Cleaning agent and cleaning method development trend

In recent years, in order to protect the environment, the use of environmentally friendly materials and cleaning methods has become increasingly demanding. The cleansing operation has gradually changed from the simple requirement of high speed and low cost to the requirement of more safety and environmental protection. To this end, with Europe and the United States as the center, developed countries are actively developing a new generation of environmentally-friendly products, and new cleaning technologies that do not harm the health of operators are constantly being promoted.
This article mainly introduces the cleaning methods of printing plates and printing machines in flexo and gravure printing and the development trend of cleaning agents. The cleaning methods in the article, whether physical cleaning or chemical cleaning, are environmentally friendly methods.
1. The Importance of Cleaning To print high quality prints, you must control the transfer of ink. In order to achieve good transferability, it is important to clean the anilox roller to avoid blocking.
For a long time, most printing manufacturers use highly volatile organic solvents such as toluene, n-hexane, methanol, and MEK (methyl ethyl ketone), or corrosive acids, and cleaning agents such as sodium hydroxide and ammonia. When using these cleaning and cleaning products, the surface of the printing plate and the anilox roller is generally cleaned with a cloth or a brush, or the object to be cleaned is soaked in the tank for a period of time before cleaning.
The following factors must be considered in the cleaning operation.
1) The position of the anilox roller, plate, and printer to be cleaned is small;
2) Use a physical cleaning method that does not require moving the cleaning material;
3) Does not affect production efficiency;
4) Determine the cleaning method and;
5) Use a low-cost cleaning method.
In any case, the younger generation was involved in the shutdown of the printing or coating process, but it was still a job that added burden to the operator.
2. The current status of cleaning operations Cleaning of printing plates and printing presses can be performed directly on the machine. The drums can also be removed and cleaned. The required equipment should be prepared according to the specific conditions.
The method of cleaning directly on the machine is the most common. When this method is adopted, there are two options:
1) Use cleaning device;
2) Do not use cleaning devices, mainly chemical and manual cleaning.
The former uses the second method because it takes time and trouble to install the cleaning device.
In order to protect the health and safety of cleaners, some developed countries in Europe and America have recently established standards. For example, in order to avoid cleaning agent's skin irritation, ACGIH of Canada and OSHA of the United States strictly regulate the exposure time of cleaning agent. In addition, the United States' D. O. T (Transportation of Hazardous Substances) stipulates that when using cleaning agents, rubber gloves must be used in accordance with the law and glasses must be worn.
In order to prevent the pollution caused by the printing and cleaning operations, the relevant authorities have been calling for the replacement of toluene and other organic solvents with solvents that have a low VOC content in water. However, aqueous cleaners also have deficiencies and are generally not suitable for cleaning solvent-based inks or coatings.
3. Physical Cleaning Methods 1) Sodium Bicarbonate Cleaning Recently, the use of a high-pressure method for internal cleaning of webbing has been a constant promotion. This method is a safe and hygienic cleaning method, but it requires water vapor or water to wash out sodium bicarbonate powder after cleaning.
2) Dry Ice Cleaning Method A few years ago, the United States developed a dry ice cleaning method (injecting ultra-fine dry ice from air ducts with high pressure). In addition, methods of cleaning with plastic particles are also being explored. In this method, compressed air is used to inject ink particles having a lower hardness than the anilox roller but harder than the dry ink in the anilox roller ink-receiving hole, thereby rinsing the ink in the ink hole.
3) Ink tank cleaning method The ink tank assembly is widely used for flexo printing, gravure printing and offset printing.
The ink tank is a device that supplies ink directly to the printing plate in the web because it is completely closed and the agent does not volatilize outside, which is environmentally friendly. With the ink tank structure, automatic cleaning can be completed.
In the ink chamber device, a special structure is arranged to make the flow clear or countercurrent, and the anilox roller can be rotated at the same time. The nozzle can be set in the ink tank, and the cleaning agent can be sprayed with high pressure to the anilox roller. Clean it.
4) Ultrasonic cleaning This cleaning method consists of placing the anilox or plate cylinder in a cleaning tank and using a roller or roller while emitting ultrasonic waves for cleaning.
4. Chemical cleaning methods As mentioned above, European and American countries have developed cleaning agents that can ensure the health of cleaning personnel.
When using this kind of cleaning agent, pay attention to its matching with the ink. If the ink cleaner lacks affinity, the ink will easily emulsify after cleaning.
Recently, there have also been developed colloidal cleaners that do not corrode metals. When using, only hydrogen glue cleaner is needed, and then it can be wiped off with water or washed off with water. Some of these cleaning agents also contain organic solvents or strong alkaline substances such as sodium hydroxide. The latest trend is the development of safe cleaning agents made of vegetable oils.
In addition, the water-based cleaning agent used for cleaning the ink contains some organic acids such as strong acids, strong bases, or methyl ethyl ketone/alcohol, and care must be taken when using them.
1) Solvent-based Flexo Printing Clear First, the cleaning agent is required not to expand or degrade the flexographic plate, and it is also required that the cleaning agent be used for cleaning plates, anilox rollers, and ink containers at the same time. In particular, solvent inks or UV inks can be efficiently and safely cleaned.
