Sample package dyeing machine

Abstract

 A dyeing machine (2) for dyeing a sample yarn package (9) comprises a kier (2), a spindle (7) mounted in the kier for supporting a sample yarn package, and a dye liquor circulation system (25) operable to circulate dye liquor through the sample yarn package with inside-to-out and outside-to-in flow directions, the kier and the spindle configured to accommodate a single sample yarn package with a weight less than 1.2 kg, and the machine having an operating volume such that a single sample yarn package weighing less than 1.2 kg can be dyed using a liquor ratio of substantially 1:6.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a package dyeing machine for dyeing sample yarn packages.

[0002] Conventionally, textile yarn and thread is dyed by being formed into a package that is mounted onto a spindle inside a package dyeing machine. Many packages may be loaded into a single machine. A standard yarn package weighs about 1.2 kg and hence comprises a substantial quantity of yarn. Dye liquor is circulated through the yarn packages in both an inside-out flow direction (liquor flowing from the inside of the spindle outwards through the yarn to the exterior of the package) and an outside-in flow direction to ensure even dyeing. The ratio of the volume of dye liquor to the amount of yarn (liquor ratio) determines the level of dyeing, and a particular liquor ratio will be required to achieve a desired colour result.

[0003] In the yarn and thread dyeing industry, customers often require samples for approval. Customarily, the sample is provided by dyeing a standard 1.2 kg yarn package. This amount of yarn is generally very much greater than that needed for approval, so that sample production can be wasteful of chemicals, dyestuff, yarn/thread and energy.

[0004] To address this, a smaller, sample-sized package may be dyed, having a weight below the 1.2 kg standard. However, if a smaller package is used, it is difficult to attain a liquor ratio equal to that of a large volume production dyeing machine dyeing many standard packages. This difference in liquor ratio produces a different dyeing effect so that the sample package will likely have a colour variation compared to the final production packages, thus rendering the production of a sample somewhat useless. Also, there are difficulties in direct adoption of the dye formula used to produce the sample into a large-scale production process in a production machine, since repeatability is difficult to ensure.

[0005] To achieve an equivalent liquor ratio in the sample dyeing as in later production, it is possible to produce samples using a machine which shakes small lengths of thread or yarn in a container holding a volume of dye liquor. Although this addresses the issue of liquor ratio consistency between samples and final production, the dyeing mechanism is totally different from that produced by the inside-out, outside-in flow and control over dye liquor dosing used in a production package dyeing machine. Therefore, the dye formula used in the production machine cannot be directly applied to this type of sample dyeing machine, again giving differences between the sample and the production yarn.

SUMMARY OF THE INVENTION

[0006] Accordingly, a first aspect of the present invention is directed to a dyeing machine for dyeing a sample yarn package comprising: a kier; a spindle mounted within the kier for supporting a sample yarn package inside the kier; and a dye liquor circulation system operable to circulate dye liquor through a sample yarn package supported on the spindle; wherein the kier and the spindle are configured to accommodate a single sample yarn package with a weight less than 1.2 kg, and the machine has an operating volume such that a single sample yarn package weighing less than 1.2 kg can be dyed using a liquor ratio of substantially 1:6.

[0007] A machine of this configuration can therefore be used to produce small size samples of dyed yarn using a liquor ratio which matches that commonly used in large production-scale package dyeing machines designed to accommodate many large yarn packages. Use of the same liquor ratio for producing a sample as will be used for eventual production of the yarn allows the same dyeing effect to be achieved in the sample as in the final product. The sample is therefore truly representative of the end product, and allows a proper sample evaluation to be carried out. Also, the small size of the machine, configured to accommodate just one small sample package and a correspondingly small liquor volume, allows savings in space, energy, time and raw materials.

[0008] The dye liquor circulation system may be operable to circulate dye liquor through the sample yarn in both an inside-to-out flow direction and an outside-to-in flow direction. Dyeing cycles using both these flow directions are used in production package dyeing machines. A sample machine that provides this allows samples to be produced that better represent the end product that will be produced by the production machine, because the fluid flow arrangement affects the dyeing result. A dual-directional flow pump may be provided to produce the inside-to-out and outside-to-in flows. This is much better suited to a small sample machine than the combination of a single-directional pump and a complex and bulky reversal device that is commonly used in a production package dyeing machine.

