Method for dyeing hook-and-loop fastener strap

Abstract

To provide a method for dyeing a hook-and-loop fastener strap in which a uniform dyeing of the hook-and-loop fastener strap is achieved in a time-saving and reliable manner, and to provide a dyeing system for implementing the method.SOLUTION: The invention relates to a method for dyeing a hook-and-loop fastener strap 12, wherein the hook-and-loop fastener strap 12 continuously passes through a basic or neutral dyeing solution 38 in a dyeing device 36. The dyeing solution 38 deposits itself to the hook-and-loop fastener strap 12. The dyeing solution 38 has a dye 40 that binds to the hook-and-loop fastener strap 12 only when the dyeing solution 38 is in an acidic state. After passing through the dyeing device 36, the hook-and-loop fastener strap 12 with the deposited dyeing solution 38 is guided through a damper 52, causing the dyeing solution 38 to become acidic. The dye 40 adheres to the hook-and-loop fastener strap 12 to dye the hook-and-loop fastener strap 12. The invention also concerns a dyeing system 10 for implementing the method.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] 2. Background of the Invention The present invention relates to a method for coloring hook-and-loop tapes having protruding hooks, mushrooms and / or loops.Furthermore, the present invention relates to a coloring installation for carrying out this method.

[0002] A method for coloring textile articles is known from DE 19610120 A1. DE 10334675 A1 relates to a method for coloring or printing adhesive tape fasteners. A method for fixing colors onto a surface using selected pressure and temperature ranges is disclosed in WO 2008 / 111038 A1.

[0003] EP 0 043 984 A1 relates to a coloring method for coloring or printing fiber mixtures consisting of cellulose and polyester fibers using an acid donor.

[0004] It is known from the prior art to dye hook-and-loop tapes roll by roll in a dye bath. The known method has the disadvantage that it is associated with a relatively high time-consuming effort, in particular in terms of changing the hook-and-loop tapes in the dye bath and possibly in terms of post-processing, in order to achieve a uniform application of color on the hook-and-loop tapes.

[0005] Instead of the roll-by-roll dyeing described above, attempts have been made to dye the hook-and-loop tape continuously. However, the problem in this case is that the hook-and-loop tape has protruding delicate hooks, mushrooms and / or loops, which should have the same color shade as the base material to which they are bonded. In order to achieve uniform dyeing of these delicate structures and the thicker materials to which they are bonded, attempts have been made to use thickeners, but uniform dyeing has not been achieved.

[0006] Problem to be solved by the invention It is an object of the present invention to provide a method for coloring hook-and-loop tapes, which saves time and ensures uniform coloring of the hook-and-loop tapes. It is a further object of the present invention to provide a coloring installation for carrying out the method.

[0007] Description of the Invention According to the invention, this problem is solved by a method according to claim 1. Furthermore, this problem is solved by a coloring installation according to claim 15.

[0008] The method according to the invention comprises the following steps carried out in succession: a) continuously guiding the hook-and-loop tape through a coloring device to apply a coloring solution having a pH value of at least 7 onto the hook-and-loop tape, the coloring solution having a dye, the dye being in particular configured as an acid dye that binds to the hook-and-loop tape at pH values ​​below 7; b) continuously guiding the hook-and-loop tape coated with the coloring solution through a steamer, and lowering the pH value of the coloring solution in the steamer to less than 7 to enhance the adhesion of the dye to the hook-and-loop tape; has.

[0009] The dye of the coloring solution does not immediately bind to the hook-and-loop tape when the dye comes into contact with the hook-and-loop tape. In practice, the dye is first deposited on the hook-and-loop tape, and the dye is uniformly distributed on the surface of the hook-and-loop tape, for example, by diffusion. In this case, the time during which the dye can be distributed on the surface of the hook-and-loop tape can be flexibly adjusted by allowing the hook-and-loop tape to remain in the coloring device for a desired time. This can ensure the uniform distribution of the dye on the surface of the hook-and-loop tape.

[0010] In the steamer, the adhesion of the dye to the hook-and-loop tape is enhanced without disturbing the uniform distribution of the dye on the hook-and-loop tape, thereby ensuring uniform coloring of the hook-and-loop tape. The enhancement of the adhesion of the dye to the hook-and-loop tape is particularly achieved by lowering the pH value in the steamer to less than 7. The enhancement of the adhesion of the dye to the hook-and-loop tape is particularly achieved by the dye binding to the hook-and-loop tape at a pH value of less than 7.

