Application method of blue-drying process on vegetable tanned leather

Abstract

The present application discloses an application method of a blue-printing process on vegetable-tanned leather, and relates to the technical field of vegetable-tanned leather dyeing; the application method comprises the following steps: S1, preparation of blue-printing liquid: mixing solution A and solution B in a light-proof environment and stirring evenly to obtain blue-printing liquid; solution A is ammonium ferric citrate, and solution B is potassium ferrocyanide; S2, coating: taking vegetable-tanned leather, in a light-proof environment, evenly applying the blue-printing liquid on the surface of the vegetable-tanned leather, or applying the blue-printing liquid to the surface of the vegetable-tanned leather for rubbing; then standing to dry or blowing dry under cool wind conditions to obtain a base plate; S3, exposure: placing a shielding object on the base plate, exposing it under ultraviolet light, or directly placing the base plate under ultraviolet light for exposure; the present application pioneered the application of the blue-printing process to vegetable-tanned leather, effectively expanding the diversity of materials applied to the blue-printing process, providing a theoretical basis for artistic creation of vegetable-tanned leather, and stimulating the design creativity of artists in this field.

Description

Technical Field

[0001] The present application relates to the technical field of vegetable tanned leather dyeing, and in particular to a method for applying a blue-drying process to vegetable tanned leather. Background Art

[0002] Vegetable tanned leather is a type of leather made by tanning the first layer of cowhide with vegetable tanning agents as the main tanning agent. It is a subdivision of the first layer of cowhide, also known as leather carving leather, tree paste (cake) leather, cassia bark, and belt leather. Vegetable tanned leather has the characteristics of low elongation, good formability, high elasticity, and easy softening after absorbing water. At present, there are few studies on the use of blue-drying technology in the dyeing of vegetable tanned leather on the market. This application aims to study the application of blue-drying technology on vegetable tanned leather to fill the gap in this field. Summary of the invention

[0003] The purpose of this application is to provide a method for applying the blue-drying process to vegetable tanned leather.

[0004] The method comprises the following steps:

[0005] S1. Preparation of blue-drying solution: Mix solution A and solution B in a light-proof environment and stir evenly to obtain the blue-drying solution; the solution A is ammonium ferric citrate, and the solution B is potassium ferrocyanide;

[0006] S2, coating: take vegetable tanned leather, and in a light-proof environment, evenly apply the blue-printing liquid on the surface of the vegetable tanned leather, or use the blue-printing liquid to paint on the surface of the vegetable tanned leather, or use the blue-printing liquid to print on the surface of the vegetable tanned leather,

[0007] Then let it stand and dry or blow it dry under cool wind conditions to obtain a base plate;

[0008] S3, exposure: placing the shielding object on the base plate and exposing it under the ultraviolet lamp, or directly placing the base plate under the ultraviolet lamp and exposing it.

[0009] Preferably, the application method further comprises the following steps:

[0010] S4, post-treatment: the exposed vegetable tanned leather product is washed with water and then immersed in an acidic solution.

[0011] Preferably, in step S4, the pH value of the acidic solution is 4-6;

[0012] Preferably, in step S4, the vegetable tanned leather product is immersed in the acidic solution for 10-30 min;

[0013] Preferably, the ratio of solution A to solution B is 1:1;

[0014] The concentration of solution A is 0.05-0.3 g / mL -1The concentration of solution B is 0.02-0.12 g / mL -1 .

[0015] Preferably, the power of the ultraviolet lamp is a1 W, the distance between the ultraviolet lamp and the bottom plate is a2 cm, the exposure time is a3 min, and a1, a2 and a3 satisfy 0.6<a1 x a3 / a2<9.

[0016] Preferably, the power of the ultraviolet lamp is 1-15W.

[0017] Preferably, the distance between the ultraviolet lamp and the bottom plate is 10-100 cm.

[0018] Preferably, the exposure time is 5-60 min.

[0019] Preferably, the shielding material includes one or more of dried plant flowers, translucent or opaque sheets, and paper-cuts.

