Field of Invention

The present disclosure generally relates to a process for recycling of reclaimed cellulosic material that comprises post industrial or post consumer waste cotton rich material or cellulosic fiber or fabric waste. Particularly, the disclosure relates to a process for preparing moulded bodies such as staple fiber, filament, film, sponge of viscose, or modal or lyocell type from pre and post industrial or consumer waste cotton rich material or cellulosic fiber or fabric waste.

Background

In today's fast-fashion world, each person on an average is buying and discarding a larger number of clothes than ever before. During the manufacture of apparels, a large amount of waste is generated in the form of scrap cuttings. Waste is also generated once these clothes are discarded by the users. Currently, only a fraction of cotton or cellulosic fiber based textile is recycled. The remaining is either incinerated or ends up in landfills, thereby causing pollution.

Cotton textiles account for about one-third of the global textile production. Currently, cotton textiles are generally recycled by converting fabric into fibre form by shredding and opening. The fibres obtained by shredding are blended with other fibres or processed alone to make yams. The process often weakens the fibres and the resultant yarn is coarser and has lower mechanical properties, thus resulting in products that are of lower quality and with more faults in yam and fabric therefrom. Some alternate technologies are disclosed for example in US9751955 B2, US2018/0215893 and US20160369456A1 for recycling waste. Such technologies however require complex pre-treatment and conversion to pulp.

There remains a need for a process by which cotton rich material such as waste cloth scraps and used clothes are recycled in an easy and efficient manner.

Summary

The disclosure provides a process of preparing moulded cellulosic material from reclaimed cellulosic material. The process comprises the steps of treating the reclaimed cellulosic material with at least one bleaching compound, to reduce the degree of polymerization of the reclaimed cellulosic material to a cupriethylenediamine viscosity less than 500ml/g, to obtain bleached reclaimed cellulosic material, washing the bleached reclaimed cellulosic material with water, shredding the bleached and washed reclaimed cellulosic material, to obtain treated reclaimed cellulosic material, preparing a dope by a viscose or lyocell process comprising the treated reclaimed cellulosic material, and preparing a moulded cellulosic material from the dope so prepared.

Brief Description of Figures

Figure 1, illustrates the reclaimed cellulosic material, in accordance with an embodiment of the disclosure.

Figure 2, illustrates the bleached reclaimed cellulosic material, in accordance with an embodiment of the disclosure.

Figure 3, illustrates the treated reclaimed cellulosic material, in accordance with an embodiment of the disclosure.

Figure 4, discloses a process in accordance with an embodiment.

Figure 5, discloses a process in accordance with an embodiment.

Figure 6, discloses a process in accordance with an embodiment.

Detailed Description

For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the disclosed composition and method, and such further applications of the principles of the disclosure therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates. It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.

Reference throughout this specification to“one embodiment”“an embodiment” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrase“in one embodiment”,“in an embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

In its broadest scope, the present application relates to a process for preparing cellulosic moulded bodies such as staple fiber, filament, film, and sponge of viscose or modal or lyocell type from reclaimed cellulosic material.

Reclaimed cellulosic material herein refers to waste cotton rich fabric including pre-consumer and post-consumer waste cotton rich fabric or cellulosic fiber or fabric waste. The pre-consumer waste fabric includes the cotton-rich fabric that is generated as scrap cutting during the manufacture of apparel, furnishing, etc. The post-consumer waste fabric includes cotton rich fabric discarded by consumers. The cotton rich fabrics that are discarded by consumers include both fabrics that are used by the consumers or in some cases, fabrics that are in fact unused before being discarded by the consumers. Figure 1, illustrates the reclaimed cellulosic material. In accordance with an aspect, the reclaimed cellulosic material comprises cotton rich fabric that includes at least 80% cotton or cellulosic material. Preferably, the reclaimed cellulosic material comprises at least 90% cotton or cellulosic material. Reclaimed cellulosic material herein also refers to other cotton waste materials such as cotton linters, combernoil, flats/carding waste.

