Dyeing Machines
Dye-tubs and vats, such as those described above, have been largely
superseded by machines in which the handling or working of the
materials being dyed is effected by mechanical means. There have been
a large number of dyeing machines invented, some of these have not
been found to be very practical, and so they have gone out of use.
Space will not admit of a detailed account of every kind of machine,
but only of those
hich are in constant use in dye-works.
#Dyeing Loose or Raw Wool and Cotton.#--Few machines have been designed
for this purpose, and about the only successful one is
Delahunty's Dyeing Machine.--This is illustrated in figure 12. It
consists of a drum made of lattice work which can revolve inside an
outer wooden casing. The interior of the revolving drum is fitted with
hooks or fingers, whose action is to keep the material open. One
segment of the drum is made to open so that the loose cotton or wool
to be dyed can be inserted. By suitable gearing the drum can be
revolved, and the dye-liquor, which is in the lower half of the wooden
casing, penetrates through the lattice work of the drum, and dyes (p. 044)
the material contained in it. The construction of the machine is well
shown in the drawing, while the mode of working is obvious from it and
the description just given. The machine is very successful, and well
adapted for dyeing loose or raw wool and cotton. The material may be
scoured, bleached, dyed or otherwise treated in this machine.
The Obermaier Machine, presently to be described, may also be used for
dyeing loose cotton or wool.
#Dyeing Slubbing, Sliver or Carded Wool.#--It is found in practice that
the dyeing of loose wool is not altogether satisfactory, the
impurities they naturally contain interfere with the purity of the (p. 045)
shade they will take. Then again the dyes and mordants used in dyeing
them are found to have some action on the wire of the carding engine
through which they are passed; at any rate, a card does not last as
long when working dyed wools as when used on undyed cotton or wool
fibres. Yet for the production of certain fancy yarns for weaving some
special classes of fabrics it is desirable to dye the wool before it
is spun into thread. The best plan is undoubtedly to dye the fibre
after it has been carded and partly spun into what is known as
slubbing, or sliver. All the impurities have been removed, the wool
fibres are laid straight, and so it becomes much easier to dye. On the
other hand, as it is necessary to keep the sliver or slubbing straight
and level, no working about in the dye-liquors can be allowed to take
place, and so such must be dyed in specially constructed machines, and
one of the best of these is the
Obermaier Dyeing Machine, which is illustrated in figure 13.--In (p. 046)
the Obermaier apparatus dye-vat, A, is placed a cage consisting of an
inner perforated metal cylinder, C, and an outer perforated metal
cylinder, D; between these two is placed the material to be dyed. C is
in contact with the suction end of a centrifugal pump, P, the delivery
end of which discharges into the dye-vat A. The working of the machine
is as follows: the slubbing or sliver is placed in the space between C
and D rather tightly, so that it will not move about. Then the inner
cage is placed in the dye-vat as shown. The vat is filled with the
dye-liquor, which can be heated up by a steam pipe. The pump is set in
motion, the dye-liquor is drawn from A to C, and in so doing passes
through the material packed in B and dyes it. The circulation of the
liquor is carried on as long as experience shows to be necessary. The
dye-liquor is run off, hot water is run in to wash the dyed material,
and the pump is kept running for some time to ensure thorough rinsing,
then the water is run off, and by keeping the pump running and air
going through a certain amount of drying can be effected. This machine
works very well, and with a little experience constant results can (p. 047)
be obtained. The slubbing or sliver may be scoured, bleached, rinsed,
dyed, washed, soaped, or otherwise treated without removing it from
the machine, which is a most decided advantage.
#Yarn Dyeing Machines.#--In figure 14 is given an illustration of a
machine for dyeing yarn in the hank form, made by Messrs. Read
Holliday & Sons, of Huddersfield. The illustration gives a very good
idea of the machine. It consists of a wooden dye-vat, which can be
heated by steam pipes in the usual way. Extending over the vat are a
number of reels or bobbins, these are best made of wood or enamelled
iron. These reels are in connection with suitable gearing, so that
they can be revolved. There is also an arrangement by means of which
the reels can be lifted bodily in and out of the dye-vat for the
purpose of taking on and off the hanks of yarn. A reel will hold about
2 lb. of yarn. The working of the machine is simple. The vat is filled
with the requisite dye-liquor. The reels which are lifted out of the
vat are then charged with the yarn, which has been previously wetted
out. They are then set in revolution and dropped into the dye-vat, and
kept there until it is seen that the yarn has acquired the desired
shade. The reels are lifted out and the hanks removed when the machine
is ready for another lot of yarn.
There are several makers of hank-dyeing machines of this type, and as
a rule they work very well. The only source of trouble is a slight
tendency for the yarn on one reel if hung loosely of becoming
entangled with the yarn on other reels. This is to some extent
obviated by hanging in the bottom of the hank a roller, which acts as
a weight and keeps the yarn stretched and so prevents it flying about.
