U.S. patent number 3,805,020 [Application Number 05/311,564] was granted by the patent office on 1974-04-16 for thermal treatment of textiles.
Invention is credited to Emile Bernard Bates.
United States Patent |
3,805,020 |
Bates |
April 16, 1974 |
THERMAL TREATMENT OF TEXTILES
Abstract
A device for heating and controlling the surface temperature of
a cylindrical drum wherein a member is located on the central axis
of the drum and in which a plurality of separate heating coils are
disposed longitudinally along the length of said drum for the
purpose of heating the drum, there being an element for controlling
the current to each separate coil and heat sensing devices
contacting the outer periphery of the drum and another element
controlled by said heat sensitive devices according to the
temperature of the outer surface of the drum to vary the current to
the heating coils.
Inventors: |
Bates; Emile Bernard
(Leicester, EN) |
Family
ID: |
23207462 |
Appl.
No.: |
05/311,564 |
Filed: |
December 4, 1972 |
Current U.S.
Class: |
219/469; 219/471;
374/E13.01 |
Current CPC
Class: |
H05B
3/16 (20130101); G01K 13/08 (20130101); G05D
23/1934 (20130101); H05B 3/0095 (20130101); F26B
13/183 (20130101); G05D 23/22 (20130101); G05D
23/24 (20130101); G05D 23/1909 (20130101) |
Current International
Class: |
F26B
13/18 (20060101); F26B 13/10 (20060101); G01K
13/00 (20060101); G01K 13/08 (20060101); G05D
23/20 (20060101); H05B 3/16 (20060101); H05B
3/00 (20060101); G05D 23/24 (20060101); G05D
23/22 (20060101); H05b 001/02 () |
Field of
Search: |
;219/469-471,506
;337/276 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gilheany; Bernard A.
Assistant Examiner: Bell; F. E.
Attorney, Agent or Firm: Paul & Paul
Claims
1. In a sublimatic printing system means for heating and
controlling the surface temperature of a rotating cylindrical
textile drum comprising a fixed member located on the central axis
of the drum, a plurality of separate heating coils connected
longitudinally along said member, means for controlling the current
to each said separate coil, heat sensing devices located outside
said drum and contacting the outer periphery of the drum, said heat
sensing means being maintained in contact with said outer periphery
by spring means, and means, controlled by said heat sensing devices
according to the temperature of the outer surface of the
2. Means according to claim 1 in which the means controlled by the
heat sensitive devices acts to control the current to one or more
of the
3. Means according to claim 2 in which the electrical heating
comprises
4. Means according to claim 3 in which the wire is held in spaced
relationship relative to the member by formers extending radially
from
6. Means according to claim 1 in which the heat sensing devices
comprise a
7. Means according to claim 1 in which heat sensing devices
comprise a
8. Means according to claim 7 in which the thermocouple junction is
an
9. Means according to claim 1 in which the heat sensing devices are
held in contact with the outer peripheral surface of the drum by a
coil spring.
10. Means according to claim 1 in which an output from the heat
sensing devices form a part of a Wheatstone bridge circuit in which
a galvanometer
11. Means according to claim 10 in which calibration of the
galvanometer is arranged to actuate an electromagnetic switch to
control the current to
12. Means according to claim 1 in which the outputs from heat
sensing devices are connected directly to a galvanometer having a
needle with an aperture therein and arranged to move relative to a
photoelectric cell and with a point source of light arranged to
direct on to the aperture in the needle so that when the source of
light, needle and photoelectric cell are in register the
photoelectric cell is energised and is arranged to
13. Apparatus for providing precise temperature control in the
range utilized for sublimatic printing of fabrics comprising:
a cylindrical drum at least three feet in diameter;
a fixed shaft member located on the central axis of said drum;
gear means for rotating said drum about said shaft member;
a plurality of electrical heating coils arranged successively along
said shaft, each coil providing radiant heat for a different
portion of said drum, said coils having heating capacity to
maintain said drum in the range of 200.degree.C to
250.degree.C;
a plurality of temperature sensing means located exterior to and in
contact with the outer surface of said drum, each of said
temperature sensing means including a thermistor located on an
asbestos insulator and maintained in position by spring means and a
non-movable guide rod;
galvanometer means having a needle, the position of said needle
being determined by the electrical current from all of said
temperature sensing means, the body of said needle defining an
aperture therein;
a point light source directed onto the aperture of said needle;
a photoelectric cell located at a predetermined point in the travel
of said needle, said cell being energized when said light source
and said aperture are in register therewith; and
control means for developing electrical current in said coils
except when said photoelectric cell is energized.
