Method for measuring tanning strength of leather cultural relics

Abstract

The present application belongs to the technical field of leather artifact protection, and discloses a kind of efficient non-destructive leather artifact tanning strength determination method.The method uses synchrotron radiation source to obtain the wide-angle X-ray one-dimensional diffraction pattern of leather artifact sample (moisture content 5%-10%), calculates the lateral stacking distance between collagen molecules through the pattern, and calculates the tanning strength according to the lateral stacking distance, realizes the rapid, non-destructive, accurate quantification of leather artifact tanning strength.The method effectively solves the problems of sample scarcity, irregular shape, etc., and provides reliable scientific data support for evaluating the stability of leather artifacts and carrying out preventive protection.

Description

Technical Field

[0001] The invention belongs to the technical field of leather cultural relic protection, and particularly relates to a method for measuring the tanning strength of leather cultural relics. Background Art

[0002] As an important carrier of human civilization, leather artifacts have witnessed the changes in history and the inheritance of culture. They are of great significance for studying human society, promoting cultural exchanges, and exploring ancient crafts. Tanning is a key process for converting raw hides into leather. The accurate measurement of its strength is crucial for evaluating the durability, stability, and corrosion resistance of leather artifacts, thereby providing reliable data support for the formulation of scientific restoration plans. Therefore, it has important value in the field of cultural relic protection and restoration. However, because leather artifacts are fragile and easily affected by environmental factors, the existing detection methods for the tanning strength of modern leather (such as leather shrinkage temperature or thermal denaturation temperature) are not only complicated to operate, but also cause irreversible damage to the artifacts. Therefore, there is an urgent need to develop new methods for quantifying the tanning strength of leather artifacts to fill the technical gap in this field. Summary of the Invention

[0003] In order to solve the problems existing in the background technology, the present invention aims to provide an efficient, practical and non-destructive method for measuring the tanning strength of leather artifacts.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] The determination method of the tanning strength of leather artifacts is as follows:

[0006] The test obtained the synchrotron radiation light source wide-angle X-ray one-dimensional diffraction pattern of the leather artifact sample; the moisture content of the sample was 5%-10%;

[0007] Calculating the lateral stacking distance between sample collagen molecules according to the wide-angle X-ray one-dimensional diffraction pattern of the synchrotron radiation light source;

[0008] The tanning strength of the sample was calculated based on the lateral stacking distance using the formula: S = (1.30-D) / 1.30 × 100%; wherein S is the tanning strength, D is the lateral stacking distance, and 1.30 is the standard lateral stacking distance between untanned skin collagen molecules, expressed in nm.

[0009] Preferably, the distance between the sample and the detector during the synchrotron radiation light source wide-angle X-ray scattering test is 30-50 cm.

[0010] Preferably, the test time of the synchrotron radiation source wide-angle X-ray scattering is 0.1-2 s.

[0011] Preferably, the energy range of wide-angle X-ray scattering of the synchrotron radiation source is 8-15 keV.

[0012] Preferably, the leather artifact samples include any one of aluminum-tanned leather artifacts, iron-tanned leather artifacts, smoke-tanned leather artifacts, oil-tanned leather artifacts, nitrated leather artifacts, nitrate-tanned leather artifacts, parchment artifacts, and shadow puppet artifacts.

[0013] Preferably, the leather artifact sample comprises any one of leather pieces, leather residues and leather particles.

[0014] Preferably, the calculation formula of the lateral stacking distance is: D = 2π / q; wherein q is the abscissa value of the characteristic peak representing the distance between collagen molecules in the one-dimensional spectrum, and the unit is nm. -1 .

[0015] The present invention uses synchrotron radiation light source wide-angle X-ray scattering technology to measure the tanning intensity of leather artifacts. Compared with the existing technology, it has the following advantages:

[0016] (1) Non-destructive protection technology: The use of non-destructive detection methods completely avoids potential risks to the structure of cultural relics, ensures the original state and integrity of cultural relics, and meets the non-destructive standards for cultural relic protection.

[0017] (2) High-efficiency and rapid identification technology: This technology can quickly provide accurate measurement results within 0.1 to 2 seconds, significantly shortening the test cycle, greatly improving measurement efficiency, effectively reducing manpower and time costs, and providing strong support for cultural relics protection work.