[0020] Preferably, in step S4, the following steps are also included:

[0021] Take out the soaked vegetable tanned leather product and wash it in clean water for 2-3 times, take a water-absorbing sheet to wrap the vegetable tanned leather product, dry it at room temperature, and replace the water-absorbing sheet every 6-8 hours;

[0022] Take the dried vegetable tanned leather product, apply oil on its surface and then dry it.

[0023] Compared with the prior art, the beneficial effects of this application are:

[0024] (1) This proposal pioneered the application of the cyanotype process to vegetable tanned leather, effectively expanding the diversity of materials used in the cyanotype process, providing a theoretical basis for the artistic creation of vegetable tanned leather, and helping to stimulate the design creativity of artists in this field.

[0025] (2) By further studying the combination of blue-printing technology and vegetable tanned leather, this program explored the factors that affect the application effect of blue-printing technology on vegetable tanned leather, and obtained the factors that have a greater impact on the application of blue-printing technology on vegetable tanned leather and their corresponding specific orders of magnitude, providing a favorable theoretical basis for research in this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1 is a flow chart of an application method of one embodiment of the present application;

[0028] Figure 2 This is an imaging effect diagram of Example 1 of the present application. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention:

[0030] In order to further understand the content, features and effects of the invention of this application, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0031] The present application provides an application method of a blue-printing process on vegetable-tanned leather, and the application method comprises the following steps: preparation of blue-printing liquid: mixing solution A and solution B in a light-proof environment and stirring evenly to obtain the blue-printing liquid; the solution A is ammonium ferric citrate, and the solution B is potassium ferrocyanide; coating: taking vegetable-tanned leather, in a light-proof environment, evenly applying the blue-printing liquid on the surface of the vegetable-tanned leather, or using the blue-printing liquid to paint on the surface of the vegetable-tanned leather, or applying the blue-printing liquid to the surface of the vegetable-tanned leather for rubbing; then standing to dry or blowing dry under cool wind conditions to obtain a base plate; exposure: placing a shielding object on the base plate and exposing it under an ultraviolet lamp, or directly placing the base plate under an ultraviolet lamp for exposure; this scheme innovatively applies the blue-printing process to vegetable-tanned leather, effectively expanding the diversity of materials applied to the blue-printing process, providing a theoretical basis for artistic creation of vegetable-tanned leather, and stimulating the design creativity of artists in this field.

[0032] In order to better understand the application method of the blue-printing process on vegetable tanned leather in this application, the application method is further explained as follows:

[0033] See also Figure 1 A method for applying a blue-printing process to vegetable tanned leather according to an embodiment of the present invention comprises the following steps:

[0034] S1. Preparation of blue-printing solution: Solution A and solution B are mixed and stirred in a light-proof environment to obtain the blue-printing solution; the solution A is ammonium ferric citrate, and the solution B is potassium ferrocyanide; it is understood that under the action of sunlight, the ammonium ferric citrate will be reduced to ferrous citrate, and react with potassium ferrocyanide to generate water-insoluble blue ferrous ferrocyanide, which is precipitated on the bottom plate, while the part that is not exposed to sunlight, that is, the part that does not produce a chemical reaction, is dissolved in water, and then the divalent ions in the mixed solution of ammonium ferric citrate and potassium ferrocyanide are washed away and oxidized after exposure to light; preparing the blue-printing solution in a light-proof environment in advance can prevent the blue-printing solution from reacting prematurely when exposed to light, thereby affecting subsequent blue-printing imaging.

[0035] S2. Coating: Take vegetable tanned leather, and in a light-proof environment, evenly apply the blue-based liquid to the surface of the vegetable tanned leather, or use the blue-based liquid to paint on the surface of the vegetable tanned leather, or apply the blue-based liquid to the surface of the vegetable tanned leather for rubbing; then let it stand to dry or blow it dry under cool wind conditions to obtain a base plate; it can be understood that evenly applying the blue-based liquid to the surface of the vegetable tanned leather can ensure that the subsequent imaging image is more uniform and the imaging effect is guaranteed; this solution also provides a variety of imaging ideas, such as directly using the blue-based liquid for painting, and finally the pattern of the painted work can be directly presented; in other application methods, some rubbing tools can also be used to rub the blue-based liquid on the vegetable tanned leather, and finally the pattern to be rubbed is presented.