Description
BACKGROUND OF INVENTION
This invention is for improvements in or relating to the heating of
cylindrical drums for use in the textile industry. It is well
established that for a number of different purposes it is requires
to heat textile fabrics. Among the principal reasons for heating
textile fabrics is the need to set such fabrics. This applies in
the case of synthetic plastic fabrics of the polyamide and
polyester groups of yarns where it is necessary after formation of
the yarn into a fabric either by way of weaving or a knitting
process to relax the tensions in the yarn and to set the fabrics in
the desired shape. Conventionally, such fabrics can be heat treated
on the stentor which may involve the use of heated gases contacting
the surface of the fabric or may be heated by staying in contact
with the heated surface of a rotating drum. Various means are known
for heating the drum. Alternatively, and in some instances, heat
setting of fabrics is done by boarding and placing the boarded
garment inside a steam autoclave.
In all instances it is desirable that the fabric which is being
heat treated shall be uniformly heat treated. That is to say that
all parts of the fabric are subjected to substantially the same
temperature and pressure and it will be appreciated that in a
stentor where heated gases are passing over the fabric all parts of
the fabric will be subjected to the same temperature. Similarly,
where a garment is placed in a steam autoclave the temperature
within the autoclave will be uniform or at least around the garment
it will be uniform and so that all parts of the garment or fabric
will be subjected to the same temperature. However, in the case of
a fabric contacting the surface of a heated drum slight variations
in the temperature of the drum may exist causing variations in the
effective treatment of the fabric.
In addition to the heat treatment of fabrics for the purpose of
heat setting the yarn of which these fabrics are formed, it has in
recent times become known to dye textile fabrics by a printing
process involving sublimable dyestuffs. In this process the
dyestuff is mixed with a carrier so that it may be applied to an
intermediate layer, usually paper, by a substantially conventional
printing process, usually a gravure printing process but in some
instances by a lithographic printing process. The heat sublimable
dyestuff is vaporised on the application of heat and if the layer
with the printed dyestuff is brought into contact with the undyed
textile fabric and the necessary amount of heat applied to the
paper layer for the necessary period of time and under other
desirable conditions, the dyestuff sublimates and in its vapour
state imparts colour to the textile fabric. It has been found that
this process may be perfected to dye textile fabrics up to six or
even eight colours simultaneously with an extremely accurate
register and involving complex patterns. In order to obtain
uniformity of effect on the textile fabric it is necessary that the
temperature at which the process is carried out is accurately
controlled.
It has for example been found out that variations up to 3.degree.
on one edge of a fabric being dyed by the aforementioned process
can cause marked visual variations in the colour on the final
fabric. In general, the higher the temperature the more the
dyestuff sublimates and the deeper the colour which is imparted to
the fabric. So that if a hot spot is provided during the dyeing a
deeper colour on the final fabric results and where such fabrics
are required for multiple production processes, for dresses and
other similar articles of wearing apparel this variation of colour
is highly undesirable.
DESCRIPTION OF INVENTION
It is an object of the present invention to provide means for
accurately controlling the temperature of a surface suitable for
the treatment of textile fabrics whether for the purpose of heat
dyeing those fabrics or whether for use with the heat transfer
dyeing process as aforementioned.
Accordingly, the present invention provides means for heating and
controlling the surface temperature of a cylindrical drum
comprising a member located along the central axis of the drum, a
plurality of separate heating coils disposed longitudinally along
the axis of the member, means for controlling the current to each
separate coil, a heat sensing device contacting the outer periphery
of the drum and means controlled by the heat sensitive devices
according to the temperature of the outer surface of the drum.
More specifically the present invention provides for a drum or open
ended bowl and of cylindrical form around which the fabric to be
treated passes. The drum is rotated while the fabric is in contact
therewith.
Along the central longitudinal axis of rotation of the drum is
provided a member conveniently a steel tube of austentitic steel
and mounted on this tube are a plurality of separate heating coils.
Conveniently, the heating coils are formed by electrical resistance
wire wound on formers mounted on the tube in spiral manner so as to
form separate and distinct heating coils along the length of the
tube. As viewed in the finished condition the tube will appear as
one continuous heating coil consisting of a spiral length of wire
from one end to the other but in fact the wire will be separated
out into coils of predetermined longitudinal length. The wire will
be wound upon formers conveniently of mica which are secured by
clamps to the tube and extend radially therefrom.
