Method for dyeing magic tape

Abstract

The invention relates to a method for dyeing a fastening tape 12, wherein the fastening tape 12 is continuously passed through an alkaline or neutral dyeing solution 38 in a dyeing device 36. In this case, a dyeing solution 38 is deposited on the fastening tape 12. The dyeing solution (38) contains a dye (40) that binds to the fastening tape (12) only in the acidic state of the dyeing solution (38). After passing through the dyeing device 36, the fastening tape 12 together with the deposited dyeing solution 38 is directed through an evaporator 52, which causes the dyeing solution 38 to become acidic. The dye 40 is adhered to the hook-and-loop fastener 12 to dye the hook-and-loop fastener 12. The invention also relates to a dyeing device 10 for carrying out the method.

Description

Technical Field

[0001] The invention relates to a method for dyeing a hook and loop fastener having protruding hooks, mushrooms and / or loops and to a dyeing device for carrying out the method. Background Art

[0002] DE 196 10 120 C2 discloses a method for dyeing textiles. DE 103 34675 A1 relates to a method for dyeing or printing adhesive tape closures. WO 2008 / 111038 A2 discloses a method for fixing inks to surfaces using a selected pressure range and temperature range.

[0003] EP 0 043 984 A1 relates to a dyeing process for dyeing or printing a fiber mixture of cellulose fibers and polyester fibers using an acid donor.

[0004] Dyeing the hook and loop fastener in a dyeing trough is known in the prior art. The disadvantage of these known methods is the relatively high time consumption, especially due to the replacement of the hook and loop fastener in the dyeing trough and the possible aftertreatment for achieving uniform coloring on the hook and loop fastener.

[0005] As an alternative to the above-mentioned roll-by-roll dyeing, attempts have been made to dye the hook and loop fastener continuously. However, the problem is that the hook and loop fastener has prominent filigran hooks, mushrooms and / or loops that should have the same color tone as the base material to which they are connected. In order to achieve uniform dyeing of these filigrand structures and the more solid material to which they are connected, attempts have been made to use thickeners, but uniform dyeing has not been achieved. Summary of the invention

[0006] The object of the present invention is to provide a method for dyeing a hook and loop fastener, wherein uniform dyeing of the hook and loop fastener is achieved in a time-saving and reliable manner. Another object of the present invention is to provide a dyeing device for implementing the method. DETAILED DESCRIPTION OF THE INVENTION

[0008] According to the invention, this object is achieved by a method according to claim 1. This object is also achieved by a dyeing device according to claim 15.

[0009] The method according to the invention comprises the following steps which are carried out in sequence:

[0010] a) continuously guiding the hook and loop fastener through a dyeing device in order to apply a dyeing solution having a pH value of at least 7 to the hook and loop fastener, wherein the dyeing solution contains a dye, wherein the dye is particularly configured as an acid dye, which is bound to the hook and loop fastener at a pH value of less than 7;

[0011] b) continuously guiding the hook and loop fastener with the applied dye solution through an evaporator, wherein the pH value of the dye solution in the evaporator is lowered to below 7 in order to enhance the adhesion of the dye to the hook and loop fastener.

[0012] When dye contacts with Velcro, the dye of dyeing solution does not directly bind to Velcro. On the contrary, dye is first deposited on Velcro, and wherein dye is evenly distributed on the surface of Velcro, for example, by diffusion. Here, the time period that dye can be distributed on Velcro surface can be flexibly regulated in the following manner: Velcro is retained in dyeing device on desired time period. Can guarantee the uniform distribution of dye on Velcro surface thus.

[0013] The adhesion of the dye on the hook and loop fastener is enhanced in the evaporator without adversely affecting the uniform distribution of the dye on the hook and loop fastener. Thus, the uniform dyeing of the hook and loop fastener is obtained in a reliable manner. In particular, the adhesion of the dye on the hook and loop fastener is enhanced by reducing the pH value in the evaporator to below 7. The adhesion of the dye on the hook and loop fastener is enhanced in particular by the following manner, that is, the dye is bonded to the hook and loop fastener when the pH value is lower than 7.

