[0001] The disclosure pertains to producing a worn appearance to textiles. In particular, the present invention discloses a washing process for producing a wash out effect, in particular a stone washing effect, at a textile using a washing machine loaded with the textile and a mechanical abrasive.

[0002] It is known to wash textiles, particularly denim textiles, such as indigo dyed denim textiles, with various types of stones for producing a worn effect. These stones may be of natural or synthetic origin, comprising for instance rock and particularly pumice. The stones may be also synthetically formed by compacting smaller stones, including powders, crystals, and granules, and/or artificial stones formed by a molten material. The stones usually have an essential spherical shape in the size of up a tennis ball. Other abrading materials than stones, such as, wood, sand, rubber pieces, glass pieces, and polymeric foams have been used as well. The underlying abrading processes are usually referred to as stone washing.

[0003] Although stone washing is usually practiced with indigo-dyed denim garments, stone washing in general is applicable to any textile/fabric articles which are made at least in part of yarns or fibers which are pigmented or dyed in such a way as to exhibit visible variations in color and/or texture as a result of mechanical and/or chemical abrasion. Stone washing may be also applied to a variety of natural or synthetic fabrics. For instance, silk, satin, crepe and rayon may be treated by stone washing.

[0004] Any conventional washing machine is loaded with these materials and the textile to be treated and subjected to agitating and/or spinning for abrading the textile's surface. This is usually performed in the line with different washing programs of a washing process employing at the same time chemical abrasives, such as sodium permanganate, and other washing compounds, such as antibackstainers and detergents.

[0005] During agitating and/or spinning most of these abrading materials crum ble/decompose and/or are getting soaked with additives used for producing the wash out effect, such as a stone washed effect.

[0006] Crumbling produces debris out of small material pieces, such as a sand or sludge. The small material pieces collect in the equipment of a washing machine and downstream thereof, such as filters and drainage areas, as well as in the stone washed fabric, e.g. pockets and folds. In addition, these small material pieces are often soaked with detrimental additives, causing for instance environmental waste problems and/or health problems to the person wearing the textile. The collection and removal of this debris is associated with high water consumption and usually requires further treatment of the debris containing waste water, for instance filtering and/or treatment in a sewage plant. Another drawback is the propagation of dust generated from handling e.g. stones in storage and shipment prior to washing.

[0007] In addition, larger material pieces may cause damage to various compo nents of the washing machine, such as overload damage to the motor, and mechanical damage to transport mechanisms and the washing drum, and should be therefore re moved from the washing drum. Furthermore, high labor affords associated with the manual removal of material pieces from e.g. pockets or folds of the fabric may arise.

[0008] Another drawback resides in that these materials produce an irregular abrasion effect on the textile, i.e. some portions of the treated textile is rather intact whereas other portions of the textile are subjected to high wear. The wear may even result in destruction of the fibers forming the textile, such that the textile needs to be discarded.

[0009] Further attempts included the preparation of synthetic materials which partially overcome these disadvantages but require a complex production process for the abrasive. For instance, US 5,215,543 A and US 4,1 14,426 A disclose a washing process comprising synthetic stones made of compacted powder comprising an alkali or alkaline earth metal compound.

[0010] In the art, focus has been also made on solutions solely employing chemical compounds, including enzymes, avoiding at the same time mechanical abra sives. These solutions have, however, also several drawbacks including the availability and/or costs of the chemicals, possible health and/or environmental problems, including hazard to water organisms, and handling. Furthermore, the treated textile may encompass residues of the employed chemical compounds giving raise to textile changes, e.g.

yellowing, and/or health problems, such as allergic reactions.

[0011] US 5,914,443 A discloses for instance a method of manufacturing a fab ric or a garment with a stone-washed or worn look, the method comprising coating the yarn or fabric or garment with a polymer, such as a xyloglucan, prior to dyeing and afterwards creating the abraded or worn look by enzymatic degradation of said polymer using e.g. a xyloglucanase.

[0012] The present invention seeks to overcome the above mentioned prob lems by providing a washing process for producing a wash out effect in a textile and an abrasive for producing a wash out effect at a textile. Another objective is the provision of a washing process for producing a wash out effect in a textile and an abrasive effective in producing a regular wash out effect over the entire textile, wherein the degree of the wash out effect may be easily controlled by the washing process, including particularly duration of the treatment. Still another objective is the provision of a washing process for producing a wash out effect in a textile and an abrasive wherein the abrasive does not crumble, is reusable and is essentially not soaked with water and/or additives after the washing process. A further objective is the provision of a washing process for producing a wash out effect in a textile and an abrasive wherein the amount of waste, e.g. used pumice, water, particularly sewage water, and of possibly dangerous washing additives is reduced. Still a further objective is the provision of an abrasive which may be easily produced and which may be easily handled, particularly during a washing process for producing a wash out effect in a textile.

