Ink quality inspection method

Ink color inspection method

principle

Compare the color sample with the standard sample spreader and check whether the sample color meets the standard

Tools and materials

1. Mold Adjusting Knife 2. Color Developing Machine 3. White Paper 4. Cow Cardboard

Inspection steps:

※ Take appropriate amount of standard sample with the dip knife on the left and right side of the colorimeter. Take appropriate amount of sample on the right side of the colorimeter. The two ink samples should not be connected adjacently. ※ Place the colorimeter on the selected card. Uniform color development from top to bottom ※ After the ink is dry, check the color of the sample and the sample at different angles of the light source Note ※ The viscosity of the standard ink sample and the sample should be as close as possible. ※ The standard ink sample and the sample should be well mixed

Ink abrasion resistance test method

principle

After the ink is printed on the print, it must have a certain degree of abrasion resistance in order to reduce or prevent the print from being dirty or discolored during transportation, storage and use.

Tools and materials

1. Standard white card 2. Ink knife 3. Color meter 4. Wear resistance meter 5. Blank standard paper 6. 500g code

Inspection procedure

※ Stir the ink under test on a standard white card paper and leave it to dry for a certain period of time. ※ Fix the dried ink on the abrasion resistance meter, and fix the standard paper to place the blank standard paper on the tested ink. On color paper, start anti-wear under 500G pressure, make 100 round trips

Precautions

※ This method is difficult to quantify the experimental results, but it can be judged by comparing the advantages and disadvantages of ink abrasion resistance. ※ It can be rated according to the dyeing condition of the blank standard paper, which indicates the good or bad anti-wear performance.

Ink PH test method

principle

The level of PH is an important indicator of ink quality. The pH value of ink will affect the viscosity, abrasion resistance and stability of the ink, so it must be controlled within a certain range.

Tools and materials

1. PH meter 2. Thermometer

Inspection procedure

※ Calibrate the pH meter with buffer ※ Measure the temperature of the tested ink and control the temperature with the thermostat 250C
※ Adjust the pH meter temperature knob to 250C, open the switch, insert the electrode end into the tested ink and keep stirring. When the PH meter reads a fixed value, it is the PH value of the tested ink.

Precautions

Tested ink must be fully mixed

Ink viscosity testing method

principle

Viscosity is one of the important properties of a fluid. It is a measure of the relative motion of intermolecular fluid molecules that hinders the relative movement between molecules, and measures the internal resistance of fluid flow.

Tools and materials

1. Stick ring cup 2. Thermometer 3. Stopwatch

Inspection procedure

※ Determine the temperature of the tested ink, use a thermostat to control its temperature 250C
※ Make the viscosity cup filled with the tested ink and let the ink flow out from the cup hole. At the same time press the stopwatch to start timing and stop the stopwatch when the ink flows out of the ink for the first time.
※ The reading seconds is the ink relative viscosity in seconds.

note

※ When the ink begins to flow from the viscosity cup cup hole, it should start timing according to the stopwatch. When the ink is cut off for the first time, stop the stopwatch.
※ In order to avoid errors caused by the operator's operation method, the average is usually measured three times.

Remarks:
1. The ink usually reduces its viscosity under the action of external force (stirring and shaking), and restores the original viscosity after a period of time. This performance is called degeneration.
2. The ink is circulated on the machine for about 5 minutes before measuring the viscosity
3. Note the amount of ink added is 0.2 - 0.5%
4. Adding thickener must be slowly added when adding, while adding
5. Underprint pressure is reduced as much as possible
6. The difference in viscosity between the second color is at least 5 seconds
7. The correct expression of fluidity refers to the pressure of the ink and its degree of friction to indicate
8. The most stable oil pH is between 8.5 - 9.2.