The process of preparing cellulosic moulded bodies from reclaimed cellulosic material comprises treating the reclaimed cellulosic material to obtain treated reclaimed cellulosic material; preparing a dope from the treated reclaimed cellulosic material and preparing a moulded cellulosic material from the dope so prepared. The moulded cellulosic material that may be prepared by said process includes staple fiber, filament, film, and sponge of viscose or modal or lyocell type. In the first step of the process, the reclaimed cellulosic material is treated. The treatment makes the reclaimed cellulosic material suitable for making a dope for a viscose or lyocell or modal or other man made cellulosic fiber manufacturing process.

The treatment of reclaimed cellulosic material comprises treating the reclaimed cellulosic material with one or more bleaching compounds to reduce the degree of polymerization of the reclaimed cellulosic material and to remove any dye or colour from the reclaimed cellulosic material to obtain bleached reclaimed cellulosic material. The bleached reclaimed cellulosic material is then washed with water and shredded into smaller pieces.

In accordance with an aspect, the reclaimed cellulosic material is treated with a bleaching compound that not only removes colour but also reduces the degree of polymerization (DP). Preferably, the degree of polymerization of the reclaimed cellulosic material after the treatment with the bleaching compound as measured by cupriethylenediamine (CED) viscosity is reduced to less than 500ml/g. In accordance with an embodiment the degree of polymerization of the reclaimed cellulosic material after the treatment with the bleaching compound as measured by cupriethylenediamine (CED) viscosity is between 180 ml/g to 270ml/g for the viscose process, and between 350ml/g to 500 ml/g for the lyocell process.

The bleaching compound is selected from a group comprising sodium hypochlorite, sodium hydrosulphite, chlorine dioxide, hydrogen peroxide or a mixture thereof. In accordance with an embodiment, the bleaching compound is hypochlorite preferably sodium hypochlorite.

The reclaimed cellulosic material is treated for a time period of upto 4 hours and at a temperature of upto 80 degree Celsius such that the specified viscosity is obtained. In accordance with an aspect, the weight : weight ratio of reclaimed cellulosic material to the solution of bleaching compound is in a range of 1:2 to 1: 15 and the concentration of bleaching compound is in the range of 3 to 30 grams per litre (gpl). The treatment with the bleaching compound is done over a broad range of pH. In accordance with an embodiment, the treatment with the bleaching compound is done between pH 5 to 12. Figure 2, illustrates the bleached reclaimed cellulosic material. Alternatively, the reclaimed cellulosic material can be subjected to bleaching with other combinations of a suitable time and temperature as known in the art. For example, the reclaimed material can be treated with the bleaching compound, and the so-treated reclaimed material is left open for bleaching under ambient conditions over many hours.

The bleached reclaimed cellulosic material is then washed with water to remove the bleaching agent and the reaction products from the bleached reclaimed cellulosic material. In accordance with an aspect, the bleached reclaimed cellulosic material is washed with water having a temperature in the range of 30 to 90 degree Celsius and a pH of between 4 to 8.

In the next step of the process, the bleached and washed reclaimed cellulosic material is shredded to obtain treated reclaimed cellulosic material. In accordance with an aspect, the bleached and washed reclaimed cellulosic material is shredded to a size less than 25 mm x 25mm to obtain treated reclaimed cellulosic material. Preferably, the bleached and washed reclaimed cellulosic material is shredded to a size less than 5 mm x 5 mm to obtained treated reclaimed cellulosic material. Figure 3, illustrates the treated reclaimed cellulosic material. The treated reclaimed cellulosic material may retain fabric form or be reduced to yam or fiber.

In accordance with an embodiment, the excess water from the bleached and washed reclaimed cellulosic material is optionally removed to reduce the moisture content and optionally to obtain dried reclaimed cellulosic material, prior to shredding. The moisture content of the washed reclaimed cellulosic material is reduced to between 30 % to 70% of wet material. Water from the washed reclaimed cellulosic material may be removed by any known method including but not limited to pressing, centrifugation and drying. Any other known method for reducing the moisture content may also be used to obtained dried reclaimed cellulosic materials. The dried reclaimed cellulosic material is then shredded into small pieces to obtain treated reclaimed cellulosic material.