[0011] In the case where the coloring solution has a plurality of dyes, it is possible to prevent the dyes of the coloring solution in the coloring device from strongly adhering (particularly binding) to the hook-and-loop tape at different speeds, which would cause the concentration of the dye on the hook-and-loop tape to deviate from the desired concentration of the dye, thereby resulting in an undesirable overall color of the hook-and-loop tape. Furthermore, the relatively low water consumption within the method makes the coloring of the hook-and-loop tape environmentally friendly and sustainable.

[0012] The hook-and-loop tape is in particular one of the two tapes of a hook-and-loop fastener, which in addition to the hook-and-loop tape has a further hook-and-loop tape that is configured to complement the hook-and-loop tape, whereby a surface bond between the hook-and-loop tape and the further hook-and-loop tape is achieved.

[0013] As dyes, in particular Bemacid Gelb®, Bemacid Rot® and / or Bemacid Marine® are used. Preferred as dyes, in particular as acid dyes, are Amidoschwarz 10 B, in particular with the molecular formula disodium 4-amino-5-hydroxy-3-[(4-nitrophenyl)diazenyl]-6-(phenyldiazenyl)-2,7-naphthalene disulfonate), Acid Yellow 36, in particular with the molecular formula sodium 3-[(4-anilinophenyl)diazenyl]benzenesulfonate), Acid Blue 25, in particular with the molecular formula 1-amino-4-anilino-9,10-dioxoanthracene-2-sulfonic acid (Na salt), and / or Acid Blue 26, in particular with the molecular formula sodium 3-{[{(1Z,4E)-4-[(2-chlorophenyl){4-[ethyl(3-sulfonatobenzyl)amino]-2-methylphenyl}methylene]-3-methyl-2,5-cyclohexadien-1-ylidene}(ethyl)ammonio]methyl}benzenesulfonate. Green 22 is used.

[0014] Examples of acid dyes are: [ka] [ka] It is.

[0015] During the method steps a) and b) are in particular carried out without interruption, ie without any method steps being carried out in between.

[0016] In a preferred variant of the method, the colouring solution comprises an acid donor configured to release acid at a critical value of the control parameters of the steamer in order to lower the pH value of the colouring solution in the steamer.

[0017] By acid donor is understood in particular a chemical compound capable of forming a free acid in aqueous solution.

[0018] Carboxylic acid esters are particularly such compounds. The acid-catalyzed hydrolysis of carboxylic acid esters releases the corresponding carboxylic acid, which can result in a decrease in pH. The acid-catalyzed hydrolysis of esters is particularly temperature-dependent, with the reaction rate increasing with increasing temperature.

[0019] Meropan EF® is a carboxylic acid ester-based acid donor that can reduce the pH value of solutions, especially colored solutions, especially at high temperatures.

[0020] Carboxylic acid esters are organic compounds which are produced in particular by the reaction between carboxylic acids and alcohols, known as esterification, in which, in particular, water is separated as a by-product. R1COOH+R2OH→R1COOR2+H2O

[0021] Esterification is in particular an equilibrium reaction. The reverse reaction of esterification is in particular ester cleavage, also known as ester hydrolysis, in which an ester is cleaved into the corresponding carboxylic acid and alcohol.

[0022] In particular, the hydrolysis of esters leads to a change in pH value, the nature of which depends on whether the hydrolysis takes place in an acidic or basic medium.

[0023] In acid-catalyzed hydrolysis for ester cleavage, esters are treated with water in the presence of an acid such as sulfuric acid. The equilibrium of this reaction is on the side of carboxylic acids and alcohols, especially when water is used in excess. Since carboxylic acids are weak acids and partially dissociate in aqueous solutions, acid-catalyzed hydrolysis can result in the formation of free carboxylic acids, which can cause the pH value to decrease.

[0024] The general reaction scheme is in particular as follows: R1COOR2+H2O→R1COOH+R2OH

[0025] The Arrhenius equation, among other things, describes the relationship between rate constant and temperature:

number

[0026] The acid-catalyzed hydrolysis of esters shows a temperature dependence as well: the reaction rate increases with temperature, in particular due to the promotion of protonation of the carbonyl group of the ester and the subsequent attack of water on the positive carbon.

