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Navigating Plastic Recycling: Challenges, Innovations, and Regulations

SpecialChem – Aug 23, 2023

TAGS:  Sustainability and Bioplastics    

Recycling Plastics Plastic waste mounting over the face of our planet is a real crisis! Since plastics are ubiquitous in daily use as well as in high-end applications, there is a need to address this plastic pollution problem. That is where recycling comes up as a tangible solution providing an avenue to:

  • reduce waste,
  • conserve resources, and
  • lessen the environmental footprint of our plastic-dependent world.

Regulations banning or imposing fees on single-use plastic bags have been adopted by various countries such as France and Taiwan to encourage reusable alternatives. In the EU, the Packaging and Packaging Waste Directive (PPWD) requires that all packaging must be made of at least 30% recycled materials by 2030. These regulations make recycling a mandate and not an option anymore.

On top of that, according to a study by the University of California, Berkeley1, recycling plastic can reduce greenhouse gas emissions by up to 70% compared to making new plastic from oil. The study also found that recycled plastic can save up to 50% of the energy used to produce virgin plastic.

Read on and find out more about recycling & best methods to adopt:

  1. How to define plastic recycling?
  2. Can all plastics be recycled?
  3. Which is the best method for recycling plastics?
  4. Why additives are important in plastic recycling?
  5. What are the regulations that govern plastic recycling?


How to define plastic recycling?


The recycling process is different for pre-consumer and post-consumer materials:

  • Pre-consumer plastic recycling — It is the process of recycling plastic waste that is generated during the manufacturing process. This waste can include things like plastic scrap, offcuts, and rejects. Pre-consumer plastic is usually of a higher quality than post-consumer plastic, so it can be recycled into a wider range of products.

  • Post-consumer plastic recycling — It is the process of recycling plastic waste that has been used by consumers. This waste can include things like plastic bottles, bags, and packaging. Post-consumer plastic is often contaminated with other materials, such as food, dirt, and other debris. This can make it slightly difficult to recycle.

The specific recycling process for pre-consumer and post-consumer plastic varies depending on the type of plastic and the equipment available. However, the general steps involved are:

CollectionCollection and distribution — Post-consumer plastics are collected from homes, businesses, and institutions. This can be done by local government or private companies. Plastics can also be taken to designated recycling bins or facilities, ranging from bottle banks to larger waste sites.


Step 2 - SortingSorting and categorizing — In this step, recyclers separate different types of plastics from each other. They may also sort plastics based on properties like color, thickness, and use. Machines at the recycling plant handle this process to improve efficiency and prevent contamination of end products.


Step 3 - WashingWashing — Washing is a critical step to remove impurities that can hinder the recycling process or ruin a batch of recycled plastic. Impurities such as product labels, adhesives, dirt, and food residues are targeted. While plastics are often washed during recycling, it's important to minimize impurities even before disposal and collection.


Step 4 - ShreddingShredding — Plastic is fed into shredders to break it down into smaller pieces. These smaller pieces are more manageable for further processing and reuse. They can also be used for other applications without additional processing, like being added to asphalt or sold as raw material. Shredding helps identify any remaining impurities, including metal, which can be collected using magnets.


Step 5 - IdentificationIdentification and separation of plastics — In this step, the plastic pieces are tested for their class and quality. Density-based segregation is performed by floating the plastic particles in water, while "air classification" determines the thickness of the pieces. Thinner pieces float, while larger or thicker pieces sink.


Step 6 - Extruding in Recycling PlantExtruding and compounding — In this final step, the shredded plastic particles are transformed into usable products for manufacturers. The plastic is melted and crushed together to form pellets. It's important to note that not all types, classifications, and qualities of plastic can be processed at a single recycling plant. Different grades of plastic may be sent to other facilities for this final step.


Environmental benefits


  • Energy conservation: Recycling 1 ton of plastic saves approximately 5.774 kWh, equivalent to the energy consumed by two people in a year.
  • Reduced petroleum use: Recycling plastic waste has the potential to reduce oil consumption by up to 40%, saving 16.3 barrels of oil per ton of recycled plastic.
  • CO2 emission reduction: Recycling plastic leads to decreased CO2 and greenhouse gas emissions associated with the production of new plastics.
  • Reduced landfill use: Recycling reduces the amount of plastic in landfills, resulting in lower emissions of carbon dioxide and methane, which can cause environmental damage and public health issues.


Can all plastics be recycled?