[0036] S3. Exposure: Place a shielding object on the base plate and expose it under a UV lamp, or directly place the base plate under a UV lamp for exposure; it can be understood that when the base plate adopts the method of evenly applying the above-mentioned blue-sensitive liquid on the surface of the vegetable tanned leather, the entire base plate is coated with the blue-sensitive liquid. At this time, the shielding object can be placed on the base plate. When the UV lamp is irradiated on the base plate, the shielded part does not react, while the unshielded part reacts to produce precipitation. After washing, the shielded part appears blank, and finally cooperates with the precipitated color-developing part to form a pattern; this scheme uses UV lamps for irradiation instead of natural light, which can make the color development and imaging effect more controllable, and finally can more flexibly control the required imaging effect, and manufacturers can also make more flexible adjustments according to actual needs.

[0037] S4. Post-treatment: Wash the exposed vegetable tanned leather product with water and then soak it in an acidic solution. It can be understood that the blue-solution is alkaline, and the vegetable tanned leather is weakly alkaline after the blue-solution treatment. After drying, the texture of the vegetable tanned leather feels harder, the leather surface appears firm, and the elasticity is relatively low. This kind of vegetable tanned leather with a harder texture treated by the blue-solution process can be used as a coaster and other products. The elasticity requirements of the vegetable tanned leather are relatively low, and there is no need to perform major shaping on the finger softness. However, in some application scenarios, such as luggage products, the texture is relatively Hard vegetable tanned leather is not suitable for the production of luggage and other products, because during the shaping process, the vegetable tanned leather is prone to bending and cracking, which ultimately affects the quality of the finished product. In this solution, the vegetable tanned leather is further treated with a weak acid neutralization treatment so that the treated vegetable tanned leather is weakly acidic as a whole. At this time, the vegetable tanned leather treated with a weak acid has a softer overall texture after drying, and the leather surface looks softer and has better elasticity, thereby meeting the shaping needs of some products such as luggage for vegetable tanned leather, effectively expanding the application of vegetable tanned leather treated with the blue-drying process, and making it more practical.

[0038] In one embodiment, in step S4, the pH value of the acidic solution is 4-6; it can be understood that this solution uses a weakly acidic solution to soak the vegetable tanned leather product. When the acidity is too strong, it will damage the vegetable tanned leather, ultimately affecting the product quality of the vegetable tanned leather.

[0039] In one embodiment, in step S4, the vegetable tanned leather product is immersed in the acidic solution for 10-30 minutes; it is understandable that if the vegetable tanned leather product is immersed in the acidic solution for too long, it will affect the texture of the vegetable tanned leather, not only destroying the protein structure of the vegetable tanned leather, but also forming a certain foaming effect, which will ultimately affect the product quality of the vegetable tanned leather product; and if the immersion time is too short, the acid treatment effect of the vegetable tanned leather is not obvious, and ultimately the texture of the vegetable tanned leather is still hard, which is not conducive to subsequent shaping operations.

[0040] In one embodiment, the ratio of solution A to solution B is 1:1.

[0041] In one embodiment, the concentration of solution A is 0.05-0.3 g / mL -1 , the concentration of solution B is 0.02-0.12g / mL -1It is understandable that the concentration of solution A and solution B determines the concentration of the final blue-printing solution. When the concentration of the blue-printing solution is too low, it will lead to unclear development and affect the final quality of the blue-printing product; when the concentration of the blue-printing solution is too high, it will easily cause overexposure. Overexposure will make some details of the final development, especially the dark parts, not show clearly, affecting the final quality of the blue-printing product; it is understandable that traditional blue-printing processes are mostly used on paper, and the blue-printing process is rarely used on vegetable tanned leather. Compared with paper, it is more difficult to show the details of vegetable tanned leather. Therefore, how to control the application of the blue-printing process on vegetable tanned leather and the control of the details of the final product are a major difficulty of this application method.