To some makes of these machines a hank wringer is attached.
Klauder-Weldon Hank-dyeing Machine.--This is illustrated in (p. 048)
figure 15, which shows the latest form. It consists of a
half-cylindrical dye-vat built of wood. On a central axis is built two
discs or rod carriers, which can revolve in the dye-vat, the
revolution being given by suitable gearing which is shown at the side
of the machine. On the outer edge of the discs are clips for carrying
rods on which one end of the hanks of yarn is hung, while the other
end is placed on a similar rod carrier near the axle. The revolution
of the discs carries the yarn through the dye-liquor contained in the
lower semi-cylindrical part of the machine previously alluded to. (p. 049)
At a certain point in every revolution of the discs the rods carrying
the yarns are turned a little; this causes the yarn to move on the
rods, and this motion helps to bring about greater evenness of dyeing.
The most modern form of this machine is provided with an arrangement
by means of which the whole batch of yarn can be lifted out of the
dye-liquor. Arrangements are made by which from time to time fresh
quantities of dyes can be added if required to bring up the dyed yarn
to any desired shade. This machine works well and gives good results.
Beyond the necessary labour in charging and discharging, and a little
attention from time to time as the operation proceeds, to see if the
dyeing is coming up to shade, the machine requires little attention.
Many other forms of hank-dyeing machine have been devised. There is
Corron's, in which an ordinary rectangular dye-vat is used. Round this
is a framework which carries a lifting and falling arrangement that
travels to and fro along the vat. The hanks of yarn are hung on rods
of a special construction designed to open them out in a manner as
nearly approaching hand work as is possible. The machine works in this
way. The lifting arrangement is at one end of the vat, the hanks are
hung on the rods and placed in the vat. Then the lifter is set in
motion and moves along the vat; as it does so it lifts up each rod
full of yarn, turns it over, opening out the yarn in so doing, then it
drops it again in the vat. When it has travelled to the end of the vat
it returns, packing up the rods of yarn in so doing, and this motion
is kept up until the dyeing is completed. This machine is very
ingenious.
A type of machine which has been made by several makers consists of an
ordinary rectangular dye-vat surrounded with a framework carrying a
number of sets of endless chains, the links of which carry fingers.
The hanks of yarn are hung on rods at one end of which is a tooth (p. 050)
wheel that when in position fits into a rack on the side of the vat.
The action of the machine is this, the hanks are hung on the rods and
placed at the entrance end of the vat, by the moving of the chains it
is carried along the vat and at the same time revolves, thus turning
over the yarn, which hangs in the dye-liquor; when it reaches the
opposite end of the vat, the rod full of yarn is lifted out, carried
upwards and then towards the other end of the vat when it is again
dropped into the dye-vat to go through the same cycle of movements
which is continued until the yarn is properly dyed.
#Piece Dyeing Machines.#--Wherever it is possible it is far more
preferable to dye textile fabrics in the form of woven pieces rather
than in the yarn from which they are woven. During the process of
weaving it is quite impossible to avoid the material getting dirty and
somewhat greasy, and the operations of scouring necessary to remove
this dirt and grease has an impairing action on the colour if dyed
yarns have been used in weaving it. This is avoided when the pieces
are woven first and dyed afterwards, and this can always be done when
the cloths are dyed in one colour only. Of course when the goods are
fancy goods containing several colours they have to be woven from dyed
yarns.
The most common form of machine in which pieces are dyed is the
jigger, commonly called the jig, this is shown in figure 16. It
consists of a dye-vessel made long, sufficiently so to take the piece
full width, wide at the top, narrow at the bottom. At the top on each
side is placed a large winding roller on which the cloth is wound. At
the bottom of the jig is placed a guide roller round which passes the
cloth. In some makes of jigs there are two guide rollers at the bottom
and one at the top as shown in the illustration, so that the cloth
passes several times through the dye-liquor. In working the cloth is
first wound on one of the rollers then threaded through the guide (p. 051)
rollers and attached to the other winding roller. When this is done
dye-liquor is run into the jig, and the gearing set in motion, and the
cloth wound from the full on to the empty roller. With the object of
keeping the piece tight a heavy press roller is arranged to bear on
the cloth on the full roller. When all the cloth has passed from one
roller to the other it is said to have been given one end. The
direction of motion is now changed and the cloth sent in the opposite
direction through the jig and the piece has now received another
end. This alternation from one roller to the other is continued as
long as is deemed necessary, much depending on the depth of colour
which is being dyed, some pale shades may only take two or three ends,
deeper shades may take more. When dyeing wool with acid colours which
are all absorbed from the dye-liquor, or the bath is exhausted, it is
a good plan to run the pieces several ends so as to ensure thorough
fixation of the dye on the cloth.
