Do not ignore ink cleaners

As we all know, the main body of the world printing industry is offset printing. Offset printing ink is transferred to the substrate through ink rollers, blankets, etc. The ink roller and blanket are durable goods. To ensure its normal operation, regular cleaning and maintenance are very important. This includes 3 kinds of cleaning: routine cleaning after printing every day; changing color before cleaning ink; regular thorough maintenance cleaning. In this sense, ink cleaning is a very important task for printing companies. In addition, ink cleaning agents are very large quantities of printing consumables. According to management, printing companies should attach great importance to the procurement and selection of ink cleaning agents, but the current situation Yes, a large number of printing companies partially or completely use gasoline and kerosene as ink cleaning agents. A survey shows that even in Beijing where the printing industry is relatively developed, almost none of the printing companies totally abolishes the use of gasoline and kerosene to clean printing presses.

In fact, printing companies are very clear about the possible adverse effects of using gasoline and kerosene, but due to factors such as the wide range of sources of gasoline, kerosene, fast drying speed, and relatively low prices, printing companies cannot refuse. These advantages stand out in comparison with ink cleaners available on the market: Ink cleaners have specific conditions for specific printers, blankets, rubber rollers, etc.; special ink cleaners are expensive; supplies are also available Cannot guarantee full timeliness and so on.

Let gasoline, kerosene class

The use of gasoline, kerosene cleaning ink has the following drawbacks.

(1) The effect is not good

Although the use of gasoline and kerosene for the conventional cleaning of rubber rollers and blankets is very convenient and the results are satisfactory, gasoline and kerosene cannot do anything about the water-soluble components such as paper wool, paper powder, and gum arabic that are attached to the rubber rollers. A variety of impurities layered on the surface of the roller, it will close the original capillary pores on the surface to form a smooth crystalline layer, so that the roller size changes, severely affect the printing pressure, ink roller transfer performance decline , resulting in printing "meat bar", "flat net hair" and other printing failures. At the same time, a large amount of aromatic compounds contained in gasoline and kerosene can also cause the rubber to swell, affecting printing pressure and printing quality.

(2) security risks

Gasoline and kerosene are extremely flammable liquids, and the flash point (ie, the temperature at which the steam encounters an open flame) is only about two dozen degrees. If the ventilation facilities in the printing plant are not good, a dangerous situation such as a fire accident is likely to occur. This proved to be the case. Many printing companies exploded when workers used gasoline cleaning presses.

(3) unfavorable to the environment

Gasoline and kerosene contain a large amount of VOCs, causing serious environmental pollution and failing to meet environmental safety standards and causing greater harm to the health of employees. At the same time, most printing companies dumped the method of directly discharging gasoline and kerosene that had been washed with ink into the sewers. Needless to say, the pollution to the soil and water quality was at the same time. At the same time, the gasoline and kerosene that floated on the surface of the water were relatively high at outdoor temperatures. In the season, there is also the danger of explosion.

(4) Faced with elimination

In order to better promote the development of the printing industry, various countries in the world have started to formulate various regulations and standards for ink cleaning agents (car wash water) in 1995. These mainly include: Ink cleaning agents with a flash point below 21°C cannot be used For the cleaning of printing rollers and blankets (eg gasoline); The solvents containing halogenated alkane terpenes (turpentine), n-hexane, imines or acid amines shall not be supplied and used; the content of aromatic compounds in solvents shall 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, will rigorously test and regulate the use of chemicals on their printing equipment. Such as Heidelberg company has been rigorously tested, there are three types of car wash water that can be used on Heidelberg presses: 60, Superdot and Varn.

In order to undertake international business, some printing companies must pass the ISO9001 quality management system certification and ISO14001 environmental management system certification in accordance with the requirements, and naturally prohibit the use of gasoline and kerosene as ink cleaning agents. If it is said that printing companies used gasoline and kerosene in the past as a common choice to expand profits, then in today's increasingly fierce competition in the printing industry, using only petrol and kerosene to clean the ink in consideration of the material cost at the moment is a stare This is because it has significantly affected the social benefits and overall economic benefits of the printing industry.

With the large number of imported high-end printing equipments being put into use, as well as the security and environmental protection awareness of the printing company operators, environmental-friendly ink cleaners (car wash water) will become the main cleaning solvent for the rubber rollers in the future.

Know the ink cleaner

In fact, the current purpose of various ink cleaning agents on the market is to wash away impurities such as ink. In the printing process, many impurities generated by ink, water, and substrates can be roughly divided into two categories: One is the solvent. Type, that is soluble in organic solvents, such as ink oils, resins, colloidal oils, waxes, binders, and acid and alkaline substances in inks and additives; the other is water-soluble, ie soluble in water Or have affinity for water, such as gum arabic, casein, paper, paper powder, fillers and other inorganic compounds and hydrophilic pigments.

In this way, in order to achieve the purpose of cleaning, the cleaning principle is roughly the same, and the composition also includes the following types.

