Multilayer PET Recycling Composition for Material Compatibility
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Solution Overview
Problem
The incompatibility of materials in multilayer PET containers prevents mechanical recycling, leading to significant waste accumulation and environmental issues, as current recycling methods are optimized for homogeneous PET and multilayer fractions contaminate other polymer fractions, resulting in 15-20% of multilayer waste being landfilled or incinerated annually.
Innovation Solution
A method involving cleaning, crushing, and mixing multilayer PET containers with a compatibilizing mixture of thermoplastic polyolefin matrix, plant-derived reagents, and rosin-based tackifier to create a mechanically processable recycled material, allowing for mechanical recycling without chemical treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multilayer PET containers are mechanically recycled directly, then recycling process is simple, but material incompatibility between layers prevents successful recycling
Solution Approach 1:
The patent introduces a compatibilizing mixture as an intermediary substance that facilitates bonding between incompatible polymer layers. This mixture contains a polyolefin matrix (10-45% by weight) that acts as a binding agent, along with coupling agents (1-10% by weight) and processing aids (1-10% by weight), enabling mechanical recycling of multilayer PET containers that would otherwise be incompatible for direct recycling
Solution Approach 2:
The patent creates a composite recycled material by combining multilayer PET container fragments with the compatibilizing mixture in specific ratios (50-85% multilayer PET, 10-45% polyolefin matrix, 1-10% coupling agents, 1-10% processing aids). This composite approach allows the heterogeneous multilayer structure to be processed mechanically as a unified material while maintaining structural integrity
2Reliability
If chemical recycling is used for multilayer PET containers, then material compatibility issues are resolved, but environmental impact increases and profitability decreases
Solution Approach 1:
The patent replaces chemical recycling methods with a mechanical recycling process enhanced by a compatibilizing mixture. Instead of using chemical solvents or high-temperature processing that would degrade materials and increase environmental impact, the invention uses mechanical mixing and extrusion at controlled temperatures (150-250°C) with a formulation designed for mechanical compatibility, thereby eliminating the need for chemical recycling while maintaining material integrity
3Manufacturing precision
If multilayer PET containers are separated into fractions, then contamination of other polymer fractions is prevented, but recovery rate decreases due to 15-20% multilayer fraction
Solution Approach 1:
The patent creates a universal recycling solution that handles multiple polymer types simultaneously through the compatibilizing mixture. The polyolefin matrix (10-45% by weight) serves as a universal binding agent that is compatible with various polymer layers (PET, EVOH, LDPE, etc.), allowing the previously problematic 15-20% multilayer fraction to be recycled alongside other polymer fractions without causing contamination, thereby increasing overall recovery rate while maintaining separation purity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces a homogenous recycled material suitable for conventional plastic transformation techniques, reducing chemical recycling needs and increasing profitability in multilayer PET recovery.
Implementation Method 1
a compatibilising mixture formed by a thermoplastic polyolefin matrix, a reagent of plant origin, and a tackifier
Implementation Method 2
compatibilising mixture formed by a thermoplastic polyolefin matrix, a reagent of plant origin, and a tackifier
Implementation Method 3
cleaning the multilayer PET containers to eliminate smell and certain impurities. A soapy solution is used in the cleaning step
Implementation Method 4
crushing the clean multilayer PET material to a size of at least 1 mm
Implementation Method 5
mixing the clean crushed multilayer PET material in a percentage of 50% to 85% of the total mixture, with a compatibilising mixture
Implementation Method 6
mixing the clean crushed multilayer PET material with a compatibilising mixture
Implementation Method 7
melting the mixture obtained in the preceding step by means of extrusion at a temperature of between 200°C and 300°C
Implementation Method 8
melting the mixture obtained in the preceding step by means of extrusion at a temperature of between 200°C and 300°C to obtain a continuous filament
Data Source
AI summary
A method for obtaining mechanically recoverable recycled material from multilayer PET (polyethylene terephthalate) containers of post-consumer and/or post-industrial origin involves cleaning the containers, crushing them into pieces, mixing the pieces with a compatibilizing mixture and melting the mixed product to obtain a continuous filament. The compatibilising mixture is formed by at least: 10-45% thermoplastic polyolefin matrix; a reagent of plant origin in a percentage of less than 7.5% of the total mixture; and a rosin-based tackifier in a percentage of less than 7.5% of the total mixture.