A detection device for detecting the printing quality of printed paper products

Abstract

The invention relates to the technical field of printed product quality detection, and specifically discloses a detection device for detecting the printing quality of printed paper products. The ink coverage is calculated by acquiring the ink density of the printed area of ​​the paper and the density of the blank space, and the printing score Qi is calculated in combination with the quality difference before and after the paper is printed, and then compared with a preset printing score threshold to generate a printing qualified or unqualified signal; the pressure abnormality factor MF and the temperature abnormality factor MT are calculated by acquiring printing pressure and temperature data, and the printing process abnormality score S is obtained by combining the two, and then compared with the preset threshold to generate a printing process normal or abnormal signal; the correlation coefficient r between the printing score and the printing process abnormality score is calculated through correlation analysis, and the process parameters are adjusted according to the correlation to optimize the printing quality; the invention effectively improves the consistency and stability of printing quality by real-time monitoring of key parameters in the printing process and performing intelligent adjustments.

Description

Technical Field

[0001] The present invention relates to the technical field of printed product quality detection, and in particular to a detection device for detecting the printing quality of printed paper products. Background Art

[0002] With the continuous development of the printing industry, the quality requirements for printed products are increasing. In order to ensure the quality and consistency of the final product, strict quality monitoring of printed products is required during the printing process. Traditional quality monitoring methods usually rely on manual visual inspection, which is not only inefficient but also easily affected by subjective factors, making it difficult to ensure the consistency and accuracy of detection. In addition, existing automatic detection systems often focus on detecting surface defects of printed products, while ignoring the impact of the printing process itself on printing quality. Therefore, the development of a detection device and method that can comprehensively consider the impact of printing process parameters (such as printing pressure and printing temperature) on printing quality is of great significance to improving the overall quality of printed products.

[0003] Existing technologies lack effective methods for quantifying ink coverage and its impact on paper quality, resulting in an inability to accurately evaluate printing quality; traditional printing processes may not integrate pressure sensors and temperature sensors, making it difficult to monitor changes in these key parameters in real time, and making it impossible to make timely adjustments to maintain process stability; in existing technologies, evaluation of printing quality may be based on manual inspection or inaccurate standards, lacking an objective and quantitative evaluation system; existing technologies may not make full use of historical data to optimize process parameters, resulting in the inability to effectively improve printing results even if anomalies are discovered; traditional methods may not conduct in-depth analysis of the correlation between printing scores and process anomalies, and therefore cannot clearly identify which process factors actually affect printing quality. Summary of the invention

[0004] The printing pressure data and printing temperature data are collected by the pressure sensor and temperature sensor installed on the printing machine. By processing these data, the pressure abnormality factor MF and the temperature abnormality factor MT are obtained. Then, the printing process abnormality score S is calculated based on these two factors, and compared with the preset printing process abnormality score threshold, so as to generate a signal that the printing process is normal or abnormal. The printing pressure data and printing temperature data are collected by the pressure sensor and temperature sensor installed on the printing machine. By processing these data, the pressure abnormality factor MF and the temperature abnormality factor MT are obtained. Then, the printing process abnormality score S is calculated based on these two factors, and compared with the preset printing process abnormality score threshold, so as to generate a signal that the printing process is normal or abnormal. The printing score Qi and the printing process abnormality score S are correlated and the correlation coefficient r is calculated. If the correlation coefficient r is greater than 0, it means that there is a positive correlation between the printing score and the printing process abnormality score, that is, the printing process abnormality will cause the paper printing to be unqualified. Otherwise, there is no correlation. The normal printing pressure data and printing temperature data are obtained in the historical working cycle, and they are processed to obtain the normal printing pressure range and the normal printing temperature range. In the following working cycle, the process parameters of the printing press are adjusted according to these intervals to ensure the stability of the printing process and the high quality of the printed products.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A detection device for detecting the printing quality of printed paper products, comprising a data acquisition module, a data processing module, a decision module and an execution module;

[0007] A data acquisition module, which measures the ink density of the printed area and the blank area by using a densitometer, measures the paper weight before and after printing by using an electronic balance, and monitors the printing pressure and printing temperature in real time by using a pressure sensor and a temperature sensor;

[0008] A data processing module, wherein the data processing module calculates the ink coverage rate according to the ink density; calculates the printing score based on the ink coverage rate of the paper and the quality difference before and after printing; calculates the printing process abnormality score according to the pressure data and the temperature data; and calculates the correlation coefficient between the printing score and the printing process abnormality score;

[0009] A decision module, wherein the decision module determines whether the paper is qualified according to the printing score; determines whether there is a printing process abnormality according to the printing process abnormality score; and gives adjustment suggestions according to the correlation analysis results;

[0010] An execution module adjusts the pressure and temperature settings of the printing press according to the results of the decision module.