The preceding steps thus convert the reclaimed cellulosic material into shredded reclaimed cellulosic material i.e., the treated reclaimed cellulosic material that is white in colour has a degree of polymerization of less than 500 ml/g and a size less than 25 mm x 25mm. The process of preparing moulded cellulosic material further comprises preparing a dope for a viscose or lyocell process and preparing a moulded cellulosic material from the dope so prepared.

The treated reclaimed cellulosic material obtained is converted into moulded cellulosic material, by using conventional viscose or lyocell fiber manufacturing process. The moulded cellulosic material that may be prepared by said process includes staple fiber, filament, film, and sponge of viscose or modal or lyocell type.

In accordance with an embodiment, the treated reclaimed cellulosic material may be used as an only source of cellulose for the viscose or lyocell manufacturing process.

In accordance with an alternate embodiment, the treated reclaimed cellulosic material may be mixed with dissolving grade pulp during the viscose or lyocell or fiber manufacturing process. The shredded reclaimed cellulosic material is mixed with the dissolving grade pulp in a range of 5% to 90%. The shredded reclaimed cellulosic material may be mixed with the dissolving grade pulp in an amount preferably between 5 to 40%.

In accordance with an embodiment, treated reclaimed cellulosic material may be added at various stages during the viscose process, which comprises the following steps in a continuous, batch or semi-continuous manner or a combination thereof: a steeping step, wherein the dissolving grade pulp is immersed in 15% to 20% aqueous sodium hydroxide (NaOH) to swell the cellulose fibres and to convert cellulose to alkali cellulose; a pressing step, wherein swollen alkali cellulose mass is pressed to a wet weight equivalent of 2.5 to 3.5 times the original pulp weight; a shredding step, wherein the swollen alkali is shredded mechanically, to increase the surface area of the alkali cellulose; a pre-ageing step, wherein the alkali cellulose is aged under controlled conditions of time and temperature to depolymerize the cellulose to a desired degree of polymerization; a xanthation step, wherein the aged alkali cellulose is allowed to react with carbon disulphide under controlled temperature to form cellulose xanthate; a viscose dope preparation step, wherein the cellulose xanthate is dissolved in dilute sodium hydroxide at dissolution temperature of 10 to 25 °C to obtain a viscous orange coloured solution called "viscose"; a ripening step, wherein the viscose is allowed to stand for a period of time to "ripen"; a filtering step, wherein the viscose is filtered to remove undissolved materials that might disrupt the spinning process or cause defects in the rayon filament; a degassing step, wherein bubbles of air entrapped in the viscose is removed; a spinning step, wherein the viscose solution is metered through a spinnerette into a spin bath containing sulphuric acid, sodium sulphate, and zinc sulphate to obtain filaments; a drawing step wherein the filaments are stretched while the cellulose chains are still relatively mobile; a washing step wherein the freshly regenerated fibres are washed to remove salts and other water-soluble impurities and; a cutting: step wherein the fibres are cut to provide a fibre which can be processed in much the same way as cotton.

In accordance with an embodiment, the treated reclaimed cellulosic material is added at the steeping step of the viscose manufacturing process along with dissolving grade pulp. Figure 4, discloses a process wherein, the treated reclaimed cellulosic material is added along with dissolving grade pulp to the pulper at the beginning of the viscose manufacturing process.

In accordance with an alternative embodiment, the treated reclaimed cellulosic material is subjected to a steeping process before it is introduced into the viscose manufacturing process. In this embodiment, the treated reclaimed cellulosic material is steeped in a 15% to 20% aqueous sodium hydroxide (NaOH); followed by pressing to remove excess alkali and then added at the pre-ageing step of the viscose manufacturing process.

In yet another embodiment, preparing the dope from the treated reclaimed cellulosic material comprises the steps of steeping the treated in 15% to 20% aqueous sodium hydroxide, pressing the steeped treated reclaimed cellulosic material to remove excess aqueous sodium hydroxide and then added at the xanthation step of viscose making process along with pre-aged alkcell. In accordance with an aspect, preparing the dope in such a manner allows the use of treated reclaimed cellulosic material that has lower initial cupriethylenediamine (CED) viscosity and yet allows in maintaining high recycle content. Figure 5, illustrates such a process where the treated reclaimed cellulosic material is subjected to a steeping process before it is introduced into the viscose manufacturing process.

