The physical properties of packaging paper include thickness (0.05-0.2 mm) and basis weight (50-300 g/m²). Thicker papers, such as kraft paper, can withstand greater impact. Tensile strength can reach over 70 N/15 mm, suitable for packaging heavy items, while paper that is less prone to cracking during high-frequency folding is more suitable for gift bags and other packaging that requires repeated opening and closing. In terms of chemical and functional properties, waterproof packaging paper has a water vapor transmission rate of less than 5 g/m²·24h, suitable for seafood and frozen food packaging; aluminum foil composite paper has an oxygen transmission rate of <1.5 cc/m²·24h, effectively extending the shelf life of food. Food-grade packaging paper must pass FDA or GB 4806.8-2022 testing, and the heavy metal content (such as lead) must be ≤3 mg/kg.
Regarding environmental performance, environmentally friendly packaging paper must degrade by more than 90% within 180 days. PLA coated paper has a degradation rate of 95%, while FSC-certified paper reduces carbon emissions by 30% per ton compared to traditional processes. Future trends include high strength, multi-functionality, and low pollution, such as the 200% increase in tensile strength of novel nanocellulose-reinforced paper.
