Ozone treatment of cellulosic artificial fiber fabrics

Abstract

The invention discloses a method for producing a dyed and finished artificial cellulose fiber fabric with clean, soft tactile finish, comprising subjecting the fabric to a wet process treatment using mechanical action and subjecting the fabric to a rolling treatment, characterized in that the fabric is additionally treated with ozone. Further, a fabric or garment finished using the method is disclosed, the fabric or garment having a clean soft touch finish.

Description

[0001] This invention relates to a method for dyeing and finishing fabrics or garments made of cellulosic synthetic fibers, particularly lyocell, modal, or viscose fibers.

[0002] In this specification, the terms “cellulose wood-based fiber fabric,” “lyocell fabric,” “modal fabric,” or “viscose fabric” refer to fabrics made from yarns, particularly staple yarns (but not limited to) comprising cellulose man-made fibers, lyocell fibers, modal fibers, or viscose fibers, especially woven or knitted fabrics.

[0003] Such yarns may contain only lyocell fibers, or only lyocell fibers blended with one or more other cellulosic fibers (such as cotton, viscose, linen) or non-cellulosic types (such as polyester, elastane, or nylon). Such yarns may also contain only modal fibers, or be blended with one or more other cellulosic fibers or non-cellulosic types (such as cotton, viscose, linen, polyester, elastane, or nylon). Furthermore, fabrics may additionally include yarns that do not contain lyocell, modal, or viscose fibers, such as yarns of the other fiber types mentioned above and their blends.

[0004] Lyocell fibers are produced through a process called solvent spinning, in which a cellulose solution is extruded through a spinneret into a coagulation bath. Therefore, they are alternatively referred to as solvent-spun cellulose fibers. This method is described in US-A-4,246,221 and uses an aqueous tertiary amine N-oxide (specifically N-methylmorpholine N-oxide) as a solvent. Thus, lyocell fibers differ from other man-made cellulose fibers, which are themselves produced by forming cellulose into a soluble chemical derivative, then extruding a solution of that derivative into a bath, regenerating the extrudate into cellulose fibers; such as viscose or modal fibers.

[0005] Modal fiber is a high wet modulus fiber produced using a modified version of the viscose process. In the viscose process, the fiber is produced by extruding a solution of cellulose derivatives through very small spinnerets, then changing the pH to precipitate the cellulose derivatives and converting them back into cellulose.

[0006] Cellulose in the form of wood pulp is commonly used as a starting material, although cellulose from other sources, such as bamboo, cotton linters, and cellulose materials obtained from recycling processes, is also used. The wood pulp is soaked in sodium hydroxide and then reacted with carbon disulfide to convert it into cellulose xanthate. The xanthate dissolves in the sodium hydroxide solution to produce a viscous, golden liquid, commonly known as viscose.

[0007] The viscose is degassed and filtered. It is then extruded through a precious metal spinneret into a spinning bath composed of sulfuric acid, sodium sulfate, and zinc sulfate. The acid reacts with the sodium hydroxide in the viscose, causing cellulose xanthate to precipitate. The acid also reacts with the cellulose xanthate, converting it back into cellulose.

[0008] While the newly formed fiber is still in a plastic state, it is stretched to increase the orientation of cellulose molecules along the fiber axis and promote crystallization. Then, depending on the design of the spinning machine and the desired product, the fiber can be cut to a certain length to form short fibers, or it can be kept as a continuous filament or tow.

[0009] In the remainder of the process, the fibers are washed to remove non-cellulose products from the reaction, such as sodium sulfate and hydrogen sulfide, then finished with lubricants and antistatic agents to aid downstream processing, and finally dried.

[0010] Modern adhesive manufacturing plants are designed to recover as many byproducts as possible from the process. This is crucial for avoiding environmental pollution and ensuring the safety of workers and surrounding communities. Better recycling and reuse of byproducts also brings positive economic benefits.

[0011] The Modal process is similar to the viscose process in most respects. The difference lies in the fact that Modal first uses a spinning bath composed of a lower concentration of acid and free of zinc sulfate for coagulation and stretching. The newly coagulated fibers, mainly composed of cellulose xanthates, are stretched up to three times their original length. This causes the cellulose xanthate molecules to align parallel to each other. Then, through further acid treatment, the cellulose xanthates are converted back into cellulose. Additives can also be mixed with the spinning solution to slow down the regeneration of cellulose during spinning. These additives, along with the modified spinning bath and viscose components, allow the fibers to be stretched to a greater extent than ordinary viscose fibers. This results in fibers with higher orientation, greater strength than viscose fibers, and a modulus closer to cotton.

