IMPROVEMENT IN ADHESIVE PLASTERS, AND IN THE MEANS, MODES, AND PROCESSES FOR MANUFACTURING THE SAME
Year: 1876

page_text: LETTERS PATENT to Thaddeus Hyatt, of GG, Gloucester Gardens, Hyde Park,
London, County of Middlesex, Inventor, for the Invention of "IMPROVEMENT
IN ADHESIVE PLASTERS, AND IN THE MEANS, MODES, AND PROCESSES FOR
MANUFACTURING THE SAME."
Sealed the 11th May 1877, and dated the 8th December 1876.
PROVISIONAL SPECIFICATION left by the said Thaddeus Hyatt at the Office
of the Commissioners of Patents on the Sth December 1876.
"
THADDEUS HYATT, of 66, Gloucester Gardens, Hyde Park, London, County of
Middlesex, Inventor. IMPROVEMENTS IN ADHESIVE PLASTERS, AND IN THE MEANS,
MODES, AND PROCESSES FOR MANUFACTURING THE SAME."
The adhesive plasters in common use are stiff, unyielding, and uncomfortable to
wear, with the exception of those called "porous plasters" or plasters pierced with
a number of small holes for the exit of perspiration And my Invention is in the
nature of an improvement upon this kind or description of plaster, that is to say,
upon the plasters designed to allow perspiration to pass off freely.
The adhesive plaster in common use known under the name of "porous plaster" is
pierced with holes one-eighth of an inch in diameter; about twelve such holes
being made in every square inch, so that they are a quarter of an inch apart in one
direction, and three-eighths of an inch apart in another, the consequence of which
is that although the plaster is perforated it is not "porous in the sense of
ventilating or having the function to carry off perspiration; the plaster is also
objectionable from its extreme stickiness, which sometimes soils and injures the
clothing of the wearer of it. This stickiness is due to the nature of the composition,
which is made so to make the plaster flexible.
My improvement upon this plaster, according to one part of my Invention,
consists in making a truly porous plaster by making it capable of actually letting
out perspiration, which can be done only by multiplying the perforations as far

page_text: as possible in imitation of the skin itself. I find, for example, that it is possible
to make between two and three hundred holes to the square inch of plaster instead
of the twelve holes to the inch of the common porous plaster. In doing this I find
it important to employ a composition of sufficient density to allow the punching
instruments to work through it freely, that is to say, I make it for common plasters
of resin combined with only enough Burgundy pitch to toughen it. A part of my
Invention for some plasters consisting in the use and application of sheet india-
rubber, gutta percha, or equivalent elastic and flexible material, as a backing to
spread the melted or glutinous composition on.
A part of my Invention also consists in treating certain kinds of adhesive plasters
by heat to toughen the material and prevent sticking; for example, I find that
a plaster spread with the adhesive compound of the pharmacopeia, known under
the heading of "resin plaster," and composed of "resin 4 oz., lead plaster 2 lbs.,
hard soap 2 oz.," melted and stirred together by gentle heat, is very sticky when
left in its natural state; but by exposing the spread plaster to the fire for a short
time, say, for one or two minutes, it becomes tough and clean to handle, and inay
be pierced with holes by the ordinary machinery used for making "perforated
Bristol board" (an article well known in commerce), the plaster nevertheless
retaining its necessary quality of adhesiveness for application to the skin.
L
I also find that by dipping calico or paper into a bath of adhesive compound
brought to a sufficiently fluid state by heat, and then draining it before the fire
or in a heated chamber, I am able to use paper or very open calico, or material of
flimsy texture, as this method strengthens such foundation materially.
According to another part of my Invention, to make the plaster more pliable and
convenient for use, instead of spreading out the pitch or adhesive material in an
unbroken or continuous surface upon the foundation, I form it in the shape or con-
dition of specs, spots, dots, or lines, so that the only part of the surface that is
continuous is the space between the specs, spots, dots, or lines, and this gives the
plaster or sheet its flexibility.
In carrying this part of my Invention into effect, according to one part of my
Invention my improvement consists in stamping or otherwise forming the surface,
whether calico, paper, or other foundation, into two levels, the specs, spots, dots,
or lines forming the top level or face for the pitch or plaster surface, and the bottom
level being the continuous or ventilating space, the same being effected by using
a crimped or corrugated material, the crimps or corrugations running in one
direction only to produce a lined surface, but running crosswise to produce a surface
of dots, specs, or spots.
In other cases where I perforate the paper I sometimes strengthen it by an open-
work calico backing, to which it is cemented.
When made in small sizes or single plasters the work may be done by hand, but
when manufactured in rolls or by wholesale they may be made by machinery sub-
stantially the same as is now used for the manufacture of the common or "poor
man's plaster;" the modification or method required to spread the adhesive material
according to my plan, where the surface is one level, being a stencil plate or sheet,
which may be either metal, paper, or other substance.
When the plaster is spread by hand the stencil plate laid upon the muslin or
foundation, and the pitch, gum, or adhesive material having been previously melted
or heated to the right degree is then so spread over the stencil as to fill the
openings of the same; the stencil being then lifted, the specs, spots, dots, or lines of
adhesive material are left adhering to the muslin or foundation.
Where the stencil plate is made of paper it may be gummed to the cloth or
foundation, the same having been previously starched or otherwise stiffened or
glazed; the paper stencil is afterwards removed by being wet or dampened.
In making the plasters by machinery the composition is kept fluid in a heated
trough and fed upon the sheet as it passes between the feed rollers, a flexible or
plastic stencil plate in sheet or band form overlaying the calico or paper backing

