Development status of the most popular waterless o

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Development status of anhydrous offset printing ink dishes

environmental friendly anhydrous offset printing ink

offset lithography is a relatively complex printing method. It eliminates the fountain solution, improves the quality of printing materials, improves production efficiency, and is more environmentally friendly. However, there is still a lot of ink formulation work to be done to develop special anhydrous offset printing ink to match the surface characteristics of new plates and successfully realize the transmission, stripping and transfer of ink, We need to continue to explore this new field that is gradually developing, environmental friendly anhydrous offset printing ink

1, development status of anhydrous offset printing ink dishes

compared with the first and second generation, the third generation of anhydrous offset printing has used low penetration anhydrous offset printing ink. In addition, the printed matter is no longer thick ink film printing, but thin film printing like ordinary offset printing. The nature and stackability of other printing operations are also the same as ordinary offset printing. The improvement of sheet fed and web printing machines in terms of adjustable printing speed and automation is endless, but the impact of printing speed on Printing suitability is far beyond the expectation of printing machine designers, especially on ink transfer

① dry-o-colorartis: dry-o-colorartis, which was launched five years ago, has improved the ink's transferability, stability, powder fixation and post-processing adaptability on the basis of maintaining the gloss and dirt resistance of the product, and is more suitable for the requirements of high-speed, multi-color sheet fed anhydrous offset printing machines

a, design idea. After achieving the low drillability and low drillability required by high-speed printing, special additives must be used in order to further control the dirt resistance; To maintain the drillability and drillability, we can only further improve the fluidity of the ink to improve the transferability of the ink. The specific method is: to improve the dispersion of pigments. Use highly soluble resin binders: to maintain dirt resistance. Non aromatic solvents that can quickly diffuse the lipophilic resin of the printing plate and the silicon layer of the non image part should be used, and new binders should be developed

b, ink characteristics. Under the condition that the drillability and drillability of the ink are almost the same as those of the original product, the fluidity of the ink is increased by about 15%, and the transferability of the ink is increased by about 10%

c market evaluation. Good gloss, fast powder fixation: close to the quality of water offset printing: it has the printing suitability equivalent to that of ordinary offset printing ink; The covering power of ink has also been improved, and a few users put forward their opinions: the twisting performance of ink has been reduced by about 5%; Color reproducibility is not completely consistent with water printing; Field density is slightly inferior to water offset printing

② thermosetting anhydrous offset printing ink for high-speed rotary offset printing machine: compared with sheet fed printing, the printing speed of Web rotary offset printing is increased by about 2 times, and the requirements for ink fluidity are higher and the requirements for drillability are slightly lower. Adopt and. Ry-o-color peel strength tester aris the same resin design method is also suitable for rotating waterless offset printing ink, that is, using a binder that changes the fluidity of the ink without reducing ject dirt resistance), so that the ink can obtain good transferability in high-speed printing. In addition, because the material of this part is a metal brush

2, research on anhydrous offset printing oil

anhydrous offset printing plate is composed of lipophilic resin layer and oil repellent silicone layer. For anhydrous offset printing ink, the most important properties are dirt resistance, ink transfer and ink inkability. Key points for the development of anhydrous offset printing ink:

① develop towards low drillability and high fluidity. Due to the improvement of matte coated paper and recycled paper and the increase of paper consumption, in order to improve production efficiency, the printing speed continues to improve, followed by the occurrence of paper roughening and plate stacking. Anhydrous offset printing does not use fountain solution. Compared with water offset printing, the viscosity of ink on the paper is higher and it is more prone to galling and pile failure. Therefore, the low drillability and high fluidity of ink are the key to ink technology innovation

the use of high polymer, high solubility new resin plays an effective role in obtaining low drillability and fluidity inks, which can be crosslinked by low drillability resin without compromising the fluidity. In the process of resin literary couplets, polymer like structures are produced between polymers, and the internal cohesion increases, resulting in increased viscosity. For example, aluminum chelate gelling agents will lead to the loss of ink fluidity. Therefore, a heating polymer resin composed of rosin modified phenolic resin and Qi Lang compound with long molecular chain is proposed to make the resin quantitative and plastic, so as to obtain a resin binder with low drillability

② improve the dirt resistance: the dirt resistance is expressed in CT, which is related to the drillability and fluidity of the ink. It is directly proportional to the drillability and fluidity, and inversely proportional to the fluidity. Therefore, it is difficult to design high CT ink with the ink technology of low drillability, low drillability and good fluidity (off speed printing). Waterless offset printing should have dirt resistance while achieving low drillability. Therefore, the key problem in the formulation design of waterless offset printing ink is how to prevent the printing plate from dirt. Generally speaking. Dirt resistance is closely related to ink drillability, solvent used, printing field density, printing machine structure, printing speed and other conditions

③ improve the delicacy: soybean oil ink 6. The connecting rod driven by the connecting cam of electromechanical and reducer is an environmental protection ink that replaces the organic solvent ink. Compared with the high curing oil dish or anhydrous offset printing ink, its curing speed is slower, but from the practical results, the ink has good transferability, the powder lining of the field part is good, and the bright part has uniform color. The common offset printing ink penetrates quickly due to solvent after reaching the paper. In the part close to the paper, the dish will be broken, while the soybean oil and ink will be more close to the side of the blanket because of its slow penetration, which is equivalent to transferring the thicker inner film to the paper, so the transfer amount of the oil dish will be increased

④ improve ink transferability: there is a certain relationship between ink characteristics and color development. That is, the higher the ink drillability and drillability, the lower the color development; The smaller the fluidity, the lower the color development. In order to obtain high color development, it is necessary to improve the transferability of the ink, so the ink must have low drillability, low drillability and high fluidity

it is difficult to give consideration to both dirt resistance and ink transfer. How to keep a balance is the key to the design of waterless offset ink

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