[0014] In the case where the dyeing solution contains a plurality of dyes, the dyes of the dyeing solution in the dyeing device can be prevented from adhering to the hook and loop fastener (especially being bonded to the hook and loop fastener) at different speeds, so that the dye concentration on the hook and loop fastener deviates from the desired dye concentration, thereby resulting in an undesirable overall color of the hook and loop fastener. In addition, within the scope of the method, the water consumption is relatively small, so that the dyeing of the hook and loop fastener is carried out in an environmentally friendly and sustainable manner.

[0015] The hook and loop fastener refers in particular to one of the two tapes of the hook and loop fastener. The corresponding hook and loop fastener also has another hook and loop fastener that is configured to be complementary to the hook and loop fastener in addition to the hook and loop fastener so as to realize the hook and loop fastening connection of the hook and loop fastener and the other hook and loop fastener.

[0016] Especially use and / or As a dye. As a dye, especially as an acid dye Preferably, Amidoschwarz 10B, especially Amidoschwarz 10B having the general formula of disodium 4-amino-5-hydroxy-3-[(4-nitrophenyl)diazenyl]-6-(phenyldiazenyl)-2,7-naphthalene disulfonate, Acid Yellow 36, especially Acid Yellow 36 having the general formula of sodium 3-[(4-anilinophenyl)diazenyl]benzenesulfonate, Acid Blue 25, especially Acid Blue 25 having the general formula of 1 ... -4-anilino-9,10-dioxoanthracene-2-sulfonic acid (sodium salt)), and / or Acid Green 22, in particular Acid Green 22 of the general formula 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 sodium.

[0017] Examples of acid dyes are

[0018]

[0019] CI Acid Orange 19

[0020]

[0021] CI Acid Blue 117

[0022] During the method, steps a) and b) are carried out in particular without interruption, ie without method steps being carried out in between.

[0023] In a preferred variant of the method, the dyeing solution contains an acid donor which is designed to release acid when a control parameter of the evaporator is at a critical value in order to reduce the pH value of the dyeing solution in the evaporator.

[0024] Acid donors are understood in particular to mean compounds which can form the free acid in aqueous solution.

[0025] Carboxylic acid esters are in particular such compounds. In the acid-catalyzed hydrolysis of carboxylic acid esters, in particular the corresponding carboxylic acid is released, which can lead to a decrease in the pH value. The acid-catalyzed hydrolysis of esters exhibits in particular temperature dependence, ie the reaction rate increases with increasing temperature.

[0026] In particular, It is a carboxylic acid ester acid donor that can reduce the pH value of solutions, especially dyeing solutions, at higher temperatures.

[0027] Carboxylic acid esters are organic compounds which are formed in particular by the reaction of carboxylic acids with alcohols, a reaction known as esterification. In this reaction, in particular water is released as a by-product.

[0028] R1COOH+R2OH→R1COOR2+H2O

[0029] The esterification reaction is, in particular, an equilibrium reaction. The reverse reaction of the esterification reaction is, in particular, the ester cleavage reaction, also known as ester hydrolysis, in which the ester is cleaved into the corresponding carboxylic acid and alcohol.

[0030] During the hydrolysis of esters, in particular the pH changes, and the nature of the change depends on whether the hydrolysis takes place in an acidic or alkaline medium.

[0031] In the process of acid-catalyzed hydrolysis for ester cleavage, the ester is treated with water, especially in the presence of an acid such as sulfuric acid. The equilibrium of the reaction is especially on the side of carboxylic acid and alcohol, especially when an excess of water is used. Acid-catalyzed hydrolysis leads especially to the formation of free carboxylic acids, which can lower the pH value, since carboxylic acids are weak acids and partially dissociate in aqueous solution.

[0032] The general reaction equation is specifically:

[0033] R1COOR2+H20→R1COOH+R2OH

[0034] The Arrhenius equation specifically describes the relationship between the rate constant and temperature:

[0035]

[0036] Specifically:

[0037] (A) is the pre-exponential factor (frequency factor),

[0038] (Ea) is the activation energy,

[0039] (R) is the universal gas constant,

[0040] (T) is the absolute temperature in Kelvin.