2) Gravure Printing, New Printing Cleaning Agents Gravure inks and offset printing inks usually use high-level cleaning fluids. The new cleaning fluid will not harm the health of the operator and improve the operating environment.
5. Various cleaning agents 1) Ink, coating cleaning agent New ink cleaning agent does not contain strong acid, strong organic solvent, vegetable oil as raw material, with microbial decomposition. The integrated cleaning agent can be used for cleaning plates, anilox rollers, ink tanks, ink fountains and ink tubes. There are daily cleaning type, regular cleaning type and hand-washing type.
2) Solvent inks, UV inks, and cleaners for less materials From a new point of view, the Netherlands-based FlexoClean Engineering has developed solvent-based ink cleaners that use microbial decomposition properties, UV inks, and paint cleaners.
a. Solvent type cleaning agent (for solvent ink)
It does not contain strong acids, alkalis or organic solvents. The cleaning agents based on vegetable oils are not irritating to the skin and do not pollute the working environment.
Such cleaners are colorless, have a sweet odor, and have a boiling point of 184 degrees Celsius to 230 degrees Celsius.
When cleaning, spray the raw liquid directly, place it for one minute (make the ink dissolve), and wipe it again with a dry cloth, if it can clean with a brush. Suitable for on-machine cleaning of anilox rollers, gravure cylinders, partially offset PS plates, flexographic plates, and impression cylinders.
b. UV cleaning agent (for UV inks)
Such cleaners are colorless, transparent, and have a boiling point of 225 degrees Celsius. When cleaning, spray the stock solution directly. After a minute (make the ink dissolved), wipe it several times with a dry cloth. It can also be diluted with 1 part of the cleaning solution against 3 parts of water. This diluted cleaning solution can be used for cleaning the ink circulation system (ink tank, conveying pipe, ink container), but is not suitable for cleaning solidified ink. Suitable for cleaning using UV inks, UV varnish presses, plates, rollers, etc.
In summary, cleaning is not only the final step of printing and coating processing, but also the preparation for the next job. The environment-friendly cleaning fluid has a very good cleaning effect. Paying attention to environmental protection will be the development trend of future cleaning operations.
The rise of printing service companies With the development of the market economy, people have greatly increased the demand for high-end books, calendars, commercial promotional products, and color packaging and commercial forms for light industrial products. The traditional layout of the printing factories can no longer meet market demand. In particular, the rapid development of electronic products has led to the development of high-tech desktop systems, digital direct printing and network transmission, and the production of high-quality products, so that it has a very professional and personalized graphic design and plate making center and output center. Proofing companies and binding companies came into being. However, these companies are only a part of the printing process, and they cannot fundamentally solve the problem of linkage between processes. As a result, printing service companies set up a bridge between processes.
Most of the employees of printing service companies are professionals with both theoretical basis and practical experience. They are proficient in the printing process, are familiar with new technologies, and are familiar with the production characteristics of the various printing companies in the region (including the equal main technical force of the equipment), are familiar with the materials and prices, and have certain social relations and understand social needs. I have been doing this industry for many years. Compared with the past years of practice in large state-owned factories, I have the following understanding:
1. Thoughtful and extensive service and skilled business skills have tapped market potential. The printing industry is a small business compared to other industries, but it penetrates into all areas of society. It can provide services for multinational corporations, foreign consulates, primary schools, streets and individuals; it produces products ranging from albums, fine packs to letterheads, envelopes, business cards and photocopies. In addition to providing printing services, printing service personnel can also help various industries in the society to do product promotion and image positioning. Some small and medium-sized companies responsible for publicity are often held by the secretary. They are not familiar with advertising design and printing. At this time, the role of printing service personnel will be even greater. I have encountered such a thing in practice: when a lady of a foreign airline works as a promotional item, she does not know what to do. I consulted from design centers and other places and learned about some publicity materials of several other airlines. She also referred her samples to her references. According to the actual situation of the company, I regularly produced airlines, timetables, and other advertisements. This kind of service mobilized its enthusiasm and increased its self-confidence. We also introduce some other company's business to us.
2. The production of products is more sophisticated and the printing cycle is shortened. Usually after a print is placed in a factory, it is often processed according to the factory's procedures. Printing service companies are not the same to undertake business. Such companies understand the overall situation, according to the quality of the product requirements and the specific circumstances of the cycle, choose a different unit, or even a number of live choices, choose the best choice, working hours are also very flexible, live to work, no live break , No eight-hour working day, no holidays.
3. The flexibility of the production mechanism and changes in the distribution format have attracted some professionals to enter the printing service industry and are relatively stable. In the past, there were very few design talents and computer experts needed by the printing industry. Many institutions of higher learning and computer professionals were unwilling to go to the printing house design studio and computer room for printing and printing... Taxi’s own business. In accordance with the needs of the market, we will conduct business with our own wishes and achieve certain achievements. While others work in the same position, they use spare time to do some design, graphic processing, and printing. Compared with their counterparts in the factory, they have more freedom, and no matter what their sense of accomplishment or income can be compared.
Printing service companies, like those of other industries, are concise, have less investment, and have quick results. There are no funds backlogs and waste of raw materials.