Nondestructive evaluation method for sizing degree of handmade paper

Abstract

The invention relates to a nondestructive evaluation method for the sizing degree of handmade paper. The method comprises the following steps: releasing liquid drops by using a microsyringe, accurately controlling the volume of the liquid drops, and recording the whole diffusion process of the liquid drops after the liquid drops are in contact with a paper surface by using high-definition camera equipment. The liquid drop contact and diffusion stop time is recorded through video editing software, the longitudinal and transverse maximum diffusion distance is measured by using a graduated scale, and the diffusion area is estimated. And in combination with the diffusion time and area, calculating the logarithmic sizing degree through a logarithmic sizing degree formula, and recording experimental data for evaluating the performance of the paper. Compared with the prior art, the invention provides an innovative solution aiming at the defects of the existing national standard on the paper sizing degree detection method, especially the problems that the paper sizing degree detection method is not suitable for the traditional handmade paper in China and the nondestructive testing of ancient book leaves cannot be realized. According to the method, the blank of paper sizing degree research in the field of paper literature restoration is effectively filled up, and important technical support is provided for ancient book restoration and paper cultural relic protection.

Description

Technical Field

[0001] The invention relates to the technical field of paper quality evaluation, in particular to a non-destructive evaluation method for the sizing degree of handmade paper. Background Art

[0002] Paper documents are the carriers of human thought and civilization. After hundreds or even thousands of years of reading and inheritance, many of them have been damaged by insects, mold, ash, and aging. Restoration techniques to protect these precious documents have become a professional technology. In recent years, there are nearly 100 types of paper available on the market that can be used for document restoration, most of which are handmade papers. Different papers differ in terms of fiber composition, color, basis weight, thickness, tightness, pH, and expansion ratio. In order to select suitable restoration materials, common auxiliary tests include paper thickness, color, pH, and expansion ratio.

[0003] In document restoration, the degree of paper sizing has important reference value for the verification of papermaking technology and the formulation of document restoration strategies. The national standard test methods for sizing degree and water absorption are rarely used in handmade paper and document restoration, mainly because most test methods are destructive. In addition, due to its special fiber structure and production process, handmade paper usually has the characteristics of strong water absorption and uneven thickness, and the data repeatability is poor, which limits the application of sizing degree and water absorption test methods. For example, the ink line drawing method (national standard GB / T 460-2008) requires standard ink to draw lines on paper, the liquid penetration method (national standard GB / T 5405-2002) requires the use of ferric chloride and ammonium thiocyanate solution, and the immersion method (national standard GB / T 461.3-2005) and water floating method require cutting paper samples and manual counting. The Cobb method (national standard GB / T 1540-2002) and contact angle method also require cutting samples, and the equipment is expensive and inconvenient to operate, which is not suitable for on-site operation.

[0004] Therefore, it is necessary to develop a convenient and low-loss determination method suitable for handmade paper. Summary of the invention

[0005] The invention aims to provide a non-destructive evaluation method for the sizing degree of handmade paper, which is fast, convenient and non-destructive.

[0006] The object of the present invention can be achieved by the following technical scheme: A non-destructive evaluation method for the sizing degree of handmade paper comprises the following steps:

[0007] (1) Dropping the test liquid on the paper test sample, recording the diffusion process of the test liquid on the paper test sample, and calculating the diffusion time T;

[0008] (2) Measure the maximum lateral distance L of the test liquid diffusion C and the maximum longitudinal distance LM ;

[0009] (3) Calculate the diffusion area A according to the following formula:

[0010]

[0011] (4) Calculate the logarithmic sizing degree Log S according to the following formula and round it off:

[0012]

[0013] The detection liquid includes deionized water.

[0014] Preferably, the unit of T is s, and the units of L C and L M are cm.

[0015] More preferably, the units of L C and L M are accurate to one decimal place after the decimal point.

[0016] Preferably, the paper test sample is flat, free of defects and has a uniform texture.

[0017] Preferably, adjust the placement direction of the paper test sample to judge the horizontal and vertical directions.

[0018] More preferably, the method for judging the horizontal and vertical directions is the national standard "GB / T 452.1 - 2002 Determination of the Machine and Cross Directions of Paper and Board".

