The present disclosure concerns a system for processing textiles with ozone gas, and a related method. The present disclosure also concerns the textiles that are processed, i.e. treated, using the aforementioned system or method. In a non-limiting example, the textiles are garments.
Treating textiles, such as garments, with ozone gas is known. Patent document EP3670737A1 describes processing wool garments with ozone gas in a tumbler for inhibiting the garments' subsequent felting and shrinkage, and it also describes that said garments are wetted to a particular water to garment concentration by weight. More generally, the treatment of the textiles with ozone gas can be used for achieving a number of different finishing effects on the textiles, such as for example bleaching (i.e. changing the color of) the textile's fabric. In the art of treating textiles with ozone gas, an important objective is avoiding the creation of unwanted defects, such as color inhomogeneities, on the textile's surface during the ozone treatment. Moreover, another main objective is to increase the production capacity of the used systems and methods e.g. increase the amount of garments that a system (i.e. machine, apparatus) can process per batch. It is particularly challenging to simultaneously achieve the aforementioned two objectives because when attempting to increase the production capacity using what is previously known in the art, e.g. by placing a large batch of garments in a drum of an apparatus for processing textiles with ozone, then the ozone treatment may cause the creation of color inhomogeneities on the garments. These inhomogeneities may not appear if the same apparatus is used for treating a smaller batch. Hence, there are needed systems and a methods for controllably treating textiles with ozone, and which allow for treating large batches of textiles while avoiding the creation of defects on the garments.
The present invention allows for controllably treating textiles with ozone while avoiding or preventing the creation of defects, such as color inhomogeneities (e.g. stains), on the surface of the textiles. Importantly, the present invention allows avoiding said defects regardless of whether the batch of the treated textiles comprises a few or a lot of textiles. The present invention works particularly well for providing efficiently and with a high degree of reproducibility various different finishing effects on the textiles, and in particular for providing a balanced and homogenous bleaching of textiles, preventing the textile's undesired staining and uneven color distribution during the bleaching process. The optimized and high-quality processing that is provided with the present invention, can advantageously permit reducing the time, chemicals, energy and costs related to processing the textiles.
The present invention in its first aspect concerns a system for processing textiles, the system comprising: a machine for processing textiles (i.e. a textile processing machine), said machine being configured to treat, within the same, textiles with a gaseous mixture comprising ozone gas; and a dehumidification system which is connected to or is integrated into (or with) the textile processing machine. The dehumidification system is configured to reduce a humidity of the gaseous mixture. By reducing the humidity of the gaseous mixture, the dehumidification system can in effect control the humidity of the gaseous mixture. Surprisingly, the use of said dehumidification system for reducing or controlling the humidity of the gaseous mixture with which the textiles are treated, can achieve avoiding the creation of defects on the textiles, even when the apparatus processes a lot of said textiles per batch. The gaseous mixture can comprise a variety of different gases such as oxygen or nitrogen, but in a simple yet preferred embodiment, said mixture comprises atmospheric air mixed with ozone gas. Such a gaseous mixture can for example be created when in a part of the textile processing machine which originally contains the textiles and normal atmospheric air, there is introduced ozone which becomes mixed with said air. The gaseous mixture may also comprise water vapors which are released from the textiles before or during the textile's processing with ozone. The system of the first aspect of the invention, may be a machine or an apparatus for treating the textiles.
For the purpose of attempting explaining the beneficial effect that the use of the aforementioned dehumidification system has on the treatment of the textiles when using the system of the first aspect of the invention, the inventors propose the following which should not be perceived as limiting in any way the scope of the herein claimed invention. The inventors propose that the use of the humification system may in effect prevent or inhibit the formation of droplets of water on the surface of the textiles or on parts of the system in which the textiles are treated. It is proposed that when said droplets are possibly formed and absorbed by, or simply contact, the textiles, they may change locally the humidity of the textile's surface, which may in turn change locally the reactivity of said surface with the ozone, and may lead to the formation of local defects. It is further proposed, that said droplets may be more easily formed when increasing the amount of the textiles being treated with ozone in a given physical space/volume, because often a typical byproduct of the reaction of ozone with textiles is water, and said water (water molecules) may act to increase the humidity of the gaseous atmosphere during the treatment process. Hence, the inventors contemplate that when treating a large batch of textiles, a relatively large amount of water and corresponding humidity may be released from the textiles, or may be produced by the reaction of the textiles' surface with the ozone gas, and hence, the use of the dehumidification system may advantageously act for eventually reducing the humidity of the gaseous atmosphere, keeping said humidity under control. Likewise, the inventors do not dismiss the possibility that the humidity of the gaseous mixture which contains the ozone may directly affect the reactivity of the ozone with different parts of the textiles' surface, or that said humidity may cause the formation of droplets of water on different points of the surface of the textiles. Therefore, it is contemplated that the use of the aforementioned dehumidification system for reducing the humidity of the gaseous mixture, may prevent or inhibit the formation of droplets of water on or close to the textiles, and/or may act for controlling the reactivity of the textiles with the ozone, for the purpose of preventing or inhibiting the creation of defects on the surface of the garments, even for large batches of garments.
