An Improved Film or Skin.
Year: 1889

page_text: Date of Application. 20th Dec., 1889
Complete Specification Left, 19th Sept., 1890-Accepted, 25th Oct., 1890
PROVISIONAL SPECIFICATION.
An Improved Film or Skin.
I JAMES WILLIAMS, of Willesden Paper Works, Willesden Junction in the County
of Middlesex Chemist, do hereby declare the nature of this invention to be as
follows:-
The object of this invention is the production of a structureless film or skin possessing
the lightness, flexibility and other properties of fine paper with the additional advan-
tages of increased transparency, and of resisting the action of water, steam, weak acids,
alkalies and most solvents.
To produce this film, I float paper on a solution of a solvent of cellulose, preferably
cuprammonium hydroxide, by which.one surface of the paper is partially dissolved,
and converted into a layer of cellulose solution or jelly-like cupro-cellulose.
I then convey the paper over drums (the untreated dry surface resting on the drums).
round a hot cylinder where the layer of cellulose loses its glutinous condition and
becomes a kind of glaze or skin, owing to the expulsion of ammonia and water. It is
then passed between felt round other cylinders until the requisite dryness of the film
has been secured.
In this stage the product (when cuprammonia is used) consists essentially of a film
or skin of cellulose combined with hydrate of copper and supported at the back by a
sheet of paper.
To isolate the film or skin, the supporting surface is treated with hot or boiling
water, which readily disintegrates the paper and reduces it to a pulpy condition, and
to effect separation of the pulp from the film J agitate with water, pass under a stream
of water, or pass the film over revolving brushes or rollers until free from the disinte-
grated paper. The paper debris is recovered from the washing waters by a suitable
save-all, for re-manufacture into paper and the film is dried by passing round warm
cylinders.
The film thus obtained is green but where it is required to have a colourless film, the
supported skin or film is treated with warm dilute sulphuric or other convenient acid
which (preferably simultaneously with the disintegration of the paper surface) dissolves
out the copper hydrate, and after being subject to agitation or attrition by any of the
methods mentioned above, and being well washed in water, a colourless film of nearly
pure cellulose is obtained which is dried by passing round warm cylinders.
A similar process mutatis mutandis is followed when other solvents are used.
The colourless film or skin may be treated with an antiseptic to render it valuable
for surgical and other purposes.
Dated this 19th day of December 1889.
COMPLETE SPECIFICATION.
An Improved Film or Skin.
JAMES WILLIAMS, of Willesden Paper Works, Willesden Junction, in the County
of Middlesex, Chemist 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 :-
The object of this invention is the production of a structureless film or skin possessing
the lightness flexibility and other properties of fine paper with the additional advantages
of increased transparency, and of resisting the action of water, steam, weak acids,
alkalies and most solvents.
To produce this film, I float paper on a solution of a solvent of cellulose, preferably

page_text: cuprammonium hydroxide, by which one surface of the paper is partially dissolved,
and converted into a layer of cellulose solution or jelly like cupra cellulose. I then
convey the paper over drums (the untreated dry surface resting on the drums) round
a hot cylinder where the layer of cellulose loses its glutinous condition and becomes a
kind of glaze or skin, owing to the expulsion of ammonia and water. It is then
passed between felt round other cylinders until the requisite dryness of the film has
been secured.
In this stage the product (when cupra ammonia is used) consists essentially of a film
or skin of cellulose combined with hydrate of copper and supported at the back by a
sheet of paper. To isolate the film or skin the supporting surface is treated with hot
or boiling water which readily disintegrates the paper and reduces it to a pulpy con-
dition and to effect separation of the pulp from the film I agitate with water pass
under a stream of water, or pass the film over revolving brushes or rollers until free
from the disintegrated paper. The paper debris is recovered from the washing waters
by a suitable save-all, for re-manufacture into paper and the film is dried by passing
round warm cylinders.
The film thus obtained is green but where it is required to have a colourless
film, the supported skin or film is treated with warm dilute sulphuric or other
convenient acid which (preferably simultaneously with the disintegration of the
paper surface) dissolves out the copper hydrate, and after being subject to agitation
or attrition by any of the methods mentioned above, and being well washed in
water a colourless film of nearly pure cellulose is obtained which is dried by passing
round warm cylinders.
A similar process mutatis mutandis is followed when other solvents are used.
The colourless film or skin may be treated with an antieeptic to render it
valuable for surgical and other purposes.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim :
1. The process of forming a structureless film or skin possessing the properties
of fine paper with increased transparency and the capability of resisting the action
of water, steam, weak acid, alkalies or other solvents.
2. The process of forming a practically pure structureless film or skin of cellulose
by floating paper upon the surface of a solvent.
o
3. The process of forming a practically pure structureless film or skin of cellulose
by exposing the surface of paper to the action of cuprammonium hydro-oxide and
subsequently removing the residua! unaffected paper by means of water and the
copper hydrate by means of acid substantially as described.
Dated this 19th day of September 1890.
TAMES WITT TAMO
JAMES
TAMMO WITT TAMO
WITTIAMO
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