Title of Invention

DYEING MACHINE WITH AUTOMATIC IN-LINE DIP DEPLETION CONTROL

Abstract A dyeing machine comprises a container (11) in which products to be dyed are placed, a source (12) of coloring liquids adding liquids on command into the container to realize a dye dip, and a unit (13) to circulate the dye dip with respect to the product. During the dyeing process a sampling and analysis device (14) automatically takes samples of liquid from the container at intervals and performs a spectroscopic analysis thereon. An electronic control and calculation device (15) receives the spectroscopic analysis data and calculates therefrom the concentrations of the various dyestuffs in the dip. The behavior thus obtained of the dip can be memorized for future use and/or can be used to command appropriate corrective parameters of the dyeing process.
Full Text "DYEING MACHINE WITH AUTOMATIC IN-LINE DIP DEPLETION
CONTROL"
The present invention relates to a dyeing machine capable
of automatically recording dye concentrations in the dye
dip during the process, testing their trend over time and
if necessary changing it by acting on appropriately chosen
control parameters, for example temperature, pH and so on.
The machine is designed in particular but not exclusively
for textile products.
In the prior art of dying machines the importance of the
so-called 'formula', that is to say the composition of the
dye dip, to achieve optimal results is well known.
Usually, dye dips are made from a composition of several
dyestuffs and if necessary additives in solution or aqueous
dispersion or with solvents. During the dyeing process the
various dyestuffs are often absorbed at different speeds by
the product being dyed. When one of the dyestuffs is no
longer present in the dip in sufficient quantity the dip is
depleted. It is therefore important to known the evolution
of the dip during the process to be able to optimize the
dip formula and to ensure good execution of the process.
In the known art, a series of samplings of the dye liquid
are usually made at intervals during a process and the
samples are analyzed in a laboratory to go back to the
dynamics of the concentrations of the various dyes during
the process. Since this operation is costly in terms of
time and money, it is generally performed only for one or a
few initial sample processes in order to optimize the dip
formula and the application methodology for subsequent in-
line processing. During normal in-line dyeing processes dip
analysis is no longer performed or is performed rarely
while trusting that the dip will always hold the same
behavior found at the beginning.
Unfortunately, the course of the dyestuff concentrations
depends in reality on various parameters such as
temperature, pH, salinity, auxiliary product quantities,
circulation pump speed et cetera.
It has been proposed to monitor the behavior of the colors
in the dye dip by using colored filters chosen to have a
decomposition of the dip in three basic colors. But this
solution proved to be very rough and unsuited to in-line
use.
The international application WO 99/66117 discloses a
portable monitoring system which can be connected to an
existing dyeing machine whenever monitoring of the dye dip
becomes necessary. This device must be inserted along the
circulation loop of the dyeing machine and the spectroscopic
analysis of the dye dip takes place continuously on the
liquid flowing along the circulation loop as long as the
system is arranged therein.
The general purpose of the present invention is to remedy
the above mentioned shortcomings by making available a
dyeing machine which would perform measurement of the
dyestuff concentrations in the dip during normal processing
and take the necessary corrective measures as required.
In view of this purpose it was sought to provide in
accordance with the present invention a dyeing machine
comprising a container in which products to be dyed are
placed, a source of coloring liquids adding liquids on
command into the container to realize a dye dip, a unit to
circulate the dye dip with respect to the product,
spectroscopic analysis means to perform a spectroscopic
analysis on the liquids and an electronic control and
calculation device receiving the spectroscopic analysis
data and calculating therefrom the concentrations of the
various dyes in the dip on the basis of previously
memorized spectroscopic information for the individual
dyes, characterized in that the spectroscopic analysis
means comprise a sampling and analysis device, which during
the dyeing process automatically takes liquid samples from
the container to a reading cell, at intervals, and performs
a spectroscopic analysis on the taken samples in the
reading cell.
To clarify the explanation of the innovative principles of
the present invention and its advantages compared with the
prior art there is described below with the aid of the
annexed drawings a possible embodiment thereof by way of
non-limiting example applying said principles. In the
drawings:
FIG 1 shows a diagrammatic view of a machine in accordance
with the present invention, and
FIG 2 shows a diagrammatic view of a detail of the machine
of FIG 1.
With reference to the figures, FIG 1 shows a textile
products dyeing machine designated as a whole by reference
number 10 and comprising a container 11 pressurized or not
in which are placed the products to be dyed in the form of
yarn, loose textile fiber, mouse ribbon or tow or bolts of
cloth wound or not on cones or supports depending on the
