The production of PET high-end printed plastic boxes has the following requirements for materials:

PET materials usually have good hardness and brittleness, no purification, no crystal points, high transparency, good brightness, and strong impact resistance. Generally speaking, the thickness of PET plastic boxes is between 0.10-0.60mm. When making PET high-end printed plastic boxes, PET materials are required to be environmentally friendly and non-toxic to meet internationally recognized environmental standards. At the same time, in order to ensure the printing effect and product quality, the surface of the material must have good smoothness and uniformity to ensure that the printing color is bright, the pattern is clear, there are no ink spots, fading and other problems.
During the production process, the PET material needs to be coated and cut. The incoming material is usually in rolls and needs to be cut into pieces according to the size of the plastic box. The coating is to protect the finished plastic box from being rubbed or scratched during the production and transportation process. In addition, the material needs to be pre-treated on the surface, such as corona treatment or surface coating, to improve the surface energy or wetting ability of the material and ensure the firmness of the ink and ribbon. The base color of PET materials is often whitish, but its base color can be artificially controlled.
In short, the production of PET high-end printed plastic boxes has strict requirements on the selection and processing of materials to ensure the high quality and aesthetics of the final product.

Characteristics of PET materials

PET materials have many characteristics. First, it has excellent wear and friction resistance and dimensional stability, which enables the manufactured products to maintain good shape and performance in long-term use. Its electrical insulation is excellent, less affected by temperature, and can stably play an insulating role under different temperature conditions. In addition, bottles made of PET have the advantages of high strength, good transparency, non-toxicity, impermeability, light weight, and high production efficiency, so they are widely used in the packaging field. PBT has a similar molecular chain structure to PET, and most of its properties are the same, but the main chain of PBT molecules is longer, the molecules are more flexible, and the processing performance is better. PET is a highly crystalline polymer with a milky white or light yellow color and a smooth and shiny surface. It has good creep resistance, fatigue resistance, and friction resistance, low wear and high hardness, and has the greatest toughness among thermoplastics. However, PET also has some shortcomings, such as poor corona resistance, inability to hot water immersion and alkali, high glass transition temperature of resin, slow crystallization speed, long molding and forming cycle, large molding shrinkage, poor dimensional stability, brittle crystallization, low heat resistance, etc. Through the improvement of nucleating agent, crystallizing agent and glass fiber reinforcement, PET has the properties of PBT, high heat deformation temperature and long-term use temperature, suitable for preparing soldered electronic and electrical parts, high bending strength and elastic modulus, high cost performance, etc.

PET plastic box thickness requirements

Generally speaking, the thickness requirements of PET plastic boxes vary depending on the purpose. There are many options for the thickness of common PET plastic boxes, such as PVC, PET plastic boxes are generally between 0.10-0.60mm, and PP plastic boxes are generally between 0.10-0.80mm. It should be noted that if the plastic box material is too thick, the appearance of the plastic box will look dull. For example, in some product packaging with high requirements for appearance, thinner PET plastic boxes may be selected to show the exquisiteness of the product; in the case of a certain load-bearing capacity, slightly thicker PET plastic boxes may be selected, but they also need to be controlled within a reasonable range to avoid affecting the appearance and user experience.

Environmental standards for PET materials

PET materials have certain standards for environmental protection. The national standard QB2357-1998 stipulates the relevant standards for polyester (PET) non-carbonated beverage bottles, QBT1868-2004 stipulates the standards for polyethylene terephthalate (PET) carbonated beverage bottles, and QBT2665-2004 involves the standards for polyethylene terephthalate (PET) bottles for hot filling. There are no national or industry standards for non-beverage PET bottles for edible oil, vinegar, soy sauce, etc., and enterprise standards must be filed with the local quality supervision bureau (usually provincial). In addition, for the definition of “beverage”, please refer to GB10789-2007 General Rules for Beverages.

Material requirements to ensure printing effect

To ensure good printing effect, the following requirements are imposed on materials. First, the paper of the printing material must meet certain standards. For example, when printing newspapers, in order to obtain better results, coated paper is usually selected because this paper has good toughness, and certain requirements are also imposed on color and smoothness, which can avoid tearing during the flipping process. Secondly, the selected ink should be able to solidify quickly to avoid trouble caused by the ink not drying during the circulation of newspapers. In addition, during the printing process, it is necessary to ensure that the materials meet the standardized process during the operation, strictly limit the work standards of each employee, ensure that the printing quality of each process is qualified, and cooperate well with each other to ensure smooth printing, so as to obtain better printing effects.

PET material background color regulation

The background color regulation of PET sheets is an issue that needs attention. Generally speaking, if the color is bluish when transparent PET is produced, it may be caused by a variety of reasons. If the raw material is not completely dry, it should be thoroughly dried before production; if the raw material is fully dried but still bluish, a little yellow can be added for color adjustment. In addition, excessive drying of raw materials and excessively high production temperatures may also cause the PET sheets to be produced yellowish. At this time, it is necessary to reduce the dryness of the PET raw materials or reduce the PET production temperature. It should be noted that different production processes and equipment may affect the control of the base color, so they need to be adjusted and optimized according to the actual situation.

Conclusion: Based on the above, the requirements for materials in the production of PET high-end printed plastic boxes are multifaceted. PET materials themselves have certain characteristics, such as wear resistance, dimensional stability, and good electrical insulation. When making plastic boxes, the thickness of the plastic box should be considered to ensure a balance between appearance and load-bearing capacity. At the same time, the environmental protection standards of PET materials need to comply with relevant regulations. In order to ensure the printing effect, there are specific requirements for materials such as paper and ink. In terms of the control of the base color of PET materials, attention should be paid to factors such as dryness, production temperature, and color matching. Only by considering these aspects comprehensively can a PET high-end printed plastic box that meets the requirements be produced.