Improved Process for Removing Pitch, Tar, and other Coloured Impurities from Finished or Partially Finished Fabrics.
Year: 1895

page_text: Date of Application, 15th Jan., 1895-Accepted, 9th Mar., 1895
COMPLETE SPECIFICATION.
Improved Process for Removing Pitch, Tar, and other Coloured
Impurities from Finished or Partially Finished Fabrics.
We, KARL HEROLD, Linen and Woollen Manufacturer, of 20 Bastergasse,
EDWARD BALATSCH Spinner, of 3 Stefansgasse, and ALEXANDER BAYER,
Chemist, of 65 Thalgasse, all in Brünn, in the Empire of Austria, 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 cleaning of finished or partially finished woollen or hair fabrics from pitch tar
or other colouring matters or impurities has not hitherto been effected by chemical
means, but by the use of mechanically operated burling irons. By the latter means
it is not possible to remove the smaller impurities, and consequently the fabrics so
treated could only be used in dark shades of colouring, whilst they were liable to
injury in the burling operation.
Under the present invention the finished or partially made or finished woollen or
hair fabrics to be cleaned are, either before or during the operation of pulling,
felting or finishing, placed in a cold or heated liquid emulsion of heavy or light tar
oils, prepared with soap, soap-worts, alkalies, acids, etc. and left lying therein for a
longer or shorter time. The oils most suited for this purpose are the hydrocarbons
having their boiling point over 100° C. which are contained in coal tar and tar
yielded by the distillation of peat, wood or shale, though petroleum hydrocarbons
having a high boiling point and the so-called blue and green oils are also adapted
for the purpose. By light tar oil or raw benzol is understood tar oil having a
specific gravity from 0-91 to 0.95. By fractional distillation another tar oil is
produced whose boiling point is under 100° C.
The choice of soap, soap-worts, alkalies, acids, etc. in forming the emulsion will
be dependent on which of these is used in the fulling, felting and dressing or finishing
of the material to be cleaned.
The use of a warm emulsion facilitates the softening of the pitch tar or colouring
matter forming the impurities.
The time during which the fabrics have to lie in the emulsion depends on whether
the impurities occur in larger or smaller clusters, and accordingly require a longer
or shorter time for softening. Thereafter the fabrics so prepared are subjected to
the operations of fulling, felting or finishing, or other manipulations are proceeded
with according to the state of manufacture at which the steeping takes place. By
the treatment above described the impure pitchy parts or colouring matters
consisting of tarry parts or colouring matters mixed with sand, dust, moisture, etc.
adhering to the fabrics in question are dissolved out and separated from the fabrics,
the insoluble ingredients dropping away in the fulling, felting or finishing process
and being left behind so that the fabrics are completely cleaned.
The proportions of the ingredients of the emulsion may vary considerably, but in
general it may consist of one kilo. of soap to twenty kilos. of water to which is
added a quantity of tar oil varying from a hundred grammes, as the minimum, to
one kilo. tar oil as the maximum, to each kilo. of soap, according to the degree of
impurity in the fabric.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
:-
1. The employment of tar oils in emulsion with the usual fluids used in fulling,

page_text: felting and dressing or finishing woollen or hair fabrics as means for freeing such
fabrics from pitch tar or other colouring matters or impurities adhering to them.
2. The process hereinbefore described for effecting the chemical cleaning of
finished or partially finished fabrics.
Dated this 14th day of January 1895.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
St. Vincent Street, Glasgow, Agent for the Applicants.