阅读说明：本技术 一种印刷油墨的检测方法 (Detection method of printing ink ) 是由 梁勇军 苏小燕 于 2021-07-09 设计创作，主要内容包括：本发明涉及印刷技术领域,具体涉及一种印刷油墨的检测方法,依据预设调控条件对车间温湿度和检测条件进行调节；所述印刷油墨使用符合ISO纸白要求的打版纸且颜色参考GRACoL的标准,设定Ecaxt的测量条件；判定所述印刷油墨的色相；以定量标准检验所述印刷油墨的着色力,将待测所述印刷油墨和标准色墨分别冲淡,对比冲淡后油墨的浓度；使用展色仪进行展色,预设所述展色仪的密度从低至高,记录不同密度对应的第一LAB值,并标注展色条上的测量位置；待所述纸张完全干燥之后,再次测量所述测量位置,记录密度值及第二LAB值,并输入表格,本发明解决了现有的印刷产品颜色的正确性和稳定性控制不佳,没有系统的印刷油墨检测流程的问题。(The invention relates to the technical field of printing, in particular to a detection method of printing ink, which adjusts the temperature and the humidity of a workshop and detection conditions according to preset regulation and control conditions; the printing ink uses printing paper meeting the ISO paper white requirement and the color is referred to the standard of GRACoL, and the measuring condition of Ecaxt is set; determining the hue of the printing ink; checking the tinting strength of the printing ink by using a quantitative standard, diluting the printing ink to be tested and the standard color ink respectively, and comparing the concentration of the diluted printing ink; performing color spreading by using a color spreading instrument, presetting the density of the color spreading instrument from low to high, recording first LAB values corresponding to different densities, and marking a measurement position on a color spreading bar; and after the paper is completely dried, measuring the measuring position again, recording the density value and the second LAB value, and inputting a table.)

1. A method for detecting printing ink is characterized in that: it is used for detecting the printing ink; adjusting the temperature and the humidity of the workshop and the detection conditions according to preset adjusting and controlling conditions; the printing ink uses printing paper meeting the ISO paper white requirement and the color is referred to the standard of GRACoL, and the measuring condition of Ecaxt is set; determining the hue of the printing ink; checking the tinting strength of the printing ink by using a quantitative standard, diluting the printing ink to be tested and the standard color ink respectively, and comparing the concentration of the diluted printing ink; performing color spreading by using a color spreading instrument, presetting the density of the color spreading instrument from low to high, recording first LAB values corresponding to different densities, and marking a measurement position on a color spreading bar; after the paper is completely dried, measuring the measuring position again, recording the density value and a second LAB value, and inputting a table; detecting the viscosity of the printing ink according to the printing ink; the solid color sample of the printing ink is divided into two parts, and the two parts are respectively placed in different measuring environments to test the light fastness condition.

2. A method of detecting printing ink as claimed in claim 1, characterized in that: the specific steps for judging the hue of the printing ink are as follows: adjusting the viscosity of the printing ink to the on-machine viscosity, proofing with a printing machine and printing with a solid plate, wherein the printing ink can leave two adjacent color bands on the printing paper at the moment, and judging whether the color phases are the same or not by contrasting the two color bands; if the color phases are the same, the printing ink color phase is qualified.

3. A method of detecting printing ink as claimed in claim 1, characterized in that: the detection method for detecting the tinting strength of the printing ink by using the quantitative standard comprises the specific steps of adding the printing ink to be detected and the standard ink into a beaker, stirring uniformly, printing a plate, comparing by referring to a standard tinting strength color sample, and judging the tinting strength of the ink by percentage.

4. A method of detecting printing ink as claimed in claim 1, characterized in that: the color spreading items are firm, and cannot sand; the monochromatic color of the smallest difference value of the first LAB value and the second LAB value after complete drying cannot exceed 1; ink is taken by using a quantifier for color spreading, wherein the black ink is required to be between 0.28 and 0.3CC, the red and blue ink is required to be between 0.26 and 0.3CC, and the yellow ink is required to be between 0.3 and 0.38 CC.

5. A method of detecting printing ink as claimed in claim 1, characterized in that: the detection of the ink viscosity comprises the following specific steps: and uniformly stirring the printing ink, immersing the viscosity cup in the printing ink, and then extracting the viscosity cup at a constant speed.