The dope so prepared may then be extruded, regenerated, bleached, washed and dried to obtain viscose staple fibre with the properties that are comparable to the Viscose Staple Fibre (VSF) obtained through virgin pulp.

While the fiber part of reclaimed material should contain > 95% cellulosic, the rest may be insoluble synthetics fibers. In accordance with an embodiment, the undissolved synthetic fibres or other contaminants may be removed from the dope by filtration. The filtration may be optimized amongst many known methods with woven or non-woven screens or particle beds etc. The cleaning of filters may be carried out by manual or automated changing of screens, or back-washing, optionally with occasional scrapping or vacuum-assisted removal of fibrous residue to remove the synthetic fibers efficiently. One of the ways of efficiently removing the synthetic or contaminants is through selection from filtration methodologies as defined by filtration rating, back-wash filtration system, its duration and frequency etc.

In accordance with an embodiment, the viscose quality parameters such as filterability index (KW), ripening index (RI) of the present invention are comparable to the regular viscose process with virgin pulp. The treated reclaimed cellulosic material of the present invention has certain characteristics, described elsewhere in this application, and is amenable to the lyocell process. A further aspect of the present disclosure is a method of producing lyocell comprising using the treated reclaimed cellulosic material of the present invention as a starting material in the lyocell process. The treated reclaimed cellulosic material is added during the pulper stage of the lyocell process along with dissolving grade pulp for producing lyocell fibers as per the process known in the art.

In accordance with an embodiment, for the lyocell process, preparing the dope from the treated reclaimed cellulosic material comprises adding the treated reclaimed cellulosic material to aqueous NMMO in the slurry preparation step of the lyocell manufacturing process, along with dissolving grade pulp. Figure 6, illustrates such a process where the treated reclaimed cellulosic material is introduced into the pulper i.e., the slurry preparation stage of the lyocell manufacturing process.

It will be apparent to those skilled in the art that various modifications and variations can be made to the method/process of the present disclosure without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the method/process disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalent.

Examples:

Example 1: Conventional viscose (control)

(i) Dope preparation

Dissolving grade pulp was first steeped in 18% caustic soda solution. This was followed by pressing and shredding to obtain Alkali cellulose (alkcell). The alkcell was further depolymerized, and subsequently xanthated by the addition of carbon disulfide (33% based upon the weight of cellulose). The cellulose xanthate was then dissolved in a caustic soda solution by mixing operation to obtain a viscose dope solution containing 9 % cellulose and 5.5 % caustic soda. The viscose was then ripened for 10-12 hours to obtain spinning viscose characterized by a ball fall viscosity in the range 60 to 90 seconds, and a Gamma number in the range of 45 to 48.

(ii) Spinning and after-treatment

The viscose was spun to form filament tow by extrusion of the viscose through orifices into a spinning bath containing 110 to 120 grams per liter (gpl) sulfuric acid, 10 gpl zinc sulphate and 330 to 350 gpl sodium sulphate. The filaments were withdrawn from the bath, passed over a first godet to a spinning roll to achieve a stretch of ~ 60 %. The spinning speed was 60 meters per minute. The fibres were further washed, desulfurized, finished with a lubricant, and dried by usual methods. The fibres obtained had an average linear density of 1.0 to 1.5 denier depending on flow and spinning roll settings.

Example 2: Present invention: Reclaimed cellulosic material (cotton recycle content: 5%

(i) Treatment of cotton waste (reclaimed cellulosic material)

Treatment sequence: Bleaching - washing with water - water extraction - shredding. Post-industrial coloured cotton waste (reclaimed cellulosic material) was decolourized using hypochlorite solution (bleaching compound) containing 1% equivalent active chlorine (cotton waste: hypochlorite solution ratio of 1:6 wt/wt), at 55°C. The bleached cotton waste was then washed with hot water. Excess water was extracted to achieve a moisture content of 40 to 50 % in the treated material. The cotton waste thus treated was then shredded into smaller pieces preferably less than 5 mm x 5 mm using a mechanical shredder to obtain treated cotton waste that is, the treated reclaimed cellulosic material. (ii) Dope preparation