[0009] In some embodiments, the interior of the kier can be pressurised. Pressurisation allows the fluid in the kier to be heated to a higher temperature without evaporation. Thus, a smaller initial volume of fluid can be used to achieve the desired liquor volume, because there is little or no loss to evaporation. The dyeing machine may comprise an airpad operable to pressurise the interior of the kier.

[0010] The machine -may further comprise a fluid outlet via which fluid can be extracted from the kier. For example, the fluid outlet may comprise a needle valve. This allows water to be taken at the start of a dyeing process, for the preparation of the dye liquor, and also allows a sample of dye liquor to be extracted later in the dyeing process. The liquor sample can be assessed to determine whether the desired dyeing result has yet been achieved, so that the dyeing process can be carefully monitored, giving a quality yarn sample.

[0011] Also, the machine may further comprise a fluid inlet via which fluid can be introduced into the kier. The fluid inlet may comprise a syringe. The prepared dye liquor can be added using the fluid inlet. A syringe allows highly precise control of the addition of the dye liquor, which can affect the dyeing result.

[0012] In some embodiments, the dyeing machine may further comprise a cooling jacket disposed around the kier. Also, the dyeing machine may further comprise an electrical heating element inside the kier operable to heat fluid inside the kier. A cooling jacket and an electrical heating element can replace the heat exchanger commonly used in a large production yarn package dyeing machine. These smaller and more compact components are much more suitable for a small sample machine, which will perhaps be used in a laboratory without a supply of the steam used in a heat exchanger.

[0013] The spindle may comprise an inner closed volume into which circulating dye liquor cannot penetrate; and an outer wall around which a yarn package can be mounted and through which circulating dye liquor can pass to and from the yarn package, the outer wall surrounding the inner closed volume to define an annular passage around the inner closed volume, and the annular passage connected to the dye liquor circulation system. The closed inner volume of the spindle occupies space within the machine that would otherwise be filled with dye liquor. Hence the overall operating volume is reduced, and the required liquor ratio can be provided for a smaller weight of yarn sample.

[0014] The dyeing machine may further comprise an electronic controller operable to provide automated control of a dyeing process carried out in the kier. The dyeing process can thereby be more accurately carried out. Also, fewer operators are needed in a laboratory producing many samples.

[0015] Further in this regard, the machine may comprise one or more additional kiers with associated spindles and dye liquor circulation systems, the electronic controller being further operable to provide individual automated control of dyeing processes carried out in each kier. This allows more samples to be produced in a smaller space, and also further reduces the number of operators required.

[0016] A second aspect of the present invention is directed to a spindle for supporting a yarn package inside a kier of a dyeing machine, the spindle comprising: an inner closed volume into which circulating dye liquor cannot penetrate; and an outer wall around which a yarn package can be mounted and through which circulating dye liquor can pass to and from the yarn package, the outer wall surrounding the inner closed volume to define an annular passage around the inner closed volume, and the annular passage connectable to a dye liquor circulation system operable to circulate dye liquor through a yarn package supported on the spindle.

[0017] While a spindle of this kind is particularly applicable to a sample yarn package dyeing machine according to the first aspect of the invention, it may also be of use in larger machine as a means for changing the liquor ratio.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] For a better understanding of the invention and to show how the same may be carried into effect reference is now made by way of example to the accompanying drawings in which:

Figure 1 shows an exterior perspective view of a sample yarn package dyeing machine according to an embodiment of the present invention;

Figure 2 shows a cross-sectional view through a kier of the machine of Figure 1;

Figure 3 shows a further cross-section view through the kier of the machine of Figure 1;

Figures 4A and 4B show schematic illustrations of inside-to-out and outside-to-in dye liquor flow directions provided by the machine of Figure 1;

Figure 5 shows a schematic representation of a dye liquor circulation system of the machine of Figure 1;

Figure 6 shows a schematic representation of a sample yarn package dyeing machine according to a further embodiment; and

Figure 7 shows a cross-sectional side view of a spindle for use in a package dyeing machine according to another embodiment.

DETAILED DESCRIPTION

[0019] Figure 1 shows an exterior view of a sample yarn package dyeing machine according to an embodiment of the invention. The machine has an overall small size suitable for dyeing a single yarn package of weight below the standard yarn package weight of 1.2 kg. The machine can be easily accommodated in a laboratory, and is hence very convenient. More importantly, the machine is configured to operate and function in a equivalent manner to a large scale production yarn package dyeing machine, so that the production dyeing mechanism and liquor ratio can be replicated. Thus, samples of dyed yarn that can be accurately replicated on a production scale can be produced.

