Patent Application
20190194864
Aspects of this invention relate to providing moisture for ozonation processes applied to textile products, and of providing needed moisture by spray of micro water droplets with ultrasonic atomization or water nebulizer.
Instead of chemicals conventionally used in finishing processes in textile, selection of chemicals having lower environmental impacts and also optimization of processes is needed and studies have been carried out in this line.
Ozone gas is used in bleaching as well as bleacher and color bleacher in parts washing processes of garments made from denim in recent years as ozone gas is a very strong bleacher in addition to its bactericide and fungicide feature.
Being an oxidative agent and an active oxygen source, Ozone has become an alternative to potassium permanganate, hypochlorite and hydrogen peroxide in processes of bleaching cotton fabrics and products. Ozone has advantage over other bleaching chemicals in finishing processes due to its features of not releasing residuals, not damaging environment and being efficient even at low temperatures.
In textile processes where ozone is used, ozone generator can produce ozone from air, and ozone shows a strong oxidative feature and is efficient at low temperature, it may not require addition of auxiliary chemicals and may provide saving in heating costs just because it is highly efficient at cold temperatures.
Ozone gas is generally used in small scale of denim washing processes for removal of dye and cleaning pocket back staining for the purpose of used effect and creation of patterns in denim washing sector.
Successful color fading by ozone is subject to fulfilment of some conditions. Firstly, the textile should be wet so that ozone may react with the dyes of textile products. System is preferred to have a given level of moisture during process. In addition, ambient temperature is to be kept substantially constant for a repeatable finishing result in ozonation process.
The moisture required for ozonising textile products with current ozonation systems is provided by means of directly wetting the textile products and/or putting wet fabric parts other than textile products. However, wetting fabric completely in line with these methods causes swelling of yarns in the fabric. This effect enhances surface area of yarn on fabric surface and supports ozone diffusion while ozone movement capacity is restricted in deeper parts of the fabric. Therefore, penetration of ozone into fabric reduces and ozonation performance decreases.
The document numbered EP0554648B1 discloses decolorizing a textile material containing cellulosic material having warp yarn with use of ozone. Said garment is dyed with an ozone oxidizable dye, said garment is wetted and then said garment is contacted in a vapour phase with a mixture of steam and ozone at high temperatures for a selected period of time. Here steam represents inert gases. Upon contacting steam, ozone oxidizes said dye and the oxidation with the ozone is terminated prior to any substantial oxidation of the warp yarn of the cellulosic material. Moisture textile material needing for ozonizing under this patent certificate is provided by means of heating the textile material.
PCT application numbered WO2014113238 discloses use of a dry ozonising process to decolorize a dyed denim fabric. With use of ozone, the application aims to eliminate disadvantages caused by stone washing method and use of bleaching chemicals. General and/or local decolorizing is provided in denim fabrics by means of applying three different methods containing use of ozone. In the first method, denim fabric is wetted, excess amount of water is removed and the fabric is subjected to ozone for decolorizing. In the second method, water is sprayed on to the area of denim desired to be decolorized and the fabric is exposed to ozone. In the third method, denim textile product and wet cotton fabric craps are put into a drum together and all drum content is exposed to ozone. Said three methods can be applied separately as well as in a combination. In the application, the moisture needed for ozonizing is provided by wetting the main fabric and/or putting wetted cotton scraps together with main fabric into the drum. In this application, for decolorizing regionally on the fabric, it is sprayed onto desired area.
In one aspect, this disclosure can provide controlled moisture in the volume where ozonizing process is conducted for ozonation process in textile.
In another aspect, this disclosure describes methods and systems for providing moisture for the ozonation process as water in micro droplets form into the enclosed volume by means of ultrasonic atomizer or water nebulizer.
In another aspect, this disclosure describes methods and systems for performing ozonation process by use of less water through giving water to fabrics in micro droplets and infusing the atmosphere of the volume in which the textile is treated with the microdroplets.
In another aspect, this disclosure describes methods and systems that can prevent or reduce swelling and tightening of fabric threads such as fiber yarns during ozonation process by use of less amount of water. This enables ozone to pass through the fabric surface and penetrate farther into the fabric, as compared, for example, to methods in which the fabric is only wetted directly.
In another aspect, the methods and systems described herein form super oxide radicals by means of reaction of water micro droplets and O3, and thus generate molecules having efficiency higher than O3 effectiveness. Thus ozonation efficiency is enhanced by means of producing super oxide radicals which are more reactive than ozone.
In order to achieve the purpose(s) of the invention, the interaction with the dry fibres, of super oxide radicals generated as a result of reaction of ozone with ultrasonic atomized and micro water droplets providing moisture to ozonation system is shown in the figures attached and in the figures,
In accordance with this disclosure, water can be atomized or nebulized and provided in an atmosphere with generated ozone for treating textiles and fabrics.
Ultrasonic atomization devices having ultrasonic atomizer terminals can be used for this purpose. The difference of ultrasonic atomizer terminals from other spray terminals is that they can perform spraying in fine grains of fog at low speed. Instead of using pressure, vibrational forces are used to provide it.
