A Dispersion, Uses, Methods, Apparatuses, a Washing Line and a Fabric Web Manufacturing Line for Washing a Textile Web with Bentonite Clay

The invention relates to a dispersion for washing a fabric web. The invention also relates to a use of such dispersion for washing a fabric web and in general to the use of bentonite clay for washing a fabric web. The invention also relates to methods for washing a fabric web with a dispersion comprising bentonite clay. The invention also relates to apparatuses for continuously washing a fabric web. The invention also relates to a washing line comprising a plurality of apparatuses for continuously washing a fabric web. The invention also relates to a fabric web manufacturing line for coloring and washing a fabric web. The invention also relates to uses of such apparatuses, washing lines and/or fabric web manufacturing lines. The invention also relates to methods for washing and optionally coloring a fabric web according to the operation of such apparatuses, washing lines and/or fabric web manufacturing lines. Finally, the invention relates to fabric webs being washed with bentonite clay, with the inventive dispersion and/or according to one of the inventive methods or uses. Additionally, the invention relates to a fabric web being washed according to the operation of one of the inventive apparatuses and/or according to the operation of the inventive washing line. Finally, the invention relates to a fabric web being colored and washed according to the operation of the inventive fabric web manufacturing line.

Fabric webs are subjected to a plurality of substances during their manufacturing. In this regard, the manufacturing of a fabric web inter alia comprises pre-treatment of the fabric and coloring of the fabric. Pre-treatment can for instance comprise desizing, scouring, mercerizing and/or bleaching which can all encompass subjection of substances, in particular chemicals, to the fabric web. For instance, desizing is used for removal of warp size on fabric web by solubilization. Thereby, starch- based sizes are removed by acid hydrolysis or by rot steeping or by enzymatic treatment. Scouring is used for removal of hydrophobic traces like oils, waxes, pectins, proteins and so forth from cellulostic cotton in order to improve its absorbency and reactivity with chemicals and dyes in further processing. Scouring can be conducted by boiling treatment with alkali, along with surfactants which convert many of the above hydrophobic residues to soluble fragments, which are washed and removed. In case of synthetic fibers like polyester, desizing and scouring can be accomplished by a single alkali boil. Mercerizing serves to impart strength, dimensional stability, luster and improved dye uptake of cotton and fastness. For this purpose, mercerizing can comprises the swelling of cotton by impregnation in caustic solution under tension. Bleaching serves for removal of natural coloring matter in cotton by subjecting a cotton fabric web to oxidative/reductive destruction of coloring matter and obtaining a better whiteness. Thereby, optical brightening agents can be added to improve whiteness.

In order to avoid that these substances being applied to the fabric web during pre-treatment, which can cause irritation on the skin of a person when wearing, e.g, clothes being manufactured from such fabric web, it is necessary to properly wash the fabric web after pre-treatment so as to remove the substances.

In addition, dyes, such as indigo dyes, being applied to a fabric web upon coloring, in particular upon dyeing, do usually not entirely bond on the fabric web. In order to avoid that unbound dye induces and/or triggers staining upon wearing a piece of clothing produced from the fabric web or during home washing, this unbound dye needs to be removed by at least one washing step after dying.

Well-known coloring methods are continuous coloring, in particular dyeing, and pad-batch coloring, in particular dyeing. Continuous coloring usually comprises a plurality of coloring basins through which the fabric web is continuously guided. While continuous coloring turns out to be advantageous in large scale production, it turns out to be inefficient for small size production. Accordingly, energy and fabric web material is wasted, wherein said energy and fabric web material is mainly wasted upon starting and ending the operation of the continuous coloring line.

For small and medium-sized production, the pad-batch method turns out to be advantageous. Contrary to the continuous coloring process, the pad-batch process only requires one coloring basin and, therefore, less space in a factory. Additionally, pad-batch coloring is characterized by less loss of energy and fabric web material upon starting and ending the coloring process. Another advantage of pad-batch coloring is that the color to be subjected to a fabric web can be changed faster and with less loss of energy as well as fabric web material.

Briefly, pad-batch coloring comprises the steps of unwinding the fabric web from a fabric roll, applying the dye to the fabric web, for instance by means of a Foulard, optionally sheeting the fabric web and rewinding the fabric web on a roll, and further optionally wrapping the fabric web with a film. Subsequently, the fabric web is stored for a desired time, in particular between 12 and 24 hours, at room temperature to allow the color to bond on the fabric web. During storage, the fabric web can be slowly rotated so as to enable uniform coloring results.

However, it has been found that a large amount of the dye, in particular about 40% of the dye, can be washed off during subsequent washing processes, because the dye is hydrolyzed. In order to avoid that this dye is washed off during home washes, thereby staining laundry being washed with pad-batch colored fabrics, or to prevent that pad-batch colored fabrics could stain a wearer’s skin, it is advisable to properly wash the fabric web after the storage.

In addition, a commonly used pre-treatment process before pad-batch coloring is bleaching. Therefore, also in order to avoid irritations on the wearer’s skin due to bleaching agent residues, it is advisable to properly wash a pad-batch colored fabric web. In order to achieve such proper washing, it is commonly known to wash pad-batch colored fabrics with soaping agents, such as anionic surfactants or acrylates. However, a huge drawback of these washing agents is that they contaminate the water to be used for washing which impairs the sustainability of the fabric web manufacturing process. Further, it has been found that commonly used soaping agents require high temperatures of about 9O°C to be effective which leads to high energy consumption of the washing process which further impairs the sustainability of the fabric web manufacturing process. Another problem of commonly-used soaping agents, which has been identified by the inventors of the present invention, is that they impair the color fastness to acid perspiration, the color fastness to alkaline perspiration and the color fastness to water of the colored fabric web. This problem has been found to be particularly dramatic in case of dark colored fabrics.

It is therefore an object of the invention to overcome the drawbacks of the prior art, in particular to provide a dispersion for washing a fabric web, uses, methods, apparatuses, a washing line and a fabric manufacturing line for washing a fabric web and fabric webs being processed with such dispersion and/or with such use, method, apparatus, washing line and/or fabric manufacturing line providing increased color fastness properties, decreased energy consumption and/or decreased water pollution.

The object is solved by the independent claims.

The above problem is solved in a first aspect by a dispersion for washing a fabric web, wherein the dispersion comprises bentonite clay, and wherein the dispersion does not comprise an anionic surfactant, a non-ionic surfactant and/or an acrylate.

The term “aciylate” within the meaning of the present invention may encompass salts, esters, and conjugate bases of acrylic acid, free acrylic acid (the protonated acid form), as well as polymers and copolymers thereof. Especially, acrylates as referred to herein may encompass polyaciylates (polymeric acrylates), that is, polymers of aciylic acid which are partially or fully deprotonated, in particular salts of polyacrylic acid, such as the sodium salt of polyaciylic acid, which are known as acrylates with anionic character.

A surfactant within the meaning of the present invention may be a compound that lowers the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. An anionic surfactant within the meaning of the present invention may especially be a surfactant containing one or more (for example one) anionic functional group (for example as a head group), such as sulfate, sulfonate, phosphate, and carboxylate, at their head, and further containing one or more (for example one) unpolar group (tail group) such as a hydrocarbon chain, which can be branched, linear, or aromatic, a partially or fully fluorinated hydrocarbon chain, or the like, wherein it may especially be provided that the unpolar group does not carry an (electric) charge, that is, is neither anionic nor cathionic. Non-ionic surfactants within the meaning of the present invention may be surfactants that have one or more (for example one) polar head group that is not electrically charged and further comprises one or more (for example one) unpolar group (tail group) as described above in detail with respect to the anionic surfactant. In the non-ionic surfactant, the polar head group may be an oxygen-containing hydrophilic group, such as a polyol, a polyethylene glycol, a derivative of ethanolamine and the like. The inventors found that a dispersion for washing a fabric web, wherein the dispersion comprises bentonite clay, and wherein the dispersion does not comprise an anionic surfactant, a non-ionic surfactant and/or an acrylate, solves the above problems of the prior art in a surprising manner. Importantly, comparing the properties of the commonly used soaping agent Albatex AD with a dispersion for washing a fabric web, wherein the dispersion comprises bentonite clay according to the first aspect of this invention, revealed the highly advantageous properties of said dispersion for washing a fabric web according to the present invention. In particular, when washing a fabric web with a dispersion comprising bentonite clay according to the present invention, color fastness properties after washing the fabric web are extensively enhanced. Moreover, the dispersion according to the first aspect of the invention can comprises bentonite clay in water only, and does not comprise any anionic surfactant, non-ionic surfactant and/or acrylate. This results in less contamination of water when washing with a dispersion for washing a fabric web according to the first aspect of this invention, compared to washing with commonly used soaping agents, which comprise anionic surfactants, non- ionic surfactants and/or acrylates. Accordingly, the sustainability of the fabric web manufacturing process using the dispersion for washing a fabric web according to the first aspect of this invention is strongly enhanced compared to commonly used soaping agents, that usually comprise an anionic surfactant, non-ionic surfactant and/or an acrylate.

Without being bound thereto, a fabric, in particular a fabric web, within the meaning of the present invention can be a fabric comprising cotton, nylon, polyester, acryl, and/or wool. In some embodiments, the fabric can be a light, a medium, and/or a dark colored fabric.

Within the meaning of the present invention, the fabric web can be a woven fabric web. In particular, the fabric web can be a woven denim fabric web. More in particular, the fabric web can be an indigocolored fabric web. Additionally, or alternatively, the fabric web can be colored according to the padbatch method.

Bentonite clay within the meaning of the present invention can be any clay material that primarily comprises, e.g., a smectite clay mineral, such as montmorillonite, hectorite, or nontronite. The properties of the respective bentonite clay is typically dictated by the respective smectite clay mineral. Without being bound by theory, smectites are generally comprised of stacks of negatively charged layers, wherein each layer is comprised of two tetrahedral sheets attached to one octahedral sheet. Typically, but not always, the tetrahedra is formed by silicon and oxygen atoms and the octahedra is formed by aluminum and oxygen atoms together with hydroxyl radicals, which are balanced and/or compensated by alkaline earth metal cations (e.g. Ca2+ and/or Mg2+) and/or alkali metal cations (eg. Na+ and/or K+). The relative amounts of the two types (alkaline earth metal and alkali metal) of cations typically determine the swelling characteristic of the respective bentonite clay material when placed in water. Bentonites, in which the alkaline earth metal cation Ca2+ is predominant (or is in a relative majority), are often referred to as “calcium bentonites”, whereas bentonites, in which the alkali metal cation Na+ is predominant (or is in a relative majority) are often referred to as “sodium bentonites”. Bentonite clay particles typically have an irregular shape, and/or a craggy appearance. In one embodiment, the dispersion comprising bentonite clay has a swelling capacity within the range of 1 to 70 ml/g, preferably within the range of 2 to 35 ml/g, more preferably within the range of 5 to 30 ml/g, and most preferably within the range of 7 to 20 ml/g.

In a further embodiment, the dispersion comprising bentonite clay is a hydrated bentonite clay. In yet another embodiment, the hydrated bentonite clay has a density in the range of 0.1 to 10 g/1, preferably in the range of 0.5 to 8 g/1, more preferably in the range of 1 to 4 g/1, even more preferably in the range of 1,5 to 2,5 g/1, and most preferably around 2 g/1.