[0019] Even more preferably, the method for judging the horizontal and vertical directions is the fiber orientation identification method.

[0020] Preferably, the paper test sample is blank, without handwriting and obvious impurities.

[0021] Preferably, the size of the paper test sample is not less than 30 mm × 30 mm.

[0022] Preferably, make the paper test sample hang naturally in the air to avoid the presence of water-absorbing substances or flat surfaces interfering with the natural diffusion of the liquid droplets below the test area.

[0023] The present invention can ensure the stability of the measurement results by selecting the paper test sample.

[0024] Preferably, accurately suck deionized water with a 5-μL microinjector or a micropipette with the same volume and precision, and touch the paper surface of the paper test sample with the liquid droplet in a gentle contact manner.

[0025] In the present invention, the deionized water droplet touches the paper surface gently, and actions such as "dotting", "dipping", and "scraping" with external forces cannot be used.

[0026] Further preferably, after sucking up deionized water, gently wipe the outer side of the syringe needle with a clean absorbent paper towel or filter paper to remove excess moisture.

[0027] Further preferably, after sucking up deionized water, expel the air bubbles and excess liquid in the syringe or pipette gun to ensure that the liquid is 5 microliters.

[0028] Preferably, the water temperature of the deionized water is maintained at 23°C ± 2°C.

[0029] Preferably, drop the detection liquid onto the paper detection sample, use a high-definition camera device to record the diffusion process of the detection liquid, analyze frame by frame through video editing software, mark the initial time t1 when the detection liquid contacts the paper surface of the paper detection sample and the diffusion stop time t2, and calculate the diffusion time according to the following formula:

[0030] T = t2 - t1.

[0031] Further preferably, t1 and t2 are accurate to two decimal places.

[0032] Further preferably, the high-definition camera device is 15 - 30 cm away from the paper surface, and the frame rate is set to 60 - 120 fps.

[0033] Further preferably, the shooting angle of the high-definition camera device is a side oblique shooting, forming an angle of 45° - 60° with the paper surface.

[0034] Further preferably, the detection liquid is kept at a distance of 1 - 2 mm from the surface of the paper detection sample. After ensuring that the video image is clear, gently touch the paper surface to make the liquid droplet contact the paper surface, avoiding applying other external forces.

[0035] Further preferably, the high-definition camera device has a macro mode and has functions of automatic focusing and adjusting light to ensure that the video picture is clear and stable.

[0036] Preferably, use a transparent scale to measure the maximum lateral distance L of the detection liquid diffusion C and the maximum longitudinal distance L M .

[0037] Further preferably, the maximum range of the transparent scale is not less than 5 cm, and the accuracy is 1 mm.

[0038] Preferably, the measurement of the diffusion distance of the detection liquid is carried out within 1 minute after the detection liquid is completely diffused.

[0039] In the present invention, the measurement of the diffusion distance should be carried out within 1 minute after the water droplet is completely diffused.

[0040] Preferably, steps (1)-(2) are repeated using multiple paper test samples of the same material or multiple positions of the same paper test sample to obtain the average diffusion time T, the average maximum lateral distance L C and the average maximum longitudinal distance L M , and then steps (3)-(4) are carried out to obtain the average logarithmic sizing degree Log S, and it is rounded off.

[0041] Preferably, steps (1)-(4) are repeated using multiple paper test samples of the same material or multiple positions of the same paper test sample to obtain the average logarithmic sizing degree Log S, and it is rounded off.

[0042] Preferably, the rounded logarithmic sizing degree Log S is used to evaluate the sizing degree of the paper. The larger Log S is, the higher the sizing degree of the handmade paper indicates.

[0043] Preferably, the method is carried out in a stable natural environment.

[0044] More preferably, the method is experimented under standard atmospheric conditions, with a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5%.

[0045] Preferably, the handmade paper includes bamboo paper, rice paper, and leather paper.

[0046] A system for realizing a method for non-destructive evaluation of the sizing degree of handmade paper, comprising:

[0047] A microinjector or a micropipette for precisely controlling the droplet volume;

[0048] A high-definition camera device for recording the water droplet diffusion process;

[0049] Video editing software for frame-by-frame analysis of the water droplet diffusion time;

[0050] A transparent scale for measuring the diffusion distance

[0051] A logarithmic sizing degree calculation method for evaluating the sizing degree of handmade paper.