[0027] As acid donors, the following substances are preferably used: sodium chloroacetate, sodium dichloroacetate, the Na salt of 3-chloropropionic acid, monochloroacetamide, butyrolactone, lauryl sulfate, hexadecyl sulfate, octadecyl sulfate, 2-ethylhexyl sulfate, butyl sulfate, butyl glycol sulfate, butyl diglycol sulfate, C1-C4 alkyl esters of phosphoric acid and / or phosphorous acid, trimethyl phosphate, triethyl phosphate, tris(hydroxyethyl)phosphate, dimethyl phosphate, diethyl phosphatase, In one embodiment, one of the following is used: phosphite, dipropyl phosphite, diisopropyl phosphite, dibutyl phosphite, methanephosphonic acid dimethyl ester, ethanephosphonic acid diethyl ester, phosphonopropionic acid trimethyl ester, cyanoethanephosphonic acid dimethyl ester, cyanomethanephosphonic acid dimethyl ester, hydroxyethanephosphonic acid dimethyl ester and / or hydroxymethanephosphonic acid dimethyl ester, 2-chloroethanephosphonic acid dimethyl ester, 2-chloroethanephosphonic acid diethyl ester, and / or phosphonosuccinic acid tetramethyl ester.

[0028] As acid donor, in particular Meropan RLS® is used.

[0029] In a further development of the aforementioned variant of the method, the control parameter is the temperature of the coloring solution in the steamer, the critical value of the control parameter being in particular in the range from 70° C. to 105° C. The temperature as a control parameter can be adjusted relatively easily.

[0030] In the steamer, the temperature is increased, in particular above 90° C., and the pH value of the coloring solution is reduced, preferably to a value below 6. The aforementioned acid dyes having sulfonic acid residues as hydrophilic substituents are present completely dissociated, especially in this pH range. In this case, the amino groups of the polyamide fibers of the hook-and-loop fastener tape are also present as ammonium cations. The dye anions form substantially salt-like bonds with the functional groups of the fibers, especially in the actual coloring process.

[0031] In an advantageous variant of the method, the colouring solution comprises a first masking substance which, in the colouring device, at a starting value of the control parameter, has a greater affinity for the dye than the affinity of the face material of the hook-and-loop fastening tape for the dye, and in the steamer, at a critical value of the control parameter, the affinity of the first masking substance for the dye is less than the affinity of the face material of the hook-and-loop fastening tape for the dye.

[0032] Within the scope of the present invention, the affinity of one substance for another is understood in particular as the tendency of the substances to bond to each other. The first masking substance deposits on the dye molecules in the coloring device, thereby preventing the dye from adhering to the face material of the hook-and-loop fastening tape. The first masking substance thereby further prevents the dye from bonding to the hook-and-loop fastening tape in the coloring device. In the steamer, the first masking substance releases the dye, thereby allowing the dye to bond to the hook-and-loop fastening tape.

[0033] The hook-and-loop fastener tape is made of a hook-and-loop fastener tape face material having the above-mentioned affinity or binding properties. The face material preferably comprises fibers. As the first masking material, in particular Sarabid IPD® is used.

[0034] A preferred variant of the method is in which the colouring solution comprises a second masking material which, in the colouring device, at a starting value of the control parameter, has an affinity for the face material of the hook-and-loop tape that is greater than the affinity of the dye for the face material of the hook-and-loop tape, and in the steamer, at a critical value of the control parameter, the affinity of the second masking material for the face material of the hook-and-loop tape is less than the affinity of the dye for the face material of the hook-and-loop tape.

[0035] The second masking material deposits on the face material of the hook-and-loop tape in the coloring device faster than the dye deposits on the face material of the hook-and-loop tape. The second masking material thereby further prevents the dye from bonding to the hook-and-loop tape in the coloring device. In the steamer, the second masking material is exchanged for the dye, thereby allowing the dye to bond to the hook-and-loop tape. The hook-and-loop tape is in particular made of a face material. As the second masking material, in particular Sarabid IPF® is used.

[0036] A variant of the method is advantageous in which the hook-and-loop tape is washed in a first washing device, in particular before step a), at a temperature between 40° C. and 70° C. Thereby, dirt residues are removed from the hook-and-loop tape. In particular, the finish is washed off from the hook-and-loop tape.