[0011] As a further solution of the present invention: the process of obtaining the printing score Qi is:

[0012] The printing score Qi is calculated.

[0013] Furthermore, the pressure data is processed to obtain the pressure abnormality factor MF;

[0014] During the printing cycle, the real-time printing pressure value Fj is collected in time series by the pressure sensor;

[0015] Wherein, j represents the number of acquisition points, j=1, 2, ..., n; all printing pressure values ​​are integrated to obtain a printing pressure value group;

[0016] By processing the average printing pressure value Fy and the standard deviation value α1, the pressure variation coefficient CF is obtained;

[0017] The pressure abnormality factor MF is calculated.

[0018] Furthermore, the temperature data is processed to obtain the temperature anomaly factor MT;

[0019] During the printing cycle, the real-time printing temperature value Tj is collected in time series by the temperature sensor;

[0020] The temperature anomaly factor MT number is calculated.

[0021] Furthermore, the process of obtaining the printing process abnormality score S is as follows:

[0022] The weight of the pressure anomaly factor MF is assigned to w1, and the weight of the temperature anomaly factor MT is assigned to w2;

[0023] The printing process abnormality score S is calculated.

[0024] Furthermore, the process of obtaining the correlation coefficient r is:

[0025] Obtain the printing score Qi and the printing process abnormality score Si of each paper when it is printed;

[0026] The correlation coefficient r was calculated.

[0027] Furthermore, if the correlation coefficient r is greater than 0, it indicates that there is a positive correlation between the printing score Qi and the printing process abnormality score Si, and an influence signal is generated;

[0028] If the correlation coefficient r is less than or equal to 0, it means that there is no correlation between the printing score Qi and the printing process abnormality score Si, and a non-influence signal is generated.

[0029] Furthermore, the process of obtaining the normal printing temperature range [Tg, Ts] is as follows:

[0030] Get all normal temperature values ​​Tz in the historical period;

[0031] Calculate the normal temperature fluctuation ratio w T ;

[0032] The temperature upper limit threshold Ts is calculated;

[0033] The lower temperature threshold Tg is calculated;

[0034] Among them, Tq is the optimal printing temperature of the preset printing machine, Ty is the average normal temperature value, Tmax is the maximum temperature value, and Tmin is the minimum temperature value.

[0035] Furthermore, the process of obtaining the normal printing pressure range [Fg, Fs] is as follows:

[0036] Get all normal pressure values ​​Fm in the historical period;

[0037] Calculate the normal pressure fluctuation ratio W F ;

[0038] The pressure upper limit threshold Fs is calculated;

[0039] The pressure lower limit threshold Fg is calculated;

[0040] Among them, Fq is the optimal printing pressure of the preset printing press, Fy is the average normal pressure value, Fmax is the maximum pressure value, and Tmin is the minimum pressure value.

[0041] As a further solution of the present invention: in the next working cycle of the printing machine, the printing temperature is adjusted to always remain in the normal temperature range [Tg, Ts], and the printing pressure is adjusted to always remain in the normal pressure range [Fg, Fs].

