The difference and relation between printing visco

2022-07-23
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The difference and relationship between printing viscosity and viscosity of temperature variable inks

how to control the printing viscosity of inks is a key problem in plastic gravure printing. Especially in high-speed rotary gravure printing, whether the printing viscosity control of temperature variable ink is appropriate is directly related to most quality problems, such as pigment transfer, dirty plate, print gloss brightness, pigment bonding firmness, static electricity, etc., which affect the yield of prints and work efficiency. So, in plastic gravure printing, how to control the ink printing viscosity, so as to give consideration to many aspects and ensure the quality of quenched printed products with the processing waste heat. This requires us to first take the 5V supply voltage to understand the two concepts of ink printing viscosity and viscosity. According to the relevant textbooks or materials, the overview of the relationship between the two is usually very vague. Some even regard the two as a concept. In fact, there are obvious differences between the two. The following points are summarized to explain the differences and relations between ink printing viscosity and viscosity

1. Different definitions of temperature dependent inks

if the flow velocity of each layer of the ink is different due to some external reasons, especially there is a force and reaction force between the two liquid layers with different flow velocity on the contact surface, this pair of forces is called the internal friction force of the maintenance of the ink Jinan assay friction and wear tester, and the nature it shows is called the viscosity of the ink. The physical measure of ink viscosity is called viscosity

2. Differences in performance modes of temperature dependent inks

stickiness occurs when the ink film is resistant to separation, and the fluid only shows stickiness when flowing, and does not show stickiness in static fluid. The effect of viscosity is to block the relative sliding inside the fluid, so as to block the flow of the fluid, but this blocking effect can only delay the relative sliding process and can not stop it. This is an important characteristic of fluid viscosity, and it is a rheological parameter that represents the internal adhesion characteristics of fluid. Viscosity is a measure of the internal friction between molecules when a liquid moves under an external force. Viscosity is an attribute of a fluid. It always exists whether the fluid is at rest or flowing

3. The quality of warm soil is getting worse and worse. The testing method and unit of ink are different. The viscosity is measured by rotating viscometer. Measure the resistance caused by the separation of the ink or binder film with a viscosimeter. The viscosity value is expressed in numbers. Viscosity has no unit

there are many methods to measure viscosity. There are capillary viscometer, small hole viscometer, rotary viscometer and rotary cone plate viscometer. Generally, rotary viscometer is used to measure the viscosity of ink. When the rotor is subject to the viscous resistance of the liquid, the hairspring will generate torque to counter the viscous resistance and finally reach equilibrium. At this time, the pointer connected with the hairspring will indicate a certain reading on the scale disc (i.e. the torsion angle of the hairspring). Multiply the reading by a specific coefficient to obtain the viscosity of the liquid. This shows that viscosity and viscosity are different in units

4. Different influencing factors

the factors affecting the viscosity include: the diameter, hardness and elastic modulus of the elastic roll, the nature of the roll, the speed of the roll, the temperature of the roll, the ambient temperature and humidity, the temperature of the sample, the thickness of the ink film, the influence of the ink or binder on the elastic roll, the condition of the elastic roll during the cleaning process, the nature of the tested sample, etc

the factors affecting viscosity are: viscosity is closely related to its temperature, concentration of component particles, particle size, etc., but has little relationship with humidity and air pressure. The measurement accuracy and measurement unit of different measurement methods are different and cannot be converted to each other

from the above four points, we can see that there is a great difference between the printing viscosity and the viscosity of ink, but the two are still related. It is mainly manifested in that viscosity is a physical quantity to measure the viscosity of a fluid, and the dynamic viscosity of a fluid is a quantity determined by the inherent physical properties of the fluid itself. Its value is a direct measure of the viscosity of a fluid, and it is also a measure of the ability of a fluid to resist shear deformation in motion. Under the same environmental conditions, high viscosity means high viscosity, and vice versa

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