[0013] The above mentioned problems have been solved by providing a wash ing process for producing a wash out effect in a textile. The method comprises or consists of washing a textile in a washing machine, wherein the washing machine is loaded with the textile and at least one abrasive, wherein the abrasive comprises or consists of a rope comprising a first end section with a first rope end, a second end section with a second rope end, and at least one knot, the at least one knot being formed between the first end section and the second end section of the rope, wherein the at least one knot has a first intersection point, at which the first end section protrudes from a first loop which is made by the knot, and a second intersection point, at which the second end section protrudes from a second loop which is made by the knot, wherein a length L1 of the first end section is defined by a first distance between the first intersection point and the first rope end and a length L2 of the second end section is defined by a second distance between the second intersection point and the second rope end, wherein the length L1 of the first end section is L1 < 3.0 cm and the length L2 of the second end section is L2 < 3.0 cm, wherein a thickness T of the rope is 0.5 cm < T < 3.0 cm.

[0014] Furthermore, the above mention problems have been solved by provid ing an abrasive for producing a wash out effect at a textile. The abrasive comprises or consists of a rope comprising a first end section with a first rope end, a second end section with a second rope end, and at least one knot, the at least one knot being formed between the first end section and the second end section of the rope, wherein the at least one knot has a first intersection point, at which the first end section protrudes from a first loop which is made by the knot, and a second intersection point, at which the second end section protrudes from a second loop which is made by the knot, wherein a length L1 of the first end section is defined by a first distance between the first intersection point and the first rope end and a length L2 of the second end section is defined by a second distance between the second intersection point and the second rope end, wherein the length L1 of the first end section is L1 < 3.0 cm and the length L2 of the second end section is L2 < 3.0 cm, wherein a thickness T of the rope is 0.5 cm < T < 3.0 cm.

[0015] The present invention furthermore provides using a rope as a mechani cal abrasive, preferably in a washing process. The rope comprises a first end section with a first rope end, a second end section with a second rope end, and at least one knot, the at least one knot being formed between the first end section and the second end section of the rope, wherein the at least one knot has a first intersection point, at which the first end section protrudes from a first loop which is made by the knot, and a second intersection point, at which the second end section protrudes from a second loop which is made by the knot, wherein a length L1 of the first end section is defined by a first distance between the first intersection point and the first rope end and a length L2 of the second end section is defined by a second distance between the second intersection point and the second rope end, wherein the length L1 of the first end section is L1 < 3.0 cm and the length L2 of the second end section is L2 < 3.0 cm, wherein a thickness T of the rope is 0.5 cm < T < 3.0 cm.

[0016] The present inventors have found that the present abrasive is highly ef fective for producing a regular wash out effect over the entire textile. The present abrasive is easy to prepare and handle and comprises or consists of a rope of a particular thick ness, wherein the rope has a knot formed therein in such a manner that both end sections of the ropes are rather short, i.e. protrude either only a for a short distance from the knot of about 3 cm or less or finish within the knot’s loop, i.e. at a distance of about 0 cm. Said abrasive may be reused in a plurality of washing processed, such as 100 or more washing processes, without detectable decomposition thereof, such that no residues are left to be removed from the textile and the equipment. The present abrasive furthermore assists in reduced water consumption for the washing process and brings about a diminished consumption of additives, such as detergents and chemical abrasives, as well as the accompanying difficulties in handling and/or environmental problems. Since the present abrasive does not get soaked with washing liquid, it may be finally discarded as house hold waste.

[0017] Without wishing to be bound by any theory, it is presently assumed that the knot-shape of the present abrasive, in particular the arrangement/running direction of the rope at the knot's surface, assists in the beneficial wash out effects. The shape of the abrading exterior surface, particularly the exterior surface of the knot, influences the abrasive's movement and enables a continuous (spatial) rearrangement of the abrasive along the running direction of the rope. This contributes to an optimal positioning of the abrasive in an operated washing machine, i.e. during agitating and/or spinning, in the presence of textile, water and optionally other additives.

[0018] In other words, it is assumed that the overall shape as well as the sur face structure of the present additive in conjunction with the rope's dimension affords or at least contributes to an equal abrading effect by enabling a gentle and regular abrading contact of the abrasive and the textile. In contrast thereto, other known flexible or solid mechanical abrasives do not produce an equal wash out effect, i.e. result in a compara tively high number of defective goods.

[0019] The thickness of the rope and the ends thereof protruding only for a short distance from the knot further confer the present abrasive the required size in comparison to the dimensions of washing drum and/or textiles, which is about 3 to 10 cm, such as 5 to 8 cm, in its greatest dimension, its high mechanical stability and a rather "compact" consistency with a little tendency for soaking water and/or additives contained therein. A rope end L1 and/or L2 exceeding 3.0 cm has been furthermore found to nega tively impact the performance of the present abrasive in terms of providing an equal wash out effect to the textile and damaging the textile to a degree that it has to be discarded.

[0020] It must be furthermore assumed that a higher number, such as five or more, of comparatively thin ropes, having for instance each a thickness of less than 0.5 cm, such as less than 0.4 cm or less than 0.3 cm, which are arranged in parallel and formed to a knot are less stable due to breaking and/or frazzling of the individual thin ropes which is at least favored by chafing of the ropes against each other.

[0021] The expression "washing process" as used herein refers to a method of cleaning textile, which is usually performed with water and optionally soap and/or deter gent. The washing process may also encompass further additives which are usually used for augmenting the cleaning effect, such as detergents and enzymes, and/or obtaining a specific effect, such as bleaching agents.