page_text: and moving between the rollers with it according to the well known machine process
in common use.
According to another part of my Invention I make a flexible plaster by first
applying the adhesive material to india-rubber or other threads, tapes, cords, or
ribbons, or to paper strips, and then cement the same to a backing of thin sheet
india-rubber, Victoria muslin, or other suitable material, arranging the threads or
tapes either in parallel or cross bar lines, so as to leave open ventilation spaces
between them. Or the prepared threads may be first woven in a loom into a sort
of net or openwork, and then cemented to the backing.
A part of the Invention consists in the use of a calico or equivalent foundation
made of exceeding loose or open texture to allow perspiration readily to pass
through without piercing it with special holes for the purpose. This sort of
material is of preference first starched or otherwise glazed, and then the adhesive
web or netting is cemented to it; after which the glaze or starch is washed out to
make it porous, that is to say, when the plaster facing is cemented to the backing
by a cement that melts by heat; but when a cement like glue or gun arabic is
employed, then the backing is of proference not glazed or starched.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thaddeus Hyatt in the Great Seal Patent Office on the 17th May
1877.
THADDEUS HYATT, of 66, Gloucester Gardens, Hyde Park, London, in the
County of Middlesex, Inventor. "IMPROVEMENTS IN ADHESIVE PLASTERS, AND IN
THE MEANS, MODES, AND PROCESSES FOR MANUFACTURING THE SAME."
**
My Invention relates to improvements in adhesive plasters (whether made upon
a foundation or backing of paper, cloth, leather, or other material) with reference
to making them flexible so as to be in a measure self-conforming to the person of
the user, and consequently comfortable to wear, the means employed to produce this
result also causing the plaster to be ventilating. The common
porous plaster "
owes its flexibility to the nature of the composition employed (india-rubber being
one of the ingredients used), and not to the perforations of the plaster, neither do
such perforations make the plaster ventilating to any appreciable. degree, there being.
but about twelve perforations to each square inch of plaster.
The means employed by me to secure the object in view are as follows, viz.,
according to one method I make adhesive plasters flexible by the number of per-
forations made to each square inch of plaster, two hundred and fifty-six to the inch
being made in some cases.
According to another method I make the plaster flexible by putting the adhesive
compound on to the backing in the form of specs, spots, dots, or lines, in place of
the continuous surface method of the common plasters.
"
I am aware that blister plaster" has been applied in the form of detached
masses or spots put upon a sticking surface of gummed muslin or calico, but the
blister material is not necessarily the adhesive part of such plaster, the adhesive
surface being a continuous surface like any sticking plaster, and equally as stiff' and
unyielding.
By another method I put the adhesive material upon threads, tapes, or strips of
calico or other material, and afterwards weave the same into a web or open network
which I then stick to a foundation or backing of sheet india-rubber, or to a porous
or loosely woven calico or muslin.
By another method. I crimp or corrugate the foundation or backing, and thus
break up its otherwise continuous surface, the adhesive material being spread upon
the ridges, protuberances, or points of such crimped or corrugated materials; such

