Plastic box is a kind of packaging box, refers to PPC, PVC, PET / APET as a material, after printing, die-cutting, sticking box and a series of processes processed product packaging box. Compared with other cartons and other packaging, the plastic box has the advantages of environmental protection, non-toxicity, high transparency, and more intuitive display of the packaged products, which can effectively improve the product packaging grade. PP, PET, APET materials are environmentally friendly, non-toxic, except PVC.
(1), plastic box classification
Classified by material: PP plastic box, PVC plastic box, PET plastic box, etc.
Classified by box type: cylinder plastic box, square plastic box, special-shaped plastic box, soft plastic box, beer, etc.
(2) Production process
1. Plate making: Nowadays, CTP plate making is commonly used in plastic box making.
2. Selection of materials: General plastic box packaging uses PET, PVC, PP and other materials, PVC, PET thickness are mostly ranging from 0.10-0.0.55, PP can be as thick as 0.75MM, because the material is too thick The plastic box is too hard and the appearance looks very dull.
3, printing: outside the plastic box is not printed, at most only silk screen, because the plastic box is the outer box, so the printing process is very high, the most taboo color differences, ink spots, fade these aesthetic shortcomings.
4, surface treatment: plastic box packaging usually do surface treatment, the common is the light glue, too dumb glue, over uv, light oil, over matte oil. It is also what we call the offset printing.
5, beer (die cutting): beer is a more important part of the printing process, to be quasi-must be a model to be accurate, if the beer is not allowed, beer bias, beer, which will continue to seriously affect the follow-up processing.
6, film: the general print is the first beer after the film, but the plastic box is the first beer after the film, one is afraid of getting flowers packaging, and the other is the plastic box pay attention to the overall appearance, plastic box membrane material must be manual Production, in order to achieve a certain degree of beauty.
7. Sticky box: after the laminating machine, need to go through the sticky box process (automatic sticky box, artificial sticky box), sticky box need to pay attention to the choice of glue, different materials require different types of glue.
The properties of the plastic box material PVC, PTE, PP determine the quality of printing ink color, only good performance raw materials can obtain better printing product color 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 the process conditions, reasonably selecting 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 color rendering effect
Smoothness is a technical index for evaluating the degree of surface roughness of a plastic box, and is a physical quantity indicating that the surface of the plastic box is flat, smooth, and uniform, that is, under a certain vacuum condition, a certain volume of air is tested under certain pressure from a plastic box. The time required to flow between the surface and the smooth glass surface is measured in seconds. The higher the second, the better the smoothness of the plastic 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 at the time of printing, the more sufficient the ink layer transfer on the layout (relief) or the blanket, and the better the coloring effect of the printed product. On the contrary, the poor smoothness of the plastic box raw materials, ink transfer is not uniform, and insufficient, and the raw material surface of the ink permeability, coloring effect is also poor, often easy to make ink prints hair, fade. Therefore, for products with fine print, the finer the network cable and the smaller the diameter of the dot, the more should be printed with a smooth box of plastic material, so that the original can be reproduced well.
2. The relationship between gloss and color rendering of plastic box
The gloss of the plastic box refers to the degree of specular reflection on the surface of the plastic box and is expressed as a percentage. The higher the gloss of the plastic box is, the more mirror-like the light reflected on the surface of the plastic box, the brighter the appearance characteristics. 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. High gloss plastic box raw materials, printing ink color is also more vivid, ink visual effect is also good. It can be said that the smoother the raw material of the plastic box, the higher the gloss and the higher the glossiness of the printed product. There is a close relationship between the glossiness and the smoothness of the raw material of the plastic box, but the glossiness is not smoothness. The glossy surface of the plastic box material is not necessarily a smooth surface. From the perspective of the glossiness of the raw material of the plastic box, it is of great practical significance to select suitable plastic box raw materials for printing according to the characteristics of the prints. If the layout of the text-based books and texts, should choose the general paper gloss, so as not to reflect, so that the eyes do not look tired for a long time. The printing of the plate-based layout, should use high-gloss PVC, PET, PP materials, so that the ink is uniform, thick, bright and pleasing.
(4) Application range
As the plastic box is relatively expensive compared to traditional carton packaging, with the national environmental protection and green requirements for the printing industry. The advantages of plastic boxes are increasingly apparent. Currently the most widely used plastic box is the baby industry, cosmetics, digital products and so on.