requirements of the prior art. A known liquid dyestuffs
source 12 inputs on command into the container the liquids
to prepare a desired dye dip which is held in circulation
with respect to the product by means of a purposeful
circulation unit 13, for example a pump or a product
handling system.
A sampling and analysis device 14 is connected to the
container to take samples of the liquid in the container at
intervals and perform a spectroscopic analysis thereon. The
analysis device 14 sends the analysis data to an electronic
control and calculation device, for example an
appropriately programmed personal computer which after
receiving the spectroscopic analysis data calculates
therefrom the concentrations of the various dyestuffs in
the dip on the basis of previously memorized spectroscopic
information on the individual dyestuffs. This information
may have been supplied or purchased separately.
The device 14 can be limited to memorizing in a memory 16
the data on the evolution of the dip concentrations for
future use or can even compare the concentrations with the
depletion behavior of the dip preset for reference and take
action on parameters of the process through appropriate
known actuators 34 (heaters, pH correctors) and by varying
the dip circulation speed so as to control the absorption
of the various dyestuffs by the product. For example, by
reducing dip temperature, dyestuff absorption can be
slowed. Corrections of the dyeing process behavior can be
performed automatically this way.
To expand the information on the evolution of the process
the machine can also comprise known sensors 17 for
detection of various preselected physical magnitudes of the
dip.
The device 15 can correlate the measurements of the sensors
17 with the dyestuff concentrations calculated starting
from the spectroscopic analysis and memorize the
correlations for future analysis and optimization of the
process. For example, it might be sensed that a dyestuff is
not absorbed well when the dip temperature exceeds a
certain value and this could serve to optimize the behavior
of temperatures in the future. The physical magnitudes
detected by the sensors can advantageously comprise the
temperature and pH of the dip, the speed of the
recirculating pump, salinity et cetera. Correlations can
also be established between the behavior of the
concentrations and the addition of additives - for example,
salts - so as to optimize the times of addition of these
additives to the dip.
It is also very important to be able to appreciate the
different profiles of depletion of the specific dyestuffs
in the dye dip with variation in the surrounding parameters
and the dyestuffs.
The sensors can also act as feedback for accurate control
of the actuators 34.
The spectroscopic analysis device comprises a reading cell
18, a suction device 19 which fills the cell with the
liquid taken from the container 11, and a spectrophotometer
20. Advantageously the sampling device is a syringe device
which sucks the liquid through the cell to then return it
into the container 11 after measurement. This avoids waste
of liquid even with high measurement frequency.
The analysis device can also comprise circulation of
washing liquid, advantageously water or having an aqueous
base with appropriate additives, which could be added on
command through a valve 23 (to replace the dyestuff liquid
intercepted by a valve 24) and drained through a valve 25.
Thus it is possible to ensure that in the reading cell
there remains no residue capable of affecting the
measurements.
In addition, the water coming from the outside is necessary
for calibration of the device. The spectrophotometer has
high resolution in the visible and is advantageously
connected by optical fibers 21,22 to the reading cell 18.
FIG 2 shows diagrammatically in greater detail an
advantageous embodiment of the reading cell 18. As may be
seen in the figure, the reading cell has a passage 26 for
the liquid between one light emitting surface 27 and a
reading surface 28. The surface 27 is connected through the
optical fiber 21 to an appropriate light source 29 while
the facing reading surface 2 8 is connected through the
optical fiber 22 to the sensor 30 of the spectrophotometer.
One end of the passage 26 is connected through a duct 31 to
the dip container while the other end of the passage is
connected through a duct 32 to the controlled suction
device 19. The detected measurement light passes thus
through the liquid thickness which is formed between the
two faces 27 and 28 after the passage from the
spectrophotometer which performs the spectroscopic
analysis.
The gauge 'd' of the reading passage 26 can be changed with
precision by means of the controlled movement of the
surface 27 by an actuator 33, for example a stepping motor.
In this manner, before each measurement the control device
15 can adjust the gauge 'd' for measuring on the
spectrophotometer a peak of absorbance included between
minimum and maximum values predetermined to be optimal for
correct measurement. Thanks to the changeable optical path
it is possible to perform the readings in the entire range
of concentrations which might be of interest by adopting
the best reading conditions of the instrument based on the
behavior in absorbance of the signal and in particular on
the peak values.
Indeed, instrumental analysis of concentrations with a
spectrophotometer is based on the well known law of Lambert
and Beer which is applicable within a certain range of
absorbance proportionate to the dyestuff concentration. At