[0020] In particular, the machine is configured to operate with a liquor ratio of substantially 1:6. This is the ratio commonly used in production yarn package dyeing. The liquor ratio is the ratio of the amount of dye liquor to the amount of yarn needed to produce a desired dyeing result. A package dyeing machine will have a minimum volume of dye liquor below which it cannot function, this being the volume of liquor required to fill enough of the machine for the dye liquor to be properly circulated around the machine and through the yarn package(s). This puts a corresponding restraint on the amount of yarn which can be dyed in the machine at an appropriate liquor ratio. In the present invention, the machine has an operating volume such that it can accommodate one yarn package weighing less than 1.2 kg and a corresponding amount of circulating dye liquor to give a liquor ratio of substantially 1:6.

[0021] The machine 20 shown in Figure 1 comprises a cylindrical tank known as a kier 2 into which a sample yarn package can be placed for dyeing. The kier 2 is closed by a cover 1. A small pipe 21 is connected to the kier 2. The pipe 21 is provided with a fluid outlet in the form of a needle valve 4, which can be used to extract small volumes of fluid (water or dye liquor) from the kier. Other suitable fluid outlet devices may be used instead. Also, the pipe is provided with a fluid inlet through which fluid (water, dye, dye liquor) can be introduced into the kier. Use of the fluid inlet to add dye or dye liquor to the kier means that it can be thought of a liquor dosing system. In this example, the fluid inlet comprises a syringe 3, so that small volumes of fluid can be injected into the kier in a precise and controlled manner.

[0022] The kier 22 is mounted on a housing 22 which encloses an electronic controller 5, having a control pad accessible from the exterior of the housing 22. The controller 5 is operable to control the various components of the dyeing machine 20 in an automated manner so that a dyeing procedure can be performed automatically. Information and data can be entered to the controller 5 by the control pad, for example to program the controller to perform a particular dyeing procedure. The controller 5 may be implemented using hardware, software or a combination of hardware and software

[0023] The housing 22 also accommodates a pipe network providing a dye liquor circulation system for circulating dye liquor through the machine. This will be described in more detail later. Enclosure of the pipes in this manner enhances safety, for example if a leak occurs or to prevent human contact with pipes containing high temperature fluid. Also, the appearance of the machine is improved.

[0024] Figure 2 shows a cross-sectional side view of the kier 2. Mounted centrally from the base of the kier 2 is a spindle 7 extending vertically upwards. The spindle 7 receives and supports a yarn package 9 having a central aperture that slots over the spindle 7. A locking cap 11 is provided at the upper end of the spindle 7 for securing the yarn package 9 in place during the dyeing process. In this example, the locking cap 11 screws onto the spindle 7 via co-operating screw threads on the locking cap and the top of the spindle, but other methods of attachment may be used instead.

[0025] The kier 2 also receives a volume of fluid 10 (dye liquor or water depending on the stage of the dyeing process) in which the yarn package 9 is submerged. The fluid 10 is circulatable through the yarn package 9 by the action of the dye liquor circulation system.

[0026] In this example, the kier 2 also contains an electrical heating element 8 for heating the fluid 10 in the kier 2. As illustrated, the heating element 8 is disposed in the base of the kier 2, but may be positioned elsewhere if preferred.

[0027] Also, this embodiment includes an airpad 6 disposed inside the upper part of the kier 2, for raising the pressure of the interior of the kier 2. An alternative pressurising apparatus may be used instead, or no pressurising apparatus. A dial 24 provided on the exterior of the kier 2 indicates the pressure inside.

[0028] Figure 3 shows a further cross-section of the kier 2, according to an embodiment in which the kier is provided with a cooling jacket 12. The cooling jacket 12 surrounds the exterior side walls of the kier 2, and defines a volume around the kier 2 through which a coolant, such as cooling water, can flow over the surface of the kier 2 to remove heat. The cooling jacket has a coolant inlet 16 towards its upper end and a coolant outlet 14 towards its lower end, by which coolant can be flowed through the jacket, as indicated by the arrows.

[0029] The dyeing machine 20 is configured to provide inside-to-out and outside-to-in dye liquor flow through the yarn package, to emulate the dyeing mechanism of a production dyeing machine.