[0041] The acid-catalyzed hydrolysis of esters in particular also shows temperature dependence. The reaction rate in particular increases with temperature, since the protonation of the carbonyl group of the ester and the subsequent attack of water on the normalized carbon are promoted.

[0042] Preference is given to using one of the following as the acid donor: sodium chloroacetate, sodium dichloroacetate, 3-chloropropionic acid sodium salt, 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, Esters, tris(hydroxyethyl) phosphate, dimethyl phosphate, diethyl phosphite, dipropyl phosphite, diisopropyl phosphite, dibutyl phosphite, dimethyl methanephosphonate, diethyl ethylphosphonate, trimethyl phosphonopropionate, dimethyl cyanoethanephosphonate, dimethyl cyanomethanephosphonate, dimethyl hydroxyethane and / or hydroxymethanephosphonate, dimethyl 2-chloroethanephosphonate, diethyl 2-chloroethanephosphonate and / or tetramethyl phosphonosuccinate.

[0043] Especially using Meropan As an acid donor.

[0044] In a development of the above-mentioned variant of the method, the control parameter is the temperature of the dyeing solution in the evaporator, wherein the critical value of the control parameter is in particular in the range of 70° C. to 105° C. The temperature can be adjusted relatively easily as a control parameter.

[0045] In the evaporator, the temperature is increased to above 90° C. and the pH of the dyeing solution is preferably reduced to a value of less than 6. The above-mentioned acid dyes with sulfonic acid groups as hydrophilic substituents are completely dissociated in this pH range. In particular, the amine groups of the polyamide fibers of the hook and loop fastener are also present as ammonium cations. In particular, during the actual dyeing process, the dye anions essentially form salt bonds with the functional groups of the fibers.

[0046] In an advantageous variant of the method, the dyeing solution comprises a first masking material, and in the dyeing device, when the control parameter is an initial value, the affinity of the first masking material to the dye is greater than the affinity of the fastening material of the Velcro for the dye, wherein in the evaporator, when the control parameter is a critical value, the affinity of the first masking material to the dye is less than the affinity of the fastening material of the Velcro for the dye.

[0047] In the scope of the present invention, the affinity of a substance to another substance is specifically understood as the tendency of substances to combine with each other. The first masking material is deposited on the molecules of the dye in the dyeing device, and prevents the dye from adhering to the fastening material of the fastener tape thus. Thus, the first masking material also prevents the dye from being attached to the fastener tape in the dyeing device. In the evaporator, the first masking material lets go of the dye, so that the dye can be attached to the fastener tape thus.

[0048] The hook and loop fastener is composed in particular of a hook and loop fastener material having the above-mentioned affinity properties or binding properties. The hook and loop fastener material preferably contains fibers. Especially useful as first masking material.

[0049] A variant of the method is preferred, wherein the dyeing solution contains a second masking material, and in the dyeing device, when the control parameter is an initial value, the affinity of the second masking material to the fastening material of the fastening tape is greater than the affinity of the dye to the fastening material of the fastening tape, and wherein in the evaporator, when the control parameter is a critical value, the affinity of the second masking material to the fastening material of the fastening tape is less than the affinity of the dye to the fastening material of the fastening tape.

[0050] In the dyeing device, the second masking material is deposited on the hook and loop material of the hook and loop fastener faster than the dye. Thus, the second masking material also prevents the dye from binding to the hook and loop fastener in the dyeing device. In the evaporator, the second masking material is replaced by the dye, thereby enabling the dye to bind to the hook and loop fastener. The hook and loop fastener is particularly composed of the hook and loop material. Especially useful as a second masking material.

[0051] A variant of the method is advantageous in which, in particular before step a), the hook and loop fastener is cleaned in a first cleaning device at a temperature of 40° C. to 70° C. This removes dirt residues from the hook and loop fastener. In particular, softeners are washed out of the hook and loop fastener.

[0052] In a further development of the above-mentioned variant of the method, after the hook and loop fastener has been cleaned in the first cleaning device, in particular before step a), the hook and loop fastener is cleaned in a second cleaning device at a temperature of 70° C. to 100° C. This removes textile fabrics from the hook and loop fastener, in particular from the hook and loop fastener. The stress in the fastener is usually reduced. Usually, the dimensions of the fastener change at the same time, thereby changing the shape, appearance and / or function of the fastener. In particular, the fastener becomes soft and elastic.