[0052] The present invention proposes an improved water drop diffusion method. By using tools such as a microinjector, a scale, and video editing software, while ensuring the measurement accuracy, the measurement difficulty is significantly reduced, and the impact on the original is greatly reduced. This method is particularly suitable for the sizing degree determination of precious paper documents and most papers, can be carried out quickly and simply at the restoration site, provides more accurate reference data for the restoration work, and has important application value for the restoration of ancient books, paintings, and the protection of precious documents.

[0053] The present invention uses a micro-syringe to precisely control the water droplet volume and high-definition video shooting technology to fully record the droplet diffusion process. At the same time, high-definition video analysis technology is adopted, which improves the detection accuracy compared with the traditional stopwatch timing. The diffusion area is estimated through the maximum longitudinal and transverse diffusion distances, which is simple and fast, without the need for expensive equipment, and the measurement accuracy can meet the requirements of experimental analysis. The formula for calculating the rounded logarithm sizing degree is used to evaluate handmade paper, with good repeatability and applicability to most handmade papers. The present invention provides a fast, convenient, and non-destructive sizing degree detection method, which is applicable to the performance evaluation of various traditional handmade papers.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] 1. The present invention can detect the sizing degree of paper, and is optimized for the characteristics of strong water absorption and light texture of handmade paper, making up for the defects that national standards such as the ink line drawing method (National Standard GB / T 460-2008) and the liquid penetration method (National Standard GB / T5405-2002) are not applicable to Chinese traditional handmade papers. It is especially suitable for the performance detection of precious papers in the restoration of ancient books, calligraphy and paintings, and traditional craft research.

[0056] 2. The present invention uses a micro-syringe to accurately control the volume of the liquid droplet, improving the detection accuracy and minimizing the impact on the paper as much as possible.

[0057] 3. The present invention selects a 5-μL micro-syringe or micropipette, and the formed liquid droplet cannot fall naturally, and the liquid droplet is close to an ellipse after diffusion, which is convenient for measurement operation.

[0058] 4. The present invention uses high-definition shooting equipment and video editing software to analyze frame by frame and accurately measure the liquid droplet diffusion time and range, solving the error problem of stopwatch timing, and is especially suitable for samples with fast water absorption speed.

[0059] 5. The present invention quickly estimates the diffusion area by measuring the maximum longitudinal and transverse diffusion distances of the liquid droplet before it dries.

[0060] 6. By analyzing the maximum longitudinal and transverse diffusion distances of the liquid droplet, the present invention can further confirm the longitudinal and transverse directions and differences of the paper.

[0061] 7. The present invention combines the liquid droplet absorption time (t) and the diffusion area (A), quantifies the sizing degree with a mathematical formula, and performs operations such as taking logarithms and rounding, making the data concise and having good repeatability, which is convenient for comparison and analysis of different samples.

[0062] 8. The present invention solves the drawbacks of traditional detection methods that require sample cutting, expensive instruments or the use of chemical reagents, and provides important technical support for the restoration and protection of precious documents.

[0063] 9. The method of the present invention is simple, highly operable, time-consuming short, and low-cost. In addition to providing reference for the restoration of paper documents, it is further extended to scenarios such as the research of traditional paper technology and product quality control, and has significant technical promotion value.

[0064] 10. The present invention provides a sizing degree detection method for handmade paper based on the micro-droplet diffusion method, which is especially applicable to traditional handmade paper with strong water absorption and thin texture. This method is applicable to fields such as the restoration of ancient books and paintings, the research of paper technology, and the quality control of paper, and has broad application prospects in the field of the restoration of paper cultural relics and the evaluation of paper quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a schematic diagram of the operation of dripping water with a microinjector in Example 1 of the present invention;

[0066] Figure 2 It is a schematic diagram of a water droplet on the surface of the paper in the present invention;

[0067] Figure 3 On the left is a schematic diagram of the droplet not being completely absorbed, and on the right is a schematic diagram of the droplet being completely absorbed;

[0068] In the figure: 1 - microinjector, 2 - 5 μL of deionized water, 3 - backing plate, 41 - droplet diffusing, 42 - droplet diffusion completed. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0069] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0070] A non-destructive evaluation method for the sizing degree of traditional handmade paper includes the following steps:

[0071] (1) Select a suitable area: For the sample to be tested, a flat, flawless, and uniform-textured blank area can be selected as the test sample, avoiding the aged and discolored areas at the four edges to ensure that it represents the overall performance of the paper.