6. The method for detecting printing ink as set forth in claim 5, wherein: a stopwatch was pressed immediately after the viscous cup was pulled out of the surface of the printing ink, and the outflow of the printing ink was observed and stopped immediately after the printed ink had a cut-off point.

7. A method of detecting printing ink as claimed in claim 1, characterized in that: the specific steps for testing the light fastness condition are as follows: dividing the solid color sample of the printing ink after printing or plate making into two parts, folding the color sample, placing one part in the sunlight, placing the other part with one part of the printing surface facing upwards, allowing the sunlight to irradiate, and placing one part with the printing surface facing downwards and being in backlight.

8. The method for detecting printing ink as claimed in claim 7, wherein: comparing the color deviation of the two parts of color samples after 4 hours; if no obvious color cast exists, judging that the light resistance of the ink is qualified; and if the color cast is obvious, judging that the light resistance of the ink is not qualified.

9. A method of detecting printing ink as claimed in claim 1, characterized in that: the detection method also comprises the step of detecting the gloss of the printing ink, wherein the gloss is detected by using a radiation gloss meter.

10. A method of detecting printing ink as claimed in claim 9, characterized in that: and if the gloss of the printing ink on the newspaper is more than 8-20% or the gloss of the printing ink on the plastic film is more than 40%, judging that the glossiness of the printing ink is qualified.

Technical Field

The invention relates to the technical field of printing, in particular to a detection method of printing ink.

Background

As printing, paper, and other requirements become higher, the technical requirements for inks also increase. Such as modern high-speed multicolor presses and color-based rotary presses, require that the ink dry at a rate of several seconds or even faster. Glass and gold, silver and coated papers require a glossy ink. Printing a plastic film, wherein the plastic film is required to be well combined with the plastic film; or ink that adheres maximally to the plastic film. Printing special printed matters requires the use of photosensitive ink and the like.

The ink is a uniform mixture composed of color bodies (such as pigments, dyes and the like), binders, filling materials, additives and the like; printing can be carried out, and drying is carried out on the printed body; is a colored pasty adhesive with certain fluidity. Ink is a substance used to form graphic and text information during printing, so the ink has different functions in printing, and directly determines the tone, color, definition and the like of an image on a printed matter. In printing we need to know the composition of the ink and the classification of the ink. Color (hue), body (viscosity, fluidity, and other rheological properties), and drying properties are the three most important properties of an ink. They are of various types, have different physical properties, and are thick and sticky; while some are quite rare. Some vegetable oil is used as a vehicle; some uses resin and solvent or water as the binder. These are determined according to the object to be printed, i.e., the substrate, the printing method, the type of printing plate, the drying method, and the like.

The ink management is mainly to realize the control of the ink color quality parameters through the detection of the hue, the tinting strength and the light fastness of the ink, thereby eliminating color cast from the source. The quality of the ink directly influences the correctness and stability of the color of a printed product. The water-based ink adopted by the flexography has the characteristics of low viscosity and little pollution. The ink detection mainly realizes the control of ink color quality parameters through the detection of the hue, tinting strength and light fastness of the ink, and eliminates color cast from the source. The ink detection and related data can be provided by the supplier or can be detected by the printing enterprise.

Disclosure of Invention

Aiming at the defects of the prior art, the invention discloses a method for detecting printing ink, which is used for solving the problems that the color correctness and stability of the existing printed product are not well controlled and the printing ink detection flow of a system does not exist;

the invention is realized by the following technical scheme:

in a first aspect, the invention discloses a method for detecting printing ink, which is used for detecting the printing ink; adjusting the temperature and the humidity of the workshop and the detection conditions according to preset adjusting and controlling conditions; the printing ink uses printing paper meeting the ISO paper white requirement and the color is referred to the standard of GRACoL, and the measuring condition of Ecaxt is set; determining the hue of the printing ink; checking the tinting strength of the printing ink by using a quantitative standard, diluting the printing ink to be tested and the standard color ink respectively, and comparing the concentration of the diluted printing ink; performing color spreading by using a color spreading instrument, presetting the density of the color spreading instrument from low to high, recording first LAB values corresponding to different densities, and marking a measurement position on a color spreading bar; after the paper is completely dried, measuring the measuring position again, recording the density value and a second LAB value, and inputting a table; detecting the viscosity of the printing ink according to the printing ink; the solid color sample of the printing ink is divided into two parts, and the two parts are respectively placed in different measuring environments to test the light fastness condition.