The outer edges of the mica will be serrated and the electrical
resistance wire wound around the tube and held in spaced relation
to adjacent turns by passing into separate slots in the mica. Thus
by connecting the heating coils to a source of electrical current
the interior of the drum may be heated and the heat transfer
through the wall thickness of the drum to the outer surface
thereof.
It will be appreciated that either the one end or both ends or the
central portion or other discrete sections of the drum may be
heated to a higher temperature than other sections by connecting
the appropriate heating coils to a source of current and not so
connecting the others. Thus by switching on and off selected
heating coils the temperature of the outer surface of the drum in
the immediate radial vicinity of the heating coil can be controlled
within surprisingly fine limits of tolerance.
The invention further provides for heat sensing means contacting
the outer surface of the drum in the region of each heating coil so
that by observing these heat sensing means and ensuring that they
are reading a uniform temperature it is possible to control the
temperature of the outer surface of the drum within the same fine
limits of tolerance. The heat sensing device may consist of one of
two different kinds. In the first, a Thermistor being a device
whose electrical resistance varies with temperature is used and in
the other a known electric thermocouple is used, conveniently a
nickel/iron thermocouple. In both instances, the device is lightly
pressed by a coil spring on to the outer surface of the drum and
connected by appropriate means to a galvanometer which may be
calibrated to read directly in degrees of temperature (fahrenheit
or centigrade as required).
In an alternative arrangement, the reading obtained from the heat
sensitive device may be used to control directly the current to the
heating coils. In one particular instance the heat sensitive device
operates a galvanometer with an aperture formed in the needle. A
source of light is arranged to pass through that aperture and to be
detected by a photoelectric cell on the opposite side.
Means are provided for moving the photoelectric cell to a
predetermined position so that when for example the heat sensitive
device has reached a certain temperature and the needle of the
galvanometer has reached a position where the point source of light
is able to pass through the aperture the needle can operate to be
detected by the photoelectric cell, the cell becomes energised and
is arranged to switch off the current to the appropriate heating
coil, thus preventing further rise of the temperature of the outer
surface of the drum at that point. When the surface temperature has
dropped to a predetermined value, the light will not longer reach
the photoelectric cell since the aperture in the galvanometer
needle will have moved out of register and the current to the
heating coil will again be switched on.
Other known arrangements for controlling the current to the heating
coils from the heat sensing devices may be used. For example, the
output may be fed to a transistorised voltage amplifier whose
output may be used to operate a relay for connecting or
disconnecting as the case may be the current to the electrical
heating coils.
DESCRIPTION OF DRAWINGS
In order that the present invention may be more readily understood,
reference is now made to the accompanying drawings, in which:
FIG. 1 is a schematic cross-sectional view of apparatus according
to the present invention;
FIG. 2 is a cross-sectional view showing the arrangement of the
heating coils;
FIG. 3 is a side elevation section of FIG. 2;
FIG. 4 is a schematic view showing one type of heat sensing
device;
FIG. 5 is an alternative heat sensing device;
FIG. 6 is a schematic view of a further heat sensing device for use
with the present invention; and
FIG. 7 is a detailed view of a galvanometer operated by heat
sensing device as used with the present invention.
According to the present invention a cylindrical drum or bowl 1 is
mounted for rotation about bearings 2 and it will conveniently be
driven by means of gearing or belt drive 6.
The fabric to be treated according to the present invention will
contact the outer peripheral surface of the drum 1, be supplied in
a roll provided on a beam and will be led to the drum 1 around
300.degree. or more of arc and thence to a cooling station before
being wound on to a take up beam. Located within the interior of
the drum is a rod 4 around which is located a tube 12 of
austentitic steel. The tube 12 is held in spaced relationship to
rod 4 by spider arms 4a (FIG. 2). The rod 4 is supported upon end
bearers 5. The tube 12 is a support for formers for electrical
heating wire 10. The formers comprise mica strips 11 which are held
to the surface of the tube 12 so as to extend radially therefrom by
clamps 13 bolted to the outer surface of the tube 12. As seen in
FIG. 2 six such radially extending formers are provided and the
outer edge of the formers is slotted at 11 as seen in FIG. 3. The
heating coils are formed of electrical resistance wire 10 which is
wound around the formers and into the slots 11 in separate and
distinct sections as indicated Z1-Z6 in FIG. 1. The termination of
the electrical heating wire is brought to an electrical connector
15 in each zone Z1-Z6 respectively. The ends of the electrical
heating wire are then taken by appropriate electrical wires through
a non-conductive junction box 7 for coupling up the electrical feed
terminates 15 to control switching. On the exterior peripheral
surface of the drum 1 are provided heat sensors 8 opposite each of
the electrical heating coils mounted on their respective formers.