[0053] In one design of the aforementioned improved solution, after the hook and loop fastener is cleaned in the second cleaning device, in particular before step a), the hook and loop fastener is cleaned in a third cleaning device at a temperature of 20° C. to 40° C. The hook and loop fastener is rapidly cooled, whereby the soft and elastic state of the hook and loop fastener is maintained in subsequent process steps.

[0054] A variant of the method is advantageous in which the control parameter is the temperature of the dyeing solution, wherein the critical value of the control parameter in the evaporator is in particular in the range from 70° C. to 105° C. Preferably, the critical value of the control parameter within the scope of the method is in the range from 70° C. to 105° C. Temperature is a process parameter which is relatively easy to control.

[0055] In another variant of the method, the hook and loop fastener contains polyamide and in particular consists of polyamide. The pH-controlled dye binding according to the invention is particularly effective when polyamide is used.

[0056] In particular, the hook and loop fastener comprises polyamide fibers, the structural formula of which preferably has at least a segment of the following form:

[0057]

[0058] In a preferred variant of the method, after guiding the hook and loop fastener through the dyeing device according to step a) and before guiding the hook and loop fastener through the evaporator according to step b), the hook and loop fastener is continuously guided between two rollers in order to scrape off excess dyeing solution.

[0059] A sufficiently large gap is formed between the rollers so that the hook and loop fastener can pass through the gap when scraping off the residual dye without damaging or destroying the structure, especially the loop, mushroom shape and / or hook of the hook and loop fastener. This further improves the uniform distribution of the dye on the hook and loop fastener.

[0060] In a further variant of the method, the dyeing solution contains an alkali, in particular soda, so that the pH value of the dyeing solution in the dyeing device is at least 7.

[0061] In a preferred variation of the method, the dyeing solution comprises a defoamer. Thus, foam formation can be prevented when the hook and loop fastener is dyed. When dye is applied in a dyeing device and / or when dye is attached to the hook and loop fastener in an evaporator, the formation of this foam may have an adverse effect on the uniform distribution of the dye. Especially used as a defoamer.

[0062] Advantageously, a variant of the method is provided in which the hook and loop fastener passes through a water seal when leaving the evaporator. The water seal is in particular a water container filled with water. The water container is preferably located in the outlet of the evaporator, wherein the hook and loop fastener is guided through the water seal when leaving the evaporator. The transparency of the water in the water seal is an indicator of whether the dye is sufficiently well bonded to the hook and loop fastener.

[0063] In an advantageous variant of the method, the hook and loop fastener is passed through a vacuum suction device. The vacuum suction device results in rapid and uniform dehumidification and cleaning of the hook and loop fastener. The vacuum suction is carried out in particular on both the upper side and the lower side of the hook and loop fastener.

[0064] A variant of the method is preferred in which the hook and loop fastener is dried using infrared radiation. Infrared radiation leads to rapid and uniform drying of the hook and loop fastener.

[0065] Advantageously, a variation of the method is provided, wherein after the method, the dye layer thickness on the hook and loop fastener is not higher than a preset maximum thickness and / or not lower than a preset minimum thickness on the preset length of the hook and loop fastener, causing the dye to be particularly evenly distributed on the hook and loop fastener.

[0066] The dyeing equipment used to implement the above method has the following characteristics:

[0067] I. a dyeing device, comprising a dyeing solution with a pH value of at least 7, wherein the dyeing solution contains a dye, wherein the dye is particularly constituted as an acid dye, and the dye is bound to the hook and loop fastener at a pH value of less than 7;

[0068] II. An evaporator, wherein the evaporator is configured to reduce the pH of the dyeing solution to below 7 in order to enhance the adhesion of the dye on the hook and loop fastener.

[0069] III. Velcro, wherein the Velcro is guided through the dyeing device and the evaporator.

[0070] The device can achieve uniform dyeing of the Velcro.

