How to distinguish PP, OPP, BOPP bags
Jul 31, 2023
How to distinguish PP, OPP, BOPP bags
When it comes to plastic packaging, the food industry mainly uses BOPP bags or films. BOPP bags are easy to coat, print and laminate, making them ideal for packaging products such as snacks, fresh produce and confectionery. Parallel to BOPP, there are also PP and OPP bags for packaging in the market. Of the three bags, polypropylene is common and is the basic polymer from which these bags are made. PP stands for polypropylene, OPP stands for oriented polypropylene, and BOPP stands for biaxially oriented polypropylene. They are made in different styles.
Polypropylene, also known as polypropylene, is a semi-crystalline thermoplastic polymer. It has high impact resistance and is strong and tough. Popular packaging bags such as zipper pouches, stand-up pouches and spout pouches are made from polypropylene. At first glance, it can be difficult to distinguish PP, OPP and BOPP plastics. However, the difference can be felt by touch, OPP feels brittle while PP is softer.
The best way to differentiate PP, OPP and BOPP bags is to understand their use in real world objects. Non-woven bags use polypropylene bags or PP bags. These are treated to make them absorbent or hygroscopic. Sanitary napkins, diapers, air filters, etc. are some common PP products. The same material is also used to make thermal clothing because they can provide a temperature barrier.
OPP bags have high tensile strength and are transparent in color. They can withstand high temperatures but will wrinkle if used roughly. Scotch tape is also made with the same formula. OPP bags are not easy to tear and are used for packaging of leather products, clothing, etc.
BOPP bags are crystal clear polyethylene bags. Their manufacturing process (i.e. biaxial orientation) gives them a transparent appearance, which makes them suitable for branding by printing on their surface. BOPP bags are mainly used for retail packaging. Biaxial orientation increases their strength so they are better suited to carry greater loads. BOPP bags are waterproof. The product inside them will resist moisture for a longer period of time. That's why they are the most ideal choice for the cloth packaging industry.
Polypropylene derivatives namely PP, OPP and BOPP are resistant to organic solvents, acids and bases. This is why they are widely used in the packaging industry, since transportation and storage in changing atmospheres is inevitable. Like plastic wrap, they protect products from moisture and dust. They are recyclable and have a lower carbon footprint in their manufacture. So from an environmental point of view, PP, OPP, BOPP bags are all sustainable choices.