[0030] Figures 4A and 4B illustrate these two flow arrangements. A yarn package 9 is mounted on a spindle 7 inside a kier (not shown in these Figures). The spindle 7 has a hollow passage inside for the flow of fluid, and its exterior surface, around which the yarn package 9 is mounted, is permeable to fluid flow (such as by having a plurality of perforations or other apertures therein). For inside-to-out flow, shown in Figure 4A, dye liquor (or other treatment fluid, including rinsing water) passes up into the hollow passage of the spindle 7, and flows outwards through the spindle exterior surface and then through the yarn package 7, before reaching the main interior volume of the kier. The dye liquor is then returned by the circulation system to the spindle's hollow passage for recirculation through the yarn.

[0031] For outside-to-in flow, shown in Figure 4B, this process is reversed. Dye liquor contained in the kier is drawn through the yarn package 9 and then through the exterior wall of the spindle 7 to the hollow passage, where it leaves through the bottom of the spindle. The liquor is then recirculated back into the main body of the kier.

[0032] Figure 5 shows a simplified schematic representation of a dye liquor circulation system according to an embodiment of the invention, for providing inside-to-out and outside-to-in flow. The circulation system comprises a pipe network 25 (shown in very simplified form in this Figure) that is connected at one end to a fluid inlet/outlet point 26 in the side wall of the kier 2, and at the other end 27 to a fluid inlet/outlet point 27 in the base of the kier 2 that is in fluid communication with the hollow passage 29 inside the spindle 7. Thus, there is a continuous path for fluid from the interior of the kier 2, along pipe network 25 to the hollow passage 29, and through the exterior surface of the spindle 7 and the yarn package 9 back to the interior of the kier 2. The path also allows flow in the opposite direction, so that inside-to-out flow and outside-to-in flow are both provided. To drive the fluid around the path in either direction, as indicated by the arrows, a dual directional pump 28 is located in the pipe network 25 external to the kier 2. The pump can switch between two operation modes, one which pumps the fluid in the inside-to-out direction and one which pumps the fluid in the outside-to-in direction. A pump of this type is compact and able to readily handle the volume of fluid utilised in the machine 20. Hence the pump is well-suited to use with the present invention. In contrast, a production size package dyeing machine typically employs a complicated reversal device operable to switch between two positions to provide both fluid flow directions from a single-directional pump. A reversal device is bulky, and while acceptable for a large production machine, is not suitable for a sample dyeing machine. Not only is it too large for convenient use with a sample dyeing machine, a much more complex pipe network is needed which requires a large liquor volume for smooth fluid circulation. Therefore, small liquor ratios cannot be achieved with small yarn packages. According to an embodiment of the present invention, it is recognised that these drawbacks can be overcome by use of a dual-directional flow pump.

[0033] Operation of the machine 20 will now be described. A sample yarn package 9, weighing less than the 1.2 kg weight of a standard yarn package, is placed onto the spindle 7 inside the kier 2, and the package is secured in place by the locking cap 11. The kier cover 1 is closed, and a dyeing process programmed or initiated via the keypad of the controller 5.

[0034] An appropriate volume of water to achieve the intended liquor ratio of substantially 1:6 is then provided into the kier 2 (for example via an inlet in the circulation system). The water is heated by the electrical heating element 8 to a desired temperature, according to the dyeing to be carried out. A catalyst may be added to increase the speed of the dyeing process. As the water approaches its boiling point (100 degrees centigrade), the interior of the kier is pressurised using the air pad 6. Raising the pressure increases the boiling point of the water, so that the machine can be operated at the required high temperature without vaporisation of the water due to boiling. Preventing vaporisation allows the desired operating liquor ratio to be achieved with a smaller starting volume of water, thus reducing the initial liquor ratio required, and also the overall operating volume needed for the machine. Also, the dual-directional flow pump can operate more smoothly with a lower liquor ratio when the kier 2 is pressurised. In addition, pressurisation reduces the amount of water needed and also the energy needed to heat the water, thus saving costs and benefiting the environment.

[0035] A small volume of water is then extracted from the kier 2 using the fluid outlet 4. This is mixed with a dye or dyes to produce the dye liquor. The liquor is then injected into the kier using the syringe 3 of the dosing system. The syringe 3 allows the injection rate, which affects how evenly the sample package is dyed, to be carefully and precisely controlled. Then, the main dyeing cycle begins, with the dye liquor circulation system performing a program of inside-to-out and outside-to-in flow directions, under control of the controller 5.