Preferably, the specific steps of determining the hue of the printing ink are: adjusting the viscosity of the printing ink to the on-machine viscosity, proofing with a printing machine and printing with a solid plate, wherein the printing ink can leave two adjacent color bands on the printing paper at the moment, and judging whether the color phases are the same or not by contrasting the two color bands; if the color phases are the same, the printing ink color phase is qualified.

Preferably, the detection of the tinting strength of the printing ink by using the quantitative standard comprises the specific steps of adding the printing ink to be detected and the standard color ink into a beaker, stirring uniformly, printing a plate, comparing by referring to a standard tinting strength color sample, and judging the tinting strength of the ink by percentage.

Preferably, the color-spreading items are solid and smooth, and cannot sand; the monochromatic color of the smallest difference value of the first LAB value and the second LAB value after complete drying cannot exceed 1; ink is taken by using a quantifier for color spreading, wherein the black ink is required to be between 0.28 and 0.3CC, the red and blue ink is required to be between 0.26 and 0.3CC, and the yellow ink is required to be between 0.3 and 0.38 CC.

Preferably, the detection of the ink viscosity comprises the following specific steps: and uniformly stirring the printing ink, immersing the viscosity cup in the printing ink, and then extracting the viscosity cup at a constant speed.

Preferably, a stopwatch is pressed when the viscous cup is just pulled out of the surface of the printing ink, the outflow of the printing ink is observed, and the stopwatch is pressed immediately when the printing ink has a cut-off point.

Preferably, the specific steps for testing the light fastness condition are as follows: dividing the solid color sample of the printing ink after printing or plate making into two parts, folding the color sample, placing one part in the sunlight, placing the other part with one part of the printing surface facing upwards, allowing the sunlight to irradiate, and placing one part with the printing surface facing downwards and being in backlight.

Preferably, the color deviation of the two parts of the color sample is compared after 4 hours; if no obvious color cast exists, judging that the light resistance of the ink is qualified; and if the color cast is obvious, judging that the light resistance of the ink is not qualified.

Preferably, the detection method further comprises a gloss detection of the printing ink, the gloss detection being measured with a radiation glossmeter.

Preferably, if the gloss of the printing ink on the newspaper is more than 8-20% or the gloss of the printing ink on the plastic film is more than 40%, the glossiness of the printing ink is judged to be qualified.

The invention has the beneficial effects that:

the printing ink is detected, so that the decoration effect of the printing ink is met, and the high reliability and stability of the printing ink are better reflected. The method has the advantages that each production and use index needs to be strictly controlled, the added value is high, the process operation is complex, and the reject ratio and the rejection rate of the product in the use process are reduced. Control indexes and detection representation means of all links in the ink detection process are summarized, and the detection flow of the printing ink is normalized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic flow diagram of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The embodiment discloses a method for detecting printing ink, referring to fig. 1, which is used for detecting printing ink, and the steps of the method for detecting printing ink are as follows:

s1, adjusting the temperature and humidity of the workshop and the detection conditions according to preset adjusting and controlling conditions;

s2, setting the measurement condition of Ecaxt by using printing paper meeting the ISO paper white requirement and the standard of color reference GRACoL;

s3, judging the hue of the printing ink;

the specific steps for judging the hue of the printing ink are as follows: adjusting the viscosity of the printing ink to the on-machine viscosity, proofing with a printing machine and printing with a solid plate, wherein the printing ink can leave two adjacent color bands on the printing paper at the moment, and judging whether the color phases are the same or not by contrasting the two color bands; if the color phases are the same, the printing ink is qualified;

s4, checking the tinting strength of the printing ink by using a quantitative standard, diluting the printing ink to be tested and the standard color ink respectively, and comparing the concentrations of the diluted printing ink;

adding the printing ink to be detected and the standard ink into a beaker, stirring uniformly, printing, comparing with a standard tinting strength color sample, and judging the tinting strength of the ink by percentage;

