Recycled polypropylene (rPP) resin-made biaxially oriented polypropylene (BOPP) films lead the green revolution in the packaging industry.
With the intensification of global efforts in plastic pollution control, recycled plastic technology has become a key driver of the circular economy. Recently, biaxially oriented polypropylene (BOPP) films made from recycled polypropylene (rPP) resin have drawn significant attention within the industry. This new type of environmentally friendly material not only maintains the high transparency, mechanical strength, and barrier properties of traditional BOPP films but also significantly reduces carbon emissions through recycling technology, providing a new sustainable development path for the packaging industry.
Technical Breakthrough: The Perfect Combination of rPP and BOPP
Traditional BOPP films, using polypropylene (PP) as the raw material, possess advantages such as light weight, water resistance, and high barrier properties, and are widely applied in fields like food, medicine, and electronics. However, as a petroleum-based material, the production process of PP consumes a large amount of energy and is difficult to degrade. Recycled polypropylene (rPP) is produced through processes such as cleaning, pelletizing, and modification of discarded PP products (such as plastic bottles and films), which not only retains the excellent properties of PP but also achieves the recycling of resources.
In terms of the production process, rPP-BOPP films adopt the same biaxial orientation technology as traditional BOPP. By stretching both longitudinally and transversely, the directional arrangement of molecular chains is enhanced, and the tensile strength of the film (longitudinal ≥ 120MPa, transverse ≥ 200MPa) and transparency (turbidity ≤ 1.5%) are improved. It is worth noting that the introduction of rPP resin requires the optimization of the extrusion system. For example, a twin-screw extruder is used to improve the uniformity of the melt, and online detection technology is employed to calibrate parameters in real time, ensuring that the thickness tolerance of the film is controlled within ±0.1μm.
Market Prospects: Dual Driving Forces of Policies and Demands
In terms of policies, China's "14th Five-Year Plan for the Development of Circular Economy" clearly supports the recycled plastic industry and provides tax incentives for eligible rPP production enterprises. The European Union's "Single-Use Plastics Directive" also requires that the proportion of recycled materials in packaging plastics reach 25% by 2025, further stimulating the market demand for rPP-BOPP.
Regarding market demand, the demand for environmentally friendly materials in fields such as food packaging, electronic labels, and pharmaceutical packaging continues to grow. According to predictions by industry analysis institutions, the global BOPP film market size will grow at a compound annual growth rate (CAGR) of 5.3%. Among them, the proportion of rPP-BOPP will increase from 8% in 2023 to 15% in 2028.
Technical Challenges and Solutions
Despite the promising prospects of rPP-BOPP films, their promotion still faces challenges.
For instance, the control of impurities in recycled PP, color consistency, and thermal stability need further optimization. In response to these issues, enterprises are breaking through the bottlenecks through the following measures:
Raw Material Pretreatment: Multistage screening and near-infrared sorting technologies are adopted to remove impurities such as metals and paper, ensuring the purity of rPP resin.
Modification Technology: Compatibilizers and antioxidants are added to improve the interfacial bonding between rPP and virgin PP, enhancing the thermal stability of the film.
Process Optimization: Intelligent temperature control systems and online detection devices are introduced to monitor the melt temperature and draw ratio in real time, reducing product defects.