[0071] The process according to the invention optionally also includes a step in which the dyeing solution is slightly thickened, in particular using

[0072] Further advantages of the invention are apparent from the description and the drawings. Likewise, the features mentioned above and to be described further can be used individually or in multiples in any combination according to the invention. The embodiments shown and described are not to be understood as a final enumeration, but rather have exemplary characteristics for describing the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 A longitudinal section schematically shows a first portion of a dyeing apparatus;

[0074] Figure 2 A second part of the dyeing plant is schematically shown in longitudinal section. DETAILED DESCRIPTION

[0075] Figure 1 The longitudinal section of a first part of a dyeing device 10 for a hook and loop fastener 12 is schematically shown, wherein the hook and loop fastener 12 is subjected in the dyeing device 10 to a method for dyeing the hook and loop fastener 12. The hook and loop fastener 12 is guided continuously through the dyeing device 10 during the method.

[0076] In dyeing equipment 10, hook and loop fastener 12 moves to fabric storage 16 from storage reel 14. About hook and loop fastener 12, the explanation relevant with the method for dyeing hook and loop fastener 12 particularly relates to the partial section of hook and loop fastener 12, this partial section is positioned on storage reel 14 when described method begins and unwinds from storage reel 14 within the scope of described method, so that the processing step described below is carried out. The roller 18 of fabric storage 16 particularly can move relative to each other along vertical direction, and wherein fabric storage 16 can accommodate the partial band of different lengths of hook and loop fastener band 12 according to the position of roller 18. Fabric storage 16 is thus used as storage and buffer of hook and loop fastener 12. After leaving fabric storage 16, guide hook and loop fastener 12 to pass through web edge control device 20, and this web edge control device is constructed to be used for adjusting the orientation of hook and loop fastener 12, so that it is suitable for passing the subsequent station of dyeing equipment 10.

[0077] The hook and loop fastener 12 passes from the web edge control device 20 through the first cleaning device 22 of the cleaning device 24. The first cleaning device 22 is filled with a cleaning solution (indicated by wavy lines), which in particular contains water, preferably only water. In the first cleaning device 22, the hook and loop fastener 12 is cleaned at a temperature in the range of 40° C. to 70° C. This removes dirt spots on the hook and loop fastener 12. In particular, the softener is washed out of the hook and loop fastener 12 in the first cleaning device 22. After passing through the first cleaning device 22, the hook and loop fastener 12 is guided through a vacuum suction device 26, which sucks the hook and loop fastener 12 on both sides for further cleaning.

[0078] Next, the hook and loop fastener 12 passes through a second cleaning device 28 of the cleaning device 24. The second cleaning device 28 is filled with a cleaning solution (indicated by a wavy line), which in particular contains water, preferably only water. In the second cleaning device 28, the hook and loop fastener 12 is wet-fixed at a temperature in the range of 70° C. to 100° C. This eliminates stress in the hook and loop fastener 12, so that the hook and loop fastener 12 is softer and more elastic.

[0079] Next, the hook and loop fastener 12 passes through another fabric edge control device 20 to adjust its orientation. Subsequently, the hook and loop fastener 12 moves through the third cleaning device 30 of the cleaning device 24, wherein the hook and loop fastener 12 is quenched at a temperature in the range of 20° C. to 40° C. in order to maintain the soft state obtained by the hook and loop fastener 12 in the second cleaning device 28. The third cleaning device 30 is filled with a cleaning solution (indicated by a wavy line), which in particular contains water, preferably only water.

[0080] After passing through the cleaning device 24, the hook and loop fastener 12 is guided through a further vacuum extractor 26. In the next step, the hook and loop fastener 12 is guided through an infrared dryer 32. The infrared dryer 32 ensures that the hook and loop fastener 12 is dried evenly.

[0081] When behind the infrared dryer 32 in the direction of movement of the hook and loop fastener 12, the hook and loop fastener 12 passes through a cooling zone 34 in order to cool the hook and loop fastener 12. This prevents undesired premature dyeing of the hook and loop fastener 12, in particular when the hook and loop fastener 12 first comes into contact with a dye 40 (which is in particular configured as an acid dye) in the dyeing device 36 (see below). The orientation of the hook and loop fastener 12 is then adjusted in a further web edge control device 20.