In one embodiment, the hydrated bentonite clay has a moisture content in the range of 1 to 80 wt.-%, preferably in the range of 5 to 50 wt.-%, more preferably in the range of 10 to 20 wt.-%, and most preferably in the range of 11 to 13 wt.-%.

In yet another embodiment, the bentonite clay consists essentially of bentonite clay particles having a particle size of no more than 300 nm, preferably no more than 200 nm, and most preferably no more than 150 nm. According to this embodiment, the bentonite clay particles are typically of a size so that the particles essentially all pass through a No. 325 sieve.

In one embodiment, the hydrated bentonite clay has a viscosity within the range of 1 to too mPa-s at a bentonite clay concentration of 6 wt.-% in water, in particular within the range of 5 to 50 mPa-s, determined at 23 ± 5 °C, preferably at 23 ± 2.5 °C, more preferably at 23 ± 1.5 °C, and most preferably at 23 ± 0.5 °C.

In a further embodiment, the bentonite clay is an aluminum silicate clay comprising sodium oxide, calcium oxide, and/or potassium oxide. In yet another embodiment, the sodium oxide content of the bentonite clay is within the range of 0.1 to 10%, the calcium oxide content of the bentonite clay is within the range of 0.1 to 10%, and/or the potassium oxide content of the bentonite clay is within the range of 0.1 to 10%.

Yet another embodiment relates to the dispersion of the first aspect of the invention, wherein the dispersion is suitable for washing a fabric web being colored according to the pad-batch method.

In all aspects and embodiments of the present invention, which can be combined with any of the other aspects and/or embodiments, the pad-batch method is a cold pad-batch method, or a warm pad-batch method, preferably a cold pad-batch method.

A further embodiment, which can be combined with each embodiment and/or aspect of this invention, pertains to a dispersion according to the first aspect of the invention, wherein the dispersion is suitable for washing a fabric web being colored. According to this embodiment, the fabric web being colored can be colored with any kind of dyes. In a preferred embodiment, the fabric web being colored is colored with reactive dyes. In another embodiment, the fabric web being colored is colored with at least one bifunctional reactive dye. In yet another embodiment, the fabric web being colored is colored with at least one indigo dye.

In one embodiment, the dispersion is suitable for washing a fabric web being continuously guided through the dispersion. The dispersion can be a dispersion according to any of the previously described embodiments of the first aspect of the invention.

A second aspect of the present invention relates to the use of bentonite clay for washing a fabric web. In one embodiment, the fabric web has been colored according to the pad-batch method. Additionally, or alternatively, the second aspect of the present invention pertains to the use of bentonite clay for washing a fabric web being colored with reactive dyes. Said reactive dyes can be indigo dyes.

In one embodiment of the second aspect, the use of bentonite clay for washing a fabric web pertains to the use of a dispersion according to the first aspect of the invention for washing a fabric web. Another embodiment relates to the use of a dispersion according to the first aspect of the invention for washing a fabric web, wherein the fabric web has been colored according to the pad-batch method. Additionally, or alternatively, the fabric web has been colored with reactive dyes.

A third aspect of the present invention relates to a method for washing a fabric web, comprising the step of:

- washing the fabric in at least one bentonite washing step in particular with a dispersion according to the first aspect of the invention; and optionally

- coloring the fabric web according to the pad-batch method before washing the fabric web.

The third aspect of the present invention additionally relates to a method for coloring and washing a fabric web, comprising the steps of:

- coloring the fabric web according to the pad-batch method; and

- washing the fabric web in at least one bentonite washing step with a dispersion according to the first aspect of the invention.

In one embodiment of the third aspect of the present invention, the method further comprises the step of:

- washing the fabric web in at least one pre washing step with a pre washing liquid, and/or

- washing the fabric web in at least one post washing step with a post washing liquid, in particular wherein the post washing liquid comprises an organic acid and/or an inorganic acid, such as Ruco-acid ABS 200, and/or is free of bentonite clay and/or consists of water.

In a preferred embodiment, the method according to the third aspect of the present invention comprises at least one pre washing step with a pre washing liquid, wherein the at least one pre washing step is prior the at least one bentonite washing step. In case the method relates to a method for coloring and washing a fabric web according to the third aspect of the present invention, the method preferably comprises the steps of:

- coloring the fabric web according to the pad-batch method;

- washing the fabric web in at least one pre washing step with a pre washing liquid, in particular wherein the pre washing liquid is free of bentonite clay and/or consists of water, and

- washing the fabric web in at least one bentonite washing step with a dispersion according to the first aspect of the invention.

A further embodiment relates to the method according to the third aspect of the present invention, wherein said method comprises at least one post washing step with a post washing liquid, wherein the at least one post washing step is after the at least one bentonite washing step.

Yet another embodiment relates to the method according to the third aspect of the present invention, wherein said method comprises at least one pre washing step with a pre washing liquid, wherein the at least one pre washing step is prior the at least one bentonite washing step, and comprises at least one post washing step with a post washing liquid, wherein the at least one post washing step is after the at least one bentonite washing step.

A further embodiment relates to a method for coloring and washing a fabric web according to the third aspect of the present invention, the method comprising the steps of:

- coloring the fabric web according to the pad-batch method;

- washing the fabric web in at least one pre washing step with a pre washing liquid, in particular wherein the pre washing liquid is free of bentonite clay and/or consists of water;

- washing the fabric web in at least one bentonite washing step with a dispersion according to the first aspect of the invention, and

- washing the fabric web in at least one post washing step with a post washing liquid, in particular wherein the post washing liquid comprises an organic acid and/or an inorganic acid, such as Ruco-acid ABS 200, and/or is free of bentonite clay and/or consists of water.

In one embodiment, the pre washing liquid is free of bentonite clay and/or consists of water.

Additionally, or alternatively, the post washing liquid comprises an organic acid and/or an inorganic acid, and/ or is free of bentonite clay and/ or consists of water.

Within the meaning of the present invention, the organic acid and/or the inorganic acid can be Ruco- acid ABS 200. Ruco-acid ABS 200 is known to contain both an organic acid and an inorganic acid, and is a buffer solution.

A washing step within the meaning of the present invention can be repeated any number of times. Accordingly, in one embodiment the bentonite washing step of the method according to the third aspect of the present invention can be repeated any number of times. Additionally, or alternatively, the pre washing step can be repeated any number of times. Additionally, or alternatively, the post washing step can be repeated any number of times.

In yet another embodiment, the method according to the third aspect of the present invention comprises:

(i) Between 1 and 5 bentonite washing steps, preferably 1 bentonite washing step, and

(ii) Between 1 and 20 pre washing steps and/or post washing steps, preferably between 2 and 15, more preferably between 4 and 10, and most preferably 7 pre and/or post washing steps, wherein the at least one bentonite washing step is the first, the second, the third, the fourth, the fifth, the sixth, the seventh, the eighth, the ninth, the tenth, the eleventh, the twelfth, or the thirteenth step of the method; preferably wherein the at least one bentonite washing step is the second, the third, the fourth, the fifth, the sixth, or the seventh step of the method; even more preferably wherein the at least one bentonite washing step is the second, the third, or the fourth step of the method; and most preferably wherein the at least one bentonite washing step is the third step of the method.

In one embodiment, the method according to the third aspect of the present invention comprises:

(i) Two pre washing steps;

(ii) One bentonite washing step, and

(iii) Five post washing steps.

In an additional embodiment, the method according to the third aspect of the present invention comprises:

(i) Two pre washing steps with a pre washing liquid, wherein the pre washing liquid is free of bentonite clay and/or consists of water;

(ii) One bentonite washing step;

(iii) Four post washing steps with a first post washing liquid, and

(iv) One post washing step with a second post washing liquid.

In one embodiment, the four post washing steps with a first post washing liquid is with a first post washing liquid that is free of bentonite clay and/or consists of water, and the post washing step with a second post washing liquid is with a post washing liquid comprising an organic acid and/or an inorganic acid, such as Ruco-acid ABS 200. In one embodiment, the post washing step with the second post washing liquid is with a post washing liquid that is free of bentonite clay. Additionally, or alternatively, the post washing step with the second post washing liquid is the last and/or final step of the washing steps of the method for washing a fabric web according to the third aspect of the present invention.

The inventors found that the pH value of the fabric web being washed is important for the strength of the fabric web and/or of the fabric. However, a fabric web being colored according to the pad-batch method usually has an alkali pH, because a pad-batch method within the meaning of the present invention is preferably performed under alkali conditions. Accordingly, a final post washing step with a second post washing liquid, wherein said second post washing liquid comprises an organic acid and/or an inorganic acid, is beneficial for a method for washing a fabric web, in particular for a method for coloring and washing a fabric web, optionally wherein the fabric web is colored according to the padbatch method. For example, the inventors found that using a second post washing liquid with a pH of around 4 is suitable for adjusting the pH of the fabric web and/or the fabric to around 8, which is a pH showing ideal and intended fabric strength.

A further embodiment pertains to the method according to the third aspect of this invention, wherein the at least one bentonite washing step, and optionally the at least one pre washing step and/or the at least one post washing step, is performed at a temperature between 4O°C and too°C, preferably between 5O°C and 9O°C, more preferably between 6o°C and 8o°C, even more preferably between 6s°C and 75°C, and most preferably at around 7O°C.

Importantly, the inventors found that a temperature of around 7O°C is sufficient for washing a fabric web when a dispersion according to the first aspect of the invention is used for washing the fabric web. Contrary, when using a soaping agent that such as Albatex AD, i.e. a soaping agent comprising an anionic surfactant, a non-ionic surfactant and/or an acrylate, as commonly used for washing, a higher temperature of around 9O°C is required for achieving the same washing effect. The requirement of washing at high temperatures of about 9O°C to be effective when washing with a soaping agent such as Albatex AD, compared to washing with a dispersion according to the first aspect of the invention, leads to one of the advantages of the present invention, namely a reduction of energy consumption of the washing process. Accordingly, the dispersion for washing a fabric web according to the first aspect of the invention, uses thereof according to the second aspect of the invention, and methods according to the third aspect of the invention, allows a more sustainable fabric web manufacturing process.

Yet another embodiment relates to the method according to the third aspect of this invention, wherein the fabric web is continuously guided through the dispersion comprising bentonite clay in the at least one bentonite washing step, optionally wherein the fabric web is continuously guided through the pre washing liquid and/or the post washing liquid in the at least one pre washing step and/or the at least one post washing step.

A fourth aspect of this invention relates to a fabric web, in particular a woven fabric web, in particular being colored according to the pad-batch method characterized in that the fabric web was washed, in particular after being colored, with a dispersion comprising bentonite clay, in particular with a dispersion according to the first aspect of this invention, and/or by a method according to the third aspect of this invention.

The fourth aspect of this invention also pertains to a fabric web characterized in that the fabric web was washed with a dispersion according to the first aspect of this invention, and/or by a method according to the third aspect of this invention. In one embodiment, the fabric web according to the fourth aspect of this invention has a color fastness to acid perspiration of 2 to 5 according to EN ISO 105 E04, preferably of 3 to 5, more preferably of 4 to 5, a color fastness to alkaline perspiration of 2 to 5 according to EN ISO 105 E04, preferably of 3 to 5, more preferably of 4 to 5, a color fastness to water of 3 to 5 according to EN ISO 105 E01, preferably of 4 to 5, and/or a color fastness to washing of 3 to 5 according to BS EN ISO 1O5-CO6:2O1O, preferably of 4 to 5, in particular wherein the fabric web (5) has been washed at a temperature between 4O°C and too°C, preferably between 5O°C and 9O°C, more preferably between 6o°C and 8o°C, even more preferably between 6s°C and 75°C, and most preferably at around 7O°C.