[0012] Modal fiber is often blended with cotton to produce a softer fabric than fabrics made solely from cotton. Modal fiber is widely used in knitted fabrics for women's underwear and clothing. Existing technology

[0013] Lyocell fibers are known to be prone to fibrillation under relaxed wet abrasion conditions (such as during vigorous dyeing and finishing processes), and various methods have been proposed to address this phenomenon.

[0014] When it is desirable to avoid surface fibrillation, a relatively mild dyeing process is used, such as pad dyeing of flat fabrics, followed by resin finishing with a crosslinking agent on the dyed fabric to protect the fibers from fibrillation in subsequent washing processes.

[0015] Another approach to addressing this fibrillation tendency is to treat the fabric to remove the relatively long, protruding fiber ends formed in the first stage of the fibrillation process (the so-called "primary fibrillation"). These ends would otherwise create a noticeable gross hairy effect on the fabric surface, often resulting in tangling and thus ruining its appearance. On the other hand, the growth of shorter fibrils formed during the fibrillation process (the so-called "secondary fibrillation") is promoted. These shorter fibrils create a surface finish characterized by "cleanliness"—in a sense, essentially free of hairiness—and a soft touch imparted by the shorter fibrils on the surface; this touch is known as a "soft touch finish." When the shorter fibrils grow sufficiently, the soft touch of the fabric becomes even more pronounced, and this soft touch finish is known as a "peach touch finish."

[0016] WO-A-95 / 30043 describes one example of such a procedure and involves removing primary fibrillation products formed during the dyeing process by using an acid catalyst in conjunction with an optional crosslinking agent (such as N-hydroxymethyl resin). WO-A-97 / 30204 describes another example in which the Lyocell fabric is pretreated with an aqueous solution of an oxidant (such as sodium hypochlorite or hydrogen peroxide) at high temperature before dyeing. GB-A-2,314,568 describes yet another example and involves subjecting the Lyocell fabric to an extended treatment of 30 to 120 minutes with a strong inorganic acid (such as sulfuric acid) solution before rinsing using the dyeing machine itself (e.g., a jet dyeing machine), followed by the start of the dyeing process on the same machine. Each of these processes is difficult to control to produce consistent results, and none of them have yet been put into full-scale commercial operation.

[0017] One process successfully used in commercial processing involves post-treatment of Lyocell fabrics subjected to wet processing operations, such as dyeing. In this post-treatment, protruding ends resulting from primary fibrillation are removed by applying a cellulase solution to the fabric. WO-A-96 / 17994 discloses such a method. The desired secondary fibrillation is formed in subsequent processing, such as in the dyeing process itself (if the dyeing process is later) or by using a rotary drum machine in subsequent washing and drying steps to produce a soft-touch finish on the fabric surface.

[0018] Cellulase treatment successfully removes the long fiber ends generated during primary fibrillation from the fabric surface, but it is expensive in terms of both material cost and processing time.

[0019] To overcome these shortcomings, a process has been developed, and is described in WO-A-02 / 103104. This process includes pretreating the Lyocell fabric prior to conventional fibrillation-inducing steps such as dyeing (e.g., jet dyeing), washing, and drying, subjecting the fabric to vigorous action in at least one of those steps to induce fibrillation on the fabric surface; and the process also involves uniformly impregnating the fabric with an aqueous solution of an acid or acid donor prior to heat treatment in a gaseous atmosphere to activate the action of the acid or acid donor. The temperature range used for the heat treatment is 120-220°C, preferably 140-200°C. This process enables the production of dyed and finished Lyocell fabrics with a clean, soft-touch finish and virtually no visible creases.

[0020] Like many other fabrics, modal and viscose fabrics are prone to pilling during use and care. This is undesirable, and reducing the tendency of a fabric to pill can improve its attractiveness and practicality.

[0021] Pilling is a surface defect in textiles caused by abrasion and wear. Pilling is caused by the working loosening of the ends of fibers that make up the fabric. If one end of a fiber is caught in the fabric, the loose end tends to curl into an entangled ball. It may also combine with other loose fiber ends nearby to form a larger entangled ball. These fiber balls attached to the fabric surface are called fuzz balls, and their formation is called pilling.