It is not advisable in working these jigs to add the whole of the dye
to the liquor at the commencement, but only a part of it, then when
one end is given another portion of the dye may be added, such (p. 052)
portions being always in the form of solution. Adding dyes in powder
form inevitably leads to the production of colour specks on the
finished goods. The reason for thus adding the dye-stuff in portions
is that with some dyes the affinity for the fibre is so great that if
all were added at once it would be absorbed before the cloth had been
given one end, and, further, the cloth would be very deep at the front
end while it would shade off to no colour at the other end. By adding
the dye in portions this difficulty is overcome and more level shades
are obtained, but it is met with in all cases of jigger dyeing. It is
most common in dyeing wool with basic dyes like Magenta, Auramine, (p. 053)
Methyl Violet or Brilliant Green, and with acid dyes like Acid Green,
Formyl Violets, Azo Scarlet or Acid Yellow.
Some attempts have been made to make jiggers automatic in their
reversing action, but they have not been successful owing to the
greatly varying conditions of length of pieces, their thickness, etc.,
which have to be dyed, and it is next to impossible to make all
allowances for such varying conditions.
In figure 17 is shown the jig in section, when the working of the
machine can be more easily traced.
#The Jig Wince or Wince Dye Beck.#--This dyeing machine is very largely
used, particularly in the dyeing of woollen cloths. It is made by many
makers, and varies somewhat in form accordingly. Figures 18 to 21 show
three forms by different makers. In any make the jig wince or wince
dye beck consists of a large rectangular, or in some cases (p. 054)
semi-cylindrical, dye-vat. Probably the best shape would be to have a
vat with one straight side at the front, and one curved side at the
back.
In some a small guide roller is fitted at the bottom, under which the
pieces to be dyed pass. Steam pipes are provided for heating the
dye-liquors. The beck should be fitted with a false bottom, made of
wood, perforated with holes, or of wooden lattice work, and under
which the steam pipes are placed. The object being to prevent the
pieces from coming in contact with the steam pipes, and so (p. 055)
preventing the production of stains. Above the dye-vat and towards the
back is the wince, a revolving skeleton wheel, which draws the pieces
out of the dye-vat at the front, and delivers them into it again at
the back. The construction of this wince is well shown in the
drawings. The wince will take the pieces full breadth, but often they
are somewhat folded, and so several pieces, four, five or six, can be
dealt with at one time. In this case a guide rail is provided in the
front part of the machine. In this rail are pegs which serve to keep
the pieces of cloth separate, and so prevent entanglements. The pieces
are stitched end to end so as to form an endless band. When running
through the vat they fall down in folds at the back part of the beck,
and are drawn out from the bottom and up in the front. Each part thus
remains for some time in the dye-liquor, during which it necessarily
takes up the dye.
Figures 18 and 19 show forms of these wince dyeing machines,
constructed of wood, and very largely used in the dyeing of woollen
cloths. They are serviceable forms, and give very good results, being
suitable for all dyes.
Figure 20 is a form of machine better adapted than the preceding (p. 056)
for the dyeing of plush fabrics. In this kind of cloth it is important
that the pile should not be interfered with in any way, and experience
has shown that the winces of the form shown in figures 18 and 19 are
rather apt to spoil the pile; further, of course, plush fabrics are
dyed full breadth or open. In the wince now shown all troubles are (p. 057)
avoided, and plush fabrics can be satisfactorily dyed in them.
Figure 21 shows a dye-bath built of iron, cased with copper, suitable
for dyeing most colours on woollen cloths.
In the jig and wince dyeing machines the pieces necessarily are for a
part of the time, longer in the case of the jigger than in that of the
wince, out of the dye-liquor and exposed to the air. In the case of
some dyes, indigo especially, this is not desirable, and yet it is
advisable to run the cloth open for some time in the liquor so as to
get thoroughly impregnated with the dye-liquor.
The so-called hawking machine, figure 22, is an illustration of Read
Holliday's hawking machine, made by Messrs. Read Holliday & Sons, of
Huddersfield. There is the dye-vat as usual; in this is suspended the
drawing mechanism, whose construction is well shown in the drawing.
This is a pair of rollers driven by suitable gearing, between which
the cloth passes, and by which it is drawn through the machine. A
small roller ensures the cloth properly leaving the large rollers, (p. 058)
then there is a lattice-work arrangement over the pieces are drawn. In
actual work the whole of this arrangement is below the surface of the
dye-liquor in the vat. The piece to be dyed is threaded through the
machine the ends stitched together, then the arrangement is lowered
into the dye-vat and set in motion, whereby the cloth is drawn
continuously in the open form through the dye-liquor, this being done
as long as experience shows to be necessary. This hawking machine will
be found useful in dyeing indigo on wool, in mordanting and dyeing
wool with the Alizarine series of dyes.