In one embodiment, the invention relates to an apparatus for continuously washing a fabric web. The apparatus comprises a reservoir being filled with a dispersion comprising bentonite clay, in particular a dispersion according to the first aspect of the invention. The apparatus additionally comprises at least one drum for guiding the fabric web through the reservoir. The dispersion can be a dispersion according to any of the previously described embodiments of the first aspect of the invention.

According to a fifth aspect of the invention, an apparatus for continuously washing a fabric web is provided. The apparatus comprises a reservoir to be filled with a dispersion. The dispersion to be filled into the reservoir can comprise bentonite clay. In particular, the reservoir can be filled with the dispersion. The apparatus further comprises at least one drum for guiding the fabric web through the reservoir. According to the fifth aspect of the invention, the apparatus comprises a circulation system for counteracting sedimentation of the dispersion in the reservoir.

The dispersion to be filled into the reservoir or being filled in the reservoir can be the dispersion according to the first aspect of the invention or of any embodiments described with respect to the first aspect of the invention. However, the dispersion to be filled or being filled in the reservoir according to this aspect of the invention does not necessarily have to be free of anionic surfactant, non-ionic surfactant and/or acrylate as specified with the first aspect of the invention. In particular, the reservoir according to the fifth aspect of the invention can be filled with a dispersion being specified according to the embodiments of the first aspect of the invention without having to be free of anionic surfactant, non-ionic surfactant and/or acrylate.

Within the meaning of the present invention, the fabric web can be a woven fabric web. In particular, the fabric web can be a woven denim fabric web. More in particular, the fabric web can be an indigocolored fabric web. Additionally, or alternatively, the fabric web can be colored according to the padbatch method.

Within the meaning of the present invention, an apparatus being suitable for continuously washing a fabric web can for this purpose comprise a fabric web inlet for guiding the fabric web into the apparatus and a fabric web outlet for guiding the fabric web out of the apparatus. In order to enable a continuous washing, the fabric web inlet and the fabric web outlet can be designed in that the fabric web can be guided continuously through the apparatus. Continuously in this regard can in particular mean that an endless fabric web can be guided through the apparatus without having to stop the washing operation for the purpose of removing a definite length of fabric web out of the washing apparatus and inserting a second definite length of fabric web into the apparatus.

A reservoir within the meaning of the present invention can be a reservoir being suitable to keep a fluid, in particular a dispersion, inside the reservoir. In particular, the reservoir can be a basin. In particular, the reservoir can margin a volume to be filled with the dispersion. In particular, the reservoir can comprise at least one floor wall and at least one side wall margining a filling volume for the dispersion. In particular, the reservoir can be open in one direction, in particular in the direction opposite to the gravitational direction.

The at least one drum can have a cylindrical shape. The at least one drum can extend along a longitudinal axis, in particular a longitudinal cylindrical axis. The at least one drum can extend in the longitudinal direction for at least 0,5 m, 1,0 m, 1,5 m, 2,0 m, 2,5 m, 3,0 m, 3,5 m or 4,0 m. The at least one drum can have a friction-reduced surface, in particular for avoiding or reducing abrasion of the fabric web.

The at least one drum can be rotatably mounted in particular about the longitudinal axis. The at least one drum can comprise at least one immersion roller. The at least one immersion roller can be mounted within the reservoir. The at least one immersion roller can be mounted in that within the reservoir that at least 20%, 40%, 60%, 80% or 100% of the drum’s extension in the radial direction and/or the horizontal direction is immersed within the dispersion, in particular when the reservoir is filled up to the filling level.

The at least one immersion drum can comprise a plurality, in particular at least two, three, four, five, six or seven, immersion drums. The plurality of immersion drums can be mounted within the reservoir. The plurality of immersion drums can be mounted behind each other in web running direction in that a fabric web being guided through the apparatus passes one immersion drum after the other. The longitudinal axis of the immersion drums can extend parallel to each other. The plurality of immersion drums can be mounted on substantially the same height in the gravitational direction. Substantially in this regard can include a deviation of the mounting position of the longitudinal axis of one immersion drum to the other of maximally 200%, 150%, 100%, 50%, 30%, 20%, 10% or 5% of the diameter of the plurality of immersion drums.

Additionally, the at least one drum can comprise at least one deflection drum being mounted in the web running direction in between two immersion drums in particular in that a fabric web is in the web running direction guided from an upwards mounted immersion drum to a deflection drum where it is deflected to a downwards mounted immersion drum. The at least one deflection drum can comprise a plurality, in particular at least two, three, four, five or six, deflection drums. The plurality of deflection drums can be alternated with the plurality of immersion drums in that the fabric web alternately passes immersion drums and deflection drums. In particular, the plurality of immersion drums and deflection drums can be alternated in that a fabric web passes the immersion drums and deflection drums in a meandering or sinus-like manner. In particular, the deflection drums can be mounted on substantially the same height in the gravitational direction. In particular, the deflection drums can be mounted spaced from the immersion drums in gravitational direction, in particular above the plurality of immersion drums in the gravitational direction. In particular, the longitudinal axis of the deflection drums can be mounted parallel to each other and/or substantially on the same height in gravitational direction.

Additionally, the at least one drum can comprise at least one squeezing drum. The at least one squeezing drum can be mounted adjacent to the at least one deflection drum in that a fabric web running from an immersion drum to the deflection drum is squeezed in between the deflection drum and the squeezing drum. Thereby, a dispersion adhering to the fabric web can partially be squeezed out before the fabric web is conveyed to the next immersion drum. The at least one squeezing drum can comprise a plurality, in particular at least two, three, four, five or six, squeezing drums. In particular, each squeezing drum can be mounted adjacent to one deflection drum for squeezing a fabric web running from an immersion drum to a deflection drum. In particular, the longitudinal axis of the squeezing drums can be mounted parallel to each other and/or substantially on the same height in the gravitational direction.

The plurality of immersion drums, deflection drums and squeezing drums can be mounted in the apparatus in that a plurality of immersion-deflection-squeezing-drum-planes, each of which being defined by the longitudinal axis of one immersion drum, one deflection drum and/or one squeezing drum, are formed. In particular, the immersion-deflection-squeezing-drum-planes extend in the vertical direction and/or parallel to each other.

According to the fifth aspect of the invention, the apparatus comprises a circulation system for counteracting sedimentation of the dispersion in the reservoir. A problem of using bentonite clay for washing a fabric web is that bentonite clay is not soluble to water. Therefore, if bentonite clay would be used in washing apparatuses known in the art, the bentonite clay would sediment to the bottom of the reservoir where it cannot serve as washing agent for washing of color or other substances from the fabric web. The inventive concept of using a circulation system for counteracting sedimentation of the dispersion in the reservoir solves this problem. Such use of a circulation system is a totally new approach for washing of fabric webs going into the opposite direction to recent approaches for reducing water pollution during washing fabric webs. Namely, approaches known in the prior art use the so-called counter flow principle, according to which the reservoir comprises a plurality of washing basins being arranged in the web running direction in ascending stairs in that polluted water flows from the last washing basin to be passed by the fabric web to the first washing basin to be passed by the fabric web so that the fabric web is first washed in a relatively polluted water and in the subsequent washing basins in water becoming cleaner from basin to basin. Before the inventive solution was found, a circulation counteracting sedimentation would have been considered by the skilled person to be contra productive in view of known approaches, such as the counter flow principle, since it would lead to washed off substances being applied again and again to the fabric web. However, thanks to the inventors of the present invention, it has been found that such a circulation system enables the use of bentonite clay within a washing apparatus, the cleaning efficiency of which justifies the costs of implementing such a circulation system and the problems arising upon the circulation of washed off particles which comes with the circulation of the washing dispersion.

The circulation system can be designed in that the dispersion within the reservoir can be circulated. The circulation system can comprise means for keeping the dispersion in motion so as to avoid sedimentation. Such means can be a pump and/or stirring means.

A dispersion within the meaning of the present invention can be understood as a heterogeneous mixture that contains solid particles, such as bentonite clay, in a liquid, such as water. Within the meaning of the present invention, the term “dispersion” can be a particularly heterogeneous mixture that contains bentonite clay particles in a liquid, such as water. Preferably, the bentonite clay particles have a size of no more than 300 nm, more preferably no more than 200 nm, and most preferably no more than 150 nm. Said bentonite clay particles tend to sediment.

Alternatively to a circulation system for counteracting sedimentation of the dispersion and reservoir, the fifth aspect of the invention could also be formulated in that the apparatus comprises a circulation system for causing a washing liquid to flow from an in the gravitation directional lower position to a higher position, in particular in a loop from an in the gravitational direction lower position to a higher position and back to the lower position. Additionally or alternatively, the term “dispersion” can alternatively be called washing liquid comprising one particularly insoluble washing agent, such as bentonite clay.

In the following, the fifth aspect of the invention is further described with reference to the nomenclature, according to which the circulation system is suitable for counteracting sedimentation of the dispersion in the reservoir. However, it shall be clear that all of the following embodiments can also be realized with the alternative nomenclature of the fifth aspect of the invention.

In one embodiment, the circulation system comprises a pump for causing the dispersion to flow from an in the gravitational direction lower position to a higher position of the reservoir. In particular, the pump can cause the dispersion to flow in a loop from the in the gravitational direction lower position to the higher position and back to the lower position of the reservoir. With this embodiment, the invention makes use of the naturally occurring sedimentation of the solid particles in the dispersion in that dispersion at the lower position of the reservoir having a higher content of the solid particles is pumped to a higher position of the reservoir where the solid particles are caused by gravitational force to move back downwards to the lower position of the reservoir so that a continuous flow of the dispersion is provided which particularly keeps the solid particles distributed within the reservoir. Thereby, the circulation system counteracts sedimentation upon causing the solid particles to flow against the gravitational direction. In particular, the circulation system is suitable to cause the solid particles in the dispersion to circulate in a loop, in particular from an in the gravitational direction lower position to a higher position and from the higher position to a lower position. It has surprisingly been found that this circulation of solid particles further increases the washing efficiency of the apparatus, in particular by abrading residues, such as color or other substances, from the fabric web.

In one embodiment, the solid particles are bentonite clay particles, in particular particles of bentonite clay as described in the embodiments of the first aspect of the invention.

Within the meaning of the present invention, sedimentation can be understood as the tendency of solid particles, such as bentonite clay, to settle out of the fluid in which they are entrained and come to rest against the bottom of the reservoir.