[0022] The expression "wash out effect", as used herein refers to any abrasion provided to a textile. As used herein, "abrasion" includes physical, particularly mechanical, removal and/or chemical removal of portions of the fabric surface and/or the dyes by contact between the abrasive and the textile. The "wash out effect", for example, in the case of an indigo dyed denim textile, provides the textile a white on blue contrast appear ance. [0023] The term "textile" or "fabric" refers usually to sewn or unsewn fabrics, in cluding knits and woven fabrics, made of for instance from pure cotton or cotton blends. The textile may pertain, however, to any fabric made of natural and/or synthetic fibers.

[0024] Cotton and cotton blends are preferred. When cotton blends are em ployed, the amount of cotton in the fabric should be at least about 40 percent by weight, such as at least 50 percent by weight, at least 60 percent by weight, at least 70 percent by weight, at least 80 percent by weight, or at least 90 percent by weight, cotton. When employed as blends, the companion material employed in the fabric can include one or more non-cotton fibers including synthetic fibers particularly polyamide fibers, acrylic fibers, polyester fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, polyurethane fibers, polyurea fibers and aramid fibers. The textile typically has been colored with dye or pigment, for instance with the dye indigo.

[0025] Exemplary textiles include garments, such as jeans and skirts, particu larly denim jeans and skirts sweaters, hats, caps, purses, and any other objects made of synthetic and/or natural fabric. The present invention is applicable to any fabric article. A garment may be also referred to as a textile piece.

[0026] The term "additive" as used herein pertains to any chemical ingredient(s) used in a washing process. It will be understood that the use of additive(s) is optional and the particular chemical composition thereof, if used, depends upon the type of wash out effect, particularly stone washing effect, desired. These additives may for instance provide a chemical reaction to aid or effect the abrasion. The additive may contain strong oxidiz ers, such as potassium permanganate or sodium hypochlorite, which gradually oxidize and destroy the color in usually in the areas where the mechanical abrasive contacts the textile. The skilled person is aware about the concentration of such strong oxidizers as well as alternative compounds providing the same effect.

[0027] Other additives comprise detergents, dyes, enzymes, lubricants, dye fix atives, organic and polymeric anti-redeposition agents, such as sodium carboxymethyl cellulose, polyvinylpyrrolidone, and polyacrylates; anionic suspending agents; and organic chelating agents, such as ethylene diamine tetraacetic acid (EDTA), nitrilotriacetic acid and salts thereof.

[0028] Particularly, the use of an anti-redeposition agent or antibackstaining agent as an additive is preferred. Said antibackstaining agent emulsifies and carry away particles of dye, fabric, etc. which are abraded from the fabric and suspended in the rinse liquid, while chelating agents complex water hardness, heavy metal ions and some of the by-product components which may be released from the stone compositions. One skilled in the art may readily determine the type and amount of additional ingredients to be added to the chemical stonewash composition based on this disclosure and the fabric treatment desired.

[0029] The additives may be provided in any application form including for in stance tablets, powders or liquid. Depending on the application form further compounds, such as processing aids, binders, solvents and the like may be included. Suitable binders may include benzoic acid fatty compounds, acrylates, polyvinyl alcohols and silicates, may also be used to increase the integrity or stability of the tablets. In addition to the ingredi ents referred to above, also other processing chemicals may be included, such as bleach es, acids, fabric softeners, overbleaches, etc., depending upon the fabric treatments desired. Thus, bleaching or acid washing of the fabric may be carried out simultaneously with the washing process by incorporating the necessary chemicals.

[0030] A "rope" as used herein refers to a group of yarns, plies, fibers or strands that are usually twisted or braided together into a larger and stronger form. The rope is in common thicker and stronger than similarly constructed cord, string, and twine. The rope furthermore exhibits sufficient flexibility that at least one knot may be formed therein.

[0031] The rope may be constructed of any long, stringy, fibrous material, but is generally made from any natural and/or synthetic fibers. Exemplary natural fibers include one or more of hemp, linen, cotton, coir, jute, straw, and sisal. Exemplary synthetic fibers include one or more of polypropylene, nylon, polyesters (e.g. PET, LCP, and Vectran), polyethylene (e.g. Dyneema and Spectra), Aramids (e.g. Twaron, Technora and Kevlar) and acrylics (e.g. Dralon). Other fibrous materials such as silk, wool or rayon may be employed as well. The fibers may be made of mixtures of several fibers or by using co polymer fibers. Also fibers of a core-shell structure may be employed.

[0032] The rope preferably does not encompass any metal component at the rope's surface, such as a metal wire. It is, however, conceivable that a rope is employed which comprises a metal component within the rope, such as a metal wire extending at the rope's center, without exposing the wire's ends at the rope's ends, such as by provid ing a polymer cap on the rope's end.

[0033] The present rope is preferably entirely made of synthetic fibers due to their increased strength, resistance to rotting, and water repellence in comparison to natural fibers. More preferably, the rope is made of a synthetic recycling material, which has been found providing sufficient characteristics, such as strength, and is available in abundant amounts. The synthetic recycling material may be a blend of different plastic materials or a specific plastic material, such as polypropylene or polyethylene.