In some embodiments of the first aspect of the invention, the dehumidification system comprises any of a dehumidifier compressor, a condenser, a desiccant dehumidifier, a membrane-based dehumidifier, or a combination thereof. Said dehumidification system may also be called dehumidification module.
In a preferred embodiment of a system according to the first aspect of the invention, the textile processing machine (i.e. the machine for processing textiles) further comprises a chamber and a drum in the chamber, and said drum is configured to receive the textiles to be processed by the system. There are known types of textile processing machines for industrial, and even for domestic use, which comprises chambers within which there are tumblers or drums for processing textiles. Some preferred embodiments of the machine or system according to the invention may externally look similar to said known systems, and/or may have similar types of a chamber and a drum. The skilled person may understand that said tumbler is preferably rotatable and used for tumbling the textiles or, more generally, for imparting a mechanical action on the textiles. The skilled person may also understand that the gas mixture containing the ozone, may be the gas mixture found in said chamber or more specifically found in said drum during the treatment of the textiles.
In a preferred embodiment, the textile processing machine according to the first aspect of the invention further comprises an ozone generator configured to produce and provide the ozone gas. Said generator may be part of the textile processing machine, or may be a separate module that is connected to the textile processing machine for providing to the latter the ozone gas or the gaseous mixture containing the ozone gas. There are known types of ozone gas generators for use by the textile industry, and typically generators of this type produce ozone from the oxygen of the atmosphere.
In a preferred embodiment according to the first aspect of the invention, the dehumidification system comprises a closed-circuit cooler configured to cool a zone via which the gaseous mixture passes in the dehumidification system, such that dew is produced in said zone. Hence, the operation of said closed-circuit cooler in the particular type of dehumidification system that has it, can result to the reduction of the moisture in the gaseous mixture passing though the dehumidification system. Said zone may be a tube, i.e. a conduit or gas line, via which the gaseous mixture passes. Moisture from the gaseous mixture may be condensed in said zone, and may preferably be collected or removed therefrom. Advantageously, dehumidification systems which comprise such a closed-circuit cooler are commercially available and particularly easy to integrate and use with the rest of the system.
Optionally and preferably, the dehumidification system comprises a condenser and a water discharge line. Said water discharge line comprises a discharge outlet and a gas anti-leakage system configured to discharge via the same liquid water (dew) formed at the condenser when the system is in operation. The aforementioned optional gas anti-leakage system is configured to prevent the escape of ozone to the environment via the water discharge line, when the system is in operation. More preferably the gas anti-leakage system comprises a syphon and/or two water discharge valves which are sequentially located along the water discharge line. The use of the aforementioned water discharge line can advantageously permit the continuous operation of the dehumidification system over prolonged periods of time during which a high volume of dew may be produced. Moreover, the gas anti-leakage system may advantageously contribute to the safeness of the system, because ozone is toxic and hence its leakage via the optional water discharge line preferably should be avoided.
In a preferred embodiment, the system according to the first aspect of the invention further comprises a filter which is configured to filter the gaseous mixture. In the particular embodiment, the dehumidification system is connected to the textile processing machine via the aforementioned filter. Therefore, in the particular embodiment the dehumidification system receives, via the filter, the gaseous mixture from the textile processing machine. Preferably the filter is a strainer filter or another type of mechanical filter. More generally, the filter preferably is configured for filtering out (i.e. removing) textile fibers or particles, such as dust, to prevent the contamination of the dehumidification system. In an embodiment, the filter is located at a gas line that connects the dehumidification system with the textile processing machine.
In a preferred embodiment, the system according to the first aspect of the invention further comprises a circulation pump which is configured to return to the textile processing machine the gaseous mixture the humidity of which is reduced by the dehumidification system during an operation of the system. Hence, in said preferred embodiment, the circulation pump takes gas from the textile processing machine, passes said gas through the dehumidification system for decreasing the moisture of the gas, and passes back to the textile processing machine the gas with the decreased (reduced) moisture.