high dyestuff concentrations, in addition to leaving the
linearity range, instrumental reading problems can arise
because of the low signal and resulting possible confusion
with the instrument's background noise. In the prior art of
laboratory analysis it is necessary to perform a dilution
and enter the resulting ratio in the calculation. This
system would however be too costly to apply in an in-line
automatic measurement since it is extremely difficult to
obtain accurate dilutions automatically. There would also
be a loss of dip since it is not possible to add the sample
again at the cost of changing the dip ratio or having
unacceptable loss of dyestuff in small machines.
In the machine in accordance with the present invention all
this is avoided by vising a variable step reading probe
allowing the use of reading gauges of a magnitude inversely
proportionate to the absorbance or proportionate to the
transmittance (dyestuff concentration) of the dip.
The passage gauge is variable in a range between 0 and
25 mm and advantageously between 0 and 10 mm with steps
around 0.01 mm or even less.
The difficulty of determining the size of the gauge because
of the however limited mechanical construction inaccuracies
of the probe give as a result an effective minimum
absorbance value different from 0 and different from one
instrument to another when the distance 'd' is reduced to
the minimum possible quantity, i.e. when the actuator 33 is
operated to take the surfaces 27,28 toward mutual contact.
To avoid this, a special system allowing calculation of
this space and bringing back the values read to the nominal
calculation values was defined. The corrected values are
used to set the optimal reading step by starting the
stepping motor. The reading can always be performed
automatically this way in an optimal manner.
Since for equal liquid the relationship between absorbance
and gauge is linear, to compensate for the residual space
the actuator 33 is controlled by the electronic control and
calculation device 15 to perform measurements on the same
liquid for different ' d' gauges, for example between 0 mm
and 1 mm, which must give a straight line in the
absorbance-gauge graph. If the gauge 0 does not correspond
to the actual contact of the surfaces 27,28 the resulting
straight line will not pass through the zero but will
intersect the axis of the gauges at a negative point
corresponding to the residual gauge which can thus be
calculated, memorized and used by the electronic device to
compensate for the normal measurements.
This results in an indirect optical manner of calculating a
mechanical gauge otherwise difficult to evaluate because of
its possible scantiness and because it is important to
evaluate it with the probe assembled.
Correct calculation of this parameter always influences the
results of the measurements progressively more as the
measurement gauge decreases.
The parameter memorized by the electronic device remains
linked to the specific measurement device.
It is now clear that the preset purposes have been
achieved. During operation the machine will perform a
dyeing cycle while the detected and possibly recorded data
will be processed in the device 15 to find the data on
concentration of the dyestuffs in the dip. The correlation
of dyestuff concentrations with time, temperature, pH,
salinity, pump flow rate (in dip circulation equipment) or
material recirculation speed (in equipment with the goods
moving), supplies data on the rising dynamics of the
dyestuffs on the material being dyed (dip depletion). In
addition, calculations covering the full range of
wavelength measurement of the spectrophotometer with the
squared minimums method as an alternative to or in
combination with calculation based on neural or similar
networks can be used. The system is very accurate and
reliable compared with for example prior art proposals
where it is attempted to analyze the liquid by means of
simple colored filters.
The data taken and calculated can be used for optimization
of future processing or for changing dip parameters in real
time. The control device can then even take action on the
process parameters by means of the above mentioned
appropriate actuators 34.
With the machine in accordance with the present invention
it is possible to adjust and optimize the rise of the
dyestuffs on the products to be dyed while optimizing
processing times, dyeing uniformity and control of dyestuff
quantities drained into the sewage et cetera. It is also
possible to optimize the rise of the dyestuffs on the
material to be dyed by changing one of more process
variables. It is also possible to have accurate indication
of dip depletion and the percentages of each dyestuff of
the formula with each reading.
Sampling of the concentration measurements can be performed
with high frequency with resulting identification of
deleterious transients for the correctness and quality of
the dyeing process and with the capability of fast,
accurate action during the process.
All this would be impossible with the costly prior art
operations of dye dip sampling, laboratory control and the
resulting loss of the dip portion taken. Loss of dip and
the need for a long laboratory tie up among other things
make possible in practice only a limited number of
samplings and analyses for each processing cycle and, in
any case, the resulting data can serve if at all for
improvement of subsequent processing but not as self-
adjustment of the cycle underway.
Naturally the above description of an embodiment applying
