PET film is a kind of packaging film with comprehensive performance. It has good transparency and luster; It has good air tightness and fragrance retention; The moisture resistance is medium, and the moisture permeability decreases at low temperature. The mechanical properties of PET film are excellent, and its strength and toughness are the best among all thermoplastics. The tensile strength and impact strength are much higher than those of ordinary films; It has good stiffness and stable size, and is suitable for secondary processing such as printing and paper bags. PET film also has excellent heat resistance, cold resistance, chemical resistance and oil resistance. But it is not resistant to strong alkali; It is easy to carry static electricity, and there is no proper anti-static method. Therefore, attention should be paid when packaging powdery goods.
Advantages of PET film
① Close fitting and transparent, reflecting the product image.
② Tight package, good dispersion resistance.
③ Rain proof, moisture-proof and mildew proof.
④ No resiliency, with certain anti-counterfeiting function.
Type of PET film
one
PET high brightness film
In addition to the excellent physical and mechanical properties of ordinary polyester film, the film also has excellent light.
two
PET film
Scientific properties, such as good transparency, low haze and high gloss. It is mainly used for high-grade vacuum aluminized products. The film is a mirror after aluminized, which has a good packaging and decoration effect; It can also be used for laser anti-counterfeiting basement film, etc. High bright BOPET film has large market capacity, high added value and obvious economic benefits.
three
PET transfer film
Transfer film, also known as heat transfer printing film, is characterized by high tensile strength, good thermal stability, low thermal shrinkage, smooth and clean surface, good peeling property, and can be used repeatedly. It is mainly used as the carrier of vacuum aluminum plating, that is, after the PET film is placed in the vacuum aluminum plating machine for aluminum plating, it is coated with glue and compounded with paper, and then the PET film is peeled off, and the aluminum molecular layer is transferred to the surface of the paperboard through the adhesive effect, forming the so-called aluminized paperboard. The production process of aluminized paperboard is as follows:
PET base film → release layer → color layer → aluminum coating → adhesive coating → transfer to paperboard.
Vacuum aluminized paperboard is a kind of paperboard with metallic luster, which is a new advanced packaging material developed in recent years. This kind of aluminized cardboard has bright color, strong sense of metal and bright and elegant prints, which can replace the large area gilding of prints and play a role in beautifying the goods. As it adopts the method of vacuum aluminum plating, only a layer of 0.25 is covered on the card surface μ m~0.3 μ M The thin, compact and bright aluminum layer is only 1/500 of the aluminum foil layer of aluminum paperboard, so it not only has a noble and beautiful metal texture, but also has degradable and recyclable environmental properties. It is a green packaging material.
four
PET reflective film
PET reflective film is characterized by its excellent optical performance, smooth and clean surface, good thermal stability, small shrinkage and light aging resistance.
Reflective materials used in transportation facilities include lens type directional reflective film and flat top reflective film. Both of them use aluminized PET film as reflective layer. After being coated with pressure-sensitive adhesive, a number of glass beads with a refractive index of 1.9 are adhered to PET aluminized film, and then a layer of butyraldehyde surface protective layer is sprayed.
PET reflective film shall be applied to billboards with reflective requirements, traffic reflective signs (reflective road signs, reflective separation strips, reflective vehicle number plates), reflective police uniforms, industrial safety signs, etc.
five
PET chemical coating film
In order to improve the surface properties of PET film, improve the adaptability of printing and the adhesion of vacuum aluminum coating, corona treatment is usually used to increase the surface tension of the film. However, the corona method has some problems such as timeliness, especially in the high temperature and humidity environment, the film tension after corona treatment is easy to decay. However, the chemical coating method does not have such a problem, so it is favored by the printing industry and aluminum plating industry. Domestic enterprises have developed a series of PET chemical coating products: for example, water soluble polymer coating can improve the surface tension of PET film; Coating with acrylate emulsion can improve the adaptability of printing (water-soluble ink can be used); The coating with polyurethane aqueous solution can strengthen the adhesion between aluminum coating and PET base film, and increase the thickness of aluminum coating.
In addition, the coating method can also be used to prepare high resistance membranes and anti-static membranes.