Plastic has become an indispensable material in our daily lives due to its durability, flexibility and low production cost. However, a large amount of plastic waste is also generated every year and plastic films make up a significant portion. As plastic films are lightweight and flexible, they are widely used in packaging, agricultural industry and many other fields. But due to their lightweight nature, plastic films are often considered not recyclable and many end up in landfills or oceans. This causes severe environmental pollution. Therefore, recycling plastic films has become an important issue globally.
Plastic films refer to thin and flexible plastic sheets made primarily from polyethylene (PE) and polypropylene (PP). Common plastic films include shopping bags, food packaging films, agricultural plastic films, plastic wraps and more. Based on density, PE plastic films can be divided into low-density polyethylene (LDPE) film and high-density polyethylene (HDPE) film. LDPE film is soft and flexible while HDPE film is stiff with higher melting point. Another major type is PP film which is tough, can be made transparent and is widely used in food packaging.
Recycling waste plastic films brings enormous economic and environmental benefits:
Conserves natural resources and reduces pollution - By recycling plastic films, less new raw materials need to be extracted from the earth and fossil fuel consumption for plastic production is lowered. This protects natural resources and reduces pollution.
Saves landfill space - Plastic films constitute a large portion of plastic waste. Recycling plastic films can significantly reduce the amount of waste going to landfills and prolong their lifespan.
Energy savings - The production of recycled plastic requires only 30-80% of the energy needed to produce virgin plastic from crude oil. This leads to huge energy savings.
Creates jobs and grows green economy - The plastic recycling industry provides many jobs in collection, sorting and reprocessing of plastic waste. It stimulates the development of green economy.
Generates revenue - Recycled plastic films can be converted into useful products or sold to plastic manufacturers. This generates additional revenue for waste management agencies and recycling companies.
The basic steps to recycle plastic films at consumer and industrial levels are:
Collection: Collect clean and dry plastic film waste from households, retailers, manufacturers etc separately from other trash.
Sorting: Different kinds of plastic films like PE, PP or multilayer films need to be sorted either manually or with automated sorting machines.
Shredding/baling: The sorted plastic films go through shredding or baling to reduce volume and prepare for transport.
Washing: Contaminated plastic scraps may require washing to remove residues before processing.
Reprocessing: The shredded plastic is melted and remolded into plastic pellets or sheets for new products through extrusion or injection molding.
Manufacturing: The recycled plastic pellets or sheets are used to manufacture various useful products like benches, traffic cones, pipes, outdoor furniture etc.
While plastic film recycling holds huge promise, there are also several challenges:
Difficult to collect due to small size - Being lightweight and flexible, plastic films are blown away easily and not readily separated from garbage for collection.
Contamination issues - Oil, food residues and other contaminants on plastic films lower their recycling value. Proper cleaning is needed.
Lack of sorting infrastructure -sorting facilities for plastic films lag behind other plastics like bottles due to technical difficulties in handling thin films.
Limited end markets - There is lack of stable end market demand for recycled plastic films to fully utilize the collected volumes.
High transportation costs - Transporting low-density plastic films over long distances increases costs.
Consistency in quality - Maintaining consistent quality of recycled plastic films is challenging due to mixed compositions.
Public education - More awareness campaigns are needed to encourage the public to adopt plastic film recycling habit.
However, continuous efforts are being made worldwide to address these challenges through innovations and partnerships among stakeholders.
To efficiently collect, sort and process plastic films, appropriate machinery solutions are essential. Some suitable machines include:
Bag drop-off boxes: Secure collection boxes allow plastic film dropoff at retailers.
Automated sorting lines: Sensor-based lines accurately sort films by resins using near-infrared technology.
Film densifiers: Compact films into dense bales via vacuum pressing, reducing transport costs.
Shredders: Cut films into uniform flakes for cleaning and melting.
Wash lines: Powerful washers effectively remove contaminants using water, heat and chemicals.
Milling/extruding systems: Convert cleaned flakes into nurdles or rods for new product manufacture.
Injection molding machines: Shape nurdles into useful plastic items using heat and pressure.
Quality testing equipment: Ensure recycled plastic meets standards using FTIR, density and contaminant check.
Choosing appropriate modern machinery tailored to your plastic film type and volumes will boost recycling efficiency and product quality.
In summary, plastic film recycling holds immense promise for a sustainable future if challenges are addressed through technology innovations, cooperation among stakeholders and public participation. With growing policy support and investment worldwide, recycling of PE, PP and other plastic films can be scaled up significantly. This would help reduce environmental pollution while facilitating circular economy. More efforts are still needed to close the plastic film recycling loop and realize its full potential.
