PET film is a kind of packaging film with relatively comprehensive performance. PET film has excellent mechanical properties, its toughness is the best among all thermoplastics, and its tensile strength and impact strength are much higher than general films; it has good stiffness, stable size, and is suitable for secondary processing such as printing and paper bags, etc. PET film also has excellent heat resistance, cold resistance and Good chemical resistance and oil resistance. However, it is not resistant to strong alkali; it is easy to carry static electricity, and there is no proper method to prevent static electricity, so attention should be drawn to it when packaging powdery goods.

　　PET film types

　　PET high-gloss glossy film.

　　This film has excellent light in addition to the excellent physical and mechanical properties of ordinary polyester film.

　　PET film.

　　Academic properties, such as good transparency, low haze and high gloss. It is mainly used for high-grade vacuum aluminized products, the film is mirrored after aluminizing, which has good packaging decoration effect; it can also be used for laser laser anti-counterfeiting base film, etc. High gloss BOPET film has large market capacity, high added value and obvious economic benefits.

　　PET transfer film.

　　Transfer film is also called thermal transfer film. This transfer film is characterized by high tensile strength, good thermal stability, low thermal shrinkage, flat and smooth surface, good peelability, and can be used repeatedly. It is mainly used as a carrier for vacuum aluminizing, that is, after the PET film is aluminized in the vacuum aluminizing machine, it is coated with adhesive and laminated with paper, and then the PET film is peeled off, and the aluminum molecular layer is transferred to the surface of cardboard through the adhesive effect, forming the so-called aluminized cardboard. The production process of aluminized cardboard is:

　　PET base film → release layer → color layer → aluminized layer → adhesive coated layer → transfer to cardboard.

　　Vacuum aluminized cardboard is a kind of metallic luster cardboard, which is a kind of advanced novel packaging material developed in recent years. This kind of aluminized cardboard has bright color, strong metallic sense and bright and elegant printing, which can replace the large area of printed materials with hot stamping and play a role in the beautification of goods. Because it adopts the method of vacuum aluminizing, the surface of the cardboard is only covered with a thin and tightly shiny aluminum layer of0.25μm~0.3μm, which is only one fifth of the aluminum foil layer of the laminated aluminum cardboard, so that it has both noble and beautiful metallic texture, but also has degradable and recyclable environmental protection properties, and is a green packaging material.

　　PET reflective film.

　　PET reflective film is characterized by film with excellent optical properties, flat and smooth surface, good thermal stability, small shrinkage rate and light aging resistance.

　　There are two kinds of reflective materials used in traffic facilities: lens-type directional reflective film and flat-top reflective film, both of which use aluminized PET film as the reflective layer, on which a number of glass beads with refractive index of 1.9 are adhered to the PET aluminized film after being coated with pressure-sensitive adhesive, and then sprayed with a layer of acetal surface protection layer.

　　PET reflective film is used in reflective billboards, traffic reflective signs (reflective road signs, reflective barrier, reflective number plates), reflective police uniforms, industrial safety signs, etc.

　　PET chemically coated film.

　　In order to improve the surface properties of PET films to improve the adaptability of printing and the bonding of vacuum aluminizing layer, corona treatment is usually used to improve the surface tension of the films. However, the corona method has problems such as timeliness, especially in high temperature and high humidity environments, and the tension of the corona-treated film can easily decay. The chemical coating method, however, does not have such problems and is favored by the printing and aluminizing industries. Some domestic enterprises have developed PET chemical coating series products: such as coating with water-soluble polymers, which can improve the surface tension of PET film; coating with acrylate emulsions, which can improve the adaptability of printing (water-soluble ink can be used); coating with polyurethane aqueous solution, which can strengthen the bond between the aluminized layer and PET base film and increase the thickness of the aluminized layer.

　　In addition, the coating method can also be used to produce high barrier film and anti-static film, etc.

　　PET anti-static film.

　　Today&39;s world has entered the information age, various frequencies and wavelengths of electromagnetic waves fill the whole earth space, these electromagnetic waves will produce different degrees of interference to unshielded sensitive electronic components, circuit boards, communication equipment, etc., causing data distortion and communication disorder. And electromagnetic induction and friction generated by static electricity on various sensitive components, instruments, certain chemical products, etc., such as the accumulation of electrostatic discharge due to packaging film, the consequences will be devastating, so the development of anti-static PET packaging film is also very important. The feature of antistatic film is that by adding some kind of antistatic agent to PET film, a very thin conductive layer is formed on the surface of the film and a continuous phase is formed to improve the surface conductivity so that the generated charge can be leaked as soon as possible. The surface specific resistance of the antistatic film is generally required to be ≤10of 9~11 times ohm.

　　PET heat sealing film.

　　PET film is a crystalline polymer, after stretching and orientation, PET film will produce a large degree of crystallization, such as its heat sealing, it will produce shrinkage deformation, so ordinary PET film does not have heat sealing performance. To a certain extent, the application of BOPET film is limited.

　　In order to solve the heat sealing problem, a three-layer co-extruded heat-sealable PET film has been developed by modifying PET resin and adopting a three-layer A/B/C die structure. Heat-sealable PET films can be used in a wide range of applications such as packaging and card protection films for various products.

　　PET heat shrink film.

　　Polyester heat shrink film is a new type of heat shrink packaging material. Because it is easy to recycle, non-toxic, tasteless, good mechanical properties, especially in line with environmental protection, polyester (PET) has become an ideal substitute for polyvinyl chloride (PVC) heat shrink film in developed countries.

　　However, ordinary polyester is a crystalline polymer, and ordinary PET film can only obtain a heat shrinkage rate of less than 30% after a special process. To obtain polyester films with higher heat shrinkage, they must also be modified. In other words, in order to prepare polyester films with high heat shrinkage, copolymerization modification of common polyester, i.e. polyethylene terephthalate, is required. The maximum heat shrinkage of copolymer-modified PET films can be up to 70% or more.

　　Characteristics of heat-shrinkable polyester film: it is stable at room temperature, shrinks when heated (above glass transition temperature), and is subject to more than 70% heat shrinkage in one direction.

　　PET film advantages.

　　① Transparent against the body, reflecting the image of goods.

　　②Tightly bundled wrapper, good anti-dispersion.

　　③Resistant to rain, moisture and mildew.

　　④No recovery, with certain anti-counterfeiting function.

　　Heat shrinkable polyester film is commonly used in convenience food, beverage market, electronic and electrical appliances, metal products, especially shrinkable labels are its most important application area. Because with the rapid development of PET beverage bottles, such as Coke, Sprite, various fruit juices and other beverage bottles need PET heat shrink film with it to do heat sealing labels, they belong to the same polyester class, is environmentally friendly materials, easy to recycle and reuse.

　　In addition to shrink labels, heat shrink polyester film has also been used in recent years for the outer packaging of daily commodities. Because it can protect the packaging items from impact, rain, moisture and rust, but also make the product with a beautifully printed outer packaging to win the user, while it can well show the good image of the manufacturer. At present, more and more packaging manufacturers are using printed shrink film to replace the traditional transparent film. Because printing shrink film can improve the appearance of the product grade, is conducive to product advertising, and can make a deep impression of the trademark brand in the hearts of consumers.