TECHNICAL FIELD

The aspects and embodiments thereof relate to the field of supercritical CO2 dyeing systems.

BACKGROUND

Dyeing of textile fabric can be done in various ways. One such way is using a supercritical CO2 (carbon dioxide) dyeing system, in which supercritical CO2 is used as a solvent for dye. Supercritical CO2 is generally understood as CO2 above a temperature of 31 degrees Celsius and a pressure above 74 atm. Above these thresholds, the CO2 has behavioural properties between a gas and a liquid. The required temperature and pressure can be readily achieved using commercially available equipment.

Using CO2 as a dyeing solvent instead of water avoids the need for water intake and purification. Supercritical CO2 dyeing can also have additional advantages, for example economic advantages, as the energy required in the dyeing process may be lower than the energy required in conventional dyeing techniques. Furthermore, using supercritical CO2 may provide for a relatively short dyeing time compared to conventional dyeing techniques.

A conventional supercritical CO2 dyeing system can comprise a pressure vessel with an internal volume for holding supercritical CO2 and dye. A main dyeing beam can be positioned in the pressure vessel. The main dyeing beam can have a main dyeing beam body which can have a main passage, for example by having a hollow inside. In addition, the main dyeing beam body can have circumferential passages, for example through-holes, that are in fluid communication with the main passage. Supercritical CO2 and dye held in the pressure vessel can be pumped, using a circulation pump, into the main passage via a fluid inlet. After the supercritical CO2 and dye are pumped into the main passage, the supercritical CO2 and dye flow through the circumferential passages.

In order to dye fabric, the fabric is wound on the main dyeing beam body. In the above described system and fluid flow process, the supercritical CO2 and dye will pass through the fabric via the circumferential passages, resulting in dyeing of said fabric.

SUMMARY

A downside of known supercritical CO2 dyeing systems is that they are only suitable for dyeing large pieces of fabric, for example with a width of 40-80 inch. Yarn cannot be dyed using conventional CO2 dyeing systems as the size of the main dyeing beam body is too large. As a result, a different dyeing system is required for dyeing of yarn.

It is an object to provide an improved supercritical CO2 dyeing system, which preferably is capable of both dyeing pieces of fabric and spools of yarn.

A first aspect provides a supercritical CO2 dyeing system, comprising a pressure vessel with an internal volume therein for holding supercritical CO2 and dye, and a main dyeing beam positioned inside the pressure vessel. The main dyeing beam comprises a main dyeing beam body with a main passage and a fluid inlet into main passage therein, and a plurality of circumferential passages through the main dyeing beam body. The passages are in fluid communication with the main passage. The system further comprises an auxiliary dyeing member, comprising a first auxiliary dyeing beam. The first auxiliary dyeing beam comprises an auxiliary dyeing beam body with an auxiliary passage therein, and a plurality of circumferential passages through the auxiliary dyeing beam body. The passages are in fluid communication with the auxiliary passage. The auxiliary dyeing beam is mounted to the main dyeing beam such that a flow path for supercritical CO2 is provided between the main passage and the plurality of circumferential passages of the auxiliary dyeing beam via the auxiliary passage, and the auxiliary dyeing beam body is oriented at an angle relative to the main dyeing beam body.

The auxiliary dyeing beam may be permanently fixed to the main dyeing beam, or may even be integrally formed with the main dyeing beam. Alternatively, the auxiliary dyeing beam may be releasable mounted to the main dyeing beam. By virtue of the releasable mounting, the main dyeing beam may be selectively used for dyeing fabric or yarn, wherein the yarn is to be supported by the auxiliary dyeing beam.

In general, in the present disclosure, wherever supercritical CO2 is mentioned, the supercritical CO2 may be essentially free of dye, or the supercritical CO2 may have dye dissolved or suspended therein.

By providing one or more auxiliary dyeing members, it may become possible to use the main dyeing beam for dyeing yarn, within the conventional supercritical CO2 dyeing machine. Additionally or alternatively, the one or more auxiliary dyeing members may allow for a higher filling factor of the internal volume of the pressure vessel. The filling factor may be indicative of the volume of yarn which can be dyed in a single dyeing run.