[0042] In one embodiment, the power of the UV lamp is a1 W, the distance between the UV lamp and the base plate is a2 cm, the exposure time is a3 min, a1a2 and the above 3 satisfy 0.6<a1 x a3 / a2<9; it can be understood that this scheme has conducted a more in-depth study on the relationship between the power of the UV lamp, the distance between the UV lamp and the base plate, and the exposure time, and found that when the relationship between the three satisfies the above relationship, the final blue-printing quality on the vegetable tanned leather is higher, the exposure is appropriate, and the contour details are clearer.

[0043] In one embodiment, the power of the UV lamp is 1-15W; it is understandable that if the power of the UV lamp is too low, in order to ensure the exposure quality, the exposure time needs to be extended, affecting the production efficiency; when the power of the UV lamp is too high, although the exposure efficiency is improved, it is also easy to cause overexposure, affecting the final imaging quality on the vegetable tanned leather.

[0044] In one embodiment, the distance between the UV lamp and the base plate is 10-100 cm. It is understandable that if the distance between the UV lamp and the base plate is too long, in order to ensure clear imaging, the power of the UV lamp needs to be increased, which consumes energy and may also require extended exposure time, affecting production efficiency.

[0045] In one embodiment, the exposure time is 5-60 minutes; it is understandable that the longer the exposure time is, the less conducive it is to improving production efficiency, and the shorter the exposure time is, the higher the power requirement for the UV lamp is, and the risk of overexposure will increase accordingly, which is not conducive to the control of yield rate.

[0046] Furthermore, during the exposure operation, a transparent acrylic plate can be used to clamp both sides of the vegetable tanned leather to ensure that the vegetable tanned leather can receive light evenly, thereby ensuring the exposure quality.

[0047] In one embodiment, the obstruction includes one or more of dried plant flowers, translucent or opaque sheets, and paper-cuts; that is, the operation can adopt the combination of concentrated materials, and in some translucent materials, a gradient visual effect can be presented.

[0048] In one embodiment, in step S4, the following steps are also included: taking out the soaked vegetable tanned leather product and washing it in clean water for 2-3 times, wrapping the vegetable tanned leather product with a water-absorbing sheet, drying it at room temperature, and replacing the water-absorbing sheet every 6-8 hours; taking the dried vegetable tanned leather product, applying an oily substance on its surface and then drying it; it can be understood that there is still a certain amount of acidic liquid attached to the surface of the soaked vegetable tanned leather, and by washing it in clean water for 2-3 times, the acidic liquid on it can be effectively removed, making the surface of the vegetable tanned leather cleaner and facilitating longer storage; and wrapping the vegetable tanned leather product with a water-absorbing sheet, drying it at room temperature, and replacing the water-absorbing sheet every 6-8 hours. Replacing the absorbent sheet ensures that the vegetable tanned leather can be dried quickly. In this process, the drying time of the finished vegetable tanned leather is reduced, aiming to control the rapid volatilization of its moisture in a short time, so as to control the volatilization rate of the vegetable tanned leather oil, that is, to accelerate the loss efficiency of the vegetable tanned leather moisture and slow down the loss efficiency of the vegetable tanned leather oil; ultimately, the treated vegetable tanned leather has better softness and elasticity, which is more conducive to subsequent shaping treatment; in addition, this solution also coats the dried vegetable tanned leather product with an oily substance. This method allows the vegetable tanned leather product to absorb a certain amount of oil, further replenish the oil lost in the processing of the vegetable tanned leather, and ensure its softness and elasticity.

[0049] Further, in some embodiments, the oily substance includes but is not limited to leather care oil.

[0050] Furthermore, the water-absorbent sheet material includes but is not limited to water-absorbent cloth.