In one embodiment, the circulation system comprises a feedback line for receiving the dispersion at the lower position from the reservoir and for leading it through the pump back into the reservoir at the higher position. In particular, the feedback line comprises an outlet section fluidly connecting the lower position of the reservoir with the pump and/or an inlet section fluidly connecting the pump with the higher position of the reservoir. In one embodiment, the lower position refers to the bottom of the reservoir or to a position being maximally 1 mm, 3 mm, 5 mm, 10 mm, 20 mm, 30 mm, 50 mm, 80 mm, too mm above the bottom of the reservoir. Additionally, or alternatively, the higher position is spaced from the lower position against the gravitational direction at least by 0.5, 1.0 or 1.5 times the diameter of the at least one drum, in particular the at least one immersion drum. In particular, the higher position can be on the height of a preset filling level of the reservoir or maximally spaced by 0.7, 0.5, 0.3 or 0.1 times the diameter of the at least one drum of a preset filling level of the reservoir. The feedback line, in particular the outlet section and the inlet section, can be realized by pipes.

According to one embodiment, the reservoir comprises at least two chambers being filled or to be filled with a dispersion, each of which being fluidly connected with the circulation system for counteracting sedimentation in each chamber. The at least two chambers can be fluidly separated from each other in that fluid, in particular the dispersion, does not flow from one chamber directly to the other chamber. Directly can in particular be understood in that fluid cannot flow from one chamber directly to the other but can flow via the circulation system from one chamber to the other. In particular, the circulation system can comprise a plurality of outlet sections and/or inlet sections of the feedback line, each of which fluidly connects the at least two chambers with the circulation system, in particular the pump.

The at least two chambers can be realized by at least one partition wall separating the reservoir into at least two chambers. The at least two chambers can comprise at least three chambers, four chambers, five chambers, six chambers or seven chambers. In particular, the at least two chambers can be realized by at least two, three, four, five or six partition walls. In particular, the reservoir can be a basin. In particular, the at least one partition wall can extend in a longitudinal direction of the at least one drum, in particular parallel to the longitudinal axis of the at least one drum. In particular, the at least one drum can comprise a plurality of immersion drums being distributed within the at least two chambers. In particular, at least one of the plurality of immersion drums can be located in one of the at least two chambers. In particular, the plurality of immersion drums can be separated by the at least two chambers in that at least one, in particular exactly one, immersion drum is located in each of the at least two chambers.

In one embodiment, the plurality of squeezing drums and/or deflection drums can be located in the gravitational direction above the at least two chambers in that at least one, in particular exactly one, squeezing drum and/or deflection drum is located in the gravitational direction above separate chambers. Thereby, it can be achieved that fluid, in particular dispersion is squeezed out of the fabric web in the gravitational direction above each of the at least two chambers in order to reduce fluid, in particular a dispersion, being conveyed via the fabric web from one chamber into the other chamber.

The apparatus can comprise at least one, in particular at least two, shielding walls being arranged in between the plurality of squeezing drums and/or deflection drums. Thereby, it can in particular substantially be avoided that liquid, in particular dispersion, being squeezed out of the fabric web by the deflection drums and/or squeezing drums accidentally flows into chambers being located downstream or upstream of the chamber above which a squeezing drum and/or deflection drum is located in the gravitational direction.

In one embodiment, one shielding wall can be located in web running direction behind each second, in particular behind each, squeezing drum and/or deflection drum. In one embodiment, the at least one shielding wall is located in the gravitational direction above one partition wall. In one embodiment, at least one shielding wall is located in the web running direction above each second, in particular above each, partition wall in the gravitational direction.

The apparatus can comprise one pair of pre-squeezing drums being located in the web running direction upstream of the first immersion drum in web running direction. The pair of pre-squeezing drums can serve to squeeze liquid out of the fabric web before being guided through the reservoir. The pair of pre-squeezing drums can be located in the gravitational direction above a collecting basin for catching the liquid being squeezed off the fabric web by the pair of pre-squeezing drums. The collecting basin can be fluidly connected to a discharge end for discharging the liquid being squeezed off by the pair of pre-squeezing drums from the apparatus. The collecting basin can be fluidly connected with the reservoir. In particular, the collecting basin can be located in the gravitational direction below the filling level of the reservoir. In particular, the filling level of the reservoir can be defined by an overflow edge separating the reservoir from the collecting basin. In particular, the overflow edge separates the reservoir from the collecting basin in that fluid, in particular dispersion, exceeding the filling level, can flow from the reservoir into the collecting basin.

In one embodiment, the apparatus can comprise at least one, in particular at least two, isolation walls. The at least one isolation wall can extend in the gravitational direction from the top of the reservoir towards the reservoir. In particular, the at least one isolation wall can extend in the gravitational direction below the filling level of the apparatus. In particular, the at least one isolation wall can comprise one upstream isolation wall extending below the filling level in particular above the first of the at least one immersion drum in the web running direction and/or one downstream isolation wall extending below the filling level in particular above the last of the at least one immersion drum in the web running direction. In particular, the upstream isolation wall and/or the downstream isolation wall can be part of an isolation chamber. The isolation chamber can isolate the atmosphere within the apparatus from the outside of the apparatus by means of a fluid barrier particularly avoiding that gas can flow into the apparatus. The fluid barrier can be realized by the filling level into which the at least one isolation wall protrudes.

The upstream isolation wall can be located in the web running direction in between the pair of presqueezing drums and the first immersion drum, squeezing drum and/or deflection drum in the web running direction. The downstream isolation wall can be located in the web running direction between the last immersion drum, squeezing drum and/or deflection drum and a pair of post-squeezing drums.

The apparatus can comprise a pair of post-squeezing drums. The pair of post-squeezing drums can be located in the web running direction behind the last of the at least one immersion drums. The pair of post-squeezing drums can be located in the gravitational direction above the last of the at least one immersion drum in that dispersion adhering the fabric web leaving the reservoir from the last immersion drum is squeezed off by the pair of post-squeezing drums and flows back into the reservoir, in particular into the last chamber of the reservoir in the web running direction. The apparatus can comprise at least one post-deflection drum being located in the web running direction before and/or behind the pair of post-squeezing drums. In one embodiment, one post-deflection drum can be located between the last immersion drum and a pair of post-squeezing drums and one post-deflection drum can be located in the web-running direction behind the pair of post-squeezing drums.

In one embodiment, the apparatus comprises a mixing device for providing the dispersion by mixing insoluble particles with a liquid. In particular, the filling volume of the mixing device is at least 5%, 10%, 15%, 20% or 25% larger than the filling volume of the reservoir. Additionally, or alternatively, the mixing device comprises means for heating the dispersion. The mixing device can comprise a mixing tank limiting the filling volume. The mixing tank can have a cylindrical body and a circular-shaped bottom. The mixing device can comprise stands holding the mixing tank. The stands can provide a space between the mixing tank and the bottom. The mixing device can comprise a dispersion discharge for discharging dispersion from the mixing device. The dispersion discharge can be located at the bottom of the mixing tank, in particular within the space between the mixing tank and the floor provided by the stands.

Heating according to the present invention shall preferably relate to heating to a temperature between 4O°C and too°C, more preferably between 5O°C and 9O°C, more preferably between 6o°C and 8o°C, even more preferably between 6s°C and 75°C, and most preferably to around 7O°C. The mixing device can be fluidly connected with the reservoir by a feed line. The feed line can be connected with the bottom of the mixing tank and with the reservoir of the apparatus. On the apparatus side, the feed line can be connected with the reservoir on the gravitational height of the filling level or below the filling level.

In one embodiment, the fabric web being washed according to the present invention can carry away part of the dispersion, in particular the dispersion comprising bentonite clay, while being washed. In this embodiment, it can be advantageous if the filling volume of the mixing device is at least 5%, 10%, 15%, 20% or 25% larger than the filling volume of the reservoir. Additionally, or alternatively, the mixing device can be fluidly connected with the reservoir by a feed line. In one particular embodiment, initially, i.e. in a first step, around 80% is fed to the reservoir by the feed line. During any method and or use of the present invention, the remaining 20% of the dispersion prepared in the mixing device can be fed to the reservoir by the feed line during further steps of the method and or subsequently during the use according to the present invention. This enables the reservoir to be filled with a more or less constant amount of the dispersion, in particular the dispersion comprising bentonite clay, since part of the dispersion is carried away by the fabric web being washed according to the present invention, but this part is then replaced by feeding the remaining 20% of the dispersion prepared in the mixing device to the reservoir by the feed line during further steps of the method and or subsequently during the use according to the present invention.

In a particularly preferred embodiment the filling volume of the mixing device is between 500 and 2000 liters, in particular between 700 and 1500 liters, more particularly between 900 and 1100 liters. In particular the volume of the mixing unit can be about 1000 liters. About can in this regard imply a deviation of ± 1%, 3%, 5%, 10%, 20%, 30%, 40% or 50%. In this embodiment, the volume of the reservoir up to the filling level can be between 200 and 1500 liters, in particular between 400 and 1300 liters, more in particular between 600 and 1000 liters, and most particularly between 700 and 900 liters. In one embodiment, the volume of the reservoir can be about 800 liters. About can in this regard imply a deviation of ± 1%, 3%, 5%, 10%, 20%, 30%, 40% or 50%. Additionally, or alternatively, the mixing device can be fluidly connected with the reservoir by a feed line, and in a preferred embodiment, between 700 and 900 liters, in particular about 800 liters, is initially fed to the reservoir by the feed line. During any method and or use of the present invention, the remaining 100 to 300 liters, in particular the about 200 liters, of the dispersion prepared in the mixing device can be fed to the reservoir by the feed line during further steps of the method and or subsequently during the use according to the present invention. This enables the reservoir to be filled with a more or less constant amount of the dispersion, in particular the dispersion comprising bentonite clay, since part of the dispersion is carried away by the fabric web being washed according to the present invention, but this part is then replaced by feeding the remaining the remaining 100 to 300 liters, in particular the about 200 liters, of the dispersion prepared in the mixing device to the reservoir by the feed line during further steps of the method and or subsequently during the use according to the present invention. The mixing device can further comprise a stirring unit. The stirring unit can be located within the mixing tank, particularly in the middle of the mixing tank. The stirring unit can comprise stirring paddles. The stirring paddles can be connected with a stirring rod. In particular, the stirring unit can comprise at least one pair of stirring paddles being in particular located at the same rotational height. In one embodiment, the stirring unit can comprise two pairs of paddles being spaced from each other in the gravitational direction. In particular, one pair of paddles can extend in vertical and/or horizontal direction. Additionally, or alternatively, one pair of paddles can extend in an angle, in particular of between 5 ⁰ and 30° relative to the vertical direction. In one embodiment, the stirring paddles can be connected with a stirring rod. In one embodiment, the stirring unit, in particular the stirring rod, is driven by a stirring drive. The stirring drive can be a motor, in particular an electromotor. The stirring drive can be located in the gravitational direction above the mixing tank. In particular, the stirring drive can be connected with the top of the mixing tank. In one embodiment the stirring drive can comprise transmission means, in particular a gearbox, connecting the stirring motor with the stirring rod.

The mixing device can comprise a liquid supply for feeding the mixing tank with liquid, in particular with water. The liquid supply can be located at a side wall, particularly a cylindrical wall, of the mixing tank. Additionally, or alternatively, the mixing unit can comprise a particle supply in particular for feeding the mixing tank with particles, in particular insoluble particles, such as bentonite clay. The particle supply can be located within the mixing tank. In particular, the particle supply can be located in the gravitational direction above the liquid supply.