[0072] (2) Adjust the direction of the paper: In order to quickly measure the maximum diffusion distance in the longitudinal and transverse directions, first determine the longitudinal and transverse directions of the paper, and keep the paper sample horizontal in the transverse direction and vertical in the longitudinal direction.

[0073] (3) Measurement preparation: Place a bright red plastic backing plate under the paper, which can clearly observe the droplet diffusion situation, facilitate the completion of the measurement, and at the same time prevent the lower layer of the paper from absorbing water and interfering with the measurement result.

[0074] (4) Dripping Preparation: Use a 5-μL micro syringe to aspirate deionized water as the standard liquid for droplet detection.

[0075] (5) Video Shooting: Use a high-definition imaging device (such as a smartphone or camera) to record the entire process of the droplet spreading after contacting the paper surface.

[0076] (6) Dripping Operation: Push out the 5 μL of deionized water in the micro syringe to make the droplet circular and keep it in a natural state without dripping. Keep a distance of about 1 - 2 mm between the droplet and the surface of the test sample. After ensuring that the video image is clear, gently touch the paper surface to make the droplet contact the paper, avoiding applying other external forces.

[0077] (7) Measurement of Spreading Area: Wait until there are no visible droplets on the paper surface. Use a scale to measure the final spreading area of the droplet diffusion, and record the maximum horizontal spreading distance (L C ) and the maximum vertical spreading distance (L M ).

[0078] (8) On the same test sample, select four other positions according to the above requirements and repeat the above operations.

[0079] (9) Analysis of Spreading Time: Analyze frame by frame through video editing software, mark the initial time point (t1) when the droplet contacts the paper surface and the stop time point (t2) of the spreading, calculate the spreading time and its average value (T). The formula for the spreading time is as follows:

[0080] T = t2 - t1

[0081] (10) Estimation of Spreading Area: Estimate the spreading area (A) according to the following formula:

[0082]

[0083] And calculate the average value of the spreading area (A) of this sample.

[0084] (11) Calculation of Logarithmic Sizing Degree: Use the spreading time T and the spreading area A to calculate the logarithmic sizing degree (Log S) and round it. The formula for Log S is as follows:

[0085]

[0086] As a preferred technical solution, the test sample described in step (1) can be blank paper or literature. Each selected specimen is not less than 30 mm * 30 mm to avoid the influence of writing or printing ink on the measurement of the sizing degree of the paper.

[0087] As a preferred technical solution, for the method of judging the longitudinal and transverse directions of the sample to be tested in step (2), refer to the national standard "GB / T 452.1-2002 Determination of the longitudinal and transverse directions of paper and paperboard". For precious documents that require non-destructive testing, only the fiber orientation identification method can be used.

[0088] As a preferred technical solution, after using a micropipette to aspirate deionized water in step (3), gently wipe the outer side of the pipette needle with a clean absorbent tissue or filter paper to remove excess moisture. This operation can avoid inaccurate injection volume caused by residual liquid on the outer side of the needle.

[0089] As a preferred technical solution, after using a micropipette to aspirate deionized water in step (3), hold the tip of the pipette upward and expel the air bubbles and excess liquid in the needle to ensure that the liquid volume in the needle is consistent.

[0090] As a preferred technical solution, the high-definition camera device in step (4) should use a bracket, and the shooting angle should be a side oblique shot, forming an angle of 45° - 60° with the paper surface, so as to clearly capture the contact moment and diffusion process of the liquid droplet.

[0091] As a preferred technical solution, the high-definition camera device in step (4) is about 15 - 30 cm away from the paper surface to ensure that the liquid droplet diffusion area is completely within the camera's field of view. The light in the shooting environment should be uniform and free from reflective interference to ensure clear and stable video images.

