Improvements in or relating to Mercerising Vegetable Fibrous Substances and in the Manufacture of Fabrics.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c. Act, 1883), as required
by the decision of the Chief Examiner of the 5th day of August, 1898.
Date of Application, 18th Sept., 1896-Accepted, 4th Sept., 1897
COMPLETE SPECIFICATION (AMENDED).
Improvements in or relating to Mercerising Vegetable Fibrous
Substances and in the Manufacture of Fabrics.
We, RICHARD THOMAS and EMMANUEL PREVOST, both of 5A, Dahler Dick,
Crefeld, Germany, Dyers, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
Vegetable fibres when mercerised in a strongly stretched condition and washed
whilst maintaining this condition we find acquire a greater strength than the raw
fibre and also acquire a magnificent silky gloss.
The vegetable fibre is subjected in the hank or in the woven fabric in the
stretched state to the action of strong lyes or acids and after the reaction has been
produced (which can be perceived from the parchment-like appearance) is washed
whilst the tension of the stretching is maintained until the internal stresses
existing in the fibre have ceased.
On now removing the fabric or yarn from the stretching apparatus it can be
subjected to further treatment without having to fear shrinking of the same.
Instead of employing a special stretching device the fibre may also be subjected
to the action of strong alkaline lye or acid whilst wound on cops, reels, bobbins,
or the like where the thread is in tension. It is advisable to employ apparatus
that are specially suited for this purpose in order to facilitate the penetration of
the treating liquid and of the water in washing.
If the loose or stretched fibre be stretched during the mercerising process
beyond its original dimensions it can be washed without being in tension and
without shrinking to such an extent as it does when mercerised without tension.
This modification is specially suitable for very loosely twisted fibrous materials
which after the action of the mercerising liquid and after the removal of the
excess liquid are stretched beyond their dimensions when in the raw state and
can then be washed without tension.
In the present invention therefore the vegetable fibre is stretched for longer
or shorter period during the mercerising process that is to say during the period
from the wetting of the fibre with the alkalies or acids up to the removal of the
latter from the fibre. It is immaterial whether this tension existed already
before the commencement of the mercerising process whereby shrinking of the
fibre is prevented altogether or whether the tension is applied only after the fibre
has been wetted with the mercerising liquid but before it is washed that is to say
the fibre that has shrunk at first is stretched out again. It is further immaterial
in what manner the condition of the fibre produced by the tension during the
mercerising process is fixed whether it be by maintaining the tension up to the
removal of the mercerising liquid or according to the present modification by a

page_text: previous stretching to the original dimensions and beyond so that when the fibre
is subsequently washed in the loose state it possesses a certain margin to allow
for shrinking and this shrinking is wholly or partly compensated or made up by
the previous correspondingly great amount of stretching.
A further modification is based on the following observations:-
On treating vegetable fibrous substances with a caustic lye of about 10
to 20° Bé. no mercerising action takes place at ordinary temperature. But a
mercerising action can be easily produced by subjecting the said fibrous sub-
stances in a stretched state to a temperature of less than 0° C. whilst they are
still wet with the lye.
This shows the way to use dilute mercerising liquids in the present process by
subjecting the fibre-moistened with the liquid in the stretched state to a
⚫temperature of about 0° C. and below.
The fibre can be either first wetted with the lye and then cooled or it may be
treated at once with the cold lye.
The tension can be imparted to the fibre prior to the cooling or wetting or it
may be imparted to the fibre in the cold only after the shrinking of the wetted
fibre. The fixing of the condition produced in the stretched fibre by the cold lye
may be effected by maintaining the tension up to the-heating of the fibre to
ordinary temperature (say about + 15° C.) or up to the washing out of the lye
or it may be effected as above described by stretching the wet fibre in the cold
beyond its original dimensions and heating or washing the same in its loose state
in which case the fibre then shrinks again to some extent.
In the case of very tightly twisted yarns or of fabrics of great density or close-
ness the washing out of the lye in the stretched state of the material is attended
with difficulty because the lye that has penetrated into the fibre adheres very
strongly to the stretched yarn or fabric and the washing water flows away over
the surface of the stretched fibrous materials without washing out the lyes con-
tained therein.
This drawback is obviated according to the present invention by employing
instead of pure water dilute acids (or dilute alkalies when the mercerising has
been done with acids) and thus effecting in this way by chemical neutralisation
the removal of the lye from the interior of the fibre. Another improvement
consists in weaving together fibre that has been mercerised with fibre that has
not been mercerised and dyeing the fabric thus produced.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same to be performed we declare that what
wo claim is:--
1. The process herein specified according to which the fibrous substances (woven)
or unwoven) treated with lyes or acids are stretched beyond their original
dimensions and thereafter are washed in the loose unstretched state for the pur-
pose of producing a silky lustre substantially as and for the purposes described.
2. The process herein specified according to which the vegetable fibre
(in the hank or in the woven fabric) prepared without tension is stretched
up to and beyond its original dimensions whilst it is still wet with the lye and
is then washed in the loose unstretched state for the purpose of producing a silky
lustre substantially as and for the purposes herein before described.
3. The process herein specified consisting in that loosely twisted fibrous
materials are stretched beyond their dimensions in the raw state after subjection
to the action of the alkalies or acids and removal of the excess of the same and
are washed after the stretching or tension has ceased for the purpose of producing
a silky lustre substantially as and for the purposes herein before described.
4. Process for the manufacture of fabrics with designs by weaving together
fibre that has been mercerised while stretched with fibre that has not been mer-
cerised and dyeing the mixed fabric substantially as and for the purposes herein-
before described.

page_text: 5. The modified process herein specified for mercerising vegetable fibre accord-
ing to which the stretched fibre is subjected in the cold to the action of the
mercerising liquid for the purpose of enabling dilute lyes to be utilised for mer-
cerising substantially as and for the purposes herein before described.
6. The modified process herein specified for mercerising vegetable fibrous sub-
stances according to which the washing out of the mercerising liquid is partly
or wholly superseded by neutralising the same substantially as and for the pur-
poses hereinbefore described.
Dated this 18th day of September 1896
TONGUE & BIRKBECK,
Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.