Introduction of several advantages of precoating film
First, since no harmful substances are produced during the precoating process, the precoating process is more environmentally friendly.
Second, the precoating and laminating process is simple, and it is not necessary to mix the glue liquid like the film coating and laminating process before production. It is also unnecessary to control the amount of glue in the production process, and it is unnecessary to dry the adhesive. It only needs to control the temperature, pressure and speed, and the shutdown process is relatively simple, without cleaning the gluing mechanism.
Third, there will be no bubbles, wrinkles, film stripping and other phenomena in the production, so the quality of the film-coated products is higher.
Fourth, it can adapt to a wide range of film covering equipment. It can use pre-coating film covering equipment or film coating equipment, and it can also use plastic packaging equipment.
Fifthly, since there is no combustible substance such as organic solvent in the pre-coating process, it can effectively prevent the occurrence of fire accidents in production, with a higher safety factor.
Sixth, high production efficiency.
Why is the instant film coating method still widely used in China at present?Although the comprehensive performance of the precoating method is better than the instant film coating method, the current situation of the domestic film coating industry shows that the vast majority of domestic enterprises are still using the instant film coating technology. The main reasons can be summarized as follows.
First, the precoating technology started relatively late in China.
Second, the production of pre-coating film has high technical content, complex process and large equipment investment, and the general enterprises are unable to invest in the pre-coating film production line.
Third, due to China's surplus labor resources and low labor costs, the material cost accounts for a large proportion of the comprehensive cost of the film covering process. The cost of precoating is higher than that of instant coating, which will inevitably affect its application.
Fourth, most of the equipment produced by domestic film-coating equipment manufacturers are film-coating equipment.
Fifthly, although the Chinese government emphasizes the environmental protection of the industry, the laws and regulations specifically for the film covering industry need to be improved.
That is, the common point of blistering and film stripping of the film-coated products processed by the gluing wet composite process is that the film breaks away from the substrate of paper and printing, and damages the compactness and smoothness of the paper/plastic composite.
To improve the wear resistance of biaxially oriented polypropylene membrane (BOPP membrane), a novel polypropylene surface modification coating with good transparency and wear resistance was prepared by sol-gel method, using silane coupling agent (KH550), aluminum sec butanol (ASB) and ethyl orthosilicate (TEOS) as precursors, solid acid (p-toluene sulfonic acid) as catalyst
The printing and film are combined by professional laminating equipment to form a paper-plastic product. This technology is called lamination. The surface of the printed matter coated with film is brighter and smoother, the pattern is more bright, and the performance of wear resistance, folding resistance, tensile resistance, moisture resistance, chemical corrosion resistance and other properties are also enhanced. Even some apparent defects in the printing process can be largely compensated. Therefore, not only the service life is extended, but also the beauty of the product is greatly improved. Since the film coating technology was born in the 1950s, the film coating technology has experienced three important development stages:solvent-based coating technology, water-soluble coating technology, and precoating technology.
Precoating film refers to the process of laminating plastic film with paper print after pre-gluing and rewinding. The precoating film structure is composed of substrate and adhesive layer. According to different substrates, the precoating film can be divided into BOPP precoating film, BOPET precoating film and BOPA precoating film. The adhesive layer is mainly EVA hot melt adhesive and LDPE hot melt adhesive. Downstream mainly applies to the packaging of books, food, medicine, daily necessities and other products in the field of industrial printing, digital printing, card certification, anti-counterfeiting, commercial advertising and construction materials in the special products market in the field of commercial printing.