Domestic flexible packaging gravure ink

In the past two to three years, China's flexible packaging market put forward two major requirements for ink suppliers:

1. Generalization: At present, the ink used in the soft packaging industry is basically an ink corresponding to a substrate, and the ink between various substrates cannot be used universally, resulting in an increase in inventory types, difficulty in management, and an increase in on-site operation procedures. Residual ink is difficult to digest and so on. In response to this situation, the ink industry has proposed two solutions:

A, using an ink should correspond to a variety of substrates. This is a very difficult operation. At present, we have made some progress, but there are two major difficulties: the composite strength of some substrates is still not satisfactory, and the cost is high and the rigidity is high;

B. The use of universal colorants with different binders, plus on-site ink distribution systems, can also meet the general requirements of flexible packaging companies. At present, it is not very difficult on the technical level. If there is a large soft packer working together, the cost barriers will be smaller and the promotion may be faster.

Another benefit of adopting a universal ink system is that color can be standardized.

2. Environmental protection: With the increasing awareness of environmental protection and stricter legal regulations, more and more attention has been paid to the safety and hygiene of materials. The requirements of the gravure ink industry for environmental protection are currently focused on the following aspects:

A, existing products reduce residue: This type of work is mainly reflected in BOPP special ink. The main countermeasures adopted are: Use solvent-releasing binders as much as possible, add additives to facilitate volatilization of aromatic hydrocarbons, etc. The best result currently is that the amount of printed matter is about 1 mg/m 2 . However, since the binder system itself determines that aromatic hydrocarbons cannot be eradicated from the system, it is an ink that is bound to be eliminated from an environmental perspective.

B, removal of aromatic hydrocarbons: the so-called benzene-free, because many large food companies in Europe and America internal control quality standards expressly stipulate that all packaging materials must not be added to aromatic materials. In order to meet this requirement, benzene-free ink came into being. This kind of ink is theoretically free of aromatic hydrocarbon solvents, but due to the storage, transportation of raw materials, manufacturing process and the use process will be more or less mixed with a small amount of aromatic hydrocarbon solvents, so the "no benzene" It should be understood that the content of aromatics in the system is <=1%. In addition, it should be pointed out that due to the normal printing speed, MIBK (methyl isobutyl ketone) is added to remove aromatic hydrocarbons from the ink to adjust the volatilization rate of the ink. At present, there is no clear regulation for the solvent. no. Therefore, flexible packaging suppliers must communicate with customers before use, whether it can accept a certain percentage of residual, because the smell of this solvent is relatively strong. It is also worth pointing out that the printability of this kind of ink is somewhat poor.

C. Alcohol Solvent System: Due to stricter residue requirements, major companies in the ink industry have also introduced alcohol-soluble inks. These inks do not contain aromatic hydrocarbons, nor do they contain ketone solvents. They contain only esters and alcohol solvents. They are excellent in terms of environmental protection, but the evaporation speed is difficult to adjust, and printability is much poorer. The reproduction of the corresponding exquisite patterns is much more difficult, and at the same time, due to the small amount of use, the production capacity cannot be achieved and the cost is high.

D. Water-based system: Water is an ideal environment-friendly solvent, but water-based inks are currently used only in paper (packaging and publishing) and have been developed for non-absorbing, low surface tension substrates such as films. Market-acceptable water-based inks have a long way to go, such as the performance of the ink itself, the thermal stability of the substrate, and the fit of the equipment. But it can be pursued as a mid-term goal.

E, solvent-free system: One of these inks is a hot-melt type ink. Currently, there are laboratory results. However, to enter the market, a lot of work must be done on raw material synthesis, manufacturing processes, storage methods, and application equipment. Of course, in theory, UV gravure can also be included, but there have been no reports of UV gravure printing applications.

Whether it is generalization or environmental protection, it is only at the initial stage in China. In order to gain something, the upstream and downstream colleagues of the packaging industry need to work together.

Source: 21st Century Fine Chemicals Network