[0022] Pilling occurs during washing and wearing of a fabric when loose fiber ends detach from the fabric surface. Then, abrasion of the fabric surface during washing and friction with other surfaces during wear cause the loose fiber ends to coil into small bundles, which are then held in place by fibers that still form part of the fabric. Pilling is generally considered to occur in four distinct stages: fuzz formation, entanglement, growth, and abrasion shedding.

[0023] All fabrics pill to some extent, with modal tending to pill slightly more than viscose. Pilling becomes a problem if the pills become large enough to be visible and still adhere to the fabric through fibers that are still embedded in the fabric structure. Pilling is influenced by the fabric's design and structure, the fibers used to make it, how it is processed during manufacturing, the wearer's behavior, and the environment in which it is used.

[0024] Stronger fibers are more likely to pill during use because the fibers that hold the pills in place are less likely to break, thus releasing the pills from the fabric surface. Fabrics made from synthetic fibers such as polyester, nylon, and acrylic tend to pill the most, but natural fiber fabrics such as wool and cotton also pill to some extent.

[0025] Fabrics made of shorter fibers are more prone to pilling because they have more fiber ends than fabrics made with longer fibers, and because shorter fibers are less firmly attached to the fabric, they are more likely to come loose. The more loose fibers in a fabric, the more likely it is to form pills.

[0026] Pilling can be prevented by preventing fibers from detaching from the fabric surface. This can be achieved by singeing the fabric surface to remove fiber ends protruding from the surface and by increasing the yarn twist to more firmly anchor the fibers to the fabric. Several proprietary finishing agents and chemical treatments are available that can prevent or reduce pilling. Polymer coatings can be used to bond fibers to the fabric surface and prevent fibers from tangling on the fabric surface. Weak points can sometimes form in the fibers, making it less likely that they will remain attached when pills do form. Fixing the fibers breaks at the weak points, thus releasing the pills. Cotton fabrics can be treated with cellulase to remove surface fibers, thereby preventing pilling.

[0027] Modal and viscose fabrics may pill during dyeing and finishing, as well as during subsequent wear and care of garments made from them. Pilling can be controlled using the methods described above. Using higher twist yarns and weaving or knitting tighter fabrics will reduce pilling. Anti-pilling finishing agents can be applied to prevent pilling.

[0028] During dyeing and finishing, pilling of these fabrics can be minimized by using relatively mild processing methods, such as pad dyeing of flat fabrics and resin finishing with crosslinking agents (usually done on dyed fabrics), to set the fibers and prevent them from being removed from the fabric during subsequent washing processes.

[0029] Removing surface hairs from modal and viscose fabrics will also reduce the tendency to pill. One way to do this is to singe the surface of the fabric by passing it through a flame.

[0030] In the case of modal and viscose, like many other fabrics, they pill during use and care. This is undesirable, and reducing the tendency of a fabric to pill can improve its attractiveness and practicality.

[0031] Modal and viscose fabrics may pill during dyeing and finishing, as well as during subsequent wear and care of garments made from them. Pilling can be controlled using the methods described above. Using higher twist yarns and weaving or knitting tighter fabrics will reduce pilling. Anti-pilling finishing agents can be applied to prevent pilling.

[0032] During dyeing and finishing, pilling of these fabrics can be minimized by using relatively mild processing methods, such as pad dyeing of flat fabrics and resin finishing with crosslinking agents (usually done on dyed fabrics), to set the fibers and prevent them from being removed from the fabric during subsequent washing processes.

[0033] Removing surface hairs from modal and viscose fabrics will also reduce the tendency to pill. One way to do this is to singe the surface of the fabric by passing it through a flame.

[0034] Another way to remove fuzz from the surface of cellulosic fabrics is through enzymatic treatment with cellulase. Cellulase treatment can successfully remove long fiber ends from the surface, but it is often ineffective on modal or viscose fabrics and is expensive in terms of both material costs and processing time.

[0035] Historically, various methods have existed in commercial fashion laundries for achieving a wash-down effect on indigo denim garments. These methods include the use of detergents, pumice, enzymes, and chemical bleaches, or combinations of two or more of these. These bleaches are used to accelerate the fading process of indigo. Bleaching is primarily intended to lighten the indigo color to achieve the desired final hue. Sodium hypochlorite, potassium permanganate, and, to a lesser extent, hydrogen peroxide and laccase are the main bleaching chemicals used to achieve the so-called "wash-down effect."

