Paper-plastic composite bags are packaging containers formed by laminating woven fabric-made from flat polypropylene (PP) or polyethylene (PE) filaments-with refined, specialized composite kraft paper using a high-temperature and high-pressure process. The kraft paper component typically utilizes imported Canadian white kraft paper or Russian yellow kraft paper, while the plastic layer is formed via the casting of PP granules. The paper layer features a basis weight of 25–80 g/m² and a moisture content of ≤0.4%. This product employs a composite structure consisting of either two layers (woven fabric + kraft paper) or three layers (woven fabric + film + kraft paper), thereby combining the moisture resistance inherent in plastic materials with the mechanical strength characteristic of kraft paper.
For standard industrial applications, the longitudinal tensile strength of these paper-plastic composite bags generally ranges from 15 to 30 MPa, while the transverse tensile strength is approximately 10 to 25 MPa. For heavy-duty applications, the longitudinal tensile strength can reach 30 to 50 MPa, with the transverse strength ranging from 25 to 40 MPa. The tear strength typically falls between 8 and 20 kN/m, reaching 20 to 40 kN/m for heavy-duty products. Compliant with the GB8946-2013 national standard, this product is available in six effective width specifications ranging from 450 mm to 700 mm. It is widely utilized for the moisture-proof and sealed packaging of bulk materials-typically in 25 kg unit sizes-across various sectors, including plastic raw materials, chemical products, and construction materials. During storage, the ideal ambient temperature is between 15°C and 25°C, with relative humidity ideally maintained within the range of 40% to 60%. During transportation and handling, precautions must be taken to prevent moisture exposure and avoid direct sunlight; furthermore, when using forklifts for transport, care must be taken to ensure that the forks do not come into contact with or puncture the bag body.
