Use efficient ink cleaner

From the beginning of the 20th century to the present, in the past 100 years, lithographic offset printing processes, printing equipment, and matching printing materials have made considerable progress. Offset printing has become an important printing method dominated by the printing industry's Aerospace Department. .
The inking system of a lithographic offset printing press is generally composed of an ink supply roller, an ink transfer roller, a uniform ink roller, and an ink application roller. In the long ink, a high viscosity ink is supplied to the printing plate. The number of ink rollers in a printing unit can reach more than 20, and the cleaning and expansion are directly related to the service life and printing quality of the ink roller.
Compared with the gravure printing machine and the flexo printing machine using the short ink inking system, after the lithographic offset printing machine prints, the amount of cleaning agent consumed for cleaning the ink roller is enormous. Therefore, the cleaning agent for offset printing ink roller, whether it is quality or price, has always been the concern of lithographic offset printing companies.
First, the use of gasoline to clean the ink roller must be eliminated. Currently, most printing companies in China still use the ink roller to clean the printer. There are two reasons. First, the price of gasoline is low; second, the workers' long-term and petrol cleaning ink roller. It is common practice for cleaning procedures to be considered simple, convenient, and unwilling to switch to other cleaning agents. In fact, it is not very good to clean the ink roller with a single gasoline. It is often necessary to mix a certain amount of kerosene in the gasoline to remove the ink from the ink roller. In practice, after the operator of the offset printing press cleans the ink roller by adding kerosene and kerosene, it generally uses the pigment particles that do not erase the paper hair and paper powder attached to the ink roller. The workers have a deep understanding that using petrol and kerosene solvents to clean the ink roller not only takes a long time, but also the labor is not low.
Gasoline is divided into gasoline and leaded gasoline. Lead-free gasoline, although containing no tetraethyl lead compounds that can be directly absorbed by human skin and causing lead poisoning, contains volatile oils composed of very low boiling point n- and n-hexane. Volatile oils have the effect of inhibiting the central nervous system of the human body and can easily lead to blood poisoning. Gasoline has a flash point of 21 degrees Celsius and is a flammable liquid that is easy to charge. When petrol was used to clean the ink roller, the gasoline molecules were warmed everywhere in the workshop, which not only seriously jeopardized the health of the human body, but also caused fire hazards. There was a fire caused by Dyne gasoline in the printing industry in China. Therefore, regardless of improving the cleaning effect of the ink roller, or from the perspective of environmental protection and safe production, prohibiting the use of gasoline to clean the ink roller has reached a moment of urgency.
Second, high efficiency ink cleaning agent principle of cleaning ink Lithographic offset printing is not compatible with the principle of water to print. The offset printing machine uses a water supply device to supply a dampening fluid to a blank portion of the printing plate, and the ink supply device supplies ink to the graphic portion of the printing plate. When the printing press presses and prints, due to the high printing speed, the ink is forcibly formed between the water roller, the ink roller and the printing plate gap and the nip between the rollers. It can be seen that the ink delivered on the offset press is not a pure ink, but a water-in-oil emulsion ink.
Common wetting fluid is mainly water, phosphoric acid, phosphate and peach gum. Typical offset inks consist of binders (solid resin and liquid resin), high-boiling kerosene with a boiling range of 270 degrees Celsius to 290 degrees Celsius, pigments (such as phthalocyanine blue, lithopal red), and desiccants (cobalt naphthalate, manganese naphthalate). ) and wax additives and other components. Ink emulsion ink contains both the components of the ink, but also contains various components of the wetting fluid, including binders, pigments, inorganic salts, water and peach gum. The printer delivers high-viscosity inks. Paper powder (paint particles) and paper fluff (fine fibers) pulled from the surface of the paper are also incorporated into the emulsified ink. According to the chemical principle of similar structure and mutual solubility, the linking material is an organic substance and can be dissolved in organic solvents; natural plant fibers and peach gum are organic substances, but due to the molecular structure containing more hydroxyl (-OH), its hydrophilicity Far more than lipophilicity; pigments are neither soluble in water nor soluble in oil, but have good affinity with water; both coating particles and inorganic compounds are soluble in water. Gasoline and kerosene, which are cleaning agents, can only dissolve the linking material in the ink, and there is no washing effect on the production, peach, inorganic salts, paper powder, and paper hair in the emulsified ink. Therefore, after washing the ink roller with petrol and kerosene, it is necessary to scrub the paint, paint, glue particles, and paper hair remaining on the ink roller with water. If the scrubbing is not done, the pigments, gel particles, paper logs, and paper powder will permeate into the pores of the ink roller adhesive layer to form dirt, which will degrade the ink transfer performance of the rubber roller and seriously affect the printing quality.