[0036] Sodium hypochlorite is used for bleaching in most cases due to cost and availability. However, chlorine-free bleaching technology has become a major focus in the denim finishing industry because AOX (aspirable halogenated organic compounds) is released into wastewater effluent.

[0037] Alternatives to bleaching agents, such as laccase, sulfinic acid derivatives, or glucose, offer better environmental acceptability, but present some practical application challenges. Therefore, major development efforts have focused on advanced oxidation processes (AOP), particularly ozonation.

[0038] Ozone has strong oxidizing power and has been found to have a strong potential for fading textile dyes. Currently available commercial machines (including garment processing machines and fabric preparation machines) use ozonation to fade indigo-dyed garments.

[0039] question Given the current state of the technology, there is a need for a process that allows for greater process flexibility and better control to achieve novel and unique effects in order to produce fabrics with the desired clean, soft-touch finish, whether in the form of Lyocell, Modal, or viscose garments or piece goods. Summary of the Invention

[0040] This invention provides a method for producing dyed and finished synthetic cellulose fiber fabrics or garments made from synthetic cellulose fiber fabrics with a clean, soft-touch finish.

[0041] This invention involves subjecting a synthetic cellulose fiber fabric to a wet processing method, inducing fibrillation on the fabric surface through mechanical action, followed by a tumbling treatment to achieve a clean, soft-touch finish. Prior to the tumbling treatment, the fabric is additionally treated with ozone, i.e., impregnated with an ozone solution or gaseous ozone under controlled conditions. Surprisingly, it has been found that the use of ozone in the process results in faster removal of surface fuzz from the fabric, leading to reduced processing time and chemical consumption. The mechanical treatment will induce fibrillation on the fabric surface in the case of lyocell fibers, or loosen the surface fibers of modal and viscose fibers. The tumbling treatment will achieve a clean, desirable soft-touch finish. The ozone treatment can be performed before, during, or after the wet processing.

[0042] According to a preferred embodiment of the invention, the fabric is in an undyed state prior to ozone treatment.

[0043] The main objective of this invention for a novel process for lignin-based cellulose in textiles is to solve or avoid inherent problems such as coarse fibrillation in lyocell or pilling in viscose and modal. A clean, soft-touch finish includes short lyocell fibrils on the fiber surface (these fibers are not long enough to tangle together), or short fibers on the surface of viscose / modal fabrics (these fibers are not long enough to tangle together to form a pill). These conditions are illustrated in the accompanying drawings.

[0044] It has also been found that ozone can be effective if it is generated on-site, for example by immersing the fabric in hydrogen peroxide and then exposing the immersed fabric to high-intensity UV light.

[0045] The method of the present invention can be applied to woven and knitted Lyocell, Modal, or viscose fabrics along their length. The method is also applicable to garments and fabrics made of Lyocell, Modal, or viscose, and is particularly useful for these fabrics.

[0046] The effect of ozone treatment appears to be one of weakening the surface fibers of lyocell fabrics, making the relatively long fibers formed during the intensive wet treatment phase easier to remove in the normal process of subsequent processing steps.

[0047] A secondary effect of ozone treatment on synthetic cellulose fiber fabrics or garments is that the degree of polymerization (DP) of cellulose appears to decrease. This loss of tensile strength seems significant enough to be used as a processing technique to more easily remove surface fibers from the fabric surface.

[0048] Preferably, ozone treatment is performed by introducing ozone-rich air into a closed mechanical treatment chamber containing the fabric, to which the fabric is then mechanically treated during ozone treatment. Afterwards, the ozone is removed from the chamber before the fabric is removed. Preferably, for the purposes of this invention, the mechanical treatment should be a tumbling process or a flattening process. Therefore, the mechanical treatment chamber can be a tumbling chamber or a chamber in which the fabric will undergo a flattening process.

[0049] In a preferred embodiment of the invention, ozone treatment uses an atmospheric concentration of 5 g ozone / Nm³. 3 Up to 200 g ozone / Nm 3 Gaseous ozone, or more preferably, a concentration of 20 g ozone / Nm³. 3 Up to 150 g ozone / Nm 3 The test was conducted at a temperature between 5ºC and 40ºC for a minimum duration of 5 minutes and a maximum duration of 75 minutes.