[0036] During operation of the machine, a series of heating and cooling stages are used. Heating is provided by the electrical heating element 8, and cooling is provided by the cooling jacket 12, which is preferably a high efficiency cooling jacket. The heating element 8 and the cooling jacket 12 can operate together to regulate the temperature. This is important because temperature affects the result of the dyeing process. In contrast, a production package dyeing machine typically includes a heat exchanger for temperature control of the dye liquor. This is a bulky piece of equipment, so is undesirable for use in a small sample package dyeing machine. Also, its size means that it takes up a significant liquor volume and hence increases the liquor ratio. This makes it further undesirable for a sample package dyeing machine, in which it is desired to replicate a production liquor ratio on a greatly reduced scale. Further, production machine heat exchangers generally operate using steam. Facilities for steam production are not readily available in sample laboratories, making a heat exchanger further unsuitable for sample dyeing. The present invention proposes to address these drawbacks by replacing the heat exchanger with an electrical heating element and a cooling jacket, which have been found to be much more suitable for a small scale operation. They are much more compact and keep the liquor ratio down, but nonetheless provide effective heating and cooling.

[0037] Towards the end of the dyeing cycle, a small sample of liquor is extracted from the kier using the fluid outlet 4. This is tested to determine the concentration of dye remaining in the liquor. When the concentration has dropped to a certain level, the dyeing process is determined to be complete, with the desired amount of dye having been taken up by the yarn package.

[0038] After the dyeing process, and any subsequent rinsing of the yarn with circulating water, the pressure is released, the fluid drained, and the sample package 9 then removed from the kier 2 by opening the cover 1 and releasing the locking cap 11.

[0039] The provision of an electronic controller to automate the dyeing process carried out by the machine can reduce the number of personnel required to produce dyed samples. A number of sample dyeing machines can be programmed for automated operation in advance, and can operate simultaneously with little operator input.

[0040] Further in this regard, a machine according to the invention may comprise a single electronic controller and two or more kiers (with associated components as described above) so that one controller can produce a plurality of different dyed samples at the same time. This saves space and time when several samples are to be produced at once.

[0041] Figure 6 shows a simplified schematic representation of a sample package dyeing machine 20 according to this embodiment. Four kiers 2, each having a spindle, a dye liquor circulation system, etc., are connected to a controller 5 that is operable to control the operation of dyeing in each of the kiers 2. The kiers 2 and the controller 5 may all be mounted in/on a combined housing such as a suitably adapted version of the housing 22 shown in Figure 1.

[0042] As discussed above, it is important that the liquor ratio used for dyeing a sample package is as close as possible to that which will be used in the final production. For a small package, therefore, a correspondingly small volume of dye liquor is needed. A minimum amount of dye liquor is required for proper circulation in any given machine, so if it is desired to use a small volume, it is advantageous to reduce the operating volume of a machine. According to the present invention, it is proposed to address this point using a novel spindle design which uses a smaller volume of fluid.

[0043] As described with regard to Figures 4A and 4B, for inside-to-out and outside-to-in fluid flow through a yarn package, a spindle includes a central hollow passage surrounded by an exterior wall with perforations therein. Dye liquor enters the hollow passage and flows through the perforations to the yarn, and also passes through the yam and the perforations to the hollow passage. The hollow passage is filled with dye liquor during these flow processes. The hollow passage therefore contributes to the operating volume of the machine. According to an embodiment of the invention, it is proposed to reduce the operating volume, and hence allow a smaller amount of yarn to be dyed, by providing a spindle with a reduced volume hollow passage.

[0044] Figure 7 shows a cross-sectional side view through a spindle according to this embodiment. The spindle 7 comprises a central elongate body 30 in the form of a closed inner volume that is impermeable to the circulating dye liquor. An outer wall 32 surrounds the inner volume 30 and is spaced apart from the inner volume 30 so that an annular passage 36 is defined between the two parts. The outer wall 32 has a plurality of perforations or apertures 34 in it, to allow fluid to flow through the outer wall. The outer wall 32 has a diameter (or other width if not of circular cross-section) sized to receive a yarn package, in the usual manner. The annular passage 36 is open at the lower end of the spindle via a fluid inlet/outlet 38, and closed at the upper end of the spindle. In operation, the spindle is mounted inside a kier such that the fluid inlet/outlet 38 is connected to a dye liquor circulation system, and a yarn package (not shown) is slotted over the spindle 7 and secured in place. For inside-to-out flow, dye liquor is supplied by the dye liquor circulation system through the fluid inlet/outlet 38 and into the annular passage 36. The liquor then passes through the perforations 34 in the outer wall 32, through the yarn package, and into the main body of the kier. This flow is indicated by the arrows. Outside-to-in flow follows the reverse direction.