An auxiliary dyeing member comprises an auxiliary dyeing beam body with an auxiliary passage. Such a passage can be a hollow inside of the auxiliary dyeing beam body. By having circumferential passages in the auxiliary dyeing beam body, that are in fluid communication with the auxiliary passage, any liquid, gas, and/or dissolved substance present in the auxiliary passage may flow through the auxiliary dyeing beam body. This can be done, for example, using through-holes or channels.

By having the auxiliary dyeing beam mounted to the main dyeing beam such that a flow path is available between the main passage of the main dyeing beam and the auxiliary passage of the auxiliary dyeing beam, it can be achieved that any fluid provided to the main passage, can also be provided to the auxiliary passage and therefore to the circumferential passages of the auxiliary dyeing beam. More specifically, when the supercritical CO2 and dye is provided to the main dyeing beam, for example using a pumping system, the supercritical CO2 and dye can be used to dye yarn wound on a spool mounted onto the auxiliary dyeing beam.

When the auxiliary dyeing beam body is oriented at an angle relative to the main dyeing beam body multiple auxiliary dyeing members may be positioned closer to each other. This can allow for mounting additional spools of yarn for simultaneous processing. The angle between the auxiliary dyeing beam body and the main dyeing beam body may for example be between 10 and 170 degrees, preferably between 60 and 120 degrees, and most preferably approximately or exactly 90 degrees.

When the auxiliary dyeing beam can be releasably mounted to the main dyeing beam, it can be achieved that the supercritical CO2 dyeing system can be converted between a conventional state in which fabric is mounted or wound onto the main dyeing beam, to a new state in which yarn on a spool can be dyed which is mounted onto the auxiliary dyeing beam. In this way, it may be achieved that switching is possible between yarn and fabric with a single dyeing system, allowing for an economic efficient way of dyeing a large range of textiles.

In embodiments, the auxiliary dyeing member may further comprise a mounting body releasably mounted on the main dyeing beam, and the first auxiliary dyeing beam may be mounted on the mounting body. By using a mounting body to facilitate the releasable mounting of the auxiliary dyeing member to the main dyeing beam body, the mounting body can be modified to fit the main dyeing beam of various supercritical CO2 dyeing systems or a specific supercritical CO2 dyeing system. For example, the mounting body can be dimensioned according to the particular shape of a particular main dyeing beam body. In addition, a mounting body may be used to cover circumferential passages of the main dyeing beam. This can result in better flow of supercritical CO2 and dye towards the auxiliary dyeing beam member.

As a further option, the mounting body can comprise at least one through-hole, and the at least one through-hole may be positioned between the auxiliary passage and at least one circumferential passage through the main dyeing beam body. Having a through-hole positioned between the at least one circumferential passage of the main dyeing beam body and the passage of the first auxiliary dyeing beam can result in an efficient way of pumping the supercritical CO2 and dye to the passage of the first auxiliary dyeing beam. More specifically, by aligning the at least one through hole with the passage of the auxiliary dyeing member, a fluid path is created for the CO2 and dye towards the spool of yarn.

The through-hole through the mounting body may have a flow through area which is larger than a flow through area of the at least one circumferential passage of the main dyeing beam body. This may allow for more convenient alignment of the mounting body through-hole and the at least one circumferential passage, which may require less accuracy. Alternatively, the flow through area of the through-hole through the mounting body may substantially correspond to the flow through area of the at least one circumferential passage of the main dyeing beam body.

As an even further option, the auxiliary dyeing member can further comprise a second auxiliary dyeing beam. The second auxiliary dyeing beam can comprise a second auxiliary dyeing beam body with a second auxiliary passage therein, and a plurality of circumferential passages through the second auxiliary dyeing beam body. The circumferential passages are in fluid communication with the second auxiliary passage, and the second auxiliary dyeing beam is mounted on the mounting body. Providing a second auxiliary dyeing beam, which may be comparable and similarly sized to the first auxiliary dyeing beam, can allow for mounting more spools of fabric or yarn in the supercritical CO2 dyeing system. As a result, it can be possible to dye multiple spools of fabric or yarn at the same time.