Technically, every type of plastic can be recycled, but the actual recycling potential varies depending on economic and logistical considerations. The most commonly recycled plastics are polyethylene terephthalate (PET/PETE) and high-density polyethylene (HDPE), which are used in soft drink bottles and milk bottles. In addition to plastic packaging, durable plastics can also be recycled. The below table depicts the 7 most used recyclable plastics in the market.

Property PET HDPE LDPE PVC PP PS Other Plastics
Clarity
Clear Translucent Translucent Clear Translucent Clear  -
Moisture barrier
Fair to good Good to excellent Good Fair Good to excellent Poor to fair
Oxygen barrier
Good Poor Poor Good Poor Fair
Maximum temperature
120°F 145°F 120°F 140°F 165°F 150°F
Rigidity Moderate to high Moderate Low Moderate to high Moderate to high Moderate to high
Impact resistance Good to excellent Good to excellent Excellent Fair to good Poor to good Poor to good
Heat resistance Poor to fair Good Fair Poor to fair Good Fair
Cold resistance Good Excellent Excellent Fair Poor to fair Poor
Sunlight resistance Good Fair Fair Poor to good Fair Poor to fair
Common uses Soft drink bottles, food containers, clothing fabrics Plastic rulers, hula hoop rings, toiletry packaging containers, roadside curbs, benches, tables, cargo truck liners Flexible container lids, squeezable bottles, and frozen food bags Packaging containers, electricity installation cables, rigid pipes, credit cards, synthetic leather Reusable microwave containers, kitchen utensils, disposable food containers, soft drink bottles Disposable cups, trays, packing containers, egg cartons Polycarbonate, polylactide, etc., are used in baby milk bottles, riot shields, plastic toys, sunglasses lenses, automotive headlamps
Recycling information  It can be mechanically recycled wherein PET bottles are cleaned, shredded, and melted to form a new plastic resin. Chemical recycling is also explored from which high-quality recycled PET resin can be extracted.
Due to its rigidity, it is difficult to shred and melt. HDPE products are collected, separated, cleaned to remove contaminants, shredded, melted, and then molded into new products, such as bottles, crates, and toys.
The process is mostly similar to HDPE but its high flexibility makes it difficult to sort as it gets tangled up with substances. LDPE items are also more prone to contamination.
After collection, sorting, and cleaning, it is shredded into small pieces (flakes and granules). After that chlorine is removed chemically, then cleaned again to reprocess into new PVC materials.
After collection, sorting, cleaning and shredding, the shredded PP is melted at a high temperature and then extruded through a machine to create uniform plastic resin.
After collection, sorting, cleaning, and shredding, EPS foam especially is compacted or densified to reduce its volume. For this, the foam is melted & compressed into denser blocks. It is then extruded through a machine to create uniform plastic resin pellets.
Based on several factors such as rigidity or flexibility, it may be difficult or easy to recycle several plastics.
Recycling codes  PET Recycling Code  PE-HD Recycling Code  PE-LD Recycling Code  PVC Recycling Code  PP Recycling Code  PS Recycling Code  OTHer Plastics Recycling Code
Commercial recycled grades PET Grades HDPE Grades LDPE Grades PVC Grades PP Grades PS Grades -


Key challenges related to recycled plastics


While theoretically, the recycling of almost all plastic is possible, there exist various obstacles that impede this process. Regrettably, recycling is not always justifiable from environmental, economic, or technical standpoints. Here are some reasons that hinder the feasibility of recycling:

  • Complex composition: Frequently, items consist of multiple plastic types and layers, rendering their separation arduous and expensive, thereby compromising recyclability.

  • Contamination: Plastics often become tainted with food and other substances, rendering the resins insufficiently clean for reuse.

  • Costly recycling facilities: Constructing and operating recycling facilities necessitates significant financial investment, often amounting to millions of dollars. These facilities can only be financially viable when processing large quantities of plastic on a daily basis. Consequently, recycling small amounts of plastics becomes economically and practically unfavorable due to low efficiency and high costs.


Which is the best method for recycling plastics?


The traditional form of recycling is called "mechanical recycling", where plastics are physically broken down without altering their chemical structure. However, there is a newer method called "chemical recycling" that does modify the chemical structure of the plastic. This technology allows mixed batches of various plastic types to be recycled, including food-grade packaging.