[0018] (3) Widely applicable identification technology: This technology is highly adaptable and is not limited by the shape, state or preservation conditions of cultural relics. It does not require complicated pre-processing steps and can be directly applied to the identification of various leather cultural relics, providing a more convenient and efficient testing method for cultural relic protection work. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the measurement of the tanning reaction intensity between tanning agents and collagen using wide-angle X-rays from a synchrotron radiation source. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies has been omitted to avoid unnecessary confusion of the concept of the present invention. In the embodiments, those not indicating specific conditions are carried out according to the conditions of normal conditions or manufacturer's advice. Reagents used or instruments not indicating manufacturers are conventional products that can be purchased commercially.

[0021] Shrinkage temperature or thermal denaturation temperature tests are widely used methods for testing the tanning strength of modern leather. However, these two testing methods are not only cumbersome to operate, but can also cause irreversible damage to cultural relics. Through a large number of synchrotron radiation light source wide-angle X-ray scattering tests, the applicant found that under specific moisture content conditions (5%-10%), the tanning strength of leather cultural relics is positively correlated with the degree of reduction in the lateral stacking distance between their collagen molecules. Specifically, the tanning process involves a chemical cross-linking reaction between tanning agent molecules and collagen molecules. The higher the tanning strength, the more intense the cross-linking reaction, and the shorter the lateral stacking distance between collagen molecules. Based on this finding, the applicant defines the tanning strength of leather cultural relic samples as the degree of reduction in the lateral stacking distance between collagen molecules. The greater the reduction, the stronger the tanning strength. This method is not only simple to operate, but also a non-destructive testing technology, effectively overcoming the shortcomings of existing leather tanning strength testing technology.

[0022] refer to Figure 1 The present invention provides a method for determining the tanning strength of leather artifacts, wherein the determination steps are as follows:

[0023] The test obtained the synchrotron radiation light source wide-angle X-ray one-dimensional diffraction pattern of the leather artifact sample; the moisture content of the sample was 5%-10%;

[0024] Calculating the lateral stacking distance between sample collagen molecules according to the wide-angle X-ray one-dimensional diffraction pattern of the synchrotron radiation light source;

[0025] The tanning strength of the sample was calculated based on the lateral stacking distance using the formula: S = (1.30-D) / 1.30 × 100%; wherein S is the tanning strength, D is the lateral stacking distance, and 1.30 is the standard lateral stacking distance between untanned skin collagen molecules, expressed in nm.

[0026] Since high water content increases background scattering, reduces the overall electron density of the leather cultural relic sample, and affects the reliability of the data, the tanning strength of the leather cultural relic cannot be accurately quantified; meanwhile, the presence of bound water in the leather makes its water content cannot be lower than 5%, therefore, in the embodiment of the present application, the water content of the leather cultural relic sample is 5%-10% so as to ensure the accuracy of the detection result.

[0027] Based on the above theory, the present application is suitable for the determination of the tanning strength of all leather cultural relics with water content of 5%-10%. For example, the currently found leather cultural relics include aluminum tanned leather cultural relics, iron tanned leather cultural relics, smoked tanned leather cultural relics, oil tanned leather cultural relics, nitre faced tanned leather cultural relics, nitre tanned leather cultural relics, parchment cultural relics, and shadow play cultural relics; the sample form of the leather cultural relics can be in the shape of leather piece, leather residue and leather particle for easy determination.

[0028] It should be noted that the lateral stacking distance refers to the lateral stacking distance between collagen molecules, and the lateral stacking distance between molecules has been realized by the synchrotron radiation light source wide-angle X-ray one-dimensional diffraction spectrum in the prior art, and the present application also uses the calculation formula of the prior art to calculate. Specifically: D=2 π / q;wherein q is the horizontal coordinate value of the characteristic peak representing the distance between collagen molecules in the one-dimensional spectrum, unit nm -1 .

[0029] In the embodiment of the present application, the distance between the sample and the detector can be selected by a person skilled in the art according to the X-ray energy of the synchrotron radiation light source wide-angle X-ray scattering experimental station and the effective area of the detector, and under this condition, the leather should obtain the characteristic peak of the lateral stacking distance between collagen molecules through the detector. For example, the distance between the sample and the detector can be set to 30-50 cm.

[0030] In the embodiment of the present application, the test time of the sample and the setting of the X-ray energy can be selected by a person skilled in the art according to the actual thickness of the sample, as long as the characteristic peak of the lateral stacking distance between collagen molecules of the sample can be obtained through the detector. For example, the test time can be set to 0.1-2s, and the energy of the X-ray can be set to 8-15 keV.

[0031] In order to make the technical scheme of the present application clearer, the determination method of the tanning strength of the leather cultural relic is described in detail through a plurality of specific examples and comparative examples.