[0051] Furthermore, in some embodiments, hard plates can be further arranged on the upper and lower sides of the absorbent sheet, and the vegetable tanned leather wrapped with absorbent cloth can be clamped between the hard plates, and the vegetable tanned leather can be pressed by heavy objects; it is understandable that by further pressing the vegetable tanned leather during the drying process, the vegetable tanned leather can be better shaped, and at the same time, the precipitation of water can be better promoted, and the efficiency of water loss can be further improved, thereby better improving the quality of the finished product of the vegetable tanned leather after drying; further, in some embodiments, the above operations can be performed in a cool environment; it is understandable that the vegetable tanned leather drying operation can be performed in a light-proof environment, which can further reduce the influence of light factors on the output quality of the vegetable tanned leather.

[0052] Some specific examples are listed below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0053] Example 1

[0054] S1. Preparation of blue-drying solution: Mix solution A and solution B in a light-proof environment and stir evenly to obtain the blue-drying solution; the concentration of solution A is 0.2 g / mL -1 Ammonium ferric citrate solution, wherein solution B has a concentration of 0.08 g / mL -1 Potassium ferrocyanide solution;

[0055] S2, coating: take vegetable tanned leather, and evenly apply the blue-drying solution on the surface of the vegetable tanned leather in a light-proof environment;

[0056] Then let it stand and dry or blow it dry under cool wind conditions to obtain a base plate;

[0057] S3, exposure: placing the shielding object on the bottom plate and exposing it under a UV lamp; wherein the power of the UV lamp is 3W, the distance between the UV lamp and the bottom plate is 20cm, and the exposure time is 40min;

[0058] S4, post-treatment: washing the exposed vegetable tanned leather product with water, and then soaking it in a formic acid solution with a pH of 5 for 20 minutes;

[0059] Take out the soaked vegetable tanned leather product and wash it in clean water for 2-3 times, take a water-absorbing sheet to wrap the vegetable tanned leather product, dry it at room temperature, and replace the water-absorbing sheet every 6-8 hours;

[0060] Take the dried vegetable tanned leather product, apply oil on its surface and then dry it.

[0061] Example 2

[0062] S1. Preparation of blue-drying solution: Mix solution A and solution B in a light-proof environment and stir evenly to obtain the blue-drying solution; the concentration of solution A is 0.05 g / mL -1 Ammonium ferric citrate solution, wherein solution B has a concentration of 0.02 g / mL -1 Potassium ferrocyanide solution;

[0063] S2, coating: take vegetable tanned leather, and evenly apply the blue-drying solution on the surface of the vegetable tanned leather in a light-proof environment;

[0064] Then let it stand and dry or blow it dry under cool wind conditions to obtain a base plate;

[0065] S3, exposure: placing the shielding object on the bottom plate and exposing it under a UV lamp; wherein the power of the UV lamp is 5W, the distance between the UV lamp and the bottom plate is 30cm, and the exposure time is 30min;

[0066] S4, post-treatment: washing the exposed vegetable tanned leather product with water, and then soaking it in a formic acid solution with a pH of 6 for 10 minutes;

[0067] Take out the soaked vegetable tanned leather product and wash it in clean water for 2-3 times, take a water-absorbing sheet to wrap the vegetable tanned leather product, dry it at room temperature, and replace the water-absorbing sheet every 6-8 hours;

[0068] Take the dried vegetable tanned leather product, apply oil on its surface and then dry it.

