Leather softening processing method

Abstract

The invention relates to the technical field of leather processing, in particular to a leather softening processing method which comprises the following steps: unhairing and degreasing raw leather to obtain bare leather; judging whether the processing of the bare skin meets a preset standard or not according to the bare skin quality evaluation value; stirring and rotating the bare leather meeting the preset standard in a rotary drum to obtain soaked soft leather; when it is judged that the processing of the soaked soft leather does not meet the preset standard according to the permeation uniformity characteristic value, the content of a softening agent in the rotary drum is increased, or whether the processing of the soaked soft leather meets the preset standard or not is judged secondarily according to the soft characteristic value; the soaked soft leather meeting the preset standard is put into an oscillating staking machine to be oscillated and stretched, and leather is obtained; judging whether the processing of the leather meets a preset standard or not according to the bending springback characteristic value; leather meeting the preset standard is polished and dried, softened leather is obtained, and the leather softening processing efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of leather processing, in particular to a leather softening processing method. Background Art

[0002] Leather softening is an important process in the leather making process, which aims to make the leather softer, smoother and finer in grain, and improve its sensory properties, breathability and hygiene. This step is crucial to the production and quality of leather products. Leather softening can be done by physical and chemical methods. Among them, the physical method mainly changes the softness of the leather through mechanical action, temperature control and other methods; the chemical method mainly changes the chemical structure of the leather by adding softeners to achieve leather softening.

[0003] Chinese Patent Publication (Announcement) No.: CN115044714B discloses a leather softening processing system, including a base and a box body, a box body is fixedly installed on the upper end surface of the base, a soaking liquid is contained in the box body, an outer cylinder is fixedly installed on the box body, a feed port is opened on the upper end of the outer surface of the outer cylinder, and a cylinder cover is hingedly installed at the feed port, a driving mechanism is arranged on the rear end surface of the outer cylinder, a squeezing mechanism is arranged at the inner center position of the outer cylinder, and the driving mechanism is connected to the squeezing mechanism, and an adjustment component is arranged between the squeezing mechanism and the inner bottom end of the outer cylinder, by arranging the driving mechanism, the squeezing mechanism and the adjustment component in the device, the driving mechanism cooperates with the squeezing mechanism and the adjustment component to squeeze the leather placed inside the squeezing mechanism, and the leather is repeatedly squeezed in the soaking liquid for a certain period of time, which can better absorb the liquid in the soaking liquid, and achieve an excellent soaking and softening effect. It can be seen that the softening of leather in the prior art is only physical squeezing and soaking, and the softening processing parameters of leather cannot be adjusted accordingly according to the difference in leather softening quality, thereby resulting in poor leather softening processing efficiency. Summary of the invention

[0004] To this end, the present invention provides a leather softening processing method to overcome the problem that the leather softening in the prior art is only physical squeezing and soaking and the leather softening processing parameters cannot be adjusted accordingly according to the differences in leather conversion quality characteristics, thereby resulting in poor leather softening processing efficiency.

[0005] To achieve the above object, the present invention provides a leather softening processing method, comprising:

[0006] Step S1, adding a depilatory agent into a rotary drum and placing raw hides, starting the rotary drum, and depilating the raw hides under the action of the depilatory agent; after the rotary drum rotates for a preset depilatory time, adding a degreasing agent into the rotary drum, and after the rotary drum rotates for a preset degreasing time, draining and washing are performed to obtain bare hides;

[0007] Step S2, obtaining the fur area ratio and the oil content of the bare skin, obtaining the bare skin quality evaluation value, and determining whether the processing of the bare skin meets the preset standard according to the bare skin quality evaluation value;

[0008] Step S3, adding the bare leather that meets the preset standard into a rotary drum containing a softener and stirring and rotating it, and obtaining the macerated leather after a preset softening time;

[0009] Step S4, setting a plurality of sampling points on the surface of the macerated leather, obtaining the hardness of each sampling point, and obtaining a penetration uniformity characteristic value, and increasing the softener content in the drum when judging that the processing of the macerated leather does not meet the preset standard according to the penetration uniformity characteristic value, or judging whether the processing of the macerated leather meets the preset standard for the second time according to the soft characteristic value;

[0010] Step S5, putting the soaked leather that meets the preset standard into an oscillating stretching machine for oscillation stretching to obtain leather; obtaining the bending rebound characteristic value of the leather, and judging whether the processing of the leather meets the preset standard according to the bending rebound characteristic value;

[0011] Step S6, grinding and drying the leather that meets the preset standards to obtain softened leather.