the innovative principles of the present invention is given
by way of non-limiting example of said principles within
the scope of the exclusive right claimed here. For example,
depending on the specific dyeing processes the machine
could comprise appropriate additional members and known
devices for the performance of such processes.
CLAIMS
1. Dyeing machine comprising a container (11) in which
products to be dyed are placed, a source (12) of coloring
liquids adding liquids on command into the container to
realize a dye dip, a unit (13) to circulate the dye dip
with respect to the product, spectroscopic analysis means
to perform a spectroscopic analysis on the liquids and an
electronic control and calculation device (15) receiving
the spectroscopic analysis data and calculating therefrom
the concentrations of the various dyes in the dip on the
basis of previously memorized spectroscopic information for
the individual dyes, characterized in that the spectroscopic
analysis means comprise a sampling and analysis device (14),
which during the dyeing process automatically takes liquid
samples from the container to a reading cell (18), at
intervals, and performs a spectroscopic analysis on the
taken samples in the reading cell (18).
2. Machine in accordance with claim 1, characterized in
that the sampling and analysis device (14) has an analyzed
samples drain connected to the container (11) to return the
samples into the container.
3. Machine in accordance with claim 1, characterized in
that the sampling and analysis device (14) comprises a
reading cell (18) having a passage (26) for the liquid with
controlled variable gauge (d) and through said gauge (d) is
made to pass a measuring light detected, after the passage,
by a spectrophotometer (20) sending the data to said
electronic device (15) which performs the spectroscopic
analysis for calculation of the concentrations.
4. Machine in accordance with claim 3, characterized in
that before each measurement the gauge (d) of said passage
(26) in the reading cell (18) is adjusted on command by the
electronic device (15) to detect at the spectrophotometer
outlet an absorbance peak included between the predetermined
maximum and minimum values.
5. Machine in accordance with claim 3, characterized in
that the passage gauge (d) is adjusted on command to have a
reading gauge of a magnitude inversely proportionate to the
liquid absorbance.
6. Machine in accordance with claim 3, characterized in
that the passage gauge (d) is variable in a range included
between 0 mm and 25 mm with steps around 0.01 mm.
7. Machine in accordance with claim 3, characterized in
that the passage (26) in the reading cell (18) is connected
on one side to said container (11) and on the other side to
a controlled suction device (19) for sucking liquid from
the container to the cell and vice versa.
8. Machine in accordance with claim 7, characterized in
that the suction device (19) is a syringe aspirator.
9. Machine in accordance with claim 1, characterized in
that it comprises dip physical magnitude detection sensors
(17) whose measurements are sent to an electronic device (15)
which correlates said measurements with the concentrations
calculated by the spectroscopic analysis.
10. Machine in accordance with claim 9, characterized in
that the physical magnitudes detected include one or more
magnitudes chosen from among temperature, pH and salinity
of the dip and speed of circulation of the dip with respect
to the product.
11. Machine in accordance with claim 1, characterized in that
the electronic device (15) which receives the spectroscopic
analysis data and calculates therefrom the concentrations
of the various dyestuffs in the dip compares the calculated
concentrations with a preset behavior in time and commands
dyeing parameters on the basis of the results of the
comparison.
12. Machine in accordance with claim 11, characterized in
that the dyeing parameters include one of more magnitudes
chosen from among temperature, pH and salinity of the dip
and circulation speed of the dip with respect to the
product.
13. Machine in accordance with claim 3, characterized in
that during a calibration phase of the spectroscopic analysis
device (20) said device is commanded by the electronic
control and calculation device (15) to perform a series of
measurements of absorbance of the liquid with different
gauge (d) of said passage (26) with the electronic device
(15) calculating a gauge-absorbance line identified by the
series of measurements and memorizing as residual gauge the
intersection of said line with the axis of the gauges with
the residual gauge being subsequently used by the
electronic device for correcting the gauges used in
subsequent measurements.
14. Machine in accordance with claim 3, characterized in
that during a calibration phase of the spectroscopic analysis
device (20) said device is commanded by the electronic
control and calculation device (15) to reduce to the
minimum the gauge (d) of said passage (26) and measure the
absorbance of a liquid remaining in the residual gauge with
said absorbance measurement being memorized by the
electronic device (15) and used subsequently for correcting
the subsequent measurements by said residual gauge.
15. Machine in accordance with claim 3, characterized in
that it comprises a circuit (23, 25) for controlled inlet
and extraction of a washing liquid in the reading cell (18).
16. Machine in accordance with claim 13, characterized in
that the washing liquid is water or water based with
additives.