The raw material comprising 5% of treated reclaimed cellulosic material, and 95% dissolving grade pulp was steeped in 18% caustic soda solution. This was followed by pressing and shredding to obtain Alkali cellulose (alkcell). 5 % of treated reclaimed cellulosic material was added along with DG pulp. The alkcell was further depolymerized, and subsequently xanthated by the addition of carbon disulfide (32-34% based upon the weight of cellulose). The cellulose xanthate was then dissolved in a caustic soda solution by mixing operation to obtain a viscose dope solution containing 8.5 to 9.5 % cellulose and 5.0 to 6.0 % caustic soda (NaOH/Cellulose ratio ~ 0.56). The viscose was then ripened for 10 to 12 hours to obtain. Spinning viscose characterized by a ball fall viscosity of 60 to 90 seconds and Gamma number in the range 45 to 48.

(iii) Spinning and after treatment

The spinning viscose was spun to form filament tow by extrusion through orifices into a spinning bath containing 110 to 120 grams per liter (gpl) sulfuric acid, 10 gpl zinc sulphate and 330 to 350 gpl sodium sulphate. The filaments were withdrawn from the bath, passed over a first godet to a spinning role to achieve a stretch of ~ 60 %. The spinning speed was 60 meters per minute. The fibres were further washed, desulfurized and finished with a lubricant, and dried by usual methods. The fibres obtained had an average linear density of 1.0 to 1.5 denier depending on flow and spinning roll settings.

Example 3: Present invention: Reclaimed cellulosic material (Cotton recycle content): 20 %

(i) Treatment sequence:

Bleaching - washing with water - water extraction - shredding. The process was carried out in a matter similar to that in example 2. (ii) Dope preparation

The raw material comprising 20% of treated reclaimed cellulosic material (pretreated cotton waste) and 80% dissolving grade pulp was steeped in 15 to 20 % caustic soda solution. This step was followed by pressing and shredding to obtain Alkali cellulose (alkcell). The alkcell was further depolymerized, and subsequently xanthated by the addition of carbon disulfide (32-34% based upon the weight of cellulose). The cellulose xanthate was then dissolved in a caustic soda solution by mixing operation to obtain a viscose dope solution containing 8.5 to 9.5 % cellulose and 5.0 to 6.0 % caustic soda (NaOH/Cellulose ratio ~ 0.56). The viscose was then ripened for 10 to 12 hours to obtain spinning viscose possessing ball fall viscosity of 60 to 90 seconds and Gamma number in the range 45 to 48.

(iii) Spinning and after treatment

The viscose was spun to form filament tow by extrusion of the viscose through orifices into a spinning bath containing 110 to 120 gpl sulfuric acid, 10 gpl zinc sulphate and 330 to 350 gpl sodium sulphate. The filaments were withdrawn from the bath, passed over a first godet to a spinning role to achieve a stretch of ~ 60 %. The spinning speed was 60 meters per minute. The fibres were further washed, desulfurized and finished with a lubricant, and dried by usual methods. The fibres obtained had an average linear density of 1.0 to 1.5 denier depending on the flow and spinning role settings.

Example 4: Present invention: Reclaimed cellulosic material (Cotton recycle content): 40 %

(i) Treatment sequence:

Bleaching - washing with water - water extraction - shredding. The process was carried out in a matter similar to that in example 2. (ii) Dope preparation

The raw material comprising of 40% of treated reclaimed cellulosic material (pretreated cotton waste) and 60% dissolving grade pulp was steeped in 18 % caustic soda solution followed by pressing and shredding to form Alkali cellulose (alkcell). The alkcell was further depolymerized, and subsequently xanthated by the addition of carbon disulfide (32-34% based upon the weight of cellulose). The cellulose xanthate was then dissolved in a caustic soda solution by mixing operation to obtain a viscose dope solution containing 9.4 % cellulose and 4.9 % caustic soda (NaOH/Cellulose ratio ~ 0.56). The viscose was then ripened for 10 to 12 hours to obtain spinning viscose having ball fall viscosity of 64 seconds and Gamma number in the range 45 to 48.