[0012] Further, the process of determining that the processing of the bare skin does not meet the preset standard according to the bare skin quality evaluation value includes:

[0013] Comparing the bare skin quality evaluation value with a preset bare skin quality threshold;

[0014] If the bare skin quality evaluation value is less than the preset bare skin quality threshold, it is determined that the processing of the bare skin does not meet the preset standard, and the depilatory time and degreasing time of the drum are synchronously increased according to the difference between the bare skin quality evaluation value and the preset bare skin quality threshold;

[0015] The bare skin quality evaluation value is determined based on the hair area ratio and the oil content of the bare skin.

[0016] Furthermore, several time adjustment methods are provided for the synchronous increase of the depilatory time of the rotary drum and the degreasing time, wherein:

[0017] If the bare skin quality difference is less than the first preset bare skin quality difference, the first duration adjustment coefficient is used to synchronously increase the depilatory duration of the rotary drum and the degreasing duration;

[0018] If the bare skin quality difference is greater than or equal to the first preset bare skin quality difference and less than the second preset bare skin quality difference, the second duration adjustment coefficient is used to synchronously increase the depilatory duration of the rotary drum and the degreasing duration;

[0019] If the bare skin quality difference is greater than or equal to the second preset bare skin quality difference, the third time adjustment coefficient is used to synchronously increase the depilatory time of the drum and the degreasing time;

[0020] The bare skin quality difference is the difference between the preset bare skin quality threshold and the bare skin quality evaluation value.

[0021] Further, whether the processing of the macerated leather meets the preset standard is determined according to the penetration uniformity characteristic value, wherein:

[0022] If the penetration uniformity characteristic value is less than a first preset penetration uniformity threshold value, it is determined that the processing of the macerated leather does not meet the preset standard, and the softener content in the drum is increased according to the difference between the first preset penetration uniformity threshold value and the penetration uniformity characteristic value;

[0023] If the penetration uniformity characteristic value is greater than or equal to the first preset penetration uniformity threshold and less than the second preset penetration uniformity threshold, it is determined that the processing of the macerated leather does not meet the preset standard, and a second determination is made based on the soft characteristic value whether the processing of the macerated leather meets the preset standard;

[0024] If the penetration uniformity characteristic value is greater than or equal to the second preset penetration uniformity threshold value, it is determined that the processing of the macerated leather meets the preset standard, and the macerated leather that meets the preset standard is placed in the oscillating softening machine;

[0025] The penetration uniformity characteristic value is determined by the hardness of each sampling point of the macerated leather.

[0026] Further, a second determination is made based on the soft characteristic value whether the processing of the macerated leather meets the preset standard, wherein:

[0027] If the soft characteristic value is less than the preset soft characteristic value, it is determined that the processing of the macerated leather does not meet the preset standard, and the stirring speed of the drum is increased according to the difference;

[0028] If the soft characteristic value is greater than or equal to the preset soft characteristic value, it is determined that the processing of the macerated leather meets the preset standard, and the macerated leather that meets the preset standard is placed in the oscillating softening machine.

[0029] Furthermore, the process of obtaining the soft characteristic value includes:

[0030] The thickness of a plurality of sampling points is measured, and an average initial thickness is calculated and recorded as a first thickness;

[0031] Using a leather thickness tester, applying a preset pressure to each sampling point and measuring the thickness of the leather when the preset pressure is applied, and calculating an average thickness under the preset pressure, which is recorded as the second thickness;

[0032] The soft characteristic value is the difference between the first thickness and the second thickness.

[0033] Furthermore, whether the leather processing meets the preset standard is determined according to the bending rebound characteristic value of the leather, wherein:

[0034] If the bending rebound characteristic value is less than the preset bending rebound threshold value, it is determined that the leather processing does not meet the preset standard, and the vibration frequency of the oscillation softening machine is increased according to the difference between the preset bending rebound threshold value and the bending rebound characteristic value;

[0035] If the bending rebound characteristic value is greater than or equal to the preset bending rebound threshold value, it is determined that the processing of the leather meets the preset standard, and the leather that meets the preset standard is polished and dried.