[0034] The present rope exhibits a diameter or thickness T of 0.5 to 3.0 cm, such as 0.75 to 2.75 cm, 1.0 to 2.5 cm, 1 .25 to 2.25 cm, 1.5 to 2.0 cm or 1.75 to 1.8 cm. Preferably, the rope has a constant thickness.

[0035] "A rope" may furthermore pertain to any number of ropes, such as one, two, three, four, five or more ropes arranged in parallel. "A rope" may also pertain to a multiplied, e.g. doubled or tripled, rope in which different sections of the rope have been aligned in parallel before making a knot therein. This has the advantage that the number of rope ends may be reduced. It is furthermore preferred to employ a rope which is provided in form of a closed loop or ring, i.e. a rope without having any end.

[0036] The lengths L1 and L2 of the first and second end sections are inde pendent from each other < 3 cm, such as 0 to 2.5 cm, 0.25 to 2.0 cm, or 0.5 to 1 .0 cm. These lengths L1 and L2 assist on the one hand in preventing untying the knot (particular- ly with regard to longer ends, in particular to an end having a length of more than 3 cm) and furthermore define the overall length of the rope, which is usually in the range of from 10 cm to 30 cm, such as 15 cm to 27.5 cm, 20 cm to 25 cm, or 22 cm to 24 cm. It will be understood that the exact length of the rope depends on various parameters, including the thickness of the rope, its flexibility, and the number and type of the knots employed.

[0037] A "knot" as used herein refers in its broadest sense to any intentional complication in a rope and which is established only by the rope. Any further stabilization means, such as a glue, does therefore not form part of the knot as such, but may be present as an auxiliary component. Furthermore, the knot preferably does not surround and/or is formed around any object. More preferably, the knot does not interconnect the rope to any other object, including another rope.

[0038] It will be appreciated that the rope comprises a material which exhibits a sufficient hardness for abrading a textile. In general, each material which exhibits a greater hardness than the textile to be subjected to abrasion may be employed. The material preferably has a shore D hardness of about 50 or more, such as 52 to 90, 54 to 80, 56 to 70, 58 to 76, 60 to 74, or 62 to 64, which is more preferably determined accord ing to DIN ISO 7619-1 (2012-02) and DIN EN ISO 868 (2003-10). The fiber structure of the rope may also add roughness.

[0039] A preferred type of knot is a "stopper knot" or "stopper" usually used for creating a fixed thicker point on an otherwise-uniform thickness rope for the purpose of preventing unreeving by stopping the rope at that point from slipping out of a narrow passage, i.e. the first and second loops.

[0040] Exemplary stoppers include an overhand knot, including a single, double or triple overhand knot, a figure-eight knot or a figure-of-eight knot, a stevedore knot and an Ashley’s stopper knot. The stopper knots are particularly preferred since they may be easily made while avoiding additional complexity to the knot in terms of adding several rope portions over each other in forming the knot, which increases the largest diameter of the present abrasive in comparison to thickness T of the rope. Accordingly, it is preferred that other types of knots than stoppers, including for instance decorative knots and/or knots for interconnecting the ends of two or more ropes together, are not used.

[0041] A particularly preferred stopper is an overhand knot. The overhand knot becomes a trefoil knot by joining the ends thereof in an abutting manner, e.g. by intercon necting, such as gluing, the rope's end faces together. It may be assumed that the trefoil knot represents the best possible knot for the present abrasive.

[0042] It will be appreciated that the knot needs to be sufficiently tightened to be prevented from untightening/losing in course of the washing process. Sufficiently tightening of the knot may be performed by a machine or the pulling force of an adult human according to DIN 3341 1 , involving for instance a pulling force of about 180 N or more, such as 190 N to 500 N, such as 200 N to 400 N, 220 N to 300 N, or 240 N to 250 N. The present abrasive may be therefore prepared by fixedly attaching one end of a rope while applying human pulling force to the other end, followed by cutting the ropes end to the required lengths L1 and L2.

[0043] "Agitating" is intended to describe a low speed providing continuous mix ing of the washing drum's interior. The low speed preferably refers to a speed of about 1 to about 8 rpm, such as 2 to 7 rpm, 3 to 6 rpm or 4 to 5 rpm, if not specifically mentioned otherwise. In contrast thereto, "centrifuging" or "spinning" refers to a high speed of about 800 rpm to about 1500 rpm, such as 900 rpm to 1400 rpm, or 1000 to 1200 rpm, if not specifically mentioned otherwise.

[0044] The expression "essentially" as used herein refers in general to a small deviation, preferably a deviation of ± 10 % or less, such as ± 5 % or less, or ± 1.0 % or less. "Essentially round" or "essentially spherical" thereby indicates that the diameter of the object may vary by e.g. ± 10 % or less.

[0045] According to a preferred embodiment of the present invention wash out effect is a stone washing effect. [0046] The mechanical abrasion of a textile, particularly of a dyed denim textile, in a washing process is also referred to as "stone washing". The stone washing effect usually not only depends on the type of the textile and employed mechanical abrasive but may also depend on an optional additive, which provides a chemical reaction to aid the abrasion and/or bleaches the textile. Such a compound which aids the abrasion or which bleaches the textile is preferably an oxidizer. Examples of preferred oxidizers included one or more of hydrogen peroxide (alone or in combination with a suitable enzyme, such as a catalase), a hypochlorite, such as potassium or sodium hypochlorite, and a perman ganate, such as potassium or sodium permanganate. The concentrations of said oxidizers are known to the skilled person.

