Lamination: An Unavoidable Finishing Process

The lamination process is a surface processing process after printing, and is also known as post-press lamination, post-printing lamination, or post-printing film. It refers to the laminating machine covering the surface of the printed material with a layer of 0.012 to 0.020 mm. Thick transparent plastic film forms a paper-plastic product processing technology. In general, according to the process used can be divided into two kinds of coating film, pre-coating film, depending on the film material is divided into two kinds of light film, matt film.

As a process of protecting and decorating the surface of the printed matter, the film has a large share in the post-press processing. If you walk into a bookstore, you will find that most books use this method. This is because the surface of the printed matter that is covered by the film will be smoother, brighter, stain-resistant, water-resistant and wear-resistant. The color of the cover of the books and magazines will be more colorful and difficult to be damaged, and the abrasion resistance, folding resistance, and tensile resistance of the printed matter will be improved. Moisture resistance has been greatly enhanced, protecting the appearance of various types of printed products and increasing the service life. What is most worth mentioning is that the film can largely compensate for the quality defects of the printed products. Many apparent defects appearing in the printing process can be covered after the film is covered (especially after covering the film). .

Therefore, the film coating process is widely used in China in various types of packaging and decoration prints, books and magazines in various binding forms, books, calendars, maps, etc., and is a very popular printing surface processing technology. Laminating technology entered China in the 1980s. Because of its many advantages, it has swept the country in a very short time and gradually became the darling of the surface decoration of books and periodicals.

Nowadays, people’s awareness of environmental protection has gradually increased, relevant laws and regulations have been continuously improved, and the two major problems of pollution generated during the lamination process and the difficulty of reuse during the disposal of coated products have been placed in front of people. "White pollution". Many people in the industry have doubts about the function of the film and whether it can continue to be applied. In former Order No. 32 issued by the State Economic and Trade Commission in 2002, solvent-type coating machines have been included in the third batch of elimination of backward production capacity. Catalogue of Processes, Processes and Products.

It is certain that in the future development process, the lamination technology will accept more and more tests. How will the film be developed? Is it completely eliminated or reasonably developed? These problems will become unavoidable problems in the development of the lamination process.

The status quo is worrying

When we visited exhibitions of books and products, it was difficult to see products on the foreign booths that were covered. In some developed countries, the laws and regulations on environmental protection, health, and fire insurance are relatively perfect, making it difficult for film-covered processes to develop. On the contrary, China's film-covered market presents a scene of “prosperity”. To talk about books and magazine decorations, we must talk about the film-covering process.

1. The main problems in the film coating process

Although the regulations for disabling solvent-type coating films have been introduced for many years, many small-scale film coating plants in China still continue to use them. It is understood that this process mainly has the following problems.

(1) Impact on the health of operators, and there are fire hazards

Solvent-based coatings use benzene-containing solvents, impair the health of operators, and cause significant pollution in the workshop environment. At the same time, with the continuous increase in the concentration of the surrounding organic solvents, it is very easy to cause sudden fire due to the static electricity generated by the film material. And for the surrounding environment, the film-covered factory itself is a serious source of pollution and is potentially dangerous.

(2) The coated paper and film materials are difficult to recycle and waste resources

It is understood that 80% of China's papermaking fiber is based on the recovery of waste paper, including paper, paper and paper. In the printed matter, the amount of paper on the cover of the book is also huge. If the film is used in large quantities (especially coated material), it is impossible to separate the paper from the plastic film, then the used paper over the film and the edge of the paper Paper and wool will not be recovered and cannot be degraded. This will bring about unpredictable economic losses. It is actually a waste of resources.

2. The reason why the lamination process is behind but still has a market

Why is there still such a big market since solvent-based coatings are so harmful? The following reasons more or less determine the reason for its existence. First, laminating machines using solvent-based adhesives have been used for many years. The development of the equipment is very mature, and the precision of the lamination is guaranteed. These machines are generally not easy to damage and maintenance is not complicated, and they have accumulated a lot of production during long-term use. And maintenance experience, so many manufacturers are reluctant to use this kind of solvent laminator can also be eliminated. Second, the solvent-based coating process has been promoted for decades. The technology is mature and product quality is guaranteed. Many companies and technicians are reluctant to replace their own skilled craftsmanship with a technology they are not familiar with. Third, from a cost point of view, solvent-based laminating machines are still relatively cheap. For print shops, the cost savings is to strive for profits. Fourth, although the water-based film coating process has improved the environmental problems in the production process and has avoided the damage to the operator's body, it still has many defects compared to the solvent-based film coating process, such as the product quality is difficult to satisfy.

3. Attitudes of printing houses and publishers affect film development

Overall, it is only a matter of time before the solvent-based lamination process is completely phased out. Through interviews, we have also proved this trend. It is foreseeable that the solvent-based film has come to the stage of exiting the stage of history. However, can we use this to completely negate film technology? The author believes that under the present circumstances, the idea of ​​completely eliminating the coating technology is unrealistic, and the following two aspects deserve our attention.

(1) It is difficult for printers to make profits

For most printing companies, laminating is a big profit point in the post-press processing industry, especially since the printing industry has entered the era of meager profits. For the laminating process, the printing factory is difficult to give up.

