What is BOPP?

BOPP is the abbreviation for Biaxially Oriented Polypropylene, which stands for biaxially oriented polypropylene film. It is a very important flexible packaging material. The following is a detailed introduction to BOPP:

1、 Production process

The production process of BOPP film is to first make a sheet or thick film from the melt of polymer polypropylene through a narrow machine head, and then stretch it in two vertical directions (longitudinal and transverse) simultaneously or step by step in a dedicated stretching machine at a certain temperature and set speed, and then make the film through appropriate cooling or heat treatment or special processing (such as corona discharge, coating, etc.).

2、 Performance characteristics

Physical stability: Due to the orientation of stretching molecules, BOPP film has good physical stability.

Mechanical strength: It has high tensile strength, impact strength, rigidity, and toughness.

Airtightness: Excellent airtightness can effectively block gases.

Transparency and glossiness: High transparency and glossiness make the appearance of the product more beautiful.

Durable and wear-resistant: The film is durable and wear-resistant, with a long service life.

Non toxic and harmless: BOPP film is colorless, odorless, tasteless, and non-toxic, and can be directly used in situations where it comes into contact with food and drugs.

3、 Main drawbacks

The main disadvantage of BOPP film is poor heat sealing performance, which makes it difficult to seal when used independently. Therefore, the outer film commonly used as a composite film, such as when combined with polyethylene film, has ideal moisture resistance, transparency, strength, stiffness, and printability, making it suitable for storing dry food.

4、 Surface treatment

Due to the non-polar surface, high crystallinity, and low surface free energy of BOPP film, its printing performance is poor and its adhesion to ink and adhesives is poor. Before printing and lamination, it is necessary to perform surface treatment on BOPP film to improve its printing and lamination performance.

5、 Classification and Application

According to different uses, BOPP film can be divided into various types, such as regular type, heat sealed type, cigarette packaging film, pearl film, metalized film, matte film, etc. These different types of BOPP films have a wide range of applications in packaging, printing, lamination, and other fields. For example:

Ordinary BOPP film: used for printing, lamination, coating (adhesive tape and PVDC coated film base film), etc., it is the most widely used and high-yield variety of film products.

BOPP heat sealing film: used for ordinary packaging, such as cigarette packaging film, three-layer heat sealing film, five layer gas barrier film, etc.

BOPP pearl film: With a satin like texture, pearl luster, low density, excellent flatness, and gas barrier properties, it can be widely used for direct packaging of dried fruits, ice cream, candies, high-end soap, gifts, and more.

In summary, BOPP film is a high-performance and widely used flexible packaging material. With the continuous development of the packaging industry and the increasing demand for environmental protection, BOPP film will continue to play an important role in the future.