Chemical recycling is an innovative approach in the plastic waste recycling sector, targeting plastics that are currently sent to landfill or incineration. It involves processes such as pyrolysis, catalytical and non-catalytical gasification, solvolysis, and hydrothermal treatment. These technologies offer the following benefits and advancements:

  • Successful application to PET, HDPE, polystyrene (PS), and nylon-6
  • Conversion of polymer waste back into monomers through pyrolytic, catalytic, or enzymatic depolymerization processes
  • Chemical separations are performed to refine the chemical feedstocks for reuse
  • Although energy-intensive and generating waste, it recirculates refined carbon in circular manufacturing systems for extended periods
  • The emergence of new chemically recyclable polymers, such as dynamic covalent polymer networks.

These newly emerged polymers feature dynamic covalent bonds and can be thermally processed like thermoplastics. They exhibit performance advantages similar to thermosets due to their networked architecture. Most of these polymers can be solvolyzed into small molecules or oligomers. However, the recovered monomers usually cannot be directly repolymerized into fully networked resins with similar properties, except for dynamic covalent polymer networks based on polydiketoenamines (PDKs). Furthermore, chemical recycling includes various specific technologies, such as:

  • Feedstock recycling — It converts mixed residual plastic waste into raw materials for steam-cracker feedstock and industrial waxes.
  • Depolymerization — It breaks down polymers into monomers.
  • Plastic to fuel — It is the process that generates fuels.

Chemical recycling contributes to higher recycling rates, allowing the petrochemical industry to produce new virgin quality and food-grade polymers with recycled content. It serves as a complementary solution to mechanical recycling for hard-to-recycle plastic waste, particularly films, multi-layered, and laminated plastics, providing an alternative to landfilling and incineration.


Advantages of chemical recycling over mechanical recycling


  • Separation of additives, fragrances, and dyes: Chemical recycling allows the separation of additives, fragrances, and dyes from the packaging material. This means that these elements can be effectively removed, leading to higher purity levels in the recycled material.

  • Separation of combined materials and plastics: Unlike mechanical recycling, chemical recycling enables the separation of combined materials and plastics within a single packaging item. This capability allows for a more efficient recycling process and the recovery of valuable components.

  • Expanded possibilities for recycled packaging in the food sector: Chemical recycling provides greater opportunities for utilizing recycled materials in food packaging. By altering the chemical structure of plastics, it becomes possible to produce high-quality recyclate suitable for packaging food products, meeting safety and regulatory requirements.


Why additives are important in plastic recycling?


The recycling sector is gaining increasing importance in society, with a growing interest in specialty additives for plastic recycling. These additives not only facilitate the recycling process but also help enhance the performance characteristics of certain recyclates. In fact, some recyclates can achieve superior qualities compared to virgin products. This concept is known as upcycling, where materials are upgraded rather than downgraded. Below is a table representing the common plastic additives for virgin and recycled plastic materials.

Additive  Function 
UV Inhibitors Protect plastic products from UV light and prevent chemical degradation caused by sunlight exposure
Impact Modifiers Improve impact resistance, making plastics more durable, less brittle, and less prone to cracking
Pigments Added to achieve specific product colors by mixing with the base plastic raw material
Compatibilizers Used to increase stability and mechanical properties of recycled plastic blends, ensuring consistent product quality
Stabilizing Agents Added to prevent degradation and improve the mechanical properties of recycled plastics, maintaining product specifications


Examples of functional additives enhancing polymer recycling


  1. Functional additives for high-quality PET recycling — PET is a recyclable plastic with distinct advantages. Mechanical recycling of PET is cost-effective and yields uncontaminated pellets. However, PET recyclates have had limited applications due to low melt strength. BASF's functional additives, like Joncryl® ADR, address this issue. They repair broken polymer chains, restoring melt strength and enabling the production of high-grade packaging materials. These additives also create new properties, such as increased tensile strength, expanding the possibilities for recycled PET in various applications.

  2. Increased aging and weatherability resistance — BASF offers a range of additives designed to facilitate the recycling of plastics. Joncryl® ADR is just one example. The Recyclostab® line enhances the processing stability and aging resistance of polyolefins, enabling the recycling of LDPE films and automotive battery casings. Recycloblend® products are ideal for recycling PP/EPDM bumpers, while Recyclossorb® enhances the weatherability of polyolefins, allowing for outdoor use of recyclates.

  3. Petra® 7030 — High-performance recycled PET in the USA — BASF introduces Petra® 7030, a unique easy-flow injection-molding PET with 30% glass fiber content, exclusively available in the USA. This innovative material combines exceptional strength, stiffness, and dimensional stability. It offers low creep and excellent high-temperature properties. Thanks to its superior flow properties, products made from Petra® 7030 exhibit a high-quality surface finish, eliminating the need for painting.