[0069] Example 3

[0070] S1. Preparation of blue-drying solution: Mix solution A and solution B in a light-proof environment and stir evenly to obtain the blue-drying solution; the concentration of solution A is 0.3 g / mL -1 Ammonium ferric citrate solution, wherein solution B has a concentration of 0.12 g / mL -1 Potassium ferrocyanide solution;

[0071] S2, coating: take vegetable tanned leather, and evenly apply the blue-drying solution on the surface of the vegetable tanned leather in a light-proof environment;

[0072] Then let it stand and dry or blow it dry under cool wind conditions to obtain a base plate;

[0073] S3, exposure: placing the shielding object on the bottom plate and exposing it under a UV lamp; wherein the power of the UV lamp is 1W, the distance between the UV lamp and the bottom plate is 100cm, and the exposure time is 60min;

[0074] S4, post-treatment: washing the exposed vegetable tanned leather product with water, and then soaking it in a formic acid solution with a pH of 4 for 30 minutes;

[0075] Take out the soaked vegetable tanned leather product and wash it in clean water for 2-3 times, take a water-absorbing sheet to wrap the vegetable tanned leather product, dry it at room temperature, and replace the water-absorbing sheet every 6-8 hours;

[0076] Take the dried vegetable tanned leather product, apply oil on its surface and then dry it.

[0077] Example 4

[0078] S1. Preparation of blue-drying solution: Mix solution A and solution B in a light-proof environment and stir evenly to obtain the blue-drying solution; the concentration of solution A is 0.05 g / mL -1 Ammonium ferric citrate solution, wherein solution B has a concentration of 0.02 g / mL -1 Potassium ferrocyanide solution;

[0079] S2, coating: take vegetable tanned leather, and evenly apply the blue-drying solution on the surface of the vegetable tanned leather in a light-proof environment;

[0080] Then let it stand and dry or blow it dry under cool wind conditions to obtain a base plate;

[0081] S3, exposure: placing the shielding object on the bottom plate and exposing it under a UV lamp; wherein the power of the UV lamp is 15W, the distance between the UV lamp and the bottom plate is 10cm, and the exposure time is 60min;

[0082] S4, post-treatment: washing the exposed vegetable tanned leather product with water, and then soaking it in a formic acid solution with a pH of 6 for 10 minutes;

[0083] Take out the soaked vegetable tanned leather product and wash it in clean water for 2-3 times, take a water-absorbing sheet to wrap the vegetable tanned leather product, dry it at room temperature, and replace the water-absorbing sheet every 6-8 hours;

[0084] Take the dried vegetable tanned leather product, apply oil on its surface and then dry it.

[0085] Example 5

[0086] S1. Preparation of blue-drying solution: Mix solution A and solution B in a light-proof environment and stir evenly to obtain the blue-drying solution; the concentration of solution A is 0.1 g / mL -1 Ammonium ferric citrate solution, wherein solution B has a concentration of 0.04 g / mL -1 Potassium ferrocyanide solution;

[0087] S2, coating: take vegetable tanned leather, and evenly apply the blue-drying solution on the surface of the vegetable tanned leather in a light-proof environment;

[0088] Then let it stand and dry or blow it dry under cool wind conditions to obtain a base plate;

[0089] S3, exposure: placing the shielding object on the bottom plate and exposing it under a UV lamp; wherein the power of the UV lamp is 15W, the distance between the UV lamp and the bottom plate is 10cm, and the exposure time is 5min;

[0090] S4, post-treatment: washing the exposed vegetable tanned leather product with water, and then soaking it in a formic acid solution with a pH of 6 for 10 minutes;

[0091] Take out the soaked vegetable tanned leather product and wash it in clean water for 2-3 times, take a water-absorbing sheet to wrap the vegetable tanned leather product, dry it at room temperature, and replace the water-absorbing sheet every 6-8 hours;

[0092] Take the dried vegetable tanned leather product, apply oil on its surface and then dry it.

[0093] Comparative Example 1: The processing process of Comparative Example 1 is basically the same as that of Example 1, but step S4 of the comparative example does not include the step of immersing in an acidic solution, but only uses clean water for washing after exposure.

[0094] Comparative Example 2: The treatment process of Comparative Example 2 is basically the same as that of Example 1, but an acidic solution with a pH of 3 is used in step S4 of the comparative example.

[0095] Comparative Example 3: The processing process of Comparative Example 3 is basically the same as that of Example 1. The power of the UV lamp in Comparative Example 3 is 20 W, the distance between the UV lamp and the base plate is 10 cm, and the exposure time is 60 min.