[0092] As a preferred technical solution, it is recommended to select the microscopic mode for the high-definition camera device in step (4), and set the frame rate to 60 - 120 fps to accurately record the time change of the liquid droplet diffusion.

[0093] As a preferred technical solution, the operation in step (5) should be carried out in a stable natural environment to avoid external interference affecting the shape and contact effect of the liquid droplet.

[0094] As a preferred technical solution, the operation in step (6) should be carried out within 1 minute after the liquid droplet has completely diffused. The scale should be a transparent scale with a maximum range of not less than 5 cm, and the recommended accuracy is 1 mm.

[0095] As a preferred technical solution, the method of analyzing the diffusion time in step (8) is applicable to samples with good water absorption, especially those with a diffusion time less than 30 s. For samples with a long diffusion time exceeding 5 minutes, a stopwatch can also be used for timing.

[0096] As a preferred technical solution, after calculating the sizing degree using the diffusion time T and diffusion area A of the same point in step (9), then calculate the average value of the sizing degrees of ten points on the sample to avoid errors caused by the unevenness of handmade paper.

[0097] As a preferred technical solution, t1, t2, L C and L M are accurate to two decimal places after the decimal point.

[0098] As a preferred technical solution, this method conducts experiments under standard atmospheric conditions, with a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5%.

[0099] As a preferred technical solution, the water temperature of the deionized water aspirated by the micro-syringe should be maintained at 23°C ± 1°C, and it can be controlled with the help of a thermometer and a daily heat preservation device.

[0100] Generally speaking, the present invention includes the following four steps: The first step is to select a flat and flawless paper area, confirm the longitudinal and transverse directions of the paper, and adjust the paper to be horizontal in the transverse direction to facilitate the subsequent rapid measurement of the maximum diffusion distances in different directions. The second step is to use a 5-μL micro-syringe to release the liquid droplet, precisely control the volume of the liquid droplet, and use a high-definition imaging device to record the entire process of the liquid droplet spreading after contacting the paper surface. The third step is data analysis: record the contact and diffusion stop times of the liquid droplet through video editing software, measure the maximum longitudinal and transverse diffusion distances with a scale, and estimate the diffusion area. The fourth step is the calculation of the logarithm sizing degree: combine the diffusion time and area, calculate the logarithm sizing degree through the logarithm sizing degree formula, and record the experimental data for evaluating the paper performance.

[0101] The following will be described in detail with specific embodiments.

[0102] Unless otherwise specified, the reagents, methods, instruments, and equipment used in the present invention are conventional reagents, methods, instruments, and equipment in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0103] Example 1

[0104] A detection method applicable to the sizing degree of rough-edge paper includes the following steps:

[0105] Keep the detection under standard atmospheric conditions, a temperature of 23 ± 2°C, and a relative humidity of 50% ± 5%. Use a thermometer to detect and maintain the water temperature of the deionized water for detection at 23 ± 2°C.

[0106] First, observe the watermarks of the rough-edge paper. Combine with the national standard "GB / T 452.1 - 2002 Determination of the longitudinal and transverse directions of paper and paperboard" to judge the longitudinal and transverse directions of the specimen, and keep the rough-edge paper horizontal in the transverse direction and vertical in the longitudinal direction.

[0107] Select rice paper that is smooth, flawless, and has a uniform blank area of no less than 30mm * 30mm as the detection point. Avoid the aged and discolored areas along the four edges. Place the red plastic backing plate 3 under the test area and adjust the smartphone with a stand to prepare for shooting from the side and at an angle.

[0108] As Figure 1 shown, use a microinjector 1 to accurately aspirate 5 μL of deionized water 2 as the droplet detection liquid, and slowly push it out. The droplet should remain round and not drip under natural conditions. When the droplet is about 1 - 2 mm away from the paper, confirm that the video image is clear and record the entire process from when the droplet touches the paper surface to when it completely spreads.

[0109] As Figure 2 shown, it is a schematic diagram of the initial state of the water droplet on the paper surface. After diffusion, as Figure 3 shown, on the left is a schematic diagram of the droplet not being completely absorbed, and on the right is a schematic diagram of the droplet being completely absorbed.