[0037] In a further development of the aforementioned variant of the method, after the hook-and-loop fastening tape has been washed in a first washing device, the hook-and-loop fastening tape is washed in a second washing device at a temperature between 70°C and 100°C, in particular before step a). This reduces the tension in the hook-and-loop fastening tape, in particular in the textile surface structure of the hook-and-loop fastening tape. Generally, a change in the dimensions of the hook-and-loop fastening tape occurs at the same time, which changes the shape, appearance and / or function of the hook-and-loop fastening tape. The hook-and-loop fastening tape is particularly pliable and flexible.

[0038] In one configuration of the aforementioned further development, after the hook-and-loop fastening tape has been washed in the second washing device, the hook-and-loop fastening tape is washed, in particular before step a), in a third washing device at a temperature between 20° C. and 40° C. The hook-and-loop fastening tape is subjected to quenching, whereby the pliable and flexible state of the hook-and-loop fastening tape is preserved for the subsequent process steps.

[0039] A variant of the process is advantageous in which the control parameter is the temperature of the coloring solution, the critical value of which in the steamer is in particular in the range from 70° C. to 105° C. Preferably, the critical value of the control parameter in the process ranges from 70° C. to 105° C. Temperature is a process parameter that can be controlled relatively easily.

[0040] In a further variant of this method, the hook-and-loop fastener tape comprises, in particular is formed from, a polyamide, when using polyamide, the inventive pH-controlled binding of the dyes being particularly effective.

[0041] In particular, the hook-and-loop fastener tape comprises polyamide fibers, the structural formula of which preferably comprises at least a portion of the following form: [ka] has.

[0042] In a preferred variant of the method, after guiding the hook-and-loop tape through the colouring device according to step a) and before guiding it through the steamer according to step b), the hook-and-loop tape is guided successively between two padding rollers in order to scrape off excess colouring solution.

[0043] A sufficiently large gap is formed between the padding rollers so that the hook-and-loop tape can be guided through the gap while scraping off the dye residues without damaging or destroying the structure of the hook-and-loop tape, in particular the loops, mushrooms and / or hooks, thereby further improving the uniform distribution of the dye on the hook-and-loop tape.

[0044] In a further variant of the method, the colouring solution comprises an alkali, in particular soda, so that the pH value of the colouring solution in the colouring device is at least 7.

[0045] In a preferred variant of the method, the colouring solution comprises an antifoaming agent, which makes it possible to prevent the formation of bubbles during the colouring of the hook-and-loop tape, which would have a detrimental effect on the homogeneous distribution of the dye when it is applied in the colouring device and / or when it is bonded to the hook-and-loop tape in a steamer. Kollasol CDS® is used in particular as an antifoaming agent.

[0046] A variant of the method is advantageous in which the hook-and-loop tape passes through a surge tank when it leaves the steamer. The surge tank is in particular a water container filled with water. The water container is preferably at the outlet of the steamer and the hook-and-loop tape is guided through the surge tank when it leaves the steamer. The transparency of the water in the surge tank is an indication of whether the dye is sufficiently well bonded to the hook-and-loop tape.

[0047] In an advantageous variant of the method, the hook-and-loop fastener tape is passed through a vacuum suction, which achieves a fast and uniform dehydration and cleaning of the hook-and-loop fastener tape, the vacuum suction being carried out in particular both on the upper and lower sides of the hook-and-loop fastener tape.

[0048] A variant of the method is preferred in which the hook-and-loop tape is dried by infrared radiation, which achieves fast and uniform drying of the hook-and-loop tape.

[0049] A variant of the method is advantageous in which the thickness of the layer of dye on the hook-and-loop tape after passing through the method does not exceed a preset maximum thickness and / or does not fall below a preset minimum thickness over a preset length of the hook-and-loop tape, whereby a particularly homogeneous distribution of the dye on the hook-and-loop tape is achieved.

[0050] The coloring equipment for carrying out the above-mentioned method has the following characteristics: I. A coloring device having a coloring solution with a pH value of at least 7, the coloring solution having a dye, the dye being in particular configured as an acid dye that binds to the hook-and-loop fastener tape at pH values ​​below 7; II. A steamer configured to reduce the pH value of the coloring solution to less than 7 to enhance adhesion of the dye to the hook-and-loop fastener tape; III. A hook-and-loop tape being guided through a coloring device and a steamer has.