[0036] Furthermore, the process of obtaining the bending springback characteristic value includes:

[0037] Use a leather bending tester to bend the leather placed horizontally at a preset angle;

[0038] After maintaining the preset angle for a preset time, record the bending recovery angle;

[0039] The ratio of the bending recovery angle to the bending preset angle is recorded as the bending rebound characteristic value.

[0040] Furthermore, the increase amplitude of the vibration frequency of the oscillation softening machine is positively correlated with the bending rebound difference, wherein the bending rebound difference is the difference between a preset bending rebound threshold and a bending rebound characteristic value.

[0041] Further, under the first preset condition, several frequency correction methods are provided for the correction of the vibration frequency of the oscillation softening machine, wherein:

[0042] If the surface gloss difference is less than a first preset surface gloss difference, the vibration frequency of the oscillation stretching machine is corrected using a first correction coefficient;

[0043] If the surface gloss difference is greater than or equal to the first preset surface gloss difference and less than the second preset surface gloss difference, the vibration frequency of the oscillation stretching machine is corrected using the second correction coefficient;

[0044] If the surface gloss difference is greater than or equal to the second preset surface gloss difference, the vibration frequency of the oscillation stretching machine is corrected using a third correction coefficient;

[0045] The first preset condition is that the surface glossiness of the leather is less than a preset surface glossiness after the vibration frequency of the oscillation softening machine is increased;

[0046] The surface glossiness of the leather is obtained by glossiness values ​​of several sampling points.

[0047] Compared with the prior art, the beneficial effects of the present invention are that the present invention verifies the depilatory and degreasing effects of bare leather through the bare leather quality evaluation value, and removes impurities and grease on the surface of the bare leather; evaluates the penetration uniformity of the softener in the soaked leather through the penetration uniformity characteristic value, ensures the uniform penetration and softening of the soaked leather by the softener during the leather processing, and further verifies the softening processing effect of the soaked leather through the softness characteristic value; accurately monitors the softening quality of the leather through the bending rebound characteristic value and adopts corresponding adjustment strategies according to the comparison results, further improves the extensibility and softness of the leather, and also helps to flatten and shape the leather, thereby improving the leather softening processing efficiency.

[0048] Furthermore, the present invention obtains the bare skin quality evaluation value by obtaining the fur area ratio and the oil content of the bare skin, thereby providing a specific quantitative indicator for the evaluation of the bare skin quality, thereby avoiding the subjectivity in the bare skin quality evaluation method.

[0049] Furthermore, when the present invention determines through the bare skin quality evaluation value that the processing of the bare skin does not meet the preset standard, the dehairing time and the degreasing time of the drum are increased. Through the bare skin quality evaluation value, the processing quality of the bare skin in the processing process can be accurately evaluated, and problems can be discovered and solved in time, thereby improving the processing quality control level.

[0050] Furthermore, the present invention provides several time adjustment modes for synchronously increasing the depilation time and the degreasing time of the drum, thereby achieving precise control of the depilation time and the degreasing time of the drum and providing an intelligent level.

[0051] Furthermore, the present invention determines whether the processing of the macerated leather meets the preset standard according to the penetration uniformity characteristic value, monitors the processing of the macerated leather in real time, and realizes timely adjustment of the macerated leather processing parameters.

[0052] Furthermore, the present invention sets a softness characteristic value and determines whether the processing of the macerated leather meets the preset standard based on the softness characteristic value. The softness characteristic value is a quantitative indicator used to describe the softness of the macerated leather after processing, thereby achieving accurate evaluation of the processing quality of the macerated leather.

[0053] Furthermore, the present invention determines whether the processing of the leather meets the preset standards based on the bending rebound characteristic value of the leather. The bending rebound characteristic value is a quantitative indicator used to describe the ability of the leather to return to its original shape after being subjected to a bending force. It reflects the flexibility and elasticity of the leather, thereby improving the efficiency of the leather softening process.