[0082] After passing through the web edge control device 20, the hook and loop fastener 12 passes through a dyeing device 36, which is configured as a dyeing tank. In the dyeing device 36 is a dyeing solution 38 with a pH value of at least 7. The dyeing solution 38 consists of at least a dye 40 and an acid donor 42, wherein the dye 40 is configured to bind to the hook and loop fastener 12 when the pH value is less than 7. In particular, the dyeing solution 38 contains a plurality of dyes 40, wherein each dye 40 is used to dye the hook and loop fastener 12 into a color.

[0083] The acid donor 42 is configured to release the acid when the control parameter is a critical value. The control parameter refers in particular to the temperature of the dyeing solution 12. In the dyeing device 36, the dyeing solution 12 has an initial value of the control parameter, which is lower than the critical value of the control parameter. Therefore, in the dyeing device 36, the dyeing solution 12 will not be combined with the hook and loop fastener 12. This can cause the dyeing solution 38 to be evenly distributed on the surface of the hook and loop fastener 12. In particular, different dyes 40 can be prevented from being combined with the hook and loop fastener 12 at different speeds, so that the concentration of the dye 40 on the hook and loop fastener 12 deviates from the desired concentration of the dye 40, thereby resulting in an undesirable overall color of the hook and loop fastener 12. The critical value of the control parameter is in particular a temperature value of 100°C of the dyeing solution 38.

[0084] In addition, the dyeing solution 38 also contains, in particular, a first masking material 44 and a second masking material 46. When the control parameter is an initial value, the first masking material 44 is bonded to the dye 40 faster than the hook and loop material 48 of the hook and loop fastener 12. When the control parameter is an initial value, the second masking material 46 is bonded to the hook and loop fastener 12 faster than the dye 40. The first and second masking materials 44, 46 prevent the dye 40 from being bonded to the hook and loop fastener 12 at the beginning, so as to improve the uniform distribution of the dyeing solution 38 in the dyeing device 36 on the surface of the hook and loop fastener 12.

[0085] After passing through the dyeing device 36, the hook and loop fastener 12 is guided through rollers 50. A spacing is configured between the rollers 50 so that the dye 40 is scraped off the surface of the hook and loop fastener 12 without damaging the structure of the hook and loop fastener 12. Here, excess dye 40 is removed from the hook and loop fastener 12 and the coating of the dye 40 on the hook and loop fastener 12 is further homogenized.

[0086] The hook and loop fastener 12 comes out of the roller 50 and arrives at the evaporator 52, in which there is water vapor, here as saturated steam. Here, the air oxygen is completely or almost completely removed from the evaporator 52. In the evaporator, the value of the control parameter is increased to a critical value. In particular, the hook and loop fastener 12 with the dyeing solution 38 applied is heated to at least 100° C. When the control parameter reaches the critical value, the acid donor 42 releases the acid in the evaporator 52, especially when the dyeing solution 38 on the hook and loop fastener 12 is heated to 100° C. Here, the pH value of the dyeing solution 38 drops to less than 7. The first masking material 44 is configured so that when the control parameter takes a critical value, in particular when the dyeing solution 38 in the evaporator 52 is heated to 100° C., the first masking material 44 in the evaporator 52 releases the dye 40. The second masking material 46 is configured so that when the control parameter takes a critical value, in particular when the dyeing solution 38 in the evaporator 52 is heated to 100° C., the second masking material 46 in the evaporator 52 is replaced by the dye 40 on the hook and loop material 48. The dye 40 is bonded to the hook and loop tape 12 by lowering the pH value of the dyeing solution 38 and by the changed bonding properties of the masking materials 44 and 46 in the evaporator 52. Here, the dye 40 is bonded to the hook and loop tape 12 by uniform distribution and composition of the dye 40 on the surface of the hook and loop tape 12. The hook and loop tape 12 is thus uniformly dyed.

[0087] There is a water seal 56 at the outlet 54 of the evaporator 52, through which the hook and loop fastener 12 is drawn from the evaporator 52, and the water seal is constructed as a water container filled with water (indicated by wavy lines). The hook and loop fastener 12 is guided through the water in the water seal 56. If no dye is released from the hook and loop fastener 12 and enters the water, the water in the water seal remains transparent. Therefore, the transparency of the water in the water seal 56 is an indicator of whether the dye 40 is attached to the hook and loop fastener 12 as designed.