[0051] This device makes it possible to achieve uniform coloring of the hook-and-loop fastener tape.

[0052] Optionally, the scope of the method according to the invention also includes a step of slightly thickening the colouring solution, in particular with Tubivis Star®.

[0053] Further advantages of the invention will become apparent from the specification and the drawings. Likewise, the features mentioned above and those described in more detail can be used according to the invention, individually by themselves or in any combination. The illustrated and described embodiments should not be understood as a definitive list, but rather have an exemplary character for representing the invention. [Brief description of the drawings]

[0054] [Figure 1] FIG. 2 shows a schematic longitudinal section of a first part of a coloring installation. [Diagram 2] FIG. 3 shows a schematic longitudinal section of a second part of the coloring installation.

[0055] Detailed description of the invention and drawings 1 shows diagrammatically a longitudinal section through a first part of a coloring station 10 for hook-and-loop tapes 12, in which the hook-and-loop tapes 12 pass through a method for coloring the hook-and-loop tapes 12. The hook-and-loop tapes 12 are guided continuously through the coloring station 10 during the method.

[0056] In the coloring facility 10, the hook-and-loop tape 12 is transferred from a storage roll 14 to an article store 16. The description of the hook-and-loop tape 12 in connection with the method for coloring the hook-and-loop tape 12 relates in particular to a portion of the hook-and-loop tape 12 which is on the storage roll 14 at the start of the method and which is unwound from the storage roll 14 during the method and passes through the process steps described below. The rollers 18 of the article store 16 are displaceable relative to one another, in particular vertically, so that the article store 16 can accommodate portions of the hook-and-loop tape 12 of different lengths depending on the position of the rollers 18. The article store 16 thus serves as a store and a buffer for the hook-and-loop tape 12. After leaving the article store 16, the hook-and-loop tape 12 is guided through a web edge control device 20 which is configured to appropriately adjust the orientation of the hook-and-loop tape 12 when passing through the subsequent stations of the coloring facility 10.

[0057] From the web edge control device 20, the hook-and-loop tape 12 passes through a first washing device 22 of a washing facility 24. The first washing device 22 is filled with a washing solution (shown by a curved line) which in particular comprises water, preferably only water. In the first washing device 22, the hook-and-loop tape 12 is washed at a temperature in the range of 40° C. to 70° C., whereby dirty spots on the hook-and-loop tape 12 are removed. In particular, in the first washing device 22, the finish is washed off from the hook-and-loop tape 12. After passing through the first washing device 22, the hook-and-loop tape 12 is guided through a vacuum suction device 26 which sucks the hook-and-loop tape 12 on both sides for the purpose of additional cleaning.

[0058] Subsequently, the hook-and-loop tape 12 passes through a second washing device 28 of the washing facility 24. The second washing device 28 is filled with a washing solution (shown by a curved line) which in particular comprises water, preferably only water. In the second washing device 28, the hook-and-loop tape 12 is hydrofixiert at a temperature in the range of 70° C. to 100° C. Thereby, the tension in the hook-and-loop tape 12 is reduced and the hook-and-loop tape 12 becomes more flexible and pliable.

[0059] Subsequently, the hook-and-loop tape 12 passes through a further web edge control device 20 in order to adjust its orientation. The hook-and-loop tape 12 is then guided through a third washing device 30 of the washing facility 24, in which the hook-and-loop tape 12 is quenched at a temperature in the range of 20° C. to 40° C. in order to obtain the soft state of the hook-and-loop tape 12 achieved in the second washing device 28. The third washing device 30 is filled with a washing solution (shown by a curved line) which in particular comprises water, preferably only water.

[0060] Downstream of the washing facility 24, the hook-and-loop tape 12 is guided through a further vacuum suction device 26. In a subsequent step, the hook-and-loop tape 12 is guided through an infrared dryer 32. The infrared dryer 32 serves for uniform drying of the hook-and-loop tape 12.

[0061] Downstream of the infrared dryer 32 in the direction of movement of the hook-and-loop tape 12, the hook-and-loop tape 12 passes through a cooling section 34 in order to cool the hook-and-loop tape 12. This prevents, in particular, an undesirably premature coloring of the hook-and-loop tape 12 (see below), particularly at the time when the hook-and-loop tape 12 first comes into contact with a dye 40, in particular configured as an acid dye, in a coloring device 36. The orientation of the hook-and-loop tape 12 is then adjusted in a further web edge control device 20.