The mixing device can also comprise a control for setting the speed, in particular the rotations per minute, of the stirring device, in particular of the stirring rod. Additionally, or alternatively, the control can be used for setting a specific amount of particles with which the mixing tank shall be supplied. In particular, the amount can be set as particle flow in g/ min. Additionally or alternatively, the control can be used for setting the liquid volume to be fed into the mixing tank. In particular, the liquid volume can be controlled by the volume flow in milliliter/min. Additionally, or alternatively, the control can be used for controlling the means for heating the dispersion. In particular, the control can set a predetermined temperature to which the dispersion shall be heated. The mixing unit can comprise a temperature sensor for measuring the temperature of the dispersion. The temperature sensor can be connected with the control. The control can be programmed in that it controls the power of the heating means depending on the temperature of the dispersion being in particular measured by the temperature sensor.

The mixing device can be structurally separated from the reservoir. The mixing device and the reservoir can be connected with each other by a feed line.

The inventors have found that providing a mixing device is advantageous in that particles, such as bentonite clay, can be mixed with a liquid, such as water, before the resulting dispersion is fed to the reservoir. Thereby, it can be ensured that the particles are properly dispensed in the water when reaching the reservoir. Thereby, a common reservoir with drums for feeding the fabric web through the reservoir can be used for the present invention. This particularly enables to keep costs low for the inventive apparatus. In particular, the use of a separate mixing device allows to use less powerful components, such as the pump, for the circulation system, because the particles are already distributed into the liquid within the mixing device. Thereby, costs and energy of the circulation system can be reduced.

The inventors have also found that providing a mixing device with a larger filling volume compared to the reservoir is of benefit because the surplus of dispersion which can thereby be prepared within the mixing device can be used for continuously feeding the reservoir. Thereby, losses of dispersion within the reservoir being caused by a dispersion leaving the apparatus with the fabric web can be compensated by a continuous flow rate of dispersion from the mixing unit to the reservoir. The inventors have found that the advantage filling volume surplus of 5%, 10%, 15%, 20% or 25% represents a good compromise between costs for a respectively large mixing tank, energy to be used for preparing and/or heating the dispersion in the mixing device and enough surplus of dispersion being prepared in one charge by the mixing device for keeping the filling level in the reservoir filled for a desired charge of fabric web being washed by the apparatus.

Further, the inventors have found that heating the dispersion within the mixing device saves energy compared to only heating the dispersion within the reservoir. In one embodiment, the reservoir can additionally or alternatively comprise means for keeping the temperature of the dispersion within the reservoir. Heating according to the present invention shall preferably relate to heating to a temperature between 4O°C and too°C, more preferably between 5O°C and 9O°C, more preferably between 6o°C and 8o°C, even more preferably between 6s°C and 75°C, and most preferably to around 7O°C.

In one embodiment, the apparatus comprises a dispersion volume control for setting a flow rate of a dispersion feed flow from the mixing unit to the reservoir. The dispersion volume control can be integrated into the control of the mixing device. The dispersion volume control can comprise means for measuring the losses of dispersion volume within the reservoir. The flow rate of dispersion can be set to at least 0.5, 1.0 or 1.5 and/or maximally 2.5, 5, 7.5 or 10 ml of dispersion per kilogram of fabric web being conveyed through the apparatus. For this purpose, the flow rate of the dispersion feed flow can be set in dependence of the conveying speed of fabric web, in particular in m/min through the apparatus. In particular, the dispersion volume control can multiply a preset conveying speed of the fabric web in m/min with the density of the fabric web in kg/m so as to calculate the mass of fabric web being conveyed through the apparatus per minute. On the basis of this mass of fabric web in kilogram being conveyed through the apparatus per minute, the dispersion volume control can set a volume flow in milliliter of dispersion per minute so as to achieve the above-mentioned beneficial volume flow of milliliters of dispersion per kilogram of fabric web being conveyed through the apparatus. In one embodiment, the flow rate of the dispersion feed flow is about 2 ml/kg. About in this regard can imply a deviation of ± 5%, 10%, 20%, 30%, 50% or 70%. These percentage values can relate to volume percent.

The volume of the mixing unit can be between 500 and 2000 liters, in particular between 700 and 1500 liters, more particularly between 900 and 1100 liters. In particular the volume of the mixing unit can be about 1000 liters. About can in this regard imply a deviation of ± 1%, 3%, 5%, 10%, 20%, 30%, 40% or 50%.

The volume of the reservoir up to the filling level can be between 200 and 1500 liters, in particular between 400 and 1300 liters, more in particular between 600 and 1000 liters. In one embodiment, the volume of the reservoir can be about 800 liters. About can in this regard imply a deviation of ± 1%, 3%, 5%, 10%, 20%, 30%, 40% or 50%.

In one embodiment, the invention relates to a washing line with a plurality of apparatuses for continuously washing a fabric web. At least one of the plurality of apparatuses is an apparatus according to the fifth aspect of the invention and/or according to one of the embodiments described with regard to the fifth aspect of the invention. This washing apparatus will subsequently be named circulating apparatus. The circulating apparatus is located in the web running direction behind at least one, in particular at least two, washing apparatuses and/or before at least one, in particular at least two, three or four, washing apparatuses. These washing apparatuses will in the following be called neighboring washing apparatuses. At least one, in particular at least two, three, four, five, six, seven or eight, of the neighboring washing apparatuses can be designed as described with respect to the circulating apparatus. However, the neighboring apparatuses do not necessarily comprise a circulation system and/or a mixing device. In one embodiment, only the circulating apparatus comprises a circulation system and optionally a mixing device, while the neighboring apparatuses are free of a circulation system and/or of a mixing device. However, in alternative embodiments, also one or more of the neighboring apparatuses can comprise a circulation system and/or a mixing device. In particular, one of the neighboring apparatuses, in particular one neighboring apparatus being located in the web running direction behind the circulating apparatus, in particular the second, third, fourth or fifth neighboring apparatus behind the circulating apparatus in the web running direction, comprises a mixing unit and/or a circulation system. In one embodiment the last neighboring apparatus in the web running direction comprises a circulation system and/or a mixing device. Such last neighboring apparatus can in particular be used for washing the fabric web with a liquid comprising water and an organic acid and/or an inorganic acid, such as ruco-acid ABS 200. In one embodiment, only the circulation apparatus, in particular the reservoir of the circulation apparatus, is filled or designed to be filled with a dispersion comprising bentonite clay.

In one embodiment, the washing line comprises at least one drying device being arranged in the web running direction behind the plurality of washing apparatuses. The drying device can be designed for drying a fabric web leaving the plurality of apparatuses at a temperature between too°C and t6o°C, in particular between tto°C and 15O°C, more particularly between 12O°C and 14O°C. In particular, the drying device can heat the fabric web at about 130°. About can in this regard imply deviations of ± 1°C, 2°C, 3°C, 5°C, 7°C or io°C. Temperatures to which it is previously or subsequently referred can refer to degrees in Celsius (C). Additionally, or alternatively, the at least one diying device can be designed for drying a fabric web for 0.5 to 5, in particular 1 to 3.5, more particularly 1.5 to 2.5, minutes. In one embodiment, the drying device can be designed for drying the fabric for about 2 minutes. In particular, about can in this regard imply deviations up to ± 5 seconds, 10 seconds, 20 seconds or 30 seconds.

In one embodiment, the at least one drying device comprises a drying device from the manufacturer Mathis, in particular with product number KTF8803. Such a device is in particular of advantage for laboratory scale washing.

Alternatively, the at least one drying device can comprise a plurality, in particular at least two, four, six, eight or ten, heated drums. The heated drums are in particular alternately arranged in that the fabric web can be guided in a meandering or sinus-like manner through a plurality of heated drums.

In one embodiment the washing line can comprise a downstream winding station for winding the washed fabric web onto a washed fabric web roll at the end of the washing line. Additionally, or alternatively, the washing line can comprise an upstream winding station for unwinding a colored fabric web from a colored fabric web roll at the beginning of the washing line. In one embodiment, the upstream winding station and the downstream winding station represent the start and the end of the washing line.

One embodiment of the invention relates to a fabric web manufacturing line for coloring and washing a fabric web. The fabric web manufacturing line can be a woven fabric web manufacturing line. In particular, the fabric web manufacturing line can be a denim fabric web manufacturing line. The fabric web manufacturing line comprises a pad-batch manufacturing line for in particular semi-continuously coloring the fabric web. Additionally, the fabric web manufacturing line comprises at least one apparatus according to the fifth aspect of the invention and/or any of the embodiments described in the context of the fifth aspect of the invention. Additionally, or alternatively, the fabric web manufacturing line can comprise the previously described washing line for washing the colored fabric web.

The pad-batch manufacturing line can comprise a coloring station for applying color, such as indigo, onto the fabric web. The coloring station can be an impregnation station, in particular a Foulard. Additionally, the pad-batch manufacturing line can comprise a pre-coloring unwinding station being located in the web running direction before the coloring station for unwinding the fabric web from an uncolored fabric web roll. In one embodiment, the pad-batch manufacturing line can comprise a loosening station, in particular a j-box, for providing the fabric web in an unstretched, i.e. loose, condition. In particular, the loosening station is located in web running direction upwards the coring station and/or downwards the pre-coloring unwinding station. In particular, the loosening station serves to bring the fabric web into an unstretched, i.e loose, condition in particular before coloring the fabric web. The inventors have found that using such loosening station is of benefit because the fabric web can in particular be conveyed with low tension or even tensionless through the coloring station which can increase the dye pick up. At the same time, thanks to the loosening station, the uncolored fabric web can be provided as tightly wrapped uncolored fabric web roll to the pre-coloring unwinding station which increases the amount of fabric web which can be colored from one fabric- web roll with the pad-batch method without impairing the coloring efficiency in the coloring station.

Additionally, or alternatively, a post-coloring winding station can be located in the web running direction behind the coloring station for winding the colored fabric onto a colored fabric web roll. According to one embodiment of the invention, the pad-batch manufacturing line is free of heating means for heating the fabric web in between the pre-coloring unwinding station and the post-coloring winding station. Such pad-batch manufacturing line can be called cold pad-batch manufacturing line. In an alternative embodiment, heating means are provided in between the coloring station and the post-coloring winding station so as to heat the fabric web before it is wound onto the roll. Such heating means can be for instance realized by an infrared heating unit.

Additionally, or alternatively, the post-coloring winding station can comprise a film winding station for wrapping a film, in particular a polyethylene film, around the colored fabric web being wound onto the colored fabric web roll. Thereby, it can be ensured that the color being applied to the fabric web at the outer layer of the roll does not diy out too fast. Additionally, in case of the implementation of the heating means in between the coloring station and the post-coloring winding station, the film can decrease the cooling down rate of the fabric web roll. The inventors have found that wrapping the colored fabric web with a film can increase the bonding capacity of the dye.

Additionally, the pad-batch manufacturing line can comprise a resting station where the fabric web roll rests for a predetermined time, in particular between one, two, four, six, eight, eight or twelve and fourteen, sixteen, eighteen, twenty, twenty-two, twenty-four, twenty-six, twenty-eight or thirty hours. In particular, when using the previously described heating unit and/or film winding station, the resting time can be reduced. The resting station can comprise means for rotating the fabric web roll. In particular, the means can be suitable for rotating the fabric roll arounds its rotational axis.

In one embodiment, the resting station can be a thermally regulated room. In particular, in countries where there are great differences between summer and winter temperatures, such a thermally regulated room is beneficial to precisely control the fixation of the color on the fabric web. In particular in the resting station, the color binds on the fabric web.