[0042] Beneficial effects of the present invention:

[0043] (1) By real-time monitoring and calculating the ink coverage of the paper and the quality difference before and after printing, the printing degree of each sheet of paper can be accurately evaluated, thereby ensuring the consistency of printing quality; in addition, by calculating the printing score and comparing it with the preset threshold, abnormal conditions in the printing process can be discovered in time, and a printing pass or fail signal can be generated, which helps to respond quickly and avoid the production of a large number of failed products; more importantly, by analyzing and adjusting the printing process data (such as printing pressure and temperature), the stability and controllability of the printing process can be further improved, thereby ensuring that each batch of printed products can meet high standards of quality requirements; therefore, this embodiment can significantly improve the consistency and stability of printed products, reduce the scrap rate, and improve customer satisfaction;

[0044] (2) Through real-time monitoring and analysis of key parameters in the printing process (such as ink coverage, quality difference before and after printing, printing pressure and temperature, etc.), the system can automatically calculate the printing score and process abnormality score, and automatically adjust the process parameters of the printing press, such as printing pressure and temperature, based on these scores; such intelligent adjustment not only reduces the need for human intervention, but also can respond quickly according to actual conditions to ensure the efficient progress of the printing process; in addition, through the analysis and learning of historical data, the system can also continuously optimize the process parameter settings to further improve printing efficiency and quality. Therefore, this embodiment not only improves the intelligence and automation level of the printing process, but also reduces production costs and enhances the competitiveness of enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will be further described below in conjunction with the accompanying drawings.

[0046] Figure 1 It is a flowchart of the specific steps of a detection device for detecting the printing quality of printed paper products of the present invention;

[0047] Figure 2 It is a flow chart of a standard for judging the printing score of a detection device for detecting the printing quality of printed paper products in the present invention;

[0048] Figure 3 The present invention is a flow chart of a standard for judging the abnormality score of a printing process of a detection device for detecting the printing quality of printed paper products. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Example 1

[0051] See also Figure 1 As shown, the present invention is a detection device for detecting the printing quality of printed paper products, including a data acquisition module, a data processing module, a decision module and an execution module;

[0052] A data acquisition module, which measures the ink density of the printed area and the blank area by using a densitometer, measures the paper weight before and after printing by using an electronic balance, and monitors the printing pressure and printing temperature in real time by using a pressure sensor and a temperature sensor;

[0053] A data processing module, wherein the data processing module calculates the ink coverage rate according to the ink density; calculates the printing score based on the ink coverage rate of the paper and the quality difference before and after printing; calculates the printing process abnormality score according to the pressure data and the temperature data; and calculates the correlation coefficient between the printing score and the printing process abnormality score;

[0054] A decision module, wherein the decision module determines whether the paper is qualified according to the printing score; determines whether there is a printing process abnormality according to the printing process abnormality score; and gives adjustment suggestions according to the correlation analysis results;

[0055] An execution module adjusts the pressure and temperature settings of the printing press according to the results of the decision module.

[0056] Example 2

[0057] See also Figure 2 As shown, based on Example 1, during the processing cycle of the printing press, a densitometer is used to measure the ink density RYi of the printed area of ​​each paper, and the ink density of the printed area is calculated with the density RB i of the blank area to obtain the ink coverage rate ai of each paper;

[0058] Wherein, i represents the number of collected papers, i=1, 2, ..., n;

[0059] The weight of paper before and after printing is collected by electronic balance;

[0060] Get the paper weight HSi before printing;

[0061] Get the weight of the printed paper HMi;

[0062] The quality difference ΔHi before and after printing of paper is calculated by the formula ΔHi=HMi-HSi;

[0063] Process the ink coverage ai of each paper and the quality difference ΔHi before and after printing of each paper;

[0064] By formula Calculate and obtain the printing score Qi;

[0065] Wherein, b1 and b2 are preset proportional factors, and both b1 and b2 are greater than 0;

[0066] Compare the printing score Qi of the paper with a preset printing score threshold;

[0067] If the printing score Qi of the paper is greater than or equal to the preset printing score threshold, it indicates that the corresponding paper is printed abnormally, and a printing failure signal is generated;

[0068] If the printing score Qi of the paper is less than the preset printing score threshold, it means that the corresponding paper is printed normally, and a printing qualified signal is generated;

[0069] It should be noted that the printing score Qi is an evaluation standard that reflects the quality of paper printing. Timely testing of the paper printing degree can effectively prevent losses caused by printing abnormalities.