High-efficiency ink cleaning agents consist of organic solvents, water, surfactants that form a stable water-in-oil emulsion, and protective agents that prevent the aging of the ink roller blanket. The organic solvent in the cleaning agent dissolves the binder in the ink, while the water dissolves the inorganic salt compound and wets the pigment and paper. It is easy to wash off the emulsified ink on the surface of the ink roller to avoid the conjunctiva and pile of the ink roller. Ink, improve print quality. At the same time, it can prevent the aging of the ink roller and prolong the service life of the ink roller.
The quality characteristics of high-efficiency ink cleaners are mainly manifested in the following aspects.
1. With excellent cleaning function, it can thoroughly wash away the impurity residue on the offset roller, including the ink composition, peach gum, dampening liquid debris, and the paper powder and paper hair that have fallen off from the paper and mixed into the ink. Roller has good ability to support expansion.
2. Does not contain harmful substances, will not harm the user's health, nor will it pollute the surrounding environment. Its flash point range is more than 2 times higher than gasoline, about 42 degrees Celsius - 66 degrees Celsius. Fire will not detonate.
3. Easy to use. When cleaning the ink roller, take a certain amount of cleaning liquid from the bucket into the container, then inject 1/4 (volume ratio) of tap water into the container, shake gently, and turn it into a milk-like emulsion. Pour on the surface of the ink roller, jog the machine, and then put on the scraper, start the machine, and the ink and impurities can be quickly washed away. If the offset press is equipped with a device for automatically cleaning the ink roller, simply inject the emulsion into the cleaning tank and press the wash button to clean the ink roller.
After the Second World War, many countries in the world that paid great attention to environmental protection developed inks in succession, and they gradually used them in offset printing production.
Third, the characteristics and application of efficient ink cleaning agent After 90 years, Australia, Germany and other countries, have all used high-efficiency ink cleaning agent to clean the offset roller, gasoline was completely replaced.
In our country, the use of high-efficiency ink cleaners began around 1995. At present, many printing manufacturers in China are using high-efficiency ink cleaning agents, such as the China Business Printing Co., Ltd. of Shenzhen, limited to the company, Guangdong Humen Color Printing Co., Ltd., Beijing's People's Fine Arts Printing Factory, Hualida Color Printing Factory, and Economic Daily. Social Printing Factory, Glorious Stone Color Printing Factory, Yuanyi Printing Co., Ltd. According to the manufacturer's report, when it was first used, it was felt that the price of such an efficient cleaning agent was more expensive than gasoline, and some of it was unbearable, and there was a fear of increased printing costs. However, after a period of use, we found that its consumption was only one-fifth that of gasoline. Not only was the time taken to clean the ink roller short, it saved man-hours and labor, and the cleaning quality was high, prolonging the life of the ink roller. After a comprehensive evaluation, the use of this cleaning agent actually costs less than gasoline. All manufacturers that use high-efficiency ink cleaners have achieved good economic and social benefits.
High-efficiency ink cleaning agent is an environment-friendly cleaning agent that is pollution-free and conducive to safe production. It should be vigorously promoted and used. This is of great significance for improving the quality of our offset printing products and improving the printing operation environment.