[0047] Methods for imparting a stonewashed appearance to textiles are gener ally described in US 4,832,864, which is incorporated herein by reference in its entirety.

[0048] According to another preferred embodiment of the present invention, the washing process is conducted with at least one denim textile.

[0049] Any numbers of textiles, in particular denim textiles, such as 10 or more textile pieces, 25 or more textile pieces, 50 or more textile pieces, or 60 or more textile pieces, may be simultaneously subjected to the present washing process.

[0050] "Denim" or "Serge de Nimes" as used herein refers usually to a cotton warp-faced textile in which the weft passes under two or more warp threads. This twill weaving produces a diagonal ribbing that distinguishes it from cotton duck. The denim is preferably indigo denim or, in which the warp thread is dyed with indigo, while the weft thread is left white. As a result of the warp-faced twill weaving, one side of the textile is dominated by the blue warp threads and the other side is dominated by the white weft threads.

[0051] According to still another preferred embodiment of the present invention the washing process includes one ore more of (i) a washing step with an antibackstaining agent and/or a detergent, (ii) adding of one or more of NaOCI, KMn0 ₄ , a peroxide- cellulase-mixture, and (iii) optionally adding a compound for removal of KMn0 ₄ Mn0 ₂ residues.

[0052] A dye, as it is removed from the textile, any post treatment with e.g. a cellulase or in course of conventional washing process may cause "back staining" or "re deposition" on the denim material. In case of e.g. a indigo dyed textile, in particular a denim textile, re-coloration of blue threads and blue coloration of white threads takes place which results in an undesired reduced contrast between the blue and white threads.

[0053] Back staining is usually caused by the formation of glucose during the washing process of textile. The glucose act as reducing agent and facilitates the dye, in particular the indigo dye, to exist on the white part of the textile, thus reducing the contrast of the textile.

[0054] In order to avoid such back staining, which reduces the value of the tex tile, an "antibackstainer", "antibackstaining agent" or“redepositing agent” are used in the wash bath. These agents are added in the bath along with other chemicals associated with the respective washes. These agents are capable of prohibiting the action wherein the removed dyes re-deposit themselves on the garment. Such antibackstaining agents are well known in the art and mostly comprise three substances, a dispersing agent, a chelating agent, and an emulsifying agent. All these must be of a particular concentration in order to inhibit the adherence of e.g. indigo dyes on the white portions of denim gar ments. Most of these anti back staining agents are highly efficient in soft water, but in hard water they might be less effective and so the dyes will re-deposit. Antibackstaining agents may also contain sequestering/ complexing agents, such as EDTA, salts of EDTA, citric acid, and salts of citric acid, so that they can be used in hard water. Acid liberating agents may be also used along with antibackstaining agents to reduce the alkaline conditions and enhance the enzyme activity.

[0055] Antibackstaining agents may be made from polyglycol ether derivatives and polymer phosphates. Alternatively or in addition, enzymes may be used, such as cutinase and other lipolytic enzymes. [0056] Another way of avoiding back staining is by using week oxidizing agents, such as hydrogen peroxide, hypo chlorites, permanganates, peroxides, etc. There are some mild oxidizing agents also, which are called resist salts. These week oxidizing agents will act on the glucose and decrease its reducing power and prevent back staining. These week oxidizing agents and the use thereof is well known to the skilled person.

[0057] The detergent mixture may be any common available washing detergent intended for washing machines.

[0058] According to a preferred embodiment of the present invention, the wash ing process is free from any further mechanical abrasive.

[0059] Hence, merely one or more of the present abrasives are used. Further, mechanical abrasives, such as stones of natural or synthetic origin, wood, sand, rubber pieces, glass pieces, and polymeric foams are not employed. In this context, the mechan ical abrasive needs to be distinguished from other compounds possibly contained in the washing process. For instance, if a washing detergent is employed said washing deter gent may encompass fillers which may have the same chemical structure as synthetic stones. As explained above, the mechanical abrasives of the art require a certain size for exerting their activity in that the mechanical abrasives have an individual size in the macroscopic range, of e.g. having a greatest dimension of 0.5 cm or more, such as 1.0 cm or more, 2.0 cm or more, 3.0 cm or more, 4.0 cm or more, or 5.0 cm or more.

[0060] More preferably, the present washing process is also free from any chemical abrasive.

[0061] It will be understood that "free from any chemical abrasive" does not necessarily mean that, for instance, no oxidizers or merely specific oxidizers are em ployed. "Free from any chemical abrasive" has rather the meaning that such chemical abrasive may be present but in a concentration which does not bring about a detectable washing out effect, such as a chemical abrasive in a concentration for preventing and/or inhibiting backstaining. [0062] According to another preferred embodiment of the present invention, the rope has one two or three knots.