[0050] Preferably, the fabric is wet at the start of and during ozone treatment, with a moisture content in the range of 40% to 90% (w / w), more preferably in the range of 40% to 75% (w / w).

[0051] There are two different machine options that expose the product to gaseous ozone.

[0052] In the garment form, the machine takes the form of a large commercial washing machine. Garments are placed in a horizontal metal drum called a tumbler. Because ozone has a relatively short half-life, it is typically generated on-site by an ozone generator. In this case, ozone is generated via corona discharge, which offers the advantages of being more sustainable, having higher ozone yields, and being more cost-effective. The drum washing machine is equipped with an ozone generator that uses electricity to charge oxygen molecules into the incoming air, thus producing ozone. The corona discharge breaks down stable oxygen molecules, forming two oxygen free radicals. These oxygen free radicals can combine with oxygen molecules to form ozone. The generated ozone is injected into the sealed drum containing garments made of lyocell fabric. The duration of the garments' exposure to ozone depends on the weight of the garments in the drum. At the end of the processing cycle, any remaining ozone is expelled from the machine and decomposes into oxygen. This can happen in different ways, particularly by feeding the remaining gas in the drum into a heater where it decomposes at a temperature of approximately 300°C, or by feeding the gas into a catalytic ozone decomposition system, such as a "carulite®" filter. In this case, the ozone will be decomposed through a chemical reaction that occurs within the filter.

[0053] In the fabric application route, ozone generation is exactly the same as in the garment route. The fabric undergoes a flat-width treatment, passing through multiple rollers in enclosed compartments. This setup can be "standalone," with the fabric moving from one A-frame to another through sealed compartments, or it can be part of a flat-width fabric preparation production line.

[0054] The treatment conditions for gaseous ozone take into account fabric weight, processing time, and ozone concentration.

[0055] In another preferred embodiment of the invention, ozone treatment is performed by impregnating the fabric with an aqueous ozone solution and then subjecting the fabric to mechanical treatment.

[0056] In another preferred embodiment of the ozone treatment according to the invention, ozone is generated on-site. Any conventional technique for applying liquids to fabrics can be used to uniformly impregnate the fabric with a hydrogen peroxide solution. The fabric can be passed lengthwise through an aqueous pad bath, the moisture content of which is typically 65-80% of the fabric weight. Ozone is then generated by exposing the impregnated fabric to high-intensity UV light and performing gas extraction, after which the fabric undergoes mechanical treatment.

[0057] If the yarns of the synthetic cellulose fiber fabric have been sized or lubricated to facilitate weaving or knitting, it is preferable to subject the fabric to a desizing or scouring operation before applying ozone. This desizing or scouring can be a routine operation in which the fabric is passed through a scouring bath to remove the sizing or lubricant.

[0058] In a preferred embodiment of the invention, ozone treatment is performed as a pretreatment prior to further wet processing steps. It has been surprisingly found that ozone treatment of the fabric before conventional wet processing (such as jet dyeing) results in significantly less mechanical and chemical action required to achieve the desired clean, soft-touch finish. For example, cellulase is no longer needed. Ozone treatment is preferably performed as a pretreatment prior to the fibrillation induction step in lyocell. The latter step is the wet processing step, in which mechanical action applied to the wet fabric causes fibrillation on the fabric surface. This fibrillation is of the so-called primary fibrillation type, which produces relatively long, protruding fiber ends that, if left in situ, create an unsightly fuzzy effect on the fabric surface. The role of ozone treatment is to reduce the strength of these fiber ends, allowing them to be removed from the fabric surface during processing.

[0059] In subsequent wet processing steps, many fiber ends appear to be removed, while any remaining fiber ends are rubbed off the fabric surface during subsequent processing stages.

[0060] These subsequent wet processing steps for abrasion treatment can be dyeing steps, where the dyeing process applies the necessary mechanical action to the fabric. In a preferred embodiment of the invention, the wet processing includes a dyeing step. When the fabric is being processed along its length, this can be a jet dyeing operation using a commercially available water-driven jet dyeing machine or air-jet dyeing machine. In the case of garment processing, this can be a drum dyeing operation.

[0061] The method of this invention can use conventional dyes and dye formulations for cellulosic fibers, including dyes based on direct dyes, vat dyes, sulfur dyes, and reactive dyes. Furthermore, indigo-dyed yarn can be used as a base for fabrics in denim-type applications.