[0088] Figure 2 A longitudinal section schematically shows a second part of the dyeing device 10, which is connected to the fastener 12 in the conveying direction. Figure 1 After the first part of the dyeing device 10 is shown.

[0089] In the conveying direction of the hook and loop fastener 12, behind the water seal 56 (see Figure 1 ) guide the Velcro 12 through another vacuum extractor 26.

[0090] Next, the hook and loop fastener 12 arrives in another cleaning device 58 having a first cleaning unit 60, a second cleaning unit 62 and a third cleaning unit 64, wherein the first cleaning unit, the second cleaning unit and the third cleaning unit are configured in the form of open containers in order to remove the unbound dyeing solution 38 from the hook and loop fastener 12. For this purpose, a cleaning agent is respectively present in the cleaning units 60, 62 and 64 of the other cleaning device 58, and the cleaning agent is Figure 2 60,62,64. The cleaning agent contains water, preferably only water. Between the first and second cleaning units 60,62, the hook and loop fastener 12 passes through another web edge control device 20. Between the second and third cleaning units 62,64, the hook and loop fastener 12 is guided through another web edge control device 20 in order to adjust the orientation of the hook and loop fastener 12.

[0091] A further vacuum extractor 26 is arranged downstream of the further cleaning device for cleaning the dyed hook and loop fastener 12 .

[0092] After passing through the further vacuum extractor 26, the hook and loop fastener 12 passes through an ironing device 66 having a plurality of, in particular four, electrically heated cylinders 68 arranged in series, along which the hook and loop fastener 12 is guided. This allows the hook and loop fastener 12 to be flattened for the subsequent coating process. Behind the ironing device 66 is another web edge control device 20 for adjusting the orientation of the hook and loop fastener 12.

[0093] Behind the further web edge control device 20 in the running direction of the hook and loop fastener 12, the hook and loop fastener 12 is guided through a padding roller 70. By means of the padding roller 70, the hook and loop fastener 12 can be coated effectively.

[0094] The hook and loop fastener 12 is then directed to a dryer 72 where it is dried for further use.

[0095] After the dryer 72, the hook and loop fastener 12 is wound onto another storage roll 74 for further use.

[0096] In summary, all the accompanying drawings, the present invention generally relates to a method for dyeing a hook and loop fastener 12, wherein the hook and loop fastener 12 is continuously passed through an alkaline or neutral dyeing solution 38 in a dyeing device 36. Here, the dyeing solution 38 is deposited on the hook and loop fastener 12. The dyeing solution 38 contains a dye 40, which is only attached to the hook and loop fastener 12 in the acidic state of the dyeing solution 38. After passing through the dyeing device 36, the hook and loop fastener 12 is guided through an evaporator 52 together with the deposited dyeing solution 38, wherein the dyeing solution 38 is made acidic. The dye 40 adheres to the hook and loop fastener 12 to dye the hook and loop fastener 12. The present invention also relates to a dyeing device 10 for implementing the method.