[0063] Preferably one or two knots are employed. More preferably, a single knot is employed. The use of less knots assists in improved functioning of the present abrasive due to an improved relationship between the dimensions of the rope, the overall size of the knot, including a greatest dimension of about 2.0 to 10.0 cm, the shape of the knot, which is essentially spherical or essentially ovoid, and the spatial arrangement of the rope at the knot's surface. As already noted above, all said parameters are believed to assist to the present beneficial effects of the present abrasive.

[0064] According to still another preferred embodiment of the present invention the at least one knot is a stopper knot selected from the group consisting of an overhand knot, a figure-eight knot, a stevedore knot, an Ashley's stopper knot, an offset overhand bend (which corresponds to an overhand knot employing two ropes) and a reef knot.

[0065] As noted above, knots of "simply structure", such as stoppers, assist in the beneficial effects of the present abrasive. Out of these knots overhand knot, a figure- eight knot, an offset overhand bend and a reef knot have been proven particularly useful. More preferably, an overhand knot, in particular a single overhand knot are employed.

[0066] According to a preferred embodiment of the present invention wherein the first rope end and the second rope end are secured against defibring.

[0067] Preventing defibring assists in longer lifetime of the present abrasive, in cluding the use of the present abrasive in a higher number of washing processes, such as more than 100 or more than 150.

[0068] Defibring of the rope ends may be prevented by a number of measures alone or in combination, including for instance one or more of melting (together) of the ends of synthetic fibers; providing a glue, e.g. a thermoplastic glue, on the first and second rope ends; providing a plastic end cap, which may be made of the same or different material than the rope, on the first and second rope ends; providing a plastic cable tie around each of the first and second rope ends and a plastic cable tie around both rope ends at the same time, thereby connecting the rope ends in parallel.

[0069] According to another preferred embodiment of the present invention first rope end and the second rope end are connected together in parallel.

[0070] For instance, a plastic cable tie is provided around both rope ends at the same time, thereby connecting the rope ends in parallel. This has been proven a sufficient measure for preventing defibring and is particularly preferred due to its simple and fast implementation.

[0071] According to still another preferred embodiment of the present invention, the length L1 of the first end section is L1 < 1 .0 cm, and the length L2 of the second end section is L2 < 1.0 cm.

[0072] According to a preferred embodiment of the present invention the rope is made from a recycled plastic material.

[0073] Such a recycled plastic material may be made of polypropylene and/or polyethylene. Recycled plastic material is an abundant and well available base material.

[0074] According to another preferred embodiment of the present invention, the rope comprises or consists from one or more materials selected from the group consisting of aramid, polyester, polyamide, polypropylene, polyethylene and poly(p- phenylene-2,6-benzobisoxazole). Exemplary other materials are either noted above and/or are well known in the art.

[0075] According to still another preferred embodiment of the present invention, the rope has a round or ellipsoid cross-section. [0076] It will be understood that the shape of a rope, usually made of a plurality of fibers, is determined by the individual fibers in that the cross-section is rather essential ly round or essentially ellipsoid. In case of an ellipsoid cross section, the thickness T corresponds the length L(ma) of the major axis, wherein the minor axis has a length L(mi) fulfilling the criteria 0.5 x L(ma) < L(mi) < L(ma) provided that L(mi) > 0.5 cm.

[0077] The invention will now be illustrated in further detail by reference to the following specific, non-limiting figures and examples.

[0078] In the figures shows

[0079] figure 1 a schematic drawing of an abrasive according to the present in vention including a single overhand knot;

[0080] figure 2 a schematic drawing of an abrasive according to the present in vention including an overhand knot with both rope ends connected in parallel;

[0081] figure 3 a schematic drawing of an abrasive according to the present in vention including a monkey's fist;

[0082] figure 4 a schematic drawing of an abrasive according to the present in vention including a figure-of-eight; and

[0083] figure 5 a schematic drawing of an abrasive according to the present in vention including a single overhand knot formed by two ropes aligned in parallel.

Examples

Example 1 [0084] In a washing process the drum of a Macar washing machine (industrial washing machine) has been loaded with 60 indigo dyed denim trousers. All steps have been performed with slow mixing agitating at a speed of about two to three rotations per minute.

[0085] Five abrasives according to the present invention (described with refer ence to Fig. 1 ), 600 g Rospers TMS plus Lycra (CAS 1 13669-97-9, Royal chemicals) and 600 g Royazyme SC750 concentrate (CAS 9012-54-8, Royal chemicals) in 500 I water have been added and agitated at low speed at a temperature of 25°C for 45 minutes, centrifuged at 800 rpm for 5 minutes. The liquid has been removed and the textile pieces have been rinsed with 500 I water and discarding the liquid.

[0086] Fig. 1 shows a schematic drawing of the above mentioned abrasive for producing a wash out effect at a textile. A rope 10 having a round cross section and a constant thickness of 2 cm is made of recycled polypropylene. One end of the rope 10 has been fixedly attached to a surface and a single overhand knot has been formed therein providing the knot 20. The knot 20 has been tied by human pulling force of approx. 200 to 250 N. Subsequently the first end section 12 and second end section 16 have been formed by cutting the rope (essentially orthogonal to the running direction of the rope) at lengths L1 and L2 of 0.5 cm, respectively, from the first intersection point 22, at which the first end section 12 protrudes from a first loop 24 which is made by the knot 20, and a second intersection point 26, at which the second end section 16 protrudes from a second loop 28 which is made by the knot 20. The first and second end sections 12, 16 have been melted, respectively, using a cigarette lighter.

