Printing ink fluidity inspection method

1. Inspection principle

Place a certain volume of ink in the center of two parallel circular glass plates, apply a certain pressure, and after a certain period of time at a certain temperature, the diameter of the expanded cylinder is called the ink fluidity, expressed in millimeters.

Fluidity can be simply considered as an indicator for measuring the thinness, thickness and viscosity of ink. It has certain reference significance for production control and guidance.

2. Tools and materials

(1) A set of fluidity Tester (one weight weighing 200 grams, two pieces of round glass weighing 50 grams with a diameter of 65-70 mm, and one metal fixed plate);

(2) One 0.1ml suction tube;

(3) Transparent ruler;

(4) Ink adjusting knife;

(5) glass plate;

(6) One low-temperature Incubator (insulation sensitivity ±1°C);

(7) Set the clock.

3. Inspection method

(1) Place the fluidity Tester and the ink sample in a thermostat at 25±1°C for 20 minutes (the fluidity Tester needs to be kept in a thermostat), or measure in a thermostatic chamber that meets the requirements of this method.

(2) Take a small amount of ink (about 2~3 grams) and put it on the glass plate with the ink adjustment method, transfer the ink 15 times (one round trip), absorb 0.1 ml of ink with the ink suction tube, and remove the remaining ink around the nozzle. Scrape off with an ink spatula, keeping the ink level with the nozzle (be careful not to trap air when absorbing the ink).

(3) Squeeze out the ink in the ink-absorbing tube, scrape off the center of the glass sheet dripping in the metal fixed disc (with a constant temperature of 25±1°C) with an ink-adjusting knife, and use the ink-adjusting knife to remove the remaining ink from the ink-absorbing tube core Shave carefully and apply to the center of the upper round glass.

(4) Put the upper round glass on the round glass in the metal fixed plate, so that the ink parts in the two centers overlap, immediately press the weight, put it in the constant temperature box, start to count the time, and keep it warm at 25±1°C. (When placed in an Incubator, do not tilt and keep it level)

(5) Take it out after 15 minutes, remove the weight, and measure twice with a transparent measuring ruler to get the average value. If the difference between the two measurement results is more than 2mm, the test needs to be redone. 4. Precautions

(1) The fixed metal plate needs to be placed on a horizontal flat surface to prevent tilting, otherwise the movement of the round glass will cause the ink to form an ellipse after being pressed, making the value inaccurate.

(2) The ink suction tube needs to be wiped clean after use.

(3) When measuring the expansion diameter of the ink with a transparent ruler, the eyes should be perpendicular to the scale to avoid errors.