[0032] In the embodiment of the present application, the synchrotron radiation light source wide-angle X-ray scattering experiment is completed in the Shanghai synchrotron radiation wide-angle X-ray scattering experimental station, and the device model used is PILATUS 1M detector.

[0033] Due to the scarcity of leather artifact samples, ancient leather simulation samples were used in the comparative examples and examples. The preparation methods of different simulation samples are as follows:

[0034] Ancient aluminum-tanned leather simulation sample: In ancient Chinese chemistry, "alum" was often used to refer to metal sulfates. Alum is a common natural mineral with a long history and is widely used in leathermaking. The aluminum salt in alum can react with the carboxyl groups of skin collagen to achieve chemical crosslinking. Therefore, aluminum sulfate was used as the aluminum tanning agent in the tanning process. Sulfonated rapeseed oil, sulfated castor oil, and hot water were mixed and stirred in a mass ratio of 2:1:9 to form an emulsion. This was evenly applied to the flesh side of the tanned leather. After standing, drying on a stretcher, and vibration softening, the ancient aluminum-tanned leather simulation sample was produced.

[0035] Ancient oil-tanned leather simulant: Oil tanning is one of the oldest tanning methods. Ancient humans first used natural oils, such as pig, cattle, and sheep brains and fat, fish oil, or vegetable oils, to tan leather, relying on manual kneading. Therefore, highly unsaturated fish oil was used for the tanning process. The treated leather samples were oxidized at 40°C and 90%-100% relative humidity for four days. After alkali washing, hanging and air-drying, and hand-stretching, tumbling for two hours, and oscillating and stretching three times, the ancient oil-tanned leather simulant was produced.

[0036] Ancient iron-tanned leather simulation sample: The tanning agent used in iron tanning may be derived from the mineral chalcanthite. The main component of natural chalcanthite is KFe3(SO4)2(OH)6, and some chalcanthite is Fe3(SO4)2·9H2O formed by weathering and oxidation of natural green vitriol. The iron complex reacts with the carboxyl groups of collagen to form chemical crosslinks between the collagen in the skin. Therefore, when developing the iron tanning retro process, iron sulfate was used as the iron tanning agent for tanning. The tanned leather was emulsified with 10% sulfonated rapeseed oil and 5% sulfated castor oil, based on the weight of the tanned leather. After hanging and drying, tumbling, and other processes, the ancient iron-tanned leather simulation sample was produced.

[0037] Ancient smoke-tanned leather simulation sample: In ancient times, to prolong the storage life of animal hides and prevent them from rotting, the ancients discovered that smoke-fuming could prevent their deterioration. Volatile aldehydes and phenols in smoke can bind to hide collagen, producing a tanning effect. This is the origin of smoke tanning (aldehyde tanning). Since firewood is primarily composed of lignocellulose, its pyrolysis products, furfural and guaiacol, can simulate the volatile small molecules in smoke. Therefore, furfural and guaiacol are used as smoke tanning agents in the tanning process. Sulfonated rapeseed oil, sulfated castor oil, and hot water are mixed in a mass ratio of 2:1:9 to form an emulsion. This emulsion is then evenly applied to the flesh side of the tanned leather. After standing, drying on a stretcher, and vibration softening, the ancient smoke-tanned leather simulation sample is produced.

[0038] Ancient nitre surface tanning leather simulation sample: The earliest use of mirabilite (Na2SO4·10H2O) in history of China can be traced back to the appearance of the word "nitre" in the Zhuan script in the Warring States Period. Mirabilite is an important chemical product in ancient tanning, and the nitre surface tanning method using mirabilite and flour is one of the traditional tanning processes in China, which has the advantages of convenient availability of raw materials and simple tanning method. Therefore, mirabilite and starch are used as the nitre surface tanning agent for tanning process, and sulfonated rapeseed oil, sulfated castor oil and hot water are mixed and stirred in a mass ratio of 2:1:9 to form an emulsion, which is evenly applied to the flesh side of the tanned leather. After standing, drying on the stretching board and softening treatment, an ancient iron tanned leather simulation sample is prepared.

[0039] In the specific embodiments and comparative examples of the present application, the determination method of the shrinkage temperature of the ancient leather simulation sample is as follows:

[0040] The shrinkage temperature of the ancient leather simulation sample is determined by using a MSW-YD4 type digital leather shrinkage temperature tester.