In one embodiment, the pad-batch manufacturing line comprises means for transporting the colored fabric web roll from the post-coloring winding station to the resting station and/or for transporting the colored fabric web roll from the resting station to the washing apparatus and/ or to the washing line.

In one embodiment, the fabric web manufacturing line comprises a bleaching line. The bleaching line can be located in the manufacturing direction before the pad-batch manufacturing line. The bleaching line can comprise a bleaching station, in particular a bleaching agent application station, such as a Foulard. A pre-bleaching unwinding station can be located in the web running direction before the bleaching station for unwinding the fabric web from a roll. A post-bleaching winding station can be located in the web running direction behind the bleaching station for rolling the fabric well onto a roll. In between the bleaching station and the post-bleaching winding station, a diying device can be located. The drying device can comprise a plurality of heated drums and/ or an infrared heater.

One embodiment of the invention relates to the use of an apparatus according to the fifth aspect of the invention or to any of its embodiments for counteracting sedimentation of bentonite clay in the dispersion. In particular, the reservoir is filled with a dispersion comprising bentonite clay, in particular according to the first aspect of the invention or to any of its embodiments. In particular, the use of the apparatus can relate to a use within the previously described washing line or the previously described fabric manufacturing line. The apparatus can be used for washing a fabric web being colored according to the pad-batch method.

Another embodiment of the invention, which can be combined with the previous embodiment, relates to the use of an apparatus according to the fifth aspect of the invention or to any of its embodiments or to the use of the previously-described washing line or fabric manufacturing line for washing a fabric web being colored according to the pad-batch method. In particular, the use relates in a first step to the use of a pad-batch manufacturing line as previously described and in a second step to the washing of the fabric web with the previously-described apparatus and/or with the previously-described washing line.

According to another embodiment of the invention, an apparatus according to a fifth aspect of the invention or any of its embodiments or the previously-described washing line or the previously- described fabric manufacturing line is used to operate the method or any of its embodiments according to the third aspect of the invention.

Another embodiment of the invention relates to a method for washing a fabric web according to the operation of the apparatus of the fifth aspect of the invention or the operation of any of its embodiments or according to the previously described washing line or according to the previously described fabric web manufacturing line.

Another embodiment of the invention relates to a method for coloring and washing a fabric web according to the operation of the previously described fabric web manufacturing line.

Another embodiment of the invention relates to a fabric web being washed according to the operation of the apparatus according to the fifth aspect of the invention or according to any of its embodiments, according to the operation of the previously described washing line, according to the operation of the previously described fabric manufacturing line or according to any of the previously described methods. The fabric web can in particular be a woven fabric web. Additionally, or alternatively, the fabric web can be a denim fabric web. Additionally, or alternatively, the fabric web can be an indigo- colored fabric web.

Further aspects, properties and features of the invention will become apparent from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings, in which:

Fig. 1 illustrates a washing line with a plurality of apparatuses for continuously washing a fabric web;

Fig. 2 shows an enlarged view of one apparatus for continuously washing the fabric web with a circulation system and a mixing device;

Fig. 3 shows an exemplary embodiment of a pad-batch manufacturing line comprising an upstream winding station, a J-box, an impregnation station and a downstream winding station; and

Fig. 4 shows an exemplary embodiment of a washing line comprising an upstream winding station, three washing apparatuses, a plurality of heating drums and a downstream winding station.

EXAMPLES

Certain aspects and embodiments of the invention will now be illustrated by way of example and with reference to the description, figures and tables set out herein. Such examples of the dispersion, methods, uses and other aspects of the present invention are representative only, and should not be taken to limit the scope of the present invention to only such representative examples. The examples show :

Example 1: Small scale experimental comparison of bentonite clay vs. a commonly used soaping agent

A small-scale experimental comparison of bentonite clay vs. a commonly used soaping agent was performed in a washing line 1 comprising a plurality of apparatuses 3 for continuously washing a fabric web 5. Each of the washing apparatuses 3 comprises a reservoir 7 to be filled with either a pre washing liquid, a dispersion, such as a dispersion comprising bentonite clay, a commonly used soaping agent, or a post washing liquid.

In experiment 1, the washing line 1 comprises four apparatuses 3 for continuously washing a fabric web 5. The first apparatus in the running direction comprises a reservoir 7 to be filled with a pre washing liquid, wherein the pre washing liquid consists essentially of water. The second apparatus in the running direction comprises a reservoir 7 to be filled with either a dispersion, such as a dispersion comprising 2g/l bentonite clay, or a commonly used soaping agent at a concentration of 2g/l. In experiment 1, 2g/l of an Albatex AD solution is used as commonly used soaping/washing agent. In the context of the present invention, Albatex AD shall refer to the sodium salt of a polyaciylic acid, and is known to have anionic character. The third and the fourth apparatus in the running direction comprises a reservoir 7 to be filled with a post washing liquid, wherein the post washing liquid consists essentially of water. Experiment 1 is performed at either 7O°C or 9O°C, as indicated in table 1 and table 2.

Table 1: Experimental setup for testing the efficacy of 2g/l bentonite clay as washing agent in a washing line 1 comprising four apparatuses 3. Each apparatus 3 comprises a reservoir 7 to be filled with either a pre washing liquid, a dispersion, such as a dispersion comprising bentonite clay, or a post washing liquid. For the purpose of table 1, said pre washing liquid, dispersion, or post washing liquid shall be collectively referred to as “filling solution”. Table 2: Experimental setup for testing the efficacy of 2g/l commonly used soaping agent (Albatex AD) as washing agent for comparison in a washing line 1 comprising four apparatuses 3. Each apparatus 3 comprises a reservoir 7 to be filled with either a pre washing liquid, a commonly used soaping agent, or a post washing liquid. For the purpose of table 1, said pre washing liquid, commonly used soaping agent, or post washing liquid shall be collectively referred to as “filling solution”.

After having been washed according to the respective setup as disclosed in table 1 or 2, the fabrics were dried at 13O°C for 2 minute with laboratory type Mathis brand KTF8803 in experiment 1. The results of experiment 1 are shown in tables 3 to 6. The fastness test results are evaluated on a 1-5 scale, with

5 being negligible fastness (i.e. excellent washing agent characteristics)

4 being slightly changed fastness (i.e. good washing agent characteristics)

3 being noticeable changed fastness (i.e. fairly good washing agent characteristics)

2 being considerably changed fastness (i.e. fair washing agent characteristics)

1 being much changed fastness (i.e. poor washing agent characteristics)

Table 3: Fastness test results of the first trial of a small-scale experimental comparison of a dispersion comprising 2g/l bentonite clay vs. a solution comprising 2g/l commonly used soaping agent (Albatex AD) as washing agent. The dispersion comprising 2g/l bentonite clay is referred to as “B”, and the commonly used soaping agent is referred to as “C” in table 3. The test standards used are EN ISO 105 E04 for evaluating the colourfastness to (acid / alkaline) Perspiration, EN ISO 105 E01 for evaluating the colourfastness to water, and EN ISO 105-006:2010 for evaluating the colourfastness to washing. Table 4: Fastness test results of the second trial of a small-scale experimental comparison of a dispersion comprising 2g/l bentonite clay vs. a solution comprising 2g/l commonly used soaping agent (Albatex AD) as washing agent. The dispersion comprising 2g/l bentonite clay is referred to as “B”, and the commonly used soaping agent is referred to as “C” in table 4. The test standards used are EN ISO 105 E04 for evaluating the colourfastness to (acid / alkaline) Perspiration, EN ISO 105 E01 for evaluating the colourfastness to water, and EN ISO 105-006:2010 for evaluating the colourfastness to washing.

Table 5: Crocking and light fastness test results of the first trial of a small-scale experimental comparison of a dispersion comprising 2g/l bentonite clay vs. a solution comprising 2g/l commonly used soaping agent (Albatex AD) as washing agent. The test standards used are EN ISO 105 C06 for evaluating dry and/or wet rocking, and EN ISO 105-B02 for evaluating the colourfastness to light. Table 6: Crocking and light fastness test results of the second trial of a small-scale experimental comparison of a dispersion comprising 2g/l bentonite clay vs. a solution comprising 2g/l commonly used soaping agent (Albatex AD) as washing agent. The test standards used are EN ISO 105 C06 for evaluating dry and/or wet rocking, and EN ISO 105-B02 for evaluating the colourfastness to light.

Experiment 1 demonstrates the improved fastness values when using a dispersion comprising 2g/l bentonite clay compared to a solution comprising 2g/l commonly used soaping agent (Albatex AD) as washing agent for washing a fabric web. Importantly, the inventors also observed said improvement when the fabric web was washed at low temperatures, such as 7O°C. Accordingly, washing a fabric web with a dispersion comprising 2g/l bentonite clay also significantly reduces the energy consumed and the cost for said washing, compared to washing a fabric web with a solution comprising 2g/l commonly used soaping agent (Albatex AD), where a temperature of at least 9O°C is required. Moreover, when washing a fabric web with a dispersion according to the first aspect of this invention, compared to washing the fabric web with commonly used soaping agents, the sustainability of the fabric web manufacturing process is highly enhanced, because the dispersion comprises bentonite clay in water only, i.e. a completely natural agent, and does not comprise any anionic surfactant, non-ionic surfactant, acrylate, and/or other chemical. This results in less water contamination and hence a more sustainable fabric web manufacturing process. Conclusively, comparing the properties of the commonly used soaping agent Albatex AD with a dispersion for washing a fabric web, wherein the dispersion comprises bentonite clay according to the first aspect of this invention, revealed the highly advantageous properties of said dispersion for washing a fabric web according to the present invention.

Example 2: Large scale experimental comparison of bentonite clay vs. a commonly used soaping agent

A large-scale experimental comparison of bentonite clay vs. commonly used soaping agent was performed in a washing line 1 comprising a plurality of apparatuses 3 for continuously washing a fabric web 5. Each of the washing apparatuses 3 comprises a reservoir 7 to be filled with either a pre washing liquid, a dispersion, such as a dispersion comprising bentonite clay, a commonly used soaping agent, or a post washing liquid.

In experiment 2, the washing line 1 comprises eight apparatuses 3 for continuously washing a fabric web 5. The first and the second apparatus in the running direction comprises a reservoir 7 to be filled with a pre washing liquid, wherein the pre washing liquid consists essentially of water. The third apparatus in the running direction comprises a reservoir 7 to be filled with either a dispersion, such as a dispersion comprising 2g/l bentonite clay, or a commonly used soaping agent at a concentration of 2g/l. In experiment 1, 2g/l of an Albatex AD solution is used as commonly used soaping/ washing agent. Albatex AD shall refer to the sodium salt of a polyaciylic acid, and is known to have anionic character. The fourth, fifth, sixth, and seventh apparatus in the running direction comprises a reservoir 7 to be filled with a post washing liquid, wherein the post washing liquid consists essentially of water. The eighth apparatus in the running direction comprises a reservoir 7 to be filled with a post washing liquid, wherein the post washing liquid comprises an organic acid and/or an inorganic acid, such as Ruco-acid ABS 200 in water. Ruco-acid ABS 200 contains both an organic acid and an inorganic acid, and is known to be a buffer solution. The pH of the Ruco-acid ABS 200 in water, as used in the eighth apparatus in the running direction, is around 4. Experiment 2 is performed at either 7O°C or 9O°C, as indicated in tables 7 and table 8.

