"Cellular" Technology to Improve Gravure Printing Effect (I)

In today's gravure printing industry, 95% of manufacturers use conventional mechanically engraved ink rollers to print high quality image products (Braswell, 2000). Can this situation improve? Of course, there is a way to improve the printing quality by improving the ink roller. In this paper, five different sculpting ink rollers were experimentally studied. Conventional Diamond needles and Honeycomb Diamonds were used to engrave six different ink rollers, and the ink rollers were different. Ink, different substrates, and printing effects under different engraving conditions were tested. The results show that "cellular technology" helps to improve the quality of printed products.

The basic theory of the HC (hexagonal diamond) needle has been around for 7 years. In the United States, the intaglio printing industry consumes 8 to 10% of the total diamonds on average. The HC sculpting needle is actually not mysterious. It differs from the CD (normal diamond) sculpting pin in that its needle tip is flat and forms a flat tip. It can be carved in the hexagonal honeycomb flat bottomed ink hole. Figure 1 is a schematic diagram of a HC ink hole with a 120 degree engraved needle.

As shown in the figure, the volume of the ink holes carved with HC diamond is reduced by about one-third. However, in theory, HC ink holes release more ink than conventional diamond ink holes. Existing research results show that increasing the ink transfer speed of the ink roller helps to improve the printing quality and reduce the ink consumption. If this is combined with the flat bottom of the HC ink hole, we have reason to believe that the HC engraving ink hole is a better method between laser engraving and electromechanical engraving. Straight HC stylus needles of any size or angle are now available on the market, and most deliveries guarantee that their product tolerances are limited to ±5 μm.

Experimental purpose <br> The data provided in this paper aims to evaluate the effect of HC ink roller on the color density, dot reproduction, tone reproduction, ink weight, and printing brilliance of printed materials on different substrates.

Experimental Protocol <br> This experiment uses six different ink rollers carved by RJR Packaging of Winton-Salem, North Carolina to evaluate the impact of HC Diamond engraving ink holes (flat edges) on printing under different conditions. :

Engraving method I
Using an ink roller, the engraving conditions are shown in Table 1. The ink roller test was RJRP's GMS printer. The substrates were Mylar (5mill) and 54 pound CIS paper. A standard nitrocellulose ink with an ink viscosity of 23.

Table 1 Engraving conditions (I)
Ink roller diameter Diameter of wire mesh Diameter of diamond point Tip width of ink hole
1 8.675" 188 39 110 25μm 0 10 153
1 8.675" 188 39 110 0μm 0 10 153

Engraving method II
Using an ink roller, the engraving conditions are shown in Table 2. The ink roller test was an RJRP GMS printer using a 54-pound CIS paper and a standard nitrocellulose ink with a viscosity of 23.

Table 2 Engraving conditions (II)
Ink Roller Diameter Mesh Compression Diamond Angle Flatness Measure Hole Wall Hole Wall
2 8.675" 188 39 110 5μm 0 10 153
2 8.675" 188 39 110 15μm 0 10 153
2 8.675" 188 39 110 25μm 0 10 153

Engraving method III
Using two ink rollers, the engraving conditions are shown in Table 3. The test was performed on RJRP's 10-color Rotomec printer using 48 GA PET material and a standard polystyrene ink with a viscosity of 17.

Table 3 Engraving conditions (III)
Ink roller diameter Diameter of wire mesh Diameter of diamond point Tip width of ink hole
3 10.505” 188 40 115 0μm 0 9 155
4 10.505” 188 40 115 25μm 0 9 155

Engraving method IV
Using an ink roller, the engraving conditions are shown in Table 4. On RJRP's 10-color Rotomec press, 26 pounds of clay-coated, standard nitrocellulose ink with a viscosity of 17 was used.

Table 4 engraving conditions (IV)
Ink roller diameter Diameter of wire mesh Diameter of diamond point Tip width of ink hole
5 9.9475” 188 40 110 5μm 0 10 155
5 9.9475” 188 40 110 15μm 0 10 155
6 9.9475” 188 40 110 25μm 0 10 155

Engraving method V
Using an ink roller, the engraving conditions are shown in Table 4. On RJRP's 4-color Cerutti Press, Tipping Paper and Standard Adhesive Ink.

Table 5 engraving conditions (V)
Ink roller diameter Diameter of wire mesh Diameter of diamond point Tip width of ink hole
5 11.615” 14 40 110 25 μm 32 14 21