s5, performing color spreading by using a color spreading instrument, presetting the density of the color spreading instrument from low to high, recording first LAB values corresponding to different densities, and marking measurement positions on color spreading strips;

s6, after the paper is completely dried, measuring the measuring position again, recording the density value and a second LAB value, and inputting a table;

s7, detecting the viscosity of the printing ink according to the printing ink;

the detection of the ink viscosity comprises the following specific steps: uniformly stirring the printing ink, immersing a viscosity cup into the printing ink, and then extracting the viscosity cup at a constant speed; pressing a stopwatch for timing when the viscosity cup is just pulled out of the surface of the printing ink, observing the outflow condition of the printing ink, and immediately pressing a stopwatch for seconds when the printing ink has a cut-off point;

at the moment, the time value on the stopwatch represents the viscosity of the printing ink, the viscosity is high, and the second number is large; low viscosity and small seconds. There is no obvious correlation between the temperature and the color of the printing ink, but there is some influence on the performance of the printing ink. Since the viscosity of the printing ink changes depending on the temperature, the detection temperature is generally fixed at 25 ℃.

And S8, dividing the solid color sample of the printing ink into two parts, and respectively placing the two parts in different measuring environments to test the light fastness.

The light resistance of the ink refers to a property of the ink to maintain color stability after exposure to light. Inks with poor light fastness show fading after a period of exposure to light. Some printed matters meet the requirement of color when printed in a printing factory, and color cast can be generated after the printed matters are used for a period of time at a customer in the process.

The detection method further comprises the step of detecting the gloss of the printing ink, wherein the gloss is detected by using a radiation gloss meter; and if the gloss of the printing ink on the newspaper is more than 8-20% or the gloss of the printing ink on the plastic film is more than 40%, judging that the glossiness of the printing ink is qualified.

The color spreading items are firm, and cannot sand; the monochromatic color of the smallest difference value of the first LAB value and the second LAB value after complete drying cannot exceed 1; ink is taken by using a quantifier for color spreading, wherein the black ink is required to be between 0.28 and 0.3CC, the red and blue ink is required to be between 0.26 and 0.3CC, and the yellow ink is required to be between 0.3 and 0.38 CC. And measuring the density value, and controlling the black ink to dry and fade and not to exceed 0.08, the red and blue ink to exceed 0.02 and the yellow ink to be less than 0.01.

Hue and tinting strength are basic items of ink detection, and have a great influence on the color of printing ink. Hue is a specific characteristic of the color of the ink, and is optically corresponding to light with a certain wavelength and frequency, such as red, yellow and blue. Tinting strength refers to the amount by which one ink affects the degree of color change of another ink. When special color ink is blended, when the hue or the impact of one of the original ink is changed, the color of the blended special color ink is changed. For example, when the original ink has a yellow hue compared to the previous one, the blended spot color ink has an effect of increasing the yellow color; if the coloring power of the red primary ink is strong, the effect of increasing the red color is obtained. The correctness of the hue of the printing ink and the stability of the tinting strength are ensured, and the method is very important for controlling the color of a printed matter.

The detection for detecting the tinting strength of the printing ink comprises the following specific steps:

adding 10g of printing ink to be detected and 100g of standard white ink into a small beaker, uniformly stirring, printing by using a color spreading wheel, comparing a printed color sample with a standard ink tinting strength color chart provided by a supplier, wherein if the ink color is light, the printing ink is weak in tinting strength, if the ink color is dark, the printing ink is strong in tinting strength, and if the ink color is basically consistent, the tinting strength is qualified.

In addition, the degree of the change in the coloring power can be detected by increasing the weight of the printing ink or the standard white ink to be measured. If the ink color is lighter, the weight of the ink to be tested can be properly increased, if 2g of the ink to be tested is added into a small beaker, the mixture is stirred uniformly and then is printed by a color spreading wheel, if the ink color is consistent with the standard color, the color sample is calculated according to the ratio of (10+2):100 ═ 10: x, and then x ═ 100 × 10 ÷ 12 ═ 83.3(g) can be deduced, and the tinting strength of the printing ink is only 83.3% of that of the standard ink, and can also be weakened by 16.7 g.

