Plastics : Recycled plastic, its quality and its usage

Recycled plastics are materials that have been collected, processed, and remanufactured from used plastic products or waste. The process involves collecting, sorting, cleaning, shredding, melting, and reforming plastic materials to create new products.

Quality Levels and Grades:

Virgin-Like Quality:

• The highest grade of recycled plastic
• It has a minimal degradation from the original properties
• It usually comes from single-stream, clean post-industrial waste
• It is suitable for food-grade applications when properly processed
• It is often used in bottle-to-bottle recycling

Post-industrial waste refers to manufacturing and industrial scrap or waste materials that never reached consumers. It's the waste generated during the production of goods

Medium Grade:

• It suffers a slight reduction in mechanical properties
• It may have minor color variations
• It is more suitable for non-food contact applications
• It is common in construction and automotive parts
• It is often from mixed consumer waste

Plastic mechanical properties are the key characteristics that describe how plastic materials behave when subjected to different forces and conditions.

Lower Grade:

• It has significant property changes from the raw virgin material
• It has color inconsistencies
• It has a limited mechanical strength
• It is used in less demanding applications
• It often comes from heavily mixed or contaminated sources

Quality Factors Affecting Recycled Plastics:

Source Material Quality:

• Clean, single-type plastics yield better quality
• The contamination reduces final quality
• Food residue in plastic containers can create processing challenges
• The chemical residues may affect properties

Processing Method:

• Mechanical recycling: most commonly used, it maintains a reasonable quality
• Chemical recycling: It can produce virgin-like quality
• Heat exposure : using it during the recycling process can degrade the properties
• Additives : they may be needed to enhance the properties of the recycled material

Number of Recycling Cycles:

• Each recycling cycle typically degrades properties
• The chain length of polymers decreases
• The mechanical properties may get degraded
• The color and clarity often deteriorate

Chain length of polymers refers to how many repeating molecular units (monomers) are linked together in a plastic molecule.

 

Common Applications of recycled material:

High-Quality Applications:

• Beverage bottles (PET)
• Food packaging
• Medical supply containers
• High-end consumer goods
• Automotive interior parts

Medium-Quality Applications:

• Construction materials
• Garden furniture
• Industrial packaging
• Automotive parts (non-critical)
• Consumer goods

Lower-Quality Applications:

• Park benches
• Traffic barriers
• Industrial pallets
• Outdoor furniture

Environmental and economic considerations:

Environmental benefits:

• Recycling helps reduce the landfill waste
• It has a lower carbon footprint compared to virgin plastic
• It decreases dependency on fossil fuels
• It reduces ocean plastic pollution

Economic factors:

• Market prices fluctuate with oil prices
• Processing costs of recycled plastic can be significant

Market trends:

• Increasing demand for recycled content
• Government regulations supporting recycled materials
• Growing consumer awareness
• Investment in recycling infrastructure

Best practices for using recycled plastics:

Material Selection:

• We need to choose appropriate plastic grade adequate for the application (food grade, medical grade, ...)
• Take into account the property variations
• Take the color inconsistencies into account

This comprehensive understanding of recycled plastics may help in making informed decisions about their use in various applications while considering quality requirements and environmental impact.