[0070] Example 3

[0071] See also Figure 3 As shown, based on Example 2, since the abnormal printing process when the printing machine is in use may cause the paper to be unqualified, it is analyzed and determined whether the unqualified printing when the printing machine is in use is related to the abnormal printing process when the printing machine is in use. If there is a relationship of the influence of the printing process, it is convenient to adjust the printing process in time during the subsequent use of the printing machine, reduce the influence of the printing process on the unqualified printing during the use of the printing machine, and thus improve the printing qualification rate when the printing machine is in use;

[0072] Among them, the printing process includes: printing pressure and printing temperature;

[0073] Specific:

[0074] Install pressure sensors and temperature sensors on the printing press and calibrate them to ensure the accuracy of collected data;

[0075] During the printing cycle, the real-time printing pressure value Fj is collected by the pressure sensor in a time series (e.g., every minute);

[0076] Wherein, j represents the number of acquisition points, j=1, 2, ..., n;

[0077] Integrate all printing pressure values ​​to obtain a printing pressure value group;

[0078] The average printing pressure value Fy of the printing pressure value group is calculated by the mean calculation formula;

[0079] By formula The standard deviation α1 of the pressure value group is calculated;

[0080] By formula The pressure variation coefficient CF is calculated;

[0081] By formula The pressure abnormality factor MF is calculated;

[0082] Wherein, b3 and b4 are preset proportional factors, and both b3 and b4 are greater than 0;

[0083] During the printing cycle, the real-time printing temperature value Tj is collected by the temperature sensor in a time series (e.g., every minute);

[0084] Integrate all printing temperature values ​​to obtain a printing temperature value group;

[0085] The average printing temperature value Ty of the printing temperature value group is calculated by the mean calculation formula;

[0086] By formula Calculate the standard deviation α2 of the printing temperature value group;

[0087] By formula The temperature anomaly factor MT is calculated;

[0088] Wherein, b5 and b6 are preset proportional factors, and both b5 and b6 are greater than 0;

[0089] Process the pressure anomaly factor MF and the temperature anomaly factor MT;

[0090] The weight of the pressure anomaly factor MF is assigned to w1, and the weight of the temperature anomaly factor MT is assigned to w2;

[0091] The printing process abnormality score S is calculated by the formula S=MF*w1+MT*w2;

[0092] Compare the printing process abnormality score S with a preset printing process abnormality score threshold;

[0093] If the printing process abnormality score S is greater than or equal to the preset printing process abnormality score threshold, it indicates that the printing process is abnormal, and a printing process abnormality signal is generated;

[0094] If the printing process abnormality score S is less than the preset printing process abnormality score threshold, it means that the printing process is normal, and a printing process normal signal is generated;

[0095] It should be noted that the printing process abnormality score S is used to evaluate the degree to which the printing machine is affected by printing temperature and printing pressure. The larger the printing process abnormality score S, the worse the printing effect.

[0096] Example 4

[0097] On the basis of Example 3, a correlation analysis is performed between the printing score and the printing process abnormality score to determine the influence relationship between the two. If there is an influence relationship, it means that the printing process abnormality will cause the paper printing to be unqualified.

[0098] Specific:

[0099] Obtain the printing score Qi and the printing process abnormality score Si of each paper when it is printed;

[0100] During the printing cycle, obtain the printing score Qi of all papers;

[0101] The average printing score Qy of all papers is calculated by the mean calculation formula;

[0102] Get the printing process abnormality score Si of all papers;

[0103] The average printing process abnormality score Sy of all papers is calculated by the mean calculation formula;

[0104] By formula The correlation coefficient r was calculated;

[0105] Among them, the value range of the correlation coefficient r is [-1,1];

[0106] If the correlation coefficient r is greater than 0, it means that there is a positive correlation between the printing score Qi and the printing process abnormality score Si, indicating that the printing process abnormality will cause paper printing to be unqualified and generate an impact signal;

[0107] If the correlation coefficient r is less than or equal to 0, it means that there is no correlation between the printing score Qi and the printing process abnormality score Si, indicating that there is no direct influence relationship between the printing process abnormality and the unqualified paper printing, and a non-influence signal is generated;

[0108] It should be noted that the calculation of the correlation coefficient r can clearly reflect the relationship between the printing process and the degree of paper printing, and can accurately analyze the problems that occur in the printing process and make timely repairs.