[0041] The present application designs 8 examples and 8 comparative examples. In these examples, the moisture content of the ancient leather simulation sample is strictly controlled between 5% and 10% by drying method; while in the comparative examples, the moisture content of the ancient leather simulation sample exceeds 10% by constant temperature and humidity adjustment. Since it is known in the art that the tanning strength is positively correlated with the shrinkage temperature of the leather, the accuracy of the tanning strength measurement result can be reflected by the change relationship between the tanning strength and the shrinkage temperature determined in each of the examples and the comparative examples.

[0042] Example 1

[0043] The synchrotron radiation light source wide-angle X-ray one-dimensional diffraction pattern of the ancient nitre surface tanning simulation sample (leather piece) with a moisture content of 6% is obtained by testing, the X-ray energy is 15 keV, the distance between the sample and the Pilatus 1MF detector is 50 cm, and the exposure time is 1s. The lateral packing distance between collagen molecules of the ancient nitre surface tanning simulation sample is calculated using the formula D=2 π / q. The tanning strength of the ancient nitre surface tanning simulation sample is calculated using the formula S=(1.30-D) / 1.30×100%.

[0044] It is determined that the lateral packing distance between collagen molecules of the ancient nitre surface tanning simulation sample with a moisture content of 5% in this embodiment is 1.25 nm, and the tanning strength is 3.85%. The shrinkage temperature of the sample is detected, and the results are shown in Table 1.

[0045] Comparative Example 1

[0046] Comparative Example 1 differs from Example 1 in that the moisture content of the simulated ancient nitre-tanned leather sample (leather block) was 30%. Measurements revealed a lateral stacking distance between collagen molecules of 1.18 nm and a tanning strength of 9.23%. Shrinkage temperature testing of this sample was performed, and the results are shown in Table 1.

[0047] Example 2

[0048] A synchrotron radiation wide-angle X-ray one-dimensional diffraction pattern was obtained for an 8% moisture simulated ancient aluminum-tanned leather sample. The X-ray energy was 15 keV, the sample-to-Pilatus 1MF detector distance was 35 cm, and the exposure time was 0.1 s. The lateral stacking distance between collagen molecules in the simulated aluminum-tanned sample was calculated using the formula D = 2π / q. The tanning strength of the simulated aluminum-tanned sample was calculated using the formula S = (1.30-D) / 1.30 × 100%.

[0049] The lateral stacking distance between collagen molecules in the simulated ancient aluminum tanning sample with a moisture content of 8% was measured to be 1.22 nm, and the tanning strength was 6.15%. The shrinkage temperature of this sample was also tested, and the results are shown in Table 1.

[0050] Comparative Example 2

[0051] Comparative Example 2 differs from Example 2 in that the moisture content of the simulated ancient aluminum-tanned leather sample (leather block) was 50%. Measurements revealed a lateral stacking distance between collagen molecules of 1.19 nm and a tanning intensity of 8.46%. Shrinkage temperature testing was also conducted on this sample, and the results are shown in Table 1.

[0052] Example 3

[0053] A synchrotron radiation wide-angle X-ray one-dimensional diffraction pattern was obtained for an 8% moisture simulated ancient aluminum-tanned leather sample. The X-ray energy was 10 keV, the sample-to-Pilatus 1MF detector distance was 30 cm, and the exposure time was 0.1 s. The lateral stacking distance between collagen molecules in the simulated aluminum-tanned sample was calculated using the formula D = 2π / q. The tanning strength of the simulated aluminum-tanned sample was calculated using the formula S = (1.30-D) / 1.30 × 100%.

[0054] The lateral stacking distance between collagen molecules in the simulated ancient aluminum tanning sample with a moisture content of 8% was measured to be 1.18 nm, and the tanning strength was 9.23%. The shrinkage temperature of this sample was also tested, and the results are shown in Table 1.

[0055] Comparative Example 3

[0056] Comparative Example 3 differs from Example 3 in that the moisture content of the simulated ancient aluminum-tanned leather sample (leather block) was 50%. Measurements revealed a lateral stacking distance between collagen molecules of 1.22 nm and a tanning intensity of 6.15%. Shrinkage temperature testing was also conducted on this sample, with the results shown in Table 1.

[0057] Example 4

[0058] A synchrotron radiation wide-angle X-ray one-dimensional diffraction pattern was obtained for an ancient smoke-tanned simulated sample (leather particles) with a moisture content of 5%. The X-ray energy was 15 keV, the sample-to-Pilatus 1MF detector distance was 40 cm, and the exposure time was 1 s. The lateral stacking distance between collagen molecules in the ancient smoke-tanned simulated sample was calculated using the formula D = 2π / q. The tanning strength of the ancient smoke-tanned simulated sample was calculated using the formula S = (1.30-D) / 1.30×100%.

