The important role of ink cleaning agent in printing production
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
In fact, printing companies are very aware of the possible adverse effects of using gasoline and kerosene, but the wide range of sources of gasoline and kerosene, fast drying speed and relatively low price make printing companies unable to refuse. These advantages are particularly prominent compared to the ink cleaning agents available on the market: ink cleaning agents have specific conditions for specific printing presses, blankets, rubber rollers, etc.; special ink cleaning agents are expensive; Nor can it be guaranteed to be completely in time.
Let gasoline and kerosene go to class
The use of gasoline and kerosene cleaning inks has the following disadvantages.
(1) Poor performance
Although the use of gasoline and kerosene for the normal cleaning of rubber rollers and blankets is very convenient and the results are satisfactory, gasoline and kerosene are incapable of water-soluble components such as paper wool, paper powder and gum arabic attached to the rubber rollers. A layer of various impurities is deposited on the surface of the rubber roller, which will close the original capillary pores on the surface of the rubber roller to form a smooth crystal layer, which will change the size of the rubber roller, seriously affect the printing pressure, and the ink transfer performance of the ink roller will decrease. It causes printing problems such as "ink bar" and "flat net hair" during printing. At the same time, a large amount of aromatic compounds contained in gasoline and kerosene will also swell the rubber, affecting printing pressure and printing quality.
(2) Security risks
Gasoline and kerosene are extremely flammable liquids. The flash point (that is, the temperature at which steam explodes in an open flame) is only 20 degrees. If the ventilation facilities in the printing plant are not good, it is easy to cause dangerous situations such as fire accidents. As a result, many printing companies have exploded when workers use gasoline to clean presses.
(3) Unfavorable environmental protection
Gasoline and kerosene contain a large amount of VOC, which is seriously polluted by the environment, does not meet environmental safety standards, and is harmful to employees' health. At the same time, most printing companies will use the method of direct discharge of steam and kerosene that have been cleaned.
All of them are poured into the sewers, and it is unnecessary to say that the pollution of the soil and water quality, while the gasoline floating on the water surface, there is also the danger of explosion in the season when the outdoor temperature is relatively high.
(4) Market elimination
In order to better promote the development of the printing industry, countries around the world have started to develop various regulations and standards for ink cleaning agents (car wash water) since 1995, which mainly include: ink cleaning agents with a flash point below 21 °C. Cannot be used for the cleaning of printing rollers and blankets (such as gasoline); solvents for alkane terpenes (turpentine) containing halogenated groups, n-hexane, imine or acid amines should not be supplied or used; the content of aromatic compounds in solvents It should be less than 0.1%; the content of toluene and xylene in the solvent should be less than 10%.
At the same time, many printer manufacturers, especially high-end printing equipment manufacturers, are rigorously testing and specifying the chemicals used on their printing equipment. As Heidelberg has rigorously tested, there are three types of car wash water that can be used on Heidelberg presses: Bottcherin 60, Superdot and Varn.
In order to undertake international business, some printing companies must pass ISO9001 quality management system certification and ISO14001 environmental management system certification according to requirements. It is naturally prohibited to use gasoline and kerosene as ink cleaning agents.
If in the past, printing companies used gasoline and kerosene as a general choice to expand profits, then in today's increasingly fierce competition in the printing industry, it is indeed a kind of eye-catching use of gasoline and kerosene to clean ink only by considering the material cost at present. This is because it has significantly affected the social and overall economic benefits of the printing industry.
With the large-scale import of high-end printing equipment and the enhancement of the safety and environmental awareness of printing companies, environmentally friendly ink cleaning agents (car wash water) will become the mainstream cleaning solvent for rubber rollers in the future.
Understanding ink cleaners
In fact, the ultimate goal of various ink cleaning agents on the market is to wash away impurities such as inks. In the printing process, many impurities produced by inks, water and substrates can be roughly divided into two categories: one is soluble. , soluble in organic solvents such as ink oils, resins, gelatinous oils, waxes, binders, and acidic and alkaline substances in inks and additives; the other is water soluble, ie soluble in water or Affinity to water, such as gum arabic, casein, paper wool, paper powder, fillers and other inorganic compound impurities and hydrophilic pigments.
