Because there are many ways in printing, such as overlapping (contrast), cover color, solid color blocks, small print and so on. The number of screen lines, ink on the rubber roller or ink on the doctor blade, whether it is printed on kraft paper, white paper, or coated paper has different modulation requirements for ink.
The standards given here can only be used as a reference.
Inspection items: 1. Ink viscosity 2. Ink pH 3. Ink hue
Inspection tools: (1) ZAHN No. 4 cup (2) pH measuring instrument (3) color spreader or acrylic blade (4) test paper
Inspection standards: 1. Ink viscosity: 20 ~ 23 seconds (Zahn No. 4 cup), (56 ~ 76 seconds DIN No. 4 cup); 2. Ink pH value: 8.3 ~ 8.7; 3. Ink color density: develop ink color Comparing with the standard color after the appliance is evenly coated; 4. Colorless ink: viscosity 11 ~ 13 seconds pH 8.5
Ink use standard (standard after use)
General kraft paper
1. Squeegee method: general or halftone dot printing ink viscosity DIN4 cup 18 ~ 26 seconds (9-12 seconds Zahn 4 cup), ink pH value: 8.3-8.5
2. Squeegee method: Full-print printing ink viscosity DIN4 cup 22 ~ 30 seconds (10-14 seconds Zahn cup 4), ink pH value: 8.3-8.7
3. Ink transfer method of rubber roller and anilox roller combination: ink viscosity Zahn No. 4 cup 09 ~ 14 seconds (DIN4 No. cup 18 ~ 30 seconds), ink pH: 7.9-8.2
1. Squeegee method: general or halftone dot printing ink viscosity DIN4 cup 20 ~ 28 seconds, ink pH value: 9 ~ 9.5
2. Squeegee method: full-print printing ink viscosity DIN4 cup 20 ~ 28 seconds, ink pH value: 9 ~ 9.5
3. Ink transfer method of rubber roller and anilox roller combination: ink viscosity ZAHN No. 4 cup for 10-15 seconds, ink pH value: 8.2 ~ 9.5
Several aspects of the note room are needed for multi-color printing:
1. The pH value of the overlapping color ink is higher than the second color, and the pH value decreases according to the color continuity.
2. The viscosity of the overlapping color ink is lower than the second color.
3. The ink transfer method of the rubber roller and the anilox roller is more affected by the printing speed than the doctor blade method.
4. After the machine is installed, the ink viscosity and ink pH are adjusted according to the customer's requirements for hue and overlapping color.
5. When the anilox roller has high mesh and low ink content, increase the pH value according to the actual situation.
6. High pH value on the surface of coated paper should also pay attention to controlling the pH value of ink
Explain a noun: surface tension
Surface tension is a measure of transfer ability. Matter is inherently inherent in tension, with daye as its unit, and measurement also has a dedicated dyne pen.
Briefly explain what is the surface tension: we first fill the glass with water, and then put a coin into the cup, at this time the liquid level will rise above the edge of the cup without water overflowing. This is the surface tension.
The surface tension of water is about 77 dyne. Fluid will not flow from this surface to another surface unless the new surface tension is greater than the surface tension to leave the surface, for example water will not flow from this cup to another cup by itself.
The surface tension of corrugated cardboard is 40-55 dyne, printing plate is 28-42 dyne, anilox roller is 33-72 dyne, rubber roller or doctor blade is 22-38 dyne, and ink is 23- 42 dyne.
The ink will be transferred to the anilox roller to the printing plate, and then transferred from the printing plate to the face paper. Both move from low surface tension to high surface tension.
The carton factory does not need to worry about surface tension, and the ink supplier only needs to pay attention to the situation when registering.