.
By the method above described considerable time is occupied in the fuming
operation, (some seven or eight hours, or more) for the fur is only exposed to such
fumes as the air can carry, and fresh and strong fumes are not brought into contact
with the fur with rapidity during the treatment of it. The quantity of fumes, or
vapors which the air can carry is limited at various temperatures, and we have
found that when the fumes are admitted into a chamber containing air, and having

page_text: no open outlet, though the fumes may act forcibly at the beginning of the operation,
they soon give up a large part of their oxygen, and are not then replaced by fresh
and strong fumes until considerable time has elapsed, and this makes the process a
comparatively slow one. We can cause the work to be done more rapidly by
either causing the fur to pass through the fumes, or the fumes to flow in a current
past the fur, or both, the object being to have fresh and strong fumes constantly
passing about and around the fur, so that they may act thereon. We can use a
chamber in which the fumes are made or prepared, or into which they are con-
ducted, and within which the fur to be treated is placed, the said chamber having
openings in it at a suitable point or points through which the fumes may escape.
This chamber may consist of a box, or preferably of a brick or masonry room
having within it supports upon which the skins or furs may be placed, and the
fumes or vapors may be produced or prepared from material or materials heated
in a pot, or other suitable vessel, either in or outside of the chamber, and if a fire
is used the products of combustion may be conducted to a suitable chimney or
stack. At a distant point of the room from that in which the fumes are prepared
or entered, an opening or openings may be made through which the fumes may
escape into a stack, or into the open air; the relative position of the pot for
preparing the fumes, or the aperture through which they enter the chamber and
the escape openings, being such that the fumes pass the fur to be treated, and will
then pass out through the openings while their place is taken by fresh and strong
fumes. The fumes may be prepared in or conducted into a chamber through
which, on a moving endless or other belt, or like device, the fur is carried, and the
current of fumes may be in any direction with reference to the line of motion of
the belt; if the two move in the same direction it is best to give them different
velocities. We prefer to have a current of fumes, either in an opposite direction,
or at right angles to the line of movement of the fur. It is unnecessary to describe
such a structure in detail, for it may consist simply of a belt of suitable material
moving through a chamber, room, or box, in which are the fumes, and this belt
may be arranged to move horizontally, or in an inclined direction through a long
box or chamber, or vertically through an upright chamber, either plan being
capable of ready adoption.
Our invention is in nowise limited to any particular apparatus, and we do not
here claim such apparatus; but the substance of this part of our invention consists
in causing the fur and the fumes which we employ to move in relation one to the
other, thus subjecting the fur constantly to fresh and strong fumes.
We do not limit ourselves to nitric or nitrous fumes, as other oxidizing fumes
may be used which may be prepared in different ways. The material or materials
from which the fumes are to be produced are not to be placed upon the fur, but the
fur is to be in contact only with the vapors or fumes. Fur upon the pelt, or off
the pelt may be thus treated.
As we have said, we prefer to use fumes produced from the action of sulphuric
acid upon saltpetre when subjected to heat. No precise proportions are necessary,
but, for example, five pounds saltpetre may be placed in a cast iron pot, and
eight pounds of sulphuric acid may be added. When this is heated to about
250° Fahrenheit, or above, satisfactory fumes will be evolved, which will be given
off in greater quantities as the heat is increased. Fumes made in this
have found very satisfactory.
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Our theory, as above stated, is that there is some form of animal grease or fat
upon the fur fibres that it is necessary to oxidize, so that the fur fibres themselves
will be in a proper condition to be wet by the hot water used in felting. This
grease, in the process of oxidation, takes oxygen from the fumes and renders the
fumes comparatively weak and useless, and thus a constant current of fresh fumes
is desirable so as to bring fumes which are rich in oxygen in contact with the fur.
We have discovered that the action of the prepared oxidizing vapors or fumes is
much increased, if, after they are prepared, they are mingled with aqueous vapor,
either above or below the boiling point of water,