Thus, in order to achieve the purpose of cleaning, the cleaning principle is substantially the same, and the composition also generally includes the following types.
(1) Hydrocarbons
In the detergent content of about 50% or more, hydrocarbons are classified into aliphatic hydrocarbons and aromatic hydrocarbons according to their molecular structures, and both have good dissolution effects on inks. Among them, the aliphatic hydrocarbon molecule contains a chain structure of carbon molecules, which cannot be dissolved in water, and is harmless to the human body, the rubber roller and the environment; and the aromatic hydrocarbon molecule contains a cyclic chain structure of carbon molecules, The human nervous system has adverse effects, and long-term use may lead to cancer lesions, which will become a rubber polymer expansion, which also has a certain impact on the rubber roller. Therefore, the international ink cleaning agent related quality standards should be less than 0.1%.
(2) Emulsifier
It can promote the mixing of oil and water and produce emulsification; the general flash point cleaning agent contains emulsifier, which will not cause residual chemicals on the rubber roller and blanket.
(3) Corrosion inhibitor
Since the cleaning agent needs to be mixed with water for cleaning, the anticorrosive agent has a function of preventing moisture corrosion.
The current ink cleaning agent on the market is mainly divided into two parts according to the source: First, it is imported from abroad, and its products basically meet the relevant international quality standards, but the price is expensive. The second is domestically produced, the price is moderate, but the quality is not good. Some products have a low flash point and are prone to fire; some products have high levels of aromatic compounds and are environmentally friendly.
According to the type of technology, ink cleaning agents can also be divided into two types: one is pure solvent type, and needs to be mixed with water when used, but the ratio has an optimal value, and only when this ratio is achieved can the best be achieved. Cleaning effect. In actual production, machine operators often cannot control the ratio of solvent to water well, which not only leads to a lot of waste, prolongs the cleaning time, but also affects the cleaning effect.
The other is an emulsion type ink cleaning agent which has been prepared by mixing the solvent and water in an optimal ratio before the production, and adding an emulsifier, and the droplet size is extremely small, and the ink of the surface of the rubber roller is more easily penetrated. The layer has an excellent cleaning effect and is only 1/4 to 1/5 of the amount of gasoline. This type of car wash water is the development direction of car wash water products in the future.
Generally speaking, the high-quality ink cleaning agent mainly refers to an emulsion type ink cleaning agent composed of two kinds of organic solvents, a rubber anti-aging agent and a surfactant capable of forming a stable water-in-oil type emulsion. It emulsifies the solvent into a W/0 type emulsion system with water by the action of an emulsifier, and can directly replace gasoline for ink cleaning.
The emulsion type car wash water is not flammable, and the storage safety is good, but the transportation volume is large, which increases the use cost. The cleaning performance of the emulsion type car wash water is related to the formulation composition, especially the choice of solvent and active agent has a great relationship. . At the same time, since the emulsion type car wash water is a thermodynamically unstable system, the stability is poor, and it is easy to stratify. Once stratified, it is difficult to deink and affect the use, so the storage period is not too long. At present, some manufacturers have introduced new types of ink cleaning agents, such as micro-emulsion car wash water, without configuration, and the thermodynamic system is stable, making up for the shortage of traditional ink cleaning agents.
In general, ink cleaners are more efficient, energy-saving, environmentally friendly, and safer than gasoline and kerosene. They also have the function of solvent and water. They can remove ink and remove paper and hair. Water-soluble dirt, the amount is relatively small compared with gasoline (cleaning the same ink roller, using ink cleaning agent is only 50% of gasoline), the ink cleaning agent is slow to volatilize, can fully exert its effect, can greatly save the amount, but relative In the case of gasoline, the drying speed is relatively slow.