[0110] After finishing shooting, immediately use a ruler to measure the maximum horizontal diffusion distance (L C ) and the maximum vertical diffusion distance (L M ). Estimate the diffusion area A = π * (0.5 * L C * 0.5 * L M ). Through frame-by-frame analysis using video editing software, mark the initial time point (t1) when the droplet touches the paper surface and the diffusion stop time point (t2), calculate the diffusion time T, calculate the logarithm sizing degree (Log S) = Log(T / A), and round it. According to the above requirements, select four other positions on the rice paper and repeat the above operations, then calculate the average value.

[0111] This method has good repeatability. Under the conditions of room temperature 25°C, relative humidity 50%, and water temperature 21°C, when measuring the same kind of rice paper multiple times, the data is as follows:

[0112] Table 1: Detection results of the logarithm sizing degree of a kind of rice paper at the same temperature

[0113]

[0114] Note: round(Log S) represents taking the integer value of Log S by the rounding method.

[0115] Under the conditions of room temperature 25°C, relative humidity 50%, and water temperature 21 - 25°C, when measuring the same kind of rice paper multiple times, the data is as follows:

[0116] Table 2: Detection results of the logarithm sizing degree of a kind of rice paper at different temperatures

[0117]

[0118] Note: round(Log S) represents the integer value of Log S obtained by rounding according to the rounding method.

[0119] Example 2

[0120] Detection of the sizing degree of the paper of a copper mesh embossed letterpress printed book during the Republic of China period includes the following steps:

[0121] Keep the detection under standard atmospheric conditions, at a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5%. Use a water thermometer and a thermos cup to form a constant temperature water bath environment, and keep the deionized water temperature for droplet detection at 23 ± 2°C.

[0122] National standard "GB / T 452.1-2002 Determination of the grain direction of paper and board". Use the fiber orientation identification method to judge the longitudinal and transverse directions of the specimen, and keep the paper of the book leaf horizontal in the transverse direction and vertical in the longitudinal direction.

[0123] Select a flat and flawless, uniform blank area on the book leaf as the detection point, with an area of not less than 30mm * 30mm. Avoid the aged and discolored areas at the four edges. Place a red plastic backing plate under the test area, and adjust the smartphone with a stand to prepare for shooting from the side and obliquely.

[0124] Use a microinjector to accurately suck 5 microliters of deionized water as the droplet detection liquid. Slowly push it out so that the droplet remains round and does not drip under natural conditions. When the droplet is about 1 - 2 millimeters away from the paper, confirm that the video image is clear, and record the whole process from the droplet touching the paper surface to complete diffusion.

[0125] After finishing shooting, immediately use a scale to measure the maximum lateral diffusion distance (L C ) and the maximum longitudinal diffusion distance (L M ), and estimate the diffusion area A = π * (0.5 * L C * 0.5 * L M ).

[0126] Through frame-by-frame analysis using video editing software, mark the initial time point (t1) when the droplet touches the paper surface and the diffusion stop time point (t2), calculate the diffusion time (T) and the logarithmic sizing degree (Log S) = Log(T / A).

[0127] According to the above requirements, select four other positions on the book leaf, repeat the above operations, calculate the logarithmic sizing degree (LogS), and round it. The results are as follows in the table:

[0128] Table 3: Detection results of the logarithmic sizing degree of a copper mesh embossed letterpress printed book during the Republic of China period

[0129]

[0130] Example 3

[0131] The sizing degrees of several common traditional handmade papers (dyed mounting papers for covers, rice papers) were measured by the method used in the present invention and the ink line drawing method respectively. For the detection method of the ink line drawing method, in accordance with the national standard "Determination of Paper Sizing Degree" (GB / T 460–2008), the sizing degree results of the two methods are as follows in the table:

[0132] Table 4: Comparison of the sizing degree detection results of several common handmade papers by the method of the present invention and the ink line drawing method

[0133]

[0134] Example 4

[0135] The sizing degrees of various papers were measured by the method used in the present invention respectively, and the results are as follows in the table:

[0136] Table 5: Detection results of the sizing degrees of various papers by the method of the present invention

[0137]

[0138] The method of the present invention is conducive to quantitatively describing the sizing degree of handmade papers. After processing the sizing degree with a mathematical formula, the value of logarithmic sizing degree (Log S) is concise and has good repeatability, overcoming the drawbacks that the liquid diffusion is very sensitive to the environmental temperature and humidity and the unevenness of handmade papers, and is applicable to most handmade papers, including highly absorbent rice papers (raw rice papers), and various types of highly sized processed papers (such as cover papers), etc.

