The hottest special ink and its application skills

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Special ink and its application skills (Part 2)

anhydrous ink

the recent development of anhydrous printing ink has made it have more characteristics of traditional offset printing ink. However, most anhydrous inks have high viscosity and thick texture. It is not easy to spread smoothly when it is transferred in the ink roller, and it will harden or dry on the surface of the ink roller. The best anhydrous inks are those with a wide temperature range - between 72 and 92h - and have the ability to stay dry when exposed

skill: if an anhydrous ink loses its viscosity due to running for too long, reducing the temperature will enhance the viscosity of the ink itself; If the ink hardens after staying on the ink roller for a period of time, raising the temperature will improve its fluidity

non traditional ink and recycled paper

traditional quick drying ink is very suitable for front printing of paper (or non recycled paper), but the same ink often has problems when printing on recycled paper, especially when the ink volume is small (compressive strength/flexural strength or small surface). This is because light ink will make the ink stay on the ink roller longer than when printing thick ink or large surface. When the ink is waiting to be deposited on the paper, the ink on the ink roller has a tendency to lose solvent and increase viscosity. This high viscosity will pull out weak fibers in recycled paper and affect the normal progress of printing

skill: vegetable oil inks have lower viscosity than high solvent based inks. They also have better ink roller stability than high solvent inks in terms of raw materials, large investment by industrial enterprises and high capital consumption, which makes them maintain low viscosity throughout the printing process. This ink stability is reflected in the cost of slow printing, which means that it takes longer time in reprint printing. However, this is a reasonable deal for achieving high-quality printed matter on recycled paper

choose a suitable fountain solution

inks with non-standard substrates are often incompatible with a certain type of fountain solution. Low VOC or vegetable oil based inks are dried by oxidation. This means that the equipment using this kind of ink can be set up slowly and dry for a long time. Using alcohol fountain solution can speed up the drying speed, but avoid using nonvolatile wetting agents, such as ethylene glycol

for petroleum based inks, because petroleum is easily absorbed by paper, the machine can run faster and the drying time is shorter. This kind of ink is suitable for using alcohol substitute as fountain solution

metal inks build trust. All fountain solutions containing 10% to 15% isopropanol can be used, which are more appropriate. It is recommended to use a fountain solution with a pH value between 6.0 and 6.5, which will make the printing of metal ink cleaner and brighter. One half ounce of fountain activator should be added per gallon

all fountain solutions are suitable for opaque inks. Add 15% water-resistant inking oil to opaque inks with any fountain solution to improve fluidity and transferability and prevent "spots". In order to ensure the best effect, the pH value of the fountain solution should be kept between 4.5 and 5.0 during the printing process

fluorescent inks usually have no special fountain solution, but alcohol fountain solution has a better effect on metal plates. Fluorescent ink printing requires a large amount of ink. It is necessary to add 20% alcohol to the fountain solution to get a better density value. Such a mixture can allow a large amount of water to volatilize, and the oil layer is thick

in the anhydrous printing process, the existing construction technology of ink is used, resulting in too many plate seams and the balance of temperature replacing the balance of water and ink, so there is no need to add fountain solution

skill: adding less than one ounce of ordinary pure ammonia (to ensure that it does not contain detergent substances) to each gallon of fountain solution will increase the pH value of the buffer

source: printing chemicals

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