The first-line operator of the film is the first victim of harmful gases. What we can comfort is that the current printing plants (even some small-scale printing plants) can generally recognize the dangers of the lamination process and are Try to reduce possible pollution to the minimum, such as the use of more environmentally friendly processes and materials, improve the plant's ventilation facilities, etc., They welcome environmentally friendly products, such as water-based film, pre-coated film.

(2) Press lamination has become a habit

The laminating process is highly praised by publishers. The US editors often choose the laminating film when choosing the decoration method for the surface of the books. Even when coating with local UV, the laminating film must be coated and then glazing. It can be said that the publishing house plays a decisive role in whether the film is covered or not, because according to the general book publishing process, the publishing house must first formulate a plan, and the printing house or the binding factory is only in the execution of the publishing house. Some science and education publishers will cover almost all books. On the issue of environmental protection, it is clear that there is no printing house on the publishing company side to behave positively.

While people's living standards have improved, the requirements for the print quality and surface decoration of paper publications have also been greatly improved. In order to pursue the sales of book products, publishers need to make a big fuss on the cover of books and magazines.
After the paper publication is processed by laminating, the graphic and text can be protected and the visual effect is better, especially the matt film gives a soft, high-grade and comfortable feeling.

In addition, the film can also increase the color concentration and brightness, improve the color contrast, but also waterproof, not sticky. At the same time, the physical properties such as paper tension, smoothness, anti-aging, tear resistance, and anti-jamming are generally improved, which reduces the deformation and damage caused by the influence of moisture on the paper, and improves the rigidity and forming stability of the book. Greatly increased the added value of prints. Moreover, the investment in filming costs is much lower than the added value of products and the promotion rate of goods. For publishers, since there are so many benefits for the film, why not?

Therefore, the publishing unit and the printing factory should strengthen communication. The printing factory should introduce the advantages and disadvantages of the film coating process to the publishing unit. The publishing unit can take into account the advantages and disadvantages of various processes and take a society Responsibility to do design.

Henan impression

At present, some provinces and cities in China have issued relevant regulations prohibiting students from laying textbooks. Henan Province is a typical example. I was surprised when I heard about it. In general, students' textbooks are the most in need of lamination, especially the textbooks of primary school students. The children are active and active, and the textbooks are also worn out. Therefore, the functional requirements of folding, abrasion, and waterproofing of books are also compared. high. Moreover, at the recent NPC session, many delegates proposed to realize the reuse of students' textbooks. If this goal is to be achieved, it should be necessary to cover textbooks.

But why is it forbidden for student textbooks? On the one hand, we have also repeatedly emphasized that the printed film is subject to the idea of ​​environmental protection and sustainable development. Even if it solves the problem of pollution in the production process, at present, under our country's technological level, recycling after discarding can not achieve. On the other hand, film lamination increases the cost of textbooks. This cost is not only the cost of laminating the finished books, but also the cost of paper wool and paper powder that are discarded during processing. Since this part of the scrap cannot be recycled, the cost can only be reduced. Fully added to the pricing of each book that is covered, this is also a burden for the users of the book.

It is understood that the film coating factory under the Henan Press and Publication Bureau was revoked after the ban was issued. Since textbooks account for the vast majority of laminated products, many of the larger printing factories in Henan Province (such as Henan Xinhua Printing Factory and No.2 Xinhua Printing Factory) have long since cancelled the post-printing form of the film. Encountered need to cover the product, they took other small plants to film. Many of these large-scale printing companies had already eliminated solvent-based coatings and water-based coatings before the removal of the coating process, and used more advanced pre-film coating. After the ban was issued, they gave up the film. According to the relevant personages of a printing plant, the printed matter of the film-covered publications printed by the factory now accounts for 20% to 30% of all the printed products. It should be known that this number should reach 70% or more.

It can be seen that the government’s enforcement measures have caused the film to lose a large market in some areas. However, from a nationwide perspective, it is necessary for us to revisit this kind of technology that makes people “love and hate”. In fact, as part of the printing technology, the film coating technology is also developing with the continuous advancement of various materials, equipments, and processes, just like the progress of solvent-based coating to water-based coating, that is, coating-type coating technology to pre With the advancement of coating technology, the continuous advancement of various thin film materials and various adhesive materials, this trend is also irreversible, and this is also the hope for the reform of the film coating technology.

Seek development

The continuous improvement of printing technology, the continuous updating of printing materials, the ever-changing factors of post-press processing conditions, and the increasing impact on the laminating film, the ever-increasing printing quality standards and market demands. This requires the laminating industry to change according to objective conditions. New quality and technical standards for structural adjustment. At the same time, we should also look for other processes that can replace the film in a timely manner to reduce the pressure of the film on the environment.

1. Varnish can replace the film

In fact, in addition to the laminating process, UV coating can also play a role in protecting and decorating the surface of the printed material. In many functions, the two are very similar. As the cost of UV coating is relatively low, the development is relatively rapid, and the product is very attractive, so it also occupies a certain market share in some areas of post-press processing. Some people who are optimistic about UV glazing technology even believe that this technology can be independently developed instead of film coating technology.

In fact, this is just a wish of people. According to some printers applying the UV coating technology, UV glazing is mostly applied locally. Local UV polishing can improve the quality of books, but in most cases, this local UV coating process is also After filming