[0096] Comparative Example 4: The processing process of Comparative Example 4 is basically the same as that of Example 1, and Comparative Example 4 does not include the following steps: "taking out the soaked vegetable tanned leather product and washing it in clean water for 2-3 times, taking a water-absorbing sheet to wrap the vegetable tanned leather product, drying it at room temperature, and replacing the water-absorbing sheet every 6-8 hours;

[0097] Take the dried vegetable tanned leather product, apply oil on its surface and then dry it.

[0098] See also Figure 2 , Figure 2 The imaging effect of the vegetable tanned leather in Example 1 shows that the imaging edge is clearly visible and the imaging quality is good. Further analysis of the comparative examples shows that in Comparative Example 1, the acid immersion step is omitted, and the final vegetable tanned leather is weakly alkaline. The vegetable tanned leather after drying feels harder, and the leather surface looks firmer and has less elasticity. The vegetable tanned leather in Example 1 is weakly acidic, and the vegetable tanned leather after drying feels softer, and the leather surface looks looser and has better elasticity. The final vegetable tanned leather product in Comparative Example 2 is looser, and although it is softer, the overall elasticity is poor and it is not tight enough. The edges of the dark details in the imaging results of Comparative Example 3 are not clear enough. The imaging quality in Comparative Example 4 is better than that in Comparative Examples 1-3, but after further post-processing, compared with Comparative Example 4, the vegetable tanned leather of the product in Example 1 is more shiny, softer and more elastic.

[0099] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0100] The above description is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application are within the scope of the technical solution of the present application.

Claims

1. A method for applying a blue-drying process to vegetable tanned leather, characterized in that: The application method comprises the following steps: S1. Preparation of blue-drying solution: Mix solution A and solution B in a light-proof environment and stir evenly to obtain the blue-drying solution; the solution A is ammonium ferric citrate, and the solution B is potassium ferrocyanide; S2, coating: take vegetable tanned leather, and in a light-proof environment, evenly apply the blue-tanning liquid on the surface of the vegetable tanned leather, or use the blue-tanning liquid to paint on the surface of the vegetable tanned leather, or use the blue-tanning liquid to make rubbings on the surface of the vegetable tanned leather; Then let it stand and dry or blow it dry under cool wind conditions to obtain a base plate; S3, exposure: placing the shielding object on the base plate and exposing it under the ultraviolet lamp, or directly placing the base plate under the ultraviolet lamp for exposure; The ratio of solution A to solution B is 1:1; The concentration of solution A is 0.05-0.3 g / mL -1 The concentration of solution B is 0.02-0.12 g / mL -1 ; The power of the ultraviolet lamp is a1 W, the distance between the ultraviolet lamp and the bottom plate is a2 cm, the exposure time is a3 min, and a1, a2 and a3 satisfy 0.6 < <9; The power of the ultraviolet lamp is 1-15W; The distance between the ultraviolet lamp and the bottom plate is 10-100cm; The exposure time is 5-60 min.

2. The method for applying the blue-printing process to vegetable tanned leather according to claim 1 is characterized in that: The application method further comprises the following steps: S4. Post-treatment: Wash the exposed vegetable tanned leather product with water and then soak it in an acidic solution.

3. The method for applying the blue-drying process to vegetable tanned leather according to claim 2, characterized in that: In step S4, the pH value of the acidic solution is 4-6.

4. The method for applying the blue-drying process to vegetable tanned leather according to claim 2 or 3, characterized in that: In step S4, the vegetable tanned leather product is immersed in the acidic solution for 10-30 minutes.

5. The method for applying the blue-drying process to vegetable tanned leather according to claim 4, characterized in that: In the step S4, the following steps are also included: Take out the soaked vegetable tanned leather product and wash it in clean water for 2-3 times, take a water-absorbing sheet to wrap the vegetable tanned leather product, dry it at room temperature, and replace the water-absorbing sheet every 6-8 hours; Take the dried vegetable tanned leather product, apply oil on its surface and then dry it.

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