[0054] Furthermore, the present invention provides several frequency correction methods for correcting the vibration frequency of the oscillation softening machine, so that the leather softening process is more flexible and accurate, and can adapt to the characteristics and processing requirements of different types of leather, thereby improving the leather softening quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A step diagram of a leather softening method according to an embodiment of the present invention;

[0056] Figure 2 A flow chart of an embodiment of the present invention for determining whether the processing of bare skin meets a preset standard;

[0057] Figure 3 This is a flow chart of determining whether the processing of macerated leather meets preset standards according to an embodiment of the present invention;

[0058] Figure 4 This is a flow chart of an embodiment of the present invention for determining whether leather processing meets preset standards. DETAILED DESCRIPTION

[0059] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0060] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0061] It should be pointed out that the data in this embodiment are obtained by comprehensive analysis and evaluation of the historical test data of the present invention three months before this test and the corresponding historical test results. It can be understood by those skilled in the art that the method of the present invention can determine the above parameters for a single item by selecting the value with the highest proportion as the preset standard parameter according to the data distribution, using weighted summation to use the obtained value as the preset standard parameter, substituting each historical data into a specific formula and using the value obtained by the formula as the preset standard parameter or other selection methods, as long as the method of the present invention can clearly define different specific situations in the single determination process through the obtained values.

[0062] See also Figure 1 , Figure 2 , Figure 3 as well as Figure 4 As shown, they are respectively embodiments of the present invention.

[0063] The embodiment of the present invention provides a leather softening processing method, comprising:

[0064] Step S1, adding a depilatory agent into a rotary drum and placing raw hides, starting the rotary drum, and depilating the raw hides under the action of the depilatory agent; after the rotary drum rotates for a preset depilatory time of 3.3 hours, adding a degreasing agent into the rotary drum, and after the rotary drum rotates for a preset degreasing time of 6 hours, draining and washing are performed to obtain bare hides;

[0065] Step S2, obtaining the fur area ratio and the oil content of the bare skin, obtaining the bare skin quality evaluation value, and determining whether the processing of the bare skin meets the preset standard according to the bare skin quality evaluation value;

[0066] Step S3, adding the bare leather that meets the preset standard into a rotary drum containing a softener and stirring and rotating it, and obtaining the macerated leather after a preset softening time of 50 minutes;

[0067] Step S4, setting a plurality of sampling points on the surface of the macerated leather, obtaining the hardness of each sampling point, and obtaining a penetration uniformity characteristic value, and increasing the softener content in the drum when judging that the processing of the macerated leather does not meet the preset standard according to the penetration uniformity characteristic value, or judging whether the processing of the macerated leather meets the preset standard for the second time according to the soft characteristic value;

[0068] Step S5, putting the soaked leather that meets the preset standard into an oscillating stretching machine for oscillation stretching to obtain leather; obtaining the bending rebound characteristic value of the leather, and judging whether the processing of the leather meets the preset standard according to the bending rebound characteristic value;

[0069] Step S6, grinding and drying the leather that meets the preset standards to obtain softened leather.

[0070] In this embodiment, the depilatory agent is a protease depilatory agent, the degreasing agent is a surfactant degreasing agent, and the softening agent is an enzyme preparation, which is not specifically limited and only needs to meet the leather softening processing requirements.

[0071] Specifically, the process of determining that the processing of the bare skin does not meet the preset standards based on the bare skin quality evaluation value includes:

[0072] Comparing the bare skin quality evaluation value with a preset bare skin quality threshold;

[0073] If the bare skin quality evaluation value is less than the preset bare skin quality threshold value of 0.58, it is determined that the processing of the bare skin does not meet the preset standard, and the depilatory time and degreasing time of the drum are synchronously increased according to the difference between the bare skin quality evaluation value and the preset bare skin quality threshold value;

[0074] The process of obtaining the bare skin quality evaluation value includes:

[0075] The image processing software processes the bare skin image, identifies the fur and leather parts in the image, calculates the fur area ratio, and multiplies it by the preset fur area ratio weight 0.43 to obtain the first evaluation value;

[0076] The oil content in the bare skin is measured by a skin oil detector, and multiplied by a preset oil content weight of 0.57 to obtain a second evaluation value;

[0077] The bare skin quality evaluation value is the sum of the first evaluation value and the second evaluation value.