(1) Hydrocarbons

When the content of detergent is more than 50%, hydrocarbons can be divided into aliphatic hydrocarbons and aromatic hydrocarbons according to their molecular structures, and they all have better solubility in inks. Among them, aliphatic hydrocarbon molecules contain a chain structure of carbon molecules, can not be dissolved in water, no harm to the human body, rubber rollers and the environment; while the aromatic hydrocarbon molecules contain carbon molecules in the ring chain structure, The human nervous system has adverse effects, and long-term use may lead to cancerous lesions, which can expand the rubber polymer and have a certain influence on the rubber roller. Therefore, the content of the international ink cleaning agent stipulated in the quality standard should be less than 0.1%.

(2) Emulsifiers

Can promote the mixing of oil and water, resulting in emulsification; general flash point cleaners contain emulsifiers, will not cause residual chemicals on the roller and blanket.

(3) Anti-corrosion agent

Since the cleaning agent needs water to be cleaned, the anti-corrosion agent has the effect of preventing moisture corrosion.

Currently, the ink cleaning agents on the market are mainly divided into two parts according to their sources: First, they are imported, their products basically comply with the relevant international quality standards, but they are expensive; second, they are made domestically, their prices are moderate, but the quality is uneven, and some products have flash points. If it is too low, it can easily cause fires. Some products have high levels of aromatic compounds and poor environmental protection.

According to the type of technology, the ink cleaning agent can also be divided into two types: one is a pure solvent type, and it needs to be mixed with fresh water when used, but the ratio has an optimal value, and the best can only be achieved when this ratio is reached. The cleaning effect. In actual production, machine operators often cannot control the ratio of solvent and water very well, which not only results in a lot of waste, prolongs the cleaning time, but also affects the cleaning effect; the other is that the solvent has been used before production. Mixing with water in the best ratio, and adding the emulsion type ink cleaning agent made of emulsifier, its droplet size is very small, it is easy to penetrate the ink layer on the surface of the rubber roller, the cleaning effect is excellent, and the amount is only equivalent to gasoline 1/4 to 1/5. 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 we are referring to is mainly an emulsion ink cleaning agent composed of two organic solvents with different flash points, rubber antioxidants, and surfactants capable of forming stable water-in-oil emulsions. By emulsifying the solvent with water to emulsify the solvent into a W/O type emulsion system, gasoline can be directly substituted for ink cleaning.

The emulsion type car wash water is not flammable, and the storage safety is good, but the transportation volume is large and the use cost is increased. The cleaning performance of the emulsion car was related to the composition of the formula, especially the choice of solvent and active agent. At the same time, because the emulsion car wash water is a thermodynamically unstable system, it has poor stability and is easy to be stratified. Once it is stratified, it is difficult to deink, which affects the use, so its storage period is not too long. At present, some manufacturers have also introduced new types of ink cleaning agents, such as micro-emulsion car wash water, which do not require configuration and the thermodynamic system is stable, which makes up for the shortcomings of traditional ink cleaning agents.

However, in general, ink cleaners are superior to gasoline and kerosene in that they are highly efficient, energy-saving, environmentally friendly, and safe. They also have the effect of solvents and water. They not only remove ink, but also remove some water-soluble properties such as paper. The amount of dirt is small compared to gasoline (the same ink roller is used, and the amount of ink cleaning agent used is only 50% or less of gasoline). The ink cleaning agent has a slow volatilization rate, can fully exert its effect, and can greatly save the amount, but relative to gasoline. In terms of drying speed, it is slower.

Not just use

When we advocate the use of ink cleaning agents, on the one hand because the ink cleaning agent can save the printing company's overall cost; the other is mainly to hope that as a corporate social responsibility, must according to their actual situation for the environment and human health Take up your own social responsibility. Therefore, even if you disregard gasoline and kerosene and use an ink cleaning agent, it does not mean that everything is available, and the ink cleaning agent is not perfect. Although the ink cleaning agent has its own impact on the human body and the surrounding environment compared to gasoline and kerosene. To be small, but does not mean that there is no pollution; at the same time, like gasoline and kerosene, ink and other substances dissolved in the ink cleaning agent are harmful to the human body and the surrounding environment can not be ignored.

Therefore, while we use ink cleaners that meet international or national environmental standards, we must also ensure that the cleaned ink cleaners are well treated. It is not that we will clean the blankets, ink rollers, or machines that contain toxic inks. Material ink cleaners are poured directly into sewers and other places.

In this regard, foreign ink cleaning agent recycling method is worth learning, the principle is to reuse the used car wash water, wash the car wash ink and other toxic substances in a solid form separated out separately, and then continue to generate available car wash water ( The theoretical recovery rate is above 95%, and the actual recovery rate is above 85%, thus achieving an infinite number of repeated cycles. This not only avoids the pollution of car wash water to the environment, but also saves more than 85% of car wash water, which also means savings of more than 85% of related production costs. At present, many foreign printing companies have used relevant processing equipment to recycle the used car wash water, and the economic benefits are very significant.

Whether it is from the cost of the company or from the perspective of social responsibility, don't neglect your ink cleaner.