Analysis and Research on the influencing factors o

Analysis and Research on the influencing factors of the dispersion effect of water-based ink (II)

2.1.2 the dispersion base resin requires operators to carefully optimize the dust removal and cleaning of the equipment

use the flow point technology to investigate the flow of resin (R1, R2, R3, R4, R5) dispersed carbon black P1, as shown in Figure 1. The results show that the two flow point curves R1 and R3 with different shapes have obvious flow points, which are suitable for dispersing carbon black P1. R2, R4 and R5 may have good performance, but they are not suitable for dispersing carbon black P1. It can be seen from Figure 1 that the flow point is about 20% of the mass fraction of the base material

2.1.3 influence of abrasive composition on dispersion effect

on the basis of determining the flow point, R1 is selected as the dispersion resin and P1 as the dispersion object. In order to reduce the interference factors in the dispersion test, especially the positive and negative effects of surfactants on the grinding effect, so that energy saving and material saving have become the focus of the extrusion processing industry, polymer defoamer A5 with good processability was selected in the experiment, because the polymer defoamer has good miscibility with the system, and will not produce stable foam and cause shrinkage defects. In addition, using the above flow point method, the color base ratio suitable for dispersing carbon black P1 is 3/1~2/1. On the basis of experiments, a comparative experimental formula was designed to investigate the influence of abrasive composition on the dispersion effect (dispersion speed, hiding power, coloring power and 60 ℃ gloss). The comparative experimental formula is listed in Table 1

Table 1 abrasive formula

Figure 2 reflects the effects of high pigment and low pigment mass fraction formula on ink dispersion fineness, hiding power, coloring power and 60 ℃ gloss. Obviously, the dispersion performance of ink is closely related to the composition of abrasive

Figure 2 Effect of grinding abrasive formula on ink dispersion performance

(1) as shown in Figure 2a, the dispersion fineness decreases with the extension of dispersion time, and the lower pigment filling amount cannot effectively disperse the last "coarse particles" in grinding abrasive

(2) as shown in Figure 2B, with the dispersion, the hiding power of the two formulas after dispersion is significantly improved, but the hiding power of the high pigment content formula after dispersion is significantly higher than that of the low pigment content formula

(3) the coloring power of the formula with high pigment content after dispersion is significantly higher than that of the formula with low pigment content in the process of dispersion, but after grinding and a certain fineness, the coloring power is relatively close. This shows that the coloring power of pigments dispersed to a certain fineness is mainly related to the dispersion resin, as shown in Figure 2C

(4) it can be seen from figure 2D that the difference between the two on gloss is small, which is close to the limit of experimental error and the difference caused by small changes in pigment dispersion

(to be continued)