[0059] The lateral stacking distance between collagen molecules in the simulated ancient smoke-tanned sample with a moisture content of 5% was measured to be 1.15 nm, and the tanning intensity was 11.54%. The sample was also tested for shrinkage temperature, and the results are shown in Table 1.

[0060] Comparative Example 4

[0061] Compared to Example 4, Comparative Example 4 differs in that the moisture content of the simulated ancient smoke-tanned leather sample (leather particles) is 30%. Measurements show that the lateral stacking distance between collagen molecules is 1.20 nm, and the tanning intensity is 7.69%. Shrinkage temperature testing of this sample is also conducted, and the results are shown in Table 1.

[0062] Example 5

[0063] A synchrotron radiation wide-angle X-ray one-dimensional diffraction pattern was obtained for an 8% moisture simulated sample (leather block) of ancient aluminum tanning. The X-ray energy was 8 keV, the sample-to-Pilatus 1MF detector distance was 35 cm, and the exposure time was 2 s. The lateral stacking distance between collagen molecules in the simulated sample was calculated using the formula D = 2π / q. The tanning strength of the simulated sample was calculated using the formula S = (1.30-D) / 1.30×100%.

[0064] The lateral stacking distance between collagen molecules in the simulated ancient aluminum tanning sample with a moisture content of 8% was measured to be 1.11 nm, and the tanning strength was 14.62%. The sample was also tested for shrinkage temperature, and the results are shown in Table 1.

[0065] Comparative Example 5

[0066] Compared to Example 5, Comparative Example 5 differs in that the moisture content of the simulated ancient aluminum tanning sample (leather block) was 50%. Measurements revealed a lateral stacking distance between collagen molecules of 1.21 nm and a tanning strength of 6.92%. Shrinkage temperature testing was also conducted on this sample, and the results are shown in Table 1.

[0067] Example 6

[0068] A synchrotron radiation wide-angle X-ray one-dimensional diffraction pattern was obtained for an ancient oil-tanning simulated sample (leather residue) with a moisture content of 5%. The X-ray energy was 10 keV, the sample-to-detector distance was 50 cm, and the exposure time was 1 s. The lateral stacking distance between collagen molecules in the ancient oil-tanning simulated sample was calculated using the formula D = 2π / q. The tanning intensity of the ancient oil-tanning simulated sample was calculated using the formula S = (1.30-D) / 1.30×100%.

[0069] The lateral stacking distance between collagen molecules in the simulated ancient oil tanning sample with a moisture content of 5% was measured to be 1.10 nm, and the tanning intensity was 15.39%. The shrinkage temperature of this sample was also tested, and the results are shown in Table 1.

[0070] Comparative Example 6

[0071] Compared to Example 6, Comparative Example 6 differs in that the moisture content of the simulated ancient oil-tanned leather residue sample (leather residue) is 65%. Measurements show that the lateral stacking distance between collagen molecules is 1.22 nm, and the tanning intensity is 6.15%. Shrinkage temperature testing of this sample is also conducted, and the results are shown in Table 1.

[0072] Example 7

[0073] A synchrotron radiation wide-angle X-ray one-dimensional diffraction pattern was obtained for an 8% moisture simulated sample (leather block) of ancient aluminum tanning. The X-ray energy was 10 keV, the sample-to-Pilatus 1MF detector distance was 50 cm, and the exposure time was 2 s. The lateral stacking distance between collagen molecules in the simulated sample was calculated using the formula D = 2π / q. The tanning strength of the simulated sample was calculated using the formula S = (1.30-D) / 1.30×100%.

[0074] The lateral stacking distance between collagen molecules in the simulated ancient aluminum tanning sample with a moisture content of 8% was measured to be 1.08 nm, and the tanning intensity was 16.92%. The shrinkage temperature of this sample was also tested, and the results are shown in Table 1.

[0075] Comparative Example 7

[0076] Comparative Example 7 differs from Example 7 in that the moisture content of the simulated ancient aluminum-tanned leather sample (leather block) was 50%. Measurements revealed a lateral stacking distance between collagen molecules of 1.20 nm and a tanning strength of 7.69%. Shrinkage temperature testing was also conducted on this sample, and the results are shown in Table 1.