[0062] Downstream of the web edge control device 20, the hook-and-loop tape 12 passes through a coloring device 36, which in the illustrated configuration is configured as a coloring bath. Within the coloring device 36 is a coloring solution 38 having a pH value of at least 7. The coloring solution 38 is composed of at least a dye 40 and an acid donor 42, the dye 40 being configured to bind to the hook-and-loop tape 12 at pH values ​​of less than 7. In particular, the coloring solution 38 has a plurality of dyes 40, each of which serves to color the hook-and-loop tape 12 a respective one color.

[0063] The acid donor 42 is configured to release an acid at a critical value of the control parameter. The control parameter is in particular the temperature of the coloring solution 38. In the coloring device 36, the coloring solution 38 has a starting value of the control parameter below the critical value of the control parameter. The coloring solution 38 in the coloring device 36 therefore does not bind to the hook-and-loop tape 12. This makes it possible to achieve a uniform distribution of the coloring solution 38 on the surface of the hook-and-loop tape 12. In particular, it is possible to prevent different dyes 40 from binding to the hook-and-loop tape 12 at different speeds, which would cause the concentration of the dyes 40 on the hook-and-loop tape 12 to deviate from the desired concentration of the dyes 40, which would result in an undesirable overall color of the hook-and-loop tape 12. Here, the critical value of the control parameter is in particular the temperature value of the coloring solution 38, which is 100°C.

[0064] Furthermore, the coloring solution 38 also contains, inter alia, a first masking substance 44 and a second masking substance 46. The first masking substance 44 binds to the dye 40 faster than the face material 48 of the hook-and-loop tape 12 binds to the dye 40 at the starting value of the control parameter. The second masking substance 46 binds to the face material 48 of the hook-and-loop tape 12 faster than the dye 40 binds to the face material 48 of the hook-and-loop tape 12 at the starting value of the control parameter. The first and second masking substances 44, 46 inhibit the initial binding of the dye 40 to the hook-and-loop tape 12 in order to improve the uniform distribution of the coloring solution 38 on the surface of the hook-and-loop tape 12 in the coloring apparatus 36.

[0065] Downstream of the coloring device 36, the hook-and-loop tape 12 is guided through padding rollers 50. The padding rollers 50 are spaced apart such that the dye 40 can be scraped off the surface of the hook-and-loop tape 12 without damaging the structure of the hook-and-loop tape 12. In this way, excess dye 40 is removed from the hook-and-loop tape 12 and the application of the dye 40 on the hook-and-loop tape 12 is made more uniform.

[0066] From the padding roller 50, the hook-and-loop tape 12 enters a steamer 52, where water vapor is present as saturated steam in the illustrated configuration. In this case, atmospheric oxygen is completely or almost completely removed from the steamer 52. In the steamer, the value of the control parameter is increased to a critical value. In particular, the hook-and-loop tape 12 with the coloring solution 38 applied thereto is heated to at least 100° C. The acid donor 42 releases acid in the steamer 52 when the critical value is reached by the control parameter, in particular when the coloring solution 38 on the hook-and-loop tape 12 is heated to 100° C. In this case, the pH value of the coloring solution 38 falls below 7. The first masking substance 44 is configured to release the dye 40 in the steamer 52 when the control parameter assumes a critical value, in particular when the coloring solution 38 in the steamer 52 is heated to 100° C. The second masking material 46 is configured such that when the control parameters assume critical values, in particular when the coloring solution 38 in the steamer 52 is heated to 100° C., the second masking material 46 in the steamer 52 is replaced by the dye 40 of the face material 48. By lowering the pH value of the coloring solution 38 and changing the binding properties of the masking materials 44, 46 in the steamer 52, the binding of the dye 40 to the hook-and-loop tape 12 is achieved. In this case, the binding of the dye 40 to the hook-and-loop tape 12 occurs with a uniform distribution and composition of the dye 40 on the surface of the hook-and-loop tape 12. Thereby, the hook-and-loop tape 12 is uniformly colored.