It shall be clear to the person skilled in the arts that any number of auxiliary dyeing beams can be comprised by an auxiliary dyeing member and can be optionally mounted to the mounting body. For example, three, four, five or even more auxiliary dyeing beams may be comprised by a single auxiliary dyeing member.

In further embodiments, all flow paths for supercritical CO2 between the fluid inlet of the main dyeing beam through the main passage back into the internal volume pass through a circumferential passage of an auxiliary dyeing member. As such, leakage of supercritical CO2 through the main dyeing beam may be prevented. Leakage here may imply supercritical CO2 which passes through the main dyeing beam back into the internal volume without passing through yarn or cloth.

As an option, the first auxiliary dyeing beam is substantially cylindrical- shaped. Having a substantially cylindrically shaped dyeing beam can allow for easier mounting of a spool of yarn on the auxiliary dyeing beam. More specifically, having a cylindrical- shaped dyeing beam can enable the mounting of conventional spools of yarn, which can be cylindrically shaped as well.

A length of yarn may be wound onto the first auxiliary dyeing beam. Yarn, or a piece of fabric, can be wound directly on the auxiliary dyeing beam or indirectly, for example by winding the yarn or fabric on a spool. Such a spool may be a perforated spool, with perforations which allow passage of supercritical CO2 there through.

A second aspect provides an auxiliary dyeing member which can comprise a first auxiliary dyeing beam. The first auxiliary dyeing beam can comprise an auxiliary dyeing beam body with an auxiliary passage therein, and plurality of circumferential passages through the auxiliary dyeing beam body. The passages can be in fluid communication with the auxiliary passage. The auxiliary dyeing beam can be arranged to be releasably mounted to a main dyeing beam of a supercritical CO2 dyeing system, preferably a supercritical CO2 dyeing system as described above.

An auxiliary dyeing member according to the second aspect may be particularly suitable for use in a system according to the first aspect. Options disclosed in conjunction with the first aspect and related to the auxiliary dyeing member may be readily applied to an auxiliary dyeing member according to the second aspect.

A mounting body may be arranged to be releasably mounted on a main dyeing beam of a supercritical CO2 dyeing system, wherein the first auxiliary dyeing beam can be mounted to the mounting body at an end of the first auxiliary dyeing beam.

In a further embodiment, the mounting body can comprise at least one through-hole, and this at least one through-hole is in fluid communication with the auxiliary passage of the auxiliary dyeing beam body.

In an even further embodiment, the auxiliary dyeing member can further comprise a second auxiliary dyeing beam. The second auxiliary dyeing beam can comprise an auxiliary dyeing beam body with an auxiliary passage therein, and a plurality of circumferential passages through the auxiliary dyeing beam body. The passages are in fluid communication with the auxiliary passage. The second auxiliary dyeing beam can be mounted to the mounting body at an end of the second auxiliary dyeing beam.

In general, an auxiliary dyeing member may be clamped, glued, welded, screwed, bolted, or otherwise connected to the mounting body.

As an option, the mounting body may comprise two parts and a hinging element arranged such that the two parts are hingable relative to each other. By virtue of the hinging connecting between the two parts, it can be convenient for a user to clamp the auxiliary dyeing member on the main dyeing beam body. For example, the hingable parts can form a full circle or closed inner perimeter when closed. The mounting body may be hinged between an open position and a closed position. In the closed position, the parts can be attached to each other by, for example, bolts or any other releasable connecting means.

As a further option, the mounting body can comprise two parts which are releasably connectable parts. This option may provide the advantage that it further allows for the user to mount the auxiliary dyeing beam on the main dyeing beam body.

A spool of yarn can be axially mounted over the auxiliary dyeing beam body. The axial direction may in general correspond to an elongation direction of the auxiliary dyeing beam body. The yarn may have been wound onto a perforated spool, which perforated spool is mounted over the auxiliary dyeing beam body.

In use, one or more closing members may be mounted onto the main dyeing beam body. A closing member is arranged for sealing off one or more circumferential passages through the main dyeing beam body. In use, not all circumferential passages through the main dyeing beam body may be used for dyeing spools of yarn. By using one or more closing members, undesired leakage of CO2 through one or more circumferential passages through the main dyeing beam body may be prevented for those circumferential passages around which no auxiliary dyeing beam is mounted.