[0087] Subsequently 30 I of 15 wt.-% NaOCI solution (Koruma, Klor Alkali) and 400 g Na ₂ C0 ₃ (Sisecam, Hafif Soda) have been added in 500 I water and agitated at 50°C for 50 minutes, followed by removing the liquid and rinsing with 1 ,0 I Antiper (Cas. No. 9001 -05-02, Royal Chemicals) and 2 I of 50 wt.-% H ₂ 0 ₂ (Cas. No. 7722-84-1 , Royal Chemicals) in 500 I water at 25°C for 5 minutes. The liquid has been discarded. [0088] Another rinsing step with 500 I of water has been performed. 5 g K ₂ Mn0 ₄ (Cas. No. 7722-64-7) have been added thereto, followed by adding 600 g Rospers TMS plus Lycra (CAS 1 13669-97-9, Royal chemicals) and 250 g Roge Con Mex (Kaiser Tekstil) and agitating at 25°C for 5 minutes.

[0089] Finally, the textile pieces have been rinsed another time with 500 I water and dried.

[0090] The 60 textile pieces exhibit an equal abrasive effect over the entire sur face. No visible damages to any textile piece is visable. Synthetic fibers or traces thereof originating from the present abrasives have not been found at/in textile pieces.

[0091] 50 times reusing the abrasives did not result in any visable damage to the abrasives. Some plastic reminders presumably originating from the synthetic fibers have been located in the sieve of the washing machine. No other plastic reminder has been detected in the equipment.

[0092] 150 times reuse resulted still in functional abrasives having, however, a consumed look. However, no plastic reminders have been detected in the equipment.

[0093] No substantial uptake of washing solution in the present abrasive was detected such that the abrasives were immediately reused after finishing of a washing process. Approximately 1000 I of waste water have been treated in a sewage plant and reused.

Example 2

[0094] The example 2 has been performed as outlined in example 1 above with the proviso of substituting the abrasives according Fig. 1 by the same number of abra sives according to Fig. 2. [0095] Fig. 2 shows the schematic drawing of the abrasive for producing a wash out effect at a textile. The abrasive has been prepared according to Fig. with excep tion of providing the lengths L1 and L2 with 3.0 cm, respectively, and interconnecting the same in parallel at a distance of about 0.1 cm to 0.5 cm from the rope ends 13, 18 (with the ends of the rope 10 facing away from the knot 20) with a plastic cable tie (which has been tied by human pulling force of approx. 200 to 250 N using tongs and removing protruding plastic reminders).

[0096] The same results as indicated in example 1 above have been obtained with the proviso also that no plastic reminders have been found in the sieve of the wash ing machine at any time and that the present abrasives exhibited after 150 times reuse a less consumed look than the abrasives of example 1 .

Example 3

[0097] The example 3 has been performed as outlined in example 1 above with the proviso of substituting the abrasives according Fig. 1 by the same number of abra sives according to Fig. 3.

[0098] Fig. 3 shows a schematic drawing of another abrasive for producing a wash out effect at a textile. The rope has a thickness of 0.5 cm forming a "monkey's fist" or "monkey paw". The lengths L1 and L2 are 0.5 cm, respectively. Preparing the knot has been performed as indicated with respect to fig. 1 above.

[0099] It has been found that this ornamental knot also provides acceptable re sults, even though the results are not equally good as in case a stopper is employed. In this respect it has to be noted that most textile pieces offered an equal worn effect.

However, two textile pieces exhibited minor damages to the tissue. Furthermore, the rather thin rope made from recycled polypropylene tends to consume more fast than thicker ropes thereby offering a reuse number which is lower than that of a stopper. It may be assumed that the exposed surface portions of the rope, which are partially orthogonal to each other, impede proper arrangement of the abrasive within an operated washing machine.

Examples 4 and 5

[00100] The examples 4 and 5 has been performed as outlined in example 1 above with the proviso of substituting the abrasives according Fig. 1 by the same number of abrasives according to Fig. 4 and 5, respectively.

[00101 ] Figs. 4 and 5 show schematic drawings of another abrasive for produc ing a wash out effect at a textile (Fig. 4, figure-of-eight, Fig. 5 a single overhand knot employing two ropes 10 in parallel, wherein the ropes are made of the same material and having the same thickness). The ropes of Figs. 4 and 5 are identical to that of fig. 1 and the knot has been prepared in the same manner.

[00102] Similar results as outlined for example 1 above have been obtained.

Comparative example

[00103] The comparative example has been performed as outlined in example 1 above with the proviso of substituting the abrasives according to the present invention by 50 kg of pumice stones. The pumice is provided in pieces having an essential spherical form and a size between table tennis and tennis ball size (wherein the size deviation of an individual piece is approx. ± 8 %).

[00104] The comparative example exhibited the problems of small pumice piec es of generally 0.2 mm (greatest dimension) with bags and other parts of the textile pieces, whereas larger pumice pieces of a size about 0.3 mm to 1 .0 cm (greatest dimen sion), which potentially destroy the equipment, were not detected. The small pumice pieces have been washed out in course of a further washing step using 500 I water. The reminders of the pumice have been collected and discarded as hazardous waste. Approx imately 1500 I of waste water have been treated in a sewage plant and reused. Further preferred embodiments

[00105] Further preferred embodiments of the present invention may be derived from the clauses outlined hereinafter.