[0078] Specifically, several time adjustment methods are provided for the synchronous increase of the depilatory time and the degreasing time of the drum, wherein:

[0079] If the bare skin quality difference is less than the first preset bare skin quality difference of 0.23, the first duration adjustment coefficient of 1.04 is used to synchronously increase the depilatory duration of the rotary drum and the degreasing duration;

[0080] If the bare skin quality difference is greater than or equal to the first preset bare skin quality difference and less than the second preset bare skin quality difference of 0.46, then the second duration adjustment coefficient of 1.06 is used to synchronously increase the depilatory duration of the rotary drum and the degreasing duration;

[0081] If the bare skin quality difference is greater than or equal to the second preset bare skin quality difference, the third duration adjustment coefficient of 1.08 is used to synchronously increase the depilatory duration of the rotary drum and the degreasing duration;

[0082] The bare skin quality difference is the difference between the preset bare skin quality threshold and the bare skin quality evaluation value.

[0083] Specifically, whether the processing of the macerated leather meets the preset standard is determined based on the penetration uniformity characteristic value, wherein:

[0084] If the penetration uniformity characteristic value is less than the first preset penetration uniformity threshold value of 0.45, it is determined that the processing of the macerated leather does not meet the preset standard, and the softener content in the drum is increased according to the difference between the first preset penetration uniformity threshold value and the penetration uniformity characteristic value;

[0085] If the penetration uniformity characteristic value is greater than or equal to the first preset penetration uniformity threshold and less than the second preset penetration uniformity threshold of 0.73, it is determined that the processing of the macerated leather does not meet the preset standard, and a second determination is made based on the soft characteristic value whether the processing of the macerated leather meets the preset standard;

[0086] If the penetration uniformity characteristic value is greater than or equal to the second preset penetration uniformity threshold, it is determined that the processing of the macerated leather meets the preset standard, and the macerated leather meeting the preset standard is placed in the oscillation softening machine;

[0087] The penetration uniformity characteristic value is the ratio between a preset hardness value and an average value of the sum of the hardnesses of the sampling points, and the hardness of the sampling points is obtained by a leather hardness tester.

[0088] Specifically, it is determined whether the processing of the macerated leather meets the preset standard based on the soft characteristic value.

[0089] If the soft characteristic value is less than the preset soft characteristic value of 0.23 mm, it is determined that the processing of the macerated leather does not meet the preset standard, and the stirring speed of the drum is increased according to the difference;

[0090] If the soft characteristic value is greater than or equal to the preset soft characteristic value, it is determined that the processing of the macerated leather meets the preset standard, and the macerated leather that meets the preset standard is placed in the oscillating softening machine.

[0091] Specifically, the process of obtaining the soft characteristic value includes:

[0092] The thickness of a plurality of sampling points is measured, and an average initial thickness is calculated and recorded as a first thickness;

[0093] Use a leather thickness tester to apply a preset pressure to each sampling point and measure the thickness of the leather when the preset pressure of 5N is applied, and calculate the average thickness at the preset pressure, which is recorded as the second thickness;

[0094] The soft characteristic value is the difference between the first thickness and the second thickness.

[0095] Specifically, whether the leather processing meets the preset standard is determined according to the bending rebound characteristic value of the leather, wherein:

[0096] If the bending rebound characteristic value is less than the preset bending rebound threshold value of 0.87, it is determined that the leather processing does not meet the preset standard, and the vibration frequency of the oscillation softening machine is increased according to the difference between the preset bending rebound threshold value and the bending rebound characteristic value;

[0097] If the bending rebound characteristic value is greater than or equal to the preset bending rebound threshold value, it is determined that the processing of the leather meets the preset standard, and the leather that meets the preset standard is polished and dried.

[0098] Specifically, the process of obtaining the bending springback characteristic value includes:

[0099] Use a leather bending tester to bend the horizontally placed leather to a preset angle of 90°;

[0100] After maintaining the preset angle for a preset time of 10 minutes, record the bending recovery angle;

[0101] The ratio of the bending recovery angle to the bending preset angle is recorded as the bending rebound characteristic value.