[0109] Example 5

[0110] On the basis of Example 4, based on the influencing signal, normal printing pressure data and printing temperature data within a historical working cycle are obtained, wherein the obtained data needs to be preprocessed to remove abnormal values ​​to ensure the accuracy of the data.

[0111] Get all normal temperature values ​​Tz within the cycle;

[0112] Integrate all normal temperature values ​​Tz to obtain a normal temperature value group;

[0113] Wherein, z represents the number of temperature values, z=1, 2, ..., n;

[0114] The average normal temperature value Ty in the normal temperature value group is calculated according to the mean calculation formula;

[0115] Get the maximum temperature value Tmax in the normal temperature value group;

[0116] Get the minimum temperature value Tmin in the normal temperature value group;

[0117] By formula Calculate the normal temperature fluctuation ratio w T ;

[0118] By the formula Ts = Tq*(1+W T ) Calculate the upper temperature threshold Ts;

[0119] By the formula Tg = Tq*(1-W T ) Calculate the lower temperature threshold Tg;

[0120] Wherein, Tq is the optimum printing temperature of the preset printing press;

[0121] Get the normal printing temperature range [Tg, Ts];

[0122] Get all normal pressure values ​​Fm within the cycle;

[0123] Integrate all normal pressure values ​​Fm to obtain a normal pressure value group;

[0124] Wherein, m represents the number of pressure values, m=1, 2, ..., n;

[0125] The average normal pressure value Fy in the normal pressure value group is calculated according to the mean calculation formula;

[0126] Get the maximum pressure value Fmax in the normal pressure value group;

[0127] Get the minimum pressure value Fmin in the normal pressure value group;

[0128] By formula Calculate the normal pressure fluctuation ratio W F ;

[0129] By the formula Fs = Fq*(1+W F ) Calculate the upper pressure threshold Fs;

[0130] By the formula Fg = Fq*(1-W F ) Calculate the pressure lower limit threshold Fg;

[0131] Among them, Fq is the optimal printing pressure of the preset printing press;

[0132] Get the normal range of printing pressure [Fg, Fs];

[0133] In the next working cycle of the printing press, the printing temperature is adjusted to always remain within the normal temperature range [Tg, Ts], and the printing pressure is adjusted to always remain within the normal pressure range [Fg, Fs].

[0134] It should be noted that maintaining normal printing pressure and printing temperature is the key to ensuring that the paper is printed properly during the printing process, thereby reducing the scrap rate of paper.

[0135] The working principle of the present invention is as follows: In step S1, the ink density of the printed area of ​​the paper (denoted as RYi) and the density of the blank area (denoted as RBi) are obtained, and the ink coverage rate of the paper (denoted as ai) is obtained after processing. Then, the paper quality before and after printing is measured by an electronic balance, and the quality difference before and after printing is calculated. Then, the ink coverage rate ai is combined with the quality difference before and after printing, and the printing score Qi is calculated by the preset proportional factors b1 and b2. Finally, the printing score Qi is compared with the preset printing score threshold to generate a printing qualified or unqualified signal. This step ensures an objective evaluation of the printing quality and can detect printing abnormalities in a timely manner.

[0136] Secondly, the pressure sensor and temperature sensor installed on the printing machine are used to collect printing pressure data and printing temperature data. By processing these data, the pressure abnormality factor MF and the temperature abnormality factor MT are obtained. Then, the printing process abnormality score S is calculated based on these two factors and compared with the preset printing process abnormality score threshold to generate a signal that the printing process is normal or abnormal. This step helps to identify the pressure and temperature abnormalities that may occur during the printing process, thereby further improving the printing quality.

[0137] Then, the printing score Qi and the printing process abnormality score S are subjected to correlation analysis to calculate the correlation coefficient r. If the correlation coefficient r is greater than 0, it means that there is a positive correlation between the printing score and the printing process abnormality score, that is, the printing process abnormality will lead to unqualified paper printing. Otherwise, there is no correlation. Through this analysis, it can be determined whether the printing process data has an impact on paper printing.

[0138] Finally, based on the results of the above correlation analysis, the normal printing pressure data and printing temperature data are obtained from the historical working cycle, and processed to obtain the normal printing pressure range and the normal printing temperature range. In the next working cycle, the process parameters of the printing press are adjusted according to these ranges to ensure the stability of the printing process and the high quality of the printed products.