[0067] At the outlet 54 of the steamer 52 through which the hook-and-loop tape 12 is guided, there is a surge tank 56, which in the illustrated configuration is configured as a water container filled with water (shown by a curved line). The hook-and-loop tape 12 is guided through the water in the surge tank 56. The water in the surge tank remains clear if the dye does not peel off from the hook-and-loop tape 12 and does not reach the water. The clarity of the water in the surge tank 56 is therefore an indication of whether the dye 40 is binding to the hook-and-loop tape 12 as intended.

[0068] FIG. 2 shows, diagrammatically in longitudinal section, a second part of the coloring station 10 which is connected in the conveying direction of the hook-and-loop fastener tape 12 to the first part of the coloring station 10 shown in FIG.

[0069] Downstream of the surge tank 56 in the conveying direction of the hook-and-loop fastener tape 12 (see FIG. 1), the hook-and-loop fastener tape 12 is guided through a further vacuum suction device 26 .

[0070] Subsequently, the hook-and-loop tape 12 enters a further washing facility 58 with a first washing unit 60, a second washing unit 62 and a third washing unit 64, which in the illustrated configuration are configured in the form of an open container, in order to remove the unbound coloring solution 38 from the hook-and-loop tape 12. To this end, in the washing units 60, 62 and 64 of the further washing facility 58, respectively, there is a washing agent, which is shown in FIG. 2 as a curved line in the washing units 60, 62, 64. The washing agent in particular comprises water, preferably only water. Between the first and second washing units 60, 62, the hook-and-loop tape 12 passes through a further web edge control device 20. Between the second and third washing units 62, 64, the hook-and-loop tape 12 is guided through the further web edge control device 20 in order to adjust the orientation of the hook-and-loop tape 12.

[0071] Downstream of the further washing facility a further vacuum suction device 26 is arranged for washing the coloured hook-and-loop fastening tape 12 .

[0072] Downstream of the further vacuum suction device 26, the hook-and-loop tape 12 passes through an ironing station 66 which has a plurality, in particular four, electric heating cylinders 68 arranged in series, along which the hook-and-loop tape 12 is guided, whereby the hook-and-loop tape 12 is smoothed for the subsequent coating process. Downstream of the ironing station 66 there is a further web edge control device 20 for adjusting the orientation of the hook-and-loop tape 12.

[0073] Downstream of the further web edge control device 20 in the direction of travel of the hook-and-loop tape 12, the hook-and-loop tape 12 is guided through a kiss roller 70. By using the kiss roller 70, the hook-and-loop tape 12 can be covered efficiently.

[0074] Subsequently, the hook-and-loop fastener tape is guided to a dryer 72 where the hook-and-loop fastener tape 12 is dried for further use.

[0075] The hook-and-loop fastener tape 12 is wound onto a further storage roll 74 downstream of the dryer 72 for further use.

[0076] Having seen an overview of all the drawings, the present invention relates to a method for coloring a hook-and-loop tape 12, in which the hook-and-loop tape 12 is continuously passed through a basic or neutral coloring solution 38 in a coloring device 36. The coloring solution 38 is deposited on the hook-and-loop tape 12. The coloring solution 38 has a dye 40 that binds to the hook-and-loop tape 12 only when the coloring solution 38 is in an acidic state. After passing through the coloring device 36, the hook-and-loop tape 12 with the coloring solution 38 deposited thereon is guided through a steamer 52, which achieves that the coloring solution 38 becomes acidic. The dye 40 adheres to the hook-and-loop tape 12 in order to color the hook-and-loop tape 12. Furthermore, the present invention relates to a coloring installation 10 for carrying out this method. [Explanation of symbols]

[0077] 10 Coloring equipment 12 Hook and Loop Tape 14 Storage Roll 16 Goods storage 18 Item storage rollers 20 Web edge control device 22 First cleaning device 24 Cleaning Equipment 26 Vacuum suction device 28 Second Cleaning Device 30 Third cleaning device 32 Infrared dryer 34 Cooling section 36 Coloring device 38 Coloring Solution 40 dye 42 Acid donor 44 First Masking Substance 46 Second Masking Substance 48 Surface Material 50 Padding Roller 52 Steamer 54 Steamer Exit 56 Surge Tank 58 Further cleaning facilities 60 First washing unit of further washing installation 62 Second washing unit of further washing installation 64 Third washing unit of further washing facility 66 Ironing facilities 68 Ironing equipment cylinder 70 Kiss Roller 72 Dryer 74 More Storage Rolls

