With the rapid development of China’s commodity economy and the continuous improvement of people’s living standards, people’s demand for packaging of goods is also increasing. At present, the domestic packaging and printing industry is in a period of rapid development. Due to the variety of plastic films and their various properties, various types of printing failures often occur during printing, resulting in various quality problems. How to avoid or reduce the difficulties and quality problems encountered during the printing process, which requires the printing plant to use the corresponding ink when using the substrate, that is to say there is a special ink for a plastic film. General Ink Low Pressure Polyethylene Film Ink Commonly Used Benzene Dissolving Polyamide Resin Special Polyamide Resin Ink Surface Brightener Nitrocellulose Low Viscosity Nitrocellulose Ink Wetting Agent Pigment Low Pressure Polyethylene Special Resin Scratch Resistant Filler Filler Select high-quality paint anti-sticking agent mixed solvent substrate accelerator mixed solvent Source: Ink Information
As we all know, in the surface printing and packaging, polyethylene film (PE) is usually used as the printing material, and polyethylene is more difficult to print material, which is determined by its own nature. Polyethylene is non-polar, chemically stable, and almost insoluble in any solvent. In particular, low-pressure polyethylene film (HDPE) is the most difficult material to print, and it is also the printing substrate that has the most headaches, print defects, and quality problems in many printing companies. Since the low-pressure polyethylene film is a high-density polyethylene formed by low-pressure polymerization, the film is milky white, has a poor surface gloss, and has a low tensile elongation, and is usually printed on the front of a package such as a hand pouch. As a special printing film, low-pressure polyethylene film obviously has to be coated with special ink. Therefore, the ink manufacturer must produce the corresponding low-pressure polyethylene film special ink to adapt the film itself to meet the printing requirements of the printing plant.
We all know that when printing low-pressure polyethylene film requires the ink to achieve the following performance indicators after printing: (1) adhesion fastness: to meet the affinity between the ink and the film. Of course, the degree of treatment of low-pressure polyethylene film must reach a surface tension of 48 dynes/cm or more; (2) abrasion resistance and scratch resistance. This is to ensure that the printed product is affected by a variety of external forces and graphics must be achieved without distortion; (3) drying and anti-blocking. This is due to the fact that the ink is printed in a solvent-vapor-dried manner, which is closely related to the composition of the solvent, the combination of the pigment and the resin, the release of the resin and the pigment to the solvent, the printing machine and the printing conditions, and the post-processing of the printed product after printing. Completely dry the printed product to ensure the anti-blocking effect of the printed product.
In summary, low-pressure polyethylene film as a special film requires special ink to be applied. However, in many printing plants, especially in a very small-scale printing factory, almost no professional training has been received by the printing operation staff, and the technical quality is uneven. Low results in the use of common inks as special inks. As a result, severe printing failures and print quality fail to meet customer requirements or even become obsolete. This kind of thing I have encountered many times. I remember one time, a printing customer in Longgang made a phone call and complained that after the ink was used, the whole piece of ink film fell down, and even if the ink was dropped, the ink fell off. After careful explanation, the original ink was used on low-pressure polyethylene film, which caused such printing problems and print quality problems. Of course, sometimes the ink manufacturer does not really specify whether it is suitable or not suitable for the use of its own products. The use of ambiguous statements in the instructions for use of the product has also misled the printers to use them, causing quality problems in the printed products. So what is the difference between ordinary ink and low pressure polyethylene film ink? Maybe some ink engineering technology peers think that adding some wax powder to the original ordinary ink can solve the problem of the use of low-pressure polyethylene film. Actually not, we might as well compare the general ink with the low-pressure polyethylene film ink material list.
From the table, it is not difficult for us to find that common inks and low-pressure polyethylene films are quite strict in formulation design and material selection. Low-pressure polyethylene film inks are used as special inks in formulation design materials. There is a wide range of product properties, can be used for other conventional film (such as OPP, PE) use requirements, but also to meet the use of low-pressure polyethylene film, its performance, quality, reliability are ordinary ink can not be compared. It can not only meet the adhesion fastness, abrasion resistance, scratch resistance and drying property, but also can satisfy the improvement of glossiness and printing speed. We all know that the printing speed of ordinary inks is generally 10 to 60 meters per minute, while the printing speed of low-pressure polyethylene film inks is 60 to 150 meters per minute, or even higher. Therefore, I do not agree that adding some wax to the original ordinary ink can solve the problem of using low-pressure polyethylene film. Wax powder can solve the anti-friction phenomenon of ink substrate, but this is a temporary solution, ink and the bottom Material adhesive fastness can not be completely solved, and if the amount of wax powder is improperly controlled, improper selection of wax powder will cause the gloss of the ink product to deteriorate. Because the surface glossiness of low-pressure polyethylene film is inherently poor, and the poor glossiness of the ink is printed, the printing product is unsightly, which greatly affects the printing product usage rate, and negatively affects the printing factory and product use customers. Waste of print. In general, the ink product quality of large ink manufacturers is much better than that of small ink manufacturers. From the geographical point of view, the southern ink products are relatively stronger than the north in terms of quality and performance, especially the quality of special inks. . As the ink engineering technicians themselves are holding and the skills are uneven, and the ink market competition continues to intensify, the price of ink needed for raw materials rises again and rises, which also leads to uneven ink quality. It is estimated that this phenomenon will also exist. Can not change within.
At the moment, the world is facing a serious shortage of oil resources, especially environmental protection, and the development and application of economical and environmentally friendly ink that saves resources and protects the environment has become an urgent task for ink engineers and printing professionals. The development and completion of a major mission is not only the responsibility and obligation of the relevant industries to build a conservation-oriented society and a harmonious society, but also an objective demand for sustainable development of related industries. The development of ink has become the dominant direction in the future development of ink. In particular, research and development and realization of special-purpose thin-film use of water-based special ink, is all ink engineers and technicians to discuss and face a major issue!
Talking about low pressure polyethylene film ink