[0102] Specifically, the increase amplitude of the vibration frequency of the oscillation softening machine is positively correlated with the bending rebound difference, wherein the positive correlation is, for example, a linear positive correlation or a nonlinear positive correlation, and the slope of the linear positive correlation is not specifically limited. It can be understood that the larger the bending rebound difference is, the larger the vibration frequency amplitude of the oscillation softening machine is; the bending rebound difference is the difference between the preset bending rebound threshold and the bending rebound characteristic value.

[0103] Specifically, under the first preset condition, several frequency correction methods are provided for the correction of the vibration frequency of the oscillation softening machine, wherein:

[0104] If the surface gloss difference is less than the first preset surface gloss difference 8GU, the vibration frequency of the oscillation stretching machine is corrected using a first correction coefficient of 0.98;

[0105] If the surface gloss difference is greater than or equal to the first preset surface gloss difference and less than the second preset surface gloss difference 16GU, the vibration frequency of the oscillation stretching machine is corrected using a second correction coefficient of 0.96;

[0106] If the surface gloss difference is greater than or equal to the second preset surface gloss difference, the vibration frequency of the oscillation stretching machine is corrected using a third correction coefficient of 0.94;

[0107] The first preset condition is that the surface glossiness of the leather is less than a preset surface glossiness of 60GU after the vibration frequency of the oscillation softening machine is increased;

[0108] The surface glossiness of the leather is obtained by the glossiness values ​​of several sampling points, and the glossiness of each sampling point is obtained by a gloss meter;

[0109] The surface glossiness of the leather is the ratio between the average value of the sum of the glossiness values ​​of a plurality of sampling points and a preset glossiness.

[0110] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A leather softening method, characterized in that: Step S1, adding a depilatory agent into a rotary drum and placing raw hides, starting the rotary drum, and depilating the raw hides under the action of the depilatory agent; after the rotary drum rotates for a preset depilatory time, adding a degreasing agent into the rotary drum, and after the rotary drum rotates for a preset degreasing time, draining and washing are performed to obtain bare hides; Step S2, obtaining the fur area ratio and the oil content of the bare skin, obtaining the bare skin quality evaluation value, and determining whether the processing of the bare skin meets the preset standard according to the bare skin quality evaluation value; Step S3, adding the bare leather that meets the preset standard into a rotary drum containing a softener and stirring and rotating it, and obtaining the macerated leather after a preset softening time; Step S4, setting a plurality of sampling points on the surface of the macerated leather, obtaining the hardness of each sampling point, and obtaining a penetration uniformity characteristic value, and increasing the softener content in the drum when judging that the processing of the macerated leather does not meet the preset standard according to the penetration uniformity characteristic value, or judging whether the processing of the macerated leather meets the preset standard for the second time according to the soft characteristic value; Step S5, putting the soaked leather that meets the preset standard into an oscillating stretching machine for oscillation stretching to obtain leather; obtaining the bending rebound characteristic value of the leather, and judging whether the processing of the leather meets the preset standard according to the bending rebound characteristic value; Step S6, grinding and drying the leather that meets the preset standards to obtain softened leather.

2. The leather softening method according to claim 1, characterized in that: The process of judging whether the processing of the bare skin does not meet the preset standards according to the bare skin quality evaluation value includes: Comparing the bare skin quality evaluation value with a preset bare skin quality threshold; If the bare skin quality evaluation value is less than the preset bare skin quality threshold, it is determined that the processing of the bare skin does not meet the preset standard, and the depilatory time and degreasing time of the drum are synchronously increased according to the difference between the bare skin quality evaluation value and the preset bare skin quality threshold; The bare skin quality evaluation value is determined based on the hair area ratio and the oil content of the bare skin.

3. The leather softening method according to claim 2, characterized in that: There are several time adjustment methods for synchronously increasing the depilatory time of the drum and the degreasing time, among which: If the bare skin quality difference is less than the first preset bare skin quality difference, the first duration adjustment coefficient is used to synchronously increase the depilatory duration of the rotary drum and the degreasing duration; If the bare skin quality difference is greater than or equal to the first preset bare skin quality difference and less than the second preset bare skin quality difference, the second duration adjustment coefficient is used to synchronously increase the depilatory duration of the rotary drum and the degreasing duration; If the bare skin quality difference is greater than or equal to the second preset bare skin quality difference, the third time adjustment coefficient is used to synchronously increase the depilatory time of the drum and the degreasing time; The bare skin quality difference is the difference between the preset bare skin quality threshold and the bare skin quality evaluation value.