page_text: crimped or corrugated material in some cases being thin india-rubber, which being
not only pliable but elastic yields readily to the movements of the body, and is
therefore a comfortable plaster for wear, besides being ventilating. I also use flat
sheet india-rubber as the backing or foundation for my flexible plasters, the adhesive
compound or material being put upon the same in the form of specs, spots, dots, or
lines which likewise tend to make ventilating spaces especially when such rubber
is also perforated between the dots. These flexible and ventilating plasters may be
made as to their medicinal surfaces according to any of the prescribed formulas of
the pharmacopoeia, and may be spread by hand in the usual way of making hand-
spread plasters, or they may be spread by means of machinery in the usual way of
making machine-spread plasters, my Invention not consisting in the medicinal
nature of the adhesive material of the plaster, nor in the modes of spreading the
same.
薯
In making adhesive plasters flexible by perforating the same with a sufficient
number of holes to produce flexibility, it happens in some cases that the process
weakens the material, as in the case of " poor man's plaster," where the adhesive
material is spread upon a paper foundation or backing; a part of my Invention in
such cases consists therefore in the use of paper which has a calico back, such paper
being prepared by gumming or otherwise sticking the two surfaces together; or the
paper is put upon the calico in the form of pulp when the paper is made. This
paper I first coat with the adhesive material and then submit to a punching machine
like that used for manufacturing "perforated zinc" and "perforated Bristol board,"
a convenient size of sheet for punching being that termed "medium."
.
To prevent the composition from scaling off during the operation of punching, it
may be modified in various ways known to the makers of such resinous compounds,
or advantage may be taken of the ordinary material to perforate it while fresh and
not brittle; or the work may be performed in a room where the temperature is
high enough to give flexibility to the composition; or the perforating machine
itself may be provided with an extra bearing plate to lie upon the sheet and cover
it, the punching needles working through the covering plate, such plate of preference
being also faced on its under side with some soft yielding substance, like buckskin
or calico, to equalize the pressure upon the face of the composition and thus prevent
its scaling off.
According to one part of my Invention, in order to facilitate the perforation of
the adhesive composition when of the kind termed "resin plaster" or a composition
of similar character as to being affected by heat, iny improvement consists in exposing
the newly spread plaster to the heat of a fire for a few moments, or making the
plaster by dipping the backing or foundation into a melted or liquid composition
and draining it before a fire; this process serving to strengthen the foundation
particularly when made of paper.
To make the plasters with specs, spots, dots, or lines, I employ a stencil plate
preferably made of thin steel, the leather or other backing being laid upon the usual
rest or bed and brought up to its position in the spreading table by the action of
the treadle moved by the foot of the operator; the stencil plate is then laid upon
the face of the backing, and the melted compound is drawn over it by the spreading
tool which also cuts away and removes all the surplus, when the plaster drops with
the downward movement of the operator in letting down the treadle.
According to another part of my Invention I make a flexible plaster by first
applying the adhesive material to india-rubber or other threads, tapes, cords, or
ribbons, or to paper strips, and then cement the same to a backing of thin sheet
india-rubber, Victoria muslin, or other suitable material, arranging the threads or
tapes either in parallel or cross bar lines so as to leave open ventilation spaces
between them. Or the prepared threads may be first woven in a loom into a
sort of net or open work and then cemented to the backing.
A part of the Invention consists in the use of a calico or equivalent foundation
made of exceedingly loose or open texture to allow perspiration readily to pass

page_text: through without piercing it with special holes for the purpose. This sort of material
is of preference first starched or otherwise glazed, and then the adhesive web or
netting is cemented to it, after which the glaze or starch is washed out to make it
porous, that is to say, when the plaster facing is cemented to the backing by a
cement that melts by heat; but when a cement like glue or gum arabic is employed
then the backing is of preference not glazed or starched.
ICתתימח
TTVATT
201
THADDEUS HYATT.
(L.S.)