[0062] After the dyed fabric has been washed to remove any unfixed dye, it can be subjected to one or more conventional finishing treatments, including the application of a softening finish. These treatments can be performed after the dyeing and washing processes without requiring intermediate dyeing of the fabric.

[0063] At this stage, the surface of the dyed fabric has not yet achieved the desired clean and soft touch finish. The fabric may still appear flat and slightly uneven, and may have some fuzz attached. To achieve the desired finish, the fabric is tumbled (sometimes called beating), which creates a uniform pile on the fabric surface, initiating secondary fibrillation. This treatment is preferably carried out as a dry process, i.e., without the addition of liquid, but the fabric should remain moist, and its final drying can be performed at this step.

[0064] To impart a peach-touch finish to fabrics (especially garments and textiles), the fabric can be tumbled for an extended period in a rotary drum machine (such as a tumble dryer). Tumble dryers typically operate at temperatures between 70 and 100°C, usually between 70 and 85°C. Rope-like fabrics can be tumbled in a rope-like drum machine (such as the Biancalani Airo). The tumbling time for the rope fabric should be 30–60 minutes, preferably 40–50 minutes. The air temperature used should be 50–150°C. Shorter durations will result in incomplete fiber removal; longer durations are unnecessary to achieve the desired results and are economically impractical (a waste of time and money…).

[0065] Another preferred embodiment of the invention surprisingly found that performing these ozone treatment steps after the wet treatment step of the man-made cellulose fiber fabric also yielded effective results. The wet treatment step can be a dyeing process involving the mechanical action of the fabric; an example is jet dyeing, in which the fabric, in a rope-like form, is propelled through a dyeing machine by a liquid jet and thereby subjected to severe forces, such as bending and torsional forces, as well as impact and abrasion forces on the machine surface.

[0066] The dry lyocell fabric produced by the method of this invention is a dyed fabric with a clean and soft touch finish. The uniform, soft nap on the fabric surface gives it an attractive hand feel and a subtle sheen, sometimes referred to as a frosted effect. When the nap develops to a higher level, the fabric surface can be characterized by a peach-touch finish.

[0067] The dry modal or viscose fabric produced by the method of this invention is a dyed fabric with a clean and soft-touch finish, characterized by a low tendency to pill during subsequent wear and washing of garments made therefrom. The uniformly clean finish on the fabric surface gives the fabric an attractive appearance that is maintained throughout the entire lifespan of garments made therefrom.

[0068] Therefore, another aspect of the present invention is a fabric or garment finished using the process described above according to the present invention, which has a clean and soft touch finish. Both a peach-textured finish and a frosted effect can be considered specific embodiments of the clean and soft touch finish.

[0069] To illustrate the invention, two typical embodiments of the processing routes are described below. However, these embodiments do not limit the scope of the invention in any way. The invention also includes any other embodiments based on the same inventive concept.

[0070] Implementation Plan 1: Garment Manufacturing Process: This process is applied to the fabric in garment form before dyeing. Applying this process before dyeing / washing avoids any negative fibrillation issues.

[0071] 1. Wet the garment with a simple wetting detergent (1g / l), liquid to liquid ratio of 6:1, at 30°C for 5 minutes.

[0072] 2. Extract water until residual moisture content is ~60%.

[0073] 3. Treat with ozone for 20 to 60 minutes in a G2 ozone generator (the G2 ozone treatment machine was developed by Jeanologia SL of Paterna, Spain) at an ozone concentration of 100 g ozone / Nm³. 3 The machine has a volume of 3500 liters, a garment load capacity of 50 kg, and a rotation speed of 20 rpm.

[0074] 4. Rinse in 40°C water (5 minutes, liquid to cargo ratio 6:1).

[0075] 5. Applications of traditional clothing dyeing.

[0076] 6. Soften to achieve the desired aesthetic effect (e.g., typical polyethylene softener or micro-silicone or blend).

[0077] 7. Dry in a rotating drum at 70ºC for 45 minutes.

[0078] Implementation Plan 2: Fabric Process Route: Ozone can be used in combination with a variety of fabric preparation systems shown in Table 1 below (referred to as System AD in this document).

[0079] Table 1: system# Singeing Desizing bleach causticization Mercerizing Sanfor (pre-shrinking) A X X X B X X X X C X X X X D X X X X

[0080] Singeing and desizing have been described in the specification of this invention.