If the weight of the white ink is suitable for the color depth of the ink, and if the printing color sample is consistent with the standard color card after 10g of standard white ink is added into a small beaker, the value is 110(g) according to the ratio of 10 (100+10) to 10: x, which indicates that the tinting strength of the printing ink to be tested is 1.10% of that of the standard ink, and the strength can also be 10 g.

The x above represents the weight of the white ink when a certain amount of white ink is added into the printing ink to be tested, i.e. the strength of the tinting strength is measured by the amount of the white ink, and the white ink meets the standard tinting strength color chart.

The printing ink is detected, so that the decoration effect of the printing ink is met, and the high reliability and stability of the printing ink are better reflected. The method has the advantages that each production and use index needs to be strictly controlled, the added value is high, the process operation is complex, and the reject ratio and the rejection rate of the product in the use process are reduced. Control indexes and detection representation means of all links in the ink detection process are summarized, and the detection flow of the printing ink is normalized.

Example 2

This embodiment discloses a method for detecting printing ink according to embodiment 1, and further provides a method for comparing and comparing wet color samples to detect the tinting strength of the printing ink, wherein the wet color samples to be detected and the tinting strength detection wet color samples of the printing ink judged to be qualified are arranged in parallel on a color wheel, and the wet color samples are compared after being printed.

The detection method of the embodiment eliminates the defect that the color deviation exists between the wet color sample and the dry color sample, which has bad influence on the real result evaluation, and the color is convenient to compare and the accuracy is higher because the wet color samples are adjacent.

After the tinting strength and hue detection is finished, the wet color sample and the dry color sample during the detection are surely kept, particularly the wet color sample and the dry color sample of the standard ink are required to be sealed and kept and marked for use in the next detection. The spot color requires stable color, so the color phase of the ink requires correct color and the tinting strength requires stable, and the general standard is that the ink can be accepted within +/-10 percent and qualified within +/-5 percent, and cannot be higher or lower.

The printing ink is detected, so that the decoration effect of the printing ink is met, and the high reliability and stability of the printing ink are better reflected. The method has the advantages that each production and use index needs to be strictly controlled, the added value is high, the process operation is complex, and the reject ratio and the rejection rate of the product in the use process are reduced. Control indexes and detection representation means of all links in the ink detection process are summarized, and the detection flow of the printing ink is normalized.

Example 3

This example discloses a method for detecting the coloring power of the printing ink of example 2, which comprises the following steps:

s101, weighing 2g of standard white ink and 0.2g of sample ink on a round glass sheet by using an analytical balance. Weighing standard white ink and standard ink in the same proportion by the same method; fully and evenly mixing the weighed ink by using ink mixing blades respectively;

s102, taking about 0.5g of a uniformly mixed standard sample by using a toning knife, coating the uniformly mixed standard sample on the left upper part of the scraping paper, taking about 0.5g of a uniformly mixed sample, coating the uniformly mixed sample on the right upper part of the scraping paper, and enabling the uniformly mixed standard sample and the scraping paper to be adjacent and unconnected;

s103, placing a scraping blade above the coated ink sample to enable the main body part of the scraping blade to be perpendicular to the sample scraping paper; then, the ink is scraped into a thin layer on the sample scraping paper from top to bottom, when the thickness of the ink layer is 35-45mm, the force is reduced, the angle of the inner side of the scraping blade is approximate to 25 degrees, and the ink is coated on the paper into a thicker ink layer. The final scratch shape should be similar to the schematic in GB/T14624.1;

s104, observing whether the surface color and the ink color of the sample are consistent or not, if not, changing the consumption of the standard white ink of the sample until the diluted sample is consistent with the standard sample, and calculating according to a formula to obtain the percentage of the tinting strength of the sample;

s105, scraping the sample, and then observing the reflected ink color within 30S.

The printing ink is detected, so that the decoration effect of the printing ink is met, and the high reliability and stability of the printing ink are better reflected. The method has the advantages that each production and use index needs to be strictly controlled, the added value is high, the process operation is complex, and the reject ratio and the rejection rate of the product in the use process are reduced. Control indexes and detection representation means of all links in the ink detection process are summarized, and the detection flow of the printing ink is normalized.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.