In a preferred embodiment, the system according to the first aspect of the invention further comprises a programmable control unit which is configured to control the textile processing machine and/or the dehumidification system. More preferably, the programmable control unit is PLC-based. In an embodiment, the system comprises a control unit as described above, and further comprises an interface which is connected to the control unit. In the latter case the control unit may operationally be connected to the textile processing machine and/or the dehumidification via an electronic interface. The control unit itself may comprise such an interface. The use of the optional control unit may advantageously facilitate a highly automated use of the system of the first aspect of the invention, and in particular the execution of certain textile treatment recipes that may require accurately controlling the system.
It is known that the formation of dew, i.e. the formation of drops of water from the condensation of vapor of the gaseous mixture, depends not only on the humidity, but also on the temperature of the gaseous mixture. It is contemplated that the ozone treatment of the textiles may depend on a number of parameters such as the temperature and/or the humidity of the gaseous mixture with which the textiles are treated. Hence, it may be advantageous monitoring the temperature and/or the humidity of the gaseous mixture with which the textiles are treated within the system of the first aspect of the invention. For this purpose, in some preferred embodiments of the first aspect of the invention, the system for processing textiles further comprises one or more measurement units configured to measure the temperature and/or humidity of the gaseous mixture. These measurements units may optionally be used for providing a feedback for the operation of the dehumidification system, or for the operation of the textile treatment machine, or may optionally be used for simply monitoring the textile treatment process that is implemented using the system according to the invention. Such monitoring may be important for quality control purposes. It is noted that in a very preferred embodiment according to the first aspect of the invention, the system comprises a control unit as the one described further above, and also comprises one more measurement units. Moreover, in the aforementioned very preferred embodiment, the programmable control unit is operationally connected to the one or more measurement units, and the control unit is also configured to process temperature and/or humidity measurements made by the one or more measurement units during an operation of the system.
The present invention in a second aspect concerns a method for processing textiles, wherein the method comprises: in a machine for processing textiles, treating textiles with a gaseous mixture that comprises ozone gas; using a dehumidification system which is connected to, or is integrated into, the textile processing machine for reducing a humidity of the gaseous mixture. The machine for processing textiles can also be called textile processing machine, and may be the machine of the system of the first aspect of the invention. Also, the method of the second aspect of the invention can be implemented using the system of the first aspect of the invention.
In some preferred embodiments of the method of the second aspect of the invention, the textiles are garments, such as dyed garments, or jeans, or knits, or garments comprising denim or wool. The processing of these types of textiles at the industrial level often involves their treatment with ozone. Hence, the present invention may advantageously improve the processing of these types of garments in terms of yield, reproducibility and quality of the obtained product.
In a preferred embodiment of the method of the second aspect of the invention, the dehumidifier system reduces, i.e. lowers, the relative humidity of the gaseous atmosphere such that a condensation of the humidity in the textile processing machine is reduced or prevented. It may be understood that the dehumidifier system may reduce the gaseous mixture's relative humidity is so that the latter is or becomes less than 100%. Overall, it may be understood that most preferably the dehumidifier system is configured to control the gaseous mixture's relative humidity so that the latter is or becomes less than 100% when the dehumidifier system is in operation.
It may be understood that the method of the second aspect of the invention may optionally further comprise one or more additional textile processing steps. Some non-limiting examples of said additional steps are washing, drying, softening, abrading, processing using laser, or otherwise preparing, treating or finishing the textiles, or combinations thereof.
The present invention in another aspect concerns a textile obtained by the method of the second aspect of the invention. Hence, an aspect of the invention concerns a textile which has been treated using the method of the second aspect of the invention, or the system of the first aspect of the invention.