A dyeing machine comprises a container (11) in which
products to be dyed are placed, a source (12) of coloring
liquids adding liquids on command into the container to
realize a dye dip, and a unit (13) to circulate the dye dip
with respect to the product. During the dyeing process a
sampling and analysis device (14) automatically takes
samples of liquid from the container at intervals and
performs a spectroscopic analysis thereon. An electronic
control and calculation device (15) receives the
spectroscopic analysis data and calculates therefrom the
concentrations of the various dyestuffs in the dip. The
behavior thus obtained of the dip can be memorized for
future use and/or can be used to command appropriate
corrective parameters of the dyeing process.

Documents:

1857-KOLNP-2004-(06-01-2012)-FORM-27.pdf

1857-KOLNP-2004-ABSTRACT 1.1.pdf

1857-KOLNP-2004-ABSTRACT-1.2.pdf

1857-kolnp-2004-abstract.pdf

1857-KOLNP-2004-AMANDED CLAIMS-1.1.pdf

1857-KOLNP-2004-AMANDED CLAIMS.pdf

1857-kolnp-2004-claims.pdf

1857-KOLNP-2004-CORRESPONDENCE 1.2.pdf

1857-KOLNP-2004-CORRESPONDENCE-1.1.pdf

1857-kolnp-2004-correspondence.pdf

1857-KOLNP-2004-DESCRIPTION (COMPLETE) 1.1.pdf

1857-KOLNP-2004-DESCRIPTION (COMPLETE)-1.2.pdf

1857-kolnp-2004-description (complete).pdf

1857-KOLNP-2004-DRAWINGS 1.1.pdf

1857-KOLNP-2004-DRAWINGS-1.2.pdf

1857-kolnp-2004-drawings.pdf

1857-KOLNP-2004-FORM 1 1.1.pdf

1857-KOLNP-2004-FORM 1-1.2.pdf

1857-KOLNP-2004-FORM 1-1.3.pdf

1857-kolnp-2004-form 1.pdf

1857-kolnp-2004-form 18.pdf

1857-KOLNP-2004-FORM 2 1.1.pdf

1857-KOLNP-2004-FORM 2-1.2.pdf

1857-kolnp-2004-form 2.pdf

1857-KOLNP-2004-FORM 3 1.1.pdf

1857-KOLNP-2004-FORM 3-1.2.pdf

1857-KOLNP-2004-FORM 3-1.3.pdf

1857-kolnp-2004-form 3.pdf

1857-kolnp-2004-form 5.pdf

1857-kolnp-2004-international preliminary examination report.pdf

1857-kolnp-2004-international publication.pdf

1857-kolnp-2004-international search report.pdf

1857-KOLNP-2004-OTHERS 1.1.pdf

1857-KOLNP-2004-OTHERS 1.2.pdf

1857-KOLNP-2004-PA.pdf

1857-kolnp-2004-pct request form.pdf

1857-KOLNP-2004-PETITION UNDER RULE 137.pdf

1857-KOLNP-2004-REPLY TO EXAMINATION REPORT.pdf

1857-kolnp-2004-specification.pdf

1857-kolnp-2004-translated copy of priority document.pdf


Patent Number 249432
Indian Patent Application Number 1857/KOLNP/2004
PG Journal Number 42/2011
Publication Date 21-Oct-2011
Grant Date 19-Oct-2011
Date of Filing 06-Dec-2004
Name of Patentee DYECONTROL BY LORIS BELLINI E ZAITEX S.R.L.
Applicant Address VIA BIANCA DI SAVOIA 17, I-20122 MILANO
Inventors:
# Inventor's Name Inventor's Address
1 ROSSI MARCO VIA LAGO DI COMO 42, I-36100 VICENZA
2 BELLINI GIOVANNI VIA GAVINANA, 35, I-20024 GARBAGNATE MILANESE
3 MENEGHELLO GIUSEPPE CONTRADA ZUCCANTE 13, I-36076 RECOARO TERME
PCT International Classification Number D06B 23/28
PCT International Application Number PCT/EP2003/05285
PCT International Filing date 2003-05-20
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 MI2002A001192 2002-05-31 Italy