IMPROVEMENTS IN MORDANTING OR PREPARING WOVEN OR FELTED FABRICS FOR PRINTING
Year: 1877

page_text: LETTERS PATENT to Henry Dewhurst, of Huddersfield, in the County of York,
Woollen Printer, for the Invention of "IMPROVEMENTS IN MORDANTING OR
PREPARING WOVEN OR FELTED FABRICS FOR PRINTING."
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page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Dewhurst in the Great Seal Patent Office on the 6th
December 1877.
HENRY DEWHURST, of Huddersfield, in the County of York, Woollen Printer.
"IMPROVEMENTS IN MORDANTING OR PREPARING WOVEN OR FELTED FABRICS FOR
PRINTING."
This Invention relates to a new method of preparing fabrics or the raw materials,
whether consisting entirely or partially of wool or of wool mixed with other
fibrous substances for the process of printing, such preparation being commonly
:-In
termed mordanting, and I carry out my Invention in the following manner :-
the case of woven or felted fabrics in the piece I pass or run the pieces by means
of machinery through a closed chamber, made of wood or other suitable material,
over rollers placed at the top and bottom of the chamber in sufficient number to
expose the piece sufficiently long to the combined action of chlorine gas and moist
air. For flannels and light woollen and stuff goods I find that an exposure of two
minutes is sufficient, but for heavy woollen goods a somewhat longer exposure is
required.
I
I find that the most convenient method of producing the chlorine gas for use in
the aforesaid closed chamber is as follows:-I put into a pit or cistern, placed below
or near the chamber and freely opening into it, about 50 gallons of water and
6 gallons of a solution of chloride of lime or bleaching powder, standing at 9° T.,
and I warm up the mixture by means of a steam pipe to a temperature of 140° F.,
or thereabouts, and I keep it at or near that temperature during the process.
liberate or discharge chlorine gas from the aforesaid mixture of water and solution
of chloride of lime by adding sulphuric acid to it. When commencing work with
light goods I add about one quart of sulphuric acid of 80° T., and after every two
pieces of about fifty yards in length have passed through the chamber, I add an
additional half pint of sulphuric acid and one pint of solution of chloride of lime
of the aforesaid strengths, in order to keep up a uniform supply of chlorine gas in
the chamber. At the aforesaid temperature of 140° F. a sufficient quantity of
steam rises from the pit or cistern aforesaid to keep the atmosphere within the
chamber in a suitably moist state.
I do not confine myself to the aforesaid mode of producing or generating chlorine,
gas, as I find that it is equally applicable when generated by other well-known'
processes.
In the case of short lengths of woven or felted fabric, shaped or intended to be
shaped for a garment of any kind, I expose the said short lengths to the combined
action of moist air and chlorine gas by suspending them in a closed chamber,
and generating the chlorine gas in or near the said chamber by the process herein-
before described; the chlorine gas entering the chamber, as also herein-before
described, the time of exposure in the chamber varying with the thickness of the
material.
In the case of wool or other raw or unwoven material, I expose the same to the
combined action of moist air and chlorine gas by passing the said wool or raw
material backwards and forwards through a closed chamber in a manner similar to
that by which wool is dried in a wool-drying machine. I generate the chlorine
and moist air and convey the same into the chamber or machine, in the manner
herein-before described for woven or felted fabrics in the piece. I find that wool
or raw material requires to be exposed in the said chamber or machine to the
combined action of noist air and chlorine gas for two minutes, or thereabouts, from
the time of entering to that of leaving the machine.
I claim as my Invention, the use of chlorine gas and moist air for preparing or

page_text: mordanting woven or felted fabrics or the raw material of which they are composed,
substantially as herein described.
In witness whereof, I, the said Henry Dewhurst, have hereunto set my
hand and seal, this Fourth day of December, in the year of our Lord One
thousand eight hundred and seventy-seven.
HENRY DEWHURST. (L.S.)