With reference to
A—Bleaching Process Machine (prior art)
B—Textile and Denim Product to be Bleached
C—Droplet
D—Bleached, Stained Textile and Denim Product
E—Bleached, Stainless and Homogeneous Appearance Textile and Denim Product
1. PSA Oxygen Concentrator
2. Ozone Generator
3. Ozone Reaction Machine, textile processing machine
4. Strainer Filter
5. Machine Output Temperature and Humidity Measurement Unit
6. Dehumidification Unit
7. Dehumidification Output Temperature and Humidity Measurement Unit
8. Circulation Pump
9. Ozone Gas Catalytic Disruptor
10. Ozone Gas Discharge Pump
11. Control Unit
12. Ozone Generator Water Cooler
13. Dehumidification Cooler
14. Condensed Water First (or Upper) Drain Valve
15. Condensed Water Second (or Lower) Drain Valve
16. Condensed Water Discharge Outlet
17. Compressed Dry Air Inlet
18. Oxygen Gas Line
19. Ozone Gas Line
20. Machine High Humidity Gas Output
21. Low Humidity Gas Return After Dehumidification
22. Machine Ozone Gas Discharge Outlet
23. Ozone Generator Cold Water Inlet Line
24. Ozone Generator Heated Water Outlet Line 20
25. Dehumidification System Cold Water Inlet Line
26. Dehumidification System Heated Water Outlet Line
27. Degraded Ozone Gas (Oxygen) Discharge Outlet
30. System for processing textiles
31. Textile processing machine, machine for textile processing
32. Drum, tumbler
33. Chamber
In the prior art there are known apparatuses, machines or systems which are suitable for bleaching textiles using ozone. A particular type of textiles of great interest to the industry are textiles dyed with indigo, and particularly denim garments or other types garments or textiles dyed with indigo. Ozone can be used for oxidizing the indigo dye molecules of a denim, thereby bleaching the denim, changing the color of the denim's surface. The oxidation of an indigo molecule by the latter's reaction with O3 (ozone) in the presence of a water may result to the release of additional water, and hence, to the increase of the overall humidity on or around the textile.
The inventors of the present invention noticed that when bleaching jeans or other types of denims using ozone in a known textile processing machine, there are droplets of water formed in the system's space where the denims are processed. The inventors further noticed that when the aforementioned droplets are formed, very often the surface of the bleached denims have unwanted spots due to excessive bleaching in said spots, as is schematically shown in
Referring to
3, the dehumidification unit 6 provides dew by lowering the humidity in the air (the gaseous mixture) at the high humidity gas outlet 20 and collects water droplets which are formed as a result of dew. The system 30 of
The system 30 of
The system 30 of
A preferred embodiment of the aforementioned method is implemented using the system of
An operation of the system of
The system 30 of
Said ozone generator water cooler 12 is a closed-circuit water-cooling system. Cooling is provided by circulating the cold water produced in the ozone generator water cooler 12 through the ozone generator 2 via the ozone generator cold water inlet line 23. The generated heated water is returned to the ozone generator water cooler 12 via the ozone generator heated water outlet line 24. The ozone gas produced in the ozone generator 2 is sent to the ozone reaction machine 3 via the ozone gas line 19. In the ozone reaction machine 3, indigo and reactive dyestuffs on high humidity and wet textiles and denim products may react chemically with ozone gas which, hence, bleaches the textiles by making the latter's colors. As a result of this chemical reaction, large amounts of water molecules may be formed. The inventors noticed that if the relative humidity of the environment rises above 100%, dew and dripping occur and cause staining on textile and denim products. In order to prevent this, the gas at the high humidity gas outlet 20 from the interior of the ozone reaction machine 3 is first passed through a strainer filter 4, and then the temperature and humidity are measured by the machine outlet temperature and humidity measurement unit 5. Humidity is reduced in the gaseous mixture passing through dehumidification unit 6, as a result of the formation of dew. Hence, water droplets are formed as a result of dew accumulated in the dehumidification unit 6. The accumulated condensed water is discharged from the condensed water discharge outlet 16 through the two valves 14, 15 which are the condensed water upper discharge valve 14 and the condensed water lower discharge valve 15.
The temperature and humidity of the air whose humidity is reduced in the dehumidification unit 6 are measured again in the dehumidification output 20 temperature and humidity measurement unit 7. After dehumidification, the ozone (the gaseous mixture comprising the ozone) is returned to the ozone reaction machine 3 via the low humidity gas return 21 and the circulation pump 8.
Regarding the operation of the embodiment of
Also, regarding the operation of the embodiment of
In view of the present invention, the inventors propose the following for explaining why there are spots in textile and denims processed with machines known in the prior art. With reference to
While preferred embodiments of the present invention concern the processing of textiles dyed with indigo, the present invention may also be used for the processing of textiles dyed with different dyes, or not dyed at all. Moreover, the method according to the present invention, may also comprise one more additional steps to the ones described further above. Non-limiting examples of such additional steps are wetting, drying, dyeing, washing, abrading, bleaching, wetting the textiles or otherwise preparing, processing or finishing the textiles.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.
Number | Date | Country | Kind |
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2022/000633 | Jan 2022 | TR | national |