(iii) Spinning and after treatment

The viscose was spun to form filament tow by extrusion of the viscose through orifices into a spinning bath containing 110 gpl sulfuric acid, 10 gpl zinc sulphate and 335 gpl sodium sulphate. The filaments were withdrawn from the bath, passed over a first godet to a spinning role to achieve a stretch of ~ 60 %. The spinning speed was 60 meters per minute. The fibres were further washed, desulfurized and finished with a lubricant, and dried by usual methods. The fibres obtained had an average linear density of 1.20 denier depending on flow and spinning role settings.

Procedure for Examples: 5 -8 Present invention: Reclaimed cellulosic material (Cotton recycle content): (10 %, 40%, 60% and 80%)

(i) Treatment sequence:

Bleaching - washing with water - water extraction - shredding. The process was carried out in a matter similar to that in example 2 except that, the treated cotton waste material obtained was charged into a rotary dryer and was further dried for a period up to 2 hours while passing hot air through the dryer. Exhaust temperature of the air was monitored and drying was stopped after reaching exhaust temperature of 80°C.

(ii) Dope preparation:

Dissolving grade pulp and treated reclaimed cellulosic material ( requisite % ) are together suspended in aqueous solution of NMMO (N-methyl morpholine oxide) in a high speed mixing device to form cellulose suspension (slurry) containing 12% of solid cellulose content. This slurry is then introduced into a high viscosity mixing equipment which is operated under vacuum to effect evaporation of water from the slurry at a temperature 95-100°C and vacuum of 710 mm Hg to obtain dope solution with a zero shear viscosity of 1210 Pa.s at

105°C.

(iii) Spinning and after treatment

The dope solution formed as above is extruded through suitable nozzles at a range of temperatures 100°C + 10 depending on the viscosity of the solution. The cellulose fibre is regenerated after passing through an air gap into the spinning bath, having the concentration of NMMO of 20 to 22% in water. The fibres are drawn off, cut into staple fibres, washed, bleached, finished, dried. The fibres obtained had an average linear density of 1.15 denier depending on flow and spinning speed. The target average linear density is 1.2 ±0.3 denier depending on flow and spinning speed.

Characterization methods

• CED viscosity measurement is done using standard method - ISO 5351 :2010 (E).

• Titration based methods for cellulose and alkali measurement. Table 1: Comparison of dope properties

Table 2: Comparison of spinning parameters

Table 1 and 2, illustrate that the dope prepared from the traditional method and that prepared using various concentrations of reclaimed cellulosic material (cotton recycle) standard dope preparation and spinning parameters. Thus, the process as disclosed does not require any special process equipment.

Table 3: Comparison of Viscose fibre properties

5

As disclosed above in Tables 3, fibers prepared using the traditional viscose process and those prepared using the inventive method result in obtaining fibers with comparative properties.

Table 4: Comparison of Lyocell fibre properties

0

As disclosed above in Tables 4, fibers prepared using the traditional lyocell process r and those prepared using the inventive method result in obtaining fibers with comparative properties. Specific embodiments are disclosed hereinafter:

A process of preparing moulded cellulosic material from reclaimed cellulosic material comprising the steps of treating the reclaimed cellulosic material with at least one bleaching compound, to reduce the degree of polymerization of the reclaimed cellulosic material to a cupriethylenediamine viscosity less than 500ml/g, to obtain bleached reclaimed cellulosic material; washing the bleached reclaimed cellulosic material with water; shredding the bleached and washed reclaimed cellulosic material, to obtain treated reclaimed cellulosic material; preparing a dope for a viscose or lyocell process comprising the treated reclaimed cellulosic material; and preparing a moulded cellulosic material from the dope so prepared.

Such process(es), wherein the reclaimed cellulosic material is selected from pre consumer or post-consumer waste cotton rich fabric

Such process(es), wherein the reclaimed cellulosic material is selected from pre consumer or post-consumer waste selected from cellulosic fiber or fabric waste.

Such process(es), wherein the reclaimed cellulosic material is cotton rich fabric that includes at least 80% cotton or cellulosic material, preferably at least 90% cotton or cellulosic material.

Such process(es), wherein the bleaching compound is selected from a group comprising sodium hypochlorite, sodium hydrosulphite, chlorine dioxide, hydrogen peroxide or a mixture thereof.

Such process(es), wherein the reclaimed cellulosic material is treated with the bleaching compound for a time period of up to 4 hours, at a temperature of up to 80 degree Celsius.

