With the continuous development of the plastics industry, polymer materials have been widely used in various industries. Among them, PET (polyethylene terephthalate) and PETG (polyethylene terephthalate copolymer) films have attracted great attention from the market due to their unique properties and wide range of application fields.

Although they have similar names, there are significant differences in chemical structure, physical properties, and application range. This article will delve into the differences between PET and PETG films to help readers better understand and apply these two materials.

What is PET film?

PET film is a film material made of PET resin through processes such as extrusion, stretching and heat treatment. PET film has excellent mechanical properties, thermal stability and optical transparency, and is widely used in packaging, electronics, optics, printing and other fields.

What are the main characteristics of PET film?

The main characteristics of PET film include: high transparency, excellent mechanical strength, good heat resistance, and good gas barrier properties.

1. High transparency: The light transmittance of PET film is as high as over 90% and has good optical properties.

2. Excellent mechanical strength: PET film has high tensile strength and tear resistance, and can maintain stable mechanical properties in various environments.

3. Good heat resistance: PET film has a high heat distortion temperature and can be used for a long time in high temperature environments below 150°C.

4. Excellent chemical stability: PET film has good resistance to most chemicals and is not easily corroded by acids, alkalis and organic solvents.

5. Good gas barrier properties: PET film has excellent oxygen barrier and moisture barrier properties, which can effectively extend the shelf life of packaged items.

What is PETG film?

PETG film is a modified PET film made from the copolymerization of PET and EG (ethylene glycol). On the basis of maintaining the excellent characteristics of PET film, PETG film further enhances the toughness and processing performance of the material. PETG film is widely used in medical, packaging, printing, advertising and other fields due to its unique properties.

What are the main characteristics of PETG film?

The main properties of PETG films include: excellent transparency, excellent toughness, good processing properties, low-temperature heat sealability, and chemical resistance.

1. Excellent transparency: The light transmittance of PETG film is as high as over 92%, and the transparency is higher than that of PET film.

2. Excellent toughness: Compared with PET film, PETG film has higher impact strength and is not easy to break.

3. Good processing performance: PETG film is easy to process and can be processed through various methods such as thermoforming, injection molding, cutting, drilling, etc., and is not prone to cracks or damage during processing.

4. Low temperature heat sealability: PETG film can be heat sealed at lower temperatures and has high heat sealing strength, making it suitable for a variety of packaging applications.

5. Chemical resistance: PETG film has good resistance to a variety of chemicals and can be used in some corrosive environments.

What is the difference between PET and PETG film?

Although PET and PETG films are similar in many aspects, they have significant differences in chemical structure, physical properties and application fields.

1. Chemical structure:

    ● PET film is a thermoplastic polymer made from terephthalic acid and ethylene glycol through the polycondensation reaction. There is only one alcohol in its molecular structure, ethylene glycol.

    ● PETG film is copolymerized on the basis of PET by adding a certain proportion of EG. Due to the addition of EG, there are two alcohols in the molecular structure of PETG, namely ethylene glycol and EG, which makes the PETG film more flexible and lower processing temperature.

2. Physical properties:

    ● Transparency: PET film has high light transmittance, but PETG film has higher transparency, with a light transmittance of over 92%.

    ● Mechanical strength: PET film has higher tensile strength and tear resistance, while PETG film has higher impact strength and toughness.

    ● Heat resistance: PET film has a higher heat distortion temperature and can be used for a long time below 150°C; while PETG film has slightly worse heat resistance, but its low-temperature heat sealability is better.

    ● Processing performance: PET film has good processing performance, but PETG film has better processing performance and is suitable for more types of processing techniques.

3. Application areas:

    ● PET film is widely used in packaging, electronics, optics, printing and other fields due to its excellent mechanical strength, thermal stability and gas barrier properties. For example, PET film is often used to make food packaging bags, electronic component protective films, optical lenses, and printing substrates.

    ● PETG film is widely used in medical, packaging, printing and advertising fields due to its excellent transparency, toughness and processing properties. For example, PETG film is often used to make packaging materials for medical devices, highly transparent billboards, printed matter laminations, and some special-purpose packaging materials.

Market prospects for PET and PETG films

With the advancement of science and technology and the continuous expansion of application fields, the market demand for PET and PETG films continues to grow. According to data from market research institutions, the average annual growth rate of the global PET and PETG market is expected to be around 6%.

Conclusion

To sum up, PET and PETG films, as two important polymer materials, have shown strong vitality in various industries with their superior characteristics and wide range of applications. Although they have significant differences in chemical structure, physical properties and application fields, they all provide indispensable material options for their respective application fields.

Whether in the fields of packaging, electronics, medical or advertising and printing, PET and PETG films show great potential and unlimited possibilities.