Download Brochure CirKular+™ Solutions for Plastics Upcycling and Circular Economy by Kraton.


What are the regulations that govern plastic recycling?


European strategy to tackle the plastic waste problem


EC Logo Plastics are often used only once and then discarded, causing pollution and economic loss. Europe faces a loss of 70-105 Bn Euros due to the limited value retained in plastic packaging. The long decomposition time and massive ocean pollution from unrecycled plastics demand a joint European response. Currently, most plastic in Europe is landfilled or incinerated instead of being recycled.

The EU has taken initial steps to combat plastic waste, but the European strategy aims to ensure all plastic packaging is reusable or recyclable by 2030. This strategy aligns with Europe's goals for a low-carbon and circular economy and contributes to sustainable development and climate agreements.


Contribution to the circular economy


The European Commission has been actively promoting the transition to a circular economy, and the plastics strategy is an integral part of these efforts. In 2015, the EU adopted the action plan for the circular economy, signaling its commitment to transforming the economy and creating new business opportunities. In line with this, new waste rules were proposed and agreed upon, including:

  • a target of 55% recycling for plastic packaging waste by 2030,
  • a ban on landfilling separately collected waste, and
  • stronger arrangements for extended producer responsibility (EPR) schemes.

The plastics strategy aligns with these measures and supports the EU's goal of achieving a circular economy.


Changes for the plastic industry and value chain


By 2030, all plastic packaging must be recyclable or reusable. The European Commission will revise legislative requirements, focusing on recyclability in design. The goal is to reduce waste, prevent littering, and address over-packaging. Quality standards for sorted plastic waste and recycled plastics will be developed. Packaging producers will receive support for sustainability and circular practices. Improved Extended Producer Responsibility schemes will incentivize innovation. The plastics industry is encouraged to participate and support the pledge for 10 million tons of recycled plastics in new products by 2025.


Funds provided by the commission for the plastic strategy


The plastics strategy requires significant investments in research and innovation. Existing EU funding sources, such as Structural Funds, The European Fund for Strategic Investments, Circular Economy Finance Support Platform, and Horizon 2020 will support businesses and Member States in advancing recyclable plastics and upgrading waste management infrastructure.

Horizon 2020 has already allocated over €250 million for relevant R&D, with an additional €100 million dedicated to priority actions until 2020. The Commission will develop a Strategic Research Innovation Agenda for plastics, covering production, use, and environmental and health impacts. Furthermore, stakeholders will collaborate to explore the potential of a privately led fund for financing investments in innovative solutions and technologies to mitigate the negative impact of primary plastic production.


RecyClass protocol for assessing plastic packaging recyclability


RecyClass Certification The RecyClass Protocol is a guidance document developed by RecyClass, an initiative led by Plastics Recyclers Europe (PRE), to assess the recyclability of plastic packaging. It provides a standardized methodology for evaluating the design and composition of plastic packaging in terms of its recyclability and compatibility with existing recycling processes. The protocol helps packaging designers, manufacturers, and recyclers determine the potential recyclability of a specific packaging design. It considers various factors such as:

  • the type of plastic used,
  • the thickness, color, and shape of the plastic, and
  • the presence of additives or other materials.

By following the RecyClass protocol, stakeholders can assess whether a packaging design can be effectively sorted, processed, and recycled within existing recycling facilities. The evaluation conducted using the RecyClass Protocol results in a recyclability rating, indicating the level of compatibility with current recycling practices.

The rating provides valuable feedback to packaging producers, enabling them to make informed decisions to improve the recyclability of their products. It also promotes the use of packaging designs that are more environmentally friendly and compatible with circular economy principles. The RecyClass Protocol plays a crucial role in advancing the recycling of plastic packaging and promoting a more sustainable approach to plastic waste management.


Explore the Complete Range of Recyclable Polymers


View all commercially available recyclable polymers in the market, analyze the technical data of each product, get technical assistance, or request samples.



References

  1. https://chemistry.berkeley.edu/news
  2. Which Plastic Can Be Recycled? | Plastics For Change
  3. Leveling the cost and carbon footprint of circular polymers that are chemically recycled to monomer | Science Advances
  4. Additives for mechanical plastic recycling
  5. Plastic Recycling Technology: What are the Environmental Benefits?
  6. https://www.bpf.co.uk/Sustainability/Plastics_Recycling

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