Such process(es), wherein the weight: weight ratio of reclaimed cellulosic material to the bleaching compound is in a range of 1:2 to 1:15.

Such process(es), wherein the concentration of the bleaching compound is in the range of 3 to 30 grams per litre. Such process(es), wherein the treatment with bleaching compound is performed at a pH in the range of 5 to 12.

Such process(es), wherein the bleached reclaimed cellulosic material is washed with water having a temperature in the range of 30 to 90 degree Celsius and a pH in the range of 4 to 8.

Such process(es), wherein the degree of polymerization of the bleached reclaimed cellulosic material is reduced to a cupriethylenediamine viscosity between 180 ml/g to 270ml/g for the viscose process

Such process(es), wherein the degree of polymerization of the bleached reclaimed cellulosic material is reduced to a cupriethylenediamine viscosity between 350 ml/g to 500 ml/g for the lyocell process

Such process(es), wherein the moisture content of the bleached and washed reclaimed cellulosic material is reduced to between 5% to 70% of wet material, before shredding.

Such process(es), wherein the size of the bleached and washed reclaimed cellulosic material is reduced to less than 25mm x 25mm by shredding.

Such process(es), wherein preparing the dope from the treated reclaimed cellulosic material comprises adding the treated reclaimed cellulosic material to a steeping step of a viscose manufacturing process, along with dissolving grade pulp.

Such process(es), wherein preparing the dope from the treated reclaimed cellulosic material comprises steps of steeping the treated reclaimed cellulosic material in a 15% to 20% aqueous sodium hydroxide, pressing the steeped treated reclaimed cellulosic material to remove excess aqueous sodium hydroxide; and adding the reclaimed cellulosic material so obtained at a pre-aging step of the viscose manufacturing process.

Such process(es), wherein the treated reclaimed cellulosic material is steeped in 15 to 20% caustic aqueous sodium hydroxide solution, pressing to the steeped treated reclaimed cellulosic material to remove excess aqueous sodium hydroxide and added at a xanthation step of viscose making process along with pre-aged alkcell. Such process(es), wherein preparing the dope from the treated reclaimed cellulosic material comprises adding the treated reclaimed cellulosic material to aqueous NMMO in the slurry preparation step of lyocell manufacturing process, along with dissolving grade pulp.

Such process(es), wherein the ratio of treated reclaimed cellulosic material to dissolving grade pulp is in a range of 5 to 90%

Such process(es), wherein the treated reclaimed cellulosic material is the only source of cellulose for the viscose or lyocell process.

Such process(es), wherein the moulded cellulosic material is a staple fiber, filament, film, sponge of viscose or modal or lyocell type.

Industrial Applicability

The process as disclosed allows for the recycling of waste cotton rich material such as scraps and used clothes in an easy and efficient matter. The process allows for the simpler conversion of post-industrial cotton waste into ready-to-use raw material for the viscose or lyocell process. The process converts multiple coloured cotton waste into white shredded material in a fewer number of steps as compared to the prior art documents. The process is such that the single step of bleaching results both in the reduction of the degree of polymerization as well as the discolouration of the waste cotton rich material. The white shredded material can be added alone or with DG pulp while preparing the moulded articles using standard processes. Moreover, unlike the processes disclosed in the prior art documents such as, the process is simple as it allows conversion of recycled cotton into viscose or lyocell fibres without passing through stages of pulp making which is cumbersome, high in effluent and energy intensive. Thus, the process is economical and results in the lesser generation of effluents and therefore is environmentally friendly.

Further as illustrated in Table 1 and 2, above, the dope prepared from the traditional method and that prepared using various concentrations of reclaimed cellulosic material (cotton recycle) has standard dope preparation and spinning parameters. Thus, the process as disclosed does not require any special process equipment. The process is crafted such that all the mechanical and cross-sectional properties of the fibre remain intact. Thus, it allows for the production of viscose or lyocell fibres that are comparable to the fibres that are obtained using virgin wood pulp. As disclosed above in Tables 3 and 4, fibers prepared using the traditional viscose and lyocell process respectively and those prepared using the inventive method result in obtaining fibers with comparative properties.