Difference and identification between OPP film and PET film

OPP film and PET film are two commonly used types of plastic films with distinct characteristics. Here are the key differences and ways to identify them:

1. Material Composition:

   - OPP Film (Oriented Polypropylene): OPP film is made from polypropylene, a thermoplastic polymer. It is known for its clarity, high tensile strength, and moisture resistance.

   - PET Film (Polyethylene Terephthalate): PET film is made from polyethylene terephthalate, another thermoplastic polymer. It is known for its strength, durability, and excellent dimensional stability.

2. Transparency and Clarity:

   - OPP Film: OPP film is typically transparent, offering good clarity and allowing for the visibility of products packaged within it.

   - PET Film: PET film is also transparent and provides excellent clarity, making it suitable for applications where the visibility of packaged items is important.

3. Mechanical Properties:

   - OPP Film: OPP film has good tensile strength, flexibility, and resistance to tears or punctures. It is often used for packaging applications that require resistance to stress or deformation.

   - PET Film: PET film has higher tensile strength and stiffness compared to OPP film. It offers excellent dimensional stability and is often used for applications that require rigidity and resistance to temperature variations.

4. Heat Resistance:

   - OPP Film: OPP film has moderate heat resistance, withstanding temperatures typically up to around 120-140°C (248-284°F) before melting or deforming.

   - PET Film: PET film has better heat resistance compared to OPP film. It can withstand higher temperatures, typically up to around 160-180°C (320-356°F) without significant deformation.

5. Applications:

   - OPP Film: OPP film is commonly used in various packaging applications, such as food packaging, label protection, adhesive tape, and wrapping films.

   - PET Film: PET film finds applications in industries like electronics, photography, graphic arts, solar panels, medical devices, and food packaging that require higher strength, rigidity, and heat resistance.

Identification:

To identify the difference between OPP film and PET film, you can consider the following factors:

   - Look for the labeling or product specifications provided by the manufacturer or supplier.

   - Observe the film's characteristics, such as its stiffness, heat resistance, and transparency.

   - Check the recycling code, if available. OPP film is typically labeled with the recycling code "5" (polypropylene), while PET film is labeled with the recycling code "1" (polyethylene terephthalate).

It's important to note that different variations of OPP and PET films exist, and their properties can vary based on specific manufacturing processes or additives used. When in doubt, consulting the manufacturer or supplier is recommended to ensure accurate identification and selection of the appropriate film for your specific application.