Claims

1. A method for coloring a hook-and-loop fastening tape (12) having hooks, mushrooms and / or loops, comprising the following steps carried out in succession: a) continuously guiding the hook-and-loop tape (12) through a coloring device (36) to apply a coloring solution (38) having a pH value of at least 7 onto the hook-and-loop tape (12), the coloring solution (38) having a dye (40), the dye (40) being configured in particular as an acid dye that binds to the hook-and-loop tape (12) at a pH value of less than 7; b) continuously guiding the hook-and-loop tape (12) coated with the coloring solution (38) through a steamer (52), in which the pH value is reduced to less than 7 to enhance adhesion of the dye (40) to the hook-and-loop tape (12). A method comprising:

2. 2. The method of claim 1, wherein the coloring solution (38) comprises an acid donor (42) configured to release an acid at a critical value of a control parameter of the steamer (52) to lower the pH value of the coloring solution (38) in the steamer (52).

3. 3. The method according to claim 2, wherein the control parameter is the temperature of the coloring solution (38) in the steamer (52), and the critical value of the control parameter is in particular in the range of 70°C to 105°C.

4. 3. The method of claim 2, wherein the coloring solution (38) comprises a first masking material (44) that has a greater affinity for the dye (40) than the affinity of the face material (48) of the hook-and-loop tape (12) for the dye (40) in the coloring device (36) at the starting value of the control parameter, and wherein the affinity of the first masking material (44) for the dye (40) is less than the affinity of the face material (48) of the hook-and-loop tape (12) for the dye (40) in the steamer (52) at the critical value of the control parameter.

5. 2. The method according to claim 1, wherein the hook-and-loop fastener tape (12) is washed in a first washing device (22) at a temperature between 40°C and 70°C, in particular before step a).

6. 6. The method according to claim 5, wherein after washing the hook-and-loop fastener tape (12) in the first washing device (22), the hook-and-loop fastener tape (12) is washed in a second washing device (28) at a temperature of 70°C to 100°C, in particular before step a).

7. 7. The method according to claim 6, wherein after washing the hook-and-loop fastener tape (12) in the second washing device (28), the hook-and-loop fastener tape is washed in a third washing device (30) at a temperature of 20°C to 40°C, in particular before step a).

8. 2. A method according to claim 1, wherein the control parameter is the temperature of the colouring solution (38), the critical value of which in the steamer (52) is in particular in the range of 70°C to 105°C.

9. 2. The method according to claim 1, wherein the hook-and-loop fastener tape (12) comprises, in particular is made of, polyamide.

10. 2. The method according to claim 1, wherein after guiding the hook-and-loop tape (12) through the coloring device (36) in accordance with step a), and before guiding the hook-and-loop tape (12) through the steamer (52) in accordance with step b), the hook-and-loop tape (12) is guided successively between two padding rollers (50) to scrape off excess coloring solution (38).

11. 2. The method according to claim 1, wherein the coloring solution (38) comprises an alkali, in particular soda, such that the pH value of the coloring solution (38) in the coloring device (36) is at least 7.

12. The method of claim 1, wherein the coloring solution (38) comprises an antifoaming agent.

13. The method of claim 1, wherein the hook-and-loop tape (12) passes through a surge tank (56) upon exiting the steamer (52).

14. The method of claim 1, wherein the hook-and-loop tape (12) is passed through a vacuum suction.

15. 2. The method of claim 1, wherein the thickness of the layer of dye (40) on the hook-and-loop tape (12) after passing through the method does not exceed a predetermined maximum thickness and / or does not fall below a predetermined minimum thickness over a predetermined length of the hook-and-loop tape (12).

16. A coloring installation (10) for carrying out the method according to any one of claims 1 to 15, comprising: I. A coloring device (36) having a coloring solution (38) with a pH value of at least 7, said coloring solution (38) having a dye (40), said dye (40) being configured as an acid dye that binds to said hook-and-loop tape (12) at pH values ​​of less than 7; II. a steamer (52) configured to reduce the pH value of the coloring solution to less than 7 to enhance adhesion of the dye (40) to the hook-and-loop fastener tape (12); III. A hook-and-loop fastener tape (12) guided through the coloring device (36) and the steamer (52). A coloring facility (10) comprising:

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