Packaging bags are used to encase various products, facilitating transportation and storage throughout the production and distribution processes. They are widely employed in both everyday life and industrial manufacturing. Based on their manufacturing processes, they are commonly categorized into plastic packaging bags and composite packaging bags. Composite packaging materials are designed to enhance key properties such as air permeability, moisture resistance, oil resistance, water resistance, and chemical resistance, while also providing protection against insects, dust, microorganisms, and odors—such as light, fragrance, and unpleasant smells. Additionally, these materials offer improved heat and cold resistance, impact resistance, superior mechanical strength, and enhanced processability, along with excellent printability and decorative appeal.

Instant noodles: The primary structures are BOPP 18/VMCPP 25, BOPP 18/CPP 20, and BOPP 18/PE 20. The packaging method is standard automatic roll‑film packing, with requirements for oil resistance, moisture barrier properties, cost‑effectiveness, and high‑temperature compatibility.

Puffed foods: The primary material structure is BOPP 18/VMCPP 25, or BOPP 18/VMPET 12/PE 40. The packaging method is inflatable packaging, with requirements for airtightness, light‑blocking properties, and oil resistance.

Candy, biscuits, vermicelli, dried foods, and dried fruits: the primary material structure is OPP/CPP or OPP/VMCPP; packaging is carried out either manually or via automatic film‑roll wrapping; packaging requirements include transparency, gloss, aesthetic appeal, and cost‑effectiveness.

Liquid detergents and cream‑type products: The primary material structures are PET/VMPET/PE, PET/AL/PE, and PET/PA/PE. Packaging is typically performed via automated liquid filling, with key requirements including resistance to contamination, light‑blocking properties, airtightness, and high mechanical strength.

Oil pouches and soy sauce pouches: The primary material structures include PET/PE, PA/PE, PA/CPP, and PET/CPP. The packaging method is automated liquid filling, with requirements for contamination resistance, pressure resistance, high-speed processing, and strong heat-seal strength.

Coffee, tea, and seasoning powders: The primary material structures are PET/VMPET/PE, PET/AL/PE, OPP/VMPET/PE, and OPP/AL/PE. Packaging methods include conventional manual and automated vacuum sealing. Packaging requirements encompass aroma retention, light shielding, gas tightness, antistatic properties, and resistance to contamination.

Meat and fish products: The primary material structures are PA/PE and PET/PE, with vacuum‑packed and frozen packaging methods. Packaging requirements include barrier properties, puncture resistance, heat‑seal strength, and heat resistance.

Liquid stand-up pouches: The primary material structures include PET/AL/PET/PE, PET/AL/NY/PE, BOPP/NY/PE, and PET/PE. The packaging process is automated filling, and the packaging must meet requirements for barrier properties, pressure resistance, heat resistance, puncture resistance, and contamination resistance.

Steam‑cooked foods: The primary material structures are PET/RCPP, PA/RCPP, and PET/AL/NY/RCPP. The packaging process involves high‑temperature sterilization at 121–135°C. Packaging requirements include high heat‑seal strength and excellent heat resistance.

Rice and rice-based products: The primary material structure is PA/PE. The packaging method is vacuum-sealed, with the following requirements: high tensile strength, low-temperature heat sealing, and excellent transparency.