[0081] Bleaching is usually carried out at 20-25°C as a cold pad batch treatment. The concentration of the bleaching solution is as follows: 60 g / L hydrogen peroxide (35%), 40 g / L sodium hydroxide (100%), 4 g / L wetting detergent, and 4 g / L peroxide stabilizer.

[0082] Causticization refers to the treatment of flat-width fabrics in 6° Baumé NaOH, in the following sequence: padding, dwelling, and flat-width washing.

[0083] Mercerizing refers to treating fabrics in 30° Baumé NaOH in the following sequence: padding, resting, and washing on the same surface.

[0084] In this embodiment, ozone treatment can be performed on a G2 dynamic ozone generator after all fabrics listed in Table 1 have been treated: the operating speed is 10-30 m / min, and the ozone power is 30 g ozone / Nm³. 3 .

[0085] Fabrics treated in this way can now be dyed as fabric and made into garments for washing, or made into garments in their undyed form and then dyed as garments.

[0086] Fabrics and garments processed according to the present invention exhibit the same visual appearance as fabrics and garments treated through conventional commercial routes to achieve a clean, soft-touch finish. However, the method according to the present invention has a less environmental impact than well-known conventional commercial routes such as alkali treatment, mercerizing, and enzyme treatment. Attached image description: Figure 1 The image shows a Lyocell fabric before ozone modification—note the surface fuzz.

[0088] Figure 2 The image shows the state of un-ozone-modified Lyocell fabric after washing—note the high degree of fibrillation and subsequent entanglement of fibrils and fibers.

[0089] Figure 3 The image shows a fabric after washing, pretreated in ozone according to the present invention. Note that there are no pilling fibers on the fabric surface, and only short fibrils are present.

[0090] The photographs (Figures 4 and 5) illustrate the effect achieved by viscose. Since viscose does not have a tendency to become fibrous, the ozone treatment (applied according to the invention) prevents fuzz from tangling and forming pills on the fabric surface. Figures 4 and 5 show viscose fiber fabrics after multiple washes: Figure 4 shows an untreated viscose fabric—note the messy, pilling appearance of the fabric surface. Figure 4a The front view of the fabric is shown, and Figure 4b The fabric edge view is displayed.

[0091] Figure 5 shows the same fabric, washed in the same way, but pre-treated in ozone. Notice the cleaner surface appearance. Figure 5a The front view of the fabric is shown, and Figure 5b The fabric edge view is displayed.

Claims

1. A method for producing a dyed and finished man-made cellulose fiber fabric with a clean, soft-touch finish, comprising subjecting the fabric to a wet processing treatment using mechanical action, treating the fabric with ozone, and additionally tumbling the fabric after ozone treatment.

2. The method according to claim 1, wherein the fabric is in an undyed state prior to ozone treatment.

3. The method of claim 1, wherein the ozone treatment is carried out by introducing ozone-rich air into a closed mechanical treatment chamber containing the fabric, and then mechanically treating the fabric therein during the ozone treatment time.

4. The method according to claim 3, wherein the ozone treatment uses an atmospheric ozone concentration of 5 g ozone / Nm³. 3 Up to 200 g ozone / Nm 3 Gaseous ozone, or more preferably, a concentration of 20 g ozone / Nm³. 3 Up to 150 g ozone / Nm 3 The temperature is between 5°C and 40°C, and the shortest duration is 5 minutes and the longest duration is 75 minutes.

5. The method according to claim 3, wherein the fabric is wet at the start and during ozone treatment, and its moisture content is in the range of 40% to 90% (w / w), preferably in the range of 40% to 75% (w / w).

6. The method of claim 1, wherein the ozone treatment is performed by impregnating the fabric with an aqueous ozone solution and then subjecting it to mechanical treatment.

7. The method of claim 1, wherein the ozone treatment is performed by impregnating the fabric with a hydrogen peroxide solution and exposing the impregnated fabric to high-intensity UV light, followed by mechanical treatment.

8. The method according to claim 1, wherein the wet processing includes a dyeing step.

9. The method of claim 1, wherein the ozone treatment is performed as a pretreatment prior to a further wet processing step.

10. The method of claim 1, wherein the fabric is in the form of a garment or cloth.

11. The method according to claim 1, wherein the tumbling process is a tumbling process performed in a rotary drum machine for 30-60 minutes, preferably 40-50 minutes, to impart a peach-touch finish.

12. A fabric or garment finished using the method according to claim 1, and having a clean and soft-touch finish.

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