4. The leather softening method according to claim 3, characterized in that: The uniform penetration characteristic value is used to determine whether the processing of the macerated leather meets the preset standard, where: If the penetration uniformity characteristic value is less than a first preset penetration uniformity threshold value, it is determined that the processing of the macerated leather does not meet the preset standard, and the softener content in the drum is increased according to the difference between the first preset penetration uniformity threshold value and the penetration uniformity characteristic value; If the penetration uniformity characteristic value is greater than or equal to the first preset penetration uniformity threshold and less than the second preset penetration uniformity threshold, it is determined that the processing of the macerated leather does not meet the preset standard, and a second determination is made based on the soft characteristic value whether the processing of the macerated leather meets the preset standard; If the penetration uniformity characteristic value is greater than or equal to the second preset penetration uniformity threshold value, it is determined that the processing of the macerated leather meets the preset standard, and the macerated leather that meets the preset standard is placed in the oscillating softening machine; The penetration uniformity characteristic value is determined by the hardness of each sampling point of the macerated leather.

5. The leather softening method according to claim 4, characterized in that: The soft characteristic value is used to determine whether the processing of the macerated leather meets the preset standards. If the soft characteristic value is less than the preset soft characteristic value, it is determined that the processing of the macerated leather does not meet the preset standard, and the stirring speed of the drum is increased according to the difference; If the soft characteristic value is greater than or equal to the preset soft characteristic value, it is determined that the processing of the macerated leather meets the preset standard, and the macerated leather that meets the preset standard is placed in the oscillating softening machine.

6. The leather softening method according to claim 5, characterized in that: The process of obtaining the soft characteristic value includes: The thickness of a plurality of sampling points is measured, and an average initial thickness is calculated and recorded as a first thickness; Using a leather thickness tester, applying a preset pressure to each sampling point and measuring the thickness of the leather when the preset pressure is applied, and calculating an average thickness under the preset pressure, which is recorded as the second thickness; The soft characteristic value is the difference between the first thickness and the second thickness.

7. The leather softening method according to claim 6, characterized in that: According to the bending rebound characteristic value of the leather, it is determined whether the leather processing meets the preset standard, wherein: If the bending rebound characteristic value is less than the preset bending rebound threshold value, it is determined that the leather processing does not meet the preset standard, and the vibration frequency of the oscillation softening machine is increased according to the difference between the preset bending rebound threshold value and the bending rebound characteristic value; If the bending rebound characteristic value is greater than or equal to the preset bending rebound threshold value, it is determined that the processing of the leather meets the preset standard, and the leather that meets the preset standard is polished and dried.

8. The leather softening method according to claim 7, characterized in that: The process of obtaining the bending springback characteristic value includes: Use a leather bending tester to bend the leather placed horizontally at a preset angle; After maintaining the preset angle for a preset time, record the bending recovery angle; The ratio of the bending recovery angle to the bending preset angle is recorded as the bending rebound characteristic value.

9. The leather softening method according to claim 8, characterized in that: The increase amplitude of the vibration frequency of the oscillating stretching machine is positively correlated with the bending rebound difference, wherein the bending rebound difference is the difference between a preset bending rebound threshold and a bending rebound characteristic value.

10. The leather softening method according to claim 9, characterized in that: Under the first preset condition, several frequency correction methods are provided for the correction of the vibration frequency of the oscillation stretching machine, among which: If the surface gloss difference is less than a first preset surface gloss difference, the vibration frequency of the oscillation stretching machine is corrected using a first correction coefficient; If the surface gloss difference is greater than or equal to the first preset surface gloss difference and less than the second preset surface gloss difference, the vibration frequency of the oscillation stretching machine is corrected using the second correction coefficient; If the surface gloss difference is greater than or equal to the second preset surface gloss difference, the vibration frequency of the oscillation stretching machine is corrected using a third correction coefficient; The first preset condition is that the surface glossiness of the leather is less than a preset surface glossiness after the vibration frequency of the oscillation softening machine is increased; The surface glossiness of the leather is obtained by glossiness values ​​of several sampling points.

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