The fluid is sprayed in fine fog form by use of high frequency of sound vibrations. Piezoelectric converters converts the electric input into mechanical energy in form of vibrations and this creates capillary waves in fluid film when sent to atomizing terminal. When vibration magnitude is increased, that capillary wave magnitude also reaches a certain critical high level. Waves become so high at this point that they cannot support their own structure and fine droplets start to fall from end of each wave in a manner to result in atomization, as illustrated in
Droplets generated by ultrasonic atomization have relatively low size dispersion. Average droplet size varies from 10 nanometres-100 micrometer subject to frequency of end of atomization where worked. The significant factors affecting size of the generated droplets are the viscosity of vibration, surface voltage and fluid viscosity. Frequencies generally vary between 20 kHz-2.5 MHz. This frequency range is outside the range hearable by humans. In addition, high frequencies generate the lowest droplet size.
In addition to an atomizer, a nebulizer can be used to create a mist with fine water droplets.
Much more active super-oxidizing radicals generate upon reaction of water with O3 under suitable conditions while water droplets still float in the air in addition to O3 oxidizing radicals reacting with wet fabric by this-method. Such suitable conditions are the proper temperature and humidity conditions specified under patent application numbered TR2017/22157, which is incorporated by reference herein. Oxidizing radicals generated in this way are not of very stable structure as chemicals. When they hit any oxidizable agent or when suitable conditions disappear, they may immediately deform or degrade and lose their effects.
Some of the generated super-oxidizing radicals are as follows.
H2O+O3→H2O2+O2
(Water H—O—H)+(Ozone O=O+—O−)→(Hydrogen peroxide HO—OH)+(Oxygen O=O)
H2O+O3→H2O4
(Water H—O—H)+(Ozone O=O+—O−)→(Tetraoxident HO—O—O—OH)
For instance, such super oxidizing radicals can be generated by adding O3 into water or wetting the fabric but it may easily deteriorate because of intensive hydrostatic and hydrodynamic structure of water or fabric fiber consisting of other oxidizable chemicals.
According to previously used wet fabric and O3 reaction methods, too strong oxidization reactions occur because of superoxidising radicals hitting the fabric surface. In addition, penetration (effect onto deeper part of yarn) of the superoxidizing radicals into dry fabric in micro water droplets (yams forming fabric) is much more than the penetration O3 into wet fabric fiber.
As shown in the
In this embodiment, the ozonation process of fabric occurs in the enclosed volume (5) machine, and moisture is provided with an ultrasonic atomized (UA). One embodiment of the enclosed volume machine is described below in connection with
In the related art, the fabric is oxidized by means of adding ozone into an enclosed volume (5) for bleaching colour of textile products. However, in order to ensure same darkness of the colour fading of the fabric, that is, to conduct ozonation process in a controlled manner, the moisture in the enclosed volume (5) can be maintained at required level. For achievement of this, water supply of micro droplet size is made to the container volume (5) of ozonation connected with an ultrasonic atomizer (UA). Water supply is provided by means of transmission of water to ultrasonic atomizer (UA) through liquid transmission system and supply of it to the enclosed volume (5) in micro droplets by spraying from ultrasonic atomizer. In addition, water (3) can be transferred separately as well as together with needed chemicals in the water. Subject to the rate of moisture required to be provided in ambience, the system can be persistently monitored and water of the needed quantity can be supplied to the system in micro droplets by means of the atomizer. As a result, upon bringing the supplied water (3) in micro droplets form, water and O3 go into reaction and form super oxide radicals. Super oxide radicals which are much more reactive when compared to ozone enhance ozonation efficiency.
Steps of moistening for ozonation process are preferably conducted as follows:
Aspects of the present invention provides conduct of process of ozonizing fabric inside the enclosed volume machine (10) at fixed ambient moisture and temperature. In any case, the moisture and temperature value inside the machine can be fixed by means of external intervention.
In the related art, the fabric is oxidized by means of adding ozone into an enclosed volume (10) for bleaching colour of textile products. However, in order to ensure same darkness of the colour fading of the fabric, that is, to conduct in a controlled manner, the moisture and temperature in the enclosed volume (10) must also be controllable. To provide it water addition and acclimatization is made to the machine by means of added mechanisms. The water addition can be made by means of flowing into the system through a pipe as well as by pulverizing through spraying or transferred into enclosed volume in micro dripping by means of water nebulizer or atomizer. In addition, water can be transferred separately as well as together with needed chemicals in the water. System is consistently monitored subject to moisture rate required to be provided in the ambience, water addition can be made when required. As a result, a controlled moistening is provided in a controlled enclosed volume (10) and moisture level is maintained.
Another significant parameter during ozonizing is the temperature value of the enclosed volume (10). To provide it again continuous acclimatizing is provided in the ambience. The air/ozone mixture absorbed from inside is passed through a heat exchanger (110) and cooled or heated and then re-supplied. The critical point here is to keep the inside of the machine (10) constant at preferred temperature without being influenced by ambient temperature.
A preferred embodiment of the invention, after the sent air is discharged, it is passed through a serpentine pipe type tunnel (heat exchanger (110) is heated or cooled and then supplied to the machine (10) again. Therefore, in this method the air coming from inside is brought to desired temperature level again and transferred into the machine (10).
The steps of the process are preferably conducted as follows:
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017/22157 | Dec 2017 | TR | national |
| 2018/03905 | Mar 2018 | TR | national |