[00106] Clause A1. Washing process for producing a wash out effect in a textile, comprising or consisting of washing a textile in a washing machine, wherein the washing machine is loaded with the textile and at least one abrasive, wherein the abrasive com prises or consists of a rope comprising a first end section with a first rope end, a second end section with a second rope end, and at least one knot, the at least one knot being formed between the first end section and the second end section of the rope, wherein the at least one knot has a first intersection point, at which the first end section protrudes from a first loop which is made by the knot, and a second intersection point, at which the second end section protrudes from a second loop which is made by the knot, wherein a length L1 of the first end section is defined by a first distance between the first intersection point and the first rope end and a length L2 of the second end section is defined by a second distance between the second intersection point and the second rope end, wherein the length L1 of the first end section is L1 < 3.0 cm and the length L2 of the second end section is L2 < 3.0 cm, wherein a thickness T of the rope is 0.5 cm < T < 3.0 cm.

[00107] Clause A2. Washing process according to clause A1 , wherein the wash out effect is a stone washing effect.

[00108] Clause A3. Washing process according to clause A1 or A2, wherein the washing process is conducted with at least one denim textile.

[00109] Clause A4. Washing process according to any of clauses A1 to A3, wherein the washing process includes one ore more of (i) a washing step with an anti- backstaining agent and/or a detergent, (ii) adding of one or more of NaOCI, KMn0 ₄ , a peroxide-cellulase-mixture, and (iii) optionally adding a compound for removal of KMn0 ₄ Mn0 ₂ residues. [00110] Clause A5. Washing process according to any of clauses A1 to A4, wherein the washing process is free from any further mechanical abrasive, more prefera bly wherein the washing process is free from a chemical abrasive.

[00111 ] Clause B1. Abrasive for producing a wash out effect at a textile, the abrasive comprising or consisting of a rope comprising a first end section with a first rope end, a second end section with a second rope end, and at least one knot, the at least one knot being formed between the first end section and the second end section of the rope, wherein the at least one knot has a first intersection point, at which the first end section protrudes from a first loop which is made by the knot, and a second intersection point, at which the second end section protrudes from a second loop which is made by the knot, wherein a length L1 of the first end section is defined by a first distance between the first intersection point and the first rope end and a length L2 of the second end section is defined by a second distance between the second intersection point and the second rope end, wherein the length L1 of the first end section is L1 < 3.0 cm and the length L2 of the second end section is L2 < 3.0 cm, wherein a thickness T of the rope is 0.5 cm < T < 3.0 cm.

[00112] Clause B2. Abrasive according to clause B1 , wherein the rope has one, two or three knots, preferably one knot.

[00113] Clause B3. Abrasive according to clause B1 or B2, wherein the at least one knot is a stopper knot selected from the group consisting of an overhand knot, a figure-eight knot, a stevedore knot, an ashley's stopper knot, an offset overhand bend and a reef knot.

[00114] Clause B4. Abrasive according to any of clauses B1 to B3, wherein the first rope end and the second rope end are secured against defibring.

[00115] Clause B5. Abrasive according to any of clauses B1 to B4, wherein the first rope end (14) and the second rope end are connected together in parallel. [00116] Clause B6. Abrasive according to any of clauses B1 to B5, wherein the length L1 of the first end section is L1 < 1 ,0 cm and the length L2 of the second end section (16) is L2 < 1 ,0 cm, preferably wherein the length L1 of the first end section is 0.1 cm < L1 < 1 ,0 cm and the length L2 of the second end section (16) is 0,1 cm < L2 < 1 ,0 cm .

[00117] Clause B7. Abrasive according to any of clauses B1 to B6, wherein the rope is made from a recycled plastic material, preferably wherein the rope is made from recycled polypropylene and/or recycled polyethylene.

[00118] Clause B8. Abrasive according to any of clauses B1 to B7, wherein the rope comprises or consists from one or more materials selected from the group consisting of aramid, polyester, polyamide, polypropylene, polyethylene and poly(p-phenylene-2,6- benzobisoxazole).

[00119] Clause B9. Abrasive according to any of clauses B1 to B8, wherein the rope has a round or ellipsoid cross-section.

[00120] Clause C. Using a rope as a mechanical abrasive, preferably in a wash ing process, the rope comprising or consisting of a first end section with a first rope end, a second end section with a second rope end, and at least one knot, the at least one knot being formed between the first end section and the second end section of the rope, wherein the at least one knot has a first intersection point, at which the first end section protrudes from a first loop which is made by the knot, and a second intersection point, at which the second end section protrudes from a second loop which is made by the knot , wherein a length L1 of the first end section is defined by a first distance between the first intersection point and the first rope end and a length L2 of the second end section is defined by a second distance between the second intersection point and the second rope end, wherein the length L1 of the first end section is L1 < 3.0 cm and the length L2 of the second end section is L2 < 3.0 cm, wherein a thickness T of the rope is 0.5 cm < T < 3.0 cm.