[0097] Reference numerals list

[0098] 10Dyeing equipment

[0099] 12 Velcro

[0100] 14 Storage Reels

[0101] 16 Fabric Storage

[0102] 18 Rollers for fabric storage

[0103] 20-frame edge control device

[0104] 22First cleaning device

[0105] 24Cleaning equipment

[0106] 26 Vacuum Extractor

[0107] 28 Second cleaning device

[0108] 30 The third cleaning device

[0109] 32 Infrared Dryer

[0110] 34 Cooling Zone

[0111] 36 Dyeing device

[0112] 38 staining solution

[0113] 40 dyes

[0114] 42 acid donor

[0115] 44 First masking material

[0116] 46 Second masking material

[0117] 48 Velcro material

[0118] 50 rollers

[0119] 52 Evaporator

[0120] 54 Evaporator outlet

[0121] 56 Water Seal

[0122] 58 Another cleaning equipment

[0123] 60 A first cleaning unit of another cleaning device

[0124] 62 A second cleaning unit of another cleaning device

[0125] 64 A third cleaning unit of another cleaning device

[0126] 66 Ironing equipment

[0127] 68 Ironing equipment cylinder

[0128] 70 padding roller

[0129] 72 Dryer

[0130] 74 Another storage reel

Claims

1. A method for dyeing a hook and loop fastener (12), the hook and loop fastener having hooks, mushroom shapes and / or loops, wherein the method comprises the following steps, which are performed successively: a) continuously guiding the hook and loop fastener (12) through a dyeing device (36) in order to apply a dyeing solution (38) having a pH value of at least 7 to the hook and loop fastener (12), wherein the dyeing solution (38) contains a dye (40), wherein the dye (40) is in particular an acid dye which binds to the hook and loop fastener (12) at a pH value of less than 7; b) continuously guiding the hook and loop fastener (12) with the applied dye solution (38) through an evaporator (52), wherein the pH value in the evaporator (52) is lowered to below 7 in order to enhance the adhesion of the dye (40) to the hook and loop fastener (12).

2. The method according to claim 1, wherein the dyeing solution (38) comprises an acid donor (42), and the acid donor (42) is configured to release acid when a control parameter of the evaporator (52) is a critical value to reduce the pH value of the dyeing solution (38) in the evaporator (52).

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

4. A method according to claim 2 or 3, wherein the dyeing solution (38) contains a first masking material (44), and in the dyeing device (36), when the control parameter is an initial value, the affinity of the first masking material to the dye (40) is greater than the affinity of the fastening material (48) of the fastening tape (12) to the dye (40), and wherein in the evaporator (52), when the control parameter is a critical value, the affinity of the first masking material (44) to the dye (40) is less than the affinity of the fastening material (48) of the fastening tape (12) to the dye (40).

5. The method according to any of the preceding claims, wherein, in particular before step a), the hook and loop fastener (12) is cleaned in a first cleaning device (22) at a temperature of 40°C to 70°C.

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

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

8. The method according to any of the preceding claims, wherein the control parameter is the temperature of the dyeing solution (38), wherein the critical value of the control parameter in the evaporator (52) is in particular in the range of 70°C to 105°C.

9. The method according to any of the preceding claims, wherein the hook and loop fastener (12) contains polyamide, in particular consists of polyamide.

10. A method according to any one of the preceding claims, wherein after guiding the hook and loop fastener (12) through the dyeing device (36) according to step a) and before guiding the hook and loop fastener (12) through the evaporator (52) according to step b), the hook and loop fastener (12) is continuously guided between two rollers (50) to scrape off excess dyeing solution (38).

11. The method according to any of the preceding claims, wherein the dyeing solution (38) contains an alkali, in particular soda, so that the pH value of the dyeing solution (38) in the dyeing device (36) is at least 7.

12. The method according to any one of the preceding claims, wherein the dyeing solution (38) comprises a defoaming agent.

13. Method according to any of the preceding claims, wherein the hook and loop fastener (12) passes through a water seal (56) when leaving the evaporator (52).

14. Method according to any of the preceding claims, wherein the hook and loop fastener (12) is passed through a vacuum suction device.

15. A method according to any one of the preceding claims, wherein after passing through the method, the thickness of the dye (40) layer on the Velcro (12) is not higher than a preset maximum thickness and / or not lower than a preset minimum thickness over a preset length of the Velcro (12).

16. A dyeing device (10) for implementing the method according to any one of the preceding claims, wherein the dyeing device (10) has: I. a dyeing device (36), comprising a dyeing solution (38) having a pH value of at least 7, wherein the dyeing solution (38) contains a dye (40), wherein the dye (40) is in particular constituted as an acid dye, and the dye is bound to the hook and loop fastener (12) at a pH value of less than 7; II. an evaporator (52), wherein the evaporator (52) is configured to reduce the pH value of the dyeing solution to below 7 so as to enhance the adhesion of the dye (40) to the hook and loop fastener (12); III. The hook and loop fastener (12), wherein the hook and loop fastener (12) is guided through the dyeing device (36) and the evaporator (52).

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