1.Development history of thermal lamination film industry
The product is combined with the film by a professional laminating device to form a paper-plastic product. This technology is called lamination. After the film is printed, the surface is brighter and smoother, the pattern is more vivid, and the performances such as abrasion resistance, folding resistance, tensile strength, moisture resistance and chemical corrosion resistance are also strengthened, and even some apparent defects in the printing process can be It is largely compensated, so not only the service life is extended, but the aesthetics of the product is also greatly improved. Since the birth of the film-coating technology in the 1950s, the film-coating technology has experienced three important development stages: solvent-based coating technology, water-soluble coating technology, and thermal lamination technology.
(1)The revolution in packaging materials led to the birth of solvent-based coating technology
In the 1950s and 1960s, the successive birth of BOPET (biaxially stretched polyester), BOPP (biaxially oriented polypropylene), BOPA (biaxially stretched nylon) and other film products promoted the revolution of packaging materials in the world, which led to the aim The birth of the coating technology for post-press film processing. Among them, BOPP film plays a vital role in this revolution due to its reasonable price and wide application.
The BOPP film was invented in 1958 by the Italian company Montecatti and industrialized in 1962, and subsequently developed rapidly around the world. BOPP film has the advantages of light weight, non-toxic, odorless, moisture-proof, high mechanical strength, stable size, good printing performance, good transparency, reasonable price and low pollution. It also reduces the use of paper packaging and strengthens the pair. The protection of forest resources, the birth of BOPP film quickly led to the transformation of the packaging materials industry, and began to be widely used in the packaging of food, medicine, daily necessities, etc.
With the rapid development of the packaging industry, Solvent Laminating Technology was invented in the United States in the late 1950s and entered China in the late 1960s. It still occupies a dominant position in China's film market. The solvent-based coating technology is a solvent-type coating which is blended with a benzene solvent by a dedicated coating film device, and is coated on a film, dried, heated, and pressurized to be combined with the printed product. The coated film has a bright, smooth surface, a more vivid pattern, wear resistance, folding resistance, tensile strength, moisture resistance and chemical resistance, thus enabling instant coating technology to be rapidly promoted.
(2)The improvement of environmental protection requirements in developed countries has led to the development of water-based coating technology
After entering the 1970s, the awareness and governance of environmental protection in developed countries has gradually increased. Solvent-based coating technology can cause serious damage to the health of producers and consumers due to the use of benzene solvents, which may lead to leukemia and infertility. Such diseases, as well as organic solvents in the processing plant are also potential fire hazards, developed countries pay more and more attention to their hazards. In order to solve the above pollution problems, water-based coating technology came into being in Europe and the United States in the late 1970s.
The water-based coating technology is based on the original solvent-based coating technology, and replaces the organic solvent glue with a non-toxic and harmless water-based glue (ie, aqueous acrylate adhesive) to solve the pollution problem of the solvent-based coating technology. . Because it has the advantages of solvent-based technology and environmental protection, it has been rapidly promoted and entered China in the mid-1990s. It still has a market share of about 35% in the European market.
(3)Improvement of environmental protection requirements and the printing industry revolution promoted the birth and development of thermal lamination technology
Although the water-based instant coating process solves the problem of solvent-based benzene contamination, it has the problem of pollution after requiring a large amount of water to clean and discharge the cleaning waste water. It is still not an ideal environmentally friendly coating solution, and at the same time, it is in product quality and There are still some defects in production efficiency.
In the 1980s, with the birth of laser photo-alignment technology and offset printing technology, the printing industry ushered in a revolution, and it has since entered an era of high speed (from 2,000 prints per hour to 18,000 prints per hour), automation, and information technology. In addition, the post-press processing requirements are more exquisite, and the market printing order demand has also shifted from the original long version (ie, single variety, large batch, long time) to short version (multi-variety, small batch, fast and even 24 hours delivery).