A third aspect provides a method of dyeing at least two spools of yarn using dye dissolved in supercritical CO2. The method comprises the steps of mounting an auxiliary dyeing member, preferably an auxiliary dyeing member according to the second aspect, to a main dyeing beam body of a main dyeing beam of a supercritical CO2 dyeing system, preferably a system according to the first aspect. The method further comprises winding a first length of yarn on a first spool, winding a second length of yarn on a second spool, axially mounting the first spool of yarn over an auxiliary dyeing beam body of a first auxiliary dyeing beam, axially mounting the second spool of yarn over a second auxiliary dyeing beam body of a second auxiliary dyeing beam, dyeing the first and second lengths of yarn by transporting the dye dissolved in the supercritical CO2 first through the main dyeing beam, subsequently through the first or second auxiliary dyeing beam, and after that through or past the first or second spool of yarn.

In an embodiment of the invention, the method can further comprise the steps of mounting or winding a length of fabric over the main dyeing beam body, dyeing the length of fabric by transporting the dye first through the main dyeing beam, subsequently through circumferential passages in the main dyeing beam body, and after that through or past the length of fabric, and removing the length of fabric from the main dyeing beam body, wherein the length of fabric is dyed prior to or after the dyeing of the first and second spools of yarn.

BRIEF DESCRIPTION OF THE FIGURES

The aspects will be further elucidated on the basis of the exemplary embodiments that are represented in the figures. In the figures:

Fig. 1 shows in a schematic cross-sectional side view an example of a supercritical CO2 dyeing system and an auxiliary dyeing member attached thereon;

Fig. 2 A shows in a schematic cross-sectional side view an example of a super critical CO2 dyeing system and another embodiment of an auxiliary dyeing member attached thereon;

Fig. 2B shows a schematic cross-sectional view along the A- A line of Fig. 2A showing the supercritical CO2 dyeing system and the auxiliary dyeing members attached thereon;

Fig. 3 A shows in a schematic cross-sectional side view another example of a super critical CO2 dyeing system;

Fig. 3B shows in a schematic cross-sectional side view an even further example of a super critical CO2 dyeing system; and Fig. 4 shows an exploded view of an embodiment of an auxiliary dyeing member.

DETAILED DESCRIPTION

Figure 1 shows a schematic cross-sectional side view of a supercritical CO2 dyeing system 100. The dyeing system 100 comprises a pressure vessel 102, a main dyeing beam 106 and an auxiliary dyeing member 200. The pressure vessel 102 comprises an internal volume 104 for holding supercritical CO2. Such a pressure vessel 102 can be a conventional pressure vessel for super critical CO2 dyeing. This can require the vessel to be arranged for holding supercritical CO2 in the internal volume having a temperature of at least 31 degree Celsius and a pressure of at least 74 bar(g) essentially without leaking to the surrounding. The pressure vessel 102 may be provided with a door or hatch (not shown) allowing access into the internal volume 104, for example for moving the main dyeing beam 106 in and out of the internal volume 104.

The person skilled in the art will understand that supercritical CO2 dyeing systems may further comprise a dye dosing space and a heat exchange space.

A main dyeing beam 106 can be positioned inside the pressure vessel 102, inside the internal volume 104. Such a main dyeing beam 106 can be a conventional dyeing beam used for super critical CO2 dyeing of lengths of fabric. The main dyeing beam 106 comprises a main dyeing beam body 108. Said main dyeing beam body 108 can be cylindrically shaped and arranged to hold fabric removably wound around the main dyeing beam body 108.

The main dyeing beam body 108 comprises a main passage 110, for example embodied as a hollow chamber inside of the main dyeing beam body 108. In addition, the main dyeing beam body 108 comprises a plurality of circumferential passages 114, the passages 114 being in fluid communication with the main passage 110. The main dyeing beam body 108 furthermore comprises a fluid inlet 111, arranged to allow fluids such as supercritical CO2 with dye dissolved therein to enter the main passage 110. The circumferential passages 114 are substantially radially oriented, whereas the main dyeing beam body 108 is substantially axially oriented.