[0077] Example 8

[0078] A synchrotron radiation wide-angle X-ray one-dimensional diffraction pattern was obtained for an ancient iron-tanned simulated sample (leather residue) with a moisture content of 10%. The X-ray energy was 10 keV, the sample-to-Pilatus 1MF detector distance was 40 cm, and the exposure time was 0.1 s. The lateral stacking distance between collagen molecules in the ancient iron-tanned simulated sample was calculated using the formula D = 2π / q. The tanning strength of the ancient iron-tanned simulated sample was calculated using the formula S = (1.30-D) / 1.30×100%.

[0079] The lateral stacking distance between collagen molecules in the simulated ancient iron tanning sample with a moisture content of 10% was measured to be 1.05 nm, and the tanning strength was 19.23%. The shrinkage temperature of this sample was tested, and the results are shown in Table 1.

[0080] Comparative Example 8

[0081] Comparative Example 8 differs from Example 8 in that the moisture content of the simulated ancient iron tanning sample (leather residue) is 40%. Measurements show that the lateral stacking distance between collagen molecules is 1.18 nm, and the tanning intensity is 9.23%. Shrinkage temperature testing of this sample is also conducted, and the results are shown in Table 1.

[0082] Table 1

[0083] .

[0084] Analysis of the data in Table 1 shows that within the moisture content range of 5%-10%, the tanning strength and shrinkage temperature of the different ancient leather simulation samples in Examples 1-8 show a positive correlation. In contrast, no correlation was observed between the tanning strength and shrinkage temperature of the different ancient leather simulation samples in Comparative Examples 1-8. This is mainly because the moisture content in the comparative leathers exceeded 10%, resulting in increased background scattering, reducing the overall electron density of the samples, and thus affecting the reliability of the data, making it impossible to accurately quantify the tanning strength of the samples. Therefore, the tanning strength determination method of the present invention is applicable to leather artifacts with a moisture content of 5%-10%.

[0085] Analysis of the above examples and comparative examples clearly demonstrates the efficiency and practicality of this method for determining the tanning strength of leather artifacts. Furthermore, its completely non-destructive testing method is unattainable with existing technologies. This method utilizes synchrotron radiation X-ray scattering technology to determine the tanning strength of leather artifacts. Compared to existing technologies, this method not only effectively addresses the issues of sample scarcity and irregular morphology, but also significantly improves the accuracy and reliability of the test, fully meeting the requirements of non-destructive testing for artifact identification.

[0086] The embodiments described above are some embodiments of the present invention, rather than all embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

Claims

1. A method for determining the tanning strength of leather artifacts, characterized in that: The measurement steps are: The test obtained the synchrotron radiation light source wide-angle X-ray one-dimensional diffraction pattern of the leather artifact sample; the moisture content of the sample was 5%-10%; Calculating the lateral stacking distance between sample collagen molecules according to the wide-angle X-ray one-dimensional diffraction pattern of the synchrotron radiation light source; The tanning strength of the sample was calculated based on the lateral stacking distance using the formula: S = (1.30-D) / 1.30 × 100%; wherein S is the tanning strength, D is the lateral stacking distance, and 1.30 is the standard lateral stacking distance between untanned skin collagen molecules, expressed in nm.

2. The method for measuring the tanning strength of leather cultural relics as claimed in claim 1, wherein The distance between the sample and the detector during the wide-angle X-ray scattering test at the synchrotron radiation source is 30-50 cm.

3. The method for measuring the tanning strength of leather cultural relics as claimed in claim 1, wherein The test time of wide-angle X-ray scattering at the synchrotron radiation source is 0.1-2 s.

4. The method for measuring the tanning strength of leather cultural relics as claimed in claim 1, wherein The energy range of wide-angle X-ray scattering at synchrotron radiation sources is 8-15 keV.

5. The method for measuring the tanning strength of leather cultural relics as claimed in claim 1, wherein The leather artifact samples include any one of aluminum tanned leather artifacts, iron tanned leather artifacts, smoked tanned leather artifacts, oil tanned leather artifacts, nitrated leather artifacts, nitrate tanned leather artifacts, parchment artifacts, and shadow puppet artifacts.

6. The method for measuring the tanning strength of leather artifacts as claimed in claim 1, wherein: The leather artifact sample comprises any one of leather pieces, leather residues and leather particles.

7. The method for measuring the tanning strength of leather artifacts as claimed in claim 1, wherein: The calculation formula for the lateral stacking distance is: D = 2π / q; where q is the horizontal coordinate value of the characteristic peak representing the distance between collagen molecules in the one-dimensional spectrum, and the unit is nm. -1 .

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