Inkjet printing is a new non-contact, pressure-free, plate-free printing technology, which can be printed by inputting the information stored in the electronic computer into the inkjet printing equipment. It also has the common feature of plateless digital printing, which can realize the printing of variable information. The ink is sprayed from a fine nozzle to the substrate at a certain speed, and then the image reproduction can be achieved through the interaction between the ink and the substrate.

So what is the size of large-format inkjet printing? Generally speaking, any printing with a format smaller than 850 mm × 1 200 mm belongs to general printing; while printing with a format greater than or equal to 850 mm × 1 200 mm can be called large-format printing. Now large-format inkjet printing products can be seen everywhere, which shows that it is in the golden age of in-depth development and widespread popularity. Inkjet products have been applied to various fields such as large-scale poster printing, short-run art reproductions, body advertisements, etc., and the market is showing a rapid growth trend. The main fields of large-format inkjet printing are as follows.

1. Engineering design industry. Large format printers have the largest market share with computer CAD-aided design and will continue to grow. The application of engineering drawing inkjet mainly represented by CAD has injected vitality into the development of my country's large-format inkjet printing market. Large-format printers are also widely used in the field of GIS, and these users are mostly design units, research institutions, and military departments.

2. Image output field. In this field, the development of large format printers is the fastest. Applications in this field mainly include indoor and outdoor large-format signboard poster printing, advertising, decoration and A3 format advertising. Photo studios also often use high-precision inkjet printers to print photos. Multi-variety and small batch jobs are more suitable for inkjet printing, which can quickly and efficiently solve the market demand for single jobs within 200 copies.

3. Printing industry. In the proofing process in the printing industry, the effect of inkjet printers is very close to the printing effect and is very stable. Many places can use this method to output proofs before printing.

After choosing the large format inkjet printing market, the choice of equipment is a problem. The selection of inkjet printing equipment and ink systems based on product type and output requires careful consideration.

Selection of Ink for Inkjet Printing

There are many types of inks for inkjet printing. Even solvent-based inks are subdivided into dozens of types. According to the nature of the ink, there are mainly three types of inks in the domestic market: UV ink, solvent-based ink, and water-based ink.

As far as the current inkjet printing field is concerned, each of these three types of ink has its own merits and uses. will coexist for a long time for a certain period of time.

1.UV ink

UV inks have a unique curing method, that is, fast curing without penetration and evaporation, and are now widely used in inkjet printing. UV ink has three major characteristics: energy-saving drying, broad printability to substrates (can be printed on almost all materials), and fast curing, which can shorten the subsequent process time.

But UV ink is expensive and the cost is too high, which directly affects the printing price of UV printing equipment. There is also a potential problem with inkjet printing of UV inks, which is to keep the density of the UV light source the same as it comes out of the printhead during the actual curing of the ink, otherwise it will ruin the entire production process. UV inks are not very flexible and will break if they are curled too much; and their prices are also higher than solvent-based inks.

As far as the market is concerned, currently in the field of inkjet printing, it is mainly the printing of wide-format graphics and images with a small number of copies. Because of the small number of prints, the constraints on the ink and the substrate are small, and the advantages of UV ink printing can be exerted. The real advantage of UV inks is their ability to dry instantly under UV light in long runs. Because of this, UV inks have the potential to become the first choice in high-speed inkjet printing, especially as inkjet processes move into lithographic fields such as packaging printing. From the perspective of environmental protection and the adaptability of substrates, UV inks are likely to become the mainstream of the large-format color market in the future.

2. Water-based ink

Water-based ink mainly uses water as a solvent, and has the advantages of stable ink color, high brightness, strong tinting strength, strong post-print adhesion, adjustable drying speed, and strong water resistance. Compared with other printing inks, since water-based inks do not contain volatile toxic organic solvents, there is no adverse effect on the health of operators during the printing process, and no pollution to the atmospheric environment and the printed matter itself. Because the ink is not flammable, it can also eliminate the hidden dangers of flammability and explosion, improve the printing operation environment, and is conducive to safe production.

However, the current water-based inks still have certain technical limitations, and their printing performance and quality cannot meet the standards of solvent-based inks. At present, water-based inks have disadvantages such as not being resistant to alkali, ethanol and water, slow drying, poor gloss, and easy to cause paper shrinkage. This is mainly due to the high surface tension of water, which makes the ink difficult to wet and slow to dry. Ink is difficult to wet and print well on many substrates, and unless the printing equipment is equipped with sufficient drying equipment, the printing speed will be affected accordingly. In addition, the gloss of ink is lower than that of solvent-based ink, which greatly limits the use of ink in applications with high gloss requirements.

In terms of market, water-based inks and paper-based substrates account for the major market share of large-format inkjet printing. Moreover, the digital inkjet printing market shows the following trends: water-based inks tend to change to solvent-based inks, the development of water-based inks will slow down, and solvent-based inks and environmentally friendly solvent-based inks will have further development.

3. Solvent-based ink

In the field of inkjet, solvent-based inks can adapt to various printing materials, and the printing materials used are relatively cheap. In particular, it makes outdoor images have better durability, and its price is lower than that of water-based inks, and it does not require lamination, which improves production efficiency. Solvent-based inkjet presses have opened up billboards, car body advertising and all areas previously impossible for printing.

However, the disadvantage of solvent-based ink is that in the drying process, harmful substances are emitted into the air through the evaporation of the solvent, which affects the indoor and outdoor air quality. Although solvent-based inks dry faster than water-based inks, they do take a certain amount of time.

As far as the market is concerned, not only will solvent-based inks not be eliminated for a long period of time, but the market share will expand rapidly, and it has more advantages to stabilize its position. Relevant ink manufacturers have improved ink formulations and launched environmentally friendly solvent inks and environmentally friendly solvent-based inkjet printers that do not contain harmful substances. The new generation of solvent-based inks will be more perfect and cause less and less damage to the environment.