Table 7: Experimental setup for testing the efficacy of 2g/l bentonite clay as washing agent. Each apparatus 3 comprises a reservoir 7 to be filled with either a pre washing liquid, a dispersion, such as a dispersion comprising bentonite clay, a commonly used soaping agent, or a post washing liquid. For the purpose of table 7, said pre washing liquid, dispersion, commonly used soaping agent, or post washing liquid shall be collectively referred to as “filling solution”. Table 8: Experimental setup for testing the efficacy of 2g/l commonly used soaping agent (Albatex AD) as washing agent in a washing line 1 comprising eight apparatuses 3. Each apparatus 3 comprises a reservoir 7 to be filled with either a pre washing liquid, a dispersion, such as a dispersion comprising bentonite clay, a commonly used soaping agent, or a post washing liquid. For the purpose of table 1, said pre washing liquid, dispersion, commonly used soaping agent, or post washing liquid shall be collectively referred to as “filling solution”.

The results of experiment 2 are shown in tables 9 and 10. The fastness test results are evaluated on a 1- 5 scale, with

- 5 being negligible fastness (i.e. excellent washing agent characteristics)

- 4 being slightly changed fastness (i.e. good washing agent characteristics)

- 3 being noticeable changed fastness (i.e. fairly good washing agent characteristics)

- 2 being considerably changed fastness (i.e. fair washing agent characteristics)

- 1 being much changed fastness (i.e. poor washing agent characteristics)

Table 9: Fastness test results of the first trial of a large-scale experimental comparison of a dispersion comprising 2g/l bentonite clay vs. a solution comprising 2g/l commonly used soaping agent (Albatex AD) as washing agent. The dispersion comprising 2g/l bentonite clay is referred to as “B”, and the commonly used soaping agent is referred to as “C” in table 9. The test standards used are EN ISO 105 E04 for evaluating the colourfastness to (acid / alkaline) Perspiration, EN ISO 105 E01 for evaluating the colourfastness to water, and EN ISO 105-006:2010 for evaluating the colourfastness to washing.

Table 10: Fastness test results of the second trial of a large-scale experimental comparison of a dispersion comprising 2g/l bentonite clay vs. a solution comprising 2g/l commonly used soaping agent (Albatex AD) as washing agent. The dispersion comprising 2g/l bentonite clay is referred to as “B”, and the commonly used soaping agent is referred to as “C” in table 10. The test standards used are EN ISO 105 E04 for evaluating the colourfastness to (acid / alkaline) perspiration, EN ISO 105 E01 for evaluating the colourfastness to water, and EN ISO 105-006:2010 for evaluating the colourfastness to washing.

Experiment 2 demonstrates the improved fastness values when using a dispersion comprising 2g/l bentonite clay compared to a solution comprising 2g/l commonly used soaping agent (Albatex AD) as washing agent for washing a fabric web, even in the large scale setup of experiment 2. Importantly, the inventors also observed said improvement when the fabric web was washed at low temperatures, such as 7O°C. Accordingly, washing a fabric web with a dispersion comprising 2g/l bentonite clay significantly reduces the cost of said washing, compared to washing a fabric web with a solution comprising 2g/l of a commonly used soaping agent, such as Albatex AD. Additionally, washing a fabric web with a dispersion comprising 2g/l bentonite clay also significantly improves the sustainability of the fabric web manufacturing process, compared to washing a fabric web with a commonly used soaping agent in a fabric web manufacturing process.

Example 3: Schematic illustration of a washing apparatus 3 according to the fifth aspect of the invention

Fig. 1 illustrates a washing line 1 with a plurality of apparatuses 3 for continuously washing a fabric web 5. An apparatus 3 for continuously washing a fabric web 5 can also be named washing apparatus 3. The direction in which the fabric web 5 is conveyed through the washing line is illustrated with the arrow W which will in the following be called web running direction. Each of the washing apparatuses 3 comprises a reservoir 7 which can be filled with a liquid, such as a dispersion comprising bentonite clay, a pre washing liquid and/or a post washing liquid, and a plurality of drums 9, 11, 13 for guiding the fabric web 5 through the reservoir 7. The reservoir 7 of the third washing apparatus 3’ in the web running direction W comprises a circulation system 15 for counteracting sedimentation of the dispersion in its reservoir 7. This third washing apparatus 3’ in the web running direction W schematically illustrates a washing apparatus 3 according to the fifth aspect of the invention. Said washing apparatus 3’ will in the following also be called circulating washing apparatus 3’ while washing apparatuses being located in the web running direction W behind or before the circulating apparatus will be called neighboring washing apparatuses 3”. In Figure 1, seven neighboring washing apparatuses 3”are illustrated. Two neighboring washing apparatuses 3” are arranged in web running direction W before the circulating washing apparatus 3’. These two neighboring washing apparatuses 3” can be used for the previously described pre washing steps. Additionally, five neighboring washing apparatuses 3” are arranged in the web running direction W behind the circulating washing apparatus 3’. The last of these neighboring washing apparatuses 3” in web running direction W can be used for the previously described post washing step with a post washing liquid, in particular wherein the post washing liquid comprises an organic acid and/or an inorganic acid, such as Ruco-acid ABS 200, and/or is free of bentonite clay. The four neighboring washing apparatuses 3” in between can be used for post washing steps with pure water. In particular, the washing line 1 shown in figure 1 can be used for conducting washing methods as previously described, in particular as described in the tables 7 and 8.

The circulating washing apparatus 3’ comprises a mixing device 17. The mixing device 17 is connected with the circulating washing apparatus 3’ by a feedline 19. The circulation system 15 comprises a pump 21 for causing the dispersion to flow from an in the gravitational direction G lower position to a higher position of the reservoir 7. Additionally, the circulation system 15 comprises a feedback line 23 for receiving the dispersion at the lower position from the reservoir 7 and leading it through the pump 21 back into the reservoir 7 at the higher position. Example 4: Schematic illustration of a circulating washing apparatus 3’ according to the fifth aspect of the invention

The circulating washing apparatus 3’ will now be described in more detail on the basis of its enlarged view in Fig. 2. In Fig. 2, the pump 21, the feedback line 23, the mixing device 17 and the feed line 19 are shifted towards the circulating washing apparatus 3’ for the purpose of illustration. It shall be clear that the inventive washing apparatus 3’ shall not be limited to a specific relative position of the mixing unit 17 and the circulation system 15 relative to the circulating washing apparatus 3’.

The following description of the immersion drums, the reservoir and the collecting basin shall be considered to represent an embodiment which can be realized for any washing apparatus including the neighboring washing apparatuses 3”, as can be seen in Fig. 1.

The at least one drum comprises a plurality of immersion drums 9. In particular, seven immersion drums 9 are provided. The dashed line 25 schematically illustrates the filling level 25 of the reservoir 7. The filling level 25 is the height to which the reservoir 7 is intended to be filled with a liquid, in particular dispersion, in particular the dispersion with bentonite clay, in particular a dispersion according to the first aspect of the invention. As can be seen in Fig. 2, the plurality of immersion drums are mounted below the filling level 25 within the reservoir 7. Thereby, the immersion drums 9 ensure that the fabric web 5 immerses into the liquid/ dispersion 27 being filled within the reservoir 25 when the fabric web 5 is guided around the plurality of immersion drums 9. The immersion drums 9 are mounted on the same height in the gravitational direction G. Additionally, the immersion drums 9 extend parallel to each other. In particular, the longitudinal axes 29 of the immersion drums 9 extend parallel to each other. In particular, the longitudinal axis 29 of the immersion drums 9 extend parallel to the web cross direction C. The web cross direction C is the direction defining the width of the fabric web, in other words the direction extending orthogonal to the web running direction. In the embodiment of a woven fabric web, the web cross direction C is the direction in which the weft yarns extend. The reservoir 7 comprises seven chambers 31 being filled or to be filled with the dispersion/fluid. Each of the chambers 31 is separated from at least one adjacent chamber by a partition wall 33. The partition walls 33 particularly serve to avoid that dispersion/fluid flows directly from one chamber to another. Each of the plurality of immersion drums 9 is located in a separate chamber 31.

In addition to the plurality of immersion drums 9, the at least one drum comprises a plurality of deflection drums 11. In particular, eleven deflection drums are provided. Each of the deflection drums 11 are located in the web running direction W in between two immersion drums 9 so that the fabric web 5 is guided from an upstream mounted immersion drum 9 to a deflection drum 11 where it is deflected to a downstream immersion drum 9. In particular, the immersion drums 9 and the deflection drums 11 are alternated in that the fabric web 5 passes the washing apparatus 3 in a sinus-like or meandering manner. In particular, each of the deflection drums 11 is mounted in the gravitational direction G above one, in particular its downstream, immersion drum 9. In particular, the deflection drums n are mounted in the gravitational direction G at the same height. In particular, the longitudinal axis 35 of the deflection drums 11 extend parallel to each other and/or on the same height in the gravitational direction G.

In addition to the plurality of immersion drums 9 and deflection drums 11, the at least one drum comprises a plurality of squeezing drums 13. Each of the plurality of squeezing drums 13 is located next to a deflection drum 11 in that a fabric web 5 being guided along a squeezing drum 13 and a deflection drum 11 is squeezed out in between these two drums in that liquid/dispersion adhering to the fabric web 5 is squeezed out between these two drums. In particular, each of the squeezing drums 13 is located in the gravitational direction G between the deflection drum 11 and the in particular upstream immersion drum 9 delivering the fabric web to the squeezing drum 13. In particular, the longitudinal axis 37 of the squeezing drums 13 extend at the same height in the gravitational direction G and/or parallel to each other. In particular, at least two, in Fig. 2 six, of the plurality of immersion drums 9 are followed in the web running direction W by a pair of one squeezing drum 13 and one deflection drum 11 being in particular aligned with the immersion drum 9 in that the longitudinal axes 29, 35 and 37 extend in one plane in particular extending in the vertical direction.

In Fig. 2, shielding walls 39 are mounted in between every two pairs of deflection drums 11 and squeezing drums 13. The shielding walls serve to hinder liquid/dispersion being squeezed out by the pairs of deflection drums and squeezing drums to flow into chambers being located in the web running direction or behind the chamber from which it was absorbed by the fabric web 5.

The circulation washing apparatus 3’ further comprises one upstream isolation wall 41 and one downstream isolation wall 43. The downstream isolation wall 41 extends in the gravitational direction D below the filling level 25. The downstream isolation wall is located above the first immersion drum 9 in the web running direction W. The upstream isolation wall 43 also extends below the filling level 25 in the gravitational direction G and is located in the gravitational direction G above the last immersion wall 9 in the web running direction W. The isolation walls 41, 43 are connected to an isolation chamber 45. The isolation chamber 45 isolates the atmosphere within the washing apparatus 3 from the environment. The isolation is realized by a fluid barrier being realized by the liquid/dispersion being filled up to the filling level 25. As can be seen in Fig. 2, the upstream isolation wall 41 can extend from below the filling level 25 against the gravitation direction G up through a position below the deflection drums 11 and/or squeezing drums 13. From this position, the upstream isolation wall 41 can extend inclined away from the deflection drums and/or squeezing drums 13. The upstream isolation wall 41 can subsequently again extend straight against the gravitational direction G and subsequently merge in the top of the isolation chamber 45. The downstream isolation wall 43 can extend from the top of the isolation chamber 45 in the gravitational direction G until a position shortly above the filling level 25. Shortly above can in this regard include a space from the filling level 35 in the gravitational direction G of at least 5%, 10%, 20%, 30% or 50% of the diameter of the last immersion drum 9 in the web running direction W. In particular, the downstream isolation wall 43 can extend above the last immersion drum 9 in the web running direction W. From the position shortly above the filling level 25, the downstream isolation wall 43 can extend inclined away from the second last immersion drum 9. Below the filling level 25, the downstream isolation wall 43 can again extend straight into the gravitational direction G in particular for about 5%, 10%, 20% or 30% of the diameter of the last immersion drum 9 in the web running direction W. About can in this regard include a deviation of up to 1%, 3%, 5%, 10%, 20%, 30% or 50% of the previously defined extension.