Due to its own technical bottleneck, the traditional instant coating technology has been difficult to adapt to the requirements of the development of printing technology: First, the coating technology is low in efficiency. Since the laminating process requires glue coating and drying, the laminating speed is limited to 15-30 m/min, which is far from meeting the post-press processing requirements after high-speed printing. Second, the quality is low. The coating technology is easy to cause problems such as blistering, wrinkling, graying of the color, deformation of the paper, and discoloration of the graphic. Thirdly, the emergence of digital printing technology has put forward new requirements for film coating, that is, coating technology cannot be used for digital printing, only thermal lamination technology can be used.
In 1989, GBC Company in the United States responded to the needs of printing technology revolution. After years of research, it successfully developed thermal lamination film technology and created a new era of post-press film coating technology.
The thermal lamination film is a film-coated product which is adapted to a non-toxic and harmless hot-melt adhesive layer of a material to be bonded, and which is combined with a film substrate satisfying the corresponding technical requirements by a special process. The production process is that the thermal lamination film manufacturer will meet the specific technical requirements of the film materials, such as BOPP, BOPET, etc., through special equipment for electrical treatment and heating, pressure treatment, and through the extruder through high temperature and high pressure flow generation The hot melt adhesive is compounded into semi-finished products, and then processed into a finished product that meets the size requirements of the printed packaging film according to the requirements of the customer's product size. Printing and packaging enterprises do not need to do any glue coating process on the film during the film coating process. They only need to be heated and pressurized by a special laminating machine. The operation process is simple and pollution-free.
The unique production process and laminating process of the thermal lamination film make it environmentally friendly, capable of high-speed film coating (60-100 m/min), high film quality, high bonding strength, exquisite post-printing, good post-film processing performance, etc. The advantages, so it was quickly promoted in the United States once it was launched. In 1996, the United States achieved a comprehensive replacement of instant coating technology by thermal lamination technology, which currently accounts for 95% of the film coating market. Since Europe is the birthplace of water-based coating technology, the promotion of thermal lamination film has been slow at first, but in recent years, the market share of thermal lamination technology has gradually increased steadily, and it has reached 65%. Japan and South Korea began to promote thermal lamination films in the 1990s, and have now reached market share of about 70% and 50% respectively. 1 At the same time, the birth of thermal lamination film made the film of digital printing products possible, which led to the emerging market segment of commercial printing film.
Not only the thermal lamination film was born in the revolution of the printing industry, but also some other post-printing surface finishing processing technologies have been developed, including the UV glazing technology which is widely used at present. UV glazing refers to the printing of a special special coating agent applied to the performance or local area of a printed matter after precise and uniform application. After UV irradiation, the coating agent is dried and hardened on the surface of the printed product at an extremely fast speed. Post-processing technology. UV glazing technology can be used to modify the entire surface of the printed product, or to perform local UV glazing on the printed film to achieve special artistic effects. UV glazing technology can play a certain role in protecting and enhancing the printing. However, UV glazing does not occur in the composite process with the film, and the wear resistance and folding resistance are poor. Although it can bring good appearance, it protects the printed product, prolongs the service life, and reprocesses the film. Not competent. At the same time, UV glazing prints are not conducive to further post-processing on the surface (such as indentation, embossing, bronzing, etc.), so the print quality and artistic effects of the printed products are also affected and limited. Therefore, UV glazing is generally used for short-term readings and simple packaging, and the space in the high-end printing market is limited.
The thermal lamination technology has been mastered by developed countries since its invention. In 1998, the controlling shareholder of the issuer, Beijing Kangde Electromechanical Development Corporation (now known as “KDX Group”), started the research and development of the technology and was formerly the State Economic and Trade Commission. It will be included in the 2000 National Key Technology Innovation Project and will be supported. After four years of hard work, through independent research and development combined with technical cooperation, the issuer mastered the thermal lamination film production technology with independent intellectual property rights, and on October 16, 2002, it completed the production of China's first thermal lamination film production line. In recent years, with the increase of national environmental awareness, the market demand brought by the improvement of national printing technology and quality requirements, and the related policies gradually introduced by the state, China's thermal lamination film industry has made great progress.