[0139] The method of the present invention helps to simply classify the sizing degrees of different types of handmade papers. The detection values of most low-sizing-degree handmade papers are 0 - 2, and those of medium-high-sizing-degree handmade papers are 3 - 5.

[0140] Aiming at the deficiencies in the detection method of paper sizing degree in the current national standard, especially the problems that it is not applicable to Chinese traditional handmade papers and cannot achieve non-destructive detection of ancient book leaves, the present invention proposes an innovative solution. The present invention effectively fills the gap in the research on paper sizing degree in the field of paper document restoration, and provides important technical support for ancient book restoration and the protection of paper cultural relics.

[0141] The above description of the embodiments is for the ordinary technical personnel in the technical field to understand and use the invention. Those skilled in the art can obviously make various modifications to these embodiments easily and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for non-destructive evaluation of the sizing degree of handmade paper, characterized in that, It includes the following steps: (1) Drop the detection liquid on the paper detection sample, record the diffusion process of the detection liquid on the paper detection sample to calculate the diffusion time T; (2) Measure the maximum lateral distance L of the diffusion of the detection liquid C and the maximum longitudinal distance L M ; (3) Calculate the diffusion area A according to the following formula: (4) Calculate the logarithm sizing degree Log S according to the following formula and round it up: The detection liquid includes deionized water.

2. The method for non-destructively evaluating the sizing degree of hand-made paper according to claim 1, wherein The paper detection sample is flat, flawless and has uniform texture. Adjust the placement direction to judge the horizontal and vertical directions.

3. The method for non-destructive evaluation of the sizing degree of handmade paper according to claim 1, wherein The paper detection sample is blank, without handwriting and obvious impurities, and the size is not less than 30mm×30mm.

4. The method for non-destructive evaluation of the sizing degree of handmade paper according to claim 1, characterized in that, Accurately suck deionized water with a 5-μL microinjector or micropipette, and touch the liquid drop to the paper surface of the paper detection sample in a gentle way.

5. The method for non-destructive evaluation of the sizing degree of handmade paper according to claim 1, wherein Drop the detection liquid on the paper detection sample, use a high-definition imaging device to record the diffusion process of the detection liquid, analyze frame by frame through video editing software, mark the initial time t1 when the detection liquid touches the paper surface of the paper detection sample and the diffusion stop time t2, and calculate the diffusion time according to the following formula: T = t2 - t1.

6. The method for non-destructive evaluation of the sizing degree of handmade paper according to claim 5, wherein The high-definition imaging device is 15 - 30 cm away from the paper surface, and the frame rate is set to 60 - 120 fps.

7. The method for non-destructively evaluating the sizing degree of handmade paper according to claim 5, characterized in that, The shooting angle of the high-definition imaging device is oblique side shooting, forming an angle of 45° - 60° with the paper surface.

8. The method for non-destructive evaluation of the sizing degree of handmade paper according to claim 1, characterized in that, The measurement of the diffusion distance of the detection liquid is carried out within 1 min after the detection liquid is completely diffused.

9. The method for non-destructive evaluation of the sizing degree of handmade paper according to claim 1, wherein Repeat steps (1) to (2) for multiple paper detection samples made of the same material or multiple positions of the same paper detection sample to obtain the average diffusion time T, the average maximum lateral distance L C , and the average maximum longitudinal distance L M , then perform steps (3) to (4) to obtain the average logarithmic sizing degree Log S, and round it up; Alternatively, repeat steps (1) - (4) using multiple paper detection samples of the same material or multiple positions of the same paper detection sample to obtain the average logarithm sizing degree Log S and round it up.

10. The method for non-destructive evaluation of the sizing degree of handmade paper according to claim 1, wherein, Use the rounded logarithm sizing degree Log S to evaluate the paper sizing degree. The larger Log S is, the higher the sizing degree of the handmade paper is.

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