page_text: In carrying out this part of our invention we manufacture nitric or nitrous
fumes preferably, though other oxidizing fumes can be used, and we introduce with
them into the chamber, or receptacle containing the fur, a jet of steam, or we
produce aqueous vapor in the chamber itself by heating water in a vessel therein,
and we commingle the aqueous vapor and the prepared oxidizing fumes either
before or at the time the fumes come in contact with the fur. By so doing we find
that the action of the fumes upon the fur is hastened or increased in power, and
the period of treatment may be thus reduced.
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We do not confine ourselves to any precise proportion of vapor or fumes, as a
beneficial effect is attained even with a small percentage of aqueous vapor. Of
course the proportion of aqueous vapor could be increased so much that it would
dilute the oxidizing fumes so as to prevent or impair their proper action, and that
must be avoided. One part by bulk of oxidizing fumes to from one-fourth to one-
half their bulk of aqueous vapor constitutes a good mixture.
Our theory is that the artificial supply of moisture enables the oxidizing fumes
to perform their oxidizing function more rapidly, or energetically, and in practice
it certainly hastens the treatment. Whether our theory be correct or not, the
beneficial results, above described, will be attained by following the directions
given herein,
We have also discovered another method or process of producing the same result
by the use of moisture, and it consists in dampening the fur while on the skins,
either by dipping them in water, or by throwing water or a spray of water upon
it, or submitting it to contact with wet substances, or making the fur damp in any
way, and then, while in the dampened condition, submitting it to the action of the
oxidizing vapors, substantially as above described. No specific amount of moisture
is necessary, but it is advisable to thoroughly dampen the fur upon the skins while
at the same time it is not advantageous to so wet it that it becomes matted.
Advantageous results can be obtained by following these directions.
What we claim to be new and desire to secure by Letters Patent, is :—
1. Subjecting fur to prepared oxidizing fumes or vapors, substantially as
described.
2. The process of treating fur, which consists first in the manufacture of suitable
oxidizing fumes, and then, second, submitting the fur to the action of such fumes,
substantially as described.
3. The process of treating fur, which consists in subjecting it to the action of
oxidizing vapors or fumes when the fur is contained in a chamber to which the
fumes are admitted, so that they may be brought into contact with the fur to be
treated, substantially as described.
4. The process of treating fur, which consists in forming oxidizing vapors or
fumes in a suitable apparatus outside of the chamber in which the fur is placed,
and then conducting the said fumes and vapors into the chamber and permitting
them to act upon the fur contained in said chamber, substantially as described.
5. The process of treating fur, which consists in forming oxidizing fumes or
vapors, subjecting the fur in a chamber or receptacle to such vapors for the desired
length of time, then emptying the said chamber of the fumes and subsequently
removing the fur therefrom, substantially as described.
6. The process of treating fur, which consists in subjecting it to oxidizing fumes
which are the product of a material or materials not placed upon or in contact with
the fur fibres themselves, substantially as described.
7. The process of treating fur, which consists of the following steps, first placing
the fur in a chamber or receptacle, second, closing the said chamber or receptacle,
third, causing oxidizing fumes to fill its interior, fourth, causing oxidizing fumes to
flow out of the chamber after the fur has been treated, fifth, opening the chamber
and removing the treated fur.
8. As a new article of manufacture, fur prepared for felting in the manner herein
described.

page_text: 9. As an improvement in the art of treating fur with oxidizing vapors to adapt
it for felting, the process which consists in first preparing the oxidizing fumes or
vapors from proper material or materials, and then causing the fuines or vapors to
flow in a current around in contact with and past the fur to be treated, substantially
as described.
10. As an improvement in the art of treating fur with oxidizing fumes or vapors
to adapt it for felting the process which consists in first preparing the oxidizing
vapors or fumes from proper material or materials, and then in moving or passing
the fur to be treated through the said fumes, substantially as described.
11. As an improvement in the art of treating fur with oxidizing vapors to adapt
it for felting, the process which consists in preparing oxidizing fumes or vapors
from proper material or materials, and in mixing the said vapors with the vapor of
water and submitting the fur to the action of the commingled vapors, substantially
as described.
12. As an improvement in the art of treating fur with prepared oxidizing fumes
or vapors to adapt it for felting, the process which consists in first dampening the
fur with water, and then submitting it in the damp condition to the action of
prepared oxidizing fumes or vapors, substantially as described.
Dated this 18th day of February 1886.
EDMUND TWEEDY.
HENRY LEFFERT BREVOORT.
ISAIAH LEWIS ROBERTS.
Carpmael & Co.,
Agents for the Applicants.