The super critical dyeing system 100 depicted in Fig. 1 further comprises an embodiment of an auxiliary dyeing member 200. The auxiliary dyeing member 200 is releasably mounted to the main dyeing beam 106. For example, when the auxiliary dyeing member 200 is mounted to the main dyeing beam 106, the auxiliary dyeing member 200 extends under an angle outwards from the main dyeing beam body 108.

The angle between the auxiliary dyeing member 200 and the main dyeing beam 106 is in the embodiment of Fig. 1 approximately 90 degrees. Such an angle may allow for multiple auxiliary dyeing member 200 to be mounted adjacent to each other on the same main dyeing beam 106.

The auxiliary dyeing member 200 depicted in Fig. 1 comprises a first auxiliary dyeing beam 202. Said first auxiliary dyeing beam 202 comprises an auxiliary dyeing beam body 203 with an auxiliary passage 204 therein. The auxiliary passage 204 can for example be a hollow chamber inside of the auxiliary dyeing beam body 203. Furthermore, the auxiliary dyeing member 200 comprise a plurality of circumferential passages 206 through the auxiliary dyeing beam body 203.

The circumferential passages 206 are in fluid communication with the auxiliary passage 204. The auxiliary dyeing member 200 is releasably mounted to the main dyeing beam 106.

A pump 107 is provided for circulating fluid in the internal volume 104. In particular, the pump 107 may be used to draw fluid from the internal volume 104, and supply this fluid to the fluid inlet 111 of the main dyeing beam 106. In general, the pump 107 may be positioned inside the pressure vessel 102, in particular inside the internal volume 104. Alternatively, parts of or the entire pump 107 may be positioned outside the pressure vessel 102. Figure 2A shows in a schematic cross-sectional side view another example of a super critical CO2 dyeing system 100 and another embodiment of an auxiliary dyeing member 200 attached thereon. More specifically, the auxiliary dyeing member 200 further comprises a second auxiliary dyeing beam 202’. The second auxiliary dyeing beam is similar to the first auxiliary dyeing beam, but may in other embodiments be differently shaped than the first auxiliary dyeing beam.

More specifically, the second auxiliary dyeing beam 202’ comprises an auxiliary dyeing beam body 203 with an auxiliary passage 204 therein. Furthermore, the second auxiliary dyeing beam 202’ comprises a plurality of circumferential passages 206 through the auxiliary dyeing beam body 202. The passage 206 are in fluid communication with the auxiliary passage 204. The auxiliary dyeing beam 202’ is mounted on the mounting body 208. Having multiple auxiliary dyeing beams 202, 202’ attached to the main dyeing beam body 108 via the mounting body 208 allows for the processing of multiple spools of yarn at the same time. For conciseness of clarity of Fig. 2A, not all components of the second auxiliary dyeing beam are provided with a reference numeral in Fig. 2A.

Figure 2B shows a schematic cross-sectional view along the A- A’ line of Fig. 2A showing the supercritical CO2 dyeing system 100 and the auxiliary dyeing beams 202, 202’ attached thereon.

The auxiliary dyeing member 200 further comprises a mounting body 208 releasably mounted on the main dyeing beam 106. The first auxiliary dyeing beam 202 and the second auxiliary dyeing beam 202’ are mounted on the mounting body 208. The mounting body 208 is a ring-shaped clamp, arranged to be liquid-tightly mounted to the mounting body 208.

The mounting body 208 comprises at least one through-hole 210, said at least one through-hole 210 being positioned between the first auxiliary passage 204 and at least one circumferential passage 114 through the main dyeing beam body 108. Such a through hole 210 allows for a fluid path between the main passage 110 and the auxiliary passage 204 via the mounting body 208. The embodiment of the mounting body 208 shown in Fig. 2B comprises two through-holes 210, one per auxiliary dyeing beam. In general, the number of through-holes 210 through the mounting body 208 may be equal to the number of auxiliary dyeing beams connected to the mounting body.