[0045] Thus, the amount of dye liquor needed to operate the machine using the spindle 7 of Figure 7 is reduced by the volume occupied by the closed volume 30. Conventionally, the closed body 30 would not be present, and dye liquor would fill the whole of the volume inside the outer wall 32. Thus, the operating volume of a package dyeing machine can be brought down using a spindle according to this embodiment, and the liquor ratio needed to dye a small weight of yarn is also reduced and can more readily be made to match the liquor ratio of a large production machine. Therefore, this embodiment of the invention is particularly well adapted for use with a sample package dyeing machine. However, spindles according to this embodiment may also be of use in a larger scale production package dyeing machine.

[0046] The present invention has been described with respect to the dyeing of packages of yarn. However, it is equally applicable to the dyeing of other yarn-like textiles materials that are handled as packages, such as thread and cord. Thus, the term "yarn" as used herein is to be understood to include all similar textiles which are made into packages for dyeing.

Claims

1. A dyeing machine (20) for dyeing a sample yarn package (9) comprising:

a kier (2);

a spindle (7) mounted within the kier for supporting a sample yarn package inside the kier; and

a dye liquor circulation system (25, 26, 27) operable to circulate dye liquor through a sample yarn package supported on the spindle;

wherein the kier and the spindle are configured to accommodate a single sample yarn package with a weight less than 1.2 kg, and the machine has an operating volume such that a single sample yam package weighing less than 1.2 kg can be dyed using a liquor ratio of substantially 1:6.

2. A dyeing machine according to claim 1, in which the dye liquor circulation system is operable to circulate dye liquor through the sample yarn in both an inside-to-out flow direction and an outside-to-in flow direction.

3. A dyeing machine according to claim 2, in which the dye liquor circulation system comprises a dual-directional flow pump (28) to produce the inside-to-out and outside-to-in flows.

4. A dyeing machine according to any preceding claim, in which the interior of the kier can be pressurised.

5. A dyeing machine according to claim 4, further comprising an airpad (6) operable to pressurise the interior of the kier.

6. A dyeing machine according to any preceding claim, in which the machine further comprises a fluid outlet (4) via which fluid can be extracted from the kier.

7. A dyeing machine according to claim 6, in which the fluid outlet comprises a needle valve (4).

8. A dyeing machine according to any preceding claim, in which the machine further comprises a fluid inlet (3) via which fluid can be introduced into the kier.

9. A dyeing machine according to claim 8, in which the fluid inlet comprises a syringe (3).

10. A dyeing machine according to any preceding claim, further comprising a cooling jacket (12) disposed around the kier.

11. A dyeing machine according to any preceding claim, further comprising an electrical heating element (8) inside the kier operable to heat fluid inside the kier.

12. A dyeing machine according to any preceding claim, in which the spindle comprises:

an inner closed volume (30) into which circulating dye liquor cannot penetrate; and

an outer wall 32 around which a yarn package can be mounted and through which circulating dye liquor can pass to and from the yarn package, the outer wall surrounding the inner closed volume to define an annular passage (36) around the inner closed volume, and the annular passage connected to the dye liquor circulation system.

13. A dyeing machine according to any preceding claim, further comprising an electronic controller (5) operable to provide automated control of a dyeing process carried out in the kier.

14. A dyeing machine according to claim 13, further comprising one or more additional kiers (2) with associated spindles (7) and dye liquor circulation systems (25), the electronic controller being further operable to provide individual automated control of dyeing processes carried out in each kier.

15. A spindle (7) for supporting a yarn package (9) inside a kier (2) of a dyeing machine (2), the spindle comprising:

an inner closed volume (30) into which circulating dye liquor cannot penetrate; and

an outer wall (32) around which a yarn package can be mounted and through which circulating dye liquor can pass to and from the yarn package, the outer wall surrounding the inner closed volume to define an annular passage (36) around the inner closed volume, and the annular passage connectable to a dye liquor circulation system operable to circulate dye liquor through a yarn package supported on the spindle.

Drawing