The washing apparatus can also comprise a collecting basin 47. The collecting basin 47 can be located in the gravitational direction G below the filling line 25 as illustrated in Fig. 2. In particular, the collecting basin 47 can serve to collect liquid/dispersion flowing over the filling level 25 of the reservoir 7. The collecting basin 47 and the reservoir 7 can be separated from each other by an overflow edge 49. The overflow edge 49 can define the filling level 25. In case the liquid/dispersion exceeds the filling level 25, a respective additional liquid/dispersion can flow from the reservoir 7 over the overflow edge 49 into the collecting basin 47. The collecting basin can comprise a discharge line 51 through which liquid/dispersion being collected in the collecting basin can leave the washing apparatus 3. The washing apparatus 3 can further comprise a pair of pre-squeezing drums 53. The pair of pre-squeezing drums 53 can serve to squeeze out liquid and/or dispersion of the fabric web 5 before the fabric web 5 immerses into the reservoir 7. In particular, the pair of pre-squeezing drums 53 can be located in the gravitational direction towards the above web collecting basin so that the collecting basin collects liquid/dispersion being squeezed out of the fabric web 5 by the pair of pre-squeezing drums.

Additionally, or alternatively, the washing apparatus 3 can comprise a pair of post-squeezing drums 55. The pair of post-squeezing drums 55 can serve to squeeze out liquid/dispersion from the fabric web 5 leaving the washing apparatus 3. Thereby, the amount of liquid/dispersion being conveyed from one washing apparatus 7 to another can be reduced. Additionally, or alternatively, the washing apparatus can comprise at least one, in particular two post-deflection drums 57. As shown in Fig. 2, one postdeflection drum 57 can be located in the web running direction W before and/or behind the pair of post-squeezing drums 55. In the shown embodiment, one post-deflection drum 57 is located in the web running direction W between the last immersion drum in the web running direction and the pair of post-squeezing drums 55 and one post-deflection drum 57 is located in the web-running direction W behind the pair of post-squeezing drums 55.

The circulation system 15 illustrated in Fig. 2 comprises a pump 21 and a feedback line 23. The feedback line 23 comprises an outlet section 59 for leading the liquid/dispersion from the reservoir 7 to the pump 21 and one inlet section 61 for leading the liquid/dispersion from the pump 21 back into the reservoir 7. As shown in Fig. 2, the outlet section 23 can be connected substantially with the bottom 63 of the reservoir. Substantially can in this regard mean that the middle point of the outlet section 59 at its position at the reservoir 7 can be spaced from the bottom of the reservoir 7 against the gravitational direction G by maximally 100%, 80%, 60%, 50%, 30%, 20%, 10% or 5% of the diameter of the at least one immersion drum 9. Additionally, or alternatively, the inlet section can be connected with the reservoir 7 in the gravitational direction G above, at or below the filling level 25. In Fig. 2, the inlet section 61 is connected with the reservoir 7 above the filling level. The inventors have found that the inlet section 61 shall not be connected too far below the filling level 25 so as to properly avoid sedimentation of the particles in the dispersion. It has been found to be preferred that the inlet section 21 is connected with the reservoir 7 at a height in the gravitational direction of maximally 5%, 10%, 15%, 20%, 30% or 50% of the diameter of the at least one immersion drum 9 below or above the filling level 25.

The circulating washing apparatus 3‘ can also comprise a mixing device 17. The mixing device 17 can be fluidly connected with the reservoir 7 by means of a feedline. The mixing device 17 can comprise a mixing tank 65. The mixing tank 65 can have a cylindrical body and a semicircular shaped bottom. The feedline can be fluidly connected with the bottom of the mixing tank 65. The bottom of the mixing tank 65 can comprise a dispersion discharge 67 for draining dispersion not being required for the washing process or for refeeding insoluble particles from the bottom of the mixing unit to the particle supply 60 described below. The connection of the feedline 19 with the reservoir 7 is only schematically illustrated in Fig. 2. It has been found advantageous to connect the feedline 19 substantially at the height of the filling level with the reservoir 7. Substantially can in this regard include a deviation of ± 5%, 10%, 15%, 20%, 30%, 50% or 70% of the diameter of one of the plurality of immersion drums 9. The mixing device 17 can include a particle supply 69 and a liquid, in particular water, supply 71. It has been found advantageous to locate the particle supply 69 in the gravitational direction G above the liquid supply 71 so as to benefit from the naturally occurring sedimentation of the insoluble particles, such as bentonite clay, within the mixing device 17.

Additionally, the mixing device 17 can comprise a stirring unit 73 for dispensing the particles with the liquid. The stirring unit 73 can comprise a stirring rod 75 and stirring paddles 77. The stirring rod 75 can extend in the gravitational direction G. The stirring paddles 77 can comprise stirring paddles extending straight in the gravitational direction G and/or stirring paddles 77 being inclined relative to the gravitational direction G towards the wall of the mixing tank 65. In the embodiment shown in Fig. 2, one pair of stirring paddles extending straight in the rotational direction and one pair of stirring paddles being inclined towards the wall of the mixing tank 75 are used.

Additionally, the mixing device can comprise a stirring drive 79. The stirring drive 79 can be connected in that it drives the stirring unit 73. The stirring drive 79 can comprise a stirring motor 81. The stirring motor 81 can be directly connected with the stirring unit 73, in particular with the stirring rod 75. However, it has been found advantageous to equip the stirring drive 79 with transitioning means 83, such as a gearbox. As can be seen in Fig.2, the transition means 83 can be located in between the stirring drive 79 and the stirring unit 73, in particular the stirring rod 75. As can be seen in Fig. 2, the stirring drive 69 can be connected with the top of the mixing tank 65.

Additionally, the mixing device 17 can comprise a control 85, in particular a dispersion volume control 85. As previously described, the control 85 can be designed for setting the speed of the stirring unit 73, the feed weight of particles and/or liquid from the particle supply 69 and the liquid supply 71, the heat to be introduced into the liquid/dispersion by the heating means and/or the flow rate of the dispersion /liquid feed flow from the mixing unit 17 to the reservoir 7.

Example 5: Schematic illustration of a washing line 1 according to the present invention

Fig. 3 illustrates a schematic embodiment of a pad-batch manufacturing line 101. The pad-batch manufacturing line 101 comprises in web running direction W a pre-coloring unwinding station 87 and at the end a post-coloring winding station 89. The pre-coloring unwinding 87 serves to unwind the fabric web 5 from an uncolored fabric web roll 91. Subsequently, the fabric web 5 is conveyed through a j-box 99 for bringing the fabric web 5 into an unstretched, i.e. loose, condition. Subsequently, the fabric web 5 is conveyed through a coloring station 97 in form of an impregnation station 97 for applying color to the fabric web. In the illustrated embodiment, the impregnation station 97 is a foulard with which indigo can be applied to the fabric web 5. After leaving the impregnation station 97, the post-coloring winding station 89 winds the colored fabric web 5 into a colored fabric web roll 93. The pad-batch manufacturing line 101 can comprise a not shown film winding station for wrapping a polyethylene film around the colored fabric web roll 93. After the fabric web 5 has been winded into the colored fabric web roll 93, the colored fabric web roll 93 can be stored for several hours in a not shown resting station of the pad-batch manufacturing line 101 in which the color binds on the fabric web 5. The embodiment of the fabric web manufacturing line can in particular be realized by the previously described pad-batch manufacturing line 101 shown in Fig. 3 in combination with the washing line 1 shown in Fig. 1 or with the subsequently described washing line shown in Fig. 4.

Fig. 4 illustrates a schematic embodiment of a washing line 1. In Fig. 4, the eight washing apparatuses 3’, 3” of figure 1 have been reduced to three washing apparatuses 3’, 3”. Therein, the first and the third washing apparatuses 3” in the web running direction W shall represent neighboring washing apparatuses 3” in particular not comprising a circulation system 15 and/or a mixing device 17. The second washing apparatus 3’ in the web running direction W shall represent a circulating washing apparatus 3’ according to the fifth aspect of the invention or any embodiments thereof. The washing line 1 comprises in web running direction W an upstream winding station 105 and at the end a downstream winding station 107. The upstream winding station 105 serves to unwind the fabric web 5 from a colored fabric web roll 109. Preferably, the fabric web 5 of the colored fabric web roll 109 has previously been colored according to the pad-batch method, in particular as described with respect to Fig. 3. The downstream winding station 107 serves to wind the fabric web 5 after its washing by the washing apparatuses 3’, 3” on a washed fabric web roll 111.

The washing line further comprises a drying device 95 for drying the fabric web 5 after leaving the three washing apparatuses 3’, 3”. The drying device comprises one arrangement of a plurality, in particular ten, heated drums being arranged in that the fabric web 5 leaving the washing apparatuses 3’, 3” is conveyed over the heated drums in a meandering or sinus-like manner.

The features disclosed in the above description, the Figures and the claims may be significant for the realization of the invention in its different embodiments individually and in any combination. Reference signs

1 washing line

3 washing apparatus

3’ circulating washing apparatus

3” neighboring washing apparatus

5 fabric web

7 reservoir

9 immersion drum it deflection drum

13 squeezing drum

15 circulation system

17 mixing device

19 feed line

21 pump

23 feedback line

25 filing level

27 liquid/ dispersion

29 longitudinal axis of immersion drum

31 chamber

33 partition walls

35 longitudinal axis of deflection drum

37 longitudinal axis of squeezing drum

39 shielding wall

41 upstream isolation wall

43 downstream isolation wall

45 isolation chamber

47 collecting basin

49 overflow edge

51 discharge line

53 pair of pre squeezing drums

55 pair of post squeezing drums

57 post deflection drum

59 outlet section

61 inlet section

63 bottom of the reservoir

65 mixing tank

67 dispersion discharge

69 particle supply

71 liquid supply

73 stirring unit

75 stirring rod 77 stirring paddles

79 stirring drive

81 stirring motor

83 transmission means/gear box

85 control/ dispersion volume control

87 pre-coloring unwinding station

89 post-coloring unwinding station

91 uncolored fabric web roll

93 colored fabric web roll

95 arrangement of heated drums/drying device

97 coloring station/impregnation station/foulard

99 j-box

101 pad-batch manufacturing line

103 impregnation station/foulard

105 upstream winding station

107 downstream winding station

109 colored fabric web roll

111 washed fabric web roll

W web running direction

C web cross direction

G Gravitational direction