BOPET classification and application

Polyester film is a high-grade film made from high-quality fiber-grade polyester chips (viscosity 0.64) as the main raw material, using advanced technological formulas, and undergoing drying, melting, extrusion, casting and stretching.

The characteristics of polyester film determine its different uses. Polyester films for different uses have different requirements for raw materials, additives and processing techniques, and their thickness and technical indicators are also different。

1. Electrical insulation film. Because it has good electrical, mechanical, thermal and chemical inertness, good insulation properties and high breakdown voltage, it is specially used for electronic and electrical insulation materials. Commonly used standard thicknesses are: 25μm, 36μm, 40μm, 48μm, 50μm, 70μm, 75μm, 80μm, 100μm and 125μm (micron). These include wire and cable insulation film (thickness 25-75μm) and touch switch insulation film (50-75μm).

2. Capacitive film. It has the characteristics of high tensile strength, high dielectric constant, low loss factor, good thickness uniformity, good electrical properties, high resistance, etc., and has been widely used as capacitor dielectric and insulation barrier. Commonly used standard thicknesses are 3.5μm, 3.8μm, 4μm, 4.3μm, 4.8μm, 5μm, 6μm, 8μm, 9μm, 9.8μm, 10μm, 12μm.

3. Card protective film. It has good transparency, high stiffness, good thermal stability, smooth surface, excellent winding performance, uniform longitudinal and transverse stretching properties, and has excellent properties such as waterproof, oil-proof and chemical-proof. It is specially used for the protective packaging of pictures, certificates, documents and office supplies, making it smooth and beautiful after being hot-stamped as a protective film, while maintaining the clarity and non-deformation of the original. Commonly used standard thicknesses are 10.75 μm, 12 μm, 15 μm, 25 μm, 28 μm, 30 μm, 36 μm, 45 μm, 55 μm, 65 μm, and 70 μm. Among them, those above 15 μm are mainly used as laser anti-counterfeiting base films or high-end card protective films.

4. Universal membrane. It has excellent strength, dimensional stability, cold resistance and chemical stability, and is widely used in various substrates such as composite packaging, photosensitive film, metal evaporation, audio and video recording, etc. Specifically, there are the following types:

① Semi-reinforced membrane. The most important feature is that it has high longitudinal tensile strength and is not easy to break under large tensile forces. It is mainly used for packaging seals of boxed items. Commonly used standard thicknesses are 20μm, 28μm, 30μm, 36μm, and 50μm.

②Hot stamping film. The biggest features are good tensile strength and transparency, stable thermal properties, and low binding force with certain resins. It is mainly suitable for small size changes during high-temperature processing or as a transfer carrier. Conventional standard thicknesses are 9μm, 12μm, 15μm, 19μm, 25μm, and 36μm.

③Printing composite packaging film. The main features are good transparency, good penetration resistance, superior chemical resistance, temperature resistance and moisture resistance. Suitable for packaging of frozen food and food, pharmaceuticals, industrial products and cosmetics. Commonly used standard thicknesses are 12μm, 15μm, 23μm, and 36μm.

④Aluminized film. The main characteristics are high strength, good temperature and chemical resistance, good processing and anti-aging properties, and appropriate corona treatment makes the adhesion of the aluminum layer and the film stronger. After being used for aluminum plating, it can be widely used for packaging of tea, milk powder, candy, biscuits, etc. It can also be used as a decorative film such as flower string crafts and Christmas trees; it is also suitable for printing lamination or cardboard lamination. Conventional standard thicknesses are 12μm, 16μm, 25μm, and 36μm.

⑤Magnetic recording film. It has the characteristics of good dimensional stability, uniform thickness and high tensile strength. Suitable for base films and special packaging films for magnetic recording materials. Including audio and video tape base (commonly used standard thickness is 9-12μm) and black film (commonly used standard thickness is 35-36μm).