Figs. 3A and 3B schematically show in a section side view one embodiment of a supercritical CO2 dyeing system 100, in two different situations. In the first situation of Fig. 3A, multiple auxiliary dyeing member 200 are removably attached to the main dyeing beam 106. Wound or mounted onto the auxiliary dyeing members are lengths of yarn 300. The yarn is in general shown with a grid hatching. Part of a flow path for dye dissolved in supercritical CO2 is shown as a dash-dot-dotted line 302. Over the flow path 302, dissolved dye can be circulated by the pump 107. The flow path 302 passes through the inlet 111, the main passage 110 of the main dyeing beam body 108, through a circumferential passage 114 of the main dyeing beam body, through the optional mounting body of an auxiliary dyeing beam, and via an auxiliary passage and circumferential passage of said auxiliary dyeing beam past or through the yarn.

In the situation of Fig. 3B, a length of fabric 304 is dyed using the supercritical CO2 dyeing system 100. Compared to the situation of Fig. 3A, the main dyeing beam 106 now has no auxiliary dyeing members connected thereto. The conventional method of dyeing fabric may now be applied using the system 100.

Fig. 4 shows a partially exploded view of an embodiment of an auxiliary dyeing member 200. In the example, the auxiliary dyeing member 200 comprises four auxiliary dyeing beams 202, 202’, 202”, 202’”. The auxiliary dyeing beams are substantially radially equally spaced on the surface of a mounting body 208. The mounting body 208, in this example, is a ring-shaped clamp, that can be fixated using screws or bolts. As a particular option shown in Fig. 4, the mounting body comprises two parts 208, 208’, which are hingedly connected to each other. In general, the hinging connection may be arranged virtue of a separate hinge mechanism. Alternatively, part of the mounting body may form a living hinge or integral hinge, with the two parts 208, 208’ on different sides of the living hinge or integral hinge.

Removing said screws or bolts allows for the mounting body 208 to be opened, thereby allowing for the removal or mounting of the auxiliary dyeing member 200 from a main dyeing body 108. Through-holes 210 are provided in the mounting body 208, allowing for a fluid path through the mounting body 208 into an auxiliary passage of each of the auxiliary dyeing beams 202, 202’, 202”, 202’”.

In order to facilitate the mounting of a spool of yarn on the auxiliary dyeing beams 202, 202’, 202”, 202’”, the auxiliary dyeing beams are substantially cylindrical-shaped. Furthermore, a guard 402 can be provided at the base of the auxiliary dyeing beams to support the spool of yarn when mounted on the dyeing beam and/or to centre the spool relative to the auxiliary dyeing beam. An example of a perforated spool 300 is also depicted in Fig. 4, without the yarn wound onto it.

As a further option, a restriction cap 404 is provided at an end of the auxiliary dyeing beam 200, for example on the opposite end of the optional guard 402. The restriction cap 404 is removably attached to its respective auxiliary dyeing beam. When attached, and when a spool 300 of yarn is mounted on the auxiliary dyeing beam 200, the cap 404 is arranged to prevent or reduce movement of the spool of yarn in an axial direction relative to the corresponding auxiliary dyeing beam 200.

As an even further option, Fig. 4 shown an end cap 205 which may be used for sealing of an end of the auxiliary beam body 203, to prevent or reduce leakage of supercritical CO2 through the end 207 of the auxiliary beam body 203. It is to be noted that the figures are only schematic representations of embodiments and are given by way of non-limiting examples. For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that combination of all or some of the features described are also envisioned.

In the description above, it will be understood that when an element is referred to as being connect to another element, the element is either directly connected to the other element, or intervening elements may also be present. Also, it will be understood that the values given in the description above, are given by way of example and that other values may be possible and/or may be strived for.

It is to be noted that the figures are only schematic representations of embodiments that are given by way of non-limiting examples. For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the disclosure may include embodiments having combinations of all or some of the features described.

The word ‘comprising’ does not exclude the presence of other features or steps. Furthermore, the words 'a' and 'an' shall not be construed as limited to 'only one', but instead are used to mean 'at least one', and do not exclude a plurality.

In summary, an auxiliary dyeing beam is provided which can be mounted onto a main dyeing beam of a supercritical CO2 dyeing system. When the dimensions of the auxiliary dyeing beam are different from the dimensions of the main dyeing beam, different types of fabric- or yarn-like products can be dyed using a dyeing system designed for the dimensions of the main dyeing beam. The auxiliary dyeing beams may be mounted radially relative to the main dyeing beam.