[0139] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A detection device for detecting the printing quality of printed paper, characterized in that: It includes data acquisition module, data processing module, decision-making module and execution module; A data acquisition module, which measures the ink density of the printed area and the blank area by using a densitometer, measures the paper weight before and after printing by using an electronic balance, and monitors the printing pressure and printing temperature in real time by using a pressure sensor and a temperature sensor; A data processing module, wherein the data processing module calculates ink coverage according to ink density; The printing score is calculated based on the ink coverage of the paper and the quality difference before and after printing; Calculate the printing process abnormality score based on the pressure data and the temperature data; Calculate the correlation coefficient between the printing score and the printing process abnormality score; A decision module, wherein the decision module determines whether the paper is qualified according to the printing score; and determines whether there is a printing process abnormality according to the printing process abnormality score; Provide adjustment suggestions based on the correlation analysis results; an execution module, the execution module adjusting the pressure and temperature settings of the printing press according to the results of the decision module; The process of obtaining the correlation coefficient r is: Obtain the printing score Qi and the printing process abnormality score Si of each paper when it is printed; The correlation coefficient r was calculated; If the correlation coefficient r is greater than 0, it means that there is a positive correlation between the printing score Qi and the printing process abnormality score Si, generating an influence signal; If the correlation coefficient r is less than or equal to 0, it means that there is no correlation between the printing score Qi and the printing process abnormality score Si, and a non-influence signal is generated.

2. A detection device for detecting the printing quality of printed paper according to claim 1, characterized in that: The process of obtaining the printed score Qi is: The printing score Qi is calculated.

3. The detection device for detecting the printing quality of printed paper according to claim 1, characterized in that: The pressure data is processed to obtain the pressure abnormality factor MF; During the printing cycle, the real-time printing pressure value Fj is collected in time series by the pressure sensor; Wherein, j represents the number of acquisition points, j=1, 2, ..., n; all printing pressure values ​​are integrated to obtain a printing pressure value group; By processing the average printing pressure value Fy and the standard deviation value α1, the pressure variation coefficient CF is obtained; The pressure abnormality factor MF is calculated.

4. The detection device for detecting the printing quality of printed paper according to claim 1, characterized in that: The temperature data is processed to obtain the temperature anomaly factor MT; During the printing cycle, the real-time printing temperature value Tj is collected in time series by the temperature sensor; The temperature anomaly factor MT number is calculated.

5. The detection device for detecting the printing quality of printed paper according to claim 1, characterized in that: The process of obtaining the printing process abnormality score S is as follows: The weight of the pressure anomaly factor MF is assigned to w1, and the weight of the temperature anomaly factor MT is assigned to w2; The printing process abnormality score S is calculated.

6. The detection device for detecting the printing quality of printed paper according to claim 1, characterized in that: The process of obtaining the normal printing temperature range [Tg, Ts] is as follows: Get all normal temperature values ​​Tz in the historical period; Calculate the normal temperature fluctuation ratio w T ; The upper temperature threshold Ts is calculated; The lower temperature threshold Tg is calculated; Among them, Tq is the optimal printing temperature of the preset printing machine, Ty is the average normal temperature value, Tmax is the maximum temperature value, and Tmin is the minimum temperature value.

7. The detection device for detecting the printing quality of printed paper according to claim 1, characterized in that: The process of obtaining the normal printing pressure range [Fg, Fs] is as follows: Get all normal pressure values ​​Fm in the historical period; Calculate the normal pressure fluctuation ratio W F ; The upper pressure threshold Fs is calculated; The pressure lower limit threshold Fg is calculated; Among them, Fq is the optimal printing pressure of the preset printing press, Fy is the average normal pressure value, Fmax is the maximum pressure value, and Tmin is the minimum pressure value.

8. The detection device for detecting the printing quality of printed paper according to claim 1, characterized in that: In the next working cycle of the printing press, the printing temperature is adjusted to always remain within the normal temperature range [Tg, Ts], and the printing pressure is adjusted to always remain within the normal pressure range [Fg, Fs].

Images