2.Classification of thermal lamination products
According to the substrate division, the thermal lamination film can be divided into BOPP thermal lamination film, BOPET thermal lamination film and BOPA thermal lamination film. BOPA thermal lamination film is a thermal lamination film based on BOPA film (or biaxially stretched nylon film). It has good barrier properties, puncture resistance and impact resistance, high brightness, good heat sealability and Hygroscopicity and printability can meet the requirements of some high-end customers for post-film products.
According to market application, it can be divided into industrial printing thermal lamination film, commercial printing thermal lamination film and special-purpose thermal lamination film. Among them, the industrial printing market mainly refers to the printed matter of publications and the packaging film of consumer goods such as food, medicine and daily necessities; the application of the main printing code market in the emerging field of index printing, card certification, anti-counterfeiting, commercial advertising, etc.; special-purpose market Mainly refers to building materials. The latter two types of markets are emerging markets that were born with the emergence and development of thermal lamination technology.
The European, American, Japanese and Korean companies represented by GBC have been in the leading position in the international market, especially in the middle and high-end market, due to their early start and mature technology. However, in recent years, the Chinese thermal lamination film industry represented by the issuer and the Indian thermal lamination film industry represented by COSMO have risen rapidly due to their lower product prices and product quality levels close to those of GBC and other companies. Already moving to Asia.
Analysis of the development status of upstream industry
The main raw materials for the thermal lamination film manufacturing industry are BOPP film, EVA hot melt adhesive, BOPET film, and LDPE hot melt adhesive. The industry development status is as follows:
1.Status of BOPP industry
BOPP film (or biaxially oriented polypropylene film) is obtained by co-extruding polypropylene particles into sheets and then stretching in both directions. It is used as a base in the production of BOPP thermal lamination film. material. BOPP film is light, non-toxic, odorless, with good physical stability, mechanical strength, air tightness, high transparency and gloss, good printing performance, simple production process, low pollution and reasonable price. Packaging and printing of food, medicine, daily light industry, clothing, cigarettes and other products.
2.Status of EVA industry
EVA is a solid fusible copolymer composed of ethylene (E) and vinyl acetate (VA). The higher the content of vinyl acetate (VA content), the more transparency, softness and toughness it will have. High, and the lower the melting point. According to different VA content, EVA products can be divided into foaming grade, wire and cable grade, coating grade, hot melt grade and other different levels. Applications include packaging, adhesives, printing, wire and cable, footwear and clothing. In thermal lamination film production, coating grade EVA is a commonly used hot melt adhesive which is combined with a substrate during heating and pressurization to form a thermal lamination film product.
3.Status of BOPET industry
BOPET film (or polyester film) is a film material made of polyester (ie, polyethylene terephthalate), which is made into a thick sheet by extrusion and then biaxially stretched. Used as a substrate in film production. BOPET film is a colorless, transparent and lustrous film with excellent mechanical properties, high rigidity, hardness and toughness, puncture resistance, friction resistance, high temperature and low temperature resistance, chemical resistance, oil resistance, air tightness and fragrance. It is one of the commonly used barrier composite film substrates.
The main factors affecting the profit level of the thermal lamination film industry are:
First, changes in the prices of raw materials and products. Both have a very close relationship with crude oil prices, and changes in crude oil prices will be transmitted downstream along the industrial chain. However, it is advantageous for the thermal lamination industry that thermal lamination films typically have a small percentage of the total cost of downstream products, and downstream users have lower demand elasticity, even if thermal lamination film manufacturers increase their upstream raw material prices. Price increases, downstream printing companies and distributors will not reduce the amount of thermal lamination film for this purpose, thermal lamination film manufacturers can effectively transfer cost pressure to the downstream, and thus ensure their own profit margins. On the other hand, the thermal lamination film raw materials are in a state of oversupply, which is a fully competitive market. thermal lamination film companies have strong bargaining power for low-end raw material suppliers.
Second, technological progress. In general, leading thermal lamination companies can reduce production costs and increase profit margins by developing new technologies. However, when advanced technology is gradually mastered by most companies, the level of profitability will be re-rated to average.