In FIG. 1 these heat sensors are indicated TP1-TP6 respectively
opposite each of the electrical heating coils Z1-Z6.
The heat sensing devices may be of any convenient form but
particularly there is illustrated in FIG. 4 a thermal junction 16
which is formed into a spring bow by passing the metallic thermal
junction material around insulators 17 and connecting by means of
electrical connecting metal 18 to the insulator 19 and thence by
electrical leads 20 to appropriate control means.
Conveniently, the thermal junction will be of the iron/nickel type.
It is necessary to maintain one end of the thermal junction cool
while the other is responsive to the temperature of the outer
surface of the periphery of the drum 1.
In FIG. 5 an arrangement is shown in which a thermal junction
member 23 is held in contact with the outer surface of the drum 1
other than by the spring bow. In this instance, a
polytetrafluoroethylene insulating block 21 houses the thermal
junction 23 and the block including the junction 23 is biased
against the surface of the bowl 1 by a coil spring 22.
In an alternative construction illustrated in FIG. 6, a Thermistor
member 25 located on an asbestos insulator 24 is lightly pressed
against the surface of the drum 1 by a coil spring 28 acting
against a fixed clamp 27 and with the coil spring and the asbestos
insulator being guided along a central non-movable rod 26. The
leads 20 from the heat sensing device are connected to appropriate
means for determining the temperature of the outer surface of the
drum 1 and in FIG. 6 such leads 20 are connected to one quarter of
a conventional Wheatstone bridge circuit illustrated generally 29
and including the resistors R1, R2, R3 and R4 and in which R1 is
the resistance of the Thermistor 25 and R2 is the resistance of a
galvanometer. R3 and R4 are conventional variable resistances in
order to obtain the proper readings. The circuit may be energised
by 2 volts D.C. which is obtained by a half way rectified A.C.
current. According to the conventional formula of R1/R2 = R3/R4 it
is possible to adjust the values of R3 in order to give a different
temperature range and a changeover switch 30 is provided for
bringing into operation either the resistance of A or B to give a
different temperature range on the scale of the galvanometer
forming R2. Conveniently, such ranges may be arranged by
appropriate values of the resistors to give a reading of from
20.degree. to 150.degree.C on one scale and from 130.degree. to
250.degree.C on the other scale.
It will be appreciated that the galvanometer is reading the voltage
flowing across the resistor R4 and the resistance between the
junctions of the bridge which is formed by a coil 31. The coil 31
may be arranged to actuate an electromagnetic switch 33 when the
galvanometer reads a predetermined value and on closing of the
contacts of the electromagnetic switch 33 an electrical connection
to leads 32 to provided which may be arranged to connect the source
of electricity to the appropriate electrical heating coil in one of
the zones Z1 to Z6 as previously described. Thus by determining the
temperature of the surface of the bowl 1 it is possible
automatically for the electrical heating coil to be switched on or
off according to the pre-setting of the galvanometer or other means
responsive to the determination of temperature by the heat sensing
device.
In an alternative arrangement illustrated diagrammatically in FIG.
6 the galvanometer indicated at 34 has a needle 35 formed with an
aperture 36 therein and a point source of light is arranged to be
directed on to this aperture 36. A photoelectric cell on the
opposite side of the needle from that on which the point source of
light is located may be adjusted relative to the scale on reading
of the needle 35 and the arrangement is such that when the
corresponding electrical heating coil remains switched on only
while point source of light, the aperture 36 and the photoelectric
cell, not illustrated, are not in register. Once they are all in
register the light energises the photoelectric cell and this is
arranged to disconnect the current to the appropriate heating
coil.
It will be appreciated that as the surface cools down and the
galvanometer needle moves to bring the aperture 36 out of register
the photoelectric cell will be de-energised and the circuit re-made
to the electrical heating coil.
It will be appreciated that by the present invention it is possible
accurately to come within fine limits of tolerance to control the
surface temperature of a drum suitable for use with textile
materials for the treatment thereof.
* * * * *