The performance of the plastic box raw materials PVC, PTE, PP determines the quality of the printing ink color, only the raw materials with good performance can get better printing color rendering effect. Therefore, a correct understanding of the relationship between the performance of the plastic box and the color of the printed product, according to the characteristics of the printed product and process conditions, the reasonable selection of high-quality raw materials for printing, has important practical significance for improving product quality.

1. The relationship between the smoothness of the plastic box and the coloring effect

Smoothness is a technical index for evaluating the degree of unevenness on the surface of the plastic box. It is a physical quantity indicating the smoothness, smoothness and uniformity of the surface of the plastic box. That is, under a certain vacuum condition, a certain volume of air is tested from a plastic box under a certain pressure. The time it takes to flow between the surface and the smooth glass surface is measured in seconds. The higher the number of seconds, the better the smoothness of the box. The better the smoothness of the plastic box, the more uniform and complete the contact between the surface of the material and the printing plate during printing, the more the ink layer on the surface (the relief) or the blanket is transferred, and the better the color rendering effect of the printed product. On the contrary, the raw material of the plastic box with poor smoothness, the ink transfer is uneven, insufficient, and the surface of the raw material has a strong permeability to the ink amount, and the color rendering effect is also poor, and it is easy to make the printed ink color and light. Therefore, the finer printed products, the finer the network cable and the smaller the diameter of the dot, the more the raw material should be printed with a smooth plastic box, so that the original can be reproducible.

2, the relationship between the gloss of the plastic box and the color effect

The gloss of the plastic box refers to the degree of specular reflection on the surface of the plastic box, expressed as a percentage. The higher the gloss of the plastic box, the more the surface can reflect light like a mirror, and the brighter the appearance. In fact, in addition to the specular reflection on the surface of the plastic box, there is diffuse reflection, which causes the gloss of the plastic box to decrease. The high-gloss plastic box raw materials, the brighter the printed ink color, and the visual effect of the ink color. It can be said that the smoother the raw material of the plastic box, the higher the gloss, and the higher the gloss of the printed product. The gloss and smoothness of the raw material of the plastic box are closely related, but the gloss is not smooth. The shiny surface of the plastic box raw material is not necessarily a smooth surface. From the point of view of the gloss characteristics of the raw materials of the plastic box, it is very practical to select the appropriate plastic box raw materials for printing according to the characteristics of the printing. For example, if the layout is text-based, the paper with gloss should be used to avoid reflection, so that the eyes will not be tired for a long time. For the printing of the plate-based layout, it is advisable